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Sample records for dynamic positioning

  1. Identification of Dynamically Positioned Ships

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1996-04-01

    Full Text Available Todays model-based dynamic positioning (DP systems require that the ship and thruster dynamics are known with some accuracy in order to use linear quadratic optical control theory. However, it is difficult to identify the mathematical model of a dynamically posititmed (DP ship since the ship is not persistently excited under DP. In addition the ship parameter estimation problem is nonlinear and multivariable with only position and thruster state measurements available for parameter estimation. The process and measurement noise must also be modeled in order to avoid parameter drift due to environmental disturbances and sensor failure. This article discusses an off-line parallel extended Kalman filter (EKF algorithm utilizing two measurement series in parallel to estimate the parameters in the DP ship model. Full-scale experiments with a supply vessel are used to demonstrate the convergence and robustness of the proposed parameter estimator.

  2. Analysis of modern positioning systems, used for dynamic positioning purposes

    OpenAIRE

    2016-01-01

    This article contains the detailed analysis of the modern position systems used for dynamic positioning basing on their expediency perspective. The accuracy issue related to determining vessel’s positions using dynamic positioning has been contemplated. The analysis included not only advantages but disadvantages of each determining position system as well summarizing the results for further consideration and possible application purposes. The accuracy of ship’s positioning using the dynamic p...

  3. Play and Positive Group Dynamics

    Science.gov (United States)

    Thompson, Pam; White, Samantha

    2010-01-01

    Play is an important part of a child's life and essential to learning and development (Vygotsky, 1978). It is vital that students participate in play and that play be conducted in a restorative manner. Play allows a variety of group dynamics to emerge. Irvin Yalom (1995) identifies 11 curative factors of the group experience. These factors include…

  4. SLAM - Based Approach to Dynamic Ship Positioning

    Directory of Open Access Journals (Sweden)

    Krzysztof Wrobel

    2014-03-01

    Full Text Available Dynamically positioned vessels, used by offshore industry, use not only satellite navigation but also different positioning systems, often referred to as reference' systems. Most of them use multiple technical devices located outside the vessel which creates some problems with their accessibility and performance. In this paper, a basic concept of reference system independent from any external device is presented, basing on hydroacoustics and Simultaneous Localization and Mapping (SLAM method. Theoretical analysis of its operability is also performed.

  5. Intelligent control algorithm for ship dynamic positioning

    Directory of Open Access Journals (Sweden)

    Meng Wang

    2014-12-01

    Full Text Available Ship motion in the sea is a complex nonlinear kinematics. The hydrodynamic coefficients of ship model are very difficult to accurately determine. Establishing accurate mathematical model of ship motion is difficult because of changing random factors in the marine environment. Aiming at seeking a method of control to realize ship positioning, intelligent control algorithms are adopt utilizing operator's experience. Fuzzy controller and the neural network controller are respectively designed. Through simulations and experiments, intelligent control algorithm can deal with the complex nonlinear motion, and has good robustness. The ship dynamic positioning system with neural network control has high positioning accuracy and performance.

  6. Wave disturbance filtering in dynamic positioning systems

    Directory of Open Access Journals (Sweden)

    Tor S. Schei

    1996-04-01

    Full Text Available Three different approaches to wave disturbance filtering in dynamic positioning systems are studied in this paper. It is shown that a conventional design based on notch filters leads to approximately the same achievable performance of the total control system as can be achieved with an observer based design. It is also shown that a proposed passivity based design leads to a conventional filter with PD-controller. However, there is a relation between the parameters in the filter and the PD-controller, which ensures the passivity properties of the control system.

  7. Dynamics of Cosmological Perturbations in Position Space

    CERN Document Server

    Bashinsky, S V; Bashinsky, Sergei; Bertschinger, Edmund

    2002-01-01

    We show that the linear dynamics of cosmological perturbations can be described by coupled wave equations, allowing their efficient numerical and, in certain limits, analytical integration directly in position space. The linear evolution of any perturbation can then be analyzed with the Green's function method. Prior to hydrogen recombination, assuming tight coupling between photons and baryons, neglecting neutrino perturbations, and taking isentropic (adiabatic) initial conditions, the obtained Green's functions for all metric, density, and velocity perturbations vanish beyond the acoustic horizon. At the acoustic wavefronts, a positive gravitational potential perturbation produces narrow photon-baryon density spikes, which provide one of the major contributions to the observed cosmic microwave background radiation anisotropy on all scales. The gravitational interaction between cold dark matter and baryons causes a dip in the observed temperature of the radiation at the center of the initial perturbation. We...

  8. Pushing the envelope[Dynamic positioning

    Energy Technology Data Exchange (ETDEWEB)

    DeLuca, Marshall

    2000-11-01

    The selection of dynamic positioning as opposed to conventional mooring in the latest deepwater rigs is examined. Details are given of the use of pre-installed mooring systems in conjunction with suction anchors in advance of operations. The development and testing by Shell with assistance from contractors of suction anchors that can be easily retrieved and the patented subsea connector system designed by Delmar for connecting the suction anchor and the deployment line and eventually the mooring line are described, and use of the new system by Shell and Delmar to move the Transocean Marianas in the Mississippi Canyon block is reported. The next generation of mooring technology using synthetic components such as polyester rope, and long-term or permanent mooring for floating production systems are discussed. A diagram of the subsea connector is presented.

  9. Understanding positivity within dynamic team interactions: A statistical discourse analysis

    OpenAIRE

    Lehmann-Willenbrock, N.K.; Chiu, M.M.; Lei, Z.; Kauffeld, S.

    2017-01-01

    Positivity has been heralded for its individual benefits. However, how positivity dynamically unfolds within the temporal flow of team interactions remains unclear. This is an important oversight, as positivity can be key to team problem-solving and performance. In this study, we examine how team micro-processes affect the likelihood of positivity occurring within dynamic team interactions. In doing so, we build on and expand previous work on individual positivity and integrate theory on temp...

  10. Positive dynamical systems in discrete time theory, models, and applications

    CERN Document Server

    Krause, Ulrich

    2015-01-01

    This book provides a systematic, rigorous and self-contained treatment of positive dynamical systems. A dynamical system is positive when all relevant variables of a systemare nonnegative in a natural way. This is in biology, demography or economics, where the levels of populations or prices of goods are positive. The principle also finds application in electrical engineering, physics and computer sciences.

  11. Dynamic aspects of segmented mirror position control

    Science.gov (United States)

    Kaercher, Hans J.

    2006-02-01

    Extreme large optical telescopes will operate in an open environment and may be excited by wind effects. The position control of the mirror segments may need fast control, and the position actuators and the related control loops may be separated in a conventional slow, iso-static and a fast reaction-mass type system. There exists some experience with wind excitations of airborne telescopes, e.g. the Stratospheric Observatory for Infrared Astronomy SOFIA. The pointing control system of that telescope is equipped with several dedicated design features, as a vibration isolations system, a flexible body control system and an active mass damper system to handle excitations in different frequency ranges. These features may be transferred to the position control systems of segmented mirrors. The paper will give some system engi-neers recommendations for designing those systems.

  12. Understanding positivity within dynamic team interactions: A statistical discourse analysis

    NARCIS (Netherlands)

    Lehmann-Willenbrock, N.K.; Chiu, M.M.; Lei, Z.; Kauffeld, S.

    2016-01-01

    Positivity has been heralded for its individual benefits. However, how positivity dynamically unfolds within the temporal flow of team interactions remains unclear. This is an important oversight, as positivity can be key to team problem-solving and performance. In this study, we examine how team mi

  13. Understanding positivity within dynamic team interactions: A statistical discourse analysis

    NARCIS (Netherlands)

    Lehmann-Willenbrock, N.K.; Chiu, M.M.; Lei, Z.; Kauffeld, S.

    2017-01-01

    Positivity has been heralded for its individual benefits. However, how positivity dynamically unfolds within the temporal flow of team interactions remains unclear. This is an important oversight, as positivity can be key to team problem-solving and performance. In this study, we examine how team mi

  14. Impact of positivity and complete positivity on accessibility of Markovian dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Raffaele [Department of Mathematics, Iowa State University, Ames, IA 50011 (United States)

    2005-10-14

    We consider a two-dimensional quantum control system evolving under an entropy-increasing irreversible dynamics in the semigroup form. Considering a phenomenological approach to the dynamics, we show that the accessibility property of the system depends on whether its evolution is assumed to be positive or completely positive. In particular, we characterize the family of maps having different accessibilities and show the impact of that property on observable quantities by means of a simple physical model.

  15. Quantum dynamical semigroups and non-decomposable positive maps

    Energy Technology Data Exchange (ETDEWEB)

    Benatti, Fabio; Floreanini, Roberto; Piani, Marco

    2004-06-07

    We study dynamical semigroups of positive, but not completely positive maps on finite-dimensional bipartite systems and analyze properties of their generators in relation to non-decomposability and bound-entanglement. An example of non-decomposable semigroup leading to a (4x4)-dimensional bound-entangled density matrix is explicitly obtained.

  16. Dynamic Positioning of Ships: A nonlinear control design study

    NARCIS (Netherlands)

    Muhammad, S.

    2012-01-01

    Dynamic positioning (DP) is relatively a new technique used to maintain the position and heading of ships in various offshore operations. Due to the features like better safety and operating efficiency, DP systems are becoming more and more popular. This thesis mainly focusses on the control system

  17. Equilibrium Positions for UAV Flight by Dynamic Soaring

    Directory of Open Access Journals (Sweden)

    Bingjie Zhu

    2015-01-01

    Full Text Available Dynamic soaring is a special flying technique designed to allow UAVs (unmanned aerial vehicles to extract energy from wind gradient field and enable UAVs to increase the endurance. In order to figure out the energy-extraction mechanisms in dynamic soaring, a noninertial wind relative reference frame of aircraft is built. In the noninertial frame, there is an inertial force which is created by gradient wind field. When the wind gradient (GW and the components of airspeed (vzvx are positive, inertial force (F makes positive work to the aircraft. In the meantime, an equilibrium position theory of dynamic soaring is proposed. At the equilibrium positions, the increased potential energy is greater than the wasted kinetic energy when the aircraft is flying upwards. The mechanical energy is increased in this way, and the aircraft can store energy for flight. According to the extreme value theory, contour line figures of the maximum function and the component of airspeed (vz are obtained to find out the aircraft’s lifting balance allowance in dynamic soaring. Moreover, this equilibrium position theory can also help to conduct an aircraft to acquire energy from the environment constantly.

  18. Nonlineat observer-controller design for dynamic positioning of ships

    Institute of Scientific and Technical Information of China (English)

    何黎明; 田作华; 施颂椒

    2004-01-01

    The main focus is nonlinear model-based dynamic positioning (DP) control system design. A nonlinear uniform global exponential stability (UGES) observer produces noise-free estimates of the position, the slowly varying environmental disturbances and the velocity, which are used in a proportional-derivative (PD) + feedforward control law. The stability of this observer-controller system is proved by introducing a specific nonlinear cascaded system. The simulation results have successfully demonstrated the performance of designed DP control system.

  19. Dynamics of social positioning patterns in group-robot interactions

    OpenAIRE

    Vroon, Jered; Joosse, Michiel; Lohse, Manja; Kolkmeier, Jan; Kim, Jaebok; Truong, Khiet; Englebienne, Gwenn; Heylen, Dirk; Evers, Vanessa

    2015-01-01

    When a mobile robot interacts with a group of people, it has to consider its position and orientation. We introduce a novel study aimed at generating hypotheses on suitable behavior for such social positioning, explicitly focusing on interaction with small groups of users and allowing for the temporal and social dynamics inherent in most interactions. In particular, the interactions we look at are approach, converse and retreat. In this study, groups of three participants and a telepresence r...

  20. A UT positioning approach for dynamic satellite constellations

    Science.gov (United States)

    Zhao, W.; Tafazolli, R.; Evans, B. G.

    1995-01-01

    In this paper, we discuss a new positioning scheme which is thought to be applicable for dynamic satellite constellations. We begin with the introduction of our filter model which is based on stochastic process and filtering theory. Then, simulation results of the technique are presented based on a LEO constellation and some of the IRIDIUM system parameters. Performance of this algorithm is investigated under various noise conditions. Finally, several applications of this UT (user terminal) positioning algorithm are discussed.

  1. Dynamics of serial position change in probe-recognition task

    Directory of Open Access Journals (Sweden)

    Fifić Mario

    2002-01-01

    Full Text Available Relationship between practice and serial position effects was investigated, in order to obtain more evidence for underlying short-term memory processes. The investigated relationship is termed the dynamics of serial position change. To address this issue, the present study investigated mean latency, errors, and performed Ex-Gaussian convolution analysis. In six-block trials the probe-recognition task was used in the so-called fast experimental procedure. The serial position effect was significant in all six blocks. Both primacy and recency effects were detected, with primacy located in the first two blocks, producing a non-linear serial position effect. Although the serial position function became linear from the third block on, the convolution analysis revealed a non-linear change of the normal distribution parameter, suggesting special status of the last two serial positions. Further, separation of convolution parameters for serial position and practice was observed, suggesting different underlying mechanisms. In order to account for these findings, a strategy shift mechanism is suggested, rather then a mechanism based on changing the manner of memory scanning. Its influence is primarily located at the very beginning of the experimental session. The pattern of results of errors regarding the dynamics of serial position change closely paralleled those on reaction times. Several models of short-term memory were evaluated in order to account for these findings.

  2. Positive explorers: modeling dynamic control in normal aging.

    Science.gov (United States)

    Glass, Brian D; Osman, Magda

    2017-01-01

    Situations in which there are multiple changes occurring all at once and which demand complex decisions to be made are common throughout life, but little is known about how normal aging influences performance on these types of scenarios. To determine performance differences associated with normal aging, we test older and younger adults in a dynamic control task. The task involves the control of a single output variable over time via multiple and uncertain input controls. The Single Limited Input, Dynamic Exploratory Responses (SLIDER) computational model, is implemented to determine the behavioral characteristics associated with normal aging in a dynamic control task. Model-based analysis demonstrates a unique performance signature profile associated with normal aging. Specifically, older adults exhibit a positivity effect in which they are more influenced by positively valenced feedback, congruent with previous research, as well as enhanced exploratory behavior.

  3. Dynamics of Nucleosome Positioning Maturation following Genomic Replication

    Directory of Open Access Journals (Sweden)

    Pauline Vasseur

    2016-09-01

    Full Text Available Chromatin is thought to carry epigenetic information from one generation to the next, although it is unclear how such information survives the disruptions of nucleosomal architecture occurring during genomic replication. Here, we measure a key aspect of chromatin structure dynamics during replication—how rapidly nucleosome positions are established on the newly replicated daughter genomes. By isolating newly synthesized DNA marked with 5-ethynyl-2′-deoxyuridine (EdU, we characterize nucleosome positions on both daughter genomes of S. cerevisiae during chromatin maturation. We find that nucleosomes rapidly adopt their mid-log positions at highly transcribed genes, which is consistent with a role for transcription in positioning nucleosomes in vivo. Additionally, experiments in hir1Δ mutants reveal a role for HIR in nucleosome spacing. We also characterized nucleosome positions on the leading and lagging strands, uncovering differences in chromatin maturation dynamics at hundreds of genes. Our data define the maturation dynamics of newly replicated chromatin and support a role for transcription in sculpting the chromatin template.

  4. Tuning positive feedback for signal detection in noisy dynamic environments.

    Science.gov (United States)

    Johansson, Anders; Ramsch, Kai; Middendorf, Martin; Sumpter, David J T

    2012-09-21

    Learning from previous actions is a key feature of decision-making. Diverse biological systems, from neuronal assemblies to insect societies, use a combination of positive feedback and forgetting of stored memories to process and respond to input signals. Here we look how these systems deal with a dynamic two-armed bandit problem of detecting a very weak signal in the presence of a high degree of noise. We show that by tuning the form of positive feedback and the decay rate to appropriate values, a single tracking variable can effectively detect dynamic inputs even in the presence of a large degree of noise. In particular, we show that when tuned appropriately a simple positive feedback algorithm is Fisher efficient, in that it can track changes in a signal on a time of order L(h)=(|h|/σ)(-2), where |h| is the magnitude of the signal and σ the magnitude of the noise.

  5. Indoor dynamic positioning system based on strapdown inertial navigation technology

    Science.gov (United States)

    Xing, YaDong; Wu, Hong

    2011-11-01

    Strapdown inertial navigation technology, which is widely used in aerospace, is a navigation technology in which the gyros sensor and accelerometers sensor are rigidly attached to the body of the object. This article describes an application of strapdown inertial navigation technology in indoor dynamic positioning system. The hardware design of the node include the master controller, data collection, sensors, antenna and related peripheral circuit. Positioning algorithm, data acquisition and transmission are done by software programming based on the hardware circuit. The strapdown inertial navigation composed of the hardware and the software could calculate the position of the object. Simulation software(matlab) is used to confirm the correctness of the positioning algorithm which is implemented by software programming in the system. The system uses the wireless sensor network to expand the range of the positioning. The system of which the information transmission is reliable and the mobility is strongly can satisfy the requirements of the emergency.

  6. Dynamic positive feedback source-coupled logic (D-PFSCL)

    Science.gov (United States)

    Gupta, Kirti; Pandey, Neeta; Gupta, Maneesha

    2016-10-01

    This paper presents dynamic positive feedback source-coupled logic (D-PFSCL) style which is derived from positive feedback source-coupled logic (PFSCL). The proposed logic style uses dynamic current source in contrast to constant current source of PFSCL to attain lower power consumption. Two techniques for D-PFSCL style-based multistage applications are suggested. Several D-PFSCL gates are simulated and compared with the respective PFSCL counterparts through SPICE simulations by using Taiwan semiconductor manufacturing company 0.18 µm CMOS technology parameters. A maximum power reduction of 84% is achieved for D-PFSCL gates. The effect of process variation on the power consumption of the D-PFSCL gates shows a maximum variation factor of 1.5 between the best and the worst cases.

  7. The complex dynamics of wishful thinking: The critical positivity ratio

    CERN Document Server

    Brown, Nicholas J L; Friedman, Harris L

    2013-01-01

    We examine critically the claims made by Fredrickson and Losada (2005) concerning the construct known as the "positivity ratio". We find no theoretical or empirical justification for the use of differential equations drawn from fluid dynamics, a subfield of physics, to describe changes in human emotions over time; furthermore, we demonstrate that the purported application of these equations contains numerous fundamental conceptual and mathematical errors. The lack of relevance of these equations and their incorrect application lead us to conclude that Fredrickson and Losada's claim to have demonstrated the existence of a critical minimum positivity ratio of 2.9013 is entirely unfounded. More generally, we urge future researchers to exercise caution in the use of advanced mathematical tools such as nonlinear dynamics and in particular to verify that the elementary conditions for their valid application have been met.

  8. Ancrage dynamique: principales applications Dynamic Positioning: Main Applications

    Directory of Open Access Journals (Sweden)

    Fay H.

    2006-11-01

    Full Text Available L'ancrage dynamique est la technique qui a permis à la recherche pétrolière d'étendre ses possibilités bien au-delà des plateaux continentaux, sans limitation de profondeur, pour des opérations difficiles, ou encore dans un environnement océanométéorologique sévère, comme celui de la mer du Nord et des mers froides avec la présence d'icebergs. Cet article correspond à des extraits de l'ouvrage Ancrage dynamique. Technique et applications , à paraître aux Editions Technip. Après un bref rappel historique et un exposé succinct des caractéristiques des systèmes d'ancrage dynamique, les principales réalisations de navires et de plates-formes semi-submersibles équipées d'un ancrage dynamique sont présentées. La précision du maintien en position, ainsi que les limites opérationnelles des supports considérés sont de même exposées. Enfin la conclusion retrace les avantages de ce procédé, dont l'exceptionnel développement s'applique aussi aux domaines scientifiques et militaires, ainsi qu'à d'autres secteurs industriels que celui des hydrocarbures. Dynamic positioning is the technique that has enabled oil exploration to extend its possibilities far beyond continental shelves, without any limitation of water depth, for difficult operations or else in harsh environments such as for the North Sea and arctic zones with the presence of icebergs. This paper consists of extracts from the book Dynamic Positioning. Technique and Applications , to be published by Editions Technip. After a brief historical review and a succinct survey of the characteristics of dynamic positioning systems, the principal realizations of ships and semi-submersible platforms equipped with a dynamic positioning system are described. The accuracy of position holding capability as well as the operational limits of the supports considered are also described. The conclusion reviews the advantages of this technique, whose exceptional development also

  9. Dynamic positioning system based on active disturbance rejection technology

    Science.gov (United States)

    Lei, Zhengling; Guo, Chen; Fan, Yunsheng

    2015-08-01

    A dynamically positioned vessel, by the International Maritime Organization (IMO) and the certifying class societies (DNV, ABS, LR, etc.), is defined as a vessel that maintains its position and heading (fixed location or pre-determined track) exclusively by means of active thrusters. The development of control technology promotes the upgrading of dynamic positioning (DP) systems. Today there are two different DP systems solutions available on the market: DP system based on PID regulator and that based on model-based control. Both systems have limited disturbance rejection capability due to their design principle. In this paper, a new DP system solution is proposed based on Active Disturbance Rejection Control (ADRC) technology. This technology is composed of Tracking-Differentiator (TD), Extended State Observer (ESO) and Nonlinear Feedback Combination. On one hand, both TD and ESO can act as filters and can be used in place of conventional filters; on the other hand, the total disturbance of the system can be estimated and compensated by ESO, which therefore enhances the system's disturbance rejection capability. This technology's advantages over other methods lie in two aspects: 1) This method itself can not only achieve control objectives but also filter noisy measurements without other specialized filters; 2) This method offers a new useful approach to suppress the ocean disturbance. The simulation results demonstrate the effectiveness of the proposed method.

  10. Generalized Master Equations Leading to Completely Positive Dynamics

    Science.gov (United States)

    Vacchini, Bassano

    2016-12-01

    We provide a general construction of quantum generalized master equations with a memory kernel leading to well-defined, that is, completely positive and trace-preserving, time evolutions. The approach builds on an operator generalization of memory kernels appearing in the description of non-Markovian classical processes and puts into evidence the nonuniqueness of the relationship arising due to the typical quantum issue of operator ordering. The approach provides a physical interpretation of the structure of the kernels, and its connection with the classical viewpoint allows for a trajectory description of the dynamics. Previous apparently unrelated results are now connected in a unified framework, which further allows us to phenomenologically construct a large class of non-Markovian evolutions taking as the starting point collections of time-dependent maps and instantaneous transformations describing the microscopic interaction dynamics.

  11. Dynamic X-ray diffraction sampling for protein crystal positioning.

    Science.gov (United States)

    Scarborough, Nicole M; Godaliyadda, G M Dilshan P; Ye, Dong Hye; Kissick, David J; Zhang, Shijie; Newman, Justin A; Sheedlo, Michael J; Chowdhury, Azhad U; Fischetti, Robert F; Das, Chittaranjan; Buzzard, Gregery T; Bouman, Charles A; Simpson, Garth J

    2017-01-01

    A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction, significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Using in situ two-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by

  12. Dynamic Beam Based Calibration of Beam Position Monitors

    CERN Document Server

    Dehning, Bernd; Galbraith, Peter; Mugnai, G; Placidi, Massimo; Sonnemann, F; Tecker, F A; Wenninger, J

    1998-01-01

    The degree of spin polarization at LEP is strongly dependent on the knowledge of the vertical orbit. Quadrupole magnet alignment and beam position monitor (BPM) offsets are the main source of the orbi t uncertainty. The error of the orbit monitor readings can be largely reduced by calibrating the monitor relative to the adjacent quadrupole. At LEP, 16 BPM offsets can be determined in parallel durin g 40 minutes. The error of the measure offset is about 30mm. During the LEP run 1997, more than 500 measurements were made and used for the optimisation of polarization. The method of dynamic beam bas ed calibration will be explained and the results will be shown.

  13. VST telescope dynamic analisys and position control algorithms

    CERN Document Server

    Schipani, P

    2001-01-01

    The VST (VLT Survey Telescope) is a 2.6 m class Alt-Az telescope to be installed on Cerro Paranal in the Atacama desert, Northern Chile, in the European Southern Observatory (ESO) site. The VST is a wide-field imaging facility planned to supply databases for the ESO Very Large Telescope (VLT) science and carry out stand-alone observations in the UV to I spectral range. So far no telescope has been dedicated entirely to surveys; the VST will be the first survey telescope to start the operation, as a powerful survey facility for the VLT observatory. This paper will focus on the axes motion control system. The dynamic model of the telescope will be analyzed, as well as the effect of the wind disturbance on the telescope performance. Some algorithms for the telescope position control will be briefly discussed.

  14. 77 FR 62247 - Dynamic Positioning Operations Guidance for Vessels Other Than Mobile Offshore Drilling Units...

    Science.gov (United States)

    2012-10-12

    ...] Dynamic Positioning Operations Guidance for Vessels Other Than Mobile Offshore Drilling Units Operating on... voluntary guidance titled ``Mobile Offshore Drilling Unit Dynamic Positioning Guidance''. The notice recommended owners and operators of Mobile Offshore Drilling Units (MODUs) follow Marine Technology...

  15. The dynamic origins of positive health and wellbeing

    Science.gov (United States)

    Cloninger, C. Robert; Salloum, Ihsan M.; Mezzich, Juan E.

    2015-01-01

    The causes of wellbeing and illbeing interact with feedback dynamics resulting in the same set of traits giving rise to a variety of health outcomes (multi-finality) and different traits giving rise to the same health outcome (equi-finality). As a result, a full understanding of health and its disorders must be in terms of a complex adaptive system of causes, rather than in terms of categorical diagnoses or sets of symptoms. The three domains of person-centered integrative diagnosis (PID) are considered here as interacting components of a complex adaptive system comprised of health status (functioning/wellness versus disability/disorder), experience of health (self-awareness/fulfillment versus misunderstanding/suffering) and contributors to health (protective versus risk factors). The PID domains thereby allow healthcare and health promotion to be understood in terms of measurable components of a complex adaptive system. Three major concepts of health are examined in detail to identify their dynamic origins: Psychological Maturity, Flourishing and Resilience. In humanistic psychology, psychological maturity (i.e. healthy personality, mental wellbeing) involves the development of high self-directedness, high co-operativeness and high self-transcendence, but self-transcendence is nevertheless devalued in individualistic and materialistic cultures except when people must face adversity and ultimate situations like suffering or the threat of death. Psychological Maturity develops through two complementary processes often labeled as Flourishing and Resilience. Flourishing is the development of one’s potential to live optimally, especially as the result of favorable circumstances, whereas Resilience is positive adaptation to life despite adverse circumstances. As a result of the complex feedback dynamics between the processes of flourishing and resilience, each person is a unique individual who has a variety of paths for achieving positive health and wellbeing open to

  16. Structural Dynamics Model Updating with Positive Definiteness and No Spillover

    Directory of Open Access Journals (Sweden)

    Yongxin Yuan

    2014-01-01

    Full Text Available Model updating is a common method to improve the correlation between structural dynamics models and measured data. In conducting the updating, it is desirable to match only the measured spectral data without tampering with the other unmeasured and unknown eigeninformation in the original model (if so, the model is said to be updated with no spillover and to maintain the positive definiteness of the coefficient matrices. In this paper, an efficient numerical method for updating mass and stiffness matrices simultaneously is presented. The method first updates the modal frequencies. Then, a method is presented to construct a transformation matrix and this matrix is used to correct the analytical eigenvectors so that the updated model is compatible with the measurement of the eigenvectors. The method can preserve both no spillover and the symmetric positive definiteness of the mass and stiffness matrices. The method is computationally efficient as neither iteration nor numerical optimization is required. The numerical example shows that the presented method is quite accurate and efficient.

  17. The positive group affect spiral : a dynamic model of the emergence of positive affective similarity in work groups

    NARCIS (Netherlands)

    Walter, F.; Bruch, H.

    2008-01-01

    This conceptual paper seeks to clarify the process of the emergence of positive collective affect. Specifically, it develops a dynamic model of the emergence of positive affective similarity in work groups. It is suggested that positive group affective similarity and within-group relationship qualit

  18. The positive group affect spiral : a dynamic model of the emergence of positive affective similarity in work groups

    NARCIS (Netherlands)

    Walter, F.; Bruch, H.

    This conceptual paper seeks to clarify the process of the emergence of positive collective affect. Specifically, it develops a dynamic model of the emergence of positive affective similarity in work groups. It is suggested that positive group affective similarity and within-group relationship

  19. Molecular dynamics study of nanojoining between axially positioned Ag nanowires

    Science.gov (United States)

    Cui, Jianlei; Theogene, Barayavuga; Wang, Xuewen; Mei, Xuesong; Wang, Wenjun; Wang, Kedian

    2016-08-01

    The miniaturization of electronics devices into nanometer scale is indispensable for next-generation semiconductor technology. Ag nanowires (Ag NWs) are considered to be the promising candidates for future electronic circuit owing to the excellent electrical and thermal properties. The nanojoining of axially positioned Ag NWs was performed by molecular dynamics simulation. Through the detailed atomic evolution during the nanojoining, the results indicate that the temperature and the distance between Ag NWs in axial direction have a great impact on nanojoining effect. When the nanojoining temperature is relatively high, the atoms are disordered and the atomic queues become to distort with strong thermodynamic properties and weak effect of metal bonds. At the relatively low temperature, the Ag NWs can be well connected with good junction quality and their own morphology, which is similar to the cold welding without fusion, while the distance between Ag NWs should be controlled for interaction and diffusion of interfacial atoms at nanowires head. When the Ag NWs are placed on Si and SiO2 substrate, because the atomic species and lattice structure of substrate material can differently affect the motions of Ag atoms through the interactive force between the atoms, the nanojoining quality of Ag NWs on Si substrate is better than that on the SiO2 substrate. So, for getting effective and reliable nanojoining without nanosolders and other materials, the temperature, distance and substrate surface should be reasonably controlled and selected, providing helpful theoretical guidance for experiment and application of nanojoining.

  20. Fluid Dynamics Appearing during Simulated Microgravity Using Random Positioning Machines

    Science.gov (United States)

    Stern, Philip; Casartelli, Ernesto; Egli, Marcel

    2017-01-01

    Random Positioning Machines (RPMs) are widely used as tools to simulate microgravity on ground. They consist of two gimbal mounted frames, which constantly rotate biological samples around two perpendicular axes and thus distribute the Earth’s gravity vector in all directions over time. In recent years, the RPM is increasingly becoming appreciated as a laboratory instrument also in non-space-related research. For instance, it can be applied for the formation of scaffold-free spheroid cell clusters. The kinematic rotation of the RPM, however, does not only distribute the gravity vector in such a way that it averages to zero, but it also introduces local forces to the cell culture. These forces can be described by rigid body analysis. Although RPMs are commonly used in laboratories, the fluid motion in the cell culture flasks on the RPM and the possible effects of such on cells have not been examined until today; thus, such aspects have been widely neglected. In this study, we used a numerical approach to describe the fluid dynamic characteristic occurring inside a cell culture flask turning on an operating RPM. The simulations showed that the fluid motion within the cell culture flask never reached a steady state or neared a steady state condition. The fluid velocity depends on the rotational velocity of the RPM and is in the order of a few centimeters per second. The highest shear stresses are found along the flask walls; depending of the rotational velocity, they can reach up to a few 100 mPa. The shear stresses in the “bulk volume,” however, are always smaller, and their magnitude is in the order of 10 mPa. In conclusion, RPMs are highly appreciated as reliable tools in microgravity research. They have even started to become useful instruments in new research fields of mechanobiology. Depending on the experiment, the fluid dynamic on the RPM cannot be neglected and needs to be taken into consideration. The results presented in this study elucidate the fluid

  1. Fluid Dynamics Appearing during Simulated Microgravity Using Random Positioning Machines.

    Science.gov (United States)

    Wuest, Simon L; Stern, Philip; Casartelli, Ernesto; Egli, Marcel

    2017-01-01

    Random Positioning Machines (RPMs) are widely used as tools to simulate microgravity on ground. They consist of two gimbal mounted frames, which constantly rotate biological samples around two perpendicular axes and thus distribute the Earth's gravity vector in all directions over time. In recent years, the RPM is increasingly becoming appreciated as a laboratory instrument also in non-space-related research. For instance, it can be applied for the formation of scaffold-free spheroid cell clusters. The kinematic rotation of the RPM, however, does not only distribute the gravity vector in such a way that it averages to zero, but it also introduces local forces to the cell culture. These forces can be described by rigid body analysis. Although RPMs are commonly used in laboratories, the fluid motion in the cell culture flasks on the RPM and the possible effects of such on cells have not been examined until today; thus, such aspects have been widely neglected. In this study, we used a numerical approach to describe the fluid dynamic characteristic occurring inside a cell culture flask turning on an operating RPM. The simulations showed that the fluid motion within the cell culture flask never reached a steady state or neared a steady state condition. The fluid velocity depends on the rotational velocity of the RPM and is in the order of a few centimeters per second. The highest shear stresses are found along the flask walls; depending of the rotational velocity, they can reach up to a few 100 mPa. The shear stresses in the "bulk volume," however, are always smaller, and their magnitude is in the order of 10 mPa. In conclusion, RPMs are highly appreciated as reliable tools in microgravity research. They have even started to become useful instruments in new research fields of mechanobiology. Depending on the experiment, the fluid dynamic on the RPM cannot be neglected and needs to be taken into consideration. The results presented in this study elucidate the fluid

  2. Completely positive dynamical semigroups and quantum resonance theory

    Science.gov (United States)

    Könenberg, Martin; Merkli, Marco

    2017-07-01

    Starting from a microscopic system-environment model, we construct a quantum dynamical semigroup for the reduced evolution of the open system. The difference between the true system dynamics and its approximation by the semigroup has the following two properties: It is (linearly) small in the system-environment coupling constant for all times, and it vanishes exponentially quickly in the large time limit. Our approach is based on the quantum dynamical resonance theory.

  3. Colpocystoproctography in the upright and supine positions correlated with dynamic MRI of the pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Gufler, Hubert E-mail: hubert.gufler@radiol.med.uni-giessen.de; Ohde, Angelika; Grau, Gabriele; Grossmann, Anette

    2004-07-01

    Purpose: To test whether there are statistically significant differences between measurement results on colpocystoproctography in the upright and the supine positions, and to correlate these results with dynamic MRI. Patients and Methods: Seven patients with pelvic floor descent had received colpocystoproctography in the upright and supine positions and, additionally, dynamic MRI of the pelvic floor. Bladder neck position, angle of urethral inclination, posterior vesicourethral angle, and vaginal vault position were measured at relaxed pelvic floor and at pelvic strain. Differences between the measurement results of each parameter in the upright and supine position on colpocystoproctography were calculated and correlated with the measurement results from the dynamic MRI. Results: At pelvic strain, bladder neck position, angle of urethral inclination, posterior vesicourethral angle and vaginal vault position measurements showed no statistically significant differences between colpocystoproctography in the upright and supine positions or dynamic MRI. For the bladder neck height at pelvic floor relaxation, significant differences were found between colpocystoproctography in the upright and supine positions, and colpocystoproctography in the upright position versus dynamic MRI. Conclusion: At pelvic strain, measurement data from dynamic MRI are not statistically different from data from colpocystoproctography either in supine and upright positions.

  4. Forced dynamic position control of PMSM with DTC utilization

    Science.gov (United States)

    Malek, Michal

    2012-11-01

    Almost one and a half century after the publication of Maxwell’s On Governors, feedback theory with PID controllers in cascade structure is still an essential part of control structures of most controlled electric drives. There are a few control strategies which are “ready” to replace it but they usually miss one of the essential fundamentals of every successful approach - simplicity hand in hand with lucidity. But there is one close relative which is simple and powerful at the same time, is not excessively abstract and without complicated mathematics. The name of this technique is Forced Dynamic Control. In this paper forced dynamic control is presented together with direct torque controlled PMSM drive as unique combination of simple algorithms for inner and outer loop of cascade structure.

  5. A Numerical Study on Hydrodynamic Interactions between Dynamic Positioning Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Doo Hwa; Lee, Sang Wook [University of Ulsan, Ulsan (Korea, Republic of)

    2017-06-15

    In this study, we conducted computational fluid dynamics (CFD) simulations for the unsteady hydrodynamic interaction of multiple thrusters by solving Reynolds averaged Navier-Stokes equations. A commercial CFD software, STAR-CCM+ was used for all simulations by employing a ducted thruster model with combination of a propeller and No. 19a duct. A sliding mesh technique was used to treat dynamic motion of propeller rotation and non-conformal hexahedral grid system was considered. Four different combinations in tilting and azimuth angles of the thrusters were considered to investigate the effects on the propulsion performance. We could find that thruster-hull and thruster-thruster interactions has significant effect on propulsion performance and further study will be required for the optimal configurations with the best tilting and relative azimuth angle between thrusters.

  6. Dynamics of relative chromosome position during the cell cycle.

    NARCIS (Netherlands)

    J. Essers (Jeroen); W.A. van Cappellen (Gert); A.F. Theil (Arjan); E. van Drunen (Ellen); N.G.J. Jaspers (Nicolaas); J.H.J. Hoeijmakers (Jan); C. Wyman (Claire); W. Vermeulen (Wim); R. Kanaar (Roland)

    2005-01-01

    textabstractThe position of chromosomal neighborhoods in living cells was followed using three different methods for marking chromosomal domains occupying arbitrary locations in the nucleus; photobleaching of GFP-labeled histone H2B, local UV-marked DNA, and photobleaching of fluorescently labeled

  7. Computational fluid dynamics vs. inverse dynamics methods to determine passive drag in two breaststroke glide positions.

    Science.gov (United States)

    Costa, L; Mantha, V R; Silva, A J; Fernandes, R J; Marinho, D A; Vilas-Boas, J P; Machado, L; Rouboa, A

    2015-07-16

    Computational fluid dynamics (CFD) plays an important role to quantify, understand and "observe" the water movements around the human body and its effects on drag (D). We aimed to investigate the flow effects around the swimmer and to compare the drag and drag coefficient (CD) values obtained from experiments (using cable velocimetry in a swimming pool) with those of CFD simulations for the two ventral gliding positions assumed during the breaststroke underwater cycle (with shoulders flexed and upper limbs extended above the head-GP1; with shoulders in neutral position and upper limbs extended along the trunk-GP2). Six well-trained breaststroke male swimmers (with reasonable homogeneity of body characteristics) participated in the experimental tests; afterwards a 3D swimmer model was created to fit within the limits of the sample body size profile. The standard k-ε turbulent model was used to simulate the fluid flow around the swimmer model. Velocity ranged from 1.30 to 1.70 m/s for GP1 and 1.10 to 1.50 m/s for GP2. Values found for GP1 and GP2 were lower for CFD than experimental ones. Nevertheless, both CFD and experimental drag/drag coefficient values displayed a tendency to jointly increase/decrease with velocity, except for GP2 CD where CFD and experimental values display opposite tendencies. Results suggest that CFD values obtained by single model approaches should be considered with caution due to small body shape and dimension differences to real swimmers. For better accuracy of CFD studies, realistic individual 3D models of swimmers are required, and specific kinematics respected.

  8. NONLINEAR FILTER METHOD OF GPS DYNAMIC POSITIONING BASED ON BANCROFT ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    ZHANGQin; TAOBen-zao; ZHAOChao-ying; WANGLi

    2005-01-01

    Because of the ignored items after linearization, the extended Kalman filter (EKF) becomes a form of suboptimal gradient descent algorithm. The emanative tendency exists in GPS solution when the filter equations are ill-posed. The deviation in the estimation cannot be avoided. Furthermore, the true solution may be lost in pseudorange positioning because the linearized pseudorange equations are partial solutions. To solve the above problems in GPS dynamic positioning by using EKF, a closed-form Kalman filter method called the two-stage algorithm is presented for the nonlinear algebraic solution of GPS dynamic positioning based on the global nonlinear least squares closed algorithm--Bancroft numerical algorithm of American. The method separates the spatial parts from temporal parts during processing the GPS filter problems, and solves the nonlinear GPS dynamic positioning, thus getting stable and reliable dynamic positioning solutions.

  9. Open system quantum dynamics with correlated initial states, not completely positive maps and non-Markovianity

    CERN Document Server

    Devi, A R Usha; Sudha,

    2010-01-01

    Dynamical A and B maps have been employed extensively by Sudarshan and co-workers to investigate open system evolution of quantum systems. A canonical structure of the A-map is introduced here. It is shown that this canonical A-map enables us to investigate if the dynamics is completely positive (CP) or non-completely positive (NCP) in an elegant way and hence, it subsumes the basic results on open system dynamics. Identifying memory effects in open system evolution is gaining increasing importance recently and here, a criterion of non-Markovianity, based on the relative entropy of the dynamical state is proposed. The relative entropy difference of the dynamical system serves as a complementary characterization - though not related directly - to the fidelity difference criterion proposed recently. Three typical examples of open system evolution of a qubit, prepared initially in a correlated state with another qubit (environment), and evolving jointly under a specific unitary dynamics - which corresponds to a ...

  10. Dynamic berth and quay crane allocation for multiple berth positions and quay cranes

    NARCIS (Netherlands)

    Tri Cahyono, Rully; Flonk, E.J.; Jayawardhana, Bayu

    2015-01-01

    We study in this paper a dynamic berth and quay cranes allocation strategy in general seaport container terminals. We develop a dynamical model that describes the operation of berthing process with multiple discrete berthing positions and multiple quay cranes. Based on the proposed model, we develop

  11. Kinematic and Dynamic Analysis of New Polar Positioning System Dedicated to Mechatronic Laser Glass Engraving System

    Directory of Open Access Journals (Sweden)

    Trochimczuk R.

    2014-11-01

    Full Text Available Analytical formulas describing the kinematics and dynamics of a multibody system of a new polar positioning system dedicated to mechatronic laser glass or other transparent dielectrics engraving system will be presented in this work. The analytical results will become in the later stages of the research the basis of numerical simulations. They will optimize the proposed solution of the positioning system.

  12. Upper Limb Asymmetries in the Perception of Proprioceptively Determined Dynamic Position Sense

    Science.gov (United States)

    Goble, Daniel J.; Brown, Susan H.

    2010-01-01

    Recent studies of position-related proprioceptive sense have provided evidence of a nonpreferred left arm advantage in right-handed individuals. The present study sought to determine whether similar asymmetries might exist in "dynamic position" sense. Thirteen healthy, right-handed adults were blindfolded and seated with arms placed on…

  13. Design and Reliability Analysis of DP-3 Dynamic Positioning Control Architecture

    Institute of Scientific and Technical Information of China (English)

    WANG Fang; WAN Lei; JIANG Da-peng; XU Yu-ru

    2011-01-01

    As the exploration and exploitation of oil and gas proliferate throughout deepwater area,the requirements on the reliability of dynamic positioning system become increasingly stringent.The control objective ensuring safety operation at deep water will not be met by a single controller for dynamic positioning.In order to increase the availability and reliability of dynamic positioning control system,the triple redundancy hardware and software control architectures were designed and developed according to the safe specifications of DP-3 classification notation for dynamically positioned ships and rigs.The hardware redundant configuration takes the form of triple-redundant hot standby configuration including three identical operator stations and three real-time control computers which connect each other through dual networks.The function of motion control and redundancy management of control computers were implemented by software on the real-time operating system VxWorks.The software realization of task loose synchronization,majority voting and fault detection were presented in details.A hierarchical software architecture was planed during the development of software,consisting of application layer,real-time layer and physical layer.The behavior of the DP-3 dynamic positioning control system was modeled by a Markov model to analyze its reliability.The effects of variation in parameters on the reliability measures were investigated.The time domain dynamic simulation was carried out on a deepwater drilling rig to prove the feasibility of the proposed control architecture.

  14. Dynamic tracking performance of indoor global positioning system: An experimental and theoretical study

    Directory of Open Access Journals (Sweden)

    Gang Zhao

    2015-10-01

    Full Text Available The automation level has been improved rapidly with the introduction of large-scale measurement technologies, such as indoor global positioning system, into the production process among the fields of car, ship, and aerospace due to their excellent measurement characteristics. In fact, the objects are usually in motion during the real measurement process; however, the dynamic measurement characteristics of indoor global positioning system are much limited and still in exploration. In this research, we focused on the dynamic tracking performance of indoor global positioning system and then successfully built a mathematical model based on its measurement principles. We first built single and double station system models with the consideration of measurement objects’ movement. Using MATLAB simulation, we realized the dynamic measurement characteristics of indoor global positioning system. In the real measurement process, the experimental results also support the mathematical model that we built, which proves a great success in dynamic measurement characteristics. We envision that this dynamic tracking performance of indoor global positioning system would shed light on the dynamic measurement of a motion object and therefore make contribution to the automation production.

  15. Z curve theory-based analysis of the dynamic nature of nucleosome positioning in Saccharomyces cerevisiae.

    Science.gov (United States)

    Wu, Xueting; Liu, Hui; Liu, Hongbo; Su, Jianzhong; Lv, Jie; Cui, Ying; Wang, Fang; Zhang, Yan

    2013-11-01

    Nucleosome is the elementary structural unit of eukaryotic chromatin. Instability of nucleosome positioning plays critical roles in chromatin remodeling in differentiation and disease. In this study, we investigated nucleosome dynamics in the Saccharomyces cerevisiae genome using a geometric model based on Z curve theory. We identified 52,941 stable nucleosomes and 7607 dynamic nucleosomes, compiling them into a genome-wide nucleosome dynamic positioning map and constructing a user-friendly visualization platform (http://bioinfo.hrbmu.edu.cn/nucleosome). Our approach achieved a sensitivity of 90.31% and a specificity of 87.76% for S. cerevisiae. Analysis revealed transcription factor binding sites (TFBSs) were enriched in linkers. And among the sparse nucleosomes around TFBSs, dynamic nucleosomes were slightly preferred. Gene Ontology (GO) enrichment analysis indicated that stable and dynamic nucleosomes were enriched on genes involved in different biological processes and functions. This study provides an approach for comprehending chromatin remodeling and transcriptional regulation of genes.

  16. A UWB/Improved PDR Integration Algorithm Applied to Dynamic Indoor Positioning for Pedestrians.

    Science.gov (United States)

    Chen, Pengzhan; Kuang, Ye; Chen, Xiaoyue

    2017-09-08

    Inertial sensors are widely used in various applications, such as human motion monitoring and pedestrian positioning. However, inertial sensors cannot accurately define the process of human movement, a limitation that causes data drift in the process of human body positioning, thus seriously affecting positioning accuracy and stability. The traditional pedestrian dead-reckoning algorithm, which is based on a single inertial measurement unit, can suppress the data drift, but fails to accurately calculate the number of walking steps and heading value, thus it cannot meet the application requirements. This study proposes an indoor dynamic positioning method with an error self-correcting function based on the symmetrical characteristics of human motion to obtain the definition basis of human motion process quickly and to solve the abovementioned problems. On the basis of this proposed method, an ultra-wide band (UWB) method is introduced. An unscented Kalman filter is applied to fuse inertial sensors and UWB data, inertial positioning is applied to compensation for the defects of susceptibility to UWB signal obstacles, and UWB positioning is used to overcome the error accumulation of inertial positioning. The above method can improve both the positioning accuracy and the response of the positioning results. Finally, this study designs an indoor positioning test system to test the static and dynamic performances of the proposed indoor positioning method. Results show that the positioning system both has high accuracy and good real-time performance.

  17. Adaptive Indoor Positioning Model Based on WLAN-Fingerprinting for Dynamic and Multi-Floor Environments

    Directory of Open Access Journals (Sweden)

    Iyad Husni Alshami

    2017-08-01

    Full Text Available The Global Positioning System demonstrates the significance of Location Based Services but it cannot be used indoors due to the lack of line of sight between satellites and receivers. Indoor Positioning Systems are needed to provide indoor Location Based Services. Wireless LAN fingerprints are one of the best choices for Indoor Positioning Systems because of their low cost, and high accuracy, however they have many drawbacks: creating radio maps is time consuming, the radio maps will become outdated with any environmental change, different mobile devices read the received signal strength (RSS differently, and peoples’ presence in LOS between access points and mobile device affects the RSS. This research proposes a new Adaptive Indoor Positioning System model (called DIPS based on: a dynamic radio map generator, RSS certainty technique and peoples’ presence effect integration for dynamic and multi-floor environments. Dynamic in our context refers to the effects of people and device heterogeneity. DIPS can achieve 98% and 92% positioning accuracy for floor and room positioning, and it achieves 1.2 m for point positioning error. RSS certainty enhanced the positioning accuracy for floor and room for different mobile devices by 11% and 9%. Then by considering the peoples’ presence effect, the error is reduced by 0.2 m. In comparison with other works, DIPS achieves better positioning without extra devices.

  18. Modeling and Control for Dynamic Positioned Marine Vessels in Drifting Managed Sea Ice

    Directory of Open Access Journals (Sweden)

    Øyvind Kåre Kjerstad

    2014-10-01

    Full Text Available This paper presents a development framework for dynamic positioning control systems for marine vessels in managed ice. Due to the complexity of the vessel-ice and ice-ice interactions a configurable high fidelity numerical model simulating the vessel, the ice floes, the water, and the boundaries is applied. The numerical model is validated using experimental data and coupled with a control application incorporating sensor models, control systems, actuator models, and other external dynamics to form a closed loop development platform. The ice drift reversal is simulated by moving the positioning reference frame in an elliptic trajectory, rather than moving each individual ice floe. A control plant model is argued, and a control system for managed ice is proposed based on conventional open water design methods. A case study shows that dynamic positioning in managed ice is feasible for some moderate ice conditions.

  19. Position Control of Linear Synchronous Motor Drives with Exploitation of Forced Dynamics Control Principles

    Directory of Open Access Journals (Sweden)

    Jan Vittek

    2004-01-01

    Full Text Available Closed-loop position control of mechanisms directly driven by linear synchronous motors with permanent magnets is presented. The control strategy is based on forced dynamic control, which is a form of feedback linearisation, yielding a non-liner multivariable control law to obtain a prescribed linear speed dynamics together with the vector control condition of mutal orthogonality between the stator current and magnetic flux vectors (assuming perfect estimates of the plant parameters. Outer position control loop is closed via simple feedback with proportional gain. Simulations of the design control sysstem, including the drive with power electronic switching, predict the intended drive performance.

  20. Trajectories of experience of real life events. A semiotic approach to the dynamics of positioning.

    Science.gov (United States)

    Rosa, Alberto; González, Fernanda

    2013-12-01

    This paper is devoted to the study of experience as a semiotic process of constructing the personal meaning of the situation lived. Its main purpose is to devise a semiotic methodology capable of describing and explaining the dynamics of positioning when facing personal lived experiences in real life contexts. Twenty four young adults were exposed to a simulated conflict and then asked to write a narrative of their understanding of the incident and a self-report of their personal experiences. Results show how narratives and trajectories of experience present different forms in each participant, which could be related to: a) the understanding of the situation lived and the position taken regarding the conflict; and b) the position each participant takes regarding the reports they had to produce for the researchers. The incorporation of reflexivity into the applied method allows identification of how the dynamics of double positioning leave traces in the records produced.

  1. Dynamic Effects of Anchor Positional Tolerance on Tension Moored Floating Wind Turbine

    Science.gov (United States)

    Wright, Christopher; Pakrashi, Vikram; Murphy, Jimmy

    2016-09-01

    For water depths greater than 60m floating wind turbines will become the most economical option for generating offshore wind energy. Tension mooring stabilised units are one type of platform being considered by the offshore wind energy industry. The complex mooring arrangement used by this type of platform means that the dynamics are greatly effected by offsets in the positioning of the anchors. This paper examines the issue of tendon anchor position tolerances. The dynamic effects of three positional tolerances are analysed in survival state using the time domain FASTLink. The severe impact of worst case anchor positional offsets on platform and turbine survivability is shown. The worst anchor misposition combinations are highlighted and should be strongly avoided. Novel methods to mitigate this issue are presented.

  2. A dynamic compensation strategy to correct patient-positioning errors in conformal prostate radiotherapy.

    Science.gov (United States)

    Lauve, A D; Siebers, J V; Crimaldi, A J; Hagan, M P; Kealla, P J

    2006-06-01

    Traditionally, pretreatment detected patient-positioning errors have been corrected by repositioning the couch to align the patient to the treatment beam. We investigated an alternative strategy: aligning the beam to the patient by repositioning the dynamic multileaf collimator and adjusting the beam weights, termed dynamic compensation. The purpose of this study was to determine the geometric range of positioning errors for which the dynamic compensation method is valid in prostate cancer patients treated with three-dimensional conformal radiotherapy. Twenty-five previously treated prostate cancer patients were replanned using a four-field technique to deliver 72 Gy to 95% of the planning target volume (PTV). Patient-positioning errors were introduced by shifting the patient reference frame with respect to the treatment isocenter. Thirty-six randomly selected isotropic displacements with magnitudes of 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 cm were sampled for each patient, for a total of 5400 errors. Dynamic compensation was used to correct each of these errors by conforming the beam apertures to the new target position and adjusting the monitor units using inverse-square and off-axis factor corrections. The dynamic compensation plans were then compared with the original treatment plans via dose-volume histogram (DVH) analysis. Changes of more than 5% of the prescription dose, 3.6 Gy, were deemed significant. Compared with the original treatment plans, dynamic compensation produced small discrepancies in isodose distributions and DVH analyses. These differences increased with the magnitudes of the initial patient-positioning errors. Coverage of the PTV was excellent: D95 and Dmean were not increased or decreased by more than 5% of the prescription dose, and D5 was not decreased by more than 5% of the prescription dose for any of the 5400 simulated positioning errors. D5 was increased by more than 5% of the prescription dose in only three of the 5400 positioning errors

  3. The temporal dynamics of detached versus positive reappraisal: An ERP study.

    Science.gov (United States)

    Qi, Senqing; Li, Yangping; Tang, Xuemei; Zeng, Qinghong; Diao, Liuting; Li, Xiying; Li, Hong; Hu, Weiping

    2017-01-23

    Detached reappraisal and positive reappraisal are regarded as two distinct types of cognitive reappraisal strategy, and the former is considered more disengaging than the latter. The conceptual framework of emotion regulation choice posits that strategies involving disengagement operate earlier and more efficiently than engagement strategies. Here, we compare for the first time the temporal dynamics of detached and positive reappraisal during the regulation and re-exposure phases thereof by measuring event-related potentials. During the regulation phase, pictures were viewed or regulated using detached or positive reappraisal. During the re-exposure phase, the same pictures were viewed again. Results showed that during regulation, central-parietal late positive potentials (LPPs) were greatly attenuated under both strategy types, with the regulation effect of detached reappraisal occurring earlier than that of positive reappraisal and resulting in a stronger attenuation of LPP amplitudes. Upon re-exposure, detached reappraisal exerted enduring effects on self-reported arousal and the central-parietal LPP, whereas positive reappraisal had an enduring effect only on pleasantness. These findings demonstrate the differential effects of detached and positive reappraisal on valence, arousal, and neural responses, and underline the striking differences in the temporal dynamics of these reappraisal strategies.

  4. POSITIVE SOLUTIONS FOR p-LAPLACIAN DYNAMIC EQUATIONS ON TIME SCALES

    Institute of Scientific and Technical Information of China (English)

    Geng Fengjie; Zhu Deming; Li Hongzhi

    2007-01-01

    The three-point boundary value problems of p-Laplacian dynamic equations on time scales are investigated. By using Krasnosel'skii's fixed-point theorem and fixed-point index theorem, criteria are achieved for the existence of at least one, two or 2n positive solutions.Furthermore, some examples are included to illustrate the main theorems.

  5. Dynamics of Positive Interactions between General Education Students and Students with Special Needs: A Phenomenological Study

    Science.gov (United States)

    Rider, Brian J.

    2013-01-01

    This dissertation examined the dynamics of positive interactions between general education students and students with special needs in elementary inclusion-based physical education settings. More specifically, this qualitative study used a phenomenological research methodology aimed to examine the multiple factors contributing to general education…

  6. Nonlinear dynamic positioning of ships with gain-scheduled wave filtering

    DEFF Research Database (Denmark)

    Torsetnes, Guttorm; Jouffroy, Jerome; Fossen, Thor I.

    This paper presents a globally contracting controller for regulation and dynamic positioning of ships, using only position measurements. For this purpose a globally contracting observer which reconstructs the unmeasured states is constructed. The observer produces accurate estimates of position......, slowly varying environmental disturbances (bias terms) and velocity. The estimates are automatically adjusted to the present sea state by gain-scheduling the wave model parameters in the observer. Finally, the estimates are used in a nonlinear PID control law and the stability proof of the observer...

  7. [Mes differ by positioning: empirical testing of decentralized dynamics of the self].

    Science.gov (United States)

    Mizokami, Shinichi

    2013-10-01

    The present study empirically tested the conceptualization of the decentralized dynamics of the self proposed by Hermans & Kempen (1993), which they developed theoretically and from clinical cases, not from large samples of empirical data. They posited that worldviews and images of the self could vary by positioning even in the same individual, and denied that the ego was an omniscient entity that knew and controlled all aspects of the self (centralized ego). Study 1 tested their conceptualization empirically with 47 university students in an experimental group and 17 as a control group. The results showed that the scores on the Rosenberg's self-esteem scale and images of the Mes in the experimental group significantly varied by positioning, but those in the control group did not. Similar results were found in Study 2 with a sample of 120 university students. These results empirically supported the conceptualization of the decentralized dynamics of the self.

  8. A D-optimal Multi-position Calibration Method for Dynamically Tuned Gyroscopes

    Institute of Scientific and Technical Information of China (English)

    FU Li; ZHU Yongquan; WANG Lingling; WANG Xinling

    2011-01-01

    This paper presents a novel experimental design to greatly improve the calibration accuracy of the acceleration-insensitive bias and the acceleration-sensitive bias of the dynamically tuned gyroscopes (DTGs). In order to reduce experimental cost, the D-optimal criteria with constraints are constructed. The turntable positions and the number of test points are chosen to build D-optimal experimental designs. The D-optimal experimental designs are tested by multi-position calibration experiment for tactical-grade DTGs. Test results show that, with the same cost, the fit uncertainty is reduced by about 50% by using the D-optimal 8-position experimental procedure, compared to using a defacto standard experimental procedure in ANSI/IEEE Std 813-1988. Furthermore, the new experimental procedure almost achieves optimal accuracy with only 12-position which is half the cost of the widely adopted 24-position experimental procedure for achieving optimal accuracy.

  9. Dynamic positioning system of ship%船舶动力定位系统

    Institute of Scientific and Technical Information of China (English)

    郑荣才; 宋健力; 黎琼; 吴园园; 窦玉宝

    2013-01-01

    With the developments of deep-sea technologies, the dynamic positioning system(DPS) has been widely applied in offshore project. The dynamically positioned system of a vessel is designed to accurately maintain the vessel’s position and heading at a fixed location or a predetermined track for marine operation purposes by exclusively using active thrusters. In this paper, the development and application of the dynamic positioning(DP) system were investigated. The principle how the DP works was analyzed. The typical configurations of the foreign famous DPS were studied. The system restrictions, control strategy, control technology,and thrust allocation of DP were analyzed. It was pointed that the accuracy of dynamic positioning system depends on dynamic positioning control and measurement equipment. Based on the researches above, an approach to develop our own dynamic positioning system was presented.%随着深海技术的不断发展,动力定位系统的在海洋工程上得到广泛应用。动力定位系统通过其控制系统驱动船舶推进器来抵消风、浪、流等作用于船上的环境外力,从而使船舶保持在确定的位置上或沿预期的航迹航行。本文在分析了国际海事组织和国际海洋工程承包商协会对动力定位系统定义及分级要求的基础上,阐述了国外船舶动力定位系统的发展及其应用状况,分析了动力定位系统的组成和工作原理,研究了动力定位系统的各种约束、控制策略、控制技术、推力分配等关键技术,指出动力定位系统精度取决于控制系统和测量系统性能,并提出了发展国产动力定位系统应采用的途径。

  10. Software development for dynamic position emission tomography: Dynamic image analysis (DIA) tool

    Energy Technology Data Exchange (ETDEWEB)

    Pyeon, Do Yeong; Jung, Young Jin [Dongseo University, Busan (Korea, Republic of); Kim, Jung Su [Dept. of Radilogical Science, Dongnam Health University, Suwon (Korea, Republic of)

    2016-09-15

    Positron Emission Tomography(PET) is nuclear medical tests which is a combination of several compounds with a radioactive isotope that can be injected into body to quantitatively measure the metabolic rate (in the body). Especially, Phenomena that increase (sing) glucose metabolism in cancer tissue using the 18F-FDG (Fluorodeoxyglucose) is utilized widely in cancer diagnosis. And then, Numerous studies have been reported that incidence seems high availability even in the modern diagnosis of dementia and Parkinson's (disease) in brain disease. When using a dynamic PET image including the time information in the static information that is provided for the diagnosis many can increase the accuracy of diagnosis. For this reason, clinical researchers getting great attention but, it is the lack of tools to conduct research. And, it interfered complex mathematical algorithm and programming skills for activation of research. In this study, in order to easy to use and enable research dPET, we developed the software based graphic user interface(GUI). In the future, by many clinical researcher using DIA-Tool is expected to be of great help to dPET research.

  11. Simulation of longitudinal dynamics of long freight trains in positioning operations

    Science.gov (United States)

    Qi, Zhaohui; Huang, Zhihao; Kong, Xianchao

    2012-09-01

    Positioning operations are performed in a railway goods yard, in which the freight train is pulled precisely at a specific point by a positioner. The positioner moves strictly according to the predesigned speed and provides all the traction and braking forces which are highly dependent on the longitudinal dynamic response. In order to improve the efficiency and protect the wagons from damage during positioning operations, the design speed of the positioner has to be optimised based on the simulation of longitudinal train dynamics. However, traditional models of longitudinal train dynamics are not accurate enough in some aspects. In this study, we make some changes in the traditional theory to make it suitable for the study of long freight trains in positioning operations. In the proposed method, instead of the traction force on the train, the motion of the positioner is assumed to be known; more importantly, the traditional draft gear model with nonlinear spring and linear damping is replaced by a more detailed model based on the achievement of contact and impact mechanics; the switching effects of the resistance and the coupler slack are also taken into consideration. Numerical examples that deal with positioning operations on the straight lines, slope lines and curving lines are given.

  12. Positive role of glassy dynamics in finite-time optimization by threshold algorithms

    Science.gov (United States)

    Hasegawa, M.

    2011-01-01

    The optimization mechanism of threshold algorithms is investigated in the solving process of a random Euclidean traveling salesman problem. A series of computer experiments previously designed for simulated annealing is conducted with algorithms such as generalized simulated annealing. The results show that if the threshold function decays fast enough, a previous positive view of slow relaxation dynamics in finite-time optimization by simulated annealing is still applicable regardless of the algorithm. These dynamics work effectively as an optimizer at around an intermediate temperature, which can be identified by using the Deborah number.

  13. Qualitative and quantitative analysis of stability and instability dynamics of positive lattice solitons.

    Science.gov (United States)

    Sivan, Y; Fibich, G; Ilan, B; Weinstein, M I

    2008-10-01

    We present a unified approach for qualitative and quantitative analysis of stability and instability dynamics of positive bright solitons in multidimensional focusing nonlinear media with a potential (lattice), which can be periodic, periodic with defects, quasiperiodic, single waveguide, etc. We show that when the soliton is unstable, the type of instability dynamic that develops depends on which of two stability conditions is violated. Specifically, violation of the slope condition leads to a focusing instability, whereas violation of the spectral condition leads to a drift instability. We also present a quantitative approach that allows one to predict the stability and instability strength.

  14. Position-dependent dynamics of a trapped ion in a standing wave laser

    Institute of Scientific and Technical Information of China (English)

    方卯发

    2002-01-01

    We have investigated the position-dependent dynamics of a trapped ion in a standing wave laser by transforming it to the Jaynes-Cummings-type system under the Lamb-Dicke limit. A variety of novel phenomena are exhibited,e.g. periodic collapse and revival features and long-time scaled revivals of the ionic inversion, depending on its position in the standing wave. Our result provides a way of producing a system equivalent to the two-photon Jaynes-Cummings model in the trapped ion system, with its exact periodicities.

  15. Dynamics and Feedback Control of Plasma Equilibrium Position in a Tokamak.

    Science.gov (United States)

    Burenko, Oleg

    A brief history of the beginnings of nuclear fusion research involving toroidal closed-system magnetic plasma containment is presented. A tokamak machine is defined mathematically for the purposes of plasma equilibrium position perturbation analysis. The perturbation equations of a tokamak plasma equilibrium position are developed. Solution of the approximated perturbation equations is carried out. A unique, simple, and useful plasma displacement dynamics transfer function of a tokamak is developed. The dominant time constants of the dynamics transfer function are determined in a symbolic form. This symbolic form of the dynamics transfer function makes it possible to study the stability of a tokamak's plasma equilibrium position. Knowledge of the dynamics transfer function permits systematic syntheses of the required plasma displacement feedback control systems. The major parameters governing the plasma equilibrium position stability of a tokamak are shown to be (1) external magnetic field decay index, (2) transformer iron core effect, (3) plasma current, (4) radial rate-of-change inductance parameter, (5) vertical rate-of-change inductance parameter, and (6) vacuum vessel eddy-current time constant. An important and unique result is derived, showing that for a vacuum vessel eddy-current time constant exceeding a certain value the vertical plasma equilibrium position is stable, in spite of an intentional vertical instability design represented by a negative decay index. It is shown that a tokamak design having a theoretical set of positive decay index, negative radical rate-of-change inductance parameter, and positive vertical rate-of-change inductance parameter is expected to have a better plasma equilibrium position stability tolerance than a tokamak design having the same set with the signs reversed. The results of an actual hardware ISX-A tokamak plasma displacement feed-back control system design are presented. It is shown that a theoretical design computer

  16. Aging and emotional expressions: is there a positivity bias during dynamic emotion recognition?

    Directory of Open Access Journals (Sweden)

    Alberto eDi Domenico

    2015-08-01

    Full Text Available In this study, we investigated whether age-related differences in emotion regulation priorities influence online dynamic emotional facial discrimination. A group of 40 younger and a group of 40 older adults were invited to recognize a positive or negative expression as soon as the expression slowly emerged and subsequently rate it in terms of intensity. Our findings show that older adults recognized happy expressions faster than angry ones, while the direction of emotional expression does not seem to affect younger adults’ performance. Furthermore, older adults rated both negative and positive emotional faces as more intense compared to younger controls. This study detects age-related differences with a dynamic online paradigm and suggests that different regulation strategies may shape emotional face recognition.

  17. Systems Theoretic Process Analysis Applied to an Offshore Supply Vessel Dynamic Positioning System

    Science.gov (United States)

    2016-06-01

    analysis of software and modern technologies into these traditional analysis methods; however, the underlying assumptions that make up the...automation that the DP system can operate with, the various sensors that allow for dynamic positioning to occur, and the signal processing unit within...sections. 1.3.1. Fault Tree Analysis According to the Reliability Design Handbook , Fault Tree Analysis (FTA) is a “procedure that can be

  18. A High Dynamic-Range Beam Position Measurement System for ELSA-2

    CERN Document Server

    Balleyguier, P; Guimbal, P; Borrion, H

    2003-01-01

    New beamlines are presently under construction for ELSA, a 20 MeV electron linac located at Bruyères-le-Châtel. These lines need a beam position measurement system filling the following requirements: small footprint, wide dynamic range, single-bunch/multi-bunch capability, simple design. We designed a compact 4-stripline sensor and an electronic treatment chain based on logarithmic amplifiers. This paper presents the design, cold and hot test results.

  19. Existence and Uniqueness of Positive and Bounded Solutions of a Discrete Population Model with Fractional Dynamics

    Directory of Open Access Journals (Sweden)

    J. E. Macías-Díaz

    2017-01-01

    Full Text Available We depart from the well-known one-dimensional Fisher’s equation from population dynamics and consider an extension of this model using Riesz fractional derivatives in space. Positive and bounded initial-boundary data are imposed on a closed and bounded domain, and a fully discrete form of this fractional initial-boundary-value problem is provided next using fractional centered differences. The fully discrete population model is implicit and linear, so a convenient vector representation is readily derived. Under suitable conditions, the matrix representing the implicit problem is an inverse-positive matrix. Using this fact, we establish that the discrete population model is capable of preserving the positivity and the boundedness of the discrete initial-boundary conditions. Moreover, the computational solubility of the discrete model is tackled in the closing remarks.

  20. Indoor Localisation Using a Context-Aware Dynamic Position Tracking Model

    Directory of Open Access Journals (Sweden)

    Montserrat Ros

    2012-01-01

    Full Text Available Indoor wireless localisation is a widely sought feature for use in logistics, health, and social networking applications. Low-powered localisation will become important for the next generation of pervasive media applications that operate on mobile platforms. We present an inexpensive and robust context-aware tracking system that can track the position of users in an indoor environment, using a wireless smart meter network. Our context-aware tracking system combines wireless trilateration with a dynamic position tracking model and a probability density map to estimate indoor positions. The localisation network consisted of power meter nodes placed at known positions in a building. The power meter nodes are tracked by mobile nodes which are carried by users to localise their position. We conducted an extensive trial of the context-aware tracking system and performed a comparison analysis with existing localisation techniques. The context-aware tracking system was able to localise a person's indoor position with an average error of 1.21 m.

  1. Dynamic WIFI-Based Indoor Positioning in 3D Virtual World

    Science.gov (United States)

    Chan, S.; Sohn, G.; Wang, L.; Lee, W.

    2013-11-01

    A web-based system based on the 3DTown project was proposed using Google Earth plug-in that brings information from indoor positioning devices and real-time sensors into an integrated 3D indoor and outdoor virtual world to visualize the dynamics of urban life within the 3D context of a city. We addressed limitation of the 3DTown project with particular emphasis on video surveillance camera used for indoor tracking purposes. The proposed solution was to utilize wireless local area network (WLAN) WiFi as a replacement technology for localizing objects of interest due to the wide spread availability and large coverage area of WiFi in indoor building spaces. Indoor positioning was performed using WiFi without modifying existing building infrastructure or introducing additional access points (AP)s. A hybrid probabilistic approach was used for indoor positioning based on previously recorded WiFi fingerprint database in the Petrie Science and Engineering building at York University. In addition, we have developed a 3D building modeling module that allows for efficient reconstruction of outdoor building models to be integrated with indoor building models; a sensor module for receiving, distributing, and visualizing real-time sensor data; and a web-based visualization module for users to explore the dynamic urban life in a virtual world. In order to solve the problems in the implementation of the proposed system, we introduce approaches for integration of indoor building models with indoor positioning data, as well as real-time sensor information and visualization on the web-based system. In this paper we report the preliminary results of our prototype system, demonstrating the system's capability for implementing a dynamic 3D indoor and outdoor virtual world that is composed of discrete modules connected through pre-determined communication protocols.

  2. Portraying Temporal Dynamics of Urban Spatial Divisions with Mobile Phone Positioning Data: A Complex Network Approach

    Directory of Open Access Journals (Sweden)

    Meng Zhou

    2016-12-01

    Full Text Available Spatial structure is a fundamental characteristic of cities that influences the urban functioning to a large extent. While administrative partitioning is generally done in the form of static spatial division, understanding a more temporally dynamic structure of the urban space would benefit urban planning and management immensely. This study makes use of a large-scale mobile phone positioning dataset to characterize the diurnal dynamics of the interaction-based urban spatial structure. To extract the temporally vibrant structure, spatial interaction networks at different times are constructed based on the movement connections of individuals between geographical units. Complex network community detection technique is applied to identify the spatial divisions as well as to quantify their temporal dynamics. Empirical analysis is conducted using data containing all user positions on a typical weekday in Shenzhen, China. Results are compared with official zoning and planned structure and indicate a certain degree of expansion in urban central areas and fragmentation in industrial suburban areas. A high level of variability in spatial divisions at different times of day is detected with some distinct temporal features. Peak and pre-/post-peak hours witness the most prominent fluctuation in spatial division indicating significant change in the characteristics of movements and activities during these periods of time. Findings of this study demonstrate great potential of large-scale mobility data in supporting intelligent spatial decision making and providing valuable knowledge to the urban planning sectors.

  3. Dynamic Infrared Thermography Study of Blood Flow Relative to Lower Limp Position

    Science.gov (United States)

    Stathopoulos, I.; Skouroliakou, K.; Michail, C.; Valais, I.

    2015-09-01

    Thermography is an established method for studying skin temperature distribution. Temperature distribution on body surface is influenced by a variety of physiological mechanisms and has been proven a reliable indicator of various physiological disorders. Blood flow is an important factor that influences body heat diffusion and skin temperature. In an attempt to validate and further elucidate thermal models characterizing the human skin, dynamic thermography of the lower limp in horizontal and vertical position was performed, using a FLIR T460 thermographic camera. Temporal variation of temperature was recorded on five distinct points of the limp. Specific points were initially cooled by the means of an ice cube and measurements of the skin temperature were obtained every 30 seconds as the skin temperature was locally reduced and afterwards restored at its initial value. The return to thermal balance followed roughly the same pattern for all points of measurement, although the heating rate was faster when the foot was in horizontal position. Thermal balance was achieved faster at the spots that were positioned on a vein passage. Our results confirm the influence of blood flow on the thermal regulation of the skin. Spots located over veins exhibit different thermal behaviour due to thermal convection through blood flow. Changing the position of the foot from vertical to horizontal, effectively affects blood perfusion as in the vertical position blood circulation is opposed by gravity.

  4. Existence of positive solutions for nonlinear dynamic systems with a parameter on a measure chain

    Directory of Open Access Journals (Sweden)

    Shuang-Hong Ma

    2007-05-01

    Full Text Available In this paper, we consider the following dynamic system with parameter on a measure chain $mathbb{T}$, $$displaylines{ u^{DeltaDelta}_{i}(t+lambda h_{i}(tf_{i}(u_{1}(sigma(t, u_{2}(sigma(t,dots ,u_{n}(sigma(t=0,quad tin[a,b], cr alpha u_{i}(a-eta u^{Delta}_{i}(a=0,quad gamma u_{i}(sigma(b+delta u^{Delta}_{i}(sigma(b=0, }$$ where $i=1,2,dots ,n$. Using fixed-point index theory, we find sufficient conditions the existence of positive solutions.

  5. Model Predictive Controller Design for the Dynamic Positioning System of a Semi-submersible Platform

    Institute of Scientific and Technical Information of China (English)

    Hongli Chen; Lei Wan; Fang Wang; Guocheng Zhang

    2012-01-01

    This paper researches how to apply the advanced control technology of model predictive control (MPC) to the design of the dynamic positioning system (DPS) of a semi-submersible platform.First,a linear low-frequency motion model with three degrees of freedom was established in the context of a semi-submersible platform.Second,a model predictive controller was designed based on a model which took the constraints of the system into account.Third,simulation was carried out to demonstrate the feasibility of the controller.The results show that the model predictive controller has good performance and good at dealing with the constraints of the system.

  6. Club position relative to the golfer's swing plane meaningfully affects swing dynamics.

    Science.gov (United States)

    MacKenzie, Sasho J

    2012-06-01

    Previous research indicates that the motion of the golf club is not planar and that the plane traced out by the club is different than that of the golfer's hands. The aim of the present study was to investigate how the position of the club, relative to the golfer's swing plane, influences the motion of the club by using a four-segment (torso, upper arm, forearm, and club), three-dimensional forward dynamics model. A genetic algorithm optimized the coordination of the model's four muscular torque generators to produce the best golf swings possible under six different conditions. The series of simulations were designed to demonstrate the effect of positioning the club above, and below, the golfer's swing plane as well as the effect of changing the steepness of the golfer's swing plane. The simulation results suggest that positioning the club below the golfer's swing plane, early in the downswing, will facilitate the squaring of the clubface for impact, while positioning the club above the plane will have the opposite effect. It was also demonstrated that changing the steepness of the golfer's swing plane by 10 degrees can have little effect on the delivery of the clubhead to the ball.

  7. Effect of dynamic temperature stimulus to plantar surface of the foot in the standing position

    Directory of Open Access Journals (Sweden)

    Ryo Watanabe

    2016-11-01

    Full Text Available We have previously found that a vertical force or tactile sensation occurs when the temperature of a participant's skin changes rapidly. In this illusion, upward motion, pressure or force sensation is elicited when stimulus temperature rises rapidly, whereas in the opposite case, downward motion or pulling sensation is elicited. In this paper, we applied this phenomenon to the sole (plantar surface of the foot to present the sensation of ground slope. To investigate this, we conducted an experiment that measured the correlation between stimulation temperature and front-back direction position of the center of gravity (COG. Participants stood on a thermal stimulator on Nintendo Wii Balance Board (WBB and they remained standing during 30 s dynamic temperature stimulus. In result of analysis, it was suggested that dynamic thermal change in sole might influence standing position and the effect pattern was anomalous in case of the participants who reported a swaying sensation without a haptic sensation. This behavior might be applied to the diagnosis of the presence of thermoesthesia of the patients who might have disease with absence of thermoesthesia.

  8. Positive feedback can lead to dynamic nanometer-scale clustering on cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wehrens, Martijn; Rein ten Wolde, Pieter [FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Mugler, Andrew, E-mail: amugler@purdue.edu [FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-11-28

    Clustering of molecules on biological membranes is a widely observed phenomenon. A key example is the clustering of the oncoprotein Ras, which is known to be important for signal transduction in mammalian cells. Yet, the mechanism by which Ras clusters form and are maintained remains unclear. Recently, it has been discovered that activated Ras promotes further Ras activation. Here we show using particle-based simulation that this positive feedback is sufficient to produce persistent clusters of active Ras molecules at the nanometer scale via a dynamic nucleation mechanism. Furthermore, we find that our cluster statistics are consistent with experimental observations of the Ras system. Interestingly, we show that our model does not support a Turing regime of macroscopic reaction-diffusion patterning, and therefore that the clustering we observe is a purely stochastic effect, arising from the coupling of positive feedback with the discrete nature of individual molecules. These results underscore the importance of stochastic and dynamic properties of reaction diffusion systems for biological behavior.

  9. Dynamic Positioning System (DPS) Risk Analysis Using Probabilistic Risk Assessment (PRA)

    Science.gov (United States)

    Thigpen, Eric B.; Boyer, Roger L.; Stewart, Michael A.; Fougere, Pete

    2017-01-01

    The National Aeronautics and Space Administration (NASA) Safety & Mission Assurance (S&MA) directorate at the Johnson Space Center (JSC) has applied its knowledge and experience with Probabilistic Risk Assessment (PRA) to projects in industries ranging from spacecraft to nuclear power plants. PRA is a comprehensive and structured process for analyzing risk in complex engineered systems and/or processes. The PRA process enables the user to identify potential risk contributors such as, hardware and software failure, human error, and external events. Recent developments in the oil and gas industry have presented opportunities for NASA to lend their PRA expertise to both ongoing and developmental projects within the industry. This paper provides an overview of the PRA process and demonstrates how this process was applied in estimating the probability that a Mobile Offshore Drilling Unit (MODU) operating in the Gulf of Mexico and equipped with a generically configured Dynamic Positioning System (DPS) loses location and needs to initiate an emergency disconnect. The PRA described in this paper is intended to be generic such that the vessel meets the general requirements of an International Maritime Organization (IMO) Maritime Safety Committee (MSC)/Circ. 645 Class 3 dynamically positioned vessel. The results of this analysis are not intended to be applied to any specific drilling vessel, although provisions were made to allow the analysis to be configured to a specific vessel if required.

  10. Positive circuits and maximal number of fixed points in discrete dynamical systems

    CERN Document Server

    Richard, Adrien

    2008-01-01

    The biologist Ren\\'e Thomas conjectured, twenty years ago, that the presence of a positive circuit in the interaction graph of a dynamical system is a necessary condition for the presence of multiple stable states. Recently, Richard and Comet stated and proved this conjecture for systems whose dynamics is described by the iterations of a map $F$ which operates on the product $X$ of $n$ finite intervals of integers. In this paper, we widely extend the result of Richard and Comet by exhibiting an upper bound on the number of fixed points for $F$ which only depends on $X$ and on the topology of the positive circuits of the interaction graph associated with $F$. Our motivation for this work comes from biology. The maps $F$ we focus on are indeed extensively used to described the behavior of gene regulatory networks, and when such a network is studied, the first reliable data often concern its interaction graph, so that the bound we establish can be used, in practice, to obtain valuable information about the numbe...

  11. Facilitation Dynamics and Localization Phenomena in Rydberg Lattice Gases with Position Disorder

    Science.gov (United States)

    Marcuzzi, Matteo; Minář, Jiří; Barredo, Daniel; de Léséleuc, Sylvain; Labuhn, Henning; Lahaye, Thierry; Browaeys, Antoine; Levi, Emanuele; Lesanovsky, Igor

    2017-02-01

    We explore the dynamics of Rydberg excitations in an optical tweezer array under antiblockade (or facilitation) conditions. Because of the finite temperature the atomic positions are randomly spread, an effect that leads to quenched correlated disorder in the interatomic interaction strengths. This drastically affects the facilitation dynamics as we demonstrate experimentally on the elementary example of two atoms. To shed light on the role of disorder in a many-body setting we show that here the dynamics is governed by an Anderson-Fock model, i.e., an Anderson model formulated on a lattice with sites corresponding to many-body Fock states. We first consider a one-dimensional atom chain in a limit that is described by a one-dimensional Anderson-Fock model with disorder on every other site, featuring both localized and delocalized states. We then illustrate the effect of disorder experimentally in a situation in which the system maps on a two-dimensional Anderson-Fock model on a trimmed square lattice. We observe a clear suppression of excitation propagation, which we ascribe to the localization of the many-body wave functions in Hilbert space.

  12. Locally optimal control under unknown dynamics with learnt cost function: application to industrial robot positioning

    Science.gov (United States)

    Guérin, Joris; Gibaru, Olivier; Thiery, Stéphane; Nyiri, Eric

    2017-01-01

    Recent methods of Reinforcement Learning have enabled to solve difficult, high dimensional, robotic tasks under unknown dynamics using iterative Linear Quadratic Gaussian control theory. These algorithms are based on building a local time-varying linear model of the dynamics from data gathered through interaction with the environment. In such tasks, the cost function is often expressed directly in terms of the state and control variables so that it can be locally quadratized to run the algorithm. If the cost is expressed in terms of other variables, a model is required to compute the cost function from the variables manipulated. We propose a method to learn the cost function directly from the data, in the same way as for the dynamics. This way, the cost function can be defined in terms of any measurable quantity and thus can be chosen more appropriately for the task to be carried out. With our method, any sensor information can be used to design the cost function. We demonstrate the efficiency of this method through simulating, with the V-REP software, the learning of a Cartesian positioning task on several industrial robots with different characteristics. The robots are controlled in joint space and no model is provided a priori. Our results are compared with another model free technique, consisting in writing the cost function as a state variable.

  13. Protein dynamics tunes excited state positions in light-harvesting complex II.

    Science.gov (United States)

    Vrandecic, Kamarniso; Rätsep, Margus; Wilk, Laura; Rusevich, Leonid; Golub, Maksym; Reppert, Mike; Irrgang, Klaus-Dieter; Kühlbrandt, Werner; Pieper, Jörg

    2015-03-12

    Light harvesting and excitation energy transfer in photosynthesis are relatively well understood at cryogenic temperatures up to ∼100 K, where crystal structures of several photosynthetic complexes including the major antenna complex of green plants (LHC II) are available at nearly atomic resolution. The situation is much more complex at higher or even physiological temperatures, because the spectroscopic properties of antenna complexes typically undergo drastic changes above ∼100 K. We have addressed this problem using a combination of quasielastic neutron scattering (QENS) and optical spectroscopy on native LHC II and mutant samples lacking the Chl 2/Chl a 612 pigment molecule. Absorption difference spectra of the Chl 2/Chl a 612 mutant of LHC II reveal pronounced changes of spectral position and their widths above temperatures as low as ∼80 K. The complementary QENS data indicate an onset of conformational protein motions at about the same temperature. This finding suggests that excited state positions in LHC II are affected by protein dynamics on the picosecond time scale. In more detail, this means that at cryogenic temperatures the antenna complex is trapped in certain protein conformations. At higher temperature, however, a variety of conformational substates with different spectral position may be thermally accessible. At the same time, an analysis of the widths of the absorption difference spectra of Chl 2/Chl a 612 reveals three different reorganization energies or Huang-Rhys factors in different temperature ranges, respectively. These findings imply that (dynamic) pigment-protein interactions fine-tune electronic energy levels and electron-phonon coupling of LHC II for efficient excitation energy transfer at physiological temperatures.

  14. Modelling dynamics and aerodynamic tests of a sport parachute jumper during flight in sitfly position.

    Science.gov (United States)

    Moniuszko, Justyna; Maryniak, Jerzy; Ladyżyńska-Kozdraś, Edyta

    2010-01-01

    Based on a model of a parachute jumper, for various body configurations in a sitting position, tests were carried out in an aerodynamic tunnel. Aerodynamic characteristics and dimensionless aerodynamic forces' coefficients were calculated. The tests were carried out for various configurations of the jumper's body. A universal mathematical model of a parachute jumper's body was prepared, thus enabling the analysis of the jumper's movement with a closed parachute in any position. In order to build the model, a digitized model of a jumper allowing changing the body configuration, making appropriate changes of the moment of inertia, distribution of the center of mass and the aerodynamic characteristics was adopted. Dynamic movement equations were derived for a jumper in a relative reference system. The mathematical model was formulated for a jumper with a variable body configuration during the flight, which can be realized through a change of the position and the speed of the parachute jumper's limbs. The model allows analyzing the motion of the jumper with a closed parachute. It is an important jump phase during an assault with delayed parachute opening in sports type jumping, e.g., Skydiving and in emergency jumps from higher altitudes for the parachute's opening to be safe.

  15. Time lags and the balance of positive and negative interactions in driving grassland community dynamics.

    Science.gov (United States)

    Farrer, Emily C; Goldberg, Deborah E; King, Aaron A

    2010-02-01

    Both facilitative and competitive interactions occur simultaneously among plants, and the net balance between them can vary over time. Despite this, recent model-fitting studies have found that negative interactions predominate. This suggests that more complex models may be necessary to uncover facilitation. Here we fitted models including seasonality, interannual variation, and time lags to survey data to test for patterns in positive and negative interactions among plants in a Michigan dry sand prairie. We hypothesized that interactions would be generally facilitative in this dry environment. Results indicate that most immediate (direct) interactions among dominant species are actually competitive, although interactions were more facilitative over the drier summer season. Interestingly, lagged density dependence was strong for all species in both seasons; it was positive for conspecific interactions and both positive and negative for heterospecific interactions. Observed lagged density dependence is likely due to effects from litter and/or past storage in rhizomes. Conspecific immediate and lagged interactions tended to be stronger than heterospecific interactions, suggesting that population dynamics in this community are driven mostly by conspecifics. Overall, the presence of strong lagged density dependence in this system suggests that it may be more widespread in plants than previously thought.

  16. Robust H∞ Control of Neutral System with Time-Delay for Dynamic Positioning Ships

    Directory of Open Access Journals (Sweden)

    Dawei Zhao

    2015-01-01

    Full Text Available Due to the input time-delay existing in most thrust systems of the ships, the robust H∞ controller is designed for the ship dynamic positioning (DP system with time-delay. The input delay system is turned to a neutral time-delay system by a state-derivative control law. The less conservative result is derived for the neutral system with state-derivative feedback by the delay-decomposition approach and linear matrix inequality (LMI. Finally, the numerical simulations demonstrate the asymptotic stability and robustness of the controller and verify that the designed DP controller is effective in the varying environment disturbances of wind, waves, and ocean currents.

  17. Mutual positional preference of IPMDH proteins for binding studied by coarse-grained molecular dynamics simulation

    Science.gov (United States)

    Ishioka, T.; Yamada, H.; Miyakawa, T.; Morikawa, R.; Akanuma, S.; Yamagishi, A.; Takasu, M.

    2016-12-01

    Proteins, which incorporate charged and hydrophobic amino acid residues, are useful as a material of nanotechnology. Among these proteins, IPMDH (3-isopropylmalate dehydrogenase), which has thermal stability, has potential as a material of nanofiber. In this study, we performed coarse-grained molecular dynamics simulation of IPMDH using MARTINI force fields, and we investigated the orientation for the binding of IPMDH. In simulation, we analyzed wild type of IPMDH and the mutated IPMDH proteins, where 13, 20, 27, 332, 335 and 338th amino acid residues are replaced by lysine residues which have positive charge and by glutamic acid residues which have negative charge. Since the binding of mutated IPMDH is advantageous compared with the binding of wild type for one orientation, we suggest that the Coulomb interaction for the binding of IPMDH is important.

  18. 动力定位(DP)系统简介%Investigation of Dynamic Positioning System

    Institute of Scientific and Technical Information of China (English)

    王卫卫

    2014-01-01

    随着海洋工程项目的蓬勃发展,动力定位系统(简称DP系统)的应用已越来越广泛。本文对DP系统等级、工作原理以及根据船级社不同入级符号的设备配置等作了简单的介绍,希望能够对大家以后的开发设计及生产有所帮助。%The application of Dynamic Positioning System (DP system) is more and more popular because of development of ocean project. The article introduce the level of DP system, work principle, the requirement of equipment according to different DP notations. I hope it is helpful to exploder, design and production in the future.

  19. Principles supporting dynamic clinical care teams: an American College of Physicians position paper.

    Science.gov (United States)

    Doherty, Robert B; Crowley, Ryan A

    2013-11-05

    The U.S. health care system is undergoing a shift from individual clinical practice toward team-based care. This move toward team-based care requires fresh thinking about clinical leadership and responsibilities to ensure that the unique skills of each clinician are used to provide the best care for the patient as the patient's needs dictate, while the team as a whole must work together to ensure that all aspects of a patient's care are coordinated for the benefit of the patient. In this position paper, the American College of Physicians offers principles, definitions, and examples to dissolve barriers that prevent movement toward dynamic clinical care teams. These principles offer a framework for an evolving, updated approach to health care delivery, providing policy guidance that can be useful to clinical teams in organizing the care processes and clinician responsibilities consistent with professionalism.

  20. Existence of positive solutions for semipositone dynamic system on time scales

    Directory of Open Access Journals (Sweden)

    You-Wei Zhang

    2008-08-01

    Full Text Available In this paper, we study the following semipositone dynamic system on time scales $$displaylines{ -x^{DeltaDelta}(t=f(t,y+p(t, quad tin(0,T_{mathbb{T}},cr -y^{DeltaDelta}(t=g(t,x, quad tin(0,T_{mathbb{T}},cr x(0=x(sigma^{2}(T=0, cr alpha{y(0}-eta{y^{Delta}{(0}}= gamma{y(sigma(T}+delta{y^{Delta}(sigma(T}=0. }$$ Using fixed point index theory, we show the existence of at least one positive solution. The interesting point is the that nonlinear term is allowed to change sign and may tend to negative infinity.

  1. Dynamic Characteristics of Positive Pulsed Dielectric Barrier Discharge for Ozone Generation in Air

    Science.gov (United States)

    Wei, Linsheng; Peng, Bangfa; Li, Ming; Zhang, Yafang; Hu, Zhaoji

    2016-02-01

    A comprehensive dynamic model consisting of 66 reactions and 24 species is developed to investigate the dynamic characteristics of ozone generation by positive pulsed dielectric barrier discharge (DBD) using parallel-plate reactor in air. The electron energy conservation equation is coupled to the electron continuity equation, the heavy species continuity equation, and Poisson's equation for a better description. The reliability of the model is experimentally confirmed. The model can be used to predict the temporal and spatial evolution of species, as well as streamer propagation. The simulation results show that electron density increases nearly exponentially in the direction to the anode at the electron avalanche. Streamer propagation velocity is about 5.26 × 104 m/s from anode to cathode in the simulated condition. The primary positive ion, negative ion, and excited species are O2+, O3- and O2(1Δg) in pulsed DBD in air, respectively. N2O has the largest density among nitrogen oxides. e and N2+ densities in the streamer head increase gradually to maximum values with the development of the streamer. Meanwhile, the O2+, O, O3, N2(A3Σ) and N2O densities reach maximum values in the vicinity of the anode. supported by National Natural Science Foundation of China (Nos. 51366012 and 11105067), Jiangxi Province Young Scientists (Jinggang Star) Cultivation Plan of China (No. 20133BCB23008), Natural Science Foundation of Jiangxi, China (No. 20151BAB206047) and Jiangxi Province Higher School Science and Technology Landing Plan of China (No. KJLD-14015)

  2. Soil Redox Dynamics Vary with Landscape Position and Hydroperiod in the Pantanal Wetland Ecosystem

    Science.gov (United States)

    Couto, E. G.; Johnson, M. S.; Pinto-jr, O.; Leite, N. K.

    2012-12-01

    The Pantanal wetland ecosystem of central South America is the largest tropical wetland complex in the world. Nevertheless, biogeochemistry in the Pantanal is quite limited. A unimodal precipitation regime averages approximately 1200 mm y-1 during the six-month rainy season, leading to seasonal flooding on much, but not all, of the landscape. We investigated the impact of landscape position and hydroperiod on soil redox potential (Eh) in four research locations in the Northern Pantanal near Poconé, Mato Grosso: two locations subject to flooding (a flooded forest and a flooded scrub forest) and two locations with infrequent surface flooding (tree islands known as cordilheiras). Redox sensors were installed at 10 cm and 30 cm depths at each of the four locations with half-hourly data recorded over all hydro-periods (dry season, rising water, flood and falling water). Here we summarize results to date in this ongoing study. Reducing conditions were observed in response to both precipitation events saturating soil from the surface downward, as well as in response to regional flooding dynamics that saturate soil from below. These are helping to guide design of a study on methane dynamics in the Pantanal wetland complex.

  3. Systems approach to studying animal sociality: individual position versus group organization in dynamic social network models.

    Directory of Open Access Journals (Sweden)

    Karlo Hock

    Full Text Available Social networks can be used to represent group structure as a network of interacting components, and also to quantify both the position of each individual and the global properties of a group. In a series of simulation experiments based on dynamic social networks, we test the prediction that social behaviors that help individuals reach prominence within their social group may conflict with their potential to benefit from their social environment. In addition to cases where individuals were able to benefit from improving both their personal relative importance and group organization, using only simple rules of social affiliation we were able to obtain results in which individuals would face a trade-off between these factors. While selection would favor (or work against social behaviors that concordantly increase (or decrease, respectively fitness at both individual and group level, when these factors conflict with each other the eventual selective pressure would depend on the relative returns individuals get from their social environment and their position within it. The presented results highlight the importance of a systems approach to studying animal sociality, in which the effects of social behaviors should be viewed not only through the benefits that those provide to individuals, but also in terms of how they affect broader social environment and how in turn this is reflected back on an individual's fitness.

  4. SPOT14-Positive Neural Stem/Progenitor Cells in the Hippocampus Respond Dynamically to Neurogenic Regulators

    Directory of Open Access Journals (Sweden)

    Marlen Knobloch

    2014-11-01

    Full Text Available Proliferation of neural stem/progenitor cells (NSPCs in the adult brain is tightly controlled to prevent exhaustion and to ensure proper neurogenesis. Several extrinsic stimuli affect NSPC regulation. However, the lack of unique markers led to controversial results regarding the in vivo behavior of NSPCs to different stimuli. We recently identified SPOT14, which controls NSPC proliferation through regulation of de novo lipogenesis, selectively in low-proliferating NSPCs. Whether SPOT14-expressing (SPOT14+ NSPCs react in vivo to neurogenic regulators is not known. We show that aging is accompanied by a marked disappearance of SPOT14+ NSPCs, whereas running, a positive neurogenic stimulus, increases proliferation of SPOT14+ NSPCs. Furthermore, transient depletion of highly proliferative cells recruits SPOT14+ NSPCs into the proliferative pool. Additionally, we have established endogenous SPOT14 protein staining, reflecting transgenic SPOT14-GFP expression. Thus, our data identify SPOT14 as a potent marker for adult NSPCs that react dynamically to positive and negative neurogenic regulators.

  5. Systems approach to studying animal sociality: individual position versus group organization in dynamic social network models.

    Science.gov (United States)

    Hock, Karlo; Ng, Kah Loon; Fefferman, Nina H

    2010-12-23

    Social networks can be used to represent group structure as a network of interacting components, and also to quantify both the position of each individual and the global properties of a group. In a series of simulation experiments based on dynamic social networks, we test the prediction that social behaviors that help individuals reach prominence within their social group may conflict with their potential to benefit from their social environment. In addition to cases where individuals were able to benefit from improving both their personal relative importance and group organization, using only simple rules of social affiliation we were able to obtain results in which individuals would face a trade-off between these factors. While selection would favor (or work against) social behaviors that concordantly increase (or decrease, respectively) fitness at both individual and group level, when these factors conflict with each other the eventual selective pressure would depend on the relative returns individuals get from their social environment and their position within it. The presented results highlight the importance of a systems approach to studying animal sociality, in which the effects of social behaviors should be viewed not only through the benefits that those provide to individuals, but also in terms of how they affect broader social environment and how in turn this is reflected back on an individual's fitness.

  6. Design of a dynamic positioning system using model-based control

    Directory of Open Access Journals (Sweden)

    Asgeir J. Sørensen

    1996-04-01

    Full Text Available A dynamic positioning (DP system includes different control functions for automatic positioning and guidance of marine vessels by means of thruster and propeller actions. This paper describes the control functions which provide station-keeping and tracking. The DP controller is designed using model-based control, where a new modified LQG feedback controller and a model reference feedforward controller are applied. A reference model calculates appropriate reference trajectories. Since it is not desirable nor even possible to counteract the wave-frequency movement caused by first-order wave loads, the control action of the propulsion system should be produced by the low frequency part of the vessel movement caused by current, wind and second-order mean and slowly varying wave loads. A Kalman filter based state estimator and a Luenberger observer are used to compute the low-frequency feedback and feedforward control signals. Full-scale experiments with a supply vessel demonstrate the performance of the proposed controller.

  7. Systems Approach to Studying Animal Sociality: Individual Position versus Group Organization in Dynamic Social Network Models

    Science.gov (United States)

    Hock, Karlo; Ng, Kah Loon; Fefferman, Nina H.

    2010-01-01

    Social networks can be used to represent group structure as a network of interacting components, and also to quantify both the position of each individual and the global properties of a group. In a series of simulation experiments based on dynamic social networks, we test the prediction that social behaviors that help individuals reach prominence within their social group may conflict with their potential to benefit from their social environment. In addition to cases where individuals were able to benefit from improving both their personal relative importance and group organization, using only simple rules of social affiliation we were able to obtain results in which individuals would face a trade-off between these factors. While selection would favor (or work against) social behaviors that concordantly increase (or decrease, respectively) fitness at both individual and group level, when these factors conflict with each other the eventual selective pressure would depend on the relative returns individuals get from their social environment and their position within it. The presented results highlight the importance of a systems approach to studying animal sociality, in which the effects of social behaviors should be viewed not only through the benefits that those provide to individuals, but also in terms of how they affect broader social environment and how in turn this is reflected back on an individual's fitness. PMID:21203425

  8. Application of the nonlinear, double-dynamic Taguchi method to the precision positioning device using combined piezo-VCM actuator.

    Science.gov (United States)

    Liu, Yung-Tien; Fung, Rong-Fong; Wang, Chun-Chao

    2007-02-01

    In this research, the nonlinear, double-dynamic Taguchi method was used as design and analysis methods for a high-precision positioning device using the combined piezo-voice-coil motor (VCM) actuator. An experimental investigation into the effects of two input signals and three control factors were carried out to determine the optimum parametric configuration of the positioning device. The double-dynamic Taguchi method, which permits optimization of several control factors concurrently, is particularly suitable for optimizing the performance of a positioning device with multiple actuators. In this study, matrix experiments were conducted with L9(3(4)) orthogonal arrays (OAs). The two most critical processes for the optimization of positioning device are the identification of the nonlinear ideal function and the combination of the double-dynamic signal factors for the ideal function's response. The driving voltage of the VCM and the waveform amplitude of the PZT actuator are combined into a single quality characteristic to evaluate the positioning response. The application of the double-dynamic Taguchi method, with dynamic signal-to-noise ratio (SNR) and L9(3(4)) OAs, reduced the number of necessary experiments. The analysis of variance (ANOVA) was applied to set the optimum parameters based on the high-precision positioning process.

  9. DNA as a Powerful Tool for Morphology Control, Spatial Positioning, and Dynamic Assembly of Nanoparticles

    Science.gov (United States)

    2015-01-01

    Conspectus Several properties of nanomaterials, such as morphologies (e.g., shapes and surface structures) and distance dependent properties (e.g., plasmonic and quantum confinement effects), make nanomaterials uniquely qualified as potential choices for future applications from catalysis to biomedicine. To realize the full potential of these nanomaterials, it is important to demonstrate fine control of the morphology of individual nanoparticles, as well as precise spatial control of the position, orientation, and distances between multiple nanoparticles. In addition, dynamic control of nanomaterial assembly in response to multiple stimuli, with minimal or no error, and the reversibility of the assemblies are also required. In this Account, we summarize recent progress of using DNA as a powerful programmable tool to realize the above goals. First, inspired by the discovery of genetic codes in biology, we have discovered DNA sequence combinations to control different morphologies of nanoparticles during their growth process and have shown that these effects are synergistic or competitive, depending on the sequence combination. The DNA, which guides the growth of the nanomaterial, is stable and retains its biorecognition ability. Second, by taking advantage of different reactivities of phosphorothioate and phosphodiester backbone, we have placed phosphorothioate at selective positions on different DNA nanostructures including DNA tetrahedrons. Bifunctional linkers have been used to conjugate phosphorothioate on one end and bind nanoparticles or proteins on the other end. In doing so, precise control of distances between two or more nanoparticles or proteins with nanometer resolution can be achieved. Furthermore, by developing facile methods to functionalize two hemispheres of Janus nanoparticles with two different DNA sequences regioselectively, we have demonstrated directional control of nanomaterial assembly, where DNA strands with specific hybridization serve as

  10. Airflow behavior changes in upper airway caused by different head and neck positions: Comparison by computational fluid dynamics.

    Science.gov (United States)

    Wei, Wei; Huang, Shi-Wei; Chen, Lian-Hua; Qi, Yang; Qiu, Yi-Min; Li, Shi-Tong

    2017-02-08

    The feasibility of computational fluid dynamics (CFD) to evaluate airflow characteristics in different head and neck positions has not been established. This study compared the changes in volume and airflow behavior of the upper airway by CFD simulation to predict the influence of anatomical and physiological airway changes due to different head-neck positions on mechanical ventilation. One awake volunteer with no risk of difficult airway underwent computed tomography in neutral position, extension position (both head and neck extended), and sniffing position (head extended and neck flexed). Three-dimensional airway models of the upper airway were reconstructed. The total volume (V) and narrowest area (Amin) of the airway models were measured. CFD simulation with an Spalart-Allmaras model was performed to characterize airflow behavior in neutral, extension, and sniffing positions of closed-mouth and open-mouth ventilation. The comparison result for V was neutral position was nearly 3.0 times that in neutral position and 1.7 times that in extension position. The pressure drop and velocity increasing were more obvious in neutral than sniffing or extension position at the same airflow rate. In sniffing position, pressure differences decreased and velocity remained almost constant. Recirculation airflow was generated near the subglottic region in neutral and extension positions. Sniffing position improves airway patency by increasing airway volume and decreasing airway resistance, suggesting that sniffing position may be the optimal choice for mask ventilation.

  11. Alanine scan of core positions in ubiquitin reveals links between dynamics, stability, and function.

    Science.gov (United States)

    Lee, Shirley Y; Pullen, Lester; Virgil, Daniel J; Castañeda, Carlos A; Abeykoon, Dulith; Bolon, Daniel N A; Fushman, David

    2014-04-03

    Mutations at solvent-inaccessible core positions in proteins can impact function through many biophysical mechanisms including alterations to thermodynamic stability and protein dynamics. As these properties of proteins are difficult to investigate, the impacts of core mutations on protein function are poorly understood for most systems. Here, we determined the effects of alanine mutations at all 15 core positions in ubiquitin on function in yeast. The majority (13 of 15) of alanine substitutions supported yeast growth as the sole ubiquitin. Both the two null mutants (I30A and L43A) were less stable to temperature-induced unfolding in vitro than wild type (WT) but were well folded at physiological temperatures. Heteronuclear NMR studies indicated that the L43A mutation reduces temperature stability while retaining a ground-state structure similar to WT. This structure enables L43A to bind to common ubiquitin receptors in vitro. Many of the core alanine ubiquitin mutants, including one of the null variants (I30A), exhibited an increased accumulation of high-molecular-weight species, suggesting that these mutants caused a defect in the processing of ubiquitin-substrate conjugates. In contrast, L43A exhibited a unique accumulation pattern with reduced levels of high-molecular-weight species and undetectable levels of free ubiquitin. When conjugation to other proteins was blocked, L43A ubiquitin accumulated as free ubiquitin in yeast. Based on these findings, we speculate that ubiquitin's stability to unfolding may be required for efficient recycling during proteasome-mediated substrate degradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Impact of time delays on oscillatory dynamics of interlinked positive and negative feedback loops

    Science.gov (United States)

    Huang, Bo; Tian, Xinyu; Liu, Feng; Wang, Wei

    2016-11-01

    Interlinking a positive feedback loop (PFL) with a negative feedback loop (NFL) constitutes a typical motif in genetic networks, performing various functions in cell signaling. How time delay in feedback regulation affects the dynamics of such systems still remains unclear. Here, we investigate three systems of interlinked PFL and NFL with time delays: a synthetic genetic oscillator, a three-node circuit, and a simplified single-node model. The stability of steady states and the routes to oscillation in the single-node model are analyzed in detail. The amplitude and period of oscillations vary with a pointwise periodicity over a range of time delay. Larger-amplitude oscillations can be induced when the PFL has an appropriately long delay, in comparison with the PFL with no delay or short delay; this conclusion holds true for all the three systems. We unravel the underlying mechanism for the above effects via analytical derivation under a limiting condition. We also develop a stochastic algorithm for simulating a single reaction with two delays and show that robust oscillations can be maintained by the PFL with a properly long delay in the single-node system. This work presents an effective method for constructing robust large-amplitude oscillators and interprets why similar circuit architectures are engaged in timekeeping systems such as circadian clocks.

  13. Dynamics of atomic kinetics in a pulsed positive-column discharge at 100 Pa

    Science.gov (United States)

    Franek, J. B.; Nogami, S. H.; Koepke, M. E.; Demidov, V. I.; Barnat, E. V.

    2017-01-01

    Temporal measurements of the electron density, metastable-atom density, and reduced electric field demonstrate that four orders of magnitude variation in the dynamic range of the electron-atom collision-induced excitation rates takes place during the 2.0 kV height, 40 µs duration repeating pulse applied to a 100 Pa (1 Torr), argon positive column in a hollow-cathode discharge. Correlation between metastable-atom density and emission-line ratio is demonstrated to be sufficiently reliable to infer one quantity based on the measurement of the other quantity during the Initiation, Transient, and Post-Transient spectroscopic stages of the pulse. Observed emission-line ratio and the predicted emission-line ratio are in quantitative agreement with each other in the Transient and Post-Transient stages of the discharge and are in qualitative agreement with each other in the Initiation stage of the discharge. Reasonable assumptions regarding the interpretation of the electron energy probability function (EEPF), as it starts off being Druyvesteyn and becomes more Maxwellian later with the increasing electron density, is key to interpreting the correlation and explaining the temporal behavior of the emission-line ratio in all stages of the discharge.

  14. Remote handling dynamical modelling: assessment on new approach to enhance positioning accuracy with heavy load manipulation

    Energy Technology Data Exchange (ETDEWEB)

    Gagarina-Sasia, T.; David, O.; Dubus, G.; Perrot, Y.; Riwain, A. [CEA, LIST, 92 - Fontenay aux Roses (France). Service de Robotique Interactive; Gabellini, E.; Pretot, P. [SAMTECH, 91 - Massy (France)

    2007-07-01

    In vessel maintenance work in Fusion Tokamak will be carried out with help several sets of robotic devices. Heavy loads handling in constrained space is identified by all players of the RH community as a key-issue in the latest Fusion Tokamak facilities. To deal with high-level dexterity tasks, high payload to mass ratio and limited operating space, RH equipment designers can only propose systems whose mechanical flexibility is no longer negligible and need to be taken into account in the control scheme. Traditional approaches where control system only includes a linear model of deformation of the structure leads to poor positioning accuracy. Uncontrolled or under evaluated errors could be damaging for in-vessel components during maintenance operations in the Tokamak facility. To address the control of complex flexible systems, we will investigate the use of specific mechanical software that combines both finite element and kinematical joints analyses, with a strong-coupled formulation, to perform system dynamics simulations. This procedure will be applied on a single axis mock up robotic joint with highly flexible structure. A comparison of experimental results with the traditional linear approach and the specified software model will be carried out. Benefits introduced by this new approach will finally be assessed in view of RH design or specification in the field of RH in Fusion Tokamak scale such as ITER. (orig.)

  15. [Cells in the system of multicelular organisms from positions of non-linear dynamics].

    Science.gov (United States)

    Kotolupov, V A; Isaeva, V V

    2012-01-01

    The organism physiological systems forming a hierarchic network with mutual dependence and subordination can be considered as systems with non-linear dynamics including positive and negative feedbacks. In the course of evolution there occurred selection of robust, flexible, modular systems capable for adaptive self-organization by non-linear interaction of components, which leads to formation of the ordered in space and time robust and plastic organization of the whole. Cells of multicellular organisms are capable for coordinated "social" behavior with formation of ordered cell assemblies, which provides a possibility of morphological and functional variability correlating with manifestations of the large spectrum of adaptive reactions. The multicellular organism is the multilevel system with hierarchy of numerous subsystems capable for adaptive self-organization; disturbance of their homeostasis can lead to pathological changes. The healthy organism regulates homeostasis, self-renewal, differentiation, and apoptosis of cells serving its parts and construction blocks by preserving its integrity and controlling behavior of cells. The systemic approach taking into account biological regularities of the appearance and development of functions in evolution of multicellular organisms opens new possibilities for diagnostics and treatment of many diseases.

  16. Bloodstain Pattern Analysis: implementation of a fluid dynamic model for position determination of victims

    Science.gov (United States)

    Laan, Nick; de Bruin, Karla G.; Slenter, Denise; Wilhelm, Julie; Jermy, Mark; Bonn, Daniel

    2015-06-01

    Bloodstain Pattern Analysis is a forensic discipline in which, among others, the position of victims can be determined at crime scenes on which blood has been shed. To determine where the blood source was investigators use a straight-line approximation for the trajectory, ignoring effects of gravity and drag and thus overestimating the height of the source. We determined how accurately the location of the origin can be estimated when including gravity and drag into the trajectory reconstruction. We created eight bloodstain patterns at one meter distance from the wall. The origin’s location was determined for each pattern with: the straight-line approximation, our method including gravity, and our method including both gravity and drag. The latter two methods require the volume and impact velocity of each bloodstain, which we are able to determine with a 3D scanner and advanced fluid dynamics, respectively. We conclude that by including gravity and drag in the trajectory calculation, the origin’s location can be determined roughly four times more accurately than with the straight-line approximation. Our study enables investigators to determine if the victim was sitting or standing, or it might be possible to connect wounds on the body to specific patterns, which is important for crime scene reconstruction.

  17. High-rate RTK and PPP multi-GNSS positioning for small-scale dynamic displacements monitoring

    Science.gov (United States)

    Paziewski, Jacek; Sieradzki, Rafał; Baryła, Radosław; Wielgosz, Pawel

    2017-04-01

    The monitoring of dynamic displacements and deformations of engineering structures such as buildings, towers and bridges is of great interest due to several practical and theoretical reasons. The most important is to provide information required for safe maintenance of the constructions. High temporal resolution and precision of GNSS observations predestine this technology to be applied to most demanding application in terms of accuracy, availability and reliability. GNSS technique supported by appropriate processing methodology may meet the specific demands and requirements of ground and structures monitoring. Thus, high-rate multi-GNSS signals may be used as reliable source of information on dynamic displacements of ground and engineering structures, also in real time applications. In this study we present initial results of application of precise relative GNSS positioning for detection of small scale (cm level) high temporal resolution dynamic displacements. Methodology and algorithms applied in self-developed software allowing for relative positioning using high-rate dual-frequency phase and pseudorange GPS+Galileo observations are also given. Additionally, an approach was also made to use the Precise Point Positioning technique to such application. In the experiment were used the observations obtained from high-rate (20 Hz) geodetic receivers. The dynamic displacements were simulated using specially constructed device moving GNSS antenna with dedicated amplitude and frequency. The obtained results indicate on possibility of detection of dynamic displacements of the GNSS antenna even at the level of few millimetres using both relative and Precise Point Positioning techniques after suitable signals processing.

  18. A dynamical model of general intelligence: The positive manifold of intelligence by mutualism

    NARCIS (Netherlands)

    van der Maas, H.L.J.; Dolan, C.V.; Grasman, R.P.P.P.; Wicherts, J.M.; Huizenga, H.M.; Raijmakers, M.E.J.

    2006-01-01

    Scores on cognitive tasks used in intelligence tests correlate positively with each other, that is, they display a positive manifold of correlations. The positive manifold is often explained by positing a dominant latent variable, the g factor, associated with a single quantitative cognitive or biol

  19. Cross-cultural patterns in dynamic ratings of positive and negative natural emotional behaviour.

    Directory of Open Access Journals (Sweden)

    Ian Sneddon

    Full Text Available BACKGROUND: Studies of cross-cultural variations in the perception of emotion have typically compared rates of recognition of static posed stimulus photographs. That research has provided evidence for universality in the recognition of a range of emotions but also for some systematic cross-cultural variation in the interpretation of emotional expression. However, questions remain about how widely such findings can be generalised to real life emotional situations. The present study provides the first evidence that the previously reported interplay between universal and cultural influences extends to ratings of natural, dynamic emotional stimuli. METHODOLOGY/PRINCIPAL FINDINGS: Participants from Northern Ireland, Serbia, Guatemala and Peru used a computer based tool to continuously rate the strength of positive and negative emotion being displayed in twelve short video sequences by people from the United Kingdom engaged in emotional conversations. Generalized additive mixed models were developed to assess the differences in perception of emotion between countries and sexes. Our results indicate that the temporal pattern of ratings is similar across cultures for a range of emotions and social contexts. However, there are systematic differences in intensity ratings between the countries, with participants from Northern Ireland making the most extreme ratings in the majority of the clips. CONCLUSIONS/SIGNIFICANCE: The results indicate that there is strong agreement across cultures in the valence and patterns of ratings of natural emotional situations but that participants from different cultures show systematic variation in the intensity with which they rate emotion. Results are discussed in terms of both 'in-group advantage' and 'display rules' approaches. This study indicates that examples of natural spontaneous emotional behaviour can be used to study cross-cultural variations in the perception of emotion.

  20. IMPLEMENTATION APPROACHES DURING SIMULATION OF ENERGY PROCESSES FOR A DYNAMICALLY POSITIONED SHIP

    Directory of Open Access Journals (Sweden)

    V.V. Budashko

    2015-12-01

    Full Text Available Purpose. Creation of a mathematical model of the ship's power plant (SPP combined propulsion complexes (CPC that takes into account the behavior of all objects, including the ship itself, the transfer of power from the medium speed diesel generators on the propellers, which will allow to take into account the hydrodynamic properties of the vessel and their impact on the energy processes in SPP CPC. Methodology. The analysis of energy processes in the SPP CPC in different operating conditions resulted in creation of a strategy for constructing mathematical models of SPP CPC. This strategy is based on the implementation on the vector plane resulting power characteristics of SPP vectors disturbances, leading to the deviation of the hydrodynamic characteristics of the ship during operation dynamic positioning. The result allowed to consider not only the features of setting PID-governors of frequency converters of electric thrusters but the automatic voltage regulators of medium speed diesel generators as well. Results. Within the research work a software package Ships_CPC in MatLab/Simulink was developed under the state budget project «Concepts, technologies and ways of improving ship power plants combined propulsion complexes» at the Department of Electromechanics and Electrical Engineering of Odessa National Maritime Academy. Originality. This complex represents a set of functional blocks of the components SPP CPC, built on the principle of «input-output». The simulation results demonstrate the ability to use software package Ships_CPC to study the effect of various settings on the energy regulators of processes SPP CPC, which can develop and integrate the different strategies of automatic voltage regulators. Practical value. Since software complex Ships_CPC was developed under Open system technology, it can reorganize, re-tune and integrate in processes of any difficulties with further completion in the form of a universal structure.

  1. Measurement and inference of profile soil-water dynamics at different hillslope positions in a semiarid agricultural watershed

    Science.gov (United States)

    Green, Timothy R.; Erskine, Robert H.

    2011-12-01

    Dynamics of profile soil water vary with terrain, soil, and plant characteristics. The objectives addressed here are to quantify dynamic soil water content over a range of slope positions, infer soil profile water fluxes, and identify locations most likely influenced by multidimensional flow. The instrumented 56 ha watershed lies mostly within a dryland (rainfed) wheat field in semiarid eastern Colorado. Dielectric capacitance sensors were used to infer hourly soil water content for approximately 8 years (minus missing data) at 18 hillslope positions and four or more depths. Based on previous research and a new algorithm, sensor measurements (resonant frequency) were rescaled to estimate soil permittivity, then corrected for temperature effects on bulk electrical conductivity before inferring soil water content. Using a mass-conservation method, we analyzed multitemporal changes in soil water content at each sensor to infer the dynamics of water flux at different depths and landscape positions. At summit positions vertical processes appear to control profile soil water dynamics. At downslope positions infrequent overland flow and unsaturated subsurface lateral flow appear to influence soil water dynamics. Crop water use accounts for much of the variability in soil water between transects that are either cropped or fallow in alternating years, while soil hydraulic properties and near-surface hydrology affect soil water variability across landscape positions within each management zone. The observed spatiotemporal patterns exhibit the joint effects of short-term hydrology and long-term soil development. Quantitative methods of analyzing soil water patterns in space and time improve our understanding of dominant soil hydrological processes and provide alternative measures of model performance.

  2. Wave packet dynamics for a system with position and time-dependent effective mass in an infinite square well

    Energy Technology Data Exchange (ETDEWEB)

    Vubangsi, M.; Tchoffo, M.; Fai, L. C. [Mesoscopic and Multilayer Structures Laboratory, Physics Department, University of Dschang, P.O. Box 417 Dschang (Cameroon); Pisma’k, Yu. M. [Department of Theoretical Physics, Saint Petersburg State University, Saint Petersburg (Russian Federation)

    2015-12-15

    The problem of a particle with position and time-dependent effective mass in a one-dimensional infinite square well is treated by means of a quantum canonical formalism. The dynamics of a launched wave packet of the system reveals a peculiar revival pattern that is discussed. .

  3. [The optimal insertion position of the lumbar interspinous dynamic stabilization device (Coflex): a biomechanical evaluation].

    Science.gov (United States)

    Zu, Dan; Hai, Yong; Lu, Shibao; Yang, Jincai; Liu, Yuzeng; Liu, Tie; Meng, Xianglong; Zhou, Lijin; Pang, Chuan

    2014-03-01

    To evaluate the optimal insertion position of the Coflex lumbar interspinous dynamic stabilization device. Six fresh adult human cadaveric lumbar spine specimens (L1-L5) were mounted in a materials testing machine by embedding to clamps with L1 and L5 vertebrae. L3-4 motion segment of each specimen was operated by selective decompression and Coflex interspinous device insertion. The L3 and L4 vertebrae was inserted one needle attached with four marker points respectively, which were used to record the range of motion (ROM). Each lumbar spine specimen was tested according to the loading sequence at 5 groups: intact (keeping lumbar ligamenta and facet joints intact) group, partial destabilized (resection of L3-4 interspinous ligamenta, ligamentum flavum, facet capsule, and bilateral resection 50% of L3 inferior facets) group, 10 mm insertion (distance between apex of U-shaped Coflex and dural sac was 10 mm)group, 5 mm insertion (distance was 5 mm)group, and 0 mm insertion (distance was 0 mm)group. Each lumbar spine specimen was tested repeatedly 3 times according to a loading sequence consisting of flexion, extension, left/right lateral bending, left/right axial rotation, loaded with pure moments of 8 N·m, and was recorded the ROM of operative segment at the third time. ROM of 5 groups in 6 directions respectively were analyzed with one-way ANOVA test and multiple comparisons were based on LSD method. The means ROM of 5 groups were not all equal in flexion, extension, left/right lateral bending, left/right axial rotation (F = 8.472, 18.301, 7.700, 12.473, 16.809, 6.624; all P 0.05). The ROM of the 5 mm and 0 mm insertion group were no significant differences comparing with the intact group in flexion, extension, left/right axial rotation (P > 0.05), but it were significant differences comparing with the partial destabilized group in the same directions (5 mm insertion group: t = 3.19, 6.34, 5.26, 3.43, all P bending between the 5mm/0mm insertion groups and the

  4. Conformational Dynamics and Proton Relay Positioning in Nickel Catalysts for Hydrogen Production and Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Franz, James A.; O' Hagan, Molly J.; Ho, Ming-Hsun; Liu, Tianbiao L.; Helm, Monte L.; Lense, Sheri; DuBois, Daniel L.; Shaw, Wendy J.; Appel, Aaron M.; Raugei, Simone; Bullock, R. Morris

    2013-12-09

    The [Ni(PR2NR’2)2]2+ catalysts, (where PR2NR´2 is 1,5-R´-3,7-R-1,5-diaza-3,7-diphosphacyclooctane), are some of the fastest reported for hydrogen production and oxidation, however, chair/boat isomerization and the presence of a fifth solvent ligand have the potential to slow catalysis by incorrectly positioning the pendant amines or blocking the addition of hydrogen. Here, we report the structural dynamics of a series of [Ni(PR2NR’2)2]n+ complexes, characterized by NMR spectroscopy and theoretical modeling. A fast exchange process was observed for the [Ni(CH3CN)(PR2NR’2)2]2+ complexes which depends on the ligand. This exchange process was identified to occur through a three step mechanism including dissociation of the acetonitrile, boat/chair isomerization of each of the four rings identified by the phosphine ligands (including nitrogen inversion), and reassociation of acetonitrile on the opposite side of the complex. The rate of the chair/boat inversion can be influenced by varying the substituent on the nitrogen atom, but the rate of the overall exchange process is at least an order of magnitude faster than the catalytic rate in acetonitrile demonstrating that the structural dynamics of the [Ni(PR2NR´2)2]2+ complexes does not hinder catalysis. This material is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under FWP56073. Research by J.A.F., M.O., M-H. H., M.L.H, D.L.D. A.M.A., S. R. and R.M.B. was carried out in the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. W.J.S. and S.L. were funded by the DOE Office of Science Early Career Research Program through the Office of Basic Energy Sciences. T.L. was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences

  5. An Approach for High-precision Stand-alone Positioning in a Dynamic Environment

    Science.gov (United States)

    Halis Saka, M.; Metin Alkan, Reha; Ozpercin, Alişir

    2015-04-01

    In this study, an algorithm is developed for precise positioning in dynamic environment utilizing a single geodetic GNSS receiver using carrier phase data. In this method, users should start the measurement on a known point near the project area for a couple of seconds making use of a single dual-frequency geodetic-grade receiver. The technique employs iono-free carrier phase observations with precise products. The equation of the algorithm is given below; Sm(t(i+1))=SC(ti)+[ΦIF (t(i+1) )-ΦIF (ti)] where, Sm(t(i+1)) is the phase-range between satellites and the receiver, SC(ti) is the initial range computed from the initial known point coordinates and the satellite coordinates and ΦIF is the ionosphere-free phase measurement (in meters). Tropospheric path delays are modelled using the standard tropospheric model. To accomplish the process, an in-house program was coded and some functions were adopted from Easy-Suite available at http://kom.aau.dk/~borre/easy. In order to assess the performance of the introduced algorithm in a dynamic environment, a dataset from a kinematic test measurement was used. The data were collected from a kinematic test measurement in Istanbul, Turkey. In the test measurement, a geodetic dual-frequency GNSS receiver, Ashtech Z-Xtreme, was set up on a known point on the shore and a couple of epochs were recorded for initialization. The receiver was then moved to a vessel and data were collected for approximately 2.5 hours and the measurement was finalized on a known point on the shore. While the kinematic measurement on the vessel were carried out, another GNSS receiver was set up on a geodetic point with known coordinates on the shore and data were collected in static mode to calculate the reference trajectory of the vessel using differential technique. The coordinates of the vessel were calculated for each measurement epoch with the introduced method. With the purpose of obtaining more robust results, all coordinates were calculated

  6. DMPD: Cellular reprogramming by gram-positive bacterial components: a review. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16885502 Cellular reprogramming by gram-positive bacterial components: a review. Bu...(.csml) Show Cellular reprogramming by gram-positive bacterial components: a review. PubmedID 16885502 Title... Cellular reprogramming by gram-positive bacterial components: a review. Authors

  7. Effect of Nasal Obstruction on Continuous Positive Airway Pressure Treatment: Computational Fluid Dynamics Analyses.

    Directory of Open Access Journals (Sweden)

    Tadashi Wakayama

    Full Text Available Nasal obstruction is a common problem in continuous positive airway pressure (CPAP therapy for obstructive sleep apnea and limits treatment compliance. The purpose of this study is to model the effects of nasal obstruction on airflow parameters under CPAP using computational fluid dynamics (CFD, and to clarify quantitatively the relation between airflow velocity and pressure loss coefficient in subjects with and without nasal obstruction.We conducted an observational cross-sectional study of 16 Japanese adult subjects, of whom 9 had nasal obstruction and 7 did not (control group. Three-dimensional reconstructed models of the nasal cavity and nasopharynx with a CPAP mask fitted to the nostrils were created from each subject's CT scans. The digital models were meshed with tetrahedral cells and stereolithography formats were created. CPAP airflow simulations were conducted using CFD software. Airflow streamlines and velocity contours in the nasal cavities and nasopharynx were compared between groups. Simulation models were confirmed to agree with actual measurements of nasal flow rate and with pressure and flow rate in the CPAP machine.Under 10 cmH2O CPAP, average maximum airflow velocity during inspiration was 17.6 ± 5.6 m/s in the nasal obstruction group but only 11.8 ± 1.4 m/s in the control group. The average pressure drop in the nasopharynx relative to inlet static pressure was 2.44 ± 1.41 cmH2O in the nasal obstruction group but only 1.17 ± 0.29 cmH2O in the control group. The nasal obstruction and control groups were clearly separated by a velocity threshold of 13.5 m/s, and pressure loss coefficient threshold of approximately 10.0. In contrast, there was no significant difference in expiratory pressure in the nasopharynx between the groups.This is the first CFD analysis of the effect of nasal obstruction on CPAP treatment. A strong correlation between the inspiratory pressure loss coefficient and maximum airflow velocity was found.

  8. Irrigation dynamics associated with positive pressure, apical negative pressure and passive ultrasonic irrigations: a computational fluid dynamics analysis.

    Science.gov (United States)

    Chen, José Enrique; Nurbakhsh, Babak; Layton, Gillian; Bussmann, Markus; Kishen, Anil

    2014-08-01

    Complexities in root canal anatomy and surface adherent biofilm structures remain as challenges in endodontic disinfection. The ability of an irrigant to penetrate into the apical region of a canal, along with its interaction with the root canal walls, will aid in endodontic disinfection. The aim of this study was to qualitatively examine the irrigation dynamics of syringe irrigation with different needle tip designs (open-ended and closed-ended), apical negative pressure irrigation with the EndoVac® system, and passive ultrasonic-assisted irrigation, using a computational fluid dynamics model. Syringe-based irrigation with a side-vented needle showed a higher wall shear stress than the open-ended but was localised to a small region of the canal wall. The apical negative pressure mode of irrigation generated the lowest wall shear stress, while the passive-ultrasonic irrigation group showed the highest wall shear stress along with the greatest magnitude of velocity.

  9. DYNAMIC ANALYSIS OF TWO-DEGREE-OF-FREEDOM OBLIQUE IMPACT SYSTEM WITH NON-FIXED IMPACT POSITIONS

    Institute of Scientific and Technical Information of China (English)

    JIN Li; LU Qi-shao; WANG Qi

    2005-01-01

    The dynamic behavior of a two-degree-of-freedom oblique impact system consisted of two pendulums with non-fixed impact positions is investigated. The relations between the restitution coefficient, the friction coefficient, as well as other parameters of the system and the states before or after impact, are clarified in this oblique impact process. The existence criterion of single impact periodic-n subharmonic motions is deduced based on the Poincare map method and the oblique impact relations with non-fixed impact positions. The stability of these subharmonic periodic motions is analyzed by the Floquet theory, and the formulas to calculate the Floquet multipliers are given. The validity of this method is shown through numerical simulation. At the same time, the probability distribution of impact positions in this oblique system with nonfixed impact positions is analyzed.

  10. Can positional MRI predict dynamic changes in the medial plantar arch?

    DEFF Research Database (Denmark)

    Johannsen, Finn; Hansen, Philip; Stallknecht, Sandra;

    2016-01-01

    and c) standing position with addition of 10 % body weight during static loading of the foot. Stretch sensor measurements were also performed during barefoot walking. RESULTS: The total change in navicular position measured by pMRI was 10.3 mm (CI: 7.0 to 13.5 mm). No further displacement occurred when...

  11. In vivo dynamics of GFRα1-positive spermatogonia stimulated by GDNF signals using a bead transplantation assay

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Aya; Kishi, Kasane; Aiyama, Yoshimi; Miura, Kento [Department of Veterinary Anatomy, The University of Tokyo, Yayoi, Tokyo, 113-8657 (Japan); Takase, Hinako M.; Suzuki, Hitomi; Kanai-Azuma, Masami [Department of Experimental Animal Model for Human Disease, Tokyo Medical and Dental University, Tokyo, 113-8510 (Japan); Iwamori, Tokuko [Center of Biomedical Research, Kyusyu University, Fukuoka, 812-8582 (Japan); Kurohmaru, Masamichi; Tsunekawa, Naoki [Department of Veterinary Anatomy, The University of Tokyo, Yayoi, Tokyo, 113-8657 (Japan); Kanai, Yoshiakira, E-mail: aykanai@mail.ecc.u-tokyo.ac.jp [Department of Veterinary Anatomy, The University of Tokyo, Yayoi, Tokyo, 113-8657 (Japan)

    2016-08-05

    In mouse testes, spermatogonial stem cells (SSCs), a subpopulation of GFRα1 (GDNF family receptor-α1)-positive spermatogonia, are widely distributed along the convoluted seminiferous tubules. The proliferation and differentiation of the SSCs are regulated in part by local expression of GDNF (glial cell-derived neurotorphic factor), one of major niche factors for SSCs. However, the in vivo dynamics of the GDNF-stimulated GFRα1-positive spermatogonia remains unclear. Here, we developed a simple method for transplanting DiI-labeled and GDNF-soaked beads into the mouse testicular interstitium. By using this method, we examined the dynamics of GFRα1-positive spermatogonia in the tubular walls close to the transplanted GDNF-soaked beads. The bead-derived GDNF signals were able to induce the stratified aggregate formation of GFRα1-positive undifferentiated spermatogonia by day 3 post-transplantation. Each aggregate consisted of tightly compacted A{sub single} and marginal A{sub paired}–A{sub aligned} GFRα1-positive spermatogonia and was surrounded by A{sub aligned} GFRα1-negative spermatogonia at more advanced stages. These data not only provide in vivo evidence for the inductive roles of GDNF in forming a rapid aggregation of GFRα1-positive spermatogonia but also indicate the usefulness of this in vivo assay system of various growth factors for the stem/progenitor spermatogonia in mammalian spermatogenesis. - Highlights: • A novel bead transplantation assay was developed to examine the in vivo effects of growth factors on spermatogonia. • A rapid aggregation of GFRα1-positive spermatogonia was induced by the transplanted GDNF-soaked beads. • Tightly-compacted A{sub single} and marginal A{sub paired}–A{sub aligned} spermatogonia were formed in each GFRα1-positive aggregate.

  12. Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

    Directory of Open Access Journals (Sweden)

    Dongkai Shen

    2016-01-01

    Full Text Available In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics.

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

    Science.gov (United States)

    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. We 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. 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.

  14. Continuous positive airway pressure alters cranial blood flow and cerebrospinal fluid dynamics at the craniovertebral junction

    Directory of Open Access Journals (Sweden)

    Theresia I. Yiallourou

    2015-09-01

    Conclusion: Application of CPAP via a full-fitted mask at 15 cm H2O was found to have a significant effect on intracranial venous outflow and spinal CSF flow at the C2 vertebral level in healthy adult-age awake volunteers. CPAP can be used to non-invasively provoke changes in intracranial and CSF flow dynamics.

  15. Analysis of the effect of swimmer's head position on swimming performance using computational fluid dynamics.

    Science.gov (United States)

    Zaïdi, H; Taïar, R; Fohanno, S; Polidori, G

    2008-01-01

    The aim of this numerical work is to analyze the effect of the position of the swimmer's head on the hydrodynamic performances in swimming. In this initial study, the problem was modeled as 2D and in steady hydrodynamic state. The geometry is generated by the CAD software CATIA and the numerical simulation is carried out by the use of the CFD Fluent code. The standard k-epsilon turbulence model is used with a specific wall law. Three positions of the head were studied, for a range of Reynolds numbers about 10(6). The obtained numerical results revealed that the position of the head had a noticeable effect on the hydrodynamic performances, strongly modifying the wake around the swimmer. The analysis of these results made it possible to propose an optimal position of the head of a swimmer in underwater swimming.

  16. Towards a naturalistic brain-machine interface: hybrid torque and position control allows generalization to novel dynamics.

    Directory of Open Access Journals (Sweden)

    Pratik Y Chhatbar

    Full Text Available Realization of reaching and grasping movements by a paralytic person or an amputee would greatly facilitate her/his activities of daily living. Towards this goal, control of a computer cursor or robotic arm using neural signals has been demonstrated in rodents, non-human primates and humans. This technology is commonly referred to as a Brain-Machine Interface (BMI and is achieved by predictions of kinematic parameters, e.g. position or velocity. However, execution of natural movements, such as swinging baseball bats of different weights at the same speed, requires advanced planning for necessary context-specific forces in addition to kinematic control. Here we show, for the first time, the control of a virtual arm with representative inertial parameters using real-time neural control of torques in non-human primates (M. radiata. We found that neural control of torques leads to ballistic, possibly more naturalistic movements than position control alone, and that adding the influence of position in a hybrid torque-position control changes the feedforward behavior of these BMI movements. In addition, this level of control was achievable utilizing the neural recordings from either contralateral or ipsilateral M1. We also observed changed behavior of hybrid torque-position control under novel external dynamic environments that was comparable to natural movements. Our results demonstrate that inclusion of torque control to drive a neuroprosthetic device gives the user a more direct handle on the movement execution, especially when dealing with novel or changing dynamic environments. We anticipate our results to be a starting point of more sophisticated algorithms for sensorimotor neuroprostheses, eliminating the need of fully automatic kinematic-to-dynamic transformations as currently used by traditional kinematic-based decoders. Thus, we propose that direct control of torques, or other force related variables, should allow for more natural

  17. Reliability and reference values of two clinical measurements of dynamic and static knee position in healthy children

    DEFF Research Database (Denmark)

    Ortqvist, Maria; Moström, Eva B; Roos, Ewa M.

    2011-01-01

    PURPOSE: The purposes of this study were to evaluate reliability of the Single-limb mini squat test (a dynamic measure of medio-lateral knee position) and the Quadriceps-angle (Q-angle) (a static measure of medio-lateral knee position), present paediatric reference values of the Q......-angle, and evaluate the association between the tests. METHODS: Two hundred and forty-six healthy children (9-16 years) were included (intra/inter-rater reliability for Q-angle (n = 37/85) and for Single-limb mini squat test (n = 33/28)). Dynamic medio-lateral knee position was assessed by the Single-limb mini squat...... test. Static medio-lateral knee position was evaluated by the Q-angle. RESULTS: The reliability of the Single-limb mini squat test was found to be moderate (kappa 0.48-0.57, 95% CI 0.16-0.85, 76-79% agreement). Fair to moderate reliability (ICC 0.35-0.42, 95% CI 0.11-0.66, SEM 1.4°-1.9°, n.s.) of the Q...

  18. Digital Video Broadcast-Terrestrial (DVB-T) single frequency networks positioning in dynamic scenarios.

    Science.gov (United States)

    Huang, Jie; Lo Presti, Letizia; Garello, Roberto

    2013-08-09

    Since Global Navigation Satellite Systems (GNSS) show degraded performance in dense urban and indoor areas, a positioning sensor based on Digital Video Broadcast-Terrestrial (DVB-T) systems is presented in this paper. DVB-T signals can be considered as signals-of-opportunity for positioning, due to their good properties. One of the challenges to overcome is to distinguish the signals from different emitters. Here, we suppose that the user can first compute his position by GNSS during an initialization phase, which is used for solving all the ambiguities concerning DVB-T emitters. Starting from there, DVB-T signals can be used for aiding positioning when the user enters a GNSS-blocked area, up to a limit case, where all the GNSS satellites are not in view and only DVB-T signals are used for positioning. We tested this method by simulation, by adopting the Hata model for the emitter attenuations and the Rayleigh model for multipath. The obtained results show good performance if the receiver correctly associates the signal to the user's motion.

  19. Digital Video Broadcast-Terrestrial (DVB-T Single Frequency Networks Positioning in Dynamic Scenarios

    Directory of Open Access Journals (Sweden)

    Letizia Lo Presti

    2013-08-01

    Full Text Available Since Global Navigation Satellite Systems (GNSS show degraded performance in dense urban and indoor areas, a positioning sensor based on Digital Video Broadcast-Terrestrial (DVB-T systems is presented in this paper. DVB-T signals can be considered as signals-of-opportunity for positioning, due to their good properties. One of the challenges to overcome is to distinguish the signals from different emitters. Here, we suppose that the user can first compute his position by GNSS during an initialization phase, which is used for solving all the ambiguities concerning DVB-T emitters. Starting from there, DVB-T signals can be used for aiding positioning when the user enters a GNSS-blocked area, up to a limit case, where all the GNSS satellites are not in view and only DVB-T signals are used for positioning. We tested this method by simulation, by adopting the Hata model for the emitter attenuations and the Rayleigh model for multipath. The obtained results show good performance if the receiver correctly associates the signal to the user’s motion.

  20. Optical Pulse Dynamics in Active Metamaterials with Positive and Negative Refractive Index

    CERN Document Server

    Korotkevich, Alexander O; Kovacic, Gregor; Roytburd, Victor; Maimistov, Andrei I; Gabitov, Ildar R; .,

    2013-01-01

    We study numerically the propagation of two-color light pulses through a metamaterial doped with active atoms such that the carrier frequencies of the pulses are in resonance with two atomic transitions in the $\\Lambda$ configuration and that one color propagates in the regime of positive refraction and the other in the regime of negative refraction. In such a metamaterial, one resonant color of light propagates with positive and the other with negative group velocity. We investigate nonlinear interaction of these forward- and backward-propagating waves, and find self-trapped waves, counter-propagating radiation waves, and hot spots of medium excitation.

  1. Systematic comparison of position and time dependent macroparticle simulations in beam dynamics studies

    Directory of Open Access Journals (Sweden)

    Ji Qiang

    2002-06-01

    Full Text Available Macroparticle simulation plays an important role in modern accelerator design and operation. Most linear rf accelerators have been designed based on macroparticle simulations using longitudinal position as the independent variable. In this paper, we have done a systematic comparison between using longitudinal position as the independent variable and using time as the independent variable in macroparticle simulations. We have found that, for an rms-matched beam, the maximum relative moment difference for second, fourth moments and beam maximum amplitudes between these two types of simulations is 0.25% in a 10 m reference transport system with physical parameters similar to the Spallation Neutron Source linac design. The maximum z-to- t transform error in the space-charge force calculation of the position dependent simulation is about 0.1% in such a system. This might cause a several percent error in a complete simulation of a linac with a length of hundreds of meters. Furthermore, the error may be several times larger in simulations of mismatched beams. However, if such errors are acceptable to the linac designer, then one is justified in using position dependent macroparticle simulations in this type of linac design application.

  2. Bloodstain Pattern Analysis: implementation of a fluid dynamic model for position determination of victims

    NARCIS (Netherlands)

    N. Laan; K.G. de Bruin; D. Slenter; J. Wilhelm; M. Jermy; D. Bonn

    2015-01-01

    Bloodstain Pattern Analysis is a forensic discipline in which, among others, the position of victims can be determined at crime scenes on which blood has been shed. To determine where the blood source was investigators use a straight-line approximation for the trajectory, ignoring effects of gravity

  3. Empathy Is Associated with Dynamic Change in Prefrontal Brain Electrical Activity during Positive Emotion in Children

    Science.gov (United States)

    Light, Sharee N.; Coan, James A.; Zahn-Waxler, Carolyn; Frye, Corrina; Goldsmith, H. Hill; Davidson, Richard J.

    2009-01-01

    Empathy is the combined ability to interpret the emotional states of others and experience resultant, related emotions. The relation between prefrontal electroencephalographic asymmetry and emotion in children is well known. The association between positive emotion (assessed via parent report), empathy (measured via observation), and…

  4. A dynamic programming algorithm for the space allocation and aisle positioning problem

    DEFF Research Database (Denmark)

    Bodnar, Peter; Lysgaard, Jens

    2014-01-01

    The space allocation and aisle positioning problem (SAAPP) in a material handling system with gravity flow racks is the problem of minimizing the total number of replenishments over a period subject to practical constraints related to the need for aisles granting safe and easy access to storage l...

  5. Recognition of Prior Learning (RPL) Policy in Australian Higher Education: The Dynamics of Position-Taking

    Science.gov (United States)

    Pitman, Tim; Vidovich, Lesley

    2012-01-01

    The Bourdieuian concept of "position-taking" is applied in this analysis of recognition of prior learning (RPL) policy and practice in Australian higher education. Data from institutional documents and participant interviews indicate that, within RPL policy, the universities selectively employ prevailing discourses of "quality"…

  6. Resilience in Change: Positive Perspectives on the Dynamics of Change in Early Childhood Systems

    Science.gov (United States)

    Douglass, Anne

    2016-01-01

    Change is a central feature of the early care and education landscape today. Much of the research on educational change focuses on the negative or challenging aspects of change. This study employed a critical theory framework from the organizational sciences field, positive organizational scholarship, to offer a new way of thinking about change in…

  7. Reliability-based dynamic positioning of floating vessels with riser and mooring system

    DEFF Research Database (Denmark)

    Fang, Shaoji; Leira, Bernt J.; Blanke, Mogens

    2011-01-01

    To maintain safety of a floating vessel with associated slender components such as risers and mooring line, the vessel is normally kept within a limited region. To specify a safe position in that region, this paper suggests a new position chasing algorithm with the consideration of both riser...... angles and mooring line tensions. The riser angles were considered in an object function in [1] and the mooring line tension was considered in an object function in [2]. The contribution of this paper is to combine riser angle and mooring line tension together in one unified object function....... A combination of scaled riser angles and structural reliability index is utilized to evaluate the “reserve capacity” relative to failure events. With this object function, the riser angles and mooring line tension are considered in a unified formulation, with higher weight added to the riser angles due...

  8. Use of dynamic CT in acute respiratory distress syndrome (ARDS) with comparison of positive and negative pressure ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Helm, Emma; Babyn, Paul [Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Talakoub, Omid; Alirezaie, Javad [Ryerson University, Department of Electrical and Computer Engineering, Toronto, ON (Canada); Grasso, Francesco; Engelberts, Doreen; Kavanagh, Brian P. [Hospital for Sick Children and the University of Toronto, Departments of Anesthesia and Critical Care Medicine and the Program in Pulmonary and Experimental Medicine, Toronto (Canada)

    2009-01-15

    Negative pressure ventilation via an external device ('iron lung') has the potential to provide better oxygenation with reduced barotrauma in patients with ARDS. This study was designed to see if oxygenation differences between positive and negative ventilation could be explained by CT. Six anaesthetized rabbits had ARDS induced by repeated saline lavage. Rabbits were ventilated with positive pressure ventilation (PPV) and negative pressure ventilation (NPV) in turn. Dynamic CT images were acquired over the respiratory cycle. A computer-aided method was used to segment the lung and calculate the range of CT densities within each slice. Volumes of ventilated lung and atelectatic lung were measured over the respiratory cycle. NPV was associated with an increased percentage of ventilated lung and decreased percentage of atelectatic lung. The most significant differences in ventilation and atelectasis were seen at mid-inspiration and mid-expiration (ventilated lung NPV=61%, ventilated lung PPV=47%, p<0.001; atelectatic lung NPV=10%, atelectatic lung PPV 19%, p<0.001). Aeration differences were not significant at end-inspiration. Dynamic CT can show differences in lung aeration between positive and negative ventilation in ARDS. These differences would not be appreciated if only static breath-hold CT was used. (orig.)

  9. Dynamic obstacle avoidance with a prototype mobile robot using acoustic, infrared and position sensing

    OpenAIRE

    Kurbay, Saner

    1997-01-01

    Ankara : Department of Electrical and Electronics Engineering and Institute of Engineering and Sciences, Bilkent Univ., 1997. Thesis (Master's) -- Bilkent University, 1997. Includes bibliographical references leaves 328-330 In this study, a small mobile robot is designed and built which employs infrared and acoustic sensors for detecting obstacles in the environment and a computer mouse for position sensing* that is installed underneath the robot. The robot is suitably desig...

  10. Mapping 'consistency' in India's climate change position: Dynamics and dilemmas of science diplomacy.

    Science.gov (United States)

    Gupta, Himangana; Kohli, Ravinder Kumar; Ahluwalia, Amrik Singh

    2015-10-01

    India's position on climate change negotiations is likely to have far reaching implications for the success of global climate cooperation. Since the beginning of negotiations, the principle of equity and common but differentiated responsibilities (CBDR) remained the centerpiece of India's stand. The stand started to evolve at the 15th Conference of Parties to the United Nations Framework Convention on Climate Change at Copenhagen in 2009, when India accepted voluntary commitments to reduce emission intensity. Though India still swears by CBDR, status of the principle in the negotiations has become doubtful after the Durban Climate Conference in 2011 committed all parties to take emission targets. This paper traces major transition points in India's negotiating position over the years and provides a descriptive context of its climate-related concerns. It analyzes the interview responses of 15 top scientists, experts, and negotiators to build upon core areas of climate change issues in India, its future role, and position in negotiations. Interviewees, in general, were in favor of protecting the carbon space for the poor who had very low emissions.

  11. Transient flickering behavior in fringe-field switching liquid crystal mode analyzed by positional asymmetric flexoelectric dynamics.

    Science.gov (United States)

    Lee, Dong-Jin; Shim, Gyu-Yeop; Choi, Jun-Chan; Park, Ji-Sub; Lee, Joun-Ho; Baek, Ji-Ho; Choi, Hyun Chul; Ha, Yong Min; Ranjkesh, Amid; Kim, Hak-Rin

    2015-12-28

    We analyzed a transient blinking phenomenon in a fringe-field switching liquid crystal (LC) mode that occurred at the moment of frame change even in the optimized DC offset condition for minimum image flicker. Based on the positional dynamic behaviors of LCs by using a high-speed camera, we found that the transient blink is highly related to the asymmetric responses of the splay-bend transitions caused by the flexoelectric (FE) effect. To remove the transient blink, the elastic property adjustment of LCs was an effective solution because the FE switching dynamics between the splay-enhanced and bend-enhanced deformations are highly dependent on the elastic constants of LCs, which is the cause of momentary brightness drop.

  12. Evaluation of MLC leaf positioning accuracy for static and dynamic IMRT treatments using DAVID in vivo dosimetric system.

    Science.gov (United States)

    Karagoz, Gulay; Zorlu, Faruk; Yeginer, Mete; Yildiz, Demet; Ozyigit, Gokhan

    2016-03-08

    Accuracy and precision of leaf positioning in multileaf collimators (MLCs) are significant factors for the accuracy of IMRT treatments. This study aimed to inves-tigate the accuracy and repeatability of the MLC leaf positioning via the DAVID invivo dosimetric system for dynamic and static MLC systems. The DAVID system was designed as multiwire transmission ionization chamber which is placed in accessory holder of linear accelerators. Each wire of DAVID system corresponds to a MLC leaf-pair to verify the leaf positioning accuracy during IMRT treatment and QA. In this study, verifications of IMRT plans of five head and neck (H&N) and five prostate patients treated in a Varian DHX linear accelerator with 80-leaf MLC were performed using DAVID system. Before DAVID-based dosimetry, Electronics Portal Imaging Device (EPID) and PTW 2D ARRAY dosimetry system were used for 2D verification of each plan. The measurements taken by DAVID system in the first day of the treatments were used as reference for the following measurements taken over the next four weeks. The deviations in leaf positioning were evaluated by "Total Deviation (TD)" parameter calculated by DAVID software. The delivered IMRT plans were originally prepared using dynamic MLC method. The same plans were subsequently calculated based on static MLC method with three different intensity levels of five (IL5), 10 (IL10) and 20 (IL20) in order to compare the performances of MLC leaf positioning repeatability for dynamic and static IMRT plans. The leaf positioning accuracy is also evaluated by analyzing DynaLog files based on error histograms and root mean square (RMS) errors of leaf pairs' positions. Moreover, a correlation analysis between simultaneously taken DAVID and EPID measurements and DynaLog file recordings was subsequently performed. In the analysis of DAVID outputs, the overall deviations of dynamic MLC-based IMRT calculated from the deviations of the four weeks were found as 0.55% ± 0.57% and 1.48% ± 0

  13. Virtual Reality Simulation of Fuzzy-logic Control during Underwater Dynamic Positioning

    Institute of Scientific and Technical Information of China (English)

    Midhin Das Thekkedan; Cheng Siong Chin; Wai Lok Woo

    2015-01-01

    In this paper, graphical-user-interface (GUI) software for simulation and fuzzy-logic control of a remotely operated vehicle (ROV) using MATLABTM GUI Designing Environment is proposed. The proposed ROV’s GUI platform allows the controller such as fuzzy-logic control systems design to be compared with other controllers such as proportional-integral-derivative (PID) and sliding-mode controller (SMC) systematically and interactively. External disturbance such as sea current can be added to improve the modelling in actual underwater environment. The simulated results showed the position responses of the fuzzy-logic control exhibit reasonable performance under the sea current disturbance.

  14. Virtual reality simulation of fuzzy-logic control during underwater dynamic positioning

    Science.gov (United States)

    Thekkedan, Midhin Das; Chin, Cheng Siong; Woo, Wai Lok

    2015-03-01

    In this paper, graphical-user-interface (GUI) software for simulation and fuzzy-logic control of a remotely operated vehicle (ROV) using MATLAB™ GUI Designing Environment is proposed. The proposed ROV's GUI platform allows the controller such as fuzzy-logic control systems design to be compared with other controllers such as proportional-integral-derivative (PID) and sliding-mode controller (SMC) systematically and interactively. External disturbance such as sea current can be added to improve the modelling in actual underwater environment. The simulated results showed the position responses of the fuzzy-logic control exhibit reasonable performance under the sea current disturbance.

  15. Constrained Control Design for Dynamic Positioning of Marine Vehicles with Control Allocation

    Directory of Open Access Journals (Sweden)

    Tristan Perez

    2009-04-01

    Full Text Available In this paper, we address the control design problem of positioning of over-actuated marine vehicles with control allocation. The proposed design is based on a combined position and velocity loops in a multi-variable anti-windup implementation together with a control allocation mapping. The vehicle modelling is considered with appropriate simplifications related to low-speed manoeuvring hydrodynamics and vehicle symmetry. The control design is considered together with a control allocation mapping. We derive analytical tuning rules based on requirements of closed-loop stability and performance. The anti- windup implementation of the controller is obtained by mapping the actuator-force constraint set into a constraint set for the generalized forces. This approach ensures that actuation capacity is not violated by constraining the generalized control forces; thus, the control allocation is simplified since it can be formulated as an unconstrained problem. The mapping can also be modified on-line based on actuator availability to provide actuator-failure accommodation. We provide a proof of the closed-loop stability and illustrate the performance using simulation scenarios for an open-frame underwater vehicle.

  16. Learning effect on the dynamical strategies in sitting position on seesaw motion for idiopathic scoliosis patients.

    Science.gov (United States)

    Bruyneel, Anne-Violette; Mesure, Serge

    2013-02-01

    Our study meant to determine, for idiopathic scoliosis patients, the biomechanical processes involved in postural regulation when self-imposed disturbances occur in seated position in both directions during successive trials. 12 female adolescents with right thoracic scoliosis (SG) and 15 control adolescents (CG) were included in this study. Ground reaction forces were studied using a force platform while the subjects were maintaining their balance in sitting position on a seesaw. Every test is recorded with eyes opened, arms on shoulders and legs free. The force platform data (AP and ML forces data) obtained were processed to determine the following normalized force parameters: delta value (difference between maxima and minima), maximal and minimal force values (peak and occurrence), and the variability of AP and ML forces. We used a variance analysis (ANOVA test) to analyze and compare 3 trials and groups. Our results show that, whatever the directions of destabilization (AP versus ML), SG was always in a learning situation. Indeed, the first test is always less stable than the second and third trials. However, for CG, adaptability between the tests is only highlighted during ML imbalance. Significant differences of strategies between the groups are only visible for the AP force component. For all conditions imposed, scoliotic patients perform specific trunk balance strategies. Clinical tests and rehabilitation methods should include the learning effect within the spatio-temporal adaptation to ground reaction forces.

  17. Numerical simulation of magnetospheric ULF waves excited by positive and negative impulses of solar wind dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The sources of ultra low frequency (ULF) waves in the magnetosphere are generally believed to be either the external solar wind perturbations or the internal plasma instabilities. When a sudden impulse of the solar wind dynamic pressure impinges on the magnetopause, ULF waves might be excited and thus the solar wind energy is transported into the earth’s magnetosphere. In this paper, we study the ULF waves excited by different kinds of sudden solar wind pressure impulses through an MHD simulation. We primarily focus on the responses of the earth’s magnetosphere to positive/negative impulses of solar wind dynamic pressure, and positive-negative impulse pairs. The simulation results show that the ULF waves excited by positive and negative impulse have the same amplitude and frequency, with 180° difference in phase, if the amplitude and durations of the input impulses are the same. In addition, it is found that field line resonances (FLRs) occur at certain L-shell regions of the earth’s magneto-sphere after the impact of different positive-negative impulse pairs, which appear to be related to the duration of the impulses and the time interval between the sequential impulses. Another result is that the energy from the solar wind could be transported deeper into the inner magnetosphere by an impulse pair than by a single pulse impact. The results presented in this paper could help us to better understand how energy is transported from solar wind to the earth’s magnetosphere via ULF waves. Also, these results provide some new clues to understanding of how energetic particles in the inner magnetosphere response to different kinds of solar wind pressure impulse impacts including inter-planetary shocks.

  18. Prolonged perceptual learning of positional acuity in adult amblyopia: perceptual template retuning dynamics.

    Science.gov (United States)

    Li, Roger W; Klein, Stanley A; Levi, Dennis M

    2008-12-24

    Amblyopia is a developmental abnormality that results in physiological alterations in the visual cortex and impairs form vision. It is often successfully treated by patching the sound eye in infants and young children, but is generally considered to be untreatable in adults. However, a number of recent studies suggest that repetitive practice of a visual task using the amblyopic eye results in improved performance in both children and adults with amblyopia. These perceptual learning studies have used relatively brief periods of practice; however, clinical studies have shown that the time-constant for successful patching is long. The time-constant for perceptual learning in amblyopia is still unknown. Here we show that the time-constant for perceptual learning depends on the degree of amblyopia. Severe amblyopia requires >50 h (approximately equal to 35,000 trials) to reach plateau, yielding as much as a five-fold improvement in performance at a rate of approximately equal to 1.5%/h. There is significant transfer of learning from the amblyopic to the dominant eye, suggesting that the learning reflects alterations in higher decision stages of processing. Using a reverse correlation technique, we document, for the first time, a dynamic retuning of the amblyopic perceptual decision template and a substantial reduction in internal spatial distortion. These results show that the mature amblyopic brain is surprisingly malleable, and point to more intensive treatment methods for amblyopia.

  19. Nanoscale soldering of axially positioned single-walled carbon nanotubes: a molecular dynamics simulation study.

    Science.gov (United States)

    Cui, Jianlei; Yang, Lijun; Zhou, Liang; Wang, Yang

    2014-02-12

    The miniaturization of electronics devices into the nanometer scale is indispensable for next-generation semi-conductor technology. Carbon nanotubes (CNTs) are considered to be the promising candidates for future interconnection wires. To study the carbon nanotubes interconnection during nanosoldering, the melting process of nanosolder and nanosoldering process between single-walled carbon nanotubes are simulated with molecular dynamics method. As the simulation results, the melting point of 2 nm silver solder is about 605 K because of high surface energy, which is below the melting temperature of Ag bulk material. In the nanosoldering process simulations, Ag atoms may be dragged into the nanotubes to form different connection configuration, which has no apparent relationship with chirality of SWNTs. The length of core filling nanowires structure has the relationship with the diameter, and it does not become longer with the increasing diameter of SWNT. Subsequently, the dominant mechanism of was analyzed. In addition, as the heating temperature and time, respectively, increases, more Ag atoms can enter the SWNTs with longer length of Ag nanowires. And because of the strong metal bonds, less Ag atoms can remain with the tight atomic structures in the gap between SWNT and SWNT. The preferred interconnection configurations can be achieved between SWNT and SWNT in this paper.

  20. Dynamic assignment and maintenance of positional identity in the ventral neural tube by the morphogen sonic hedgehog.

    Directory of Open Access Journals (Sweden)

    Eric Dessaud

    Full Text Available Morphogens are secreted signalling molecules that act in a graded manner to control the pattern of cellular differentiation in developing tissues. An example is Sonic hedgehog (Shh, which acts in several developing vertebrate tissues, including the central nervous system, to provide positional information during embryonic patterning. Here we address how Shh signalling assigns the positional identities of distinct neuronal subtype progenitors throughout the ventral neural tube. Assays of intracellular signal transduction and gene expression indicate that the duration as well as level of signalling is critical for morphogen interpretation. Progenitors of the ventral neuronal subtypes are established sequentially, with progressively more ventral identities requiring correspondingly higher levels and longer periods of Shh signalling. Moreover, cells remain sensitive to changes in Shh signalling for an extended time, reverting to antecedent identities if signalling levels fall below a threshold. Thus, the duration of signalling is important not only for the assignment but also for the refinement and maintenance of positional identity. Together the data suggest a dynamic model for ventral neural tube patterning in which positional information corresponds to the time integral of Shh signalling. This suggests an alternative to conventional models of morphogen action that rely solely on the level of signalling.

  1. Computational fluid dynamics analysis of drag and convective heat transfer of individual body segments for different cyclist positions.

    Science.gov (United States)

    Defraeye, Thijs; Blocken, Bert; Koninckx, Erwin; Hespel, Peter; Carmeliet, Jan

    2011-06-03

    This study aims at investigating drag and convective heat transfer for cyclists at a high spatial resolution. Such an increased spatial resolution, when combined with flow-field data, can increase insight in drag reduction mechanisms and in the thermo-physiological response of cyclists related to heat stress and hygrothermal performance of clothing. Computational fluid dynamics (steady Reynolds-averaged Navier-Stokes) is used to evaluate the drag and convective heat transfer of 19 body segments of a cyclist for three different cyclist positions. The influence of wind speed on the drag is analysed, indicating a pronounced Reynolds number dependency on the drag, where more streamlined positions show a dependency up to higher Reynolds numbers. The drag and convective heat transfer coefficient (CHTC) of the body segments and the entire cyclist are compared for all positions at racing speeds, showing high drag values for the head, legs and arms and high CHTCs for the legs, arms, hands and feet. The drag areas of individual body segments differ markedly for different cyclist positions whereas the convective heat losses of the body segments are found to be less sensitive to the position. CHTC-wind speed correlations are derived, in which the power-law exponent does not differ significantly for the individual body segments for all positions, where an average value of 0.84 is found. Similar CFD studies can be performed to assess drag and CHTCs at a higher spatial resolution for applications in other sport disciplines, bicycle equipment design or to assess convective moisture transfer.

  2. Accelerated molecular dynamics simulations of the octopamine receptor using GPUs: discovery of an alternate agonist-binding position.

    Science.gov (United States)

    Kastner, Kevin W; Izaguirre, Jesús A

    2016-10-01

    Octopamine receptors (OARs) perform key biological functions in invertebrates, making this class of G-protein coupled receptors (GPCRs) worth considering for insecticide development. However, no crystal structures and very little research exists for OARs. Furthermore, GPCRs are large proteins, are suspended in a lipid bilayer, and are activated on the millisecond timescale, all of which make conventional molecular dynamics (MD) simulations infeasible, even if run on large supercomputers. However, accelerated Molecular Dynamics (aMD) simulations can reduce this timescale to even hundreds of nanoseconds, while running the simulations on graphics processing units (GPUs) would enable even small clusters of GPUs to have processing power equivalent to hundreds of CPUs. Our results show that aMD simulations run on GPUs can successfully obtain the active and inactive state conformations of a GPCR on this reduced timescale. Furthermore, we discovered a potential alternate active-state agonist-binding position in the octopamine receptor which has yet to be observed and may be a novel GPCR agonist-binding position. These results demonstrate that a complex biological system with an activation process on the millisecond timescale can be successfully simulated on the nanosecond timescale using a simple computing system consisting of a small number of GPUs. Proteins 2016; 84:1480-1489. © 2016 Wiley Periodicals, Inc.

  3. Dynamic Measurements of the Position, Orientation, and DNA Content of Individual Unlabeled Bacteriophages.

    Science.gov (United States)

    Goldfain, Aaron M; Garmann, Rees F; Jin, Yan; Lahini, Yoav; Manoharan, Vinothan N

    2016-07-01

    A complete understanding of the cellular pathways involved in viral infections will ultimately require a diverse arsenal of experimental techniques, including methods for tracking individual viruses and their interactions with the host. Here we demonstrate the use of holographic microscopy to track the position, orientation, and DNA content of unlabeled bacteriophages (phages) in solution near a planar, functionalized glass surface. We simultaneously track over 100 individual λ phages at a rate of 100 Hz across a 33 μm × 33 μm portion of the surface. The technique determines the in-plane motion of the phage to nanometer precision, and the height of the phage above the surface to 100 nm precision. Additionally, we track the DNA content of individual phages as they eject their genome following the addition of detergent-solubilized LamB receptor. The technique determines the fraction of DNA remaining in the phage to within 10% of the total 48.5 kilobase pairs. Analysis of the data reveals that under certain conditions, λ phages move along the surface with their heads down and intermittently stick to the surface by their tails, causing them to stand up. Furthermore, we find that in buffer containing high concentrations of both monovalent and divalent salts, λ phages eject their entire DNA in about 7 s. Taken together, these measurements highlight the potential of holographic microscopy to resolve the fast kinetics of the early stages of phage infection.

  4. Evaluation of the Circulatory Dynamics by using the Windkessel Model in Different Body Positions

    Science.gov (United States)

    Kotani, Kiyoshi; Iida, Fumiaki; Ogawa, Yutaro; Takamasu, Kiyoshi; Jimbo, Yasuhiko

    Autonomic nervous system is important in maintaining homeostasis by the opposing effects of sympathetic and parasympathetic nervous activity on organs. However, it is known that they are at times simultaneously increased or decreased in cases of strong fear or depression. Therefore, it is required to evaluate sympathetic and parasympathetic nervous activity independently. In this paper, we propose a method to evaluate sympathetic nervous activity by analyzing the decreases in blood pressure by utilizing the Windkessel model. Experiments are performed in sitting and standing positions for 380 s, respectively. First, we evaluate the effects of length for analysis on the Windkessel time constant. We shorten the length for analysis by multiplying constant coefficients (1.0, 0.9, and 0.8) to the length of blood pressure decrease and then cut-out the waveform for analysis. Then it is found that the Windkessel time constant is decreased as the length for analysis is shortened. This indicates that the length for analysis should be matched when the different experiments are compared. Second, we compare the Windkessel time constant of sitting to that of standing by matching their length for analysis. With statistically significant difference (Pnervous activity on vascular smooth muscle.

  5. The relation of gingival thickness to dynamics of gingival margin position pre- and post-surgically

    Directory of Open Access Journals (Sweden)

    Kharidhi Laxman Vandana

    2016-01-01

    Full Text Available Background: To evaluate the gingival margin position (GMP before and after open flap debridement in different gingival thickness (GT. Materials and Methods: Twenty-seven healthy patients with moderate to advanced adult periodontitis were included in a randomized control clinical trial. A calibrated UNC-15 periodontal probe, an occlusal onlay stent was used for clinical measurements recorded at baseline, 3 month, 6 month, and 16 month. The changes in the GMP were studied at midbuccal (Mi-B, mesiobuccal (MB, and distobuccal sites. GT was measured presurgically, transgingivally at Mi-B and interdental sites, divided into 2 groups: Group 1 (thin and Group 2 (thick. Results: In GT of ≤1 mm group, the statistically significant apical shift of GMP led to gingival recession at all study sites in the early postsurgical period of 1 and 3 months. During 6 and 16 months, the apical shift of GMP coincided with the Chernihiv Airport at Mi-B site (6 months, MB site (16 months. The gingival recession was obvious at Mi-B sites (16 months. In the GT of >1 mm, the statistically significant apical shift of GMP did not cause gingival recession at any sites throughout postsurgical (1, 3, 6, and 16 months period. Conclusion: Thin gingiva showed apical shift of GMP leading to gingival recession as compared to thick gingiva postsurgically.

  6. Shoulder muscle function depends on elbow joint position: an illustration of dynamic coupling in the upper limb.

    Science.gov (United States)

    Yu, Jay; Ackland, David C; Pandy, Marcus G

    2011-07-07

    Shoulder muscle function has been documented based on muscle moment arms, lines of action and muscle contributions to contact force at the glenohumeral joint. At present, however, the contributions of individual muscles to shoulder joint motion have not been investigated, and the effects of shoulder and elbow joint position on shoulder muscle function are not well understood. The aims of this study were to compute the contributions of individual muscles to motion of the glenohumeral joint during abduction, and to examine the effect of elbow flexion on shoulder muscle function. A three-dimensional musculoskeletal model of the upper limb was used to determine the contributions of 18 major muscles and muscle sub-regions of the shoulder to glenohumeral joint motion during abduction. Muscle function was found to depend strongly on both shoulder and elbow joint positions. When the elbow was extended, the middle and anterior deltoid and supraspinatus were the greatest contributors to angular acceleration of the shoulder in abduction. In contrast, when the elbow was flexed at 90°, the anterior deltoid and subscapularis were the greatest contributors to joint angular acceleration in abduction. This dependence of shoulder muscle function on elbow joint position is explained by the existence of dynamic coupling in multi-joint musculoskeletal systems. The extent to which dynamic coupling affects shoulder muscle function, and therefore movement control, is determined by the structure of the inverse mass matrix, which depends on the configuration of the joints. The data provided may assist in the diagnosis of abnormal shoulder function, for example, due to muscle paralysis or in the case of full-thickness rotator cuff tears.

  7. Plasmid Dynamics in KPC-Positive Klebsiella pneumoniae during Long-Term Patient Colonization

    Directory of Open Access Journals (Sweden)

    Sean Conlan

    2016-06-01

    Full Text Available Carbapenem-resistant Klebsiella pneumoniae strains are formidable hospital pathogens that pose a serious threat to patients around the globe due to a rising incidence in health care facilities, high mortality rates associated with infection, and potential to spread antibiotic resistance to other bacterial species, such as Escherichia coli. Over 6 months in 2011, 17 patients at the National Institutes of Health (NIH Clinical Center became colonized with a highly virulent, transmissible carbapenem-resistant strain of K. pneumoniae. Our real-time genomic sequencing tracked patient-to-patient routes of transmission and informed epidemiologists’ actions to monitor and control this outbreak. Two of these patients remained colonized with carbapenemase-producing organisms for at least 2 to 4 years, providing the opportunity to undertake a focused genomic study of long-term colonization with antibiotic-resistant bacteria. Whole-genome sequencing studies shed light on the underlying complex microbial colonization, including mixed or evolving bacterial populations and gain or loss of plasmids. Isolates from NIH patient 15 showed complex plasmid rearrangements, leaving the chromosome and the blaKPC-carrying plasmid intact but rearranging the two other plasmids of this outbreak strain. NIH patient 16 has shown continuous colonization with blaKPC-positive organisms across multiple time points spanning 2011 to 2015. Genomic studies defined a complex pattern of succession and plasmid transmission across two different K. pneumoniae sequence types and an E. coli isolate. These findings demonstrate the utility of genomic methods for understanding strain succession, genome plasticity, and long-term carriage of antibiotic-resistant organisms.

  8. Dynamic symmetrical pattern projection based laser triangulation sensor for precise surface position measurement of various material types.

    Science.gov (United States)

    Žbontar, Klemen; Mihelj, Matjaž; Podobnik, Boštjan; Povše, Franc; Munih, Marko

    2013-04-20

    This paper describes a custom, material-type-independent laser-triangulation-based measurement system that utilizes a high-quality ultraviolet laser beam. Laser structuring applications demand material surface alignment regarding the laser focus position, where fabrication conditions are optimal. Robust alignment of various material types was solved by introducing dynamic symmetrical pattern projection, and a "double curve fitting" centroid detection algorithm with subsurface scattering compensation. Experimental results have shown that the measurement system proves robust to laser intensity variation, with measurement bias lower than 50 μm and standard deviation lower than ±6.3 μm for all materials. The developed probe has been integrated into a PCB prototyping system for material referencing purposes.

  9. Dynamic Modeling and Nonlinear Position Control of a Quadruped Robot with Theo Jansen Linkage Mechanisms and a Single Actuator

    Directory of Open Access Journals (Sweden)

    Shunsuke Nansai

    2015-01-01

    Full Text Available The Theo Jansen mechanism is gaining widespread popularity among the legged robotics community due to its scalable design, energy efficiency, low payload-to-machine-load ratio, bioinspired locomotion, and deterministic foot trajectory. In this paper, we perform for the first time the dynamic modeling and analysis on a four-legged robot driven by a single actuator and composed of Theo Jansen mechanisms. The projection method is applied to derive the equations of motion of this complex mechanical system and a position control strategy based on energy is proposed. Numerical simulations validate the efficacy of the designed controller, thus setting a theoretical basis for further investigations on Theo Jansen based quadruped robots.

  10. A Thrust Allocation Method for Efficient Dynamic Positioning of a Semisubmersible Drilling Rig Based on the Hybrid Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Luman Zhao

    2015-01-01

    Full Text Available A thrust allocation method was proposed based on a hybrid optimization algorithm to efficiently and dynamically position a semisubmersible drilling rig. That is, the thrust allocation was optimized to produce the generalized forces and moment required while at the same time minimizing the total power consumption under the premise that forbidden zones should be taken into account. An optimization problem was mathematically formulated to provide the optimal thrust allocation by introducing the corresponding design variables, objective function, and constraints. A hybrid optimization algorithm consisting of a genetic algorithm and a sequential quadratic programming (SQP algorithm was selected and used to solve this problem. The proposed method was evaluated by applying it to a thrust allocation problem for a semisubmersible drilling rig. The results indicate that the proposed method can be used as part of a cost-effective strategy for thrust allocation of the rig.

  11. Regulation of β-catenin nuclear dynamics by GSK-3β involves a LEF-1 positive feedback loop.

    Science.gov (United States)

    Jamieson, Cara; Sharma, Manisha; Henderson, Beric R

    2011-08-01

    Nuclear localization of β-catenin is integral to its role in Wnt signaling and cancer. Cellular stimulation by Wnt or lithium chloride (LiCl) inactivates glycogen synthase kinase-3β (GSK-3β), causing nuclear accumulation of β-catenin and transactivation of genes that transform cells. β-catenin is a shuttling protein; however, the mechanism by which GSK-3β regulates β-catenin nuclear dynamics is poorly understood. Here, fluorescence recovery after photobleaching assays were used to measure the β-catenin-green fluorescent protein dynamics in NIH 3T3 cells before and after GSK-3β inhibition. We show for the first time that LiCl and Wnt3a cause a specific increase in β-catenin nuclear retention in live cells and in fixed cells after detergent extraction. Moreover, LiCl reduced the rate of nuclear export but did not affect import, hence biasing β-catenin transport toward the nucleus. Interestingly, the S45A mutation, which blocks β-catenin phosphorylation by GSK-3β, did not alter nuclear retention or transport, implying that GSK-3β acts through an independent regulator. We compared five nuclear binding partners and identified LEF-1 as the key mediator of Wnt3a and LiCl-induced nuclear retention of β-catenin. Thus, Wnt stimulation triggered a LEF-1 positive feedback loop to enhance the nuclear chromatin-retained pool of β-catenin by 100-300%. These findings shed new light on regulation of β-catenin nuclear dynamics.

  12. Resonant photoluminescence and dynamics of a hybrid Mn hole spin in a positively charged magnetic quantum dot

    Science.gov (United States)

    Lafuente-Sampietro, A.; Boukari, H.; Besombes, L.

    2017-06-01

    We analyze, through resonant photoluminescence, the spin dynamics of an individual magnetic atom (Mn) coupled to a hole in a semiconductor quantum dot. The hybrid Mn hole spin and the positively charged exciton in a CdTe/ZnTe quantum dot form an ensemble of Λ systems which can be addressed optically. Autocorrelation of the resonant photoluminescence and resonant optical pumping experiments are used to study the spin relaxation channels in this multilevel spin system. We identified for the hybrid Mn hole spin an efficient relaxation channel driven by the interplay of the Mn hole exchange interaction and the coupling to acoustic phonons. We also show that the optical Λ systems are connected through inefficient spin flips than can be enhanced under weak transverse magnetic field. The dynamics of the resonant photoluminescence in a p -doped magnetic quantum dot is well described by a complete rate equation model. Our results suggest that long-lived hybrid Mn hole spin could be obtained in quantum dot systems with large heavy-hole/light-hole splitting.

  13. Intravital imaging of the cellular dynamics of LysM-positive cells in a murine corneal suture model.

    Science.gov (United States)

    Ueta, Mayumi; Koga, Ayaka; Kikuta, Junichi; Yamada, Keiko; Kojima, Sachi; Shinomiya, Katsuhiko; Ishii, Masaru; Kinoshita, Shigeru

    2016-03-01

    Corneal suturing is a surgical procedure used in patients with corneal trauma or transplants. It was reported that endogenous neutrophils are brightly labelled in gene-targeted mice expressing enhanced green fluorescent protein (eGFP) under the control of the endogenous lysozyme M promoter (LysM-eGFP mice). We applied intravital imaging methods to analyse in vivo the dynamics of LysM-positive granulocytes (neutrophils) in LysM-eGFP mice with corneal sutures and examined their role in the elicitation of neutrophil infiltration. We found that in the presuturing state, neutrophils strongly positive for LysM were located in the periphery of the corneal stromal layer; none were present in the centre of the cornea. After introducing a corneal suture, neutrophils accumulated in limbal vessels and then migrated to the corneal side and the conjunctival side, suggesting that they derived from limbal vessels. Thereafter they accumulated towards the central corneal area, arriving at the suture about 7 h after its placement. Although corneal sutures may elicit the continuous infiltration of neutrophils, their number was markedly decreased by day 1 after suture removal and continued to decrease thereafter. Our results showed that corneal sutures may elicit the continuous infiltration of neutrophils. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Development of DP (Dynamic Positioning) to pull-in sub sea pipelines; Utilizacao de barcos de manuseio de ancoras operando com DP (Dynamic Positioning) para arraste de dutos submarinos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Manoel H.S. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Galgoul, Elton C. [Suporte Engenharia, Luziania, GO (Brazil)

    2004-07-01

    Sub sea pipeline construction at oil and gas fields, with high concentration of on-bottom facilities, becomes more difficult when mooring operations and pipeline approach to a congested platform have to be performed. One method that has often been applied in Brazil is the so-called 'DP (Dynamic Positioning) pull-in', where PETROBRAS owned pipelay Barge, BGL-1, is moored away from the congested area, while a DP anchor handler pulls the rigid pipeline from BGL-1 to a target near the platform. The method was conceived to avoid mooring operations near the congested platforms as well as to minimize risks due to the pipeline initiation process. Inside the congested area the initiation with aid of a 'dead-man' anchor on the sea bottom, which would be a more conventional solution, becomes impossible in most cases. This paper will discuss the engineering work required to perform the 'DP pull-in' as well as show the operational steps, from the start-up to the final abandonment of the pipeline initiation head inside the target area. (author)

  15. Development of DP (Dynamic Positioning) to pull-in sub sea pipelines; Utilizacao de barcos de manuseio de ancoras operando com DP (Dynamic Positioning) para arraste de dutos submarinos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Manoel H.S. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Galgoul, Elton C. [Suporte Engenharia, Luziania, GO (Brazil)

    2004-07-01

    Sub sea pipeline construction at oil and gas fields, with high concentration of on-bottom facilities, becomes more difficult when mooring operations and pipeline approach to a congested platform have to be performed. One method that has often been applied in Brazil is the so-called 'DP (Dynamic Positioning) pull-in', where PETROBRAS owned pipelay Barge, BGL-1, is moored away from the congested area, while a DP anchor handler pulls the rigid pipeline from BGL-1 to a target near the platform. The method was conceived to avoid mooring operations near the congested platforms as well as to minimize risks due to the pipeline initiation process. Inside the congested area the initiation with aid of a 'dead-man' anchor on the sea bottom, which would be a more conventional solution, becomes impossible in most cases. This paper will discuss the engineering work required to perform the 'DP pull-in' as well as show the operational steps, from the start-up to the final abandonment of the pipeline initiation head inside the target area. (author)

  16. Modeling economic costs of disasters and recovery involving positive effects of reconstruction: analysis using a dynamic CGE model

    Directory of Open Access Journals (Sweden)

    W. Xie

    2013-11-01

    Full Text Available Disaster damages have negative effects on economy, whereas reconstruction investments have positive effects. The aim of this study is to model economic causes of disasters and recovery involving positive effects of reconstruction activities. Computable general equilibrium (CGE model is a promising approach because it can incorporate these two kinds of shocks into a unified framework and further avoid double-counting problem. In order to factor both shocks in CGE model, direct loss is set as the amount of capital stock reduced on supply side of economy; A portion of investments restore the capital stock in existing period; An investment-driven dynamic model is formulated due to available reconstruction data, and the rest of a given country's saving is set as an endogenous variable. The 2008 Wenchuan Earthquake is selected as a case study to illustrate the model, and three scenarios are constructed: S0 (no disaster occurs, S1 (disaster occurs with reconstruction investment and S2 (disaster occurs without reconstruction investment. S0 is taken as business as usual, and the differences between S1 and S0 and that between S2 and S0 can be interpreted as economic losses including reconstruction and excluding reconstruction respectively. The study showed that output from S1 is found to be closer to real data than that from S2. S2 overestimates economic loss by roughly two times that under S1. The gap in economic aggregate between S1 and S0 is reduced to 3% in 2011, a level that should take another four years to achieve under S2.

  17. Dynamical behaviors of FRW Universe containing a positive/negative potential scalar field in loop quantum cosmology

    CERN Document Server

    Liu, Xiao; Zhu, Jian-Yang

    2013-01-01

    The dynamical behaviors of FRW Universe containing a posivive/negative potential scalar field in loop quantum cosmology scenario are discussed. The method of the phase-plane analysis is used to investigate the stability of the Universe. It is found that the stability properties in this situation are quite different from the classical cosmology case. For a positive potential scalar field coupled with a barotropic fluid, the cosmological autonomous system has five fixed points and one of them is stable if the adiabatic index $\\gamma$ satisfies $0<\\gamma<2$. This leads to the fact that the universe just have one bounce point instead of the singularity which lies in the quantum dominated area and it is caused by the quantum geometry effect. There are four fixed points if one considers a scalar field with a negative potential, but none of them is stable. Therefore, the universe has two kinds of bounce points, one is caused by the quantum geometry effect and the other is caused by the negative potential, the ...

  18. Assessment of the accuracy of PPP for very-high-frequency dynamic, satellite positioning and earthquake modeling

    Science.gov (United States)

    Moschas, F.; Avallone, A.; Moschonas, N.; Saltogianni, V.; Stiros, S.

    2012-04-01

    With the advent of various GPS/GNSS Point Positioning techniques, it became possible to model the dynamic displacement history of specific points during large and rather moderate earthquakes using satellite positioning, 1Hz and occasionally 10Hz sampling data. While there is evidence that the obtained data are precise, experience from monitoring of engineering structures like bridges, indicates that GPS/GNSS records are contaminated by coloured (mostly background noise) noise even in the cases of differential-type analysis of the satellite signals. This made the necessary the assessment of the results of different PPP processing using supervised learning techniques. Our work was based on a modification of an experiment first made to assess the potential of GPS to measure oscillations of civil engineering structures. A 10Hz GNSS antenna-receiver unit was mounted on the top of a vertical rod, fixed on the ground and forced to controlled oscillations. Oscillations were also recorded by a robotic theodolite and an accelerometer, and the whole experiment was video-recorded. A second 10Hz GNSS antenna-receiver unit was left on stable ground, in a nearby position. The rod was forced to semi-static motion (bending) and then was left to oscillate freely until still, and the whole movement was recorded by all sensors. GNSS data were analyzed both in kinematic mode and in PPP mode, using the GIPSY-OASIS II (http://gipsy-oasis.jpl.nasa.gov) (only GPS) and the PPP CRCS facility (GPS + GLONAS). Recorded PPP and differential kinematic processing coordinates (apparent displacements) were found to follow the real motion, but to be contaminated by a long-period noise. On the contrary, the short-period component of the apparent PPP displacements, obtained using high-pass filtering, were very much consistent with the real motion, with sub-mm mean deviation, though occasionally contaminated by clipping. The assessment of the very-high frequency GPS noise will provide useful information

  19. Performance characteristics of positive and negative delayed feedback on chaotic dynamics of directly modulated InGaAsP semiconductor lasers

    Indian Academy of Sciences (India)

    Bindu M Krishna; Manu P John; V M Nandakumaran

    2008-12-01

    The chaotic dynamics of directly modulated semiconductor lasers with delayed optoelectronic feedback is studied numerically. The effects of positive and negative delayed optoelectronic feedback in producing chaotic outputs from such lasers with nonlinear gain reduction in its optimum value range is investigated using bifurcation diagrams. The results are confirmed by calculating the Lyapunov exponents. A negative delayed optoelectronic feedback configuration is found to be more effective in inducing chaotic dynamics to such systems with nonlinear gain reduction factor in the practical value range.

  20. Evaluation of the Dynamicity of Mitotic Exit Network and Spindle Position Checkpoint Components on Spindle Pole Bodies by Fluorescence Recovery After Photobleaching (FRAP).

    Science.gov (United States)

    Caydasi, Ayse Koca; Pereira, Gislene

    2017-01-01

    Fluorescence recovery after photobleaching (FRAP) is a powerful technique to study in vivo binding and diffusion dynamics of fluorescently labeled proteins. In this chapter, we describe how to determine spindle pole body (SPB) binding dynamics of mitotic exit network (MEN) and spindle position checkpoint (SPOC) proteins using FRAP microscopy. Procedures presented here include the growth of the yeast cultures, sample preparation, image acquisition and analysis.

  1. Dynamic virtual simulation of the occurrence and severity of edge loading in hip replacements associated with variation in the rotational and translational surgical position.

    Science.gov (United States)

    Leng, Joanna; Al-Hajjar, Mazen; Wilcox, Ruth; Jones, Alison; Barton, David; Fisher, John

    2017-04-01

    Variation in the surgical positioning of total hip replacement can result in edge loading of the femoral head on the rim of the acetabular cup. Previous work has reported the effect of edge loading on the wear of hip replacement bearings with a fixed level of dynamic biomechanical hip separation. Variations in both rotational and translational surgical positioning of the hip joint replacement combine to influence both the biomechanics and the tribology including the severity of edge loading, the amount of dynamic separation, the force acting on the rim of the cup and the resultant wear and torque acting on the cup. In this study, a virtual model of a hip joint simulator has been developed to predict the effect of variations in some surgical positioning (inclination and medial-lateral offset) on the level of dynamic separation and the contact force of the head acting on the rim as a measure of severity of edge loading. The level of dynamic separation and force acting on the rim increased with increased translational mismatch between the centres of the femoral head and the acetabular cup from 0 to 4 mm and with increased cup inclination angle from 45° to 65°. The virtual model closely replicated the dynamics of the experimental hip simulator previously reported, which showed similar dynamic biomechanical trends, with the highest level of separation being found with a mismatch of 4 mm between the centres of the femoral head and acetabular cup and 65° cup inclination angle.

  2. Effects of continuous positive airway pressure on upper airway inspiratory dynamics in awake patients with sleep-disordered breathing.

    Science.gov (United States)

    Vérin, E; Similowski, T; Sériès, F

    2003-01-01

    Continuous positive airway pressure (CPAP) is the main treatment of the obstructive sleep apnoea syndrome (OSAS). We assessed its effects on the upper airway (UA) dynamics in response to bilateral anterior magnetic phrenic nerve stimulation (BAMPS) in 17 awake untreated OSAS patients (15 males; 52 +/- 7 years) whose effective CPAP (P(eff)) had been determined beforehand by a conventional titration sleep study. All twitch-related inspirations were flow-limited, flow first rising to a maximum (V(Imax)), then decreasing to a minimum (V(Imin)), and then increasing again (M-shaped pattern). Up to V(Imin), the relationship between driving pressure (P(d)) and flow (V) could adequately be fitted to a polynomial regression model (V = k(1)P(d) + k(2)P(d)(2); r(2) = 0.71-0.98, P < 0.0001). At atmospheric pressure V(Imax) was 700 +/- 377 ml s(-1), V(Imin) was 458 +/- 306 ml s(-1), k(1) was 154.5 +/- 63.9 ml s(-1) (cmH(2)O)(-1), and k(2) was 10.7 +/- 7.3 ml s(-1) (cmH(2)O)(-1). CPAP significantly increased V(Imax) and V(Imin) (peak values 1007 +/- 332 ml and 837 +/- 264 ml s(-1), respectively) as well as k(1) and k(2) (peak values 300.9 +/- 178.2 ml s(-1) (cmH(2)O)(-1) and 55.2 +/- 65.3 ml s(-1) (cmH(2)O)(-1), respectively). With increasing CPAP, k(1)/k(2) increased up to a peak value before decreasing. We defined as P(eff,stim) the CPAP value corresponding to the highest k(1)/k(2) value. P(eff,stim) was correlated with P(eff) (P(eff) = 7.0 +/- 2.0; P(eff,stim) = 6.4 +/- 2.6 cmH(2)O; r = 0.886; 95 % CI 0.696-0.960, P < 0.001). We conclude that CPAP improves UA dynamics in OSAS and that the therapeutic CPAP to apply can be predicted during wakefulness using BAMPS.

  3. Relationship Between Respiratory Dynamics and Body Mass Index in Patients Undergoing General Anesthesia with Laryngeal Mask Airway (LMA) and Comparison Between Lithotomy and Supine Positions.

    Science.gov (United States)

    Zhao, Xiao; Huang, Shiwei; Wang, Zhaomin; Chen, Lianhua; Li, Shitong

    2016-08-01

    BACKGROUND This study aimed to compare respiratory dynamics in patients undergoing general anesthesia with a laryngeal mask airway (LMA) in lithotomy and supine positions and to validate the impact of operational position on effectiveness of LMA ventilation. MATERIAL AND METHODS A total of 90 patients (age range, 18-65 years) who underwent general anesthesia were selected and divided into supine position (SP group) and lithotomy position groups (LP group). Vital signs and respiratory dynamic parameters of the 2 groups were measured at different time points and after implantation of an LMA. The arterial blood gas was monitored at 15 min after induction. The intraoperative changes of hemodynamic indexes and postoperative adverse reactions of LMA were recorded. The possible correlation between body mass index (BMI) and respiratory dynamic indexes was analyzed. RESULTS With prolonged duration of the operation, the inspiratory plateau pressure (Pplat), inspiratory resistance (RI), and work of breathing (WOB) gradually increased, while chest-lung compliance (Compl) and partial pressure of carbon dioxide in end-expiratory gas (PetCO2) gradually decreased (all P value <0.05). The mean airway pressure (Pmean), Pplat, and expiratory resistance (Re) in the LP group were significantly higher than in the SP group (P<0.05), while the peak inspiratory flow (FImax), peak expiratory flow (FEmax), WOB, and Compl in the LP group were significantly lower than in the SP group (P<0.05). BMI was positively correlated with peak airway pressure (PIP/Ppeak), Pplat, and airway resistance (Raw) and was negatively correlated with Compl; the differences among patients in lithotomy position were more remarkable (P<0.05). CONCLUSIONS The inspiratory plateau pressure and airway resistance increased with prolonged duration of the operation, accompanied by decreased chest-lung compliance. Peak airway pressure and airway resistance were positively correlated with BMI, and chest-lung compliance was

  4. Femtosecond Hydrogen Bond Dynamics of Bulk-like and Bound Water at Positively and Negatively Charged Lipid Interfaces Revealed by 2D HD-VSFG Spectroscopy.

    Science.gov (United States)

    Singh, Prashant Chandra; Inoue, Ken-Ichi; Nihonyanagi, Satoshi; Yamaguchi, Shoichi; Tahara, Tahei

    2016-08-26

    Interfacial water in the vicinity of lipids plays an important role in many biological processes, such as drug delivery, ion transportation, and lipid fusion. Hence, molecular-level elucidation of the properties of water at lipid interfaces is of the utmost importance. We report the two-dimensional heterodyne-detected vibrational sum frequency generation (2D HD-VSFG) study of the OH stretch of HOD at charged lipid interfaces, which shows that the hydrogen bond dynamics of interfacial water differ drastically, depending on the lipids. The data indicate that the spectral diffusion of the OH stretch at a positively charged lipid interface is dominated by the ultrafast (dynamics, while the dynamics at a negatively charged lipid interface exhibit sub-picosecond dynamics almost exclusively, implying that fast hydrogen bond fluctuation is prohibited. These results reveal that the ultrafast hydrogen bond dynamics at the positively charged lipid-water interface are attributable to the bulk-like property of interfacial water, whereas the slow dynamics at the negatively charged lipid interface are due to bound water, which is hydrogen-bonded to the hydrophilic head group.

  5. Relative Orientation and Position Detections Based on an RGB-D Sensor and Dynamic Cooperation Strategies for Jumping Sensor Nodes Recycling

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2015-09-01

    Full Text Available This paper presents relative orientation and position detection methods for jumping sensor nodes (JSNs recycling. The methods are based on motion captures of the JSNs by an RGB-D sensor mounted on a carrier robot and the dynamic cooperation between the carrier and the JSNs. A disc-like label with two different colored sides is mounted on the top of the JSNs. The RGB-D sensor can detect the motion of the label to calculate the orientations and positions of the JSNs and the carrier relative to each other. After the orientations and positions have been detected, the JSNs jump into a cabin mounted on the carrier in dynamic cooperation with the carrier for recycling. The performances of the proposed methods are tested with a prototype system. The results show that the carrier can detect a JSN from up to 2 m away and sense its relative orientation and position successfully. The errors of the JSN’s orientation and position detections relative to the carrier could be reduced to the values smaller than 1° and 1 cm, respectively, by using the dynamic cooperation strategies. The proposed methods in this paper could also be used for other kinds of mobile sensor nodes and multi-robot systems.

  6. DMPD: When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18631453 When signaling pathways collide: positive and negative regulation of toll-...l) Show When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transd...uction. PubmedID 18631453 Title When signaling pathways collide: positive and neg

  7. Dynamic analysis of dynamic positioning system of vessel under different wave directions%不同浪向下船舶动力定位的动力学分析

    Institute of Scientific and Technical Information of China (English)

    张大朋; 朱克强; 严心宽; 姬芬芬

    2015-01-01

    Based on the parameters of a certain vessel with dynamic positioning system and the response ampli-tude operator(RAO), combined with the specific process of the vessel at work, the model of the vessel with dynamic positioning system was established by using OrcaFlex. With the change of the direction of wave, the dynamic analy-sis of the system was made under different wave directions. At the same time, the digital simulation of ship's surge, sway and yaw motions were made. And the extent of influence on the dynamic positioning system under different wave directions and the optimum wave direction for the operation of dynamic positioning were gotten. According to the calculated result, the optimization design of the operation of dynamic positioning for the vessel was given.%参考某动力定位船舶的具体参数和该船的海浪响应幅值算子(RAO),结合该船工作时的具体过程,利用大型水动力分析软件OrcaFlex建立了船舶动力定位时的动力学分析简化模型.通过调节不同海况下的浪向,实现了对动力定位船舶在不同浪向下的动力学分析,对海浪作用下船舶的纵荡、横荡和转艏运动进行了数值仿真,得到了不同浪向对船舶动力定位精度的影响,确定了船舶动力定位时的最佳浪向,结合计算结果,给出了船舶动力定位的优化设计方案.

  8. 高动态GPS单点定位的精度分析%Analysis of High Dynamic GPS Point Positioning Accuracy

    Institute of Scientific and Technical Information of China (English)

    白帆

    2013-01-01

      在工作中,我们经常采用GPS用户台对空中高速运动目标进跟踪测量,而普通GPS算法无法给出高动态单点定位的定位精度。运用最小二乘原理解算动态GPS用户台的定位方程,并对其进行精度评定能够得到动态单点定位精度,且简单、实用,具有很高的实际应用价值。%During operation, GPS user station is generally used to track and measure air high-speed moving-targets. The positioning accuracy of high dynamic point positioning can’t be achieved depending only on common GPS algorithm. Based on the principle of least square method, the positioning equation of dynamic GPS user station is solved. After the accuracy assessment, dynamic point positioning accuracy is obtained. The simple and practical method has a bright prospect of application.

  9. Dynamic positioning capacity system on pipe laying vessel%深水铺管船的动力定位能力评估系统

    Institute of Scientific and Technical Information of China (English)

    王川; 李辉; 任慧龙; 汪蔷

    2015-01-01

    为解决评估铺管船作业能力的难题,提出一种适用于评估铺管船动力定位能力的方法,开发了动力定位能力评估程序系统,并针对高海况环境条件设计了优化的辅助作业方案。采用数值计算方法对铺管船作业期间的平均二阶力、风载荷以及流载荷进行仿真计算,建立了环境载荷与动力定位系统提供的推力之间的平衡关系,给出了用于评估铺管船动力定位能力的系统模块,采用动力定位能力包络线的方式表达动力评估结果。在高海况作业中给出安全建议,即采用辅助拖轮作用于船舶适当位置以增强动力定位能力,从而降低工程作业风险。%To present an assessment method of dynamic positioning capacity on pipe laying vessel ,the dynamic positioning capacity system was developed ,and auxiliary plan was especially designed in a high state of the sea .The drift force ,wind loads and current loads were derived by numerical simula‐tion method .The balance relationship between the environment loads and the thrust provided by the dynamic positioning system was established .Software system was developed to estimate the dynamic positioning capacity of pipe laying vessel based on the actual work field .The dynamic positioning plot was used to reflect the final results .Safety advices that the the pattern of assist ship are suggested to enhance the dynamic position capacity in order to reduce risk during engineering operation in danger‐ous sea case .

  10. Relative Orientation and Position Detections Based on an RGB-D Sensor and Dynamic Cooperation Strategies for Jumping Sensor Nodes Recycling

    OpenAIRE

    2015-01-01

    This paper presents relative orientation and position detection methods for jumping sensor nodes (JSNs) recycling. The methods are based on motion captures of the JSNs by an RGB-D sensor mounted on a carrier robot and the dynamic cooperation between the carrier and the JSNs. A disc-like label with two different colored sides is mounted on the top of the JSNs. The RGB-D sensor can detect the motion of the label to calculate the orientations and positions of the JSNs and the carrier relative to...

  11. 船舶动力定位系统设计及150安装试验%The Design, Installation and Test of Marine Dynamic Positioning System

    Institute of Scientific and Technical Information of China (English)

    洪和平

    2012-01-01

    In order to detect and drill petrol oil and gas from deep sea, dynamic positioning system is used more and more widely in offshore engineering ships. This paper analyzes and summarizes the design, installation, test and training of marine dynamic positioning system, which is the reference for the construction of offshore engineering ships and special ships.%近年来,为了深海油气勘探和作业,船舶动力定位系统也日益广泛地应用在海洋工程船上。本文针对船舶动力定位系统的设计、安装、试验和培训进行分析和归纳,对海洋工程船舶及特种船舶具有参考价值。

  12. Measurement of the square measure of the pharynx and the positional diagnosis of airway obstruction during obstructive sleep apnea syndrome by dynamic MRI

    Energy Technology Data Exchange (ETDEWEB)

    Ozuki, Taizo; Ohkubo, Yasuo; Abe, Kimihiko [Tokyo Medical Coll. (Japan)

    2000-11-01

    The purpose of this study was to apply dynamic MRI for the positional diagnosis of airway obstruction during snoring and sleep apnea and to compare the apnea hypopnea index (AHI) and the square measure of the pharynx obtained before and after laser-assisted uvula-palate-pharyngoplasty (LAUP). From December 1997 to October 1998, dynamic MRI and overnight monitoring were performed at the hospital of Tokyo Medical University on 42 patients who complained of snoring and symptoms related to sleep apnea syndrome (SAS). Of the 42 patients, four exhibited collapse at the position of the soft palate (soft palate type) as diagnosed by dynamic MRI, and four exhibited collapse at the position of the soft palate as well as the tongue (complex type). LAUP was performed on these eight patients with obstructive SAS (OSAS). After LAUP, the AHI of these eight patients with OSAS decreased significantly (p<0.05). The square measure of the pharynx of these eight patients was increased (p<0.01). The AHI of all four patients with soft-palate obstruction decreased, and the square measure of the pharynx of three of these four patients increased. The AHI of three of four patients with the complex type decreased, while the square measure of the pharynx of two of these four patients increased. (author)

  13. Budding yeast dma proteins control septin dynamics and the spindle position checkpoint by promoting the recruitment of the Elm1 kinase to the bud neck.

    Science.gov (United States)

    Merlini, Laura; Fraschini, Roberta; Boettcher, Barbara; Barral, Yves; Lucchini, Giovanna; Piatti, Simonetta

    2012-01-01

    The first step towards cytokinesis in budding yeast is the assembly of a septin ring at the future site of bud emergence. Integrity of this ring is crucial for cytokinesis, proper spindle positioning, and the spindle position checkpoint (SPOC). This checkpoint delays mitotic exit and cytokinesis as long as the anaphase spindle does not properly align with the division axis. SPOC signalling requires the Kin4 protein kinase and the Kin4-regulating Elm1 kinase, which also controls septin dynamics. Here, we show that the two redundant ubiquitin-ligases Dma1 and Dma2 control septin dynamics and the SPOC by promoting the efficient recruitment of Elm1 to the bud neck. Indeed, dma1 dma2 mutant cells show reduced levels of Elm1 at the bud neck and Elm1-dependent activation of Kin4. Artificial recruitment of Elm1 to the bud neck of the same cells is sufficient to re-establish a normal septin ring, proper spindle positioning, and a proficient SPOC response in dma1 dma2 cells. Altogether, our data indicate that septin dynamics and SPOC function are intimately linked and support the idea that integrity of the bud neck is crucial for SPOC signalling.

  14. Budding yeast dma proteins control septin dynamics and the spindle position checkpoint by promoting the recruitment of the Elm1 kinase to the bud neck.

    Directory of Open Access Journals (Sweden)

    Laura Merlini

    Full Text Available The first step towards cytokinesis in budding yeast is the assembly of a septin ring at the future site of bud emergence. Integrity of this ring is crucial for cytokinesis, proper spindle positioning, and the spindle position checkpoint (SPOC. This checkpoint delays mitotic exit and cytokinesis as long as the anaphase spindle does not properly align with the division axis. SPOC signalling requires the Kin4 protein kinase and the Kin4-regulating Elm1 kinase, which also controls septin dynamics. Here, we show that the two redundant ubiquitin-ligases Dma1 and Dma2 control septin dynamics and the SPOC by promoting the efficient recruitment of Elm1 to the bud neck. Indeed, dma1 dma2 mutant cells show reduced levels of Elm1 at the bud neck and Elm1-dependent activation of Kin4. Artificial recruitment of Elm1 to the bud neck of the same cells is sufficient to re-establish a normal septin ring, proper spindle positioning, and a proficient SPOC response in dma1 dma2 cells. Altogether, our data indicate that septin dynamics and SPOC function are intimately linked and support the idea that integrity of the bud neck is crucial for SPOC signalling.

  15. 铺管船动力定位系统设计浅析%Design of Dynamic Positioning System of Pipelaying Vessel

    Institute of Scientific and Technical Information of China (English)

    许鹏鹏; 严婷婷; 高红梅; 赵强

    2013-01-01

    Pipelaying vessel has a wide application prospect in offshore oil and gas exploitation engineering field,with the technology development and function perfection of the pipelaying vessel,research and application of dynamic positioning system for pipelaying vessel are more important.The entire system's hardware and the network are designed based on the function of the dynamic positioning system and serial signal acquisition methods and analytical protocols are described in this article,it provides some reference for design dynamic positioning system of pipelaying vessel.%铺管船在海洋油气开发过程中有着广泛的应用前景,随着铺管船技术的发展和功能的完善,对于铺管船动力定位系统的研究和应用也显得越来越重要.本文在动力定位系统功能的基础上,构建了整个系统的硬件框架和网络结构,并且介绍了串口信号的采集方法与解析协议,希望能为铺管船动力定位系统的设计提供一定参考.

  16. Static and dynamic loading of mandibular condyles and their positional changes after bilateral sagittal split advancement osteotomies

    NARCIS (Netherlands)

    Dicker, G.J.; Tuijt, M.; Koolstra, J.H.; van Schijndel, R.A.; Castelijns, J.A.; Tuinzing, D.B.

    2012-01-01

    This study analysed the effects of change of direction of masseter (MAS) and medial pterygoid muscles (MPM) and changes of moment arms of MAS, MPM and bite force on static and dynamic loading of the condyles after surgical mandibular advancement. Rotations of the condyles were assessed on axial MRIs

  17. Sister to Sister: Dynamics of Mentoring Relationships among African American Women in Leadership and Nonleadership Positions within Higher Education

    Science.gov (United States)

    Stiff, MaNesha M.

    2013-01-01

    The purpose of this study was to identify the dynamics of mentoring relationships among African American women within the higher education profession. Utilizing a phenomenological research design, this researcher conducted in-depth interviews with 10 African American women who are mentors and/or mentees of an African American woman in the higher…

  18. Dynamic modeling and nonlinear position control of a quadruped robot with Theo Jansen linkage mechanisms and a single actuator

    OpenAIRE

    Nansai, Shunsuke; Mohan, Rajesh Elara; Tan, Ning; Rojas, Nicolas; Iwase, Masami

    2015-01-01

    The Theo Jansen mechanism is gaining widespread popularity among the legged robotics community due to its scalable design, energy efficiency, low payload-to-machine-load ratio, bioinspired locomotion, and deterministic foot trajectory. In this paper, we perform for the first time the dynamic modeling and analysis on a four-legged robot driven by a single actuator and composed of Theo Jansen mechanisms. The projection method is applied to derive the equations of motion of this complex mechanic...

  19. Static and dynamic loading of mandibular condyles and their positional changes after bilateral sagittal split advancement osteotomies.

    Science.gov (United States)

    Dicker, G J; Tuijt, M; Koolstra, J H; Van Schijndel, R A; Castelijns, J A; Tuinzing, D B

    2012-09-01

    This study analysed the effects of change of direction of masseter (MAS) and medial pterygoid muscles (MPM) and changes of moment arms of MAS, MPM and bite force on static and dynamic loading of the condyles after surgical mandibular advancement. Rotations of the condyles were assessed on axial MRIs. 16 adult patients with mandibular hypoplasia were studied. The mandibular plane angle (MPA) was 39° in Group II (n=8). All mandibles were advanced with a bilateral sagittal split osteotomy (BSSO). In Group II, BSSO was combined with Le Fort I osteotomy. Pre and postoperative moment arms of MAS, MPM and bite force were used in a two-dimensional model to assess static loading of the condyles. Pre and postoperative data on muscle cross-sectional area, volume and direction were introduced in three-dimensional dynamic models of the masticatory system to assess the loading of the condyles during opening and closing. Postsurgically, small increases of static condylar loading were calculated. Dynamic loading decreased slightly. Minor rotations of the condyles were observed. The results do not support the idea that increased postoperative condylar loading is a serious cause for condylar resorption or relapse.

  20. Development of a High Dynamic Range Beam Position Measurement system using Logarithmic Amplifiers for the SPS at CERN

    CERN Document Server

    Gonzalez, J L; Deplano, C; Savioz, J J

    2013-01-01

    A new Front-End electronics, based on Logarithmic Amplifiers, is currently being developed for the CERN SPS Multi Orbit POsition System (MOPOS). The aim is to resolve the multi-batch structure of the beams and cope with their large intensity range (> 70 dB). Position and intensity signals are digitized in the Front-End electronics installed in the tunnel. The data are then transmitted over a serial fibre-optic link to a VME Digital Acquisition board located in surface buildings. A first prototype, equipped with a calibration system, has been successfully tested on the SPS under different beam conditions, including single bunch, 25 ns and 50 ns bunch trains. The system architecture and the first beam measurements are reported in this paper

  1. Dynamic behavior of positive solutions for a leslie predator-prey system with mutual interference and feedback controls.

    Science.gov (United States)

    Zhang, Cong; Huang, Nan-jing; Deng, Chuan-xian

    2014-01-01

    We consider a Leslie predator-prey system with mutual interference and feedback controls. For general nonautonomous case, by using differential inequality theory and constructing a suitable Lyapunov functional, we obtain some sufficient conditions which guarantee the permanence and the global attractivity of the system. For the periodic case, we obtain some sufficient conditions which guarantee the existence, uniqueness, and stability of a positive periodic solution.

  2. On-treatment HBV DNA dynamics predict virological breakthrough in entecavir-treated HBeAg-positive chronic hepatitis B.

    Science.gov (United States)

    Huang, Yi-Jie; Chang, Chi-Sen; Peng, Yen-Chun; Yeh, Hong-Zen; Yang, Sheng-Shun

    2017-01-01

    Virological breakthrough (VBT) could be a manifestation of chronic hepatitis B (CHB) in patients treated with long-term nucleot(s)ide analogues. We aimed to determine the association of on-treatment serum hepatitis B virus (HBV) DNA with VBT in HBeAg-positive CHB patients receiving entecavir (ETV) treatment. A retrospective cohort study, including 162 consecutive patients (95 men and 67 women; mean age, 43.1±13.4 years) with HBeAg-positive CHB treated with ETV for at least 48 weeks between August 2008 and May 2015, was conducted. Univariate and multivariate cox regression analysis were used to identify associations with VBT and clinical factors, including HBV DNA and HBeAg serum status. Among the 162 ETV-treated HBeAg-positive CHB patients, eighteen patients (11.1%) experienced VBT (VBT group), whereas the other 144 patients were without VBT (non-VBT group). The cumulative rate of HBV DNA 100IU/mL at 48 weeks is potentially a predictor for VBT.

  3. Regulation of Nuclear Positioning and Dynamics of the Silent Mating Type Loci by the Yeast Ku70/Ku80 Complex▿

    Science.gov (United States)

    Bystricky, Kerstin; Van Attikum, Haico; Montiel, Maria-Dolores; Dion, Vincent; Gehlen, Lutz; Gasser, Susan M.

    2009-01-01

    We have examined the hypothesis that the highly selective recombination of an active mating type locus (MAT) with either HMLα or HMRa is facilitated by the spatial positioning of relevant sequences within the budding yeast (Saccharomyces cerevisiae) nucleus. However, both position relative to the nuclear envelope (NE) and the subnuclear mobility of fluorescently tagged MAT, HML, or HMR loci are largely identical in haploid a and α cells. Irrespective of mating type, the expressed MAT locus is highly mobile within the nuclear lumen, while silent loci move less and are found preferentially near the NE. The perinuclear positions of HMR and HML are strongly compromised in strains lacking the Silent information regulator, Sir4. However, HMLα, unlike HMRa and most telomeres, shows increased NE association in a strain lacking yeast Ku70 (yKu70). Intriguingly, we find that the yKu complex is associated with HML and HMR sequences in a mating-type-specific manner. Its abundance decreases at the HMLα donor locus and increases transiently at MATa following DSB induction. Our data suggest that mating-type-specific binding of yKu to HMLα creates a local chromatin structure competent for recombination, which cooperates with the recombination enhancer to direct donor choice for gene conversion of the MATa locus. PMID:19047366

  4. Performance Analysis of ToA-Based Positioning Algorithms for Static and Dynamic Targets with Low Ranging Measurements.

    Science.gov (United States)

    Ferreira, André G; Fernandes, Duarte; Catarino, André P; Monteiro, João L

    2017-08-19

    Indoor Positioning Systems (IPSs) for emergency responders is a challenging field attracting researchers worldwide. When compared with traditional indoor positioning solutions, the IPSs for emergency responders stand out as they have to operate in harsh and unstructured environments. From the various technologies available for the localization process, ultra-wide band (UWB) is a promising technology for such systems due to its robust signaling in harsh environments, through-wall propagation and high-resolution ranging. However, during emergency responders' missions, the availability of UWB signals is generally low (the nodes have to be deployed as the emergency responders enter a building) and can be affected by the non-line-of-sight (NLOS) conditions. In this paper, the performance of four typical distance-based positioning algorithms (Analytical, Least Squares, Taylor Series, and Extended Kalman Filter methods) with only three ranging measurements is assessed based on a COTS UWB transceiver. These algorithms are compared based on accuracy, precision and root mean square error (RMSE). The algorithms were evaluated under two environments with different propagation conditions (an atrium and a lab), for static and mobile devices, and under the human body's influence. A NLOS identification and error mitigation algorithm was also used to improve the ranging measurements. The results show that the Extended Kalman Filter outperforms the other algorithms in almost every scenario, but it is affected by the low measurement rate of the UWB system.

  5. The fusion dynamics for a positive Q-value system: $^{27}$Al+$^{45}$Sc using SEDF and role of spin-orbit interaction potential

    CERN Document Server

    Verma, Dalip Singh

    2016-01-01

    The fusion dynamics for a positive Q-value systems: $^{27}$Al+$^{45}$Sc, at near and deep sub-barrier energies has been investigated using the proximity potentials of Skyrme energy density formalism in semi classical extended Thomas Fermi approach for arbitrarily chosen Skyrme forces: SLy4, SIV, SGII and Proximity77 of Blocki and co-workers. The calculated fusion excitation functions for the proximity potentials obtained for Skyrme forces mentioned above and for the Proximity77 have been compared with experimental data. The proximity potential for Skyrme force SIV is found to be the best and is used in the calculations of the quantities like logarithmic derivative, barriers distributions and $S$-factor. Further, the role of spin-orbit interaction potential in the fusion dynamics of this system has been investigated.

  6. Analysis of nonlinear optical and dynamic gain effects of moderate-power, pulse-position-modulated, erbium-doped fiber amplifiers for deep-space applications.

    Science.gov (United States)

    Yao, Haomin; Wright, Malcolm W; Marciante, John R

    2014-09-20

    Lasers for use in deep-space applications such as interplanetary optical communications employ multiwatt resonantly pumped dual-clad erbium-doped fiber amplifiers and the pulse-position modulation scheme. Nonlinear optical effects and dynamic gain effects often impair their performance and limit their operational range. These effects are analyzed theoretically and numerically with a time-dependent two-level propagation model, respectively. Self-phase modulation and stimulated Raman scattering are found to limit the usable data format space. In operational regimes free from nonlinear effects, dynamic gain effects such as the variation in the output pulse energy and square-pulse distortion are quantified. Both are found to primarily depend on the symbol duration and can be as large as 28% and 21%, respectively.

  7. Nonlinear Observer Design for Ship Dynamic Positioning System%船舶动力定位系统非线性观测器设计

    Institute of Scientific and Technical Information of China (English)

    杜佳璐; 汪思源; 张显库; 李广强

    2012-01-01

    For surface ships with dynamic position,a nonlinear observer for ship dynamic positioning systems is constructed based on Luenberger observer structural principle and Lyapunov stability theory.Comparing to Kalman filter,the main advantage of the nonlinear observer is that the motion equations of ships need not be linearized and the global exponential stability is guaranteed.Finally,the simulation research is done on a supply ship,which shows that the designed nonlinear observer has good performances of filtering and state estimation.All estimations of ship movement states converge exponentially to their actual values.The effectiveness of the nonlinear observer for dynamic positioning system of ships is verified.%针对动力定位水面船舶,基于Luenberger观测器构造原理及Lyapunov稳定性理论,构造一个船舶动力定位系统的非线性状态观测器.所设计观测器较卡尔曼滤波器的主要优越性在于不需要对船舶的运动方程进行线性化处理,且具有全局的指数稳定性.最后,用一艘供给船对所设计观测器进行数值仿真研究,仿真结果表明所设计非线性观测器具有良好的滤波及状态估计性能,船舶运动状态估计值指数收敛于其实际值,验证了所设计船舶动力定位系统非线性观测器的有效性.

  8. Computational Fluid Dynamics Simulation of a Quadrupole Magnetic Sorter Flow Channel: Effect of Splitter Position on Nonspecific Crossover.

    Science.gov (United States)

    Sajja, V S K; Kennedy, David J; Todd, Paul W; Hanley, Thomas R

    2011-10-01

    In the Quadrupole Magnetic Sorter (QMS) magnetic particles enter a vertical flow annulus and are separated from non-magnetic particles by radial deflection into an outer annulus where the purified magnetic particles are collected via a flow splitter. The purity of magnetically isolated particles in QMS is affected by the migration of nonmagnetic particles across transport lamina in the annular flow channel. Computational Fluid Dynamics (CFD) simulations were used to predict the flow patterns, pressure drop and nonspecific crossover in QMS flow channel for the isolation of pancreatic islets of Langerhans. Simulation results were compared with the experimental results to validate the CFD model. Results of the simulations were used to show that one design gives up to 10% less nonspecific crossover than another and this model can be used to optimise the flow channel design to achieve maximum purity of magnetic particles.

  9. Health-Related Quality of Life Dynamics of HIV-positive South African Women up to ART Initiation: Evidence from the CAPRISA 002 Acute Infection Cohort Study

    OpenAIRE

    Tomita, Andrew; Garrett, Nigel; Werner, Lise; Burns, Jonathan K; Mpanza, Lindiwe; Mlisana, Koleka; van Loggerenberg, Francois; Karim, Salim S Abdool

    2014-01-01

    Few studies have investigated the long-term dynamics in health-related quality of life (HRQoL) among HIV-positive persons from acute infection. From 2004, 160 women were enrolled into the CAPRISA 002 Acute Infection study at two sites in the province of KwaZulu-Natal and underwent 3–6 monthly HRQoL assessments using the functional assessment of HIV infection (FAHI) instrument. Overall and 5 sub-scale FAHI scores [physical well-being (PWB), emotional well-being (EWB), functional and global wel...

  10. 动力定位系统的最新技术进展分析%Analysis of Recent Technology Advancement in Dynamic Positioning System

    Institute of Scientific and Technical Information of China (English)

    史斌杰; 吴喆莹

    2011-01-01

    随着深海技术的不断发展和推进,动力定位系统的应用越来越广泛,已成为船舶自动化技术中的一个热点问题。从动力定位系统的3个组成部分——位置测量系统、控制系统和推力系统分析了动力定位系统的现状和相关技术的最新进展。%With the development and advancement of deep-sea technologies, dynamic positioning (DP) system has wider and wider applications and has become a hot issue of marine automation technology. This paper analyzes the current status and latest advancement of DP system from its three components: position measurement systems, control systems and thrust system.

  11. Differential dynamics of histone H3 methylation at positions K4 and K9 in the mouse zygote

    Directory of Open Access Journals (Sweden)

    Walter Jörn

    2004-09-01

    Full Text Available Abstract Background In the mouse zygote the paternal genome undergoes dramatic structural and epigenetic changes. Chromosomes are decondensed, protamines replaced by histones and DNA is rapidly and actively demethylated. The epigenetic asymmetry between parental genomes remains at least until the 2-cell stage suggesting functional differences between paternal and maternal genomes during early cleavage stages. Results Here we analyzed the timing of histone deposition on the paternal pronucleus and the dynamics of histone H3 methylation (H3/K4mono-, H3/K4tri- and H3/K9di-methylation immediately after fertilization. Whereas maternal chromatin maintains all types of histone H3 methylation throughout the zygotic development, paternal chromosomes acquire new and unmodified histones shortly after fertilization. In the following hours we observe a gradual increase in H3/K4mono-methylation whereas H3/K4tri-methylation is not present before latest pronuclear stages. Histone H3/K9di-methylation is completely absent from the paternal pronucleus, including metaphase chromosomes of the first mitotic stage. Conclusion Parallel to the epigenetic asymmetry in DNA methylation, chromatin modifications are also different between both parental genomes in the very first hours post fertilization. Whereas methylation at H3/K4 gradually becomes similar between both genomes, H3/K9 methylation remains asymmetric.

  12. Hidden spondylolisthesis: unrecognized cause of low back pain? Prospective study about the use of dynamic projections in standing and recumbent position for the individuation of lumbar instability

    Energy Technology Data Exchange (ETDEWEB)

    Landi, Alessandro; Gregori, Fabrizio; Marotta, Nicola; Donnarumma, Pasquale; Delfini, Roberto [University of Rome - Policlinico Umberto I, Department of Neurology and Psychiatry, Division of Neurosurgery, Rome (Italy)

    2015-03-26

    Dynamic X-rays (DXR) are widely recognized as an effective method to detect lumbar instability (LI). They are usually performed with the patient in standing position (SDXR). In our opinion, standing position inhibits micromovements of the lumbar segment interested by the listhesis, thanks to paravertebral muscles antalgic contraction and augmented tone. We aim to demonstrate that DXR in recumbent position (RDXR), reducing the action of paravertebral muscles, can discover hypermovements not evidenced in SDXR. Between January 2011 and January 2013, we studied 200 consecutive patients with lumbar degenerative disease with MRI, SDXR, and RDXR. We aimed to find a correlation between low back or radicular pain and the presence of a spondylolisthesis not showed by the SDXR, but showed by the RDXR. We analysed 200 patients: of the 133 not pathologic in SDXR, 43 patients (32.3 %) showed an hypermovement in RDXR (p = 0.0001) without any significant correlation between hidden listhesis and age, sex, or level involved. The aim of our study is to determine whether in patients with lumbalgy without evidence of listhesis in SDXR, pain can be attributed to a faccettal syndrome or to a spondylolisthesis. Consequence of pain is augmented muscular tone of the paravertebral musculature, particularly in standing position. Augmented muscular tone tries to inhibit the pain generator, attempting to limit the slippage of the involved segment. In patients examined in RDXR, the tone of paravertebral musculature is reduced, showing the hidden spondylolisthesis. (orig.)

  13. From static to dynamic 1.5T MRI-linac prototype: impact of gantry position related magnetic field variation on image fidelity.

    Science.gov (United States)

    Crijns, Sjoerd; Raaymakers, Bas

    2014-07-07

    Recently, the MRI-linac prototype at UMC Utrecht was upgraded with a ring-based gantry, where all linac components are mounted on a ring around the MR scanner. Although adaptations have been made to both linac and MR magnets in order to account for mutual magnetic interference, interference problems cannot be ruled out completely. Therefore, in this paper the impact of gantry position dependent magnetic field inhomogeneity variation on the geometrical accuracy of acquired MR images is quantified. Magnetic field maps were acquired in a large field of view for static gantry positions in shimmed and un-shimmed conditions. Reproducibility of the shim settings was assessed. From the fieldmaps, a minimum gradient strength needed to acquire images with geometric distortions of, at most, 1 mm was derived. Moreover, imaging during gantry rotation was performed for a range of imaging parameters and rotation speeds. From the measurements we conclude that images with good geometric fidelity can be obtained for all static gantry positions, provided that shimming is performed for each new gantry position. This indicates that the present prototype is suitable for static IMRT scenarios. Shim settings are highly reproducible, suggesting that shimming via look-up tables is feasible. Finally, imaging during gantry rotation may produce severely distorted images at present and is likely to require advanced compensation methods such as dynamic shimming or higher order reconstruction.

  14. Coupling time-domain analysis of dynamic positioning during S-lay operations%全耦合S型铺管动力定位时域分析

    Institute of Scientific and Technical Information of China (English)

    孙丽萍; 朱建勋; 艾尚茂; 刘胜楠

    2015-01-01

    In order to study the performance of dynamic positioning system during S-lay operations, the system is simulated with the hull-stinger-pipe coupling effect. The roller of stinger is simulated based on the generalized elastic contact theory. The stinger is composed of Morrison members. The force on pipe is calculated by lumped mass method. The time domain of fully coupled barge model is analyzed combining with PID controller, Kalman filter and allocation of thrust using Sequential Quadratic Programming method. The effect of hull wave frequency motion on pipe-stinger coupling force and dynamic positioning system is also analyzed. And how S-lay operations affect the dynamic positioning accuracy is studied. The simulation results are proved to be available by checking pipe stress with API criterion. The effect of heave and yaw motion cannot be ignored on hull-stinger-pipe coupling force and the dynamic positioning system. It is important to decrease the barge’ s pitch motion and lay pipes in head sea in order to improve the safety of the S-lay installation and dynamic positioning.%为研究S型铺管船铺管工况下的动力定位系统性能,进行了船体-托管架-管道的耦合作用下的动力定位模拟。采用广义弹性面接触法模拟托管架上托辊,莫里森杆构建托管架模型,集中质量法计算管道受力,并应用PID和Kalman滤波相结合的控制系统和序列二次规划法进行分配的推力系统,进行了全耦合S型铺管动力定位时域分析;研究了船体波频运动对于管道-托管架耦合作用力和动力定位系统的影响;比较分析了铺管工况和非铺管工况下的定位精度影响;同时应用API规范对管道应力进行校核,验证了该耦合模拟的正确性。结果表明,垂荡和艏摇对于管道-托管架-船体之间的耦合作用力对动力定位系统影响很大,在动力定位系统设计时,需要着重考虑。减小纵摇和迎浪铺管是

  15. High Dynamic GPS Positioning Model Based on Nonlinear Filter Algorithm%基于非线性滤波算法的高动态GPS定位模型

    Institute of Scientific and Technical Information of China (English)

    范韬; 茅旭初

    2011-01-01

    运动载体上的GPS接收机在高动态环境下运行时,由于接收机与卫星的相对加速度和速度均过大,测得的伪距和多普勒频移均存在较大的误差,而现有的GPS定位模型动态建模较为简单,导致系统在高动态环境下定位精度很低.提出一种改进的GPS系统模型,将接收机加速度信息引入到系统状态变量中进行估计,测量模型和状态模型均随接收到的卫星颗数而动态改变,并使用了平淡卡尔曼滤波进行定位解算,结果证明,使GPS系统在高动态环境下仍能得出较高的定位精度,并有定位模型的有效性和较强的鲁棒性.%In high dynamic environment, there are large errors in Pseudorange and the Doppler Shift due to the high speed and relative acceleration of the satellite and the receiver. The existing GPS models are too simple that the positioning accuracy becomes low in the high motion environment. In this paper, an improved CPS positioning model is presented. The accelerations of the receiver are added to the system state variables. The measurement model and the state model both vary according to the numbers of available satellites. Furthermore, Unscented Kalman Filter ( UKF) is employed, which maintains the high positioning accuracy in the high dynamic environment and has a reliable robustness.

  16. Farnesyltransferase inhibitor treatment restores chromosome territory positions and active chromosome dynamics in Hutchinson-Gilford progeria syndrome cells

    Science.gov (United States)

    2011-01-01

    Background Hutchinson-Gilford progeria syndrome (HGPS) is a premature ageing syndrome that affects children leading to premature death, usually from heart infarction or strokes, making this syndrome similar to normative ageing. HGPS is commonly caused by a mutation in the A-type lamin gene, LMNA (G608G). This leads to the expression of an aberrant truncated lamin A protein, progerin. Progerin cannot be processed as wild-type pre-lamin A and remains farnesylated, leading to its aberrant behavior during interphase and mitosis. Farnesyltransferase inhibitors prevent the accumulation of farnesylated progerin, producing a less toxic protein. Results We have found that in proliferating fibroblasts derived from HGPS patients the nuclear location of interphase chromosomes differs from control proliferating cells and mimics that of control quiescent fibroblasts, with smaller chromosomes toward the nuclear interior and larger chromosomes toward the nuclear periphery. For this study we have treated HGPS fibroblasts with farnesyltransferase inhibitors and analyzed the nuclear location of individual chromosome territories. We have found that after exposure to farnesyltransferase inhibitors mis-localized chromosome territories were restored to a nuclear position akin to chromosomes in proliferating control cells. Furthermore, not only has this treatment afforded chromosomes to be repositioned but has also restored the machinery that controls their rapid movement upon serum removal. This machinery contains nuclear myosin 1β, whose distribution is also restored after farnesyltransferase inhibitor treatment of HGPS cells. Conclusions This study not only progresses the understanding of genome behavior in HGPS cells but demonstrates that interphase chromosome movement requires processed lamin A. PMID:21838864

  17. [Dynamic and cinematic evaluation of the function of bioprosthesis in the aortic position: tester of cardiac valves].

    Science.gov (United States)

    Bustamante, J; Santamaría, J; Infante, O; Flores, P; Juárez, A

    1996-01-01

    Twenty four pericardial valvular prostheses were tested in a valvular tester device. The valves considered were: 12 valves of the model that has being already in clinical use, manufactured in the Instituto Nacional de Cardiología "Ignacio Chávez", (INC II) and 12 valves of a model in an experimental stage, (PRT I.) The inner diameter in the two group considered were: 17, 19 and 21 mm. All the valves were tested in the aortic position in the valvular tester device. Behavior of the valvular prostheses were examined at various rates of pulsation, 60, 77, 105 and 159 per minute, with an ejection volume of 70 and 80 ml (range of flows between 4200 and 12720 ml min1). The pressure of the ventricular and aortic cameras were registered continuously, by external transducers, and in the other hand, the kinetic of the valves and the degree of opening were evaluated for direct view trough an special window. The grade of incompetence was too evaluated and expressed in percent of the stroke volume. The transvalvular pressure gradient was lower in INC II model valves, specially at moderate and high flows, and at same time had a largest functional area. The degree of incompetence was higher in the 19 and 21 mm diameter valvular subgroups than the same subgroups in the PRT I model. In relation to the 17 mm subgroup, significant differences were not find. The use of the valvular tester showed a basic utility in the hydrodynamic evaluation of the news bioprostheses design, and so in the quality control of the valves than has being manufacturing.

  18. Control law design of dynamic positioning for ship based on dynamic surface control%基于动态面控制的船舶动力定位控制律设计

    Institute of Scientific and Technical Information of China (English)

    杜佳璐; 杨杨; 胡鑫; 陈海泉

    2014-01-01

    The control problem of dynamic positioning for surface ship was analyzed,the time-variant environmental disturbances with unknown bounds were considered,the dynamic surface control technology was combined with the vectorial backstepping method,based on which,an adaptive robust nonlinear control law of dynamic positioning was proposed.By introducing the dynamic surface control technique,the proposed control law utilized the differentiation term of the first-order low-pass filter to replace the differentiation term of virtual control vector.As a result,the differentiation operations in the control law design were replaced by the simple algebraic operations.Hence,the control law simplified the computation and was implemented in engineering practice easily. Leakage terms based on a variation of σ-modification were incorporated into the adaptive laws for estimating the unknown bounds of disturbances to prevent parameters from drifting.By using the Lyapunov function,it was proved that the proposed control law could force the ship’ s position and heading to converge and keep at the desired target values and guarantee the uniformly ultimate boundedness of all signals in the closed-loop dynamic positioning system of ship.Simulation result shows that as the initial horizontal-plane position of ship deviates 25 m from the desired position,the ship can achieve the desired position within 50 s based on the control law,so the proposed control law is effective.1 tab,7 figs,15 refs.%针对水面船舶动力定位控制问题,考虑带有未知界的时变环境扰动,将动态面控制技术与矢量逆推方法相结合,设计了船舶动力定位系统的自适应鲁棒非线性控制律。引入动态面控制技术,利用一阶滤波器的微分项代替虚拟控制矢量的微分项,使得在控制律设计过程中的微分运算被简单的代数运算所替代,简化了计算,易于工程实现。为阻止自适应参数漂移

  19. Development of a video image-based QA system for the positional accuracy of dynamic tumor tracking irradiation in the Vero4DRT system

    Energy Technology Data Exchange (ETDEWEB)

    Ebe, Kazuyu, E-mail: nrr24490@nifty.com; Tokuyama, Katsuichi; Baba, Ryuta; Ogihara, Yoshisada; Ichikawa, Kosuke; Toyama, Joji [Joetsu General Hospital, 616 Daido-Fukuda, Joetsu-shi, Niigata 943-8507 (Japan); Sugimoto, Satoru [Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421 (Japan); Utsunomiya, Satoru; Kagamu, Hiroshi; Aoyama, Hidefumi [Graduate School of Medical and Dental Sciences, Niigata University, Niigata 951-8510 (Japan); Court, Laurence [The University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009 (United States)

    2015-08-15

    Purpose: To develop and evaluate a new video image-based QA system, including in-house software, that can display a tracking state visually and quantify the positional accuracy of dynamic tumor tracking irradiation in the Vero4DRT system. Methods: Sixteen trajectories in six patients with pulmonary cancer were obtained with the ExacTrac in the Vero4DRT system. Motion data in the cranio–caudal direction (Y direction) were used as the input for a programmable motion table (Quasar). A target phantom was placed on the motion table, which was placed on the 2D ionization chamber array (MatriXX). Then, the 4D modeling procedure was performed on the target phantom during a reproduction of the patient’s tumor motion. A substitute target with the patient’s tumor motion was irradiated with 6-MV x-rays under the surrogate infrared system. The 2D dose images obtained from the MatriXX (33 frames/s; 40 s) were exported to in-house video-image analyzing software. The absolute differences in the Y direction between the center of the exposed target and the center of the exposed field were calculated. Positional errors were observed. The authors’ QA results were compared to 4D modeling function errors and gimbal motion errors obtained from log analyses in the ExacTrac to verify the accuracy of their QA system. The patients’ tumor motions were evaluated in the wave forms, and the peak-to-peak distances were also measured to verify their reproducibility. Results: Thirteen of sixteen trajectories (81.3%) were successfully reproduced with Quasar. The peak-to-peak distances ranged from 2.7 to 29.0 mm. Three trajectories (18.7%) were not successfully reproduced due to the limited motions of the Quasar. Thus, 13 of 16 trajectories were summarized. The mean number of video images used for analysis was 1156. The positional errors (absolute mean difference + 2 standard deviation) ranged from 0.54 to 1.55 mm. The error values differed by less than 1 mm from 4D modeling function errors

  20. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  1. On the nonlinear dynamics of a position-dependent mass-driven Duffing-type oscillator: Lagrange and Newton equations' equivalence

    CERN Document Server

    Mustafa, Omar

    2013-01-01

    Using a generalized coordinate along with a proper invertible coordinate transformation, we show that the Euler-Lagrange equation used by Bagchi et al. 16 is in clear violation of the Hamilton's principle. We also show that Newton's equation of motion they have used is not in a form that satisfies the dynamics of position-dependent mass (PDM) settings.. The equivalence between Euler-Lagrange's and Newton's equations is now proved and documented through the proper invertible coordinate transformation and the introduction of a new PDM byproducted reaction-type force. The total mechanical energy for the PDM is shown to be conservative (i.e., dE/dt=0, unlike Bagchi et al.'s 16 observation).

  2. The development and research method of dynamic positioning system%动力定位系统发展状况及研究方法

    Institute of Scientific and Technical Information of China (English)

    赵志高; 杨建民; 王磊; 程俊勇

    2002-01-01

    动力定位系统(Dynamic Positioning System)是一种闭环的控制系统,其采用推力器来提供抵抗风、浪、流等作用在船上的环境力,从而使船尽可能地保持在海平面上要求的位置上,其定位成本不会随着水深增加而增加,并且操作也比较方便.本文对动力定位系统发展及各组成部分进行了介绍,以期对动力定位系统有个比较完整的认识.

  3. Study on the disturbing forces for dynamic positioning system of ocean floating structures%海上浮体动力定位外力计算

    Institute of Scientific and Technical Information of China (English)

    王先福; 杨建民; 王磊

    2005-01-01

    动力定位系统(dynamic positioning system)是一种闭环自动控制系统,采用推力器来抵抗风、浪、流等作用在浮体上的环境力,使其保持在所要求的位置上.船舶的风和流作用力由经验公式求得,波浪力主要考虑二阶漂移力,由三维势流理论的直接积分法求得.通过模拟仿真,表明其结果能够用于船舶动力定位系统研究.

  4. A dynamic developmental link between verbal comprehension-knowledge (Gc) and reading comprehension: verbal comprehension-knowledge drives positive change in reading comprehension.

    Science.gov (United States)

    Reynolds, Matthew R; Turek, Joshua J

    2012-12-01

    Intelligence and general academic achievement have a well-established relation, but the interrelated development of the two constructs over time is less well-known. In this study, the dynamic developmental relation between verbal comprehension-knowledge (Gc) and reading comprehension was examined by applying bivariate dual change score models (McArdle, 2009) to longitudinal data collected from children aged 9 through 15 who were part of the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (NICHD SECCYD). A unidirectional dynamic link was found in which higher levels of prior Gc led to increased positive change in reading comprehension scores. This unidirectional link was not altered by including intelligence measured at 24-months, SES, sex, basic reading, and reading volume as time-invariant covariates. Gc is a leading indicator of reading comprehension and should be considered when developing and monitoring long-term reading comprehension interventions for children. Copyright © 2012 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  5. High Dynamics and Precision Optical Measurement Using a Position Sensitive Detector (PSD in Reflection-Mode: Application to 2D Object Tracking over a Smart Surface

    Directory of Open Access Journals (Sweden)

    Ioan Alexandru Ivan

    2012-12-01

    Full Text Available When related to a single and good contrast object or a laser spot, position sensing, or sensitive, detectors (PSDs have a series of advantages over the classical camera sensors, including a good positioning accuracy for a fast response time and very simple signal conditioning circuits. To test the performance of this kind of sensor for microrobotics, we have made a comparative analysis between a precise but slow video camera and a custom-made fast PSD system applied to the tracking of a diffuse-reflectivity object transported by a pneumatic microconveyor called Smart-Surface. Until now, the fast system dynamics prevented the full control of the smart surface by visual servoing, unless using a very expensive high frame rate camera. We have built and tested a custom and low cost PSD-based embedded circuit, optically connected with a camera to a single objective by means of a beam splitter. A stroboscopic light source enhanced the resolution. The obtained results showed a good linearity and a fast (over 500 frames per second response time which will enable future closed-loop control by using PSD.

  6. High dynamics and precision optical measurement using a position sensitive detector (PSD) in reflection-mode: application to 2D object tracking over a Smart Surface.

    Science.gov (United States)

    Ivan, Ioan Alexandru; Ardeleanu, Mihai; Laurent, Guillaume J

    2012-12-06

    When related to a single and good contrast object or a laser spot, position sensing, or sensitive, detectors (PSDs) have a series of advantages over the classical camera sensors, including a good positioning accuracy for a fast response time and very simple signal conditioning circuits. To test the performance of this kind of sensor for microrobotics, we have made a comparative analysis between a precise but slow video camera and a custom-made fast PSD system applied to the tracking of a diffuse-reflectivity object transported by a pneumatic microconveyor called Smart-Surface. Until now, the fast system dynamics prevented the full control of the smart surface by visual servoing, unless using a very expensive high frame rate camera. We have built and tested a custom and low cost PSD-based embedded circuit, optically connected with a camera to a single objective by means of a beam splitter. A stroboscopic light source enhanced the resolution. The obtained results showed a good linearity and a fast (over 500 frames per second) response time which will enable future closed-loop control by using PSD.

  7. Lanthanide dinuclear complexes constructed from mixed oxygen-donor ligands: the effect of substituent positions of the neutral ligand on the magnetic dynamics in Dy analogues.

    Science.gov (United States)

    Zhu, Wen-Hua; Li, Shan; Gao, Chen; Xiong, Xia; Zhang, Yan; Liu, Li; Powell, Annie K; Gao, Song

    2016-03-21

    Two series of lanthanide dinuclear complexes with the general formulae, [Ln(n-PNO)(Bza)3(H2O)] {Bza = benzoic acid; n = 3, n-PNO = 3-picoline N-oxide, Dy(1) and Er(2); and n = 4, n-PNO = 4-picoline N-oxide, Nd(3), Eu(4), Gd(5), Tb(6), Dy(7), Er(8) and Y(9)} have been successfully synthesized by the hydrothermal method. Single-crystal X-ray diffraction experiments illustrate that the two series of compounds possess similar carboxylic ligand-bridged dinuclear structure and coordination geometry around the lanthanide ions despite the different methyl-substituent positions on the neutral ligand. Comparative studies of the Dy analogues in the static-field measurements reveal only a little difference with a small butterfly-shaped opening for complex 1 and a close hysteresis loop for 7 at 2.0 K. However, systematic investigations of the alternating-current (ac) measurements indicate that the different substituent positions of the picoline N-oxide ligand have a significant effect on the magnetic relaxation dynamics. A more substantial suppression of the quantum tunnelling of magnetization (QTM) effect and pronounced slow magnetic relaxation were observed in complex 7 as compared to 1 under both zero and a 1 kOe static field.

  8. Positioning magnetorheological actuator

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, Valery; Bazinenkov, Alexey; Akimov, Igor [Bauman Moscow State Technical University, 2-nd Baumanskaia st. 5, MT-11, 105005, Moscow (Russian Federation); Borin, Dmitry [Technische Universitaet Dresden, Chair of Magnetofluiddynamics, 01062, Dresden (Germany)], E-mail: mikhailov@bmstu.ru

    2009-02-01

    In this work we consider a construction of a positioning magnetorheological actuator based on bellow units, as well as dynamical model, which include such elements as a magnetically hysteresis, pressure loses in hydraulic system, nonlinearity of rheological behaviour of working fluid. Two operating modes of positioning actuator are taken into account and transients are presented. Dynamical modelling shows possibility for the improvement of a real control system and ensure of submicron precision of positioning with millisecond time of response.

  9. Research on Thrust Allocation of Ship Dynamic Positioning System%船舶动力定位系统推力分配策略研究

    Institute of Scientific and Technical Information of China (English)

    王钦若; 杨娜; 叶宝玉; 熊建斌

    2013-01-01

    针对船舶动力定位系统推力分配过程中推进系统的燃油消耗大、推进器磨损严重、推力误差存在等现象,提出一种以带权重的伪逆算法为基础、合理高效地解决船舶推力分配问题的方法.整个推力优化分配的目标是使推进系统的能耗最小,同时考虑推进器的方位角变化速率,推进器的推力禁区、推力饱和限制等情况,静态解决方法给出了基于最小能量的各推力的优化方向,在考虑禁止角情况下,全回转推进器方向角可以缓慢变化,而动态解决方法提供了动态能力.两者结合后,成为一种以能量优化为目的的推力分配算法.经仿真验证,静态和动态相结合的推力分配算法要比纯静态的算法消耗更少的能量,而且误差更小,应用前景比较广泛.%Based on the pseudo inverse algorithm with the weights, a rational and effective method of solving thrust allocation of ship is proposed. Because thrust allocation of ship dynamic positioning system causes fuel consumption of propulsion system, badly worn of thrusters and thrust error and so on. The whole thrust optimization allocation goal is to minimize energy consumption of the propulsion system, taking into account the rate of change of the angle of azimuth thrusters, prohibited area of thrust of thrusters, saturation and restriction of thrust and so on. Static solution gives thrust directions based on minimum energy. The direction angle of azimuth thrusters can slowly change, in considering banning angle cases. Dynamic solutions provides dynamic ability. After the combination, it become a kind of thrust allocation algorithm for the purpose of optimizing energy. The simulation results show that the combination of dynamic and static algorithms consumes less energy and the error is smaller than pure static algorithm. There is more extensive application prospect.

  10. Research on time domain simulation of dynamic positioning for a deep water semi-submersible platform%深水半潜平台动力定位时域模拟研究

    Institute of Scientific and Technical Information of China (English)

    王磊; 孙攀; 王亮

    2011-01-01

    Based on time domain low frequency equations of horizontal motion, considering all low frequency environment loads and dynamic positioning model, a time domain simulation system of power consumption for a semi-submersible platform was established. In this paper, the law of power consumption of dynamic positioning system for a platform was researched. On the premise of meeting the positioning accuracy, the limit water depth which the dynamic positioning system can withstand was calculated, and the positioning accuracy changes with the power consumption of the dynamic positioning system for the platform was also discussed, in order to provide a guidance for engineering practice.%以低频时域水平运动方程为基础,考虑各种低频载荷作用以及动力定位模型,建立起一种半潜平台功率消耗的时域模拟系统,研究了一艘半潜平台动力定位系统功率消耗变化的规律,在满足定位精度要求的前提下计算得到了平台动力定位系统能够承受的极限水深,并对平台动力系统的定位精度随功率消耗的变化进行了探讨,以期为工程实际提供指导.

  11. Interphase cell cycle dynamics of a late-replicating, heterochromatic homogeneously staining region: precise choreography of condensation/decondensation and nuclear positioning.

    Science.gov (United States)

    Li, G; Sudlow, G; Belmont, A S

    1998-03-09

    Recently we described a new method for in situ localization of specific DNA sequences, based on lac operator/repressor recognition (Robinett, C.C., A. Straight, G. Li, C. Willhelm, G. Sudlow, A. Murray, and A.S. Belmont. 1996. J. Cell Biol. 135:1685-1700). We have applied this methodology to visualize the cell cycle dynamics of an approximately 90 Mbp, late-replicating, heterochromatic homogeneously staining region (HSR) in CHO cells, combining immunostaining with direct in vivo observations. Between anaphase and early G1, the HSR extends approximately twofold to a linear, approximately 0.3-mum-diam chromatid, and then recondenses to a compact mass adjacent to the nuclear envelope. No further changes in HSR conformation or position are seen through mid-S phase. However, HSR DNA replication is preceded by a decondensation and movement of the HSR into the nuclear interior 4-6 h into S phase. During DNA replication the HSR resolves into linear chromatids and then recondenses into a compact mass; this is followed by a third extension of the HSR during G2/ prophase. Surprisingly, compaction of the HSR is extremely high at all stages of interphase. Preliminary ultrastructural analysis of the HSR suggests at least three levels of large-scale chromatin organization above the 30-nm fiber.

  12. Dynamic Positioning System and its Commissioning%动力定位系统浅析及调试工艺

    Institute of Scientific and Technical Information of China (English)

    徐业会; 潘劭华

    2014-01-01

    动力定位系统在浮式海洋工程领域应用非常广泛,随着全球深水油气资源开发的加速,该技术的发展和应用将更加成熟。本文简述了动力定位系统及其基本组成,结合现场的调试经验,重点介绍系统调试的流程和需测试的功能,对调试过程中常见问题和解决方法进行了分析探讨。%Dynamic positioning(DP) system is widely used in lfoating marine engineering and great progress will be made in the application of it with rapid exploration of global deepwater oil gas resources. DP system and its commissioning are introduced in this paper, focusing on commissioning procedure, functions to be tested, common problems and troubleshooting during commissioning based on commissioning experience.

  13. Colorimetric and dynamic light scattering detection of DNA sequences by using positively charged gold nanospheres: a comparative study with gold nanorods

    Science.gov (United States)

    Pylaev, T. E.; Khanadeev, V. A.; Khlebtsov, B. N.; Dykman, L. A.; Bogatyrev, V. A.; Khlebtsov, N. G.

    2011-07-01

    We introduce a new genosensing approach employing CTAB (cetyltrimethylammonium bromide)-coated positively charged colloidal gold nanoparticles (GNPs) to detect target DNA sequences by using absorption spectroscopy and dynamic light scattering. The approach is compared with a previously reported method employing unmodified CTAB-coated gold nanorods (GNRs). Both approaches are based on the observation that whereas the addition of probe and target ssDNA to CTAB-coated particles results in particle aggregation, no aggregation is observed after addition of probe and nontarget DNA sequences. Our goal was to compare the feasibility and sensitivity of both methods. A 21-mer ssDNA from the human immunodeficiency virus type 1 HIV-1 U5 long terminal repeat (LTR) sequence and a 23-mer ssDNA from the Bacillus anthracis cryptic protein and protective antigen precursor (pagA) genes were used as ssDNA models. In the case of GNRs, unexpectedly, the colorimetric test failed with perfect cigar-like particles but could be performed with dumbbell and dog-bone rods. By contrast, our approach with cationic CTAB-coated GNPs is easy to implement and possesses excellent feasibility with retention of comparable sensitivity—a 0.1 nM concentration of target cDNA can be detected with the naked eye and 10 pM by dynamic light scattering (DLS) measurements. The specificity of our method is illustrated by successful DLS detection of one-three base mismatches in cDNA sequences for both DNA models. These results suggest that the cationic GNPs and DLS can be used for genosensing under optimal DNA hybridization conditions without any chemical modifications of the particle surface with ssDNA molecules and signal amplification. Finally, we discuss a more than two-three-order difference in the reported estimations of the detection sensitivity of colorimetric methods (0.1 to 10-100 pM) to show that the existing aggregation models are inconsistent with the detection limits of about 0.1-1 pM DNA and that

  14. Colorimetric and dynamic light scattering detection of DNA sequences by using positively charged gold nanospheres: a comparative study with gold nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Pylaev, T E; Khanadeev, V A; Khlebtsov, B N; Dykman, L A; Bogatyrev, V A; Khlebtsov, N G, E-mail: khlebtsov@ibppm.sgu.ru [Institute of Biochemistry and Physiology of Plants and Microorganisms, RAS, 13 Prospekt Entuziastov, Saratov 410049 (Russian Federation)

    2011-07-15

    We introduce a new genosensing approach employing CTAB (cetyltrimethylammonium bromide)-coated positively charged colloidal gold nanoparticles (GNPs) to detect target DNA sequences by using absorption spectroscopy and dynamic light scattering. The approach is compared with a previously reported method employing unmodified CTAB-coated gold nanorods (GNRs). Both approaches are based on the observation that whereas the addition of probe and target ssDNA to CTAB-coated particles results in particle aggregation, no aggregation is observed after addition of probe and nontarget DNA sequences. Our goal was to compare the feasibility and sensitivity of both methods. A 21-mer ssDNA from the human immunodeficiency virus type 1 HIV-1 U5 long terminal repeat (LTR) sequence and a 23-mer ssDNA from the Bacillus anthracis cryptic protein and protective antigen precursor (pagA) genes were used as ssDNA models. In the case of GNRs, unexpectedly, the colorimetric test failed with perfect cigar-like particles but could be performed with dumbbell and dog-bone rods. By contrast, our approach with cationic CTAB-coated GNPs is easy to implement and possesses excellent feasibility with retention of comparable sensitivity-a 0.1 nM concentration of target cDNA can be detected with the naked eye and 10 pM by dynamic light scattering (DLS) measurements. The specificity of our method is illustrated by successful DLS detection of one-three base mismatches in cDNA sequences for both DNA models. These results suggest that the cationic GNPs and DLS can be used for genosensing under optimal DNA hybridization conditions without any chemical modifications of the particle surface with ssDNA molecules and signal amplification. Finally, we discuss a more than two-three-order difference in the reported estimations of the detection sensitivity of colorimetric methods (0.1 to 10-100 pM) to show that the existing aggregation models are inconsistent with the detection limits of about 0.1-1 pM DNA and that

  15. Dynamic positioning system thrust allocation algorithm with dynamical thrust constrains of semi-submersible platform%半潜式平台动力定位系统控制力动态约束分配法

    Institute of Scientific and Technical Information of China (English)

    梁海志; 欧进萍

    2012-01-01

    半潜式平台动力定位推力分配系统通过计算每个推力器的推力和推力角,将控制力分配到推力系统的各推力器上.基于系统耗能最小模式,根据推力器之间的损失模型,通过动态设置推力可行域,将推力分配问题转化为求解二次型优化模型.考虑推力器的物理性能,以推力变化率和转角变化速率为控制参数,利用序列二次规划法得到数值计算结果.该方法充分考虑推力器的物理性能,降低推力器的机械磨损,且可以避免处理可行域为非凸集问题,有效地提高推力器的推力效率.%Dynamic positioning systems thrust allocation system of semisubmersible platform allocates the control force to propellers by calculating each propellers thrust and angle. Based on minimum system power consumption mode and thrust loss mode between propellers , this paper builds a quadratic optimal problem by setting a dynamical thrust feasible region. In order to make sure of systems safety , one showd select rate of change of thrust and angle as optimal parameters and give numerical results by sequential quadratic programming. This method considers the physical properties of thrusters and reduces the propellers'mechanics wear and tear. Meanwhile, the method also avoids the processing feasible region to be non-convex and effectively improves thrust efficiency.

  16. POSITIVE EQUILIBRIUM AND ITS STABILITY OF THE BEDDINGTON-DEANGELIS'TYPE PREDATOR-PREY DYNAMICAL SYSTEM%Beddington-DeAngelis型捕食-食饵动力系统的正平衡点及其稳定性

    Institute of Scientific and Technical Information of China (English)

    肖海滨

    2006-01-01

    A class of Beddington-DeAngelis' type predator-prey dynamic system with prey and predator both having linear density restriction is considered. By using the qualitative methods of ODE, the existence and uniqueness of positive equilibrium and its global asymptotic stability are analyzed. The direct criterions for local stability of positive equilibrium and existence of limit cycle are also established when inference parameter of predator is small.

  17. 采用动态禁止角的动力定位系统推力分配策略%LI Bo, WANG Lei Thrust Allocation with Dynamic Forbidden Sectors in Dynamic Positioning System

    Institute of Scientific and Technical Information of China (English)

    李博; 王磊

    2014-01-01

    Thrust allocation is one component of dynamic positioning system, which allocates the thrusts generated by the control law among the thrusters. Generally, forbidden sectors are set in thrust allocation to prevent thrusters from entering certain azimuth angles in order to avoid large thrust loss on downstream thrusters. In this paper, a novel concept of dynamic forbidden sector is proposed. Based on the results of model test, the extent of forbidden sector could be adjusted according to the propellers’ speed ratio. This method could guarantee required safety. And numerical simulation in-dicates that thrust allocation could give more reasonable results after the introduction of dynamic forbidden sectors.%动力定位系统利用推力分配策略将总推力需求分配到多个推进器上。为了避免由推进器尾流造成的推进器之间的水动力干扰,通常会在推力分配策略中设置推进器回转方向的禁止角。全回转推进器水动力干扰试验的结果显示,推进器之间水动力干扰的程度前后随推进器的相对转速而变化。以模型试验的数据为基础,文章首次提出了动态禁止角的概念和数学模型。通过在推力分配策略中设置动态禁止角,回转方向的禁止角将随推进器的相对转速变化而进行调整,从而完全避免推进器之间的水动力干扰问题。动力定位系统的数值模拟结果显示新的推力分配策略可以给出更合理的分配结果。

  18. 基于PSO优化的船舶动力定位观测器%Nonlinear Observer for Dynamic Positioning Ships Based on PSO

    Institute of Scientific and Technical Information of China (English)

    谢业海; 徐慧璇

    2015-01-01

    Observer is important for dynamic positioning (DP) ship, and appropriate parameters of observer can improve the performance of DP. The parameters of the observer are optimized off-line using particle swarm optimization (PSO) in this paper, in order to obtain the accurate parameters of the nonlinear passive observer. The estimated error of observer is changed as the object function of PSO. Finally, the method is verified effective and can improve the performance of DP by the computer simulation.%观测器设计是船舶动力系统至关重要的一个环节,而观测器的参数选取是否合适对动力定位系统的性能将产生很大的影响。建立了船舶非线性无源观测器,为了快速获得精确的观测器参数,提出利用粒子群算法对观测器参数进行寻优,寻优过程中利用观测器的估计偏差作为粒子群的适应度函数。文章最后对参数优化的观测器进行了仿真验证,仿真结果表明优化后的观测器具有较小的估计偏差且能改善动力定位系统的性能。

  19. Calculation of Thrust Losses in Dynamic Positioning System%船舶动力定位系统推进器推力损失计算

    Institute of Scientific and Technical Information of China (English)

    广超越; 罗薇

    2012-01-01

    The formation mechanism of the thrust losses in Dynamic Positioning System (DPS) is discussed in this paper. Using semi-empirical methods based on model test, the total thrust losses caused by thruster-hull interaction, thruster-thruster interaction, the current, the wave and other factors are calculated. Having known the thruster parameters and configuration, the parameters of current and waves, the thrust losses are calculated when the thrusters of DPS produce thrust in 360 degree zone, thereby, the thrust losses diagram are figured out and analyzed. What's more, a new concept of forbidden zone in the thrust optimization distribution is proposed, and the measures of how to reduce thrust losses are also discussed.%阐述了船舶动力定位系统(DPS)推进器推力损失的形成机理,采用基于模型试验的半经验计算方法,对推进器与船体之间的相互干扰、推进器之间的相互干扰、海流、波浪等因素引起的推进器推力损失进行了计算.在已知推进器的参数和布置以及海流、波浪等环境载荷参数条件下,计算和分析了DPS推进器在360°的范围内产生推力时的推力损失图.针对计算结果提出了推力最优分配中设置禁区的概念,并对如何减小推力损失的措施进行了探讨.

  20. Application of GPS and Laser Ranging Dynamic Positioning System in some unreachable areas%GPS激光测距动态定位系统在无法到达区的应用研究

    Institute of Scientific and Technical Information of China (English)

    谭瑞; 章传银; 秘金钟; 杨强; 谷守周; 李源

    2013-01-01

    The method of positioning in some unreachable areas without the terrestrial control network was studied and GPS and Laser Ranging Dynamic Positioning System was developed in the paper. In order to verify the availability of this system on the water and in special dynamic survey and so on, the experiments of this system were developed on the land and water and the positioning accuracy was analyzed in the static and dynamic conditions. The result showed that it could implement the three dimensions positioning of unreachable objects quickly with outside fitting accuracy of less than 1 mete; the system was proved of easy operation, structural reliability, and steady performance.%本文研究了在无法到达区无地面控制网的目标定位方法,研制了GPS激光测距动态定位系统装备;开展了陆上、水面试验,分析了系统在静态/动态条件下的定位精度;验证了该系统在水上等特殊动态测量模式下的可用性,结果表明该系统可以快速对无法到达地区的目标点完成三维定位,外符合精度优于1m;系统操作方便,结构可靠,性能稳定.

  1. Position Information

    Data.gov (United States)

    Social Security Administration — The Position Information Data Asset provides the ability to search for active SSA position descriptions using various search criteria. An individual may search by PD...

  2. Positive Psychology

    Science.gov (United States)

    Peterson, Christopher

    2009-01-01

    Positive psychology is a deliberate correction to the focus of psychology on problems. Positive psychology does not deny the difficulties that people may experience but does suggest that sole attention to disorder leads to an incomplete view of the human condition. Positive psychologists concern themselves with four major topics: (1) positive…

  3. Complex positive maps and quaternionic unitary evolution

    Energy Technology Data Exchange (ETDEWEB)

    Asorey, M [Departamento de Fisica Teorica, Universidad de Zaragoza, 50009 Zaragoza (Spain); Scolarici, G [Dipartimento di Fisica dell' Universita di Lecce and INFN, Sezione di Lecce, I-73100 Lecce (Italy)

    2006-08-04

    The complex projection of any n-dimensional quaternionic unitary dynamics defines a one-parameter positive semigroup dynamics. We show that the converse is also true, i.e. that any one-parameter positive semigroup dynamics of complex density matrices with maximal rank can be obtained as the complex projection of suitable quaternionic unitary dynamics.

  4. Ubiquitous positioning

    CERN Document Server

    Mannings, Robin

    2008-01-01

    This groundbreaking resource offers a practical, in-depth understanding of Ubiquitous Positioning - positioning systems that identify the location and position of people, vehicles and objects in time and space in the digitized networked economy. The future and growth of ubiquitous positioning will be fueled by the convergence of many other areas of technology, from mobile telematics, Internet technology, and location systems, to sensing systems, geographic information systems, and the semantic web. This first-of-its-kind volume explores ubiquitous positioning from a convergence perspective, of

  5. Positioning consumption

    DEFF Research Database (Denmark)

    Halkier, Bente; Keller, Margit

    2014-01-01

    positionings emerges based on empirical examples of research in parent–children consumption. Positionings are flexible discursive fixations of the relationship between the performances of the practitioner, other practitioners, media discourse and consumption activities. The basic positioning types...... are the practice maintenance and the practice change position, with different sorts of adapting in between. Media discourse can become a resource for a resistant position against social control or for an appropriating position in favour of space for action. Regardless of the current relation to a particular media...... discourse, practitioners attempt to maintain their self-positioning of competence when performing. This leads us, as researchers, to caution against any a priori anticipation of the anchoring power of media discourses within everyday activities....

  6. Dynamics of the Macular Hole-Silicone Oil Tamponade Interface with Patient Positioning as Imaged by Spectral Domain Optical Coherence Tomography

    Science.gov (United States)

    Oster, Stephen F.; Mojana, Francesca; Bartsch, Dirk-Uwe G.; Goldbaum, Michael; Freeman, William R.

    2010-01-01

    Purpose To evaluate with spectral domain optical coherence tomography (SD-OCT) the relationship between the retina and overlying silicone oil tamponade after macular hole surgery, and to evaluate how this relationship changes with patient positioning. Patients and Methods Retrospective consecutive case series of 10 eyes from 9 patients who underwent macular hole surgery with silicone oil tamponade and subsequent SD-OCT scans. Four of the included eyes were also imaged with patients in face-down posture to determine if the silicone-retina apposition changes with prone positioning. Finally, a single patient was additionally scanned in the lateral and supine positions. Results The posterior surface of the silicone oil bubble was well visualized in all 10 eyes. In the majority of eyes (7/10) the oil tamponade bridged across the macular hole creating a pre-foveal fluid space, but in 3 eyes the silicone oil filled the macular hole and was seen in touch with the underlying foveal depression or retinal pigment epithelium. In 75% of eyes (3/4) the silicone oil-retinal approximation did not vary with face-down position. Supine positioning clearly floated the silicone tamponade anteriorly and off of the retinal surface. Conclusions Silicone oil tamponade can either bridge across macular holes, or in a novel finding, can fill the underlying foveal depression or macular hole space. Generally, the oil position is stable between face-forward and prone SD-OCT images, suggesting that either of these patient positions allows waterproofing of the underlying macular hole. Finally, our images confirm that supine positioning should be avoided post-operatively as it leads to loss of oil-retinal tamponade. PMID:20531144

  7. Research on the impact of one line failure for a mooring assisted dynamic positioning system%锚泊辅助动力定位系统单缆失效影响研究

    Institute of Scientific and Technical Information of China (English)

    张峰; 王磊; 李勇跃

    2012-01-01

    For a semi-submersible platform, one mooring line may fail when the mooring-assisted dynamic positioning system works in the sea. As an example, a semi-submersible platform has been considered and a mooring-assisted dynamic positioning system has been designed. By using the time domain simulation, the impact of one mooring line failure on the offsets and power utilization of the platform will be analyzed. From the analysis result, it is suggested that under severe conditions, loosing the tension of the leeward lines can reduce power consumption, improve positioning accuracy and the safety of the positioning system, which will be helpful to the further engineering applications of the mooring-assisted dynamic positioning system.%针对半潜式钻井平台锚泊辅助动力定位系统在海上作业时可能会出现的单缆失效情况.以一艘半潜式平台为例,设计锚泊辅助动力定位系统.通过全动态时域模拟,研究不同的单缆失效模式对半潜式平台锚泊辅助动力定位系统功率消耗、定位精度、缆绳张力等的影响.根据分析结果,在极端海况下,松弛锚泊辅助动力定位系统的背风缆有助于降低定位系统的功率消耗,提高定位精度和系统的安全性,从而为锚泊辅助动力定位系统的工程应用提供一些参考.

  8. 船舶动力定位系统的非线性输出反馈控制%Nonlinear Output Feedback Control of Dynamic Positioning System of Ships

    Institute of Scientific and Technical Information of China (English)

    杜佳璐; 李文华; 郑凯; 于双和

    2012-01-01

    针对动力定位船舶的速度不可测问题,考虑带有环境扰动的动力定位船舶运动非线性数学模型,提出一个非线性观测器-控制器控制方案,实现仅依赖于船舶位置和艏向测量值的船舶动力定位的输出反馈控制,且其观测器具有分离的稳定性.应用串级非线性系统理论证明了最终的船舶动力定位输出反馈闭环系统是全局渐近稳定的,所设计的输出反馈控制律迫使船舶的位置及艏摇角全局渐近收敛于期望值.以一艘供给船为例进行仿真研究,结果验证了所设计的船舶动力定位输出反馈控制律的有效性.%In order to overcome the non-measurability of the velocity of dynamic positioning ships, a nonlinear observer-controller scheme with separate stability for the observer is proposed based on the nonlinear mathematical model of ship movement with environmental disturbances. The proposed scheme implements the output feedback control of ship dynamic positioning systems with position and orientation measurements only. The resulting output feedback closed-loop control system of dynamic positioning ships is proved to be globally and asymptotically stable by applying the cascaded nonlinear system theory, and the designed output feedback control law forces the ship position and orientation to globally and asymptotically converge to their desired values. Simulation results on a supply ship verify the effectiveness of the proposed output control law for the dynamic positioning of ships.

  9. Positive Psychotherapy

    Science.gov (United States)

    Seligman, Martin E. P.; Rashid, Tayyab; Parks, Acacia C.

    2006-01-01

    Positive psychotherapy (PPT) contrasts with standard interventions for depression by increasing positive emotion, engagement, and meaning rather than directly targeting depressive symptoms. The authors have tested the effects of these interventions in a variety of settings. In informal student and clinical settings, people not uncommonly reported…

  10. Clinical Positioning Space

    DEFF Research Database (Denmark)

    Williams, Lars Peter Hedegaard; Christensen, Mette Krogh; Rytter, Carsten

    2014-01-01

    In this article, we present a case study of residents’ clinical experiences and communication in outpatient oncology consultations. We apply positioning theory, a dynamic alternative to role theory, to investigate how oncology residents and patients situate themselves as persons with rights...... establish acts and positions and narratively frame what participants can expect from a medical consultation viewed as a social episode; and (c) the positioning of rights and duties can lead to misunderstandings and frustrations. We conclude that residents and patients locate themselves in outpatient...

  11. The Dynamic Relationship Between Cognitive Function and Positive Well-Being in Older People: A Prospective Study Using the English Longitudinal Study of Aging

    Science.gov (United States)

    2014-01-01

    There is evidence that having a stronger sense of positive well-being may be a potential resource for healthier aging as represented by slower physical decline, reduced risk of frailty and longer survival. However, it is unclear whether positive well-being is protective of another crucial component of healthy aging, cognitive function, or whether it has a bidirectional relationship with cognitive function. We use multilevel models with within-person centering to estimate the within- and between-person association between cognitive function and positive well-being in 4 waves of data from the English Longitudinal Study of Ageing (ELSA), (N = 10985, aged 50–90 years at wave 1). Our findings show that, although most variation in cognitive function was explained by age, and most variation in well-being was explained by depression, small but significant associations between cognition and well-being remained after variation in age and depression were controlled. In models where cognition was the outcome, the association was mainly because of variation in mean levels of well-being between persons. In models where well-being was the outcome, the association was mainly because of within-person fluctuation in cognitive test performance. Exercise and depression were the most important moderating influences on the association between cognition and positive well-being. Depression had greater effect upon this association for those with higher well-being, but exercise protected cognitive performance against the adverse effects of lower well-being. PMID:24955999

  12. Positioning Agility

    Science.gov (United States)

    Oza, Nilay; Abrahamsson, Pekka; Conboy, Kieran

    Agile methods are increasingly adopted by European companies. Academics too are conducting numerous studies on different tenets of agile methods. Companies often feel proud in marketing themselves as ‘agile’. However, the true notion of ‘being agile’ seems to have been overlooked due to lack of positioning of oneself for agility. This raises a call for more research and interactions between academia and the industry. The proposed workshop refers to this call. It will be highly relevant to participants, interested in positioning their company’s agility from organizational, group or project perspectives. The positioning of agility will help companies to better align their agile practices with stakeholder values. Results of the workshop will be shared across participants and they will also have opportunity to continue their work on agile positioning in their companies. At broader level, the work done in this workshop will contribute towards developing Agile Positioning System.

  13. Researcher positioning

    DEFF Research Database (Denmark)

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...

  14. Researcher positioning

    DEFF Research Database (Denmark)

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...... process. Studying the other calls for close reflections on one's own position, theoretically, personally, and politically, taking into account one's complicity in either overcoming or reproducing processes of othering and marginalisation. [i] We use the term (ethnic) minoritised, not as a distinction...

  15. 动力定位船舶纵向运动的反步法控制器设计%Backstepping Controller Design for Dynamic Positioning Ship of Vertical Motion

    Institute of Scientific and Technical Information of China (English)

    张晓兰; 王钦若; 时丽丽

    2011-01-01

    本文研究了动力定位系统的控制策略,针对船舶动力定位系统模型的非线性特性,考虑到风浪流等外部环境扰动对船舶引起的恒值干扰及其不确定性,基于带有未知定常扰动的三自由度非线性船舶水面运动数学模型,应用自适应反步法设计船舶动力定位控制律,将Lyapunov函数选取和控制器设计相结合的回归设计方法,并在MATLAB软件环境下通过仿真研究验证模型和控制策略的有效性。在计算机仿真研究中,以26:1比例建造的2800mm×762mm×498mm船模为设计实例。%This paper discusses the control strategy of dynamic positioning system. For the nonlinear characteristics of dynamic positioning system model, the paper takes constant interference of ship and its uncertainty caused by external disturbances such as the wind, waves and current into account. Based on the stationary disturbance with unknown three degrees of freedom nonlinear ship motion mathematical surface model, we apply adaptive backstepping control law for the nonlinear dynamic positioning. The selection of Lyapunov function and the controller design are combined with regression. The control strategy and mathematical model are proved to be effective with the MATLAB simulation. The design example is a 2800mm×762mm×498mm ship model with 26:1 ratio.

  16. SRI-VC2110DP动力定位系统水池试验研究%Research on Pool Test of SRI-VC2110DP Dynamic Positioning System

    Institute of Scientific and Technical Information of China (English)

    许安静; 韩冰; 董胜利

    2012-01-01

    SRI—VC2110DP动力定位系统是由上海船舶运输科学研究所自主研发的全新深海动力定位产品。针对该系统的主要功能、控制精度以及控制稳定性等技术指标的检测问题,根据目标船的实际工作情况,对该动力定位系统的水池试验进行设计,并完成了系统主要功能测试。在不同模拟环境下的试验结果表明,SRI—VC2110DP动力定位系统能够满足目标船对动力定位控制系统的技术要求,并且具有良好的控制精度和稳定性。%SRI-VC2110DP dynamic positioning (DP) system is independently developed by of the Shanghai Ship and Shipping Research Institute and it is a new product for ocean engineering. For the examination of the system function, control accuracy and control stability, a pool test of the dynamic positioning system is designed and completed based on the actual situation of the target ship in this paper. The test results with different simulated environment show that the SRI-VC2110DP dynamic posi-tioning system is meet to the technical requirements of the target ship with good control accuracy and stability.

  17. Integrated Monitoring Technology of Dynamic Positioning in Semi-submersible Drilling Platform%半潜式钻井平台动力定位集成监控技术

    Institute of Scientific and Technical Information of China (English)

    高文; 陈红卫

    2011-01-01

    针对目前海洋钻井信息管理平台中集成能力、可操作性和可扩展性存在的问题,研究了半潜式钻井平台动力定位集成监控技术;介绍了钻井平台动力定位系统组成和信息集成技术;设计了监控系统网络结构和软件结构;应用OPC技术设计客户端解决了网络异构问题,实现了钻井平台动力定位集成监控;最后利用PLC模拟了吊舱和柴油发电机数据环境,对OPC客户端进行了测试;测试结果表明,客户端能够与不同服务器建立连接,实现对不同系统、设备数据的读写.%Specifically for solving the problems of offshore drilling information management platform such as integrated ability, operabili-ty and extensibility, the integrated monitoring technology of dynamic positioning in semi -submersible drilling platform is studied. Not only integrated technology and dynamic positioning system are introduced, but also network architecture and software architecture are designed. Designing client based on OPC technology solves the problem of heterogeneous networks to achieve integrated monitoring for dynamic positioning system of Semi - submersible drilling platform. Finally using PLC simulates data environment of pod and diesel generator to test client. The results show that the client can connect with different servers and exchange data with different systems and equipments.

  18. 动力定位船舶自适应滑模无源观测器设计%Adaptive sliding-mode passive observer design for dynamic positioning vessel

    Institute of Scientific and Technical Information of China (English)

    谢文博; 付明玉; 施小成

    2013-01-01

    针对带有模型参数不确定性的动力定位船舶,提出一种动力定位船全速域自适应滑模无源观测器,解决了现有观测器只能应用于低速作业动力定位系统的问题.采用速度估计误差作为滑模面,设计切换自适应律估计模型不确定项上界,保证了观测器增益的有界性和系统鲁棒性.对速度估计回路的无源性进行了分析,并证明了观测器的稳定性.最后利用船舶动力定位系统半实物仿真平台,验证了算法的有效性.%Because the existing observers can only be applied to low-speed dynamic positioning systems, we propose an adaptive sliding-mode passive observer for all speed envelopes of the dynamic positioning vessel with uncertain model parameters. The velocity estimation error is used as the sliding-mode surface; a switching adaptive update law is designed to estimate the upper bound of model uncertainties for restricting the observer gains and improving the robustness of the system. The passivity analysis of the loop for speed estimation is given; the stability of the observer is proved. The algorithm is validated through a hardware-in-the-loop simulation of a dynamic positioning system.

  19. Application of dynamic positioning system in multi purpose seagoing tender%动力定位系统在多用途海洋供应船上的应用

    Institute of Scientific and Technical Information of China (English)

    黄栋梁

    2008-01-01

    船舶动力定位系统(Dynamic Positioning Systems,简称DP)是现代计算机技术和自动化控制理论的完美结合.运用DP系统除能完成海上石油平台补给、海底电缆铺设和检修、打捞救生等作业外,还可在复杂的海况下完成海上船舶间运动补给和科学考察等高难动作.

  20. The efficient model to define a single light source position by use of high dynamic range image of 3D scene

    Science.gov (United States)

    Wang, Xu-yang; Zhdanov, Dmitry D.; Potemin, Igor S.; Wang, Ying; Cheng, Han

    2016-10-01

    One of the challenges of augmented reality is a seamless combination of objects of the real and virtual worlds, for example light sources. We suggest a measurement and computation models for reconstruction of light source position. The model is based on the dependence of luminance of the small size diffuse surface directly illuminated by point like source placed at a short distance from the observer or camera. The advantage of the computational model is the ability to eliminate the effects of indirect illumination. The paper presents a number of examples to illustrate the efficiency and accuracy of the proposed method.

  1. Comparison of the upper airway dynamics of oronasal and nasal masks with positive airway pressure treatment using cine magnetic resonance imaging.

    Science.gov (United States)

    Ebben, Matthew R; Milrad, Sara; Dyke, Jonathan P; Phillips, C Douglas; Krieger, Ana C

    2016-03-01

    It is known that oronasal masks are not as effective at opening the upper airway compared to nasal only continuous positive airway pressure (CPAP) masks in patients with sleep-disordered breathing. However, the physiological mechanism for this difference in efficacy is not known; although, it has been hypothesized to involve the retroglossal and/or retropalatal region of the upper airway. The objective of this study was to investigate differences in retroglossal and retropalatal anterior-posterior space with the use of oronasal vs. nasal CPAP masks using real-time cine magnetic resonance imaging (cMRI). Ten subjects (eight men, two women) with obstructive sleep apnea (OSA) were given cMRI with both nasal and oronasal CPAP masks. Each subject was imaged with each interface at pressures of 5, 10, and 15 cm of H2O, while in the supine position along the sagittal plane. The oronasal mask produced significantly less airway opening in the retropalatal region of the upper airway compared to the nasal mask interface. During exhalation, mask style had a significant effect on anterior-posterior distance p = 0.016. No differences were found in the retroglossal region between mask styles. Our study confirmed previous findings showing differences in treatment efficacy between oronasal and nasal mask styles. We have shown anatomic evidence that the nasal mask is more effective in opening the upper airway compared to the oronasal mask in the retropalatal region.

  2. Positional games

    CERN Document Server

    Hefetz, Dan; Stojaković, Miloš; Szabó, Tibor

    2014-01-01

    This text serves as a thorough introduction to the rapidly developing field of positional games. This area constitutes an important branch of combinatorics, whose aim it is to systematically develop an extensive mathematical basis for a variety of two-player perfect information games. These range from such popular games as Tic-Tac-Toe and Hex to purely abstract games played on graphs and hypergraphs. The subject of positional games is strongly related to several other branches of combinatorics such as Ramsey theory, extremal graph and set theory, and the probabilistic method. These notes cover a variety of topics in positional games, including both classical results and recent important developments. They are presented in an accessible way and are accompanied by exercises of varying difficulty, helping the reader to better understand the theory. The text will benefit both researchers and graduate students in combinatorics and adjacent fields.

  3. 动力定位系统故障模式与后果分析中的关键点%Key Elements of Failure Mode and Effect Analysis for Dynamic Positioning System

    Institute of Scientific and Technical Information of China (English)

    刘潇; 冯舒

    2012-01-01

    Position loss is the main risk of the application of Dynamic Positioning (DP) system in offshore industry. To avoid position loss accident, DP reliability is achieved through the redundancy design of the system. Major classification societies require a Failure Mode and Effect Analysis (FMEA) to be performed to verify the redundancy of the DP system. Level of details and quality of the FMEA work directly affects the reliability design of the system. This paper introduces the DP FMEA methodology and discusses the key elements of DP FMEA with examples. Recommendations are also proposed accordingly to include industry best practice in the future DP FMEA work.%移位风险是动力定位(Dynamic Positioning,简称DP)系统在海洋工程领域应用过程中的最主要风险,设计中通过采用较高级别的冗余度提高系统的可靠性,避免移位事故的发生.各大船级社都要求通过故障模式与后果分析(Failure Mode and Effect Analysis,简称FMEA)的方式对动力定位系统的冗余度进行验证,分析的深度和质量直接关系到动力定位系统的可靠性设计.本文介绍了DP FMEA分析方法,并通过实例讨论了成功开展DP FMEA分析的几个关键点,为未来开展类似的工作提出相关建议.

  4. Researcher Positioning

    DEFF Research Database (Denmark)

    Khawaja, Iram; Mørck, Line Lerche

    2009-01-01

    This article focuses on the complex and multilayered process of researcher positioning,specifically in relation to the politically sensitive study of marginalised and "othered"groups such as Muslims living in Denmark. We discuss the impact of different ethnic,religious, and racial backgrounds...... involvement by the researcher, which challenges traditional perspectives onresearch and researcher positioning. A key point in this regard is the importance ofconstant awareness of and reflection on the multiple ways in which one's positioningas a researcher influences the research process. Studying the other...

  5. Infection Dynamics and Antimicrobial Resistance Profile of Salmonella Paratyphi B d-tartrate Positive (Java) in a Persistently Infected Broiler Barn.

    Science.gov (United States)

    Kloska, Franziska; Beyerbach, Martin; Klein, Günter

    2017-01-21

    The infection dynamics of S. Java were examined in three consecutive rearing periods on a broiler farm in Northwestern Germany which had been persistently infected with S. Java for more than five years. The barn was investigated for Salmonella occurrence after cleaning and disinfection to verify the persistent contamination of the broiler house with S. Java before the start of the first rearing cycle. Confirmation of Salmonella absence in day-old chicks (time-point 1) as well as early establishment of infection between days 5-7 (time-point 2) were confirmed by caecal swabs prepared for qPCR and classical microbiological methods. At three time-periods (between days 11-15 (time-point 3), days 25-28 (time-point 4), and days 38-40 (time-point 5)) caecal content was examined for colony forming units (CFU) Salmonella/g. In general, there was an increase in Salmonella Java load at time-point 4 compared to time-points 3 and 5. Therefore, we observed a bell-shaped course of infection resulting in higher rates of Salmonella CFU/g prior to prethinning than at final slaughter. The antimicrobial susceptibility testing revealed resistance to tetracycline, fluorquinolones, trimethoprim, and cefoxitin.

  6. Infection Dynamics and Antimicrobial Resistance Profile of Salmonella Paratyphi B d-tartrate Positive (Java) in a Persistently Infected Broiler Barn

    Science.gov (United States)

    Kloska, Franziska; Beyerbach, Martin; Klein, Günter

    2017-01-01

    The infection dynamics of S. Java were examined in three consecutive rearing periods on a broiler farm in Northwestern Germany which had been persistently infected with S. Java for more than five years. The barn was investigated for Salmonella occurrence after cleaning and disinfection to verify the persistent contamination of the broiler house with S. Java before the start of the first rearing cycle. Confirmation of Salmonella absence in day-old chicks (time-point 1) as well as early establishment of infection between days 5–7 (time-point 2) were confirmed by caecal swabs prepared for qPCR and classical microbiological methods. At three time-periods (between days 11–15 (time-point 3), days 25–28 (time-point 4), and days 38–40 (time-point 5)) caecal content was examined for colony forming units (CFU) Salmonella/g. In general, there was an increase in Salmonella Java load at time-point 4 compared to time-points 3 and 5. Therefore, we observed a bell-shaped course of infection resulting in higher rates of Salmonella CFU/g prior to prethinning than at final slaughter. The antimicrobial susceptibility testing revealed resistance to tetracycline, fluorquinolones, trimethoprim, and cefoxitin. PMID:28117713

  7. Effect of initial ion positions on the interactions of monovalent and divalent ions with a DNA duplex as revealed with atomistic molecular dynamics simulations.

    Science.gov (United States)

    Robbins, Timothy J; Wang, Yongmei

    2013-01-01

    Monovalent (Na(+)) and divalent (Mg(2+)) ion distributions around the Dickerson-Drew dodecamer were studied by atomistic molecular dynamics (MD) simulations with AMBER molecular modeling software. Different initial placements of ions were tried and the resulting effects on the ion distributions around DNA were investigated. For monovalent ions, results were found to be nearly independent of initial cation coordinates. However, Mg(2+) ions demonstrated a strong initial coordinate dependent behavior. While some divalent ions initially placed near the DNA formed essentially permanent direct coordination complexes with electronegative DNA atoms, Mg(2+) ions initially placed further away from the duplex formed a full, nonexchanging, octahedral first solvation shell. These fully solvated cations were still capable of binding with DNA with events lasting up to 20 ns, and in comparison were bound much longer than Na(+) ions. Force field parameters were also investigated with modest and little differences arising from ion (ions94 and ions08) and nucleic acid description (ff99, ff99bsc0, and ff10), respectively. Based on known Mg(2+) ion solvation structure, we conclude that in most cases Mg(2+) ions retain their first solvation shell, making only solvent-mediated contacts with DNA duplex. The proper way to simulate Mg(2+) ions around DNA duplex, therefore, should begin with ions placed in the bulk water.

  8. Dynamics of selected MHC class I and II molecule expression in the course of HPV positive CIN treatment with the use of human recombinant IFN-gamma.

    Science.gov (United States)

    Sikorski, Marek; Bobek, Malgorzata; Zrubek, HenryK; Marcinkiewicz, Janusz

    2004-03-01

    Studies consistently reveal downregulation of major histocompatibility complex (MHC)-I molecules or/and selective loss of individual MHC-I alleles and upregulation of MHC-II molecules in the areas of cervical intraepithelial neoplasia (CIN) and in cervical cancers. In vitro studies demonstrated the interferon-gamma (IFN-gamma) potential of MHC class I and II molecule upregulation followed by increased cytolytic response against some cervical cancer cell lines. In vivo assessment of the correlation between regression/persistence state of CIN and the IFN-gamma-induced changes in both class of selected MHC molecule expression. Seventeen subjects with CIN I/CIN II associated with high-risk HPV infection underwent uniform IFN-gamma treatment (four intracervical injections over 2-day interval for a total dose of 6,000,000 IU). Immunohistochemical staining has been performed within cervical punch biopsy specimens with the use of monoclonal antibody reacting with HLA-DR, HLA-HC and HLA-Bw4, and the mean proportion of given molecules expressing keratinocytes was counted before, immediately after and 2 months after IFN-gamma treatment The analysis revealed a rapid and significant increase of the HLA-Bw4 proportion in response to IFN-gamma, persistent in the group of complete responders (with CIN clearance). No significant changes in the proportion of HLA-HC 10 positive cells in response to IFN-gamma administration was demonstrated, nor a significant increase in HLA-DR positivity; however, the transient trend towards increasing the proportion of HLA-DR immediately after treatment completion was observed. Upregulation of selected MHC class I allele expression, but not necessary MHC class II or heavy chain fragments of MHC-I, induced by IFN-gamma correlates with the resolution of cervical intraepithelial lesions and high-risk HPV DNA clearance in vivo.

  9. Positively Adolescent!

    Science.gov (United States)

    Williamson, Sue

    2000-01-01

    Believes that music teachers should reassess their views toward adolescent behavior in the music classroom by learning to see their behavior in a positive light. Describes teaching strategies that build on four adolescent behaviors: (1) desire for peer acceptance; (2) abundant energy; (3) love of fun; and (4) limited time-managing skills. (CMK)

  10. What controls nucleosome positions?

    Science.gov (United States)

    Segal, Eran; Widom, Jonathan

    2009-08-01

    The DNA of eukaryotic genomes is wrapped in nucleosomes, which strongly distort and occlude the DNA from access to most DNA-binding proteins. An understanding of the mechanisms that control nucleosome positioning along the DNA is thus essential to understanding the binding and action of proteins that carry out essential genetic functions. New genome-wide data on in vivo and in vitro nucleosome positioning greatly advance our understanding of several factors that can influence nucleosome positioning, including DNA sequence preferences, DNA methylation, histone variants and post-translational modifications, higher order chromatin structure, and the actions of transcription factors, chromatin remodelers and other DNA-binding proteins. We discuss how these factors function and ways in which they might be integrated into a unified framework that accounts for both the preservation of nucleosome positioning and the dynamic nucleosome repositioning that occur across biological conditions, cell types, developmental processes and disease.

  11. Fractional {sup 13}C enrichment of isolated carbons using [1-{sup 13}C]- or [2-{sup 13}C]-glucose facilitates the accurate measurement of dynamics at backbone C{sup {alpha}} and side-chain methyl positions in proteins

    Energy Technology Data Exchange (ETDEWEB)

    Lundstroem, Patrik [University of Toronto, Departments of Medical Genetics and Chemistry (Canada); Teilum, Kaare; Carstensen, Tommy [Lund University, Department of Biophysical Chemistry (Sweden); Bezsonova, Irina [University of Toronto, Department of Chemistry (Canada); Wiesner, Silke [University of Toronto, Department of Biochemistry (Canada); Hansen, D. Flemming [University of Toronto, Departments of Medical Genetics and Chemistry (Canada); Religa, Tomasz L. [Medical Research Council Centre for Protein Engineering (United Kingdom); Akke, Mikael [Lund University, Department of Biophysical Chemistry (Sweden); Kay, Lewis E. [University of Toronto, Departments of Medical Genetics and Chemistry (Canada)], E-mail: kay@pound.med.utoronto.ca

    2007-07-15

    A simple labeling approach is presented based on protein expression in [1-{sup 13}C]- or [2-{sup 13}C]-glucose containing media that produces molecules enriched at methyl carbon positions or backbone C{sup {alpha}} sites, respectively. All of the methyl groups, with the exception of Thr and Ile({delta}1) are produced with isolated {sup 13}C spins (i.e., no {sup 13}C-{sup 13}C one bond couplings), facilitating studies of dynamics through the use of spin-spin relaxation experiments without artifacts introduced by evolution due to large homonuclear scalar couplings. Carbon-{alpha} sites are labeled without concomitant labeling at C{sup {beta}} positions for 17 of the common 20 amino acids and there are no cases for which {sup 13}C{sup {alpha}}-{sup 13}CO spin pairs are observed. A large number of probes are thus available for the study of protein dynamics with the results obtained complimenting those from more traditional backbone {sup 15}N studies. The utility of the labeling is established by recording {sup 13}C R{sub 1{rho}} and CPMG-based experiments on a number of different protein systems.

  12. “海洋石油278”动力定位系统升级后推进器舱布置方案设计%Propeller Room Arrangement Design for Dynamic Positioning System Upgrade of HYSY-278

    Institute of Scientific and Technical Information of China (English)

    邱波; 李东芳; 张永发

    2014-01-01

    In order to improve the dynamic positioning capability of HYSY-278, the DP-2 dynamic positioning system of the boat was upgraded to DP-3.The original arrangement of the propeller room was planned and adjusted to satisfy the requirement of DP-3 redundant design according to the requirement of CCS .The A60 fire-proof walls were arranged among the propeller rooms .%介绍“海洋石油278”船从DP-2动力定位系统升级至DP-3动力定位系统后,推进器舱室的布置方案设计。为满足DP-3动力定位系统对推进器舱的冗余设计要求,根据CCS规范要求,对该船推进器舱的布置方案重新进行规划和调整,在冗余的推进器舱室之间设置A60防火墙。

  13. 船舶动力定位海浪环境的实时仿真与海浪谱分析%Real-time Simulation and Spectrum-Analisis of a Dynamic Positioning System Ship in Waves

    Institute of Scientific and Technical Information of China (English)

    王立军; 陈锋; 丁福光; 施小成

    2001-01-01

    提出一种根据随机海浪频谱来实时模拟随机海浪的方法,它可以用于研究动力定位船舶及其 控制系统在不同海况时的性能。该方法可以采用多种海浪谱来进行随机海浪的仿真。仿真结果利用了 快速傅立叶变换FFT(Fast Fourier Transform)进行频谱分析。仿真程序可用于实际的动力定位船舶系 统。%Provides a way to simulate waves in real-time according to random-wave-spectrum. It can be used to study the performances of dynamic positioning ship and control system under different waves. This method adapts several kinds of wave-spectrum to simulate waves. The results of simulation apply FFT(Fast Fourier Transform) to analyse the spectrum. The program has been applied to DPS (Dynamic Positioning System) ships.

  14. Dynamic Positioning at Sea Using the Global Positioning System.

    Science.gov (United States)

    1987-06-01

    recorded on digital cassettes in a format not directly compatible with the existing programs at NPS. To read and decode the data, it was necessary to...Lisboa Codex, Portugal 26. Biblioteca do I instituto Hidrografico Rua das Trinas, 49 1296 Lisboa Codex, Portugal 27. D.S.I.T. I Edificio da Administraqao

  15. 蒙古栎不同冠层部位叶片养分动态%Nutrient dynamics in Quercus mongolica leaves at different canopy positions

    Institute of Scientific and Technical Information of China (English)

    程徐冰; 韩士杰; 张忠辉; 周玉梅; 王树起; 王学娟

    2011-01-01

    以长白山原始针阔叶混交林优势树种蒙古栎为对象,研究了6-10月生长季不同冠层叶片单位叶面积质量(LMA)、单位质量和单位叶面积的C、N、P含量变化,以及N、P的再吸收效率与利用效率.结果表明:在生长季,蒙古栎冠层上、下部叶片的LMA和单位叶面积C含量(Carea)表现出明显的月动态变化;单位叶面积N、P含量(Narea、Parea)的月变化趋势与单位质量N、P含量(Nmass、Pmass)相似,而用单位叶面积与单位质量表示的N、P再吸收效率无明显差异.冠层位置对N的再吸收效率和利用效率无明显影响,但冠层上部P的再吸收效率和利用效率显著高于冠层下部.在未来气候变化情景下,蒙古栎较高的生存力和竞争力有助于促进生态系统的养分循环.%Taking the dominant tree species Quercus mongolica in natural coniferous-broadleaved mixed forest in Changbai Mountains as test object, this paper studied the variations of leaf dry mass per unit area ( LMA), leaf carbon (C), nitrogen ( N), and phosphorus ( P) contents per unit mass and per unit area, as well as the leaf N and P resorption efficiency and use efficiency at upper and lower canopy positions during growth season (from June to October). In the growth season, and at both upper and lower canopy positions, the LMA and leaf C content per unit area had obvi-ous monthly fluctuation, the leaf N and P contents per unit area had the similar monthly variation trend with the leaf N and P contents per unit mass, but the leaf N and P resorption efficiency per unit mass had no significant difference with the leaf N and P resorption efficiency per unit area. The leaf N resorption efficiency and use efficiency were less affected by canopy position, but the leaf P resorption efficiency and use efficiency were higher at upper canopy than at lower canopy. Under the scenario of future climate change, the higher survival and competitive capabilities of Q. mongol-ica would

  16. Analysis on the influence of thruster failure mode for a mooring assisted dynamic positioning system%锚泊辅助动力定位系统推力器故障模式影响分析

    Institute of Scientific and Technical Information of China (English)

    王洪超; 王磊; 张峰

    2013-01-01

    Mooring assisted dynamic positioning system is a new positioning system including mooring system and dynamic positioning system. With a certain deep water semi-submersible drilling platform as its subject, this paper is dedicated to exploring the influence of two thrusters' failure mode on the offset, power consumption and top tension of the mooring line of the platform using time domain simulation method. The results indicate that two thrusters' failure of the same switchboard may cause a remarkable impact on the offset of the platform. Thus, it is suggested that the forbidden angle of the thrusters adjacent to the failed thrusters should be cancelled, weather mooring lines be tightened and leeward mooring lines be loosed. The suggestion can reduce the offset and consumed power of the platform and may be helpful to the FMEA of dynamic positioning system.%锚泊辅助动力定位是将锚泊定位和动力定位相结合的一种新型位置控制系统.以某深水半潜式钻井平台为例,通过时域模拟分析了两个推力器失效模式对平台锚泊辅助动力定位系统定位精度、功率消耗及缆绳张力的影响.分析结果可以看出,深水作业时平台同一配电板上两推力器失效对平台水平偏移有很大影响,可通过减小或取消失效推力器相邻推力器的禁止角及拉紧迎风缆并松弛背风缆的方法来减小平台偏移,节约功耗,为动力定位系统的故障模式与影响分析提供了参考.

  17. Dynamics of Adrenal Steroids Are Related to Variations in Th1 and Treg Populations during Mycobacterium tuberculosis Infection in HIV Positive Persons

    Science.gov (United States)

    Quiroga, Maria Florencia; Angerami, Matias Tomas; Santucci, Natalia; Ameri, Diego; Francos, Jose Luis; Wallach, Jorge; Sued, Omar; Cahn, Pedro; Salomón, Horacio; Bottasso, Oscar

    2012-01-01

    Tuberculosis (TB) remains the most frequent cause of illness and death from an infectious agent, and its interaction with HIV has devastating effects. We determined plasma levels of dehydroepiandrosterone (DHEA), its circulating form DHEA-suphate (DHEA-s) and cortisol in different stages of M. tuberculosis infection, and explored their role on the Th1 and Treg populations during different scenarios of HIV-TB coinfection, including the immune reconstitution inflammatory syndrome (IRIS), a condition related to antiretroviral treatment. DHEA levels were diminished in HIV-TB and HIV-TB IRIS patients compared to healthy donors (HD), HIV+ individuals and HIV+ individuals with latent TB (HIV-LTB), whereas dehydroepiandrosterone sulfate (DHEA-s) levels were markedly diminished in HIV-TB IRIS individuals. HIV-TB and IRIS patients presented a cortisol/DHEA ratio significantly higher than HIV+, HIV-LTB and HD individuals. A positive correlation was observed between DHEA-s and CD4 count among HIV-TB individuals. Conversely, cortisol plasma level inversely correlated with CD4 count within HIV-TB individuals. M. tuberculosis-specific Th1 lymphocyte count was increased after culturing PBMC from HIV-TB individuals in presence of DHEA. We observed an inverse correlation between DHEA-s plasma level and Treg frequency in co-infected individuals, and CD4+FoxP3+ Treg frequency was increased in HIV-TB and IRIS patients compared to other groups. Strikingly, we observed a prominent CD4+CD25-FoxP3+ population across HIV-TB and HIV-TB IRIS patients, which frequency correlated with DHEA plasma level. Finally, DHEA treatment negatively regulated FoxP3 expression without altering Treg frequency in co-infected patients. These data suggest an enhancing role for DHEA in the immune response against M. tuberculosis during HIV-TB coinfection and IRIS. PMID:22431997

  18. Dynamics of adrenal steroids are related to variations in Th1 and Treg populations during Mycobacterium tuberculosis infection in HIV positive persons.

    Directory of Open Access Journals (Sweden)

    Maria Florencia Quiroga

    Full Text Available Tuberculosis (TB remains the most frequent cause of illness and death from an infectious agent, and its interaction with HIV has devastating effects. We determined plasma levels of dehydroepiandrosterone (DHEA, its circulating form DHEA-suphate (DHEA-s and cortisol in different stages of M. tuberculosis infection, and explored their role on the Th1 and Treg populations during different scenarios of HIV-TB coinfection, including the immune reconstitution inflammatory syndrome (IRIS, a condition related to antiretroviral treatment. DHEA levels were diminished in HIV-TB and HIV-TB IRIS patients compared to healthy donors (HD, HIV+ individuals and HIV+ individuals with latent TB (HIV-LTB, whereas dehydroepiandrosterone sulfate (DHEA-s levels were markedly diminished in HIV-TB IRIS individuals. HIV-TB and IRIS patients presented a cortisol/DHEA ratio significantly higher than HIV+, HIV-LTB and HD individuals. A positive correlation was observed between DHEA-s and CD4 count among HIV-TB individuals. Conversely, cortisol plasma level inversely correlated with CD4 count within HIV-TB individuals. M. tuberculosis-specific Th1 lymphocyte count was increased after culturing PBMC from HIV-TB individuals in presence of DHEA. We observed an inverse correlation between DHEA-s plasma level and Treg frequency in co-infected individuals, and CD4+FoxP3+ Treg frequency was increased in HIV-TB and IRIS patients compared to other groups. Strikingly, we observed a prominent CD4+CD25-FoxP3+ population across HIV-TB and HIV-TB IRIS patients, which frequency correlated with DHEA plasma level. Finally, DHEA treatment negatively regulated FoxP3 expression without altering Treg frequency in co-infected patients. These data suggest an enhancing role for DHEA in the immune response against M. tuberculosis during HIV-TB coinfection and IRIS.

  19. Dynamics of C-reactive protein and white blood cell count in critically ill patients with nosocomial Gram positive vs. Gram negative bacteremia: a historical cohort study

    Directory of Open Access Journals (Sweden)

    Depuydt Pieter O

    2007-09-01

    Full Text Available Abstract Background Nosocomial bacteremia is associated with a poor prognosis. Early adequate therapy has been shown to improve outcome. Consequently, rapid detection of a beginning sepsis is therefore of the utmost importance. This historical cohort study was designed to evaluate if different patterns can be observed in either C-reactive protein (CRP and white blood cell count (WCC between Gram positive bacteremia (GPB vs. Gram negative bacteremia (GNB, and to assess the potential benefit of serial measurements of both biomarkers in terms of early antimicrobial therapy initiation. Methods A historical study (2003–2004 was conducted, including all adult intensive care unit patients with a nosocomial bacteremia. CRP and WCC count measurements were recorded daily from two days prior (d-2 until one day after onset of bacteremia (d+1. Delta (Δ CRP and Δ WCC levels from the level at d-2 onward were calculated. Results CRP levels and WCC counts were substantially higher in patients with GNB. Logistic regression analysis demonstrated that GNB and Acute Physiology and Chronic Health Evaluation (APACHE II score were independently associated with a CRP increase of 5 mg/dL from d-2 to d+1, and both were also independently associated with an increase of WCC levels from d-2 to d+1 of 5,000 × 103 cells/mm3. Conclusion Increased levels of CRP and WCC are suggestive for GNB, while almost unchanged CRP and WCC levels are observed in patients with GPB. However, despite the different patterns observed, antimicrobial treatment as such cannot be guided based on both biomarkers.

  20. 基于模型预测的动力定位控制系统体系结构及仿真%Framework and simulation of dynamic positioning control system based on model prediction

    Institute of Scientific and Technical Information of China (English)

    王卓; 陈红丽; 王芳; 万磊

    2013-01-01

    以“981”深海半潜式钻井平台为研究对象,根据国际海事组织和各大船级社对动力定位系统的安全规范要求,进行了DP-3级动力定位控制系统的总体方案设计.首先详细阐述了动力定位控制系统的硬件组成和结构及软件功能和层次,然后给出了平台的低频运动方程及基于模型预测的控制算法和控制器的具体设计方案及参数设置方法.最后建立了半实物仿真系统,进行了平台的作业工况和待机工况的动态模拟,通过仿真实验调试和验证了系统的硬件设备和软件方法.%According to the safety specification requirement for deepsea dynamic positioning system assigned by the International Maritime Organization and classification societies,taking the "981" deepsea semi-submersible drilling rig as the study object,the overall scheme of the DP-3 dynamic positioning control system was designed and developed.At first,the hardware composition and structure as well as the software function and hierarchy are described in detail.And then,the low-frequency dynamic equation of the rig is established.The model prediction based control algorithm,the detail design scheme of the controller and relevant parameter configuration method are given.A semi physical simulation system was established,and the dynamic simulations of the rig under standby condition and working condition were performed.The hardware equipment and software method are debugged and verified by the simulation tests.

  1. 频域和时域船舶动力定位参数辨识算法比较%Comparison of frequency domain and time domain method used in ship dynamic positioning system parameter identification

    Institute of Scientific and Technical Information of China (English)

    谭芳; 宋亚男; 徐荣华; 胡凤娟

    2013-01-01

    针对频域方法和时域方法均被用于船舶动力定位系统建模,但未见特点和适用性对比研究的问题,以船舶动力定位系统参数辨识为对象,进行了频域法R-MISO (reverse multiple input-single output)和时域算法EKF (extended kalmanfilter)的算法实现难易程度、收敛速度、参数依赖性、抗噪能力和适应场合等的比较;基于MATLAB仿真结果显示RMISO算法辨识时间短,不需要设置初始值,适用于在线辨识,而EKF算法去噪能力比较强,需要数据量大,结果依赖初始值,适用于离线辨识,从而为实际船舶动力定位系统参数辨识提供一定的指导.%The methods of frequency domain and time domain are used in the ship dynamic positioning system model,in order to find the comparison of characteristics and applicability,the methods of frequency domain method R-MISO (reverse multiple input-single output) as well as the time domain identification method EKF (extended kalman filter) are taken into consideration in ship dynamic positioning system parameters identification,and carry out a comparative study of difficulty degree,convergence speed,parameter dependence,noise immunity ability and adapt to the comparison of the occasion of the methods.By the MATLAB simulation,the two algorithms are compared,the results show that the R-MISO algorithm is faster,and it doesn't need to provide the initial value,it can be better applied to the online identification,on the other hand the EKF method processes a stronger denoising ability,however it needs a larger number of data as well as the dependence of the initial value,it can be better applied to the offiine identification,to some degree a guidance is provided for the identification process of the ship dynamic positioning system.

  2. A thrust allocation method for dynamic positioning system based on the null space of configuration matrix%基于构造矩阵零空间的动力定位系统推力分配方法

    Institute of Scientific and Technical Information of China (English)

    王莹; 谌栋梁; 谢颖; 张园

    2013-01-01

    在动力定位系统中,推力分配方法是联系运动控制算法和执行机构的纽带,具有十分重要的意义.回顾目前用于海洋工程船舶动力定位系统的主要推力分配算法,针对动力定位系统中常见的过驱动推力分配问题提出了一种基于船舶推进器构造矩阵零空间的分配算法.该方法将构造矩阵分解为基空间和零空间,目标推力可以由基空间保证;零空间向量并不影响总的目标推力,但影响单台推进器的推力,目标函数可以在零空间上优化.并将这一算法应用于某一工程船的动力定位仿真模拟,对该算法进行了验证.%In a dynamic positioning system,the thrust allocation is of great significance to the link between the motion control method and the propulsion system.A survey of thrust allocation methods used in the dynamic positioning (DP) system for marine vessels is presented,and a new thruster allocation method based on the null space thruster configuration matrix of marine vessels is derived for the normal overactuated control allocation problem.The configuration matrix is decomposed to basis space and null space,the target thrust can be guaranteed by the basis space,and the null space doesn' t affect the total thrust but influence the thrust of every single thruster,so the performance function can be optimized on the null space.The method is finally verified by demonstrating it in the dynamic positioning simulation of an engineeing vessel.

  3. Atomic positional disorder, phonon spectrum, and molecular-dynamics simulation of Tl2CaBa2Cu2O8 and Tl2Ca2Ba2Cu3O10

    Science.gov (United States)

    Chaplot, S. L.

    1992-03-01

    The nature of the atomic positional disorder in the high-temperature superconducting ceramic oxides Tl2CaBa2Cu2O8 (Tl 2:1:2:2) and Tl2Ca2Ba2Cu3O10 (Tl 2:2:2:3) is studied with the help of an ionic-type interatomic potential and molecular-dynamics computer simulations. The pair distribution function and the phonon spectrum are calculated using this model and compared with results of neutron-scattering experiments on Tl 2:1:2:2. Calculated results on the partial pair distribution function, partial phonon density of states, mean square atomic vibrational amplitudes, and lattice specific heat are also presented.

  4. 应用车辆-道岔-桥梁耦合动力学分析道岔-桥梁合理相对位置%Vehicle-turnout-bridge Coupling Dynamics Analysis for Turnout-bridge Relative Position

    Institute of Scientific and Technical Information of China (English)

    伍曾; 刘学毅; 王平

    2011-01-01

    为确定道岔、桥梁的合理相对位置,深入研究快速及高速行车条件下车辆-道岔-桥梁的动态相互作用,将车辆、道岔区轨道和桥梁作为一个整体,建立车辆-道岔-桥梁耦合系统动力分析模型,用数值模拟的方法计算分析高速行车条件下道岔区轨道、车辆与连续桥梁结构的动力特性及行车安全性和舒适性.以车速350 km/h通过18号国产道岔,岔桥相对位置为尖轨尖端分别位于桥跨1/4、跨中、3/4跨及墩上,通过计算出的尖轨和心 轨开口量、尖轨和心轨动应力、车体振动加速度、减载率、脱轨系数、舒适性、桥梁振幅、振动加速度和梁端转角等动力响应,确定在车辆-道岔-桥梁耦合动力条件下4×32 m连续梁桥的合理岔桥相对位置.计算结果表明,18号国产道岔铺设于4×32 m连续梁桥上时,道岔尖轨尖端位于1/4跨时综合动力效果较佳.%Dynamical vehicle-turnout-bridge interaction was studied to determine the rational relative position of the turnout and bridge. The dynamic model of the vehicle-turnout-bridge coupling system was established, and the numerical simulation method was applied to analyze the dynamic characteristics of the vehicle-turnout-continuous bridge structure and the safety and comfort of trains running at high speeds. Assume that the train runs at the speed of 350 km/h through China-made Turnout No. 18 and the toe of switch rail was placed at the 1/4 span,mid-span,3/4 span and the top of the pier respectively. The turnout-bridge relative position for the 4×32 m continuous bridge under the action of dynamic coupling of the vehicle-turnout-bridge structure was determined by calculating the train running safety, ride comfort, vibration acceleration of vehicle body, dynamic stresses and displacements of switch rail and nose rail,load reducing rate,derailment coefficient, vibration amplitude and acceleration of bridge, and so on. The calculation results show that

  5. Positive Periodic Solutions of Competition and Corporation Dynamical Model of Two Enterprises%两企业竞争与合作的离散动力学模型的周期解

    Institute of Scientific and Technical Information of China (English)

    徐昌进

    2012-01-01

    The dynamical behavior of a discrete competition and corporation dynamical model of two enterprises χ,(k+l)=χ1(k)exP(r1(ki)-a1(k)χ,(k)-b1(k)(χ2i(k)-c2(k))2},χ:2(k+l)=χ2(k)exp{r2(k)-a2(K)χ2(k)+b2(k)× Cχ1(k)— ci(k))2} ,k∈Z is investigated. By suing the coincidence degree and the related continuation theorem and prior estimates, we obtain an easily verifiable sufficient condition for the existence of positive periodic solutions.%研究一个两企业竞争与合作的离散动力学模型:x1 (k+1)=x1(k)exp{r1(k)-a1(k)x1(k)-b1(k)×(x2(k)-c2(k))2},x2(k+1)=x2(k)exp{r2(k)-a2(k)x2(k)+b2(k)(x1(k)-c1(k))2},k∈Z的动力学行为.运用重合度及相关的延拓定理和先验估计,得到系统存在正周期解的易于检验的充分条件.

  6. Weather optimal control of dynamic positioning system based on nonlinear separation principal%基于非线性分离式原理的动力定位环境最优控制

    Institute of Scientific and Technical Information of China (English)

    瞿洋; 徐海祥; 余文曌

    2016-01-01

    As it' s difficult to measure the sway force and yaw moment under the unknown environmental forces, a new circle center control law for dynamic positioning system was pro-posed to solve the problem of weather optimal heading and po-sition keeping simultaneously. In addition, a PID controller for the cascaded passive-observer-controller system was de-signed based on the nonlinear separation principal, and the stability of cascaded system was guaranteed. Simulation re-sults demonstrate the validity of the proposed circle center control law.%针对在未知环境力作用下船舶横向和艏向所受到的力和力矩具有不便测量的特性,提出一种新的圆心运动控制律,解决了如何获取船舶环境最优艏向和同时保持期望位置的问题.此外,针对无源滤波和控制的级联系统,利用非线性分离式原理设计了PID控制器,保证了该级联系统的稳定性.数值仿真验证了所提出的圆心运动控制律的有效性.

  7. 组织动态测压法在小儿连续臂丛阻滞定位中的应用%Application of Tissue Dynamic Manometry in Positioning Continuous Brachial Plexus Block of Children

    Institute of Scientific and Technical Information of China (English)

    欧阳爱平; 李以平; 黄桂明; 钟宝林

    2014-01-01

    目的:测定腋鞘内、外组织压力的基本范围,评估以穿刺进针过程中组织弹性变化作为主要定位判断依据的可行性。方法:80例拟行上肢手术患儿,男50例,女30例,9~12岁,ASA Ⅰ~Ⅱ级。随机均分为对照组和试验组,男女比例相同,行腋路臂丛阻滞,对照组采用传统定位方法,试验组采用边进针边测压的方法,评估两种定位方法的麻醉效果,观察血管、神经的损伤及局麻药中毒发生情况。结果:试验组腋鞘内组织、腋鞘外肌肉组织和皮下组织的静态压力差异均无统计学意义(P ﹥0.05);腋鞘内组织、腋鞘外肌肉组织和皮下组织5 s、10 s 的动态压力两两之间差异均有统计学意义(P ﹤0.05)。组织动态压力上升范围与以此为指导的臂丛阻滞的麻醉效果相关性良好,且以其指导的连续臂丛阻滞血管、神经的损伤发生率更低。结论:组织动态压力测定较传统定位方法更适用于小儿连续臂丛阻滞的定位。%Objective:To determine the basic range of the exterior and interior tissue pressure of axillary sheath. To evalu-ate the feasibility that tissue elasticity changes were taken as a positioning criterion in the process of puncture. Methods:Eighty ASA Ⅰand Ⅱ patients scheduled for upper limb surgery,including 50 males and 30 females,aged 9 ~ 12 years, were randomly divided into two groups:the control group in which the traditional positioning method was applied and the experimental group in which tissue dynamic manometry was applied in the process of puncture. The sex ratio was the same. The anesthesia effects of patients were evaluated in the two groups and the happenings including blood vessel and nerve injury,the toxicity of local anesthesia were observed. Results:The static pressure difference of subcutaneous tissue and axillary sheath exterior and interior tissue had no statistical significance. But their dynamic

  8. Dynamic positioning: principles, features and operations

    OpenAIRE

    Villar Arenal, José Manuel

    2014-01-01

    Este Trabajo Fin de Grado tiene por objetivo dar una visión general del sistema de Posicionamiento Dinámico, dando una idea de su evolución a lo largo de la historia hasta nuestros días y su importancia en el mundo naval, dando también una introducción al sistema, a sus principios de operación, modelos y aplicaciones, y realizando una explicación de todos los elementos que lo forman, haciendo especial énfasis en los diversos sensores y sistemas de referencia de posición (GPS, DGPS, sistemas h...

  9. Positionality at the Center

    Directory of Open Access Journals (Sweden)

    Catherine Vanner

    2015-11-01

    Full Text Available As a Western feminist supporting and researching gender equality in education in postcolonial contexts, I often wonder: Am I doing more harm than good? The privilege of my social location means that my efforts to support education in postcolonial contexts risk being patronizing, insulting, threatening, imperialist, and recolonizing. Yet neglecting and ignoring postcolonial contexts similarly reflects and reproduces a privileged position. I provide a tentative framework designed to address positionality, power, and privilege while creating an ethical research process for working in a postcolonial context. Beginning with an identification of positionality, the objectives of research, and guiding theoretical frameworks to situate the research in relation to the participants and context, I proceed to establish a methodology designed to minimize the negative effects of power and maximize participants’ empowerment. I position myself as a bricoleur, layering feminist standpoint theory and postcolonial theory, and propose the collaborative data collection and analysis techniques, with particular attention to ethical and cultural sensitivity, using a social constructivist approach to grounded theory. This article highlights the need for Western researchers to reflect upon the power dynamics of their research in postcolonial contexts and develop a strategy for conducting empowering research that prevents the misrepresentation and exploitation of participants. Observations from my doctoral thesis data collection provide examples of how these concepts were operationalized in practice as well as reflections on the disconnect between theorizing and conducting ethical research in postcolonial contexts.

  10. Robot Position Sensor Fault Tolerance

    Science.gov (United States)

    Aldridge, Hal A.

    1997-01-01

    Robot systems in critical applications, such as those in space and nuclear environments, must be able to operate during component failure to complete important tasks. One failure mode that has received little attention is the failure of joint position sensors. Current fault tolerant designs require the addition of directly redundant position sensors which can affect joint design. A new method is proposed that utilizes analytical redundancy to allow for continued operation during joint position sensor failure. Joint torque sensors are used with a virtual passive torque controller to make the robot joint stable without position feedback and improve position tracking performance in the presence of unknown link dynamics and end-effector loading. Two Cartesian accelerometer based methods are proposed to determine the position of the joint. The joint specific position determination method utilizes two triaxial accelerometers attached to the link driven by the joint with the failed position sensor. The joint specific method is not computationally complex and the position error is bounded. The system wide position determination method utilizes accelerometers distributed on different robot links and the end-effector to determine the position of sets of multiple joints. The system wide method requires fewer accelerometers than the joint specific method to make all joint position sensors fault tolerant but is more computationally complex and has lower convergence properties. Experiments were conducted on a laboratory manipulator. Both position determination methods were shown to track the actual position satisfactorily. A controller using the position determination methods and the virtual passive torque controller was able to servo the joints to a desired position during position sensor failure.

  11. Uninterruptible Power Supply Design in Dynamic Positioning Control System with Three Class Notation%DP-3级动力定位控制系统的不间断电源设计

    Institute of Scientific and Technical Information of China (English)

    李伟杰; 洪键; 何凡; 李玉涛; 许亮亮; 杨冰昀

    2015-01-01

    不间断电源(uninterruptible power supply)是能为负载提供不间断电源和清洁电源的供电系统.根据船级社规范的要求,不间断电源对于动力定位系统是必不可少的.现以一艘实际深水钻井船为例,从动力定位系统(dynamic positioning system)的DP3级的角度阐述DP控制系统的不间断电源设计.本文首先介绍了常用的两种不间断电源的类型,再从动力定位系统的角度阐述了不间断电源的负载分配,最后再具体说明了不间断电源在设备布置时需要考虑的要点.

  12. Research and application of a thrust allocation in ship dynamic positioning system%一种船舶推力分配策略的研究与实现

    Institute of Scientific and Technical Information of China (English)

    班勃; 罗岩; 叶宝玉; 王钦若

    2015-01-01

    Thrust allocation , also known as power distribu-tion, is used to distribute the order force or moment of con-troller to each propeller , as one of the key technologies in the ship dynamic positioning system ( DSP ) .It is a puzzling and can not be ignored matter to actualize a high efficient thrust allocation strategy with a fast tracking speed in order to achie-ving ship’s fast dynamic positioning.The proposal calculating angle and thrusting based on pseudo-inverse algorithm were a-dopted to solve angle distribution and amplitude distribution of that propeller , which has an adjustable angle with a constraint direction, namely fast optimization for multi-parameter with constrained.Experimental results show that the force attenua-tion between two adjacent propellers could be avoided effec-tively, the disadvantages in multi-singular-value, repeated it-erations, and slow convergence speed of the other algorithms were improved and a thrust allocation with a rapid calculation , stability and high efficiency was implemented .In view of the simplicity and reliability of this algorithm , it is easy to imple-ment on ship and more suitable for the ship with high-speed positioning .%实现船舶快速动力定位,快速高效的推力分配是一个不可忽视的技术难题。一种船舶推力分配策略的研究与实现主要针对可调节的带方向角约束的多推进器推进角度计算问题和各推进器推力幅值分配问题,即带约束的多参数快速最优解的求解问题。以先分配推进器推进角为原则,再采用伪逆算法分配推进器推力,实现推进器能耗最小。实验结果表明,该分配策略可以有效避免相邻近的推进器之间推力衰减,解决其他算法中的多奇异值问题和多次迭代计算问题,并克服其收敛时间长的缺点,实现推力分配计算的快速性、稳定性、高效性。该算法简单可靠,易于在船舶上实现,因此更适用于船舶的高速定位。

  13. Discrete dynamics versus analytic dynamics

    DEFF Research Database (Denmark)

    Toxværd, Søren

    2014-01-01

    For discrete classical Molecular dynamics obtained by the “Verlet” algorithm (VA) with the time increment h there exists a shadow Hamiltonian H˜ with energy E˜(h) , for which the discrete particle positions lie on the analytic trajectories for H˜ . Here, we proof that there, independent...

  14. Dynamic capabilities

    DEFF Research Database (Denmark)

    Grünbaum, Niels Nolsøe; Stenger, Marianne

    2013-01-01

    it was dominated by a lack of systematism, assessment, monitoring, marketing speculations and feasibility calculation. Furthermore, the sphere was dictated by asymmetric supplier-customer relationships and negotiation power leading, among other possible factors, to meager profitability.......The consequences of dynamic capabilities (i.e. innovation performance and profitability) is an under researched area in the growing body of literature on dynamic capabilities and innovation management. This study aims to examine the relationship between dynamic capabilities, innovation performance...... and profitability of small and medium sized manufacturing enterprises operating in volatile environments. A multi-case study design was adopted as research strategy. The findings reveal a positive relationship between dynamic capabilities and innovation performance in the case companies, as we would expect. It was...

  15. 5th International Symposium on Positive Systems

    CERN Document Server

    Farina, Lorenzo; Setola, Roberto; Germani, Alfredo

    2017-01-01

    This book presents high-quality original contributions on positive systems, including topics such as: monotone dynamical systems in mathematical biology and game theory; mathematical developments for networked systems in biology, chemistry and the social sciences; linear and nonlinear positive operators; dynamical analysis, observation and control of positive distributed parameter systems; stochastic realization theory; biological systems with positive variables and positive controls; iterated function systems; nonnegative dynamic processes; and dimensioning problems for collaborative systems. The book comprises a selection of the best papers presented at the POSTA 2016, the 5th International Symposium on Positive Systems, which was held in Rome, Italy, in September 2016. This conference series represents a targeted response to the growing need for research that reports on and critically discusses a wide range of topics concerning the theory and applications of positive systems.

  16. 基于模型预测控制的动力定位过驱动控制设计%Over-actuated controller design for dynamic positioning system based on model predictive control

    Institute of Scientific and Technical Information of China (English)

    梁海志; 李芦钰; 欧进萍

    2014-01-01

    The dynamic positioning system ( DPS) of the deepwater semi-submersible platform can only control low-frequency motions of surge, sway and yaw. DPS can be considered as an over-actuated system, because the number of propellers is more than the horizontal plane degrees of freedom. Model predictive control ( MPC) which integrates the virtual control force calculation and thrust allocation was adopted. The control forces were explicitly expressed by the propellers'thrust forces, which fully considered the propellers′physical performance, and the thrust change rate was considered as the control parameters. In the design, the environment disturbance was predicted firstly based on the current dynamic states, achieving the initial distribution of environmental perturbations by using the least squares method. And then the standard model predictive control was done, which takes full consideration of the thrust loss due to thrust-thrust interaction problems. It effectively avoided thrust loss by setting the thrust angle between the upstream and downstream thrusters. Based on these designs, while the virtual control forces are gotten, they are allocated directly. Finally the effectiveness of the algorithm is verified.%半潜式平台动力定位系统仅能控制纵荡、横荡和艏摇的低频运动,而整个系统安装的推力器个数大于被控自由度个数,因此整个定位系统为过驱动系统。针对该系统,采用模型预测控制,将虚拟控制力计算和推力分配实现一体化设计。控制力由推力器推力显式表达,充分考虑了推力器物理性能,以推力器推力变化率为控制参数。设计中,首先利用当前运动状态预测环境扰动,通过最小二乘法实现环境扰动的初次分配,然后再进行标准模型预测控制,充分考虑了桨-桨干扰造成的推力损失问题,通过设置上下游推力器间推力夹角,有效地避免了推力损失。最后给出数值算例验证了该方法。

  17. Optimal Thrust Allocation Based on Fuel-efficiency for Dynamic Positioning System%基于能耗最优化的动力定位推力分配逻辑算法研究

    Institute of Scientific and Technical Information of China (English)

    杨世知; 王磊; 张申

    2011-01-01

    文章为动力定位系统执行器的设计提供了两种推力分配最优化的求解方法,旨在寻求一种理想的推力器输出,包括推力与方位角,以维持动力定位系统能力.通过求解非线性约束最优化问题,得出时效性、稳定性与可控制性强的推力分配模块.文中采用一个或若干个合适的结构矩阵来描述推力器的位置及其性能,采用不同的边界条件对系统要求进行描述,如降低推力损失等.基于一个简单的算例,分别采用遗传算法和序列二次方法进行求解,改变约束条件并分析程序运行结果,对比信号输出及其能耗情况,论证两种算法的可行性与稳定性.文中还对比了五种不同的情况,包括约束条件以及算法的变化,以满足不同的应用需求.%The two several methods of thrust distribution in a propulsion system of Dynamic Positioning System (DPS) are presented in this paper. With detail simulation and analysis, this paper concentrates on finding out an optimal thrust allocation (TA), which could gain desired forces and moments acting on the vehicle so as to keep position. Special attention is paid to solve the non-linear constrained thrust allocation problems. And the proposed methods are to set up a configuration matrix which exactly describe the layout of thrusters of the DP propulsion system. An illustrative example based on Genetic Algorithm (GA) and Sequential Quadratic Programming (SQP) is provided to demonstrate the effectiveness and correctness of the proposed methods. Five algorithms suited for different control conditions are presented.

  18. Analysis and Comparison of Two Filtering Methods for Ship Dynamic Positioning System%两种船舶动力定位系统滤波方法的分析与比较

    Institute of Scientific and Technical Information of China (English)

    郭娟; 邹早建; 王晓飞

    2013-01-01

      Offshore platforms and many offshore operating ships are equipped with Dynamic Position-ing systems in ocean engineering. It is of great importance to investigate the performance of ship DP system and its control issues. In this paper, two different filtering and state estimation techniques of Kalman filter and nonlinear passive observer are introduced to separate the Low Frequency (LF) mo-tion from the ship motion measurements contaminated by the first-order wave-induced High Fre-quency (HF) motion. These two methods are applied to two DP control systems based on the linear and nonlinear models of ship kinematics and dynamics, respectively. PID control algorithm is used in both models for its simplicity and efficiency in application. Finally, to test the designed controllers and filtering methods and to validate the advantage of the nonlinear passive observer control model, simulation on a model of supply vessel for DP and tracking control is conducted and the perfor-mances of both control systems are analyzed and compared.%  海洋平台和很多海上工作船舶都装备了动力定位系统。开展船舶动力定位系统及其控制效果的研究在海洋工程领域具有重要的意义。文章分别采用两种滤波和状态估计方法,即卡尔曼滤波器和非线性被动观测器,对一阶波浪力干扰的高频船舶运动测量信号进行滤波并得到低频船舶运动信号。这两种方法分别用于基于运动学和动力学理论建立的船舶运动线性模型和非线性模型;控制算法采用的是实际应用中简单有效的PID控制器。通过在一艘专门用于动态定位和航迹跟踪研究的补给船模型上进行计算机仿真和对结果进行比较分析,验证了所设计的两套控制模型的控制效果并证实了基于非线性被动观测器的非线性模型优于基于卡尔曼滤波器的线性模型。

  19. Forest dynamics.

    Science.gov (United States)

    Frelich, Lee

    2016-01-01

    Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics

  20. Benign positional vertigo

    Science.gov (United States)

    Vertigo - positional; Benign paroxysmal positional vertigo; BPPV: dizziness- positional ... Benign positional vertigo is also called benign paroxysmal positional vertigo (BPPV). It is caused by a problem in the inner ear. ...

  1. Positive maps, positive polynomials and entanglement witnesses

    CERN Document Server

    Skowronek, Lukasz

    2009-01-01

    We link the study of positive quantum maps, block positive operators, and entanglement witnesses with problems related to multivariate polynomials. For instance, we show how indecomposable block positive operators relate to biquadratic forms that are not sums of squares. Although the general problem of describing the set of positive maps remains open, in some particular cases we solve the corresponding polynomial inequalities and obtain explicit conditions for positivity.

  2. Positive maps, positive polynomials and entanglement witnesses

    Energy Technology Data Exchange (ETDEWEB)

    Skowronek, Lukasz; Zyczkowski, Karol [Institute of Physics, Jagiellonian University, Krakow (Poland)], E-mail: lukasz.skowronek@uj.edu.pl, E-mail: karol@tatry.if.uj.edu.pl

    2009-08-14

    We link the study of positive quantum maps, block positive operators and entanglement witnesses with problems related to multivariate polynomials. For instance, we show how indecomposable block positive operators relate to biquadratic forms that are not sums of squares. Although the general problem of describing the set of positive maps remains open, in some particular cases we solve the corresponding polynomial inequalities and obtain explicit conditions for positivity.

  3. Navicular bone position determined by positional MRI

    DEFF Research Database (Denmark)

    Hansen, Philip; Johannsen, Finn E; Hangaard, Stine

    2016-01-01

    OBJECTIVE: To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). MATERIALS AND METHODS: Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G......: Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors....

  4. Dynamic capabilities

    DEFF Research Database (Denmark)

    Grünbaum, Niels Nolsøe; Stenger, Marianne

    2013-01-01

    and profitability of small and medium sized manufacturing enterprises operating in volatile environments. A multi-case study design was adopted as research strategy. The findings reveal a positive relationship between dynamic capabilities and innovation performance in the case companies, as we would expect. It was...... it was dominated by a lack of systematism, assessment, monitoring, marketing speculations and feasibility calculation. Furthermore, the sphere was dictated by asymmetric supplier-customer relationships and negotiation power leading, among other possible factors, to meager profitability....

  5. In-vivo three-dimensional carpal bone kinematics during flexion-extension and radio-ulnar deviation of the wrist: Dynamic motion versus step-wise static wrist positions.

    Science.gov (United States)

    Foumani, M; Strackee, S D; Jonges, R; Blankevoort, L; Zwinderman, A H; Carelsen, B; Streekstra, G J

    2009-12-11

    An in-vivo approach to the measurement of three-dimensional motion patterns of carpal bones in the wrist may have future diagnostic applications, particularly for ligament injuries of the wrist. Static methods to measure carpal kinematics in-vivo only provide an approximation of the true kinematics of the carpal bones. This study is aimed at finding the difference between dynamically and statically acquired carpal kinematics. For eight healthy subjects, static and a dynamic measurements of the carpal kinematics were performed for a flexion-extension and a radio-ulnar deviation movement. Dynamic scans were acquired by using a four-dimensional X-ray imaging system during an imposed cyclic motion. To assess static kinematics of the wrists, three-dimensional rotational X-ray scans were acquired during step-wise flexion-extension and radio-ulnar deviation. The helical axis rotations and the rotation components. i.e. flexion-extension, radio-ulnar deviation and pro-supination were the primary parameters. Linear mixed model statistical analysis was used to determine the significance of the difference between the dynamically and statically acquired rotations of the carpal bones. Small and in most cases negligible differences were observed between the dynamic motion and the step-wise static motion of the carpal bones. The conclusion is that in the case of individuals without any pathology of the wrist, carpal kinematics can be studied either dynamically or statically. Further research is required to investigate the dynamic in-vivo carpal kinematics in patients with dynamic wrist problems.

  6. for hybrid dynamical systems

    Directory of Open Access Journals (Sweden)

    Wassim M. Haddad

    2001-01-01

    Full Text Available In this paper we develop a unified dynamical systems framework for a general class of systems possessing left-continuous flows; that is, left-continuous dynamical systems. These systems are shown to generalize virtually all existing notions of dynamical systems and include hybrid, impulsive, and switching dynamical systems as special cases. Furthermore, we generalize dissipativity, passivity, and nonexpansivity theory to left-continuous dynamical systems. Specifically, the classical concepts of system storage functions and supply rates are extended to left-continuous dynamical systems providing a generalized hybrid system energy interpretation in terms of stored energy, dissipated energy over the continuous-time dynamics, and dissipated energy over the resetting events. Finally, the generalized dissipativity notions are used to develop general stability criteria for feedback interconnections of left-continuous dynamical systems. These results generalize the positivity and small gain theorems to the case of left-continuous, hybrid, and impulsive dynamical systems.

  7. De-Escalation Strategies in Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Early Breast Cancer (BC): Final Analysis of the West German Study Group Adjuvant Dynamic Marker-Adjusted Personalized Therapy Trial Optimizing Risk Assessment and Therapy Response Prediction in Early BC HER2- and Hormone Receptor-Positive Phase II Randomized Trial-Efficacy, Safety, and Predictive Markers for 12 Weeks of Neoadjuvant Trastuzumab Emtansine With or Without Endocrine Therapy (ET) Versus Trastuzumab Plus ET.

    Science.gov (United States)

    Harbeck, Nadia; Gluz, Oleg; Christgen, Matthias; Kates, Ronald Ernest; Braun, Michael; Küemmel, Sherko; Schumacher, Claudia; Potenberg, Jochem; Kraemer, Stefan; Kleine-Tebbe, Anke; Augustin, Doris; Aktas, Bahriye; Forstbauer, Helmut; Tio, Joke; von Schumann, Raquel; Liedtke, Cornelia; Grischke, Eva-Maria; Schumacher, Johannes; Wuerstlein, Rachel; Kreipe, Hans Heinrich; Nitz, Ulrike Anneliese

    2017-09-10

    Purpose Human epidermal growth factor receptor 2 (HER2)-positive/hormone receptor (HR)-positive breast cancer is a distinct subgroup associated with lower chemotherapy sensitivity and slightly better outcome than HER2-positive/HR-negative disease. Little is known about the efficacy of the combination of endocrine therapy (ET) with trastuzumab or with the potent antibody-cytotoxic, anti-HER2 compound trastuzumab emtansine (T-DM1) with or without ET for this subgroup. The West German Study Group trial, ADAPT (Adjuvant Dynamic Marker-Adjusted Personalized Therapy Trial Optimizing Risk Assessment and Therapy Response Prediction in Early Breast Cancer) compares pathologic complete response (pCR) rates of T-DM1 versus trastuzumab with ET in early HER2-positive/HR-positive breast cancer. Patients and Methods In this prospective, neoadjuvant, phase II trial, 375 patients with early breast cancer with HER2-positive and HR-positive status (n = 463 screened) were randomly assigned to 12 weeks of T-DM1 with or without ET or to trastuzumab with ET. The primary end point was pCR (ypT0/is/ypN0). Early response was assessed in 3-week post-therapeutic core biopsies (proliferation decrease ≥ 30% Ki-67 or cellularity response). Secondary end points included safety and predictive impact of early response on pCR. Adjuvant therapy followed national standards. Results Baseline characteristics were well balanced among the arms. More than 90% of patients completed the therapy per protocol. pCR was observed in 41.0% of patients treated with T-DM1, 41.5% of patients treated with T-DM1 and ET, and 15.1% with trastuzumab and ET ( P < .001). Early responders (67% of patients with assessable response) achieved pCR in 35.7% compared with 19.8% in nonresponders (odds ratio, 2.2; 95% CI, 1.24 to 4.19). T-DM1 was associated with a significantly higher prevalence of grade 1 to 2 toxicities, especially thrombocytopenia, nausea, and elevation of liver enzymes. Overall toxicity was low; seventeen

  8. Positive clinical neuroscience: explorations in positive neurology.

    Science.gov (United States)

    Kapur, Narinder; Cole, Jonathan; Manly, Tom; Viskontas, Indre; Ninteman, Aafke; Hasher, Lynn; Pascual-Leone, Alvaro

    2013-08-01

    Disorders of the brain and its sensory organs have traditionally been associated with deficits in movement, perception, cognition, emotion, and behavior. It is increasingly evident, however, that positive phenomena may also occur in such conditions, with implications for the individual, science, medicine, and for society. This article provides a selective review of such positive phenomena--enhanced function after brain lesions, better-than-normal performance in people with sensory loss, creativity associated with neurological disease, and enhanced performance associated with aging. We propose that, akin to the well-established field of positive psychology and the emerging field of positive clinical psychology, the nascent fields of positive neurology and positive neuropsychology offer new avenues to understand brain-behavior relationships, with both theoretical and therapeutic implications.

  9. Position and velocity estimation through acceleration measurements

    OpenAIRE

    Estrada, Antonio; Efimov, Denis; Perruquetti, Wilfrid

    2014-01-01

    International audience; This paper proposes a solution to the problem of velocity and position estimation for a class of oscillating systems whose position, velocity and acceleration are zero mean signals. The proposed scheme considers that the dynamic model of the system is unknown and only noisy acceleration measurements are available.

  10. Positive Psychology: Positive Emotions and Emotional Intelegence

    OpenAIRE

    2008-01-01

    The paper focuses on the and emotional intelligence. We try to answer on some questions regarding the role which positive emotions have in our life’s. The broaden-and-build theory (Fredrickson, 1998; 2001) predicts that positive emotions are useful in several ways. They guide present behavior, by broadening one’s attention and cognition, setting the stage for creative, explorative, and innovative pursuits. As well, positive emotions build personal and social resources to help individuals achi...

  11. Near periodicity in dynamical systems

    Institute of Scientific and Technical Information of China (English)

    陈文成

    1995-01-01

    The notion of near periodicity is shown to be equivalent to that of weak near periodicity in dynamical systems. A sufficient condition for the positive near periodicity of a point in dynamical systems is given. The structure of nearly periodic dynamical systems is discussed, and a condition is proved to be necessary and sufficient for a dynamical system on a local compact space to be positively nearly periodic.

  12. Dynamic Analysis of a Pendulum Dynamic Automatic Balancer

    Directory of Open Access Journals (Sweden)

    Jin-Seung Sohn

    2007-01-01

    Full Text Available The automatic dynamic balancer is a device to reduce the vibration from unbalanced mass of rotors. Instead of considering prevailing ball automatic dynamic balancer, pendulum automatic dynamic balancer is analyzed. For the analysis of dynamic stability and behavior, the nonlinear equations of motion for a system are derived with respect to polar coordinates by the Lagrange's equations. The perturbation method is applied to investigate the dynamic behavior of the system around the equilibrium position. Based on the linearized equations, the dynamic stability of the system around the equilibrium positions is investigated by the eigenvalue analysis.

  13. Benign positional vertigo - aftercare

    Science.gov (United States)

    Vertigo - positional - aftercare; Benign paroxysmal positional vertigo - aftercare; BPPV - aftercare; Dizziness - positional vertigo ... Your health care provider may have treated your vertigo with the Epley maneuver . These are head movements ...

  14. Want Positive Behavior? Use Positive Language

    Science.gov (United States)

    Wood, Chip; Freeman-Loftis, Babs

    2012-01-01

    Positive adult language is the professional use of words and tone of voice to enable students to learn in an engaged, active way. This includes learning social skills. To guide children toward choosing and maintaining positive behaviors, adults need to carefully choose the words and tone of voice used when speaking to them. Learning to use…

  15. Positive Education: Positive Psychology and Classroom Interventions

    Science.gov (United States)

    Seligman, Martin E. P.; Ernst, Randal M.; Gillham, Jane; Reivich, Karen; Linkins, Mark

    2009-01-01

    Positive education is defined as education for both traditional skills and for happiness. The high prevalence worldwide of depression among young people, the small rise in life satisfaction, and the synergy between learning and positive emotion all argue that the skills for happiness should be taught in school. There is substantial evidence from…

  16. Completely positive maps with memory

    CERN Document Server

    Daffer, S; Cresser, J D; McIver, J K; Daffer, Sonja; Wodkiewicz, Krzysztof; Cresser, James D.; Iver, John K. Mc

    2003-01-01

    The prevailing description for dissipative quantum dynamics is given by the Lindblad form of a Markovian master equation, used under the assumption that memory effects are negligible. However, in certain physical situations, the master equation is essentially of a non-Markovian nature. This paper examines master equations that possess a memory kernel, leading to a replacement of white noise by colored noise. The conditions under which this leads to a completely positive, trace-preserving map are discussed for an exponential memory kernel. A physical model that possesses such an exponential memory kernel is presented. This model contains a classical, fluctuating environment based on random telegraph signal stochastic variables.

  17. Children distinguish between positive pride and hubris.

    Science.gov (United States)

    Nelson, Nicole L; Russell, James A

    2015-11-01

    Adults distinguish expressions of hubris from those of positive pride. To determine whether children (N = 183; 78-198 months old) make a similar distinction, we asked them to attribute emotion labels and a variety of social characteristics to dynamic expressions intended to convey hubris and positive pride. Like adults, children attributed different emotion labels to the expressions, and this tendency increased with age. Girls were more likely to distinguish between the expressions than boys were. Children also associated more positive social characteristics with the expression of positive pride and more negative characteristics with the expression of hubris.

  18. Chiral heterotic strings with positive cosmological constant

    Science.gov (United States)

    Florakis, Ioannis; Rizos, John

    2016-12-01

    We present explicit examples of semi-realistic heterotic models with spontaneously broken supersymmetry, which dynamically lead to breaking scales much smaller than MPlanck and exponentially small positive values for the cosmological constant. Contrary to field theoretic intuition, we find that the global structure of the effective potential is significantly affected by contributions of massive and non-level matched string states and we investigate the conditions that dynamically ensure a number of desired properties.

  19. Chiral Heterotic Strings with Positive Cosmological Constant

    CERN Document Server

    Florakis, Ioannis

    2016-01-01

    We present explicit examples of semi-realistic heterotic models with spontaneously broken supersymmetry, which dynamically lead to breaking scales much smaller than $M_{\\rm Planck}$ and exponentially small positive values for the cosmological constant. Contrary to field theoretic intuition, we find that the global structure of the effective potential is significantly affected by contributions of massive and non-level matched string states and we investigate the conditions that dynamically ensure a number of desired properties.

  20. Multi-technology positioning

    CERN Document Server

    Lohan, Elena-Simona; Wymeersch, Henk; Seco-Granados, Gonzalo; Nykänen, Ossi

    2017-01-01

    This book provides an overview of positioning technologies, applications and services in a format accessible to a wide variety of readers. Readers who have always wanted to understand how satellite-based positioning, wireless network positioning, inertial navigation, and their combinations work will find great value in this book. Readers will also learn about the advantages and disadvantages of different positioning methods, their limitations and challenges. Cognitive positioning, adding the brain to determine which technologies to use at device runtime, is introduced as well. Coverage also includes the use of position information for Location Based Services (LBS), as well as context-aware positioning services, designed for better user experience. • Brings understanding of positioning technology to readers from a variety of disciplines • Reviews multiple techniques, providing insight on the pros, cons and challenges related to each • Designed to be a tutorial on basic principles, avoiding unnecessary de...

  1. Positive Deviance: Learning from Positive Anomalies

    Science.gov (United States)

    LeMahieu, Paul G.; Nordstrum, Lee E.; Gale, Dick

    2017-01-01

    Purpose: This paper is one of seven in this volume, each elaborating different approaches to quality improvement in education. The purpose of this paper is to delineate a methodology called positive deviance. Design/methodology/approach: The paper presents the origins, theoretical foundations, core principles and a case study demonstrating an…

  2. Perception of eye positions

    NARCIS (Netherlands)

    Lorteije, J.A.M.; Wezel, R.J.A. van; Lankheet, M.J.M.

    2002-01-01

    In a two-alternative forced-choice psychophysical test human subjects were tested for their ability to perceive their own viewing direction. A small red flash was presented at different horizontal positions left or right from the subjects' eye position on the screen. Eye positions were recorded with

  3. A Study of Vicon System Positioning Performance

    Directory of Open Access Journals (Sweden)

    Pierre Merriaux

    2017-07-01

    Full Text Available Motion capture setups are used in numerous fields. Studies based on motion capture data can be found in biomechanical, sport or animal science. Clinical science studies include gait analysis as well as balance, posture and motor control. Robotic applications encompass object tracking. Today’s life applications includes entertainment or augmented reality. Still, few studies investigate the positioning performance of motion capture setups. In this paper, we study the positioning performance of one player in the optoelectronic motion capture based on markers: Vicon system. Our protocol includes evaluations of static and dynamic performances. Mean error as well as positioning variabilities are studied with calibrated ground truth setups that are not based on other motion capture modalities. We introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments contrary to state-of-the art works that rely on inter-marker distances. The system performs well on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. Our dynamic experiments were carried out at speeds found in real applications. Our work suggests that the system error is less than 2 mm. We also found that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for our dynamic study.

  4. A Study of Vicon System Positioning Performance.

    Science.gov (United States)

    Merriaux, Pierre; Dupuis, Yohan; Boutteau, Rémi; Vasseur, Pascal; Savatier, Xavier

    2017-07-07

    Motion capture setups are used in numerous fields. Studies based on motion capture data can be found in biomechanical, sport or animal science. Clinical science studies include gait analysis as well as balance, posture and motor control. Robotic applications encompass object tracking. Today's life applications includes entertainment or augmented reality. Still, few studies investigate the positioning performance of motion capture setups. In this paper, we study the positioning performance of one player in the optoelectronic motion capture based on markers: Vicon system. Our protocol includes evaluations of static and dynamic performances. Mean error as well as positioning variabilities are studied with calibrated ground truth setups that are not based on other motion capture modalities. We introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments contrary to state-of-the art works that rely on inter-marker distances. The system performs well on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. Our dynamic experiments were carried out at speeds found in real applications. Our work suggests that the system error is less than 2 mm. We also found that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for our dynamic study.

  5. Correlation among Static or Dynamic Position Sense, Function of Lower Extremity and Balance in Patients with Knee Osteoarthri-tis%膝骨关节炎患者下肢动静态位置觉与功能状况和平衡的相关性分析

    Institute of Scientific and Technical Information of China (English)

    郭燕梅; 瓮长水; 陈蔚; 焦伟国

    2013-01-01

    Objective To study the relationship among static and dynamic position sense of lower extremity, physical function, and stat-ic and dynamic balance in patients with knee osteoarthritis. Methods 32 patients with knee osteoarthritis were tested with Lequesne Index, static and dynamic position sense of lower extremity, and fall risk of static and dynamic balance, and analyzed with Pearson correlation coef-ficient. Results The medium-to-high-frequency in postural sway correlated with Lequesne Index (r=0.36, P0.05). The reposition accuracy error of the un-affected/mild-affected lower extremity and affected/severe-affected lower extremity correlated with Lequesne Index (r=0.33~0.39, P0.05);健侧或较轻侧和患侧或较重患侧复位误差平均值与Lequesne患者指数总分(r=0.33~0.39, P<0.05)、动态平衡跌倒风险指数(r=0.65~0.70, P<0.05)、静态平衡跌倒风险指数(r=0.38~0.45, P<0.05)正相关。结论膝骨关节炎患者下肢功能水平的下降会对维持机体平衡的本体感觉传入能力产生不良影响,从而导致其平衡能力的下降。

  6. Pretty Easy Pervasive Positioning

    DEFF Research Database (Denmark)

    Hansen, Rene; Wind, Rico; Jensen, Christian Søndergaard;

    2009-01-01

    With the increasing availability of positioning based on GPS, Wi-Fi, and cellular technologies and the proliferation of mobile devices with GPS, Wi-Fi and cellular connectivity, ubiquitous positioning is becoming a reality. While offerings by companies such as Google, Skyhook, and Spotigo render...... positioning possible in outdoor settings, including urban environments with limited GPS coverage, they remain unable to offer accurate indoor positioning. We will demonstrate a software infrastructure that makes it easy for anybody to build support for accurate Wi-Fi based positioning in buildings. All...... that is needed is a building with Wi-Fi coverage, access to the building, a floor plan of the building, and a Wi-Fi enabled device. Specifically, we will explain the software infrastructure and the steps that must be completed to obtain support for positioning. And we will demonstrate the positioning obtained...

  7. 楼梯间及前室加压送风系统余压动态控制方法%The Dynamic Positive Pressure Control of Pressurization Supply System for Staircase and Antechamber

    Institute of Scientific and Technical Information of China (English)

    王翔; 梁以文

    2011-01-01

    By means of analyzing the imparity of airflow between door opening and closing mode, it is necessary to control the positive pressure of antechambers and smoke-proof staircases (less than 10 floors). Modifying the formula of calculation the dimension of pressure relief damper in the handbook. Using some practical experience from Hong Kong in one project. Present the conclusion that it is effective and economical to use differential pressure detector and by-pass damper to control the positive pressure of an antechambers pressurization supply system, to use pressure relief damper to control the positive pressure of a smoke-proof staircases pressurization supply system.%通过对加压送风系统开关门状态等引起风量差异原因的分析,说明对消防前室加压和10层以下的楼梯间加压系统设置余压控制措施是必要的。提出对目前设计手册中泄压阀选用计算公式的修正。已完成的工程实例参考了香港地区加压系统余压控制的做法。结论是使用压差探测开关+电动旁通阀应用于消防前室加压系统及使用泄压阀应用于10层以下的楼梯间加压系统是有效的,也更经济。

  8. Perceived positions determine crowding.

    Science.gov (United States)

    Maus, Gerrit W; Fischer, Jason; Whitney, David

    2011-01-01

    Crowding is a fundamental bottleneck in object recognition. In crowding, an object in the periphery becomes unrecognizable when surrounded by clutter or distractor objects. Crowding depends on the positions of target and distractors, both their eccentricity and their relative spacing. In all previous studies, position has been expressed in terms of retinal position. However, in a number of situations retinal and perceived positions can be dissociated. Does retinal or perceived position determine the magnitude of crowding? Here observers performed an orientation judgment on a target Gabor patch surrounded by distractors that drifted toward or away from the target, causing an illusory motion-induced position shift. Distractors in identical physical positions led to worse performance when they drifted towards the target (appearing closer) versus away from the target (appearing further). This difference in crowding corresponded to the difference in perceived positions. Further, the perceptual mislocalization was necessary for the change in crowding, and both the mislocalization and crowding scaled with drift speed. The results show that crowding occurs after perceived positions have been assigned by the visual system. Crowding does not operate in a purely retinal coordinate system; perceived positions need to be taken into account.

  9. Perceived positions determine crowding.

    Directory of Open Access Journals (Sweden)

    Gerrit W Maus

    Full Text Available Crowding is a fundamental bottleneck in object recognition. In crowding, an object in the periphery becomes unrecognizable when surrounded by clutter or distractor objects. Crowding depends on the positions of target and distractors, both their eccentricity and their relative spacing. In all previous studies, position has been expressed in terms of retinal position. However, in a number of situations retinal and perceived positions can be dissociated. Does retinal or perceived position determine the magnitude of crowding? Here observers performed an orientation judgment on a target Gabor patch surrounded by distractors that drifted toward or away from the target, causing an illusory motion-induced position shift. Distractors in identical physical positions led to worse performance when they drifted towards the target (appearing closer versus away from the target (appearing further. This difference in crowding corresponded to the difference in perceived positions. Further, the perceptual mislocalization was necessary for the change in crowding, and both the mislocalization and crowding scaled with drift speed. The results show that crowding occurs after perceived positions have been assigned by the visual system. Crowding does not operate in a purely retinal coordinate system; perceived positions need to be taken into account.

  10. Positive criminology in practice.

    Science.gov (United States)

    Ronel, Natti; Segev, Dana

    2014-11-01

    The discourse regarding offender rehabilitation has been criticized by various scholars who have claimed that reducing negative causes and managing risk will not automatically prompt positive human development and elements that are associated with desistance. Positive criminology is an innovative concept that challenges the common preoccupation with negative elements, by placing emphasis on human encounters and forces of inclusion that are experienced positively by target individuals and that can promote crime desistance. However, as the concept is relatively new, there are still no guiding principles for the practice of positive criminology that could direct research and the criminal justice system. This article attempts to fill that gap by providing principles that could be practiced by criminal justice personnel and examples of different interventions that reflect positive criminology. The article also provides ideological explanations for adopting the concept of positive criminology in practice.

  11. Logotherapy and positive psychology

    OpenAIRE

    Oscar R. Oro

    2015-01-01

    Psychology omitted to approach, during almost a century, the positive aspects from persons, like creativity, humor, optimism, hope, forgiveness, life meaning, and happiness. These themes are approached by Positive Psychology, with Seligman like the principal exponent. Psychology was dedicated to explore the negative aspects from human beings improving human health. Nevertheless, this pathogenic model could not prevent mental disease. Concepts of Positive Psychology have a solid antecedent in ...

  12. Reflection Positive Doubles

    CERN Document Server

    Jaffe, Arthur

    2016-01-01

    Here we introduce reflection positive doubles, a general framework for reflection positivity, covering a wide variety of systems in statistical physics and quantum field theory. These systems may be bosonic, fermionic, or parafermionic in nature. Within the framework of reflection positive doubles, we give necessary and sufficient conditions for reflection positivity. We use a reflection-invariant cone to implement our construction. Our characterization allows for a direct interpretation in terms of coupling constants, making it easy to check in concrete situations. We illustrate our methods with numerous examples.

  13. The logarithmic beam position monitor

    Science.gov (United States)

    Medvedko, Evgeny A.; Smith, Stephen R.

    2000-11-01

    Modern logarithmic amplifiers offer wide dynamic range, high bandwidth, good logarithmic conformance, and low cost making them attractive for beam position measurements. A log-ratio beam position monitor has been designed and built at SLAC for use at the PEP-II B-Factory. An integrated circuit logarithmic amplifier from Analog Devices, the AD8307, recovers the envelope of the 476 MHz harmonic of the beam signal. A log BPM board with two logarithmic and one differential amplifier performs the basic function of forming an output voltage proportional to the difference of the logarithms of the signal amplitudes on opposite electrodes. This voltage is approximately linear with beam position. For this application, we have limited the video bandwidth of the log amps to 50 kHz in order to remove fill pattern dependence. The log BPM board has an interface for testing and simulating beam offsets. The log BPMs were developed for a PEP-II ring protection chassis. Here the log BPMs function to identify dangerous orbit excursions. These excursions are signaled to a system, which can dump the beam. Two such chassis serve to protect the PEP-II rings.

  14. The dilemmas of victim positioning

    Directory of Open Access Journals (Sweden)

    Dorte Marie Søndergaard

    2015-08-01

    Full Text Available This article centres on some of the dilemmas contained within victim positioning. Such dilemmas are often overlooked by the authorities involved with people subjected to relational aggression. 2 For example, when teachers rule out cases of bullying because the victim has 'participated in' or 'laughed at' some of the bullies' initiatives, or when a rape victim's status as a victim is questioned because, in the lead up to the assault, she was supposedly friendly to the rapist. In these cases, it could be useful to explore the reason for the bullying victim's apparent collusion or to better understand the premises for the rape victim's positioning options in relation to the perpetrator. In other words, it could be fruitful to explore the dynamics and dilemmas of the victim position. In this article, I aim to reflect on the motivational conditions of the victim phenomenon. These reflections are based on an analysis of qualitative data produced through interviews with school children as well as on relevant secondary literature.

  15. An Inexpensive Position Transducer.

    Science.gov (United States)

    Fox, J.; And Others

    1989-01-01

    Described is a position transducer used to convert the position of an object into a voltage read by a computer with use of an interface board. The arrangement of the apparatus, electronic circuit, and typical graph displays are presented. Discussed is the instructional use of the transducer. (YP)

  16. Den positive psykologis metoder

    DEFF Research Database (Denmark)

    Andersen, Frans Ørsted; Mørck, Line Lerche; Nissen, Poul Erik

    En antologi der giver en introduktion til en række af de metoder der anvendes til forskning, assessment, test, udviklingsarbejde og intervention indenfor den positive psykologi.......En antologi der giver en introduktion til en række af de metoder der anvendes til forskning, assessment, test, udviklingsarbejde og intervention indenfor den positive psykologi....

  17. The effect of thruster failure on the optimal operational direction of DP-2 dynamic positioning system%推力器失效形式对DP-2级动力定位系统最优作业方向影响

    Institute of Scientific and Technical Information of China (English)

    刘翰林; 王磊; 闫芳

    2012-01-01

    Taking a semi-submersible platform with a DP-2 dynamic positioning system working in 3000m depth water as an example, a research is taken on the maximum force of external environment, in which a platform can resist at various angles with the same direction of wind wave and current, and then an optimal operational direction is obtained. An analysis is made on the impact of different thruster failure on the dynamic positioning capability. Finally, a general discipline is obtained and can be extended to common platforms.%以3000m水深DP-2级动力定位半潜平台为算例,研究在风浪流同向作用下,平台在各个角度下所能抵抗的最大外界环境力,得到最优作业方向.在此角度下,着重分析当不同推力器失效时,对动力定位能力的影响.得到一般规律,并推广到一般平台.

  18. An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.

    Science.gov (United States)

    Sod, Gary A; Riggs, Laura M; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S

    2010-01-01

    To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=15 pairs). For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Mean yield load, yield stiffness, and failure load under axial compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.

  19. Complex dynamics

    CERN Document Server

    Carleson, Lennart

    1993-01-01

    Complex dynamics is today very much a focus of interest. Though several fine expository articles were available, by P. Blanchard and by M. Yu. Lyubich in particular, until recently there was no single source where students could find the material with proofs. For anyone in our position, gathering and organizing the material required a great deal of work going through preprints and papers and in some cases even finding a proof. We hope that the results of our efforts will be of help to others who plan to learn about complex dynamics and perhaps even lecture. Meanwhile books in the field a. re beginning to appear. The Stony Brook course notes of J. Milnor were particularly welcome and useful. Still we hope that our special emphasis on the analytic side will satisfy a need. This book is a revised and expanded version of notes based on lectures of the first author at UCLA over several \\Vinter Quarters, particularly 1986 and 1990. We owe Chris Bishop a great deal of gratitude for supervising the production of cour...

  20. POSITIONING STRATEGIES DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Shakhshir Ghassan

    2014-07-01

    Full Text Available The positioning strategy has suffered serious changes in the last few decades, being influenced by the rapid development of competition and the growing focus on specific traits belonging to the market, to the consumer or to the product. The purpose of this paper is to present the developments of theoretical positioning strategies and the orientation from more simple, product oriented strategies, to ones more oriented towards the client and with a briefer period of time. The world is moving in a much faster pace than in the past, thanks to communication development so companies are obliged to adopt more specific strategies in order for them to be effective. This essay represents a literary review presenting a documentary research within the scientific articles and strategy and positioning books. The paper begins with the analysis of company strategies and the marketing strategies in general. The first author to group the product positioning strategies is Porter with his three generic strategies. Following the development of brands and because of the lack of competitiveness in the simple generic positioning strategies, this paper has also presented the newer positioning strategies proposed by Kotler, Treacy & Wiersema, and also more complex ones such as Bowman's Strategy Clock and Blankson and Kalafatis positioning strategy based on the type of the consumer. The fast expansion of local brands in all categories has led to mistakes in positioning strategies, categories also presented in the current essay. The results of this study show that new positioning strategies are more and more based on the consumer and market segments and on the product specification - which have also evolved in the last decades. Adaptability to fast changes in the competitive market will represent the future positioning strategies.

  1. Positive psychiatry: its time has come.

    Science.gov (United States)

    Jeste, Dilip V; Palmer, Barton W; Rettew, David C; Boardman, Samantha

    2015-06-01

    Traditionally, psychiatry has been defined and practiced as a branch of medicine focused on the diagnosis and treatment of mental illnesses. Based on growing empirical evidence, we believe that this definition warrants expansion to include the concept of positive psychiatry. In the present article, we provide a critical overview of this emerging field and a select review of relevant scientific literature. Positive psychiatry may be defined as the science and practice of psychiatry that seeks to understand and promote well-being through assessment and interventions involving positive psychosocial characteristics (PPCs) in people who suffer from or are at high risk of developing mental or physical illnesses. It can also benefit nonclinical populations. Positive psychiatry has 4 main components: (1) positive mental health outcomes (eg, well-being), (2) PPCs that comprise psychological traits (resilience, optimism, personal mastery and coping self-efficacy, social engagement, spirituality and religiosity, and wisdom-including compassion) and environmental factors (family dynamics, social support, and other environmental determinants of overall health), (3) biology of positive psychiatry constructs, and (4) positive psychiatry interventions including preventive ones. There are promising empirical data to suggest that positive traits may be improved through psychosocial and biological interventions. As a branch of medicine rooted in biology, psychiatry, especially with the proposed conceptualization of positive psychiatry, is well poised to provide major contributions to the positive mental health movement, thereby impacting the overall health care of the population.

  2. Positional Concerns and Institutions

    DEFF Research Database (Denmark)

    Landes, Xavier

    2013-01-01

    their implications for economics, positional concerns imply important normative dimensions. There have been presumed to be a symptom of envy, reduce people’s happiness, and create problems of social interaction or economic inefficiencies. Individuals are, for instance, prone to pick states of the world that improve...... that invoking envy or subjective well-being is not fully satisfying for regulating positional concerns. More compelling reasons seem, in complement with efficiency, to be related to considerations for equality. In other words, if institutions could have strong reasons to pay attention to and regulate positional...

  3. Position Resolution in DROIDs

    Science.gov (United States)

    Samedov, Victor V.

    2008-04-01

    Since the very beginning, Distributed Read-Out Imaging Devices (DROIDs) were proposed to achieve both good position and energy resolutions. In DROIDs, the absorption of primary particle energy occurs in a long superconductive strip. Quasiparticles produced in the absorber diffuse along the strip and counted by the superconductive tunnel junctions positioned at the two ends of the strip. In this paper the formula for estimation DROID’s position resolution from experimental data was derived. This formula takes into account correlation between fluctuations of signals of DROID’s detectors.

  4. Positional Concerns and Institutions

    DEFF Research Database (Denmark)

    Landes, Xavier

    2013-01-01

    that invoking envy or subjective well-being is not fully satisfying for regulating positional concerns. More compelling reasons seem, in complement with efficiency, to be related to considerations for equality. In other words, if institutions could have strong reasons to pay attention to and regulate positional...... their implications for economics, positional concerns imply important normative dimensions. There have been presumed to be a symptom of envy, reduce people’s happiness, and create problems of social interaction or economic inefficiencies. Individuals are, for instance, prone to pick states of the world that improve...

  5. Dynamics Analysis of the First Two Steps in Different Crouch Starting Position%对不同蹲踞式起跑姿势起跑后前两步的动力学研究

    Institute of Scientific and Technical Information of China (English)

    邱宝峰

    2012-01-01

    依据起跑器挡板两脚到起跑线后沿的距离,设计了五种不同的蹲踞式起跑姿势。并采用文献资料法、实验法、数理统计法、对比研究法,对5种起跑姿势前两步进行动力学研究。通过对原始数据的处理,重点分析了每种姿势脚着地过程中力随时间变化关系和三个区的压力变化情况。认为,在本实验条件下,给实验对象设计的五种蹲踞式起跑姿势中,第二种姿势最适合该运动员。%This thesis designs five kinds of crouching-starts according to the distance between starting block and starting afteredge line.It adopts the methods of literature review,experiment,statistics and comparative analysis and studies five different crounching starting positions.By processing the raw data,it focuses on the change relationship and pressure change in three areas in the process of each foot touching the ground.In this experimental condition,among the five styles of the crouching starts designed for experimental subject,the second posture is most suitable for the athlete.

  6. The dilemmas of victim positioning

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    2015-01-01

    Based on a conceptualization of bullying and relational aggression in groups as an effect of social dynamics rather than individual deficits – this article reflects upon some of the intricate mechanisms and dilemmas involved in victim positioning. Victims of bullying and relational aggression often....... The hopes of (eventual) social belonging may in that sense work paradoxically as a strong agent in the denial of oppression and marginalization. The article is theoretically informed by poststructuralist conceptualizations and grounded in cases of bullying and marginalization (one of them involving rape......). One case is taken from the empirical data produced by the author and a research project on bullying among children (eXbus: Exploring Bullying in School). Two other cases are borrowed from publications of respectively B. Davies from Australia and A. Evaldsson from Shweden. The article opens insights...

  7. Physical accessibility of non-completely positive maps

    CERN Document Server

    Carteret, H; Zyczkowski, K; Carteret, Hilary; Terno, Daniel R.; Zyczkowski, Karol

    2005-01-01

    We study classes of generalized dynamical maps which are not completely positive. We show that some of these maps correspond to actual, physical systems described in the environmental representation by a unitary dynamics of an extended system and the partial trace. The non complete positivity is due to certain prior correlations of the principal system with the environment. These correlation may have classical nature and no entanglement is necessary to generate a non CP dynamics. We discuss its applications to the dynamical decoupling and quantum channels.

  8. Positivity in the presence of initial system-environment correlation

    CERN Document Server

    Modi, Kavan; Aspuru-Guzik, Alán

    2012-01-01

    Dynamical maps can be nonpositive due to the constraints imposed by the initial system-environment correlation. We find the conditions for positivity and complete positivity of such dynamical maps by using the assignment map. Any initial system-environment correlations make the assignment map nonpositive, while the positivity of the dynamical depends on the interplay between the assignment map and the system-environment coupling. We show how this interplay can reveal and/or hide the nonpositivity of the assignment map. We discuss how this is related to many Markovian models.

  9. Stress Management: Positive Thinking

    Science.gov (United States)

    Healthy Lifestyle Stress management Positive thinking helps with stress management and can even improve your health. Practice overcoming negative self-talk ... with optimism is a key part of effective stress management. And effective stress management is associated with ...

  10. Dynamic Logics of Dynamical Systems

    CERN Document Server

    Platzer, André

    2012-01-01

    We survey dynamic logics for specifying and verifying properties of dynamical systems, including hybrid systems, distributed hybrid systems, and stochastic hybrid systems. A dynamic logic is a first-order modal logic with a pair of parametrized modal operators for each dynamical system to express necessary or possible properties of their transition behavior. Due to their full basis of first-order modal logic operators, dynamic logics can express a rich variety of system properties, including safety, controllability, reactivity, liveness, and quantified parametrized properties, even about relations between multiple dynamical systems. In this survey, we focus on some of the representatives of the family of differential dynamic logics, which share the ability to express properties of dynamical systems having continuous dynamics described by various forms of differential equations. We explain the dynamical system models, dynamic logics of dynamical systems, their semantics, their axiomatizations, and proof calcul...

  11. Optimal Centroid Position Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; McClay, W A; Awwal, A S; Ferguson, S W

    2004-07-23

    The alignment of high energy laser beams for potential fusion experiments demand high precision and accuracy by the underlying positioning algorithms. This paper discusses the feasibility of employing online optimal position estimators in the form of model-based processors to achieve the desired results. Here we discuss the modeling, development, implementation and processing of model-based processors applied to both simulated and actual beam line data.

  12. Positive emotions in education

    OpenAIRE

    Pekrun, Reinhard; Götz, Thomas; Titz, Wolfram; Perry, Raymond P.

    2002-01-01

    In this chapter, we focus on the student side of educational settings. More specifically, we give an overview of our research addressing students' academic emotions, that is, their emotions relating to learning, instruction, and achievement in academic settings associate with attending class, studying, and taking tests and exams. In so doing, we address the following problems in turn: (1) How frequently are positive emotions experienced by students at school and university, and which positive...

  13. 7 positions in 2 hours

    Directory of Open Access Journals (Sweden)

    Jessica Ackerman

    2013-07-01

    Full Text Available 7 positions in 2 hours (2013 is a drawing that documents the process of making the short film Role Reversal Rehearsal. It became quickly apparent that the process of making the work was more dynamic and interesting than the finished piece itself. Relationships between the childcare arrangements of the participants and the collective working process brought about the necessity of collaboration for parent artists. Each participant gave their time, energy and creative insight towards filming a series of birthing positions with roles reversed. The male performer became the central figure in an attempt to prompt empathy, humour, and to embody the importance of the male role in childbirth. There were two hours to choreograph, rehearse, and film the sequence. The drawing by Ackerman encapsulates the 'rhizomatic' approach to producing creative work under the constraints of parenthood. The 'arborescent' structure of hierarchy encouraged in industrial filmmaking is subsumed in favour of a horizontal structure. This new structure allows for the creative input, and flow of collaboration between all people involved - including the 3 and 5 year olds, who contributed ideas for camera and soundtrack in situ.

  14. Local positioning system

    Energy Technology Data Exchange (ETDEWEB)

    Kyker, R.

    1995-07-25

    Navigation systems have been vital to transportation ever since man took to the air and sea. Early navigation systems utilized the sextant to navigate by starlight as well as the magnetic needle compass. As electronics and communication technologies improved, inertial navigation systems were developed for use in ships and missile delivery. These systems consisted of electronic compasses, gyro-compasses, accelerometers, and various other sensors. Recently, systems such as LORAN and the Global Positioning System (GPS) have utilized the properties of radio wave propagation to triangulate position. The Local Positioning System (LPS), described in this paper, is an implementation of a limited inertial navigation system designed to be used on a bicycle. LPS displays a cyclist`s current position relative to a starting location. This information is displayed in Cartesian-like coordinates. To accomplish this, LPS relies upon two sensors, an electronic compass sensor and a distance sensor. The compass sensor provides directional information while the distance sensor provides the distance traveled. This information yields a distance vector for each point in time which when summed produces the cyclist`s current position. LPS is microprocessor controlled and is designed for a range of less than 90 miles.

  15. Nucleosome Positioning and Epigenetics

    Science.gov (United States)

    Schwab, David; Bruinsma, Robijn

    2008-03-01

    The role of chromatin structure in gene regulation has recently taken center stage in the field of epigenetics, phenomena that change the phenotype without changing the DNA sequence. Recent work has also shown that nucleosomes, a complex of DNA wrapped around a histone octamer, experience a sequence dependent energy landscape due to the variation in DNA bend stiffness with sequence composition. In this talk, we consider the role nucleosome positioning might play in the formation of heterochromatin, a compact form of DNA generically responsible for gene silencing. In particular, we discuss how different patterns of nucleosome positions, periodic or random, could either facilitate or suppress heterochromatin stability and formation.

  16. Positioning for Competition.

    Science.gov (United States)

    Lapovsky, Lucie; Hubbell, Loren Loomis

    2000-01-01

    Analyzes results of the 1999 National Association of College and Business Officers tuition discounting survey and identifies trends. Finds colleges and universities are reactively responding to market pressures and proactively trying to analyze and position themselves ahead of the competition, often regional rather than national, for the…

  17. Logotherapy and positive psychology

    Directory of Open Access Journals (Sweden)

    Oscar R. Oro

    2015-09-01

    Full Text Available Psychology omitted to approach, during almost a century, the positive aspects from persons, like creativity, humor, optimism, hope, forgiveness, life meaning, and happiness. These themes are approached by Positive Psychology, with Seligman like the principal exponent. Psychology was dedicated to explore the negative aspects from human beings improving human health. Nevertheless, this pathogenic model could not prevent mental disease. Concepts of Positive Psychology have a solid antecedent in Víktor Frankl ́s studies, which is the Logotherapy founder. This allows incorporating another perspective to approach positive aspects, from a philosophical and anthropological focus. Although the ways adopted by Frank and Seligman are different, both considered main aspects of human existence. Nevertheless, they investigated in different countries (from Europe and EE.UU.; in different circumstances (concentration camps, deaths, tortures; vs. academic context; in different historical periods and different social contexts (a country that lost the war and other that gave freedom to Europeans. In this work is used the concept life sense as the focus in professional formation and psychotherapy approach. 

  18. Positioning Theory in Paradigms

    Institute of Scientific and Technical Information of China (English)

    FU Xiao-qiu

    2015-01-01

    This article discusses the importance of theory and paradigm to a researcher. It starts from introducing and analyzing the definition of the two terms, by using the theories in the field of intercultural communication as examples. To a good researcher, he needs not only clarifying the paradigm his research is positioned, but also integrating the theories in his paradigm.

  19. A Position Paper.

    Science.gov (United States)

    Hixson, Richard A.

    This position paper covers possible problems of collective bargaining. (1) The two sides should not bring prejudgments of good or bad to the negotiating table. (2) Neither side should exaggerate its strength or minimize its weakness. (3) Neither side should confuse intransigence with firmness. (4) The composition of each team must be carefully…

  20. POSITIVE TO THE END

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    After serving at the United Nations (UN) for some 45 years, Secretary General Kofi Annan will leave his position at the end of the year. In a recent written interview with Beijing Review, the world's top diplomat discusses some past and present achievements of the UN, and hopes for the future.

  1. Positive reinforcement for viruses.

    Science.gov (United States)

    Vigant, Frederic; Jung, Michael; Lee, Benhur

    2010-10-29

    Virus-cell membrane fusion requires a critical transition from positive to negative membrane curvature. St. Vincent et al. (2010), in PNAS, designed a class of antivirals that targets this transition. These rigid amphipathic fusion inhibitors are active against an array of enveloped viruses.

  2. Team coordination dynamics.

    Science.gov (United States)

    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.

  3. Evolution of Indoor Positioning Technologies: A Survey

    Directory of Open Access Journals (Sweden)

    Ramon F. Brena

    2017-01-01

    Full Text Available Indoor positioning systems (IPS use sensors and communication technologies to locate objects in indoor environments. IPS are attracting scientific and enterprise interest because there is a big market opportunity for applying these technologies. There are many previous surveys on indoor positioning systems; however, most of them lack a solid classification scheme that would structurally map a wide field such as IPS, or omit several key technologies or have a limited perspective; finally, surveys rapidly become obsolete in an area as dynamic as IPS. The goal of this paper is to provide a technological perspective of indoor positioning systems, comprising a wide range of technologies and approaches. Further, we classify the existing approaches in a structure in order to guide the review and discussion of the different approaches. Finally, we present a comparison of indoor positioning approaches and present the evolution and trends that we foresee.

  4. Studying Dynamics in Business Networks

    DEFF Research Database (Denmark)

    Andersen, Poul Houman; Anderson, Helen; Havila, Virpi;

    1998-01-01

    This paper develops a theory on network dynamics using the concepts of role and position from sociological theory. Moreover, the theory is further tested using case studies from Denmark and Finland...

  5. Positive and Negative Thermal Poling of Germanosilicate Fibres

    DEFF Research Database (Denmark)

    Wong, D.; Wu, W.; Arentoft, Jesper;

    1999-01-01

    In situ measurements of thermal poling of germanosilicate fibers under positive and negative poling voltages show different dynamics of a linear electro-optic effect induced into fibers. The mechanism for the induced electro-optic effect is addressed......In situ measurements of thermal poling of germanosilicate fibers under positive and negative poling voltages show different dynamics of a linear electro-optic effect induced into fibers. The mechanism for the induced electro-optic effect is addressed...

  6. Centralized Cooperative Positioning and Tracking with Realistic Communications Constraints

    DEFF Research Database (Denmark)

    Mensing, Christian; Nielsen, Jimmy Jessen

    2010-01-01

    In this paper, we investigate the performance of centralized cooperative positioning algorithms. Compared to traditional positioning algorithms which solely exploit ranging information from anchor nodes, cooperative positioning additionally uses measurements from peer-to-peer links between...... on the overall performance will be assessed. As we are considering a dynamic scenario, the cooperative positioning algorithms are based on extended Kalman filtering for position estimation and tracking. Simulation results for ultra-wideband based ranging information and WLAN based communications infrastructure...... show the benefits of cooperative position and tracking for realistic measurement and mobility models....

  7. Softness and Amplitudes' Positivity for Spinning Particles

    CERN Document Server

    Bellazzini, Brando

    2016-01-01

    We derive positivity bounds for scattering amplitudes of particles with arbitrary spin using unitarity, analyticity and crossing symmetry. The bounds imply the positivity of certain low-energy coefficients of the effective action that controls the dynamics of the light degrees of freedom. We show that low-energy amplitudes strictly softer than $O(p^4)$ do not admit unitary ultraviolet completions unless the theory is free. This enforces a bound on the energy growth of scattering amplitudes in the region of validity of the effective theory. We discuss explicit examples including the Goldstino from spontaneous supersymmetry breaking, and the theory of a spin-1/2 fermion with a shift symmetry.

  8. Enlargements of positive sets

    CERN Document Server

    Bot, Radu Ioan

    2008-01-01

    In this paper we introduce the notion of enlargement of a positive set in SSD spaces. To a maximally positive set $A$ we associate a family of enlargements $\\E(A)$ and characterize the smallest and biggest element in this family with respect to the inclusion relation. We also emphasize the existence of a bijection between the subfamily of closed enlargements of $\\E(A)$ and the family of so-called representative functions of $A$. We show that the extremal elements of the latter family are two functions recently introduced and studied by Stephen Simons. In this way we extend to SSD spaces some former results given for monotone and maximally monotone sets in Banach spaces.

  9. Benign paroxysmal positional vertigo

    Directory of Open Access Journals (Sweden)

    Guo Xiang-Dong

    2011-01-01

    Full Text Available Benign paroxysmal positional vertigo (BPPV is a common clinical disorder characterized by brief recurrent spells of vertigo often brought about by certain head position changes as may occur with looking up, turning over in bed, or straightening up after bending over. It is important to understand BPPV not only because it may avert expensive and often unnecessary testing, but also because treatment is rapid, easy, and effective in >90% of cases. The diagnosis of BPPV can be made based on the history and examination. Patients usually report episodes of spinning evoked by certain movements, such as lying back or getting out of bed, turning in bed, looking up, or straightening after bending over. At present, the generally accepted recurrence rate of BPPV after successful treatment is 40%-50% at 5 years of average follow-up. There does appear to be a subset of individuals prone to multiple recurrences.

  10. Positional Right Ventricular Obstruction in Pectus Excavatum.

    Science.gov (United States)

    Underwood, Katherine; Vorsanger, Matthew; Saric, Muhamed; Skolnick, Adam H

    2017-01-25

    Pectus excavatum is one of the most common congenital chest wall deformities. The degree of sternal depression, which may result in compression of the right heart by the chest wall, is variable. While typically asymptomatic, there are various symptoms that can result from severe pectus excavatum. We report on a patient with severe pectus excavatum leading to dynamic obstruction of the right ventricular outflow tract in the seated position.

  11. Mapping your competitive position.

    Science.gov (United States)

    D'Aveni, Richard A

    2007-11-01

    A price-benefit positioning map helps you see, through your customers' eyes, how your product compares with all its competitors in a market. You can draw such a map quickly and objectively, without having to resort to costly, time-consuming consumer surveys or subjective estimates of the excellence of your product and the shortcomings of all the others. Creating a positioning map involves three steps: First, define your market to include everything your customers might consider to be your product's competitors or substitutes. Second, track the price your customers actually pay (wholesale or retail? bundled or unbundled?) and identify what your customers see as your offering's primary benefit. This is done through regression analysis, determining which of the product's attributes (as described objectively by rating services, government agencies, R&D departments, and the like) explains most of the variance in its price. Third, draw the map by plotting on a graph the position of every product in the market you've selected according to its price and its level of primary benefit, and draw a line that runs through the middle of the points. What you get is a picture of the competitive landscape of your market, where all the products above the line command a price premium owing to some secondary benefit customers value, and all those below the line are positioned to earn market share through lower prices and reduced secondary benefits. Using examples as varied as Harley-Davidson motorcycles, Motorola cell phones, and the New York restaurant market, Tuck professor D'Aveni demonstrates some of the many ways the maps can be used: to locate unoccupied or less-crowded spaces in highly competitive markets, for instance, or to identify opportunities created through changes in the relationship between the primary benefit and prices. The maps even allow companies to anticipate--and counter-- rivals' strategies. R eprint RO711G

  12. Review of HRP Positions

    Energy Technology Data Exchange (ETDEWEB)

    Center for Reliability Studies

    2007-01-01

    The Department of Energy (DOE) Human Reliability Program (HRP), published as 10 CFR Part 712, is currently being reviewed and revised to address concerns identified during its implementation. Although these ''page changes'' primarily incorporate clarification of terms and language, the following discussion relates to broadening the definition of positions that require HRP certification that is found in {section}712.10.

  13. Thought Positions in Sculpture

    OpenAIRE

    2015-01-01

    Thought Positions in Sculpture presents ten contemporary artists who have encountered the archive through the stories of their own art practice. The physical exhibition at Huddersfield Art Gallery refers to existing works of art from Leeds Museums and Galleries Sculpture Collection, archival material from the Henry Moore Institute, digitised archival material from the Tate Gallery, audio material from the British Library and other archival sites, some of which are inventions by the artist the...

  14. Matching Through Position Auctions

    OpenAIRE

    Terence Johnson

    2009-01-01

    This paper studies how an intermediary should design two-sided matching markets when agents are privately informed about their quality as a partner and can make payments to the intermediary. Using a mechanism design approach, I derive sufficient conditions for assortative matching to be profit- or welfare-maximizing, and then show how to implement the optimal match and payments through two-sided position auctions. This sharpens our understanding of intermediated matching markets by clarifying...

  15. Positional information, in bits.

    Science.gov (United States)

    Dubuis, Julien O; Tkacik, Gasper; Wieschaus, Eric F; Gregor, Thomas; Bialek, William

    2013-10-08

    Cells in a developing embryo have no direct way of "measuring" their physical position. Through a variety of processes, however, the expression levels of multiple genes come to be correlated with position, and these expression levels thus form a code for "positional information." We show how to measure this information, in bits, using the gap genes in the Drosophila embryo as an example. Individual genes carry nearly two bits of information, twice as much as would be expected if the expression patterns consisted only of on/off domains separated by sharp boundaries. Taken together, four gap genes carry enough information to define a cell's location with an error bar of ~1 along the anterior/posterior axis of the embryo. This precision is nearly enough for each cell to have a unique identity, which is the maximum information the system can use, and is nearly constant along the length of the embryo. We argue that this constancy is a signature of optimality in the transmission of information from primary morphogen inputs to the output of the gap gene network.

  16. Quantum Positioning System

    CERN Document Server

    Bahder, T B

    2004-01-01

    A quantum positioning system (QPS) is proposed that can provide a user with all four of his space-time coordinates. The user must carry a corner cube reflector, a good clock, and have a two-way classical channel of communication with the origin of the reference frame. Four pairs of entangled photons (biphotons) are sent through four interferometers: three interferometers are used to determine the user's spatial position, and an additional interferometer is used to synchronize the user's clock to coordinate time in the reference frame. The spatial positioning part of the QPS is similar to a classical time-of-arrival (TOA) system, however, a classical TOA system (such as GPS) must have synchronized clocks that keep coordinate time and therefore the clocks must have long-term stability, whereas in the QPS only a photon coincidence counter is needed and the clocks need only have short-term stability. Several scenarios are considered for a QPS: one is a terrestrial system and another is a space-based-system compos...

  17. Dynamic Camera Positioning and Reconfiguration for Multi-Camera Networks

    OpenAIRE

    Konda, Krishna Reddy

    2015-01-01

    The large availability of different types of cameras and lenses, together with the reduction in price of video sensors, has contributed to a widespread use of video surveillance systems, which have become a widely adopted tool to enforce security and safety, in detecting and preventing crimes and dangerous events. The possibility for personalization of such systems is generally very high, letting the user customize the sensing infrastructure, and deploying ad-hoc solutions based on the curren...

  18. Discrete dynamical models

    CERN Document Server

    Salinelli, Ernesto

    2014-01-01

    This book provides an introduction to the analysis of discrete dynamical systems. The content is presented by an unitary approach that blends the perspective of mathematical modeling together with the ones of several discipline as Mathematical Analysis, Linear Algebra, Numerical Analysis, Systems Theory and Probability. After a preliminary discussion of several models, the main tools for the study of linear and non-linear scalar dynamical systems are presented, paying particular attention to the stability analysis. Linear difference equations are studied in detail and an elementary introduction of Z and Discrete Fourier Transform is presented. A whole chapter is devoted to the study of bifurcations and chaotic dynamics. One-step vector-valued dynamical systems are the subject of three chapters, where the reader can find the applications to positive systems, Markov chains, networks and search engines. The book is addressed mainly to students in Mathematics, Engineering, Physics, Chemistry, Biology and Economic...

  19. Dynamical Languages

    Science.gov (United States)

    Xie, Huimin

    The following sections are included: * Definition of Dynamical Languages * Distinct Excluded Blocks * Definition and Properties * L and L″ in Chomsky Hierarchy * A Natural Equivalence Relation * Symbolic Flows * Symbolic Flows and Dynamical Languages * Subshifts of Finite Type * Sofic Systems * Graphs and Dynamical Languages * Graphs and Shannon-Graphs * Transitive Languages * Topological Entropy

  20. An All-Time-Domain Moving Object Data Model, Location Updating Strategy, and Position Estimation

    National Research Council Canada - National Science Library

    Wu, Qunyong; Huang, Junyi; Luo, Jianping; Yang, Jianjun

    2015-01-01

    .... Secondly, we proposed a new dynamic threshold location updating strategy. The location updating threshold was given dynamically in accordance with the velocity, accuracy, and azimuth positioning information from the GPS...

  1. Position from gravity

    Science.gov (United States)

    Mather, R. S.

    1973-01-01

    Procedures for obtaining position from surface gravity observations are reviewed and their relevance assessed in the context of the application of modern geodetic techniques to programs of Earth and ocean physics. Solutions based on the use of surface layer techniques, the discrete value approach, and the development from Green's theorem are stated in summary, the latter being extended to order e cubed in the height anomaly. The representation of the surface gravity field which is required in order that this accuracy may be achieved is discussed. Interim techniques which could be used in the absence of such a representation are also outlined.

  2. QRA techniques on dynamic positioning systems during drilling operations in the Arctic: With emphasis on the dynamic positioning operator

    OpenAIRE

    2015-01-01

    With the Norwegian government moving the ice edge farther north than ever before, opening for new areas for petroleum exploration, it will need research on how these areas can affect oil and gas operations. A sensitive environment along with the harsh Arctic climate and remote distances means that severe accidents, like blowouts, will have serious impacts and make cleanup and rescue actions to challenging operations. Additionally, humans working under these conditions are prone to be affected...

  3. MOF positioning technology and device fabrication.

    Science.gov (United States)

    Falcaro, Paolo; Ricco, Raffaele; Doherty, Cara M; Liang, Kang; Hill, Anita J; Styles, Mark J

    2014-08-21

    Metal organic frameworks (MOFs) offer the highest surface areas per gram of any known material. As such, they epitomise resource productivity in uses where specific surface area is critical, such as adsorption, storage, filtration and catalysis. However, the ability to control the position of MOFs is also crucial for their use in devices for applications such as sensing, delivery, sequestration, molecular transport, electronics, energy production, optics, bioreactors and catalysis. In this review we present the current technologies that enable the precise positioning of MOFs onto different platforms. Methods for permanent localisation, dynamic localisation, and spatial control of functional materials within MOF crystals are described. Finally, examples of devices in which the control of MOF position and functionalisation will play a major technological role are presented.

  4. Metallic positive expulsion diaphragms

    Science.gov (United States)

    Gleich, D.

    1972-01-01

    High-cycle life ring-reinforced hemispherical type positive expulsion diaphragm performance was demonstrated by room temperature fluid expulsion tests of 13" diameter, 8 mil thick stainless steel configurations. A maximum of eleven (11) leak-free, fluid expulsions were achieved by a 25 deg cone angle diaphragm hoop-reinforced with .110-inch cross-sectional diameter wires. This represents a 70% improvement in diaphragm reversal cycle life compared to results previously obtained. The reversal tests confirmed analytic predictions for diaphragm cycle life increases due to increasing values of diaphragm cone angle, radius to thickness ratio and material strain to necking capacity. Practical fabrication techniques were demonstrated for forming close-tolerance, thin corrugated shells and for obtaining closely controlled reinforcing ring stiffness required to maximize diaphragm cycle life. A non-destructive inspection technique for monitoring large local shell bending strains was developed.

  5. Algorithms for Global Positioning

    DEFF Research Database (Denmark)

    Borre, Kai; Strang, Gilbert

    The emergence of satellite technology has changed the lives of millions of people. In particular, GPS has brought an unprecedented level of accuracy to the field of geodesy. This text is a guide to the algorithms and mathematical principles that account for the success of GPS technology and repla......The emergence of satellite technology has changed the lives of millions of people. In particular, GPS has brought an unprecedented level of accuracy to the field of geodesy. This text is a guide to the algorithms and mathematical principles that account for the success of GPS technology....... At the heart of the matter are the positioning algorithms on which GPS technology relies, the discussion of which will affirm the mathematical contents of the previous chapters. Numerous ready-to-use MATLAB codes are included for the reader. This comprehensive guide will be invaluable for engineers...

  6. Inductive Position Sensor

    Science.gov (United States)

    Youngquist, Robert C. (Inventor); Simmons, Stephen M. (Inventor)

    2015-01-01

    An inductive position sensor uses three parallel inductors, each of which has an axial core that is an independent magnetic structure. A first support couples first and second inductors and separate them by a fixed distance. A second support coupled to a third inductor disposed between the first and second inductors. The first support and second support are configured for relative movement as distance changes from the third inductor to each of the first and second inductors. An oscillating current is supplied to the first and second inductors. A device measures a phase component of a source voltage generating the oscillating current and a phase component of voltage induced in the third inductor when the oscillating current is supplied to the first and second inductors such that the phase component of the voltage induced overlaps the phase component of the source voltage.

  7. Position paper on mesotherapy

    Directory of Open Access Journals (Sweden)

    Rashmi Sarkar

    2011-01-01

    Full Text Available Mesotherapy is a controversial cosmetic procedure which has received publicity among the lay people, in the internet and in the media. It refers to minimally invasive techniques which consist of the use of intra- or subcutaneous injections containing liquid mixture of compounds (pharmaceutical and homeopathic medications, plant extracts, vitamins and other ingredients to treat local medical and cosmetic conditions. This position paper has examined the available evidence and finds that acceptable scientific evidence for its effectiveness and safety is lacking. IADVL taskforce, therefore would like to state that the use of this technique remains controversial at present. Further research and well-designed controlled scientific studies are required to substantiate the claims of benefit of this mode of therapy.

  8. Galileo positioning technology

    CERN Document Server

    Lohan, Elena; Sand, Stephan; Hurskainen, Heikki

    2015-01-01

    This book covers multi-band Galileo receivers (especially E1-E5 bands of Galileo) and addresses all receiver building blocks, from the antenna and front end, through details of the baseband receiver processing blocks, up to the navigation processing, including the Galileo message structure and Position, Velocity, Time (PVT) computation. Moreover, hybridization solutions with communications systems for improved localization are discussed and an open-source GNSS receiver platform (available for download) developed at Tampere University of Technology (TUT) is addressed in detail. • Takes a holistic approach to GALILEO and related systems, such as EGNOS and hybrid solutions on mobile phones; • Provides an invaluable reference to Binary Offset Carrier modulations and related families, which are some of the trademarks of GALILEO; • Includes a detailed survey of GALILEO receiver research in Europe and existing software-defined radio (SDR) GALILEO receiver implementations; • Addresses the multiple challen...

  9. Experimental and CFD analysis of nozzle position of subsonic ejector

    Institute of Scientific and Technical Information of China (English)

    Xilai ZHANG; Shiping JIN; Suyi HUANG; Guoqing TIAN

    2009-01-01

    The influence of nozzle position on the performance of an ejector was analyzed qualitatively with free jet flow model. Experimental investigations and computational fluid dynamics (CFD) analysis of the nozzle position of the subsonic ejector were also conducted. The results show that there is an optimum nozzle position for the ejector. The ejecting coefficient reaches its maximum when the nozzle is positioned at the optimum and decreases when deviating. Moreover, the nozzle position of an ejector is not a fixed value, but is influenced greatly by the flow parameters. Considering the complexity of the ejector, CFD is reckoned as a useful tool in the design of ejectors.

  10. 深水半潜式钻井平台动力定位系统时域仿真模拟与模型试验%Time Domain Simulation and Model Experiment of Dynamic Position System in Deepwater Semi-Submersible Drilling Platform

    Institute of Scientific and Technical Information of China (English)

    杨旭; 孙丽萍; 陈静

    2014-01-01

    针对一个动力定位系统定位的深水半潜式钻井平台,建立了动力定位系统数值模拟模型,运用了PID控制理论、低通滤波器以及推进器分配方程对动力定位系统进行了仿真。同时,在哈尔滨工程大学深水水池中对该半潜式钻井平台进行了动力定位能力模型试验,试验采用1:50缩尺比模型,加载了推力器模拟系统,利用自主研发的界面控制程序与瑞典的位移测量系统研究模型在不同情况下的动力定位能力。对数值模拟与模型试验结果进行分析,给出了平台在完整工况与推进器部分失效状况时的运动响应与动力定位能力,环境载荷考虑了静水情况与不同风浪流载荷情况,将数值模拟计算结果与试验结果进行了对比。试验结果与计算结果均表明该平台定位能力满足要求。数值模型与试验模型切实可行,可用于动力定位系统的初步设计与仿真模拟。1%This paper creates an adaptable numerical model with control theory of PID and equations of low pass filter and thrusters allocation. Model test of the semisubmersible platform with dynamic position system is presented. The model is equipped with thruster simulation system, control program and motion capture system. Both experiment and calculation are used to analyze motion response of the platform with dynamic position system in intact and thruster failure conditions. The results show that the platform satisfies the requirements of rules and both the numerical model and model test are available to the analysis of DPS in time domain.

  11. Relationship of condylar position to disc position and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Incesu, L.; Taskaya-Yilmaz, N. E-mail: nergizy@omu.edu.tr; Oeguetcen-Toller, M.; Uzun, E

    2004-09-01

    Introduction/objective: The purpose of this study was to assess whether condylar position, as depicted by magnetic resonance imaging, was an indicator of disc morphology and position. Methods and material: One hundred and twenty two TMJs of 61 patients with temporomandibular joint disorder were examined. Condylar position, disc deformity and degree of anterior disc displacement were evaluated by using magnetic resonance imaging. Results and discussion: Posterior condyle position was found to be the main feature of temporomandibular joints with slight and moderate anterior disc displacement. No statistical significance was found between the condylar position, and reducing and nonreducing disc positions. On the other hand, superior disc position was found to be statistically significant for centric condylar position. Conclusion: It was concluded that posterior condyle position could indicate anterior disc displacement whereas there was no relation between the position of condyle and the disc deformity.

  12. Molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Ladd, A.J.C.

    1988-08-01

    The basic methodology of equilibrium molecular dynamics is described. Examples from the literature are used to illustrate how molecular dynamics has been used to resolve theoretical controversies, provide data to test theories, and occasionally to discover new phenomena. The emphasis is on the application of molecular dynamics to an understanding of the microscopic physics underlying the transport properties of simple fluids. 98 refs., 4 figs.

  13. Dynamics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Dynamics Lab replicates vibration environments for every Navy platform. Testing performed includes: Flight Clearance, Component Improvement, Qualification, Life...

  14. Dynamical systems

    CERN Document Server

    Sternberg, Shlomo

    2010-01-01

    Celebrated mathematician Shlomo Sternberg, a pioneer in the field of dynamical systems, created this modern one-semester introduction to the subject for his classes at Harvard University. Its wide-ranging treatment covers one-dimensional dynamics, differential equations, random walks, iterated function systems, symbolic dynamics, and Markov chains. Supplementary materials offer a variety of online components, including PowerPoint lecture slides for professors and MATLAB exercises.""Even though there are many dynamical systems books on the market, this book is bound to become a classic. The the

  15. Gathering positive experience

    CERN Multimedia

    2009-01-01

    Last Monday, the new CERN Machine Advisory Committee (CMAC) met for the first time, and we had good news to tell its members. Over the weekend, injection tests for both LHC beams were successfully carried out. In other words, we’ve had beam in the LHC for the first time since September 2008. That’s a good feeling, but it’s no reason for complacency. There’s still a long way to go before first physics at the new energy frontier. As the Bulletin has reported over recent weeks, we’re gathering a lot of positive experience with the new quench detection and protection system (QPS), which is already allowing us to monitor the LHC far better than we were able to in the past. So far, the QPS for three of the LHC’s eight sectors has been put through its paces, and we’ve also power tested those sectors to 2000 amperes, the equivalent of around 1.2 TeV per beam. The next step is to slowly increase the current to 4000 amperes, and...

  16. Exposing Position Uncertainty in Middleware

    DEFF Research Database (Denmark)

    Langdal, Jakob; Kjærgaard, Mikkel Baun; Toftkjær, Thomas;

    2010-01-01

    Traditionally, the goal for positioning middleware is to provide developers with seamless position transparency, i.e., providing a connection between the application domain and the positioning sensors while hiding the complexity of the positioning technologies in use. A key part of the hidden com...

  17. Secure positioning in wireless networks

    DEFF Research Database (Denmark)

    Capkun, Srdjan; Hubaux, Jean-Pierre

    2006-01-01

    So far, the problem of positioning in wireless networks has been studied mainly in a non-adversarial settings. In this work, we analyze the resistance of positioning techniques to position and distance spoofing attacks. We propose a mechanism for secure positioning of wireless devices, that we call...... Verifiable Multilateration. We then show how this mechanism can be used to secure positioning in sensor networks. We analyze our system through simulations....

  18. Molecular dynamics

    NARCIS (Netherlands)

    Bergstra, J.A.; Bethke, I.

    2002-01-01

    Molecular dynamics is a model for the structure and meaning of object based programming systems. In molecular dynamics the memory state of a system is modeled as a fluid consisting of a collection of molecules. Each molecule is a collection of atoms with bindings between them. A computation is model

  19. Dynamic Squares

    NARCIS (Netherlands)

    Blackburn, P.; Venema, Y.

    2008-01-01

    This paper examines various propositional logics in which the dynamic implication connective (discussed in Groenendijk and Stokhof's (1992) Dynamic Predicate Logic and Kamp's (1981) Discourse Representation Theory) plays the central role. Our approach is modal: the basic idea is to view as a binary

  20. Record dynamics

    DEFF Research Database (Denmark)

    Robe, Dominic M.; Boettcher, Stefan; Sibani, Paolo

    2016-01-01

    When quenched rapidly beyond their glass transition, colloidal suspensions fall out of equilibrium. The pace of their dynamics then slows down with the system age, i.e., with the time elapsed after the quench. This breaking of time translational invariance is associated with dynamical observables...

  1. Fluid Dynamics

    DEFF Research Database (Denmark)

    Brorsen, Michael

    These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University.......These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University....

  2. Persuasion dynamics

    Science.gov (United States)

    Weisbuch, Gérard; Deffuant, Guillaume; Amblard, Frédéric

    2005-08-01

    We here discuss a model of continuous opinion dynamics in which agents adjust continuous opinions as a result of random binary encounters whenever their difference in opinion is below a given threshold. We concentrate on the version of the model in the presence of few extremists which might drive the dynamics to generalized extremism. A network version of the dynamics is presented here, and its results are compared to those previously obtained for the full-mixing case. The same dynamical regimes are observed, but in rather different parameter regions. We here show that the combination of meso-scale features resulting from the first interaction steps determines the asymptotic state of the dynamics.

  3. Dynamic Optimization

    Science.gov (United States)

    Laird, Philip

    1992-01-01

    We distinguish static and dynamic optimization of programs: whereas static optimization modifies a program before runtime and is based only on its syntactical structure, dynamic optimization is based on the statistical properties of the input source and examples of program execution. Explanation-based generalization is a commonly used dynamic optimization method, but its effectiveness as a speedup-learning method is limited, in part because it fails to separate the learning process from the program transformation process. This paper describes a dynamic optimization technique called a learn-optimize cycle that first uses a learning element to uncover predictable patterns in the program execution and then uses an optimization algorithm to map these patterns into beneficial transformations. The technique has been used successfully for dynamic optimization of pure Prolog.

  4. HIV-Positive-to-HIV-Positive Liver Transplantation

    OpenAIRE

    Calmy, Alexandra; van Delden, Christian; Giostra, Emiliano; Junet, C; Rubbia Brandt, L; Yerly, S; Chave, J-P; Samer, Caroline Flora; Elkrief, Laure; Vionnet, J; Berney, Thierry

    2016-01-01

    Most countries exclude human immunodeficiency virus (HIV)-positive patients from organ donation because of concerns regarding donor-derived HIV transmission. The Swiss Federal Act on Transplantation has allowed organ transplantation between HIV-positive donors and recipients since 2007. We report the successful liver transplantation from an HIV-positive donor to an HIV-positive recipient. Both donor and recipient had been treated for many years with antiretroviral therapy and harbored multidr...

  5. False Position, Double False Position and Cramer's Rule

    Science.gov (United States)

    Boman, Eugene

    2009-01-01

    We state and prove the methods of False Position (Regula Falsa) and Double False Position (Regula Duorum Falsorum). The history of both is traced from ancient Egypt and China through the work of Fibonacci, ending with a connection between Double False Position and Cramer's Rule.

  6. Videofluoroscopic Investigation of Body Position on Articulatory Positioning

    Science.gov (United States)

    Bae, Youkyung; Perry, Jamie L.; Kuehn, David P.

    2014-01-01

    Purpose: To quantitatively examine the effects of body position on the positioning of the epiglottis, tongue, and velum at rest and during speech. Method: Videofluoroscopic data were obtained from 12 healthy adults in the supine and upright positions at rest and during speech while the participants produced 12 VCV sequences. The effects of body…

  7. Positive Psychology and Positive Education: Old Wine in New Bottles?

    Science.gov (United States)

    Kristjansson, Kristjan

    2012-01-01

    The recently fashionable theories of positive psychology have educational ramifications at virtually every level of engagement, culminating in the model of positive education. In this critical review, I scrutinize positive education as a potential theory in educational psychology. Special attention is given to conceptual controversies and…

  8. Positive Psychology and Positive Education: Old Wine in New Bottles?

    Science.gov (United States)

    Kristjansson, Kristjan

    2012-01-01

    The recently fashionable theories of positive psychology have educational ramifications at virtually every level of engagement, culminating in the model of positive education. In this critical review, I scrutinize positive education as a potential theory in educational psychology. Special attention is given to conceptual controversies and…

  9. Positional nystagmus showing neutral points.

    Science.gov (United States)

    Hiruma, Kiyoshi; Numata, Tsutomu

    2004-01-01

    We encountered patients who had their static direction-changing positional nystagmus canceled at about 20-30 degrees yaw head rotation from the supine position. This nystagmus was also canceled when the head was rotated 180 degrees from this position. We call these head positions neutral points. At the neutral points, the cupula of the horizontal semicircular canal of the affected ear is positioned vertical to the gravitational plane and no deflection of the cupula occurs. The positional nystagmus observed (except the neutral points) was thought to occur due to a "heavy cupula" or "light cupula", which may be determined by the specific gravity of its endolymph.

  10. Impulse position control algorithms for nonlinear systems

    Energy Technology Data Exchange (ETDEWEB)

    Sesekin, A. N., E-mail: sesekin@list.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation); Institute of Mathematics and Mechanics, Ural Division of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation); Nepp, A. N., E-mail: anepp@urfu.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation)

    2015-11-30

    The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

  11. Impulse position control algorithms for nonlinear systems

    Science.gov (United States)

    Sesekin, A. N.; Nepp, A. N.

    2015-11-01

    The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

  12. Fractional-Order Control of Pneumatic Position Servosystems

    Directory of Open Access Journals (Sweden)

    Cao Junyi

    2011-01-01

    Full Text Available A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo system is established. The fractional-order controller for pneumatic position servo and its implementation in industrial computer is designed. The experiments with fractional-order controller are carried out under various conditions, which include sine position signal with different frequency and amplitude, step position signal, and variety inertial load. The results show the effectiveness of the proposed scheme and verify their fine control performance for pneumatic position servo system.

  13. Dynamic triggering

    Science.gov (United States)

    Hill, David P.; Prejean, Stephanie; Schubert, Gerald

    2015-01-01

    Dynamic stresses propagating as seismic waves from large earthquakes trigger a spectrum of responses at global distances. In addition to locally triggered earthquakes in a variety of tectonic environments, dynamic stresses trigger tectonic (nonvolcanic) tremor in the brittle–plastic transition zone along major plate-boundary faults, activity changes in hydrothermal and volcanic systems, and, in hydrologic domains, changes in spring discharge, water well levels, soil liquefaction, and the eruption of mud volcanoes. Surface waves with periods of 15–200 s are the most effective triggering agents; body-wave trigger is less frequent. Triggering dynamic stresses can be < 1 kPa.

  14. Galactic dynamics

    CERN Document Server

    Binney, James

    2008-01-01

    Since it was first published in 1987, Galactic Dynamics has become the most widely used advanced textbook on the structure and dynamics of galaxies and one of the most cited references in astrophysics. Now, in this extensively revised and updated edition, James Binney and Scott Tremaine describe the dramatic recent advances in this subject, making Galactic Dynamics the most authoritative introduction to galactic astrophysics available to advanced undergraduate students, graduate students, and researchers. Every part of the book has been thoroughly overhauled, and many section

  15. Robust Hitting with Dynamics Shaping

    Science.gov (United States)

    Yashima, Masahito; Yamawaki, Tasuku

    The present paper proposes the trajectory planning based on “the dynamics shaping” for a redundant robotic arm to hit a target robustly toward the desired direction, of which the concept is to shape the robot dynamics appropriately by changing its posture in order to achieve the robust motion. The positional error of the end-effector caused by unknown disturbances converges onto near the singular vector corresponding to its maximum singular value of the output controllability matrix of the robotic arm. Therefore, if we can control the direction of the singular vector by applying the dynamics shaping, we will be able to control the direction of the positional error of the end-effector caused by unknown disturbances. We propose a novel trajectory planning based on the dynamics shaping and verify numerically and experimentally that the robotic arm can robustly hit the target toward the desired direction with a simple open-loop control system even though the disturbance is applied.

  16. Benign Paroxysmal Positional Vertigo (BPPV)

    Science.gov (United States)

    ... Rated Nonprofit! Volunteer. Donate. Review. Benign Paroxysmal Positional Vertigo (BPPV) BPPV is the most common vestibular disorder. Benign ... al. Diagnosis and management of benign paroxysmal positional vertigo (BPPV). CMAJ. 2003 169(7):681-693. Nuti D, ...

  17. On some positive definite functions

    OpenAIRE

    Bhatia, Rajendra; Jain, Tanvi

    2014-01-01

    We study the function $(1 - \\|x\\|)\\slash (1 - \\|x\\|^r),$ and its reciprocal, on the Euclidean space $\\mathbb{R}^n,$ with respect to properties like being positive definite, conditionally positive definite, and infinitely divisible.

  18. Spectral Conditions for Positive Maps

    Science.gov (United States)

    Chruściński, Dariusz; Kossakowski, Andrzej

    2009-09-01

    We provide partial classification of positive linear maps in matrix algebras which is based on a family of spectral conditions. This construction generalizes the celebrated Choi example of a map which is positive but not completely positive. It is shown how the spectral conditions enable one to construct linear maps on tensor products of matrix algebras which are positive but only on a convex subset of separable elements. Such maps provide basic tools to study quantum entanglement in multipartite systems.

  19. Dissipative dynamics in particle physics

    CERN Document Server

    Romano, R

    2003-01-01

    The subject of this thesis is the study of dissipative dynamics and their properties in particle physics, dealing with neutral B-mesons, neutron interferometry and neutrino physics. Modified expressions for the relevant phenomenological quantities characterizing these systems are obtained. Moreover, the models presented in this work offer the possibility of direct tests of some basic properties of reduced dynamics (in particular the notion of complete positivity) since they represent concrete systems amenable to actual experiments.

  20. Fuzzy Logic Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Roberto García Sánz

    2008-12-01

    Full Text Available The GPS system is not valid for positioning indoors, thus positioning systems are designed using Wi-Fi technology that allows location of a device inside buildings. The use of fuzzy logic is argued by the failure to find positioning systems based on this technology, which seeks toobserve how their use in this field

  1. Introducing Positive Psychology to SLA

    Science.gov (United States)

    MacIntyre, Peter D.; Mercer, Sarah

    2014-01-01

    Positive psychology is a rapidly expanding subfield in psychology that has important implications for the field of second language acquisition (SLA). This paper introduces positive psychology to the study of language by describing its key tenets. The potential contributions of positive psychology are contextualized with reference to prior work,…

  2. Positive Psychology and Outdoor Education

    Science.gov (United States)

    Berman, Dene S.; Davis-Berman, Jennifer

    2005-01-01

    A relatively new movement in psychology, positive psychology, has many implications for the field of outdoor education. Positive psychology has the goal of fostering excellence through the understanding and enhancement of factors that lead to growth. It embraces the view that growth occurs when positive factors are present, as opposed to the…

  3. Dynamic gamma knife radiosurgery.

    Science.gov (United States)

    Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

    2009-03-21

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C and Perfexion units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the dose

  4. Dynamic gamma knife radiosurgery

    Science.gov (United States)

    Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

    2009-03-01

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C™ and Perfexion™ units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the

  5. Dynamic gamma knife radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Luan Shuang; Swanson, Nathan; Chen Zhe [Department of Computer Science, University of New Mexico, Albuquerque, NM 87131 (United States); Ma Lijun [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94143 (United States)], E-mail: sluan@cs.unm.edu, E-mail: nate@cs.unm.edu, E-mail: zchen@cs.unm.edu, E-mail: lijunma@radonc.ucsf.edu

    2009-03-21

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C(TM) and Perfexion(TM) units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can

  6. Navicular bone position determined by positional MRI: a reproducibility study

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Philip; Nybing, Janus D. [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Johannsen, Finn E.; Stallknecht, Sandra E. [Copenhagen University Hospital Bispebjerg, Institute of Sports Medicine Copenhagen, Copenhagen, NV (Denmark); Hangaard, Stine; Hansen, Bjarke B. [Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark); Boesen, Mikael [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark)

    2016-02-15

    To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scanner). Scanning was performed in supine and standing position, respectively. Two radiologists evaluated the images in a blinded manner. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC) and 95 % limits of agreement as a percentage of the mean (LOA%). Intraobserver and interobserver reliability was ''substantial'' in both supine and standing position (ICC 0.86-0.98) and showed good agreement (LOA% 4.9-14.7 %). Between-day reliability of navicular height and medial navicular position in standing position remained substantial (ICC 0.85-0.92) with adequate agreement (LOA% 8.3-19.8 %). In supine position between-day reliability was ''moderate'' for NVH (ICC 0.72) and ''slight'' for MNP (ICC 0.39). Agreement remained adequate between-days for MNP in supine position (LOA% 17.7 %), but it was less than adequate for NVH in supine position (LOA% 24.2 %). Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors. (orig.)

  7. The Kepler False Positive Table

    Science.gov (United States)

    Bryson, Steve; Kepler False Positive Working Group

    2015-01-01

    The Kepler Space Telescope has detected thousands of candidate exoplanets by observing transit signals in a sample of more than 190,000 stars. Many of these transit signals are false positives, defined as a transit-like signal that is not due to a planet orbiting the target star (or a bound companion if the target is a multiple-star system). Astrophysical causes of false positives include background eclipsing binaries, planetary transits not associated with the target star, and non-planetary eclipses of the target star by stellar companions. The fraction of Kepler planet candidates that are false positives ranges from about 10% at high Galactic latitudes to 40% at low Galactic latitudes. Creating a high-reliability planet candidate catalog for statistical studies such as occurrence rate calculations requires removing clearly identified false positives.The Kepler Object of Interest (KOI) catalog at the NExScI NASA Exoplanet Archive flags false positives, and will soon provide a high-level classification of false positives, but lacks detailed description of why a KOI was determined to be a false positive. The Kepler False Positive Working Group (FPWG) examines each false positive in detail to certify that it is correctly identified as a false positive, and determines the primary reason(s) a KOI is classified as a false positive. The work of the FPWG will be published as the Kepler False Positive Table, hosted at the NExScI NASA Exoplanet Archive.The Kepler False Positive Table provides detailed information on the evidence for background binaries, transits caused by stellar companions, and false alarms. In addition to providing insight into the Kepler false positive population, the false positive table gives information about the background binary population and other areas of astrophysical interest. Because a planet around a star not associated with the target star is considered a false positive, the false positive table likely contains further planet candidates

  8. Autophagy meets FUS-positive Stress Granules

    Science.gov (United States)

    Matus, Soledad; Bosco, Daryl A.; Hetz, Claudio

    2015-01-01

    Mutations in fused in sarcoma/translocated in liposarcoma (FUS/TLS or FUS) are linked to familial cases of amyotrophic lateral sclerosis (ALS). Mutant FUS selectively accumulates into discrete cytosolic structures known as stress granules under various stress conditions. In addition, mutant FUS expression can alter the dynamics and morphology of stress granules. Although the link between mutant-FUS and stress granules is well established, the mechanisms modulating stress granule formation and disassembly in the context of ALS are poorly understood. In this issue of Neurobiology of Aging, Ryu and coworkers uncover the impact of autophagy on the potential toxicity of mutant-FUS positive stress granules. The authors provide evidence indicating that enhanced autophagy activity reduces the number of stress granules, which in the case of cells containing mutant-FUS positive stress granules, is neuroprotective. Overall, this study identifies an intersection between the proteostasis network and alterations in RNA metabolism in ALS through the dynamic assembly and disassembly of stress granules. PMID:25444610

  9. 正电晕放电耦合Ag-TiO2降解乙烯的动力学及参数优化%Dynamic modeling and parameters optimization of degrading ethylene by positive corona coupled with Ag-TiO2

    Institute of Scientific and Technical Information of China (English)

    李利钦; 梁嘉亮; 叶盛英; 陈雪梅; 宋贤良

    2014-01-01

    direct current positive corona-elemental silver deposit nanometer TiO2. In this paper, the cylinder wall was used as corona discharge reactor, with needle-array-versus- inner-cylinder-wall corona electrode, and with nano-TiO2 as catalysis deposited with nanometer silver. The impacts of silver doping amount, discharge power and gas flow rate and other factors on ethylene degradation and ozone control effect were carried out in the simulation of the horticultural products cold storage environment, verified the intrinsic kinetics of the reaction process by surveying the changes of concentration of ethylene as well as ozone. The results showed that ethylene degradation dynamics model of positive corona discharge coupling activated carbon fiber (ACF) supported Ag doped nano-TiO2 (Ag-TiO2/ACF) was established. Corona discharge coupling Ag-TiO2*/ACF catalytic membrane on degradation of ethylene and control of the ozone concentration has a superior performance by comparing the reaction constant of Runge Kutta method for solving differential equations and least square method for dynamics model. By means of quadratic rotary combination experiment and regression fitting, quadratic multinomial model of reaction constant of corona discharge coupling Ag-TiO2*/ACF catalytic membrane on the degradation of ethylene and the limits of predicted values of ozone concentration was established. The validity of the model was verified, and parameters of reaction system were optimized at the same time. The optimal conditions for storage of apple was that silver doping amount of 0.5%, discharge power of 0.47 W and gas flow rate of 400 L/h. The research can provide a reference for the technology of direct current positive corona discharge coupling nano-TiO2 in the application of storage and transportation equipment of horticultural products.

  10. Detecting Positioning Errors and Estimating Correct Positions by Moving Window.

    Science.gov (United States)

    Song, Ha Yoon; Lee, Jun Seok

    2015-01-01

    In recent times, improvements in smart mobile devices have led to new functionalities related to their embedded positioning abilities. Many related applications that use positioning data have been introduced and are widely being used. However, the positioning data acquired by such devices are prone to erroneous values caused by environmental factors. In this research, a detection algorithm is implemented to detect erroneous data over a continuous positioning data set with several options. Our algorithm is based on a moving window for speed values derived by consecutive positioning data. Both the moving average of the speed and standard deviation in a moving window compose a moving significant interval at a given time, which is utilized to detect erroneous positioning data along with other parameters by checking the newly obtained speed value. In order to fulfill the designated operation, we need to examine the physical parameters and also determine the parameters for the moving windows. Along with the detection of erroneous speed data, estimations of correct positioning are presented. The proposed algorithm first estimates the speed, and then the correct positions. In addition, it removes the effect of errors on the moving window statistics in order to maintain accuracy. Experimental verifications based on our algorithm are presented in various ways. We hope that our approach can help other researchers with regard to positioning applications and human mobility research.

  11. Dynamical maps and density matrices

    Energy Technology Data Exchange (ETDEWEB)

    Asorey, M [Departamento de Fisica Teorica. Facultad de Ciencias. Universidad de Zaragoza, 50009 Zaragoza (Spain); Kossakowski, A [Institute of Physics, Nicolaus Copernicus University Torun 87-100 (Poland); Marmo, G [Dipartimento di Scienze Fisiche, Universita Federico II di Napoli and INFN, Sezione di Napoli Complesso University di Monte Sant' Angelo, Via Cintia, 80125 Napoli (Italy); Sudarshan, E C G [Department of Physics. University of Texas at Austin Austin, Texas 78712-1081 (United States)

    2009-11-01

    The relations between dynamical maps and quantum states of bipartite systems are analyzed from the perspective of quantum conditional probability. In particular, we explore new interesting relations between completely positive maps, which correspond to quantum channels, and states of bipartite systems which correspond to correlations between the initial and final states. The new connection emerges in a natural way from the generalisation of the classical concept of conditional probability. We develop applications of these relations which prove to be very useful in both directions, either for the classification of positive maps which are not completely positive, the classification of non-decomposable dynamical maps or for the classification of positive partial transpose and entangled states.

  12. DP systems for offshore vessel positioning in deep water

    OpenAIRE

    2013-01-01

    Current industry practices and the suggestions from the literature are that offshore oil exploration and production activities will move into deeper water further from shore. To achieve that, dynamic positioning systems are indispensible. In the past 5 years, there has been a dramatic increase in the number of offshore installations equipped with DP systems. This thesis is focused on comprehensive characteristics, utilities, risk analysis and future trends regarding positioning systems in...

  13. A New Indoor Positioning System Architecture Using GPS Signals

    Science.gov (United States)

    Xu, Rui; Chen, Wu; Xu, Ying; Ji, Shengyue

    2015-01-01

    The pseudolite system is a good alternative for indoor positioning systems due to its large coverage area and accurate positioning solution. However, for common Global Positioning System (GPS) receivers, the pseudolite system requires some modifications of the user terminals. To solve the problem, this paper proposes a new pseudolite-based indoor positioning system architecture. The main idea is to receive real-world GPS signals, repeat each satellite signal and transmit those using indoor transmitting antennas. The transmitted GPS-like signal can be processed (signal acquisition and tracking, navigation data decoding) by the general receiver and thus no hardware-level modification on the receiver is required. In addition, all Tx can be synchronized with each other since one single clock is used in Rx/Tx. The proposed system is simulated using a software GPS receiver. The simulation results show the indoor positioning system is able to provide high accurate horizontal positioning in both static and dynamic situations. PMID:25938199

  14. A New Indoor Positioning System Architecture Using GPS Signals.

    Science.gov (United States)

    Xu, Rui; Chen, Wu; Xu, Ying; Ji, Shengyue

    2015-04-29

    The pseudolite system is a good alternative for indoor positioning systems due to its large coverage area and accurate positioning solution. However, for common Global Positioning System (GPS) receivers, the pseudolite system requires some modifications of the user terminals. To solve the problem, this paper proposes a new pseudolite-based indoor positioning system architecture. The main idea is to receive real-world GPS signals, repeat each satellite signal and transmit those using indoor transmitting antennas. The transmitted GPS-like signal can be processed (signal acquisition and tracking, navigation data decoding) by the general receiver and thus no hardware-level modification on the receiver is required. In addition, all Tx can be synchronized with each other since one single clock is used in Rx/Tx. The proposed system is simulated using a software GPS receiver. The simulation results show the indoor positioning system is able to provide high accurate horizontal positioning in both static and dynamic situations.

  15. Optimal Set-point Chasing of Position Moored Vessel

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens; Bernt, Leira

    2010-01-01

    Dynamic positioning of surface vessels moored to the seabed via a spread mooring system are referred to as position mooring (PM), the main objective of which is to keep the vessel within a small radius from a given position while preventing mooring line breakage. When environmental loads become...... high, position mooring systems apply thruster forces to protect mooring lines and position accuracy may need be relaxed. This paper suggests an new position chasing algorithm that works entirely online, is optimal according to a criterion and can protect any number of mooring lines simultaneously....... Tensions of all mooring lines are included in a cost function where the criticality for each mooring line determine individual weights. With this strategy, external environment effects are included directly by without needing predefined tabular settings of environmental loads as in earlier approaches...

  16. Positivity of the English language

    CERN Document Server

    Kloumann, Isabel M; Harris, Kameron Decker; Bliss, Catherine A; Dodds, Peter Sheridan

    2011-01-01

    Within the last million years, human language has emerged and evolved as a fundamental instrument of social communication and semiotic representation. People use language in part to convey emotional information, leading to the central and contingent questions: (1) What is the emotional spectrum of natural language? and (2) Are natural languages neutrally, positively, or negatively biased? Previous findings are mixed: suggestive evidence of a positive bias has been found in small samples of English words [1-3], framed as the Pollyanna Hypothesis [3] and Linguistic Positivity Bias [1], while the experimental elicitation of emotional words has instead found a strong negative bias [4]. Here, we report that the human-perceived positivity of over 10,000 of the most frequently used English words exhibits a clear positive bias. More deeply, we characterize and quantify distributions of word positivity for four large and distinct corpora, demonstrating that their form is surprisingly invariant with respect to frequenc...

  17. Jumping Dynamics

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2013-01-01

    We propose an alternative paradigm to the conjectured Miransky scaling potentially underlying the physics describing the transition from the conformally broken to the conformally restored phase when tuning certain parameters such as the number of flavors in gauge theories. According to the new...... paradigm the physical scale and henceforth also the massive spectrum of the theory jump at the lower boundary of the conformal window. In particular we propose that a theory can suddenly jump from a Quantum Chromodynamics type spectrum, at the lower boundary of the conformal window, to a conformal one...... without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking....

  18. Dynamic Bifurcations

    CERN Document Server

    1991-01-01

    Dynamical Bifurcation Theory is concerned with the phenomena that occur in one parameter families of dynamical systems (usually ordinary differential equations), when the parameter is a slowly varying function of time. During the last decade these phenomena were observed and studied by many mathematicians, both pure and applied, from eastern and western countries, using classical and nonstandard analysis. It is the purpose of this book to give an account of these developments. The first paper, by C. Lobry, is an introduction: the reader will find here an explanation of the problems and some easy examples; this paper also explains the role of each of the other paper within the volume and their relationship to one another. CONTENTS: C. Lobry: Dynamic Bifurcations.- T. Erneux, E.L. Reiss, L.J. Holden, M. Georgiou: Slow Passage through Bifurcation and Limit Points. Asymptotic Theory and Applications.- M. Canalis-Durand: Formal Expansion of van der Pol Equation Canard Solutions are Gevrey.- V. Gautheron, E. Isambe...

  19. COMPANIES WITH MARKET POSITIONING BRANDS

    OpenAIRE

    Ruxandra Radoviciu; Filimon Stremtan

    2009-01-01

    Positioning a company on the market by the usage of brands is defined as the act ofdesigning the supply and its image on the market, so as to occupy a distinct place in the minds of theirtarget audience. The role of positioning in developing marketing strategy to differentiate products andservices involves the selection of attributes that are considered important for consumers. In order togain a strong position on the market the companies must perform a market analysis, an internalanalysis an...

  20. Vestibular reflexes and positional manoeuvres

    OpenAIRE

    Bronstein, A

    2003-01-01

    Dizziness and vertigo are some of the more frequently encountered symptoms in neurology clinics. In turn, one of the most common causes of vertigo is benign paroxysmal positional vertigo (BPPV), accounting for a quarter of all patients with dizziness and vertigo. Reviewing the value of the positional manoeuvres available is relevant, particularly in the light of the efficient treatments available for BPPV. In this article I will deal with positional manoeuvres first, and then with how vestibu...

  1. Position Auctions with Consumer Search

    OpenAIRE

    Susan Athey; Glenn Ellison

    2011-01-01

    This paper examines a model in which advertisers bid for "sponsored-link" positions on a search engine. The value advertisers derive from each position is endogenized as coming from sales to a population of consumers who make rational inferences about firm qualities and search optimally. Consumer search strategies, equilibrium bidding, and the welfare benefits of position auctions are analyzed. Implications for reserve prices and a number of other auction design questions are discussed.

  2. Position Command Shaping for Vibration Suppression Considering Target Position Correction

    Science.gov (United States)

    Yamamoto, Masafumi; Ito, Kazuaki; Iwasaki, Makoto; Matsui, Nobuyuki

    This paper presents a command shaping technique based on a minimum jerk control approach considering a target position correction during motion, for the fast and precise positioning in vibratory mechatronic systems. The positioning controller is designed by a 2-degrees-of-freedom control: a feedback compensator is synthesized by H∞ control design to ensure the robust stability, while a feedforward compensator suppresses the vibration in response based on a coprime factorization expression of the plant mechanism. The command shaping, on the other hand, eliminates the corresponding vibration components of the primary and secondary modes in the position command, where the continuity of jerk component in the command can be ensured against the target position correction. The effectiveness of the proposed shaping technique has been verified by experiments using a table drive system on machine stand.

  3. Dynamical systems

    CERN Document Server

    Birkhoff, George D

    1927-01-01

    His research in dynamics constitutes the middle period of Birkhoff's scientific career, that of maturity and greatest power. -Yearbook of the American Philosophical Society The author's great book€¦is well known to all, and the diverse active modern developments in mathematics which have been inspired by this volume bear the most eloquent testimony to its quality and influence. -Zentralblatt MATH In 1927, G. D. Birkhoff wrote a remarkable treatise on the theory of dynamical systems that would inspire many later mathematicians to do great work. To a large extent, Birkhoff was writing about his o

  4. On Improving the Energy Efficiency and Robustness of Position Tracking for Mobile Devices

    OpenAIRE

    2010-01-01

    An important feature of a modern mobile device is that it can position itself and support remote position tracking. To be useful, such position tracking has to be energy-efficient to avoid having a major impact on the battery life of the mobile device. Furthermore, tracking has to robustly deliver position updates when faced with changing conditions such as delays and changing positioning conditions. Previous work has established dynamic tracking systems, such as our EnTracked system, as a so...

  5. STRATEGIC MARKET POSITION OF THE GDANSK AIRPORT

    Directory of Open Access Journals (Sweden)

    Henryk Ćwikliński

    2015-09-01

    Full Text Available Airports are a key link of the air transport infrastructure, which is a part of the whole transportation system. Their potential is determined by a network of airlines relations and affects the long-term, strategic position in the market of aviation services. The most possible scenario of the macro-environment of the Gdansk Airport has a relatively high predictability and generally positive influencing on the potential for development in the next years. Only international and demographic areas can constitute a barrier to achieving the strategic objectives. Gdansk Airport takes permanently the third position on the Polish market. Strategic gap analysis leads to the conclusion that, compared to its main competitors Airport Gdansk has a gap of compliance trends, but in relation to smaller regional airports excess gap. GDN services are located in the square "Star" in the BCG matrix. This airport has prepared an investment program till 2035. The dynamics of the projected increase in the number of passengers and air operations in Gdansk is generally slightly higher than the growth nationwide forecasts. The strategic challenge for next years will be to strengthen the status of the GDN as a Polish aviation gateway to Scandinavia.

  6. Global regulation of robots using only position measurements

    NARCIS (Netherlands)

    Berghuis, Harry; Nijmeijer, Henk

    1993-01-01

    In this note we propose a simple solution to the regulation problem of rigid robots based on the availability of only joint position measurements. The controller consists of two parts: (1) a gravitation compensation, (2) a linear dynamic first-order compensator. The gravitation compensation part can

  7. Positive Semidefinite Integrated Covariance Estimation, Factorizations and Asynchronicity

    DEFF Research Database (Denmark)

    Boudt, Kris; Laurent, Sébastien; Lunde, Asger

    observations as possible. The estimator is guaranteed positive semidefinite. Monte Carlo simulations confirm good finite sample properties. In the application we forecast portfolio Value-at-Risk and sector risk exposures for a portfolio of 52 stocks. We find that forecasts obtained from dynamic models...

  8. Community detection in networks with positive and negative links

    NARCIS (Netherlands)

    Traag, V.A.; Bruggeman, J.

    2009-01-01

    Detecting communities in complex networks accurately is a prime challenge, preceding further analyses of network characteristics and dynamics. Until now, community detection took into account only positively valued links, while many actual networks also feature negative links. We extend an existing

  9. Positive automorphisms for self-induced interval exchange transformations

    CERN Document Server

    Jullian, Yann

    2011-01-01

    We give an algorithm to determine if the dynamical system generated by a positive automorphism of the free group can also be generated by a self-induced interval exchange transformation. The algorithm effectively yields the interval exchange transformation in case of success.

  10. Thermal Actuation for Precision Micro Motion and Positioning

    NARCIS (Netherlands)

    Paalvast, S.L.

    2010-01-01

    The primary goal of this research was to study the feasibility of a thermal micro actuator for improved tracking performance of a Hard Disk Drive (HDD), and the feasibility of thermal actuation for precision micro motion and positioning in general. The fast dynamics of the micro actuator allows it t

  11. An Algorithm for Positive Definite Least Square Estimation of Parameters.

    Science.gov (United States)

    1986-05-01

    This document presents an algorithm for positive definite least square estimation of parameters. This estimation problem arises from the PILOT...dynamic macro-economic model and is equivalent to an infinite convex quadratic program. It differs from ordinary least square estimations in that the

  12. Thermal Actuation for Precision Micro Motion and Positioning

    NARCIS (Netherlands)

    Paalvast, S.L.

    2010-01-01

    The primary goal of this research was to study the feasibility of a thermal micro actuator for improved tracking performance of a Hard Disk Drive (HDD), and the feasibility of thermal actuation for precision micro motion and positioning in general. The fast dynamics of the micro actuator allows it t

  13. Community detection in networks with positive and negative links

    NARCIS (Netherlands)

    Traag, V.A.; Bruggeman, J.

    2009-01-01

    Detecting communities in complex networks accurately is a prime challenge, preceding further analyses of network characteristics and dynamics. Until now, community detection took into account only positively valued links, while many actual networks also feature negative links. We extend an existing

  14. A New Positioning Algorithm for Position-Sensitive Avalanche Photodiodes.

    Science.gov (United States)

    Zhang, Jin; Olcott, Peter D; Levin, Craig S

    2007-06-01

    We are using a novel position sensitive avalanche photodiode (PSAPD) for the construction of a high resolution positron emission tomography (PET) camera. Up to now most researchers working with PSAPDs have been using an Anger-like positioning algorithm involving the four corner readout signals of the PSAPD. This algorithm yields a significant non-linear spatial "pin-cushion" distortion in raw crystal positioning histograms. In this paper, we report an improved positioning algorithm, which combines two diagonal corner signals of the PSAPD followed by a 45° rotation to determine the X or Y position of the interaction. We present flood positioning histogram data generated with the old and new positioning algorithms using a 3 × 4 array of 2 × 2 × 3 mm(3) and a 3 × 8 array of 1 × 1 × 3 mm(3) of LSO crystals coupled to 8 × 8 mm(2) PSAPDs. This new algorithm significantly reduces the pin-cushion distortion in raw flood histogram image.

  15. Neutral position of persistent direction-changing positional nystagmus.

    Science.gov (United States)

    Ichijo, Hiroaki

    2016-02-01

    The aim of this study was to measure the neutral position of direction-changing apogeotropic positional nystagmus (heavy cupula of the horizontal semicircular canal) and persistent direction-changing geotropic positional nystagmus (light cupula of the horizontal semicircular canal). We conducted a prospective case series study on 31 patients with heavy cupula (12 males, 19 females; mean age, 64.3 years) and 33 patients with light cupula (10 males, 23 females; mean age, 60.9 years). We measured the angle of the neutral position in patients with heavy cupula (θ 1) and that in patients with light cupula (θ 2) using a large protractor. The mean value and standard deviation of θ 1 was 31.6 ± 22.4°, minimum value was 5°, and maximum value was 89°. The mean value and standard deviation of θ 2 was 44.4 ± 20.5°, minimum value was 5°, and maximum value was 85°. θ 2 was significantly greater than θ 1 (p < 0.05). The neutral position varies widely. Some patients exhibit a great angle (more than 40°); therefore, examiners should make patients adopt a completely lateral position in the supine head roll test and should confirm the direction of nystagmus in order to avoid mistaking positional nystagmus for spontaneous nystagmus.

  16. Internetwork dynamics

    NARCIS (Netherlands)

    Rutten, R.J.

    1995-01-01

    This review places current research in quiet-Sun chromospheric dynamics in the context of past and future work, concentrating on observational aspects of three-minute oscillations and Ca II K2V grains. The subject is of interest at present because observations and simulations come together to permit

  17. Structural dynamics

    CERN Document Server

    Strømmen, Einar N

    2014-01-01

    This book introduces to the theory of structural dynamics, with focus on civil engineering structures that may be described by line-like beam or beam-column type of systems, or by a system of rectangular plates. Throughout this book the mathematical presentation contains a classical analytical description as well as a description in a discrete finite element format, covering the mathematical development from basic assumptions to the final equations ready for practical dynamic response predictions. Solutions are presented in time domain as well as in frequency domain. Structural Dynamics starts off at a basic level and step by step brings the reader up to a level where the necessary safety considerations to wind or horizontal ground motion induced dynamic design problems can be performed. The special theory of the tuned mass damper has been given a comprehensive treatment, as this is a theory not fully covered elsewhere. For the same reason a chapter on the problem of moving loads on beams has been included.

  18. Coastal Dynamics

    NARCIS (Netherlands)

    Bakker, W.T.

    1998-01-01

    This book deals on "Coastal Dynamics", which will be defined in a narrow sense as a mathematical theory, which starts from given equations of motion for the sediment, which leads with the continuity equation and given boundary conditions to a calculated (eventually schematized) coastal topography,

  19. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  20. Glassy Dynamics

    DEFF Research Database (Denmark)

    Jensen, Henrik J.; Sibani, Paolo

    2007-01-01

    The term glassy dynamics is often used to refer to the extremely slow relaxation observed in several types of many component systems. The time span needed to reach a steady, time independent, state will typically be far beyond experimentally accessible time scales. When melted alloys are cooled d...

  1. Dynamic LIMIDS

    NARCIS (Netherlands)

    Díez, F.J.; Gerven, M.A.J. van

    2011-01-01

    One of the objectives of artificial intelligence is to build decision-support models for systems that evolve over time and include several types of uncertainty. Dynamic limited-memory influence diagrams (DLIMIDs) are a new type of model proposed recently for this kind of problems. DLIMIDs are simila

  2. Dynamic LIMIDS

    NARCIS (Netherlands)

    Díez, F.J.; Gerven, M.A.J. van

    2011-01-01

    One of the objectives of artificial intelligence is to build decision-support models for systems that evolve over time and include several types of uncertainty. Dynamic limited-memory influence diagrams (DLIMIDs) are a new type of model proposed recently for this kind of problems. DLIMIDs are simila

  3. Record dynamics

    DEFF Research Database (Denmark)

    Robe, Dominic M.; Boettcher, Stefan; Sibani, Paolo

    2016-01-01

    -facto irreversible and become increasingly harder to achieve. Thus, a progression of record-sized dynamical barriers are traversed in the approach to equilibration. Accordingly, the statistics of the events is closely described by a log-Poisson process. Originally developed for relaxation in spin glasses...

  4. System Dynamics

    Science.gov (United States)

    Morecroft, John

    System dynamics is an approach for thinking about and simulating situations and organisations of all kinds and sizes by visualising how the elements fit together, interact and change over time. This chapter, written by John Morecroft, describes modern system dynamics which retains the fundamentals developed in the 1950s by Jay W. Forrester of the MIT Sloan School of Management. It looks at feedback loops and time delays that affect system behaviour in a non-linear way, and illustrates how dynamic behaviour depends upon feedback loop structures. It also recognises improvements as part of the ongoing process of managing a situation in order to achieve goals. Significantly it recognises the importance of context, and practitioner skills. Feedback systems thinking views problems and solutions as being intertwined. The main concepts and tools: feedback structure and behaviour, causal loop diagrams, dynamics, are practically illustrated in a wide variety of contexts from a hot water shower through to a symphony orchestra and the practical application of the approach is described through several real examples of its use for strategic planning and evaluation.

  5. Classical dynamics

    CERN Document Server

    Greenwood, Donald T

    1997-01-01

    Graduate-level text for science and technology students provides strong background in the more abstract and intellectually satisfying areas of dynamical theory. Topics include d'Alembert's principle and the idea of virtual work, Hamilton's equations, Hamilton-Jacobi theory, canonical transformations, more. Problems and references at chapter ends.

  6. Internetwork dynamics

    NARCIS (Netherlands)

    Rutten, R.J.

    2001-01-01

    This review places current research in quiet-Sun chromospheric dynamics in the context of past and future work, concentrating on observational aspects of three-minute oscillations and Ca II K2V grains. The subject is of interest at present because observations and simulations come together to permit

  7. Mitotic dynamics

    Institute of Scientific and Technical Information of China (English)

    唐孝威

    1996-01-01

    A new model for mitotic dynamics of eukaryotic cells is proposed. In the kinetochore mo-tor-midzone motor model two kinds of motors, the kinetochore motors and the midzone motors, play important roles in chromosome movement. Using this model the chromosome congression during prometaphase, the chromosome oscillation during metaphase and the chromatid segregation during anaphase are described in a unified way.

  8. Positive operator semigroups from finite to infinite dimensions

    CERN Document Server

    Bátkai, András; Rhandi, Abdelaziz

    2017-01-01

    This book gives a gentle but up-to-date introduction into the theory of operator semigroups (or linear dynamical systems), which can be used with great success to describe the dynamics of complicated phenomena arising in many applications. Positivity is a property which naturally appears in physical, chemical, biological or economic processes. It adds a beautiful and far reaching mathematical structure to the dynamical systems and operators describing these processes. In the first part, the finite dimensional theory in a coordinate-free way is developed, which is difficult to find in literature. This is a good opportunity to present the main ideas of the Perron-Frobenius theory in a way which can be used in the infinite dimensional situation. Applications to graph matrices, age structured population models and economic models are discussed. The infinite dimensional theory of positive operator semigroups with their spectral and asymptotic theory is developed in the second part. Recent applications illustrate t...

  9. Studies on Precise Spacecraft Navigation and Positioning Using GPS

    Institute of Scientific and Technical Information of China (English)

    XiangKaiheng; QuGuangji

    2004-01-01

    GPS measurement technology, Encke method to solve satellite orbit perturbation and generalized Kalman filtering technology are organically combined together, and an innovative solution—carrier phase & pseudorange integrated dynamic orbit determination (CPPIDOD) for low earth orbit spacecraft on-board autonomous precise navigation and positioning by using GPS is presented. The difficult problems of dynamically resolving integer ambiguities and amendment of cycle slips in the application of GPS carrier phase have been solved.Based on all above, the technique of carrier phase & pseudorange integrated dynamic differential relative navigation between two spacecrafts is brought forward. Results of numerical simulation analyses and senti-physical simulation tests show that the solutions presented in this paper are feasible, which can significantly improve the performance of GPS positioning, and the models, algorithms and software are practical for engineering use.

  10. Integrity & sport events: Position paper

    NARCIS (Netherlands)

    Hover, P.; Dijk, B.; Breedveld, K.; Eekeren, F. van

    2016-01-01

    Sport events are appreciated as important sources of inspiration and positive energy. Yet, for a growing number of people, the negative aspects of sport events have come to cast a shadow over sport events as a positive experience. Questions and doubts have been raised about the transparency and good

  11. Positioning intermediary organisations in innovation

    NARCIS (Netherlands)

    Lente, van H.; Boon, W.P.C.; Klerkx, L.W.A.

    2010-01-01

    Abstract: Intermediary organisations are important in innovation systems and their contributions seem to increase. The central ambition of this paper is to understand and analyse the position of intermediaries within innovation networks. We use so-called positioning theory, where roles are outcomes

  12. Helicopter Payload Position Sensor Investigation

    Science.gov (United States)

    1974-11-01

    terminal guidance, navigational position determination, and machine tooling precision position measurement), and (3) frequency modulation (FM) of the...cable tensometer to measure cable tension at all times. This device rides on the cible but is anchoreC to the aircraft. The results of this

  13. Positive Parenting and Challenging Children

    Science.gov (United States)

    Knoll, Melissa

    2007-01-01

    Positive parenting focuses on developing proactive ways to teach and reinforce desirable behaviors, as opposed to focusing on reacting to and attempting to decrease negative behaviors. Dr. Sheldon Braaten, Executive Director of Behavioral Institute for Children and Adolescents, offers some keys for setting up and using a positive reinforcement…

  14. Signature Strengths in Positive Psychology

    Science.gov (United States)

    Molony, Terry; Henwood, Maureen

    2010-01-01

    Positive psychology can be thought of as the scientific study of what is "right about people" as opposed to the traditional focus on the healing of psychological pain or trauma. The philosophical roots of positive psychology can be traced back to Confucianism, Taoism, Buddhism, Hinduism, Judaism, Christianity, as well as Islamic and Athenian…

  15. Indoor Positioning System using Bluetooth

    OpenAIRE

    Sahil Puri

    2015-01-01

    This Paper on Bluetooth Indoor Positioning System is the intersection of Bluetooth Technology and Indoor Positioning Systems. Almost every smartphone today is Bluetooth enabled, making the use of the technology more flexible. We aim at using the RSSI value of Bluetooth signals to track the location of a device.

  16. Indoor Positioning System using Bluetooth

    OpenAIRE

    Sahil Puri

    2015-01-01

    This Paper on Bluetooth Indoor Positioning System is the intersection of Bluetooth Technology and Indoor Positioning Systems. Almost every smartphone today is Bluetooth enabled, making the use of the technology more flexible. We aim at using the RSSI value of Bluetooth signals to track the location of a device.

  17. Signature Strengths in Positive Psychology

    Science.gov (United States)

    Molony, Terry; Henwood, Maureen

    2010-01-01

    Positive psychology can be thought of as the scientific study of what is "right about people" as opposed to the traditional focus on the healing of psychological pain or trauma. The philosophical roots of positive psychology can be traced back to Confucianism, Taoism, Buddhism, Hinduism, Judaism, Christianity, as well as Islamic and Athenian…

  18. HIV-positive people, HIV-negative partners.

    Science.gov (United States)

    Harmon, L; Volker, M

    1995-01-01

    More relationships exist today between HIV-positive and HIV-negative partners. This article explores the underlying dynamics that might account for this phenomenon. Codependency theories may explain these relationships for some couples. For other couples, it is suggested that positive-negative homosexual relationships may be influenced by both unhealthy and healthy gay developmental experiences as well as by a sense of compassion. The article addresses both HIV-positive people choosing HIV-negative partners and vice versa. Treatment issues for the various theories are discussed and recommendations are made.

  19. Precise perception of virtual object position in real world

    Institute of Scientific and Technical Information of China (English)

    Lin Liping; Wu Pingdong; Huang Jie; Li Jian

    2009-01-01

    There is a deviation between actual and theoretical perceived positions of virtual object in stereoscopic display. Therefore, methods for precise position perception in real world are proposed in this paper. The causes for the deviation are analyzed on the basis of geometrical optics. Then deviation corrections are performed by error compensation with mathematic method and by remodeling virtual viewpoint dynamically with the movement of physical viewpoint. Experimental results show that these methods can reduce the position deviation to less than 10 millimeter, meeting the requirements for direct manipulation in multi-sensory virtual environment.

  20. Modeling And Position Control Of Scara Type 3D Printer

    Directory of Open Access Journals (Sweden)

    Ahmet Saygamp305n Ogulmuamp351

    2015-08-01

    Full Text Available In this work a scara robot type 3D printer system is dynamically modeled and position control of the system is realized. For this aim computer aided design model of three degrees of freedom robotic system is created using SolidWorks program then obtained model is exported to MATLABSimMechanics software for position control. Also mathematical model of servo motors used in robotic 3D printer system is included in control methodology to design proportional controllers. Uncontrolled and controlled position results are simulated and given in the form of the graphics.

  1. Libera Electron Beam Position Processor

    CERN Document Server

    Ursic, Rok

    2005-01-01

    Libera is a product family delivering unprecedented possibilities for either building powerful single station solutions or architecting complex feedback systems in the field of accelerator instrumentation and controls. This paper presents functionality and field performance of its first member, the electron beam position processor. It offers superior performance with multiple measurement channels delivering simultaneously position measurements in digital format with MHz kHz and Hz bandwidths. This all-in-one product, facilitating pulsed and CW measurements, is much more than simply a high performance beam position measuring device delivering micrometer level reproducibility with sub-micrometer resolution. Rich connectivity options and innate processing power make it a powerful feedback building block. By interconnecting multiple Libera electron beam position processors one can build a low-latency high throughput orbit feedback system without adding additional hardware. Libera electron beam position processor ...

  2. Positivity VII (Zaanen Centennial Conference)

    CERN Document Server

    Pagter, Ben; Gaans, Onno; Veraar, Mark

    2016-01-01

    This book presents the proceedings of Positivity VII, held from 22-26 July 2013, in Leiden, the Netherlands. Positivity is the mathematical field concerned with ordered structures and their applications in the broadest sense of the word. A biyearly series of conferences is devoted to presenting the latest developments in this lively and growing discipline. The lectures at the conference covered a broad spectrum of topics, ranging from order-theoretic approaches to stochastic processes, positive solutions of evolution equations and positive operators on vector lattices, to order structures in the context of algebras of operators on Hilbert spaces. The contributions in the book reflect this variety and appeal to university researchers in functional analysis, operator theory, measure and integration theory and operator algebras. Positivity VII was also the Zaanen Centennial Conference to mark the 100th birth year of Adriaan Cornelis Zaanen, who held the chair of Analysis in Leiden for more than 25 years and was ...

  3. Ultrasonic actuators for nanometre positioning

    Science.gov (United States)

    Snitka

    2000-03-01

    This paper deals with ultrasonic motors based on bimodal plate vibrations and their application to nanometre resolution stepper positioning systems. The concept of a linear ultrasonic motor drive capable of nanometric steps, long-range travel and reversible controlled motion is presented. The motor concept developed is based on the superposition of a longitudinal and bending vibrations of a rectangular resonator. The ultrasonic motor model based on system identification via discrete observations and prediction has been developed for control applications. The control algorithm for ultrasonic motors has been developed and theoretical investigations have been made. The open loop positioning system with designed stepper ultrasonic drive produced 10 nm resolution and 5% displacement repeatability. The system with computer controlled position feedback has shown 0.3 micron positioning accuracy over the 100 mm positioning range.

  4. Introducing positive psychology to SLA

    Directory of Open Access Journals (Sweden)

    Sarah Mercer

    2014-01-01

    Full Text Available Positive psychology is a rapidly expanding subfield in psychology that has important implications for the field of second language acquisition (SLA. This paper introduces positive psychology to the study of language by describing its key tenets. The potential contributions of positive psychology are contextualized with reference to prior work, including the humanistic movement in language teaching, models of motivation, the concept of an affective filter, studies of the good language learner, and the concepts related to the self. There are reasons for both encouragement and caution as studies inspired by positive psychology are undertaken. Papers in this special issue of SSLLT cover a range of quantitative and qualitative methods with implications for theory, research, and teaching practice. The special issue serves as a springboard for future research in SLA under the umbrella of positive psychology.

  5. Positive Amplitudes In The Amplituhedron

    CERN Document Server

    Arkani-Hamed, Nima; Trnka, Jaroslav

    2014-01-01

    The all-loop integrand for scattering amplitudes in planar N = 4 SYM is determined by an "amplitude form" with logarithmic singularities on the boundary of the amplituhedron. In this note we provide strong evidence for a new striking property of the superamplitude, which we conjecture to be true to all loop orders: the amplitude form is positive when evaluated inside the amplituhedron. The statement is sensibly formulated thanks to the natural "bosonization" of the superamplitude associated with the amplituhedron geometry. However this positivity is not manifest in any of the current approaches to scattering amplitudes, and in particular not in the cellulations of the amplituhedron related to on-shell diagrams and the positive grassmannian. The surprising positivity of the form suggests the existence of a "dual amplituhedron" formulation where this feature would be made obvious. We also suggest that the positivity is associated with an extended picture of amplituhedron geometry, with the amplituhedron sitting...

  6. Relativistic Positioning Systems: Numerical Simulations

    CERN Document Server

    Puchades, Neus

    2014-01-01

    The motion of satellite constellations similar to GPS and Galileo is numerically simulated and, then, the region where bifurcation (double positioning) occurs is appropriately represented. In the cases of double positioning, the true location may be found using additional information (angles or times). The zone where the Jacobian, J, of the transformation from inertial to emission coordinates vanishes is also represented and interpreted. It is shown that the uncertainties in the satellite world lines produce positioning errors, which depend on the value of |J|. The smaller this quantity the greater the expected positioning errors. Among all the available 4-tuples of satellites, the most appropriate one -for a given location- should minimize positioning errors (large enough |J| values) avoiding bifurcation. Our study is particularly important to locate objects which are far away from Earth, e.g., satellites.

  7. The condition for dynamic stability

    NARCIS (Netherlands)

    Hof, AL; Gazendam, MGJ; Sinke, WE

    The well-known condition for standing stability in static situations is that the vertical projection of the centre of mass (CoM) should be within the base of support (BoS). On the basis of a simple inverted pendulum model, an extension of this rule is proposed for dynamical situations: the position

  8. The condition for dynamic stability

    NARCIS (Netherlands)

    Hof, AL; Gazendam, MGJ; Sinke, WE

    2005-01-01

    The well-known condition for standing stability in static situations is that the vertical projection of the centre of mass (CoM) should be within the base of support (BoS). On the basis of a simple inverted pendulum model, an extension of this rule is proposed for dynamical situations: the position

  9. Dynamic optical filtration

    Science.gov (United States)

    Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

    2005-01-01

    A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

  10. False positives in cancer epidemiology.

    Science.gov (United States)

    McLaughlin, Joseph K; Tarone, Robert E

    2013-01-01

    A recent attempt to estimate the false-positive rate for cancer epidemiology studies is based on agents in International Agency for Research on Cancer (IARC) category 3 (agent not classifiable as to its carcinogenicity to humans) in the IARC Monographs Program. The estimation method is critiqued regarding biases caused by its reliance on the IARC classification criteria for assessing carcinogenic potential. The privileged position given to epidemiologic studies by the IARC criteria ensures that the percentage of positive epidemiologic studies for an agent will depend strongly on the IARC category to which the agent is assigned. Because IARC category 3 is composed of agents with the lowest-assessed carcinogenic potential to which the estimation approach in question could be applied, a spuriously low estimated false-positive rate was necessarily the outcome of this approach. Tendentious estimation approaches like that employed will by necessity produce spuriously low and misleading false positive rates. The recently reported estimates of the false-positive rate in cancer epidemiology are seriously biased and contribute nothing substantive to the literature on the very real problems related to false-positive findings in epidemiology.

  11. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    profit on well-developed markets. Dynamic participation features on cross asset portfolios are at rst sight a remedy to that dilemma. Based on volatility thresholds and portfolio re-balancing, the fund engineers try to create a "volatility guaranteed" investment opportunity by surfing on the unusual high...... concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex......, interest rates and commodities. If an investor positions himself on the (volatility) market within a long/short trading framework, he typically bets on a traditional mispricing arbitrage. However as this corresponds to a call spread with equal exercise prices, this strategy alone would not generate enough...

  12. Position control system using ER clutch and piezoactuator

    Science.gov (United States)

    Choi, Seung-Bok; Han, Sang-Soo

    2003-08-01

    This paper presents ultra precision positioning system consisting of electrorheological(ER) clutch and piezoelectric actuators using dual servo control mechanism. ER clutch and ball screw are adopted for a coarse positioning stage, and magnification device driven by multi-stack piezoelectric actuator is manufactured for a fine positioning stage. After deriving the dynamic modeling for coarse motion stage, a sliding mode controller is designed to achieve robust control performance. In addition, conventional PID controller incorporated with the hysteresis nonlinearity of the piezoelectric actuator is designed to construct a feed-back with feed-forward control scheme for precise and fast positioning of the fine motion stage. Step regulating control performance of the proposed dual servo system is evaluated via experimental works to verify the effectiveness of the proposed position control system.

  13. Performance of a high resolution cavity beam position monitor system

    Science.gov (United States)

    Walston, Sean; Boogert, Stewart; Chung, Carl; Fitsos, Pete; Frisch, Joe; Gronberg, Jeff; Hayano, Hitoshi; Honda, Yosuke; Kolomensky, Yury; Lyapin, Alexey; Malton, Stephen; May, Justin; McCormick, Douglas; Meller, Robert; Miller, David; Orimoto, Toyoko; Ross, Marc; Slater, Mark; Smith, Steve; Smith, Tonee; Terunuma, Nobuhiro; Thomson, Mark; Urakawa, Junji; Vogel, Vladimir; Ward, David; White, Glen

    2007-07-01

    It has been estimated that an RF cavity Beam Position Monitor (BPM) could provide a position measurement resolution of less than 1 nm. We have developed a high resolution cavity BPM and associated electronics. A triplet comprised of these BPMs was installed in the extraction line of the Accelerator Test Facility (ATF) at the High Energy Accelerator Research Organization (KEK) for testing with its ultra-low emittance beam. The three BPMs were each rigidly mounted inside an alignment frame on six variable-length struts which could be used to move the BPMs in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a robust calibration algorithm which is immune to beam jitter. To date, we have demonstrated a position resolution of 15.6 nm and a tilt resolution of 2.1 μrad over a dynamic range of approximately ±20 μm.

  14. Modelling heat transport through completely positive maps

    CERN Document Server

    Wichterich, H; Gemmer, J; Henrich, M J; Michel, M; Breuer, Heinz-Peter; Gemmer, Jochen; Henrich, Markus J.; Michel, Mathias; Wichterich, Hannu

    2007-01-01

    We investigate heat transport in a spin-1/2 Heisenberg chain, coupled locally to independent thermal baths of different temperature. The analysis is carried out within the framework of the theory of open systems by means of appropriate quantum master equations. The standard microscopic derivation of the weak-coupling Lindblad equation in the secular approximation is considered, and shown to be inadequate for the description of stationary nonequilibrium properties like a non-vanishing energy current. Furthermore, we derive an alternative master equation that is capable to describe a stationary energy current and, at the same time, leads to a completely positive dynamical map. This paves the way for efficient numerical investigations of heat transport in larger systems based on Monte Carlo wave function techniques.

  15. Cylindrical wormholes with positive cosmological constant

    CERN Document Server

    Richarte, Mart'\\in G

    2013-01-01

    We construct cylindrical, traversable wormholes with finite radii by taking into account the cut-and-paste procedure for the case of cosmic string manifolds with a positive cosmological constant. Under reasonable assumptions about the equation of state of the matter located at the shell, we find that the wormhole throat undergoes a monotonous evolution provided it moves at a constant velocity. In order to explore the dynamical nonlinear behaviour of the wormhole throat, we consider that the matter at the shell is supported by anisotropic Chaplygin gas, anti-Chaplygin gas, or a mixed of Chaplygin and anti-Chaplygin gases implying that wormholes could suffer an accelerated expansion or contraction but the oscillatory behavior seems to be forbidden.

  16. Cylindrical wormholes with positive cosmological constant

    Science.gov (United States)

    Richarte, Martín G.

    2013-07-01

    We construct cylindrical, traversable wormholes with finite radii by taking into account the cut-and-paste procedure for the case of cosmic string manifolds with a positive cosmological constant. Under reasonable assumptions about the equation of state of the matter located at the shell, we find that the wormhole throat undergoes a monotonous evolution provided it moves at a constant velocity. In order to explore the dynamical nonlinear behavior of the wormhole throat, we consider that the matter of the shell is supported by anisotropic Chaplygin gas, anti-Chaplygin gas, or a mixture of Chaplygin and anti-Chaplygin gases, implying that wormholes could suffer an accelerated expansion or contraction, but that oscillatory behavior seems to be forbidden.

  17. Dynamic Dazzle Distorts Speed Perception.

    Directory of Open Access Journals (Sweden)

    Joanna R Hall

    Full Text Available Static high contrast ('dazzle' patterns, such as zigzags, have been shown to reduce the perceived speed of an object. It has not escaped our notice that this effect has possible military applications and here we report a series of experiments on humans, designed to establish whether dynamic dazzle patterns can cause distortions of perceived speed sufficient to provide effective defence in the field, and the extent to which these effects are robust to a battery of manipulations. Dynamic stripe patterns moving in the same direction as the target are found to increase the perceived speed of that target, whilst dynamic stripes moving in the opposite direction to the target reduce the perceived speed. We establish the optimum position for such dazzle patches; confirm that reduced contrast and the addition of colour do not affect the performance of the dynamic dazzle, and finally, using the CO2 challenge, show that the effect is robust to stressful conditions.

  18. Positive Identity as a Positive Youth Development Construct: A Conceptual Review

    Directory of Open Access Journals (Sweden)

    Sandra K. M. Tsang

    2012-01-01

    Full Text Available Identity is a core construct in psychology because it refers to how a person addresses issues dealing with who that person is. Important theorists studying the concept of identity, like Erikson, Marcia, and Higgins, assert that identity is organized,is learned, and is dynamic, and a subjective evaluation of an individual’s identity has emotional consequences for that individual. Adolescents who can cultivate a clear and positive identity after their developmental struggles during adolescence often advance more smoothly into adulthood. This paper reviews literature on the nature and structure of identity and examines its importance on adolescent developmental outcomes. It traces significant determinants of identity and proposes strategies for cultivation of positive identity. Observations on current research gaps in the study of identity and future research directions will also be discussed.

  19. Applied dynamics

    CERN Document Server

    Schiehlen, Werner

    2014-01-01

    Applied Dynamics is an important branch of engineering mechanics widely applied to mechanical and automotive engineering, aerospace and biomechanics as well as control engineering and mechatronics. The computational methods presented are based on common fundamentals. For this purpose analytical mechanics turns out to be very useful where D’Alembert’s principle in the Lagrangian formulation proves to be most efficient. The method of multibody systems, finite element systems and continuous systems are treated consistently. Thus, students get a much better understanding of dynamical phenomena, and engineers in design and development departments using computer codes may check the results more easily by choosing models of different complexity for vibration and stress analysis.

  20. Fluid dynamics

    CERN Document Server

    Bernard, Peter S

    2015-01-01

    This book presents a focused, readable account of the principal physical and mathematical ideas at the heart of fluid dynamics. Graduate students in engineering, applied math, and physics who are taking their first graduate course in fluids will find this book invaluable in providing the background in physics and mathematics necessary to pursue advanced study. The book includes a detailed derivation of the Navier-Stokes and energy equations, followed by many examples of their use in studying the dynamics of fluid flows. Modern tensor analysis is used to simplify the mathematical derivations, thus allowing a clearer view of the physics. Peter Bernard also covers the motivation behind many fundamental concepts such as Bernoulli's equation and the stream function. Many exercises are designed with a view toward using MATLAB or its equivalent to simplify and extend the analysis of fluid motion including developing flow simulations based on techniques described in the book.