WorldWideScience

Sample records for augmented generator control

  1. A new strategy for transient stability using augmented generator control and local dynamic braking

    Energy Technology Data Exchange (ETDEWEB)

    Dorsey, J.; Jiang, H.; Habetler, T. [Georgia Inst. of Tech., Atlanta, GA (United States); Qu, Z. [University of Central Florida, Orlando, FL (United States)

    1994-12-31

    A decentralized automatic control strategy for significantly improving the transient stability of a large power system is introduced. The strategy combines local dynamic braking and a straightforward augmentation of the existing turbine / governor control system that uses only local feedback. The brake resistor, which employs thick film, metal oxide technology, has no inductance and is of very low resistance, allowing its use during fault to show a generator`s acceleration. Simulation results using the 39 Bus New England system show that the strategy dramatically increases the global stability of a power system. (author) 15 refs., 7 figs., 1 tab.

  2. Issues of Mitigation Strategies in Augmented System for Next Generation Control Room

    Energy Technology Data Exchange (ETDEWEB)

    Tuan Q. Tran

    2007-08-01

    Past research on augmented systems has been predominately concerned with measuring and classifying an operator’s functional states. Only recently has the field begun researching mitigation strategies. The purpose of this paper is to add further conceptual understanding to mitigation strategies. Based upon the decision making literature, we pose three issues that mitigation strategies need to resolve: the types of decision strategies an operator uses, the structure of the information that an operator processes, and finally, the cue or pattern of cues that the operator relies on in making decisions. These issues are important to ensure that mitigation strategies are congruent to operator’s decision-making behaviors.

  3. Augmented Lagrangian Method For Discretized Optimal Control ...

    African Journals Online (AJOL)

    With the aid of Augmented Lagrangian method, a quadratic function with a control operator (penalized matrix) amenable to conjugate gradient method is generated. Numerical experiments verify the efficiency of the proposed technique which compares much more favourably to the existing scheme. Keywords: Trapezoidal ...

  4. Third-generation percutaneous vertebral augmentation systems.

    Science.gov (United States)

    Vanni, Daniele; Galzio, Renato; Kazakova, Anna; Pantalone, Andrea; Grillea, Giovanni; Bartolo, Marcello; Salini, Vincenzo; Magliani, Vincenzo

    2016-03-01

    Currently, there is no general consensus about the management of osteoporotic vertebral fractures (OVF). In the past, conservative treatment for at least one month was deemed appropriate for the majority of vertebral fractures. When pain persisted after conservative treatment, it was necessary to consider surgical interventions including: vertebroplasty for vertebral fractures with less than 30% loss of height of the affected vertebral body and kyphoplasty for vertebral fractures with greater than 30% loss of height. Currently, this type of treatment is not feasible. Herein we review the characteristics and methods of operation of three of the most common percutaneous vertebral augmentation systems (PVAS) for the treatment of OVF: Vertebral Body Stenting(®) (VBS), OsseoFix(®) and Spine Jack(®). VBS is a titanium device accompanied by a hydraulic (as opposed to mechanical) working system which allows a partial and not immediate possibility to control the opening of the device. On the other hand, OsseoFix(®) and Spine Jack(®) are accompanied by a mechanical working system which allows a progressive and controlled reduction of the vertebral fracture. Another important aspect to consider is the vertebral body height recovery. OsseoFix(®) has an indirect mechanism of action: the compaction of the trabecular bone causes an increase in the vertebral body height. Unlike the Vertebral Body Stenting(®) and Spine Jack(®), the OsseoFix(®) has no direct lift mechanism. Therefore, for these characteristics and for the force that this device is able to provide. In our opinion, Spine Jack(®) is the only device also suitable for the treatment OVF, traumatic fracture (recent, old or inveterate) and primary or secondary bone tumors.

  5. Telerobotic control with stereoscopic augmented reality

    Science.gov (United States)

    Rastogi, Anu; Milgram, Paul; Drascic, David; Grodski, Julius J.

    1996-04-01

    Teleoperation in unstructured environments is conventionally restricted to direct manual control of the robot. Under such circumstances operator performance can be affected by inadequate visual feedback from the remote site, caused by, for example, limitations in the bandwidth of the communication channel. This paper introduces ARTEMIS (Augmented Reality TEleManipulation Interface System), a new display interface for enabling local teleoperation task simulation. An important feature of the interface is that the display can be generated in the absence of a model of the remote operating site. The display consists of a stereographical model of the robot overlaid on real stereovideo images from the remote site. This stereographical robot is used to simulate manipulation with respect to objects visible in the stereovideo image, following which sequences of robot control instructions can be transmitted to the remote site. In the present system, the update rate of video images can be very low, since continuous feedback is no longer needed for direct manual control of the robot. Several features of the system are presented and its advantages discussed, together with an illustrative example of a pick-and-place task.

  6. Fault Tree Generation and Augmentation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fault Management (FM) is one of the key components of system autonomy. In order to guarantee FM effectiveness and control the cost, tools are required to automate...

  7. Mechanical Augmentation Channel Design for Turbine Current Generators

    Directory of Open Access Journals (Sweden)

    E. García

    2014-04-01

    Full Text Available We present the design and analysis of augmentation channels to increase the efficiency of shrouded marine current turbines in conditions of low intensity flows. These turbines are part of a prototype of a floating device composed of wind and marine current generators for generating renewable energy. It intends to exploit renewable energy resources in an integrated manner using wind and current turbines in offshore plants optimizing the economic investment.

  8. Augmentative biological control of arthropods in Latin America

    NARCIS (Netherlands)

    Lenteren, van J.C.; Bueno, V.H.P.

    2003-01-01

    Augmentative forms of biological control, where natural enemies are periodically introduced, are applied over large areas in various cropping systems in Latin America. About 25% of the world area under augmentative control is situated in this region. Well-known examples are the use of species of the

  9. Research on Design of MUH Attitude Stability Augmentation Control System

    Science.gov (United States)

    Fan, Shigang

    2017-09-01

    Attitude stability augmentation control system with a lower cost need to be designed so that MUH (Mini Unmanned Helicopter) can adapt to different types of geographic environment and fly steadily although the weather may be bad. Attitude feedback was calculated mainly by filtering estimation within attitude acquisition module in this system. Stability augmentation can be improved mainly by PI. This paper will depict running principle and designing process of MUH attitude stability augmentation control system and algorithm that is considered as an important part in this system.

  10. Aircraft Control Augmentation and Health Monitoring Using FADS Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I research proposal is aimed at demonstrating the feasibility of an innovative architecture comprising control augmentation and on-line health monitoring...

  11. Digital control of highly augmented combat rotorcraft

    Science.gov (United States)

    Tischler, Mark B.

    1987-01-01

    Proposed concepts for the next generation of combat helicopters are to be embodied in a complex, highly maneuverable, multiroled vehicle with avionics systems. Single pilot and nap-of-the-Earth operations require handling qualities which minimize the involvement of the pilot in basic stabilization tasks. To meet these requirements will demand a full authority, high-gain, multimode, multiply-redundant, digital flight-control system. The gap between these requirements and current low-authority, low-bandwidth operational rotorcraft flight-control technology is considerable. This research aims at smoothing the transition between current technology and advanced concept requirements. The state of the art of high-bandwidth digital flight-control systems are reviewed; areas of specific concern for flight-control systems of modern combat are exposed; and the important concepts are illustrated in design and analysis of high-gain, digital systems with a detailed case study involving a current rotorcraft system. Approximate and exact methods are explained and illustrated for treating the important concerns which are unique to digital systems.

  12. Augmenting a TV Broadcast with Synchronised User Generated Video and Relevant Social Network Content

    NARCIS (Netherlands)

    Stokking, H.M.; Veenhuizen, A.T.; Kaptein, A.M.; Niamut, O.A.

    2014-01-01

    As TNO, we have developed an Augmented Live Broadcast use case, using components from the FP7 STEER project. In this use case, a television broadcast of a live event is augmented with user generated content. This user generated content consists of videos made by users at the event, and also of

  13. Effect of continuous rearing on courtship acoustics of five braconid parasitoids, candidates for augmentative biological control of Anastrepha species

    Science.gov (United States)

    The courtship acoustics of five species of parasitoid wasps (Hymenoptera: Braconidae), potential candidates for augmentative biological control of Anastrepha species (Diptera: Tephritidae), were compared between recently colonized individuals and those continuously reared 70-148 generations. During...

  14. Experimental Investigations of Generalized Predictive Control for Tiltrotor Stability Augmentation

    Science.gov (United States)

    Nixon, Mark W.; Langston, Chester W.; Singleton, Jeffrey D.; Piatak, David J.; Kvaternik, Raymond G.; Bennett, Richard L.; Brown, Ross K.

    2001-01-01

    A team of researchers from the Army Research Laboratory, NASA Langley Research Center (LaRC), and Bell Helicopter-Textron, Inc. have completed hover-cell and wind-tunnel testing of a 1/5-size aeroelastically-scaled tiltrotor model using a new active control system for stability augmentation. The active system is based on a generalized predictive control (GPC) algorithm originally developed at NASA LaRC in 1997 for un-known disturbance rejection. Results of these investigations show that GPC combined with an active swashplate can significantly augment the damping and stability of tiltrotors in both hover and high-speed flight.

  15. Augmenting a TV Broadcast with Synchronised User Generated Video and Relevant Social Network Content

    OpenAIRE

    Stokking, H.M.; Veenhuizen, A.T.; Kaptein, A.M.; Niamut, O.A.

    2014-01-01

    As TNO, we have developed an Augmented Live Broadcast use case, using components from the FP7 STEER project. In this use case, a television broadcast of a live event is augmented with user generated content. This user generated content consists of videos made by users at the event, and also of relevant social network content. The current implementation uses timestamps inserted in the media streams to synchronise related media streams. Social networks are searched using EPG information as a st...

  16. Dynamics and control of Lorentz-augmented spacecraft relative motion

    CERN Document Server

    Yan, Ye; Yang, Yueneng

    2017-01-01

    This book develops a dynamical model of the orbital motion of Lorentz spacecraft in both unperturbed and J2-perturbed environments. It explicitly discusses three kinds of typical space missions involving relative orbital control: spacecraft hovering, rendezvous, and formation flying. Subsequently, it puts forward designs for both open-loop and closed-loop control schemes propelled or augmented by the geomagnetic Lorentz force. These control schemes are entirely novel and represent a significantly departure from previous approaches.

  17. Model reference adaptive control and adaptive stability augmentation

    DEFF Research Database (Denmark)

    Henningsen, Arne; Ravn, Ole

    1993-01-01

    stability augmented model reference design is proposed. By utilizing the closed-loop control error, a simple auxiliary controller is tuned, using a normalized MIT rule for the parameter adjustment. The MIT adjustment is protected against the effects of unmodelled dynamics by lowpass filtering...... of the gradient. The proposed method is verified through simulation results indicating that the method may lead to an improvement of the model reference controller in the presence of unmodelled dynamics...

  18. Augmented Lagrangian Method For Discretized Optimal Control ...

    African Journals Online (AJOL)

    In this paper, we are concerned with one-dimensional time invariant optimal control problem, whose objective function is quadratic and the dynamical system is a differential equation with initial condition .Since most real life problems are nonlinear and their analytical solutions are not readily available, we resolve to ...

  19. Automatically Augmenting Lifelog Events Using Pervasively Generated Content from Millions of People

    Directory of Open Access Journals (Sweden)

    Alan F. Smeaton

    2010-02-01

    Full Text Available In sensor research we take advantage of additional contextual sensor information to disambiguate potentially erroneous sensor readings or to make better informed decisions on a single sensor’s output. This use of additional information reinforces, validates, semantically enriches, and augments sensed data. Lifelog data is challenging to augment, as it tracks one’s life with many images including the places they go, making it non-trivial to find associated sources of information. We investigate realising the goal of pervasive user-generated content based on sensors, by augmenting passive visual lifelogs with “Web 2.0” content collected by millions of other individuals.

  20. Automatically augmenting lifelog events using pervasively generated content from millions of people.

    Science.gov (United States)

    Doherty, Aiden R; Smeaton, Alan F

    2010-01-01

    In sensor research we take advantage of additional contextual sensor information to disambiguate potentially erroneous sensor readings or to make better informed decisions on a single sensor's output. This use of additional information reinforces, validates, semantically enriches, and augments sensed data. Lifelog data is challenging to augment, as it tracks one's life with many images including the places they go, making it non-trivial to find associated sources of information. We investigate realising the goal of pervasive user-generated content based on sensors, by augmenting passive visual lifelogs with "Web 2.0" content collected by millions of other individuals.

  1. Space Launch System Implementation of Adaptive Augmenting Control

    Science.gov (United States)

    Wall, John H.; Orr, Jeb S.; VanZwieten, Tannen S.

    2014-01-01

    Given the complex structural dynamics, challenging ascent performance requirements, and rigorous flight certification constraints owing to its manned capability, the NASA Space Launch System (SLS) launch vehicle requires a proven thrust vector control algorithm design with highly optimized parameters to provide stable and high-performance flight. On its development path to Preliminary Design Review (PDR), the SLS flight control system has been challenged by significant vehicle flexibility, aerodynamics, and sloshing propellant. While the design has been able to meet all robust stability criteria, it has done so with little excess margin. Through significant development work, an Adaptive Augmenting Control (AAC) algorithm has been shown to extend the envelope of failures and flight anomalies the SLS control system can accommodate while maintaining a direct link to flight control stability criteria such as classical gain and phase margin. In this paper, the work performed to mature the AAC algorithm as a baseline component of the SLS flight control system is presented. The progress to date has brought the algorithm design to the PDR level of maturity. The algorithm has been extended to augment the full SLS digital 3-axis autopilot, including existing load-relief elements, and the necessary steps for integration with the production flight software prototype have been implemented. Several updates which have been made to the adaptive algorithm to increase its performance, decrease its sensitivity to expected external commands, and safeguard against limitations in the digital implementation are discussed with illustrating results. Monte Carlo simulations and selected stressing case results are also shown to demonstrate the algorithm's ability to increase the robustness of the integrated SLS flight control system.

  2. Synthesis of the unmanned aerial vehicle remote control augmentation system

    Energy Technology Data Exchange (ETDEWEB)

    Tomczyk, Andrzej, E-mail: A.Tomczyk@prz.edu.pl [Department of Avionics and Control Systems, Faculty of Mechanical Engineering and Aeronautics, Rzeszów University of Technology, Al. Powstañców Warszawy 12, 35-959 Rzeszów (Poland)

    2014-12-10

    Medium size Unmanned Aerial Vehicle (UAV) usually flies as an autonomous aircraft including automatic take-off and landing phases. However in the case of the on-board control system failure, the remote steering is using as an emergency procedure. In this reason, remote manual control of unmanned aerial vehicle is used more often during take-of and landing phases. Depends on UAV take-off mass and speed (total energy) the potential crash can be very danger for airplane and environment. So, handling qualities of UAV is important from pilot-operator point of view. In many cases the dynamic properties of remote controlling UAV are not suitable for obtaining the desired properties of the handling qualities. In this case the control augmentation system (CAS) should be applied. Because the potential failure of the on-board control system, the better solution is that the CAS algorithms are placed on the ground station computers. The method of UAV handling qualities shaping in the case of basic control system failure is presented in this paper. The main idea of this method is that UAV reaction on the operator steering signals should be similar - almost the same - as reaction of the 'ideal' remote control aircraft. The model following method was used for controller parameters calculations. The numerical example concerns the medium size MP-02A UAV applied as an aerial observer system.

  3. New perspective for third generation percutaneous vertebral augmentation procedures: Preliminary results at 12 months.

    Science.gov (United States)

    Vanni, Daniele; Pantalone, Andrea; Bigossi, Francesco; Pineto, Filippo; Lucantoni, Danilo; Salini, Vincenzo

    2012-07-01

    The prevalence of osteoporotic vertebral fractures (OVF) increased in the last years. Compression fractures promote a progressive spine kyphosis increase, resulting in a weight shift and anterior column overload, with OVF additional risk (domino effect). The aim of this study is to evaluate the OVF treatment outcome using Spine Jack(®), a titanium device for third generation percutaneous vertebral augmentation procedures (PVAPs). From February 2010, a prospective randomized study was performed examining 300 patients who underwent PVAP due to OVF type A1 according to Magerl/AO spine classification. Patients enrolled in the study were divided in two homogenous groups with regards to age (65-85 years), sex, and general clinical findings. Group A included 150 patients who underwent PVAP using Spine Jack(®) system; the second, group B (control group), included 150 patients treated by conventional balloon kyphoplasty. Patients underwent a clinical (visual analogue scale and Oswestry disability index) and radiographic follow-up, with post-operative standing plain radiogram of the spine at 1, 6, and 12 months. The radiographic parameters that were taken into account were: Post-operative anterior vertebral body height, pre-operative anterior vertebral body height, cephalic anterior vertebral body height, and caudal anterior vertebral body height. Compared to the Spine Jack(®) group, the kyphoplasty group required a little longer operation time (an average of 40 min-group A vs. 45 min-group B, P Jack(®) group than in the kyphoplasty group (P Jack(®) has some new features compared to other systems: It is equipped with a mechanical and not a hydraulic opening control; this ensures a gradual and controlled vertebral fracture reduction. In our study, we demonstrated that the third generation PVAP with Spine Jack(®) is able to determine a safe vertebral body height restoration compared to the conventional balloon kyphoplasty.

  4. the use of augmented reality in command and control situation ...

    African Journals Online (AJOL)

    Abel

    Augmented reality is not completely new technology, but rather an interesting combination of existing technologies, ... Augmented reality applications are becoming more popular due to the remarkable progress in ultra-mobile ..... 1) increased loading on operators to provide status reports;. 2) dissemination of status reports;.

  5. New perspective for third generation percutaneous vertebral augmentation procedures: Preliminary results at 12 months

    Directory of Open Access Journals (Sweden)

    Daniele Vanni

    2012-01-01

    Full Text Available Introduction: The prevalence of osteoporotic vertebral fractures (OVF increased in the last years. Compression fractures promote a progressive spine kyphosis increase, resulting in a weight shift and anterior column overload, with OVF additional risk (domino effect. The aim of this study is to evaluate the OVF treatment outcome using Spine Jack ®, a titanium device for third generation percutaneous vertebral augmentation procedures (PVAPs. Materials and Methods: From February 2010, a prospective randomized study was performed examining 300 patients who underwent PVAP due to OVF type A1 according to Magerl/AO spine classification. Patients enrolled in the study were divided in two homogenous groups with regards to age (65-85 years, sex, and general clinical findings. Group A included 150 patients who underwent PVAP using Spine Jack ® system; the second, group B (control group, included 150 patients treated by conventional balloon kyphoplasty. Patients underwent a clinical (visual analogue scale and Oswestry disability index and radiographic follow-up, with post-operative standing plain radiogram of the spine at 1, 6, and 12 months. The radiographic parameters that were taken into account were: Post-operative anterior vertebral body height, pre-operative anterior vertebral body height, cephalic anterior vertebral body height, and caudal anterior vertebral body height. Results: Compared to the Spine Jack ® group, the kyphoplasty group required a little longer operation time (an average of 40 min-group A vs. 45 min-group B, P < 0.05 and a greater amount of polymethylmethacrylate (4.0 mL-group A vs. 5.0 mL-group B, P < 0.05;. The post-operative increase in vertebral body height was greater in the Spine Jack ® group than in the kyphoplasty group (P < 0.05. Discussion: PVAP are based on the cement injection into the vertebral body. Vertebroplasty does not allow the vertebral body height recovery. Balloon kyphoplasty allows a temporary height

  6. Use of augmented reality in command and control situation awareness

    CSIR Research Space (South Africa)

    Le Roux, WH

    2010-06-01

    Full Text Available Augmented reality is not completely new technology, but rather an interesting combination of existing technologies, facilitated by the rapid progress made on ultra-portable devices such as smart cellular telephones. It has the potential to enhance...

  7. Single implants in the aesthetic region preceded by local ridge augmentation; a 10-year randomized controlled trial

    NARCIS (Netherlands)

    Meijndert, Caroliene M.; Raghoebar, Gerry M.; Meijndert, Leo; Stellingsma, Kees; Vissink, Arjan; Meijer, Henny J.A.

    OBJECTIVES: The aim of this randomized controlled trial was to assess the 10-year effects of three different augmentation techniques (augmentation with chin bone, augmentation with chin bone plus a membrane and augmentation with a bone substitute plus a membrane) for implant-supported restorations

  8. The use of augmented reality in command and control situation ...

    African Journals Online (AJOL)

    Augmented reality is not completely new technology, but rather an interesting combination of existing technologies, facilitated by the rapid progress made on ultra-portable devices such as smart cellular telephones. It has the potential to enhance the situation awareness of military operators. This study identifies possible ...

  9. The Roles of Parasitoid Foraging for Hosts, Food and Mates in the Augmentative Control of Tephritidae

    Directory of Open Access Journals (Sweden)

    Martin Aluja

    2012-07-01

    Full Text Available Ultimately, the success of augmentative fruit fly biological control depends upon the survival, dispersal, attack rate and multi-generational persistence of mass-reared parasitoids in the field. Foraging for hosts, food and mates is fundamental to the above and, at an operational level, the choice of the parasitoid best suited to control a particular tephritid in a certain environment, release rate estimates and subsequent monitoring of effectiveness. In the following we review landscape-level and microhabitat foraging preferences, host/fruit ranges, orientation through environmental cues, host vulnerabilities/ovipositor structures, and inter and intraspecific competition. We also consider tephritid parasitoid mating systems and sexual signals, and suggest the directions of future research.

  10. A piloted simulator investigation of side-stick controller/stability and control augmentation system requirements for helicopter visual flight tasks

    Science.gov (United States)

    Landis, K. H.; Dunford, P. J.; Aiken, E. W.; Hilbert, K. B.

    1984-01-01

    A piloted simulator experiment was conducted to assess the effects of side-stick controller characteristics and level of stability and control augmentation on handling qualities for several low-altitude control tasks. Visual flight tasks were simulated using four-window computer-generated imagery depicting either a nap-of-the-earth course or a runway with obstacles positioned to provide a slalom course. Both low speed and forward flight control laws were implemented, and a method for automatically switching control modes was developed. Variations in force-deflection characteristics and the number of axes controlled through an integrated side-stick were investigated. With high levels of stability and control augmentation, a four-axis controller with small-deflection in all four axes achieved satisfactory handling qualities for low-speed tasks.

  11. Power generation, operation and control

    CERN Document Server

    Wood, Allen J; Sheblé, Gerald B

    2013-01-01

    Since publication of the second edition, there have been extensive changes in the algorithms, methods, and assumptions in energy management systems that analyze and control power generation. This edition is updated to acquaint electrical engineering students and professionals with current power generation systems. Algorithms and methods for solving integrated economic, network, and generating system analysis are provided. Also included are the state-of-the-art topics undergoing evolutionary change, including market simulation, multiple market analysis, multiple interchange contract analysis, c

  12. Performance augmentation with vortex generators: Design and testing for stall-regulated AWT-26 turbine

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D.A. [Advanced Wind Turbines Inc., Seattle, WA (United States)

    1996-12-31

    A study investigated the use of vortex generators (VGs) for performance augmentation of the stall-regulated AWT-26 wind turbine. Based on wind-tunnel results and analysis, a VG array was designed for and tested on the AWT-26 prototype, designated Pt. Performance and loads data were measured for P1, both with and without VGs installed. The turbine performance with VGs met most of the design requirements; power output was increased at moderate wind speeds with a minimal effect on peak power. However, VG drag penalties caused a loss in power output for low wind speeds, such that performance with VGs resulted in a net decrease in AEP for wind speed sites up to 8.5 m/s. 8 refs., 8 figs., 3 tabs.

  13. Control Point Generated PLS - polygons

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Control Point Generated PLS layer contains line and polygon features to the 1/4 of 1/4 PLS section (approximately 40 acres) and government lot level. The layer...

  14. Control Point Generated PLS - lines

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Control Point Generated PLS layer contains line and polygon features to the 1/4 of 1/4 PLS section (approximately 40 acres) and government lot level. The layer...

  15. Spinal Cord Stimulation and Augmentative Control Strategies for Leg Movement after Spinal Paralysis in Humans.

    Science.gov (United States)

    Minassian, Karen; Hofstoetter, Ursula S

    2016-04-01

    Severe spinal cord injury is a devastating condition, tearing apart long white matter tracts and causing paralysis and disability of body functions below the lesion. But caudal to most injuries, the majority of neurons forming the distributed propriospinal system, the localized gray matter spinal interneuronal circuitry, and spinal motoneuron populations are spared. Epidural spinal cord stimulation can gain access to this neural circuitry. This review focuses on the capability of the human lumbar spinal cord to generate stereotyped motor output underlying standing and stepping, as well as full weight-bearing standing and rhythmic muscle activation during assisted treadmill stepping in paralyzed individuals in response to spinal cord stimulation. By enhancing the excitability state of the spinal circuitry, the stimulation can have an enabling effect upon otherwise "silent" translesional volitional motor control. Strategies for achieving functional movement in patients with severe injuries based on minimal translesional intentional control, task-specific proprioceptive feedback, and next-generation spinal cord stimulation systems will be reviewed. The role of spinal cord stimulation can go well beyond the immediate generation of motor output. With recently developed training paradigms, it can become a major rehabilitation approach in spinal cord injury for augmenting and steering trans- and sublesional plasticity for lasting therapeutic benefits. © 2016 John Wiley & Sons Ltd.

  16. Power generation, operation, and control

    CERN Document Server

    Wood, Allen J

    2012-01-01

    A comprehensive text on the operation and control of power generation and transmission systems In the ten years since Allen J. Wood and Bruce F. Wollenberg presented their comprehensive introduction to the engineering and economic factors involved in operating and controlling power generation systems in electric utilities, the electric power industry has undergone unprecedented change. Deregulation, open access to transmission systems, and the birth of independent power producers have altered the structure of the industry, while technological advances have created a host of new opportunities

  17. Analytical design of a high performance stability and control augmentation system for a hingeless rotor helicopter

    Science.gov (United States)

    Miyajima, K.

    1978-01-01

    A stability and control augmentation system (SCAS) was designed based on a set of comprehensive performance criteria. Linear optimal control theory was applied to determine appropriate feedback gains for the stability augmentation system (SAS). The helicopter was represented by six-degree-of-freedom rigid body equations of motion and constant factors were used as weightings for state and control variables. The ratio of these factors was employed as a parameter for SAS analysis and values of the feedback gains were selected on this basis to satisfy three of the performance criteria for full and partial state feedback systems. A least squares design method was then applied to determine control augmentation system (CAS) cross feed gains to satisfy the remaining seven performance criteria. The SCAS gains were then evaluated by nine degree-of-freedom equations which include flapping motion and conclusions drawn concerning the necessity of including the pitch/regressing and roll/regressing modes in SCAS analyses.

  18. Flight Test of Composite Model Reference Adaptive Control (CMRAC) Augmentation Using NASA AirSTAR Infrastructure

    Science.gov (United States)

    Gregory, Irene M.; Gadient, ROss; Lavretsky, Eugene

    2011-01-01

    This paper presents flight test results of a robust linear baseline controller with and without composite adaptive control augmentation. The flight testing was conducted using the NASA Generic Transport Model as part of the Airborne Subscale Transport Aircraft Research system at NASA Langley Research Center.

  19. A Primal-Dual Augmented Lagrangian Method for Optimal Control of ...

    African Journals Online (AJOL)

    Moreover, the formulation of a penalized matrix in the primal-dual variables with mesh-refinement strategy guarantees the reliability of the algorithm. Numerical experiments verify the efficiency of the proposed method. Keywords: Optimal control,primal-dual methods, augmented Lagrangian methods, conjugate gradient ...

  20. How to reduce workload--augmented reality to ease the work of air traffic controllers.

    Science.gov (United States)

    Hofmann, Thomas; König, Christina; Bruder, Ralph; Bergner, Jörg

    2012-01-01

    In the future the air traffic will rise--the workload of the controllers will do the same. In the BMWi research project, one of the tasks is, how to ensure safe air traffic, and a reasonable workload for the air traffic controllers. In this project it was the goal to find ways how to reduce the workload (and stress) for the controllers to allow safe air traffic, esp. at huge hub-airports by implementing augmented reality visualization and interaction.

  1. Stability Assessment and Tuning of an Adaptively Augmented Classical Controller for Launch Vehicle Flight Control

    Science.gov (United States)

    VanZwieten, Tannen; Zhu, J. Jim; Adami, Tony; Berry, Kyle; Grammar, Alex; Orr, Jeb S.; Best, Eric A.

    2014-01-01

    Recently, a robust and practical adaptive control scheme for launch vehicles [ [1] has been introduced. It augments a classical controller with a real-time loop-gain adaptation, and it is therefore called Adaptive Augmentation Control (AAC). The loop-gain will be increased from the nominal design when the tracking error between the (filtered) output and the (filtered) command trajectory is large; whereas it will be decreased when excitation of flex or sloshing modes are detected. There is a need to determine the range and rate of the loop-gain adaptation in order to retain (exponential) stability, which is critical in vehicle operation, and to develop some theoretically based heuristic tuning methods for the adaptive law gain parameters. The classical launch vehicle flight controller design technics are based on gain-scheduling, whereby the launch vehicle dynamics model is linearized at selected operating points along the nominal tracking command trajectory, and Linear Time-Invariant (LTI) controller design techniques are employed to ensure asymptotic stability of the tracking error dynamics, typically by meeting some prescribed Gain Margin (GM) and Phase Margin (PM) specifications. The controller gains at the design points are then scheduled, tuned and sometimes interpolated to achieve good performance and stability robustness under external disturbances (e.g. winds) and structural perturbations (e.g. vehicle modeling errors). While the GM does give a bound for loop-gain variation without losing stability, it is for constant dispersions of the loop-gain because the GM is based on frequency-domain analysis, which is applicable only for LTI systems. The real-time adaptive loop-gain variation of the AAC effectively renders the closed-loop system a time-varying system, for which it is well-known that the LTI system stability criterion is neither necessary nor sufficient when applying to a Linear Time-Varying (LTV) system in a frozen-time fashion. Therefore, a

  2. Sinus floor bone failures in maxillary sinus floor augmentation: a case-control study.

    Science.gov (United States)

    Cortes, Arthur Rodriguez Gonzalez; Pinheiro, Lucas Rodrigues; Cavalcanti, Marcelo Gusmão Paraíso; Arita, Emiko Saito; Tamimi, Faleh

    2015-04-01

    Extreme bone resorption in posterior maxilla may lead to absence of part of the sinus floor. This phenomenon has been termed sinus floor bone failure, and may compromise sinus floor augmentation. The present article aims to evaluate risk factors related to sinus floor bone failures and to evaluate the influence of these failures in sinus floor augmentation outcomes in patients with severely atrophic posterior maxilla. In this case-control study, patients were selected among those referred for sinus floor augmentation. Only patients presenting a ridge bone height of less than 3 mm were included. Cases were defined as presenting sinus floor bone failure, whereas controls did not present any interruption in the sinus floor bone. Information collected included clinical dental records and computed tomographic assessment of sinus width, septa, and schneiderian membrane. Risk estimates for sinus floor bone failures were calculated as adjusted odds ratios (AORs) with 95% confidence intervals (CIs) using conditional logistic regression analyses. A p value under 0.05 was considered statistically significant. In addition, sinus floor augmentation outcomes of both groups were also assessed. In all, 23 cases and 58 controls were included in the study. Sinus floor bone failures were significantly associated with the number of missing posterior teeth (AOR 3.67; 95% CI 0.86 to 15.63; p = .046) and a history of periodontitis (AOR 6.39; 95% CI 1.86 to 21.95; p = .002). Of the total, 15 cases and 27 controls underwent sinus floor augmentation. Schneiderian membrane perforation occurred during the surgery of two cases and of one control. No implants were lost during a mean postsurgical follow-up of 20 months. The number of missing posterior teeth and a history of periodontitis may be considered as risk factors for sinus floor bone failures. © 2013 Wiley Periodicals, Inc.

  3. Using an Augmented Wobble Board as a Game Controller

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania

    2017-01-01

    and evaluation of three prototypes intended to provide individuals in need of ankle rehabilitation with the necessary motivation. The prototypes leverage video games potential as a source of intrinsic motivation by allowing individuals to control a game by means of a wobble board—an instrument used for ankle...... with actuators and thereby provide vibrotactile feedback to the user while playing. The results of the performed evaluation indicated that the additional feedback need not improve performance in relation to the particular game being played. Moreover, the results suggest that one should be mindful when to add...

  4. Augmenting Plant Immune Responses and Biological Control by Microbial Determinants

    Directory of Open Access Journals (Sweden)

    Sang Moo Lee

    2015-09-01

    Full Text Available Plant have developed sophisticated defence mechanisms against microbial pathogens. The recent accumulated information allow us to understand the nature of plant immune responses followed by recognition of microbial factors/determinants through cutting-edge genomics and multi-omics techniques. However, the practical approaches to sustain plant health using enhancement of plant immunity is yet to be fully appreciated. Here, we overviewed the general concept and representative examples on the plant immunity. The fungal, bacterial, and viral determinants that was previously reported as the triggers of plant immune responses are introduced and described as the potential protocol of biological control. Specifically, the role of chitin, glucan, lipopolysaccharides/extracellular polysaccharides, microbe/pathogen-associated molecular pattern, antibiotics, mimic-phytohormones, N-acyl homoserine lactone, harpin, vitamins, and volatile organic compounds are considered. We hope that this review stimulates scientific community and farmers to broaden their knowledge on the microbial determinant-based biological control and to apply the technology on the integrated pest management program.

  5. Using an Augmented Wobble Board as a Game Controller

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania

    2017-01-01

    and evaluation of three prototypes intended to provide individuals in need of ankle rehabilitation with the necessary motivation. The prototypes leverage video games potential as a source of intrinsic motivation by allowing individuals to control a game by means of a wobble board—an instrument used for ankle...... vibrotactile feedback during wobble board games since the feedback may distract the user, but also has the potential to make the experience more involving......., and a user study suggested that participants generally found the act of playing intrinsically motivating. In a second study we compared a the wobble board interface with to commercially available input devices (the Wii balance board, and keyboard and mouse). The results provided insights about...

  6. Simulator investigations of side-stick controller/stability and control augmentation systems for night nap-of-earth flight

    Science.gov (United States)

    Landis, K. H.; Aiken, E. W.

    1984-01-01

    Several night nap-of-the-earth mission tasks were evaluated using a helmet-mounted display which provided a limited field-of-view image with superimposed flight control symbology. A wide range of stability and control augmentation designs was investigated. Variations in controller force-deflection characteristics and the number of axes controlled through an integrated side-stick controller were studied. In general, a small displacement controller is preferred over a stiffstick controller particularly for maneuvering flight. Higher levels of stability augmentation were required for IMC tasks to provide handling qualities comparable to those achieved for the same tasks conducted under simulated visual flight conditions. Previously announced in STAR as N82-23216

  7. Design of a Stability Augmentation System for an Unmanned Helicopter Based on Adaptive Control Techniques

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2015-09-01

    Full Text Available The task of control of unmanned helicopters is rather complicated in the presence of parametric uncertainties and measurement noises. This paper presents an adaptive model feedback control algorithm for an unmanned helicopter stability augmentation system. The proposed algorithm can achieve a guaranteed model reference tracking performance and speed up the convergence rates of adjustable parameters, even when the plant parameters vary rapidly. Moreover, the model feedback strategy in the algorithm further contributes to the improvement in the control quality of the stability augmentation system in the case of low signal to noise ratios, mainly because the model feedback path is noise free. The effectiveness and superiority of the proposed algorithm are demonstrated through a series of tests.

  8. Artificial Bee Colony Algorithm for Transient Performance Augmentation of Grid Connected Distributed Generation

    Science.gov (United States)

    Chatterjee, A.; Ghoshal, S. P.; Mukherjee, V.

    In this paper, a conventional thermal power system equipped with automatic voltage regulator, IEEE type dual input power system stabilizer (PSS) PSS3B and integral controlled automatic generation control loop is considered. A distributed generation (DG) system consisting of aqua electrolyzer, photovoltaic cells, diesel engine generator, and some other energy storage devices like flywheel energy storage system and battery energy storage system is modeled. This hybrid distributed system is connected to the grid. While integrating this DG with the onventional thermal power system, improved transient performance is noticed. Further improvement in the transient performance of this grid connected DG is observed with the usage of superconducting magnetic energy storage device. The different tunable parameters of the proposed hybrid power system model are optimized by artificial bee colony (ABC) algorithm. The optimal solutions offered by the ABC algorithm are compared with those offered by genetic algorithm (GA). It is also revealed that the optimizing performance of the ABC is better than the GA for this specific application.

  9. The use of active controls to augment rotor/fuselage stability

    Science.gov (United States)

    Straub, F. K.; Warmbrodt, W.

    1985-01-01

    The use of active blade pitch control to increase helicopter rotor/body damping is studied. Control is introduced through a conventional nonrotating swashplate. State variable feedback of rotor and body states is used. Feedback parameters include cyclic rotor flap and lead-lag states, and body pitch and roll rotations. The use of position, rate, and acceleration feedback is studied for the various state variables. In particular, the influence of the closed loop feedback gain and phase on system stability is investigated. For the rotor/body configuration analyzed, rotor cyclic inplane motion and body roll-rate and roll-acceleration feedback can considerably augment system damping levels and eliminate ground resonance instabilities. Scheduling of the feedback state, phase, and gain with rotor rotation speed can be used to maximize the damping augmentation. This increase in lead-lag damping can be accomplished without altering any of the system modal frequencies. Investigating various rotor design parameters (effective hinge offset, blade precone, blade flap stiffness) indicates that active control for augmenting rotor/body damping will be particularly powerful for hingeless and bearingless rotor hubs.

  10. Grafting Acoustic Instruments and Signal Processing: Creative Control and Augmented Expressivity

    DEFF Research Database (Denmark)

    Overholt, Daniel; Freed, Adrian

    In this study, work is presented on a hybrid acoustic / electric violin. The instrument has embedded processing that provides real-time simulation of acoustic body models using DSP techniques able to gradually transform a given body model into another, including extrapolations beyond the models...... to explore interesting new timbres. Models can include everything from various violin bodies to guitars, sitars with their sympathetic strings, and even physically impossible acoustic bodies. The development also presents several practical approaches to sensor augmentation and gestural playing techniques...... that can be applied to bowed-string and other acoustic instruments, in order to provide immediate creative control over the possibilities offered by DSP. The study has focused on augmenting the expressivity of the violin towards finding novel timbral possibilities, rather than a goal of simulating prior...

  11. Sensor-augmented pump therapy lowers HbA(1c) in suboptimally controlled Type 1 diabetes; a randomized controlled trial

    DEFF Research Database (Denmark)

    Hermanides, J; Nørgaard, K; Bruttomesso, D

    2011-01-01

    To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes.......To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes....

  12. Initial virtual flight test for a dynamically similar aircraft model with control augmentation system

    Directory of Open Access Journals (Sweden)

    Linliang Guo

    2017-04-01

    Full Text Available To satisfy the validation requirements of flight control law for advanced aircraft, a wind tunnel based virtual flight testing has been implemented in a low speed wind tunnel. A 3-degree-of-freedom gimbal, ventrally installed in the model, was used in conjunction with an actively controlled dynamically similar model of aircraft, which was equipped with the inertial measurement unit, attitude and heading reference system, embedded computer and servo-actuators. The model, which could be rotated around its center of gravity freely by the aerodynamic moments, together with the flow field, operator and real time control system made up the closed-loop testing circuit. The model is statically unstable in longitudinal direction, and it can fly stably in wind tunnel with the function of control augmentation of the flight control laws. The experimental results indicate that the model responds well to the operator’s instructions. The response of the model in the tests shows reasonable agreement with the simulation results. The difference of response of angle of attack is less than 0.5°. The effect of stability augmentation and attitude control law was validated in the test, meanwhile the feasibility of virtual flight test technique treated as preliminary evaluation tool for advanced flight vehicle configuration research was also verified.

  13. Launch vehicle flight control augmentation using smart materials and advanced composites (CDDF Project 93-05)

    Science.gov (United States)

    Barret, C.

    1995-01-01

    The Marshall Space Flight Center has a rich heritage of launch vehicles that have used aerodynamic surfaces for flight stability such as the Saturn vehicles and flight control such as on the Redstone. Recently, due to aft center-of-gravity locations on launch vehicles currently being studied, the need has arisen for the vehicle control augmentation that is provided by these flight controls. Aerodynamic flight control can also reduce engine gimbaling requirements, provide actuator failure protection, enhance crew safety, and increase vehicle reliability, and payload capability. In the Saturn era, NASA went to the Moon with 300 sq ft of aerodynamic surfaces on the Saturn V. Since those days, the wealth of smart materials and advanced composites that have been developed allow for the design of very lightweight, strong, and innovative launch vehicle flight control surfaces. This paper presents an overview of the advanced composites and smart materials that are directly applicable to launch vehicle control surfaces.

  14. Launch vehicle flight control augmentation using smart materials and advanced composites (CDDF Project 93-05)

    Science.gov (United States)

    Barret, C.

    1995-02-01

    The Marshall Space Flight Center has a rich heritage of launch vehicles that have used aerodynamic surfaces for flight stability such as the Saturn vehicles and flight control such as on the Redstone. Recently, due to aft center-of-gravity locations on launch vehicles currently being studied, the need has arisen for the vehicle control augmentation that is provided by these flight controls. Aerodynamic flight control can also reduce engine gimbaling requirements, provide actuator failure protection, enhance crew safety, and increase vehicle reliability, and payload capability. In the Saturn era, NASA went to the Moon with 300 sq ft of aerodynamic surfaces on the Saturn V. Since those days, the wealth of smart materials and advanced composites that have been developed allow for the design of very lightweight, strong, and innovative launch vehicle flight control surfaces. This paper presents an overview of the advanced composites and smart materials that are directly applicable to launch vehicle control surfaces.

  15. Early versus delayed oxytocin augmentation in nulliparous women with prolonged labour--a randomised controlled trial.

    Science.gov (United States)

    Dencker, A; Berg, M; Bergqvist, L; Ladfors, L; Thorsén, L S; Lilja, H

    2009-03-01

    To study the effects of early versus delayed oxytocin augmentation on the obstetrical and neonatal outcome in nulliparous women with spontaneous but prolonged labour. Randomised controlled study. Two delivery units in Sweden. Healthy nulliparous women with normal pregnancies, spontaneous onset of active labour, a cervical dilatation of 4-9 cm and no progress in cervical dilatation for 2 hours and for an additional hour if amniotomy was performed due to slow progress. Women (n = 630) were randomly allocated either to labour augmentation by oxytocin infusion (early oxytocin group) or to postponement of oxytocin augmentation for another 3 hours (expectant group). Mode of delivery (spontaneous vaginal or instrumental vaginal delivery or caesarean section) and time from randomisation to delivery. The caesarean section rate was 29 of 314 (9%) in the early oxytocin group and 34 of 316 (11%) in the expectant group (OR 0.8, 95% CI 0.5-1.4), and instrumental vaginal delivery 54 of 314 (17%) in the early oxytocin versus 38 of 316 (12%) in the expectant group (OR 1.5, 95% CI 0.97-2.4). Early initiation of oxytocin resulted in a mean decrease of 85 minutes in the randomisation to delivery interval. Early administration of oxytocin did not change the rate of caesarean section or instrumental vaginal delivery but shortened labour duration significantly in women with a 2-hour arrest in cervical dilatation. No other clear benefits or harms were seen between early and delayed administration of oxytocin.

  16. A leader-followers model of transmission augmentation for considering strategic behaviours of generating companies in energy markets

    Energy Technology Data Exchange (ETDEWEB)

    Hesamzadeh, M.R.; Hosseinzadeh, N. [Swinburne University of Technology, Melbourne (Australia); Wolfs, P.J. [Curtin University of Technology, Perth (Australia)

    2010-06-15

    This paper suggests an integrated mathematical framework developed based on the leader-followers game for augmentation of transmission networks. Transmission Network Service Provider moves first and designs the horizon year transmission system. Generating Companies compete for having the highest share from the energy market and they find their equilibrium point using the Nash equilibrium concept. Finally, Market Management Company receives the planning schedule of transmission system and the energy offer prices and clears the market. In addition to the exact mathematical modelling of the interested players of transmission planning problem, the methodology can design the future transmission system not only for improving the system social welfare but also for encouraging competition among horizon year generating companies. (author)

  17. Cooperative synthesis of control and display augmentation for a STOL aircraft in the approach and landing task

    Science.gov (United States)

    Garg, Sanjay; Schmidt, David K.

    1988-01-01

    Application of the Cooperative methodology to synthesize control/display augmentation systems for the piloted longitudinal landing task with a modern, statically-unstable, fighter aircraft is considered. Starting with a control augmentation law which yields augmented vehicle dynamics that meet Level I handling qualities specifications, the effect of time-delay in the Head-up-display is studied using model-based criterion. This evaluation showed that even with 'good' conventional dynamics, a realistic value of display time-delay will cause significant deterioration in pilot workload and piloted-system performance. Application of the Cooperative methodology to control augmentation alone resulted in augmented vehicle dynamics which provide direct control of the flight path from the pilot stick. Analytical evaluation of these dynamics indicates that such dynamics might lead to improved pilot ratings over conventional dynamics, especially in the presence of time-delays in the system. Also, application of the methodology to simultaneous synthesis of control augmentation and flight director laws revealed that it might be advantageous to consider the control/display trade-off in the early design stages.

  18. Computer-Controlled Force Generator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TDA Research, Inc proposes to develop a compact, low power, high life-cycle computer controlled Programmable Force Generator (PFG) that can generate any force...

  19. Control of uncertain systems by feedback linearization with neural networks augmentation. Part II. Controller validation by numerical simulation

    Directory of Open Access Journals (Sweden)

    Adrian TOADER

    2010-09-01

    Full Text Available The paper was conceived in two parts. Part I, previously published in this journal, highlighted the main steps of adaptive output feedback control for non-affine uncertain systems, having a known relative degree. The main paradigm of this approach was the feedback linearization (dynamic inversion with neural network augmentation. Meanwhile, based on new contributions of the authors, a new paradigm, that of robust servomechanism problem solution, has been added to the controller architecture. The current Part II of the paper presents the validation of the controller hereby obtained by using the longitudinal channel of a hovering VTOL-type aircraft as mathematical model.

  20. An Optimal Augmented Monotonic Tracking Controller for Aircraft Engines with Output Constraints

    Directory of Open Access Journals (Sweden)

    Jiakun Qin

    2017-01-01

    Full Text Available This paper proposes a novel min-max control scheme for aircraft engines, with the aim of transferring a set of regulated outputs between two set-points, while ensuring a set of auxiliary outputs remain within prescribed constraints. In view of this, an optimal augmented monotonic tracking controller (OAMTC is proposed, by considering a linear plant with input integration, to enhance the ability of the control system to reject uncertainty in system parameters and ensure no crossing limits. The key idea is to use the eigenvalue and eigenvector placement method and genetic algorithms to shape the output responses. The approach is validated by numerical simulation. The results show that the designed OAMTC controller can achieve a satisfactory dynamic and steady performance and keep the auxiliary outputs within constraints in the transient regime.

  1. A flight investigation of static stability, control augmentation, and flight director influences on helicopter IFR handling qualities

    Science.gov (United States)

    Lebacqz, J. V.; Weber, J. M.; Corliss, L. D.

    1981-01-01

    A flight experiment was conducted using the NASA-Army V/STOLAND UH-1H variable-stability helicopter to investigate the influence of several longitudinal-static-stability, control-augmentation, and flight-director parameters on helicopter flying qualities during terminal area operations in instrument conditions. This experiment, which was part of a joint NASA/FAA program pertaining to helicopter IFR airworthiness, was designed to corroborate and extend previous ground simulation results obtained in this program. Variations examined included stable and neutral longitudinal control position gradients, rate-damping and attitude-command augmentation, and raw data versus flight-director displays. Pilot rating results agreed excellently with the ground simulation data, indicating an adequate instrument capability with rate-damping augmentation and neutral statics and the need for pitch-roll attitude augmentation to achieve a satisfactory system.

  2. A Systematic Methodology for Actuator Augmentation in the Supervisory Control of Discrete Event Systems

    Directory of Open Access Journals (Sweden)

    Vigyan Chandra

    2006-10-01

    Full Text Available Supervisory control theory of discrete event systems in the Ramade-Wonham paradigm addresses the problem of restricting the system evolution so that it conforms to certain predefined behavior commonly referred to as specifications. This theory states that a sequence of events that cause the plant to violate the specifications is suitably pruned or eliminated. However, in doing so, event traces, partial prefixes of which that actually meet control specification are eliminated as well. This happens for instance whenever a chain of uncontrollable event extensions render the plant behavior trajectory irrevocably outside the outlined specifications. Such partial conformance can be ensured if the capability of the system is augmented by additional actuators so that in the augmented plant there is a greater degree of control over uncontrollable events. It does not follow trivially where such actuators are to be placed. We propose an algorithm that enables us to identify states of the automaton where the new actuators need to be inserted, thus enlarging the scope of its applicability to system identification purposes as well.

  3. Virtual Planning, Control, and Machining for a Modular-Based Automated Factory Operation in an Augmented Reality Environment

    Science.gov (United States)

    Pai, Yun Suen; Yap, Hwa Jen; Md Dawal, Siti Zawiah; Ramesh, S.; Phoon, Sin Ye

    2016-06-01

    This study presents a modular-based implementation of augmented reality to provide an immersive experience in learning or teaching the planning phase, control system, and machining parameters of a fully automated work cell. The architecture of the system consists of three code modules that can operate independently or combined to create a complete system that is able to guide engineers from the layout planning phase to the prototyping of the final product. The layout planning module determines the best possible arrangement in a layout for the placement of various machines, in this case a conveyor belt for transportation, a robot arm for pick-and-place operations, and a computer numerical control milling machine to generate the final prototype. The robotic arm module simulates the pick-and-place operation offline from the conveyor belt to a computer numerical control (CNC) machine utilising collision detection and inverse kinematics. Finally, the CNC module performs virtual machining based on the Uniform Space Decomposition method and axis aligned bounding box collision detection. The conducted case study revealed that given the situation, a semi-circle shaped arrangement is desirable, whereas the pick-and-place system and the final generated G-code produced the highest deviation of 3.83 mm and 5.8 mm respectively.

  4. Virtual Planning, Control, and Machining for a Modular-Based Automated Factory Operation in an Augmented Reality Environment.

    Science.gov (United States)

    Pai, Yun Suen; Yap, Hwa Jen; Md Dawal, Siti Zawiah; Ramesh, S; Phoon, Sin Ye

    2016-06-07

    This study presents a modular-based implementation of augmented reality to provide an immersive experience in learning or teaching the planning phase, control system, and machining parameters of a fully automated work cell. The architecture of the system consists of three code modules that can operate independently or combined to create a complete system that is able to guide engineers from the layout planning phase to the prototyping of the final product. The layout planning module determines the best possible arrangement in a layout for the placement of various machines, in this case a conveyor belt for transportation, a robot arm for pick-and-place operations, and a computer numerical control milling machine to generate the final prototype. The robotic arm module simulates the pick-and-place operation offline from the conveyor belt to a computer numerical control (CNC) machine utilising collision detection and inverse kinematics. Finally, the CNC module performs virtual machining based on the Uniform Space Decomposition method and axis aligned bounding box collision detection. The conducted case study revealed that given the situation, a semi-circle shaped arrangement is desirable, whereas the pick-and-place system and the final generated G-code produced the highest deviation of 3.83 mm and 5.8 mm respectively.

  5. Controls Middleware the New Generation

    CERN Document Server

    Kostro, K; Calderini, F; Chevrier, F L; Jensen, S; Swoboda, R; Trofimov, N N

    2002-01-01

    A new Controls Middleware (CMW) for the "LHC era" has been recently designed and implemented to serve the CERN accelerator sector. It is object-oriented and supports two conceptual models: The Device model traditionally used in accelerator controls and the Topic model, which is widely used in the commercial world. Unlikely previous middleware solutions, developed in the 80's, this middleware is completely build upon commercial standards: CORBA for synchronous calls, JMS (Java Message Service) for message passing and OPC (OLE for Process Control) for integration of industrial equipment. The subscription paradigm is supported in both Device and Topic models. This paper presents the system architecture and an overview of the user facilities and API's. The experience with CMW, the issues of integration of CORBA, JMS and OPC and system administration are addressed as well.

  6. Augmented Nonlinear Controller for Maximum Power-Point Tracking with Artificial Neural Network in Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Suliang Ma

    2016-11-01

    Full Text Available Photovoltaic (PV systems have non-linear characteristics that generate maximum power at one particular operating point. Environmental factors such as irradiance and temperature variations greatly affect the maximum power point (MPP. Diverse offline and online techniques have been introduced for tracking the MPP. Here, to track the MPP, an augmented-state feedback linearized (AFL non-linear controller combined with an artificial neural network (ANN is proposed. This approach linearizes the non-linear characteristics in PV systems and DC/DC converters, for tracking and optimizing the PV system operation. It also reduces the dependency of the designed controller on linearized models, to provide global stability. A complete model of the PV system is simulated. The existing maximum power-point tracking (MPPT and DC/DC boost-converter controller techniques are compared with the proposed ANN method. Two case studies, which simulate realistic circumstances, are presented to demonstrate the effectiveness and superiority of the proposed method. The AFL with ANN controller can provide good dynamic operation, faster convergence speed, and fewer operating-point oscillations around the MPP. It also tracks the global maxima under different conditions, especially irradiance-mutating situations, more effectively than the conventional methods. Detailed mathematical models and a control approach for a three-phase grid-connected intelligent hybrid system are proposed using MATLAB/Simulink.

  7. Numerical Investigation of Heat Transfer Augmentation through Geometrical Optimization of Vortex Generators

    DEFF Research Database (Denmark)

    Gorji, Mofid; Mirgolbabaei, Hessam; Barari, Amin

    2010-01-01

    In this paper a two-dimensional numerical simulation of a steady incompressible and turbulent model has been carried out to study the effects of vortex generators in a compact heat exchanger in a curvilinear coordinate system. The mesh which is applied in this study is boundary fitted and has bee...

  8. DESIGN AND DEVELOPMENT OF AUGMENTATIVE AND ALTERNATIVE DIGITAL HOME CONTROL INTERFACE

    Directory of Open Access Journals (Sweden)

    Matteo Pastorino

    2013-05-01

    Full Text Available An inquiry of the National Statistics Institute of Spain shows that 74% of the Spanish population with disabilities suffers some kind of limitation performing Daily Basic Activities, while 1.39 million cannot perform them at all without the assistance of specialized personnel. Digital Home Systems could mitigate disabled people’s difficulties to carry out those activities, giving the opportunity to manage home appliances through a single control. Digital Home Systems have to provide specific and adapted control interfaces based on Augmentative and Alternative Communication languages in order to be an efficient solution to the problem and to allow most vulnerable groups of people with disabilities to reach the highest level of autonomy.  This paper describes a Digital Home Interface capable of adapting layouts, styles and contents to device capability, user preferences and appliances’ features; designed with a combination of web technologies, standard languages for abstract interface definition and AAC systems.

  9. Ultrasound guided robotic biopsy using augmented reality and human-robot cooperative control.

    Science.gov (United States)

    Freschi, C; Troia, E; Ferrari, V; Megali, G; Pietrabissa, A; Mosca, F

    2009-01-01

    Ultrasound-guided biopsy is a proficient mininvasive approach for tumors staging but requires very long training and particular manual and 3D space perception abilities of the physician, for the planning of the needle trajectory and the execution of the procedure. In order to simplify this difficult task, we have developed an integrated system that provides the clinician two types of assistance: an augmented reality visualization allows accurate and easy planning of needle trajectory and target reaching verification; a robot arm with a six-degree-of-freedom force sensor allows the precise positioning of the needle holder and allows the clinician to adjust the planned trajectory (cooperative control) to overcome needle deflection and target motion. Preliminary tests have been executed on an ultrasound phantom showing high precision of the system in static conditions and the utility and usability of the cooperative control in simulated no-rigid conditions.

  10. Treadmill training as an augmentation treatment for Alzheimer?s disease: a pilot randomized controlled study

    Directory of Open Access Journals (Sweden)

    Cynthia Arcoverde

    2014-03-01

    Full Text Available Objective To assess the effect of aerobic exercise on the cognition and functional capacity in Alzheimer’s disease (AD patients. Method Elderly (n=20 with mild dementia (NINCDS-ADRDA/CDR1 were randomly assigned to an exercise group (EG on a treadmill (30 minutes, twice a week and moderate intensity of 60% VO2max and control group (GC 10 patients. The primary outcome measure was the cognitive function using Cambridge Cognitive Examination (CAMCOG. Specifics instruments were also applied to evaluate executive function, memory, attention and concentration, cognitive flexibility, inhibitory control and functional capacity. Results After 16 weeks, the EG showed improvement in cognition CAMCOG whereas the CG declined. Compared to the CG, the EG presented significant improvement on the functional capacity. The analysis of the effect size has shown a favorable response to the physical exercise in all dependent variables. Conclusion Walking on treadmill may be recommended as an augmentation treatment for patients with AD.

  11. Stereovision and augmented reality for closed-loop control of grasping in hand prostheses.

    Science.gov (United States)

    Markovic, Marko; Dosen, Strahinja; Cipriani, Christian; Popovic, Dejan; Farina, Dario

    2014-08-01

    Technologically advanced assistive devices are nowadays available to restore grasping, but effective and effortless control integrating both feed-forward (commands) and feedback (sensory information) is still missing. The goal of this work was to develop a user friendly interface for the semi-automatic and closed-loop control of grasping and to test its feasibility. We developed a controller based on stereovision to automatically select grasp type and size and augmented reality (AR) to provide artificial proprioceptive feedback. The system was experimentally tested in healthy subjects using a dexterous hand prosthesis to grasp a set of daily objects. The subjects wore AR glasses with an integrated stereo-camera pair, and triggered the system via a simple myoelectric interface. The results demonstrated that the subjects got easily acquainted with the semi-autonomous control. The stereovision grasp decoder successfully estimated the grasp type and size in realistic, cluttered environments. When allowed (forced) to correct the automatic system decisions, the subjects successfully utilized the AR feedback and achieved close to ideal system performance. The new method implements a high level, low effort control of complex functions in addition to the low level closed-loop control. The latter is achieved by providing rich visual feedback, which is integrated into the real life environment. The proposed system is an effective interface applicable with small alterations for many advanced prosthetic and orthotic/therapeutic rehabilitation devices.

  12. An assessment of various side-stick controller/stability and control augmentation systems for night nap-of-Earth flight using piloted simulation

    Science.gov (United States)

    Landis, K. H.; Aiken, E. W.

    1982-01-01

    Several night nap-of-the-earth mission tasks were evaluated using a helmet-mounted display which provided a limited field-of-view image with superimposed flight control symbology. A wide range of stability and control augmentation designs was investigated. Variations in controller force-deflection characteristics and the number of axes controlled through an integrated side-stick controller were studied. In general, a small displacement controller is preferred over a stiffstick controller particularly for maneuvering flight. Higher levels of stability augmentation were required for IMC tasks to provide handling qualities comparable to those achieved for the same tasks conducted under simulated visual flight conditions.

  13. Text generation from Taiwanese Sign Language using a PST-based language model for augmentative communication.

    Science.gov (United States)

    Wu, Chung-Hsien; Chiu, Yu-Hsien; Guo, Chi-Shiang

    2004-12-01

    This paper proposes a novel approach to the generation of Chinese sentences from ill-formed Taiwanese Sign Language (TSL) for people with hearing impairments. First, a sign icon-based virtual keyboard is constructed to provide a visualized interface to retrieve sign icons from a sign database. A proposed language model (LM), based on a predictive sentence template (PST) tree, integrates a statistical variable n-gram LM and linguistic constraints to deal with the translation problem from ill-formed sign sequences to grammatical written sentences. The PST tree trained by a corpus collected from the deaf schools was used to model the correspondence between signed and written Chinese. In addition, a set of phrase formation rules, based on trigger pair category, was derived for sentence pattern expansion. These approaches improved the efficiency of text generation and the accuracy of word prediction and, therefore, improved the input rate. For the assessment of practical communication aids, a reading-comprehension training program with ten profoundly deaf students was undertaken in a deaf school in Tainan, Taiwan. Evaluation results show that the literacy aptitude test and subjective satisfactory level are significantly improved.

  14. Mean Field Type Control with Congestion (II): An Augmented Lagrangian Method

    Energy Technology Data Exchange (ETDEWEB)

    Achdou, Yves, E-mail: achdou@ljll.univ-paris-diderot.fr; Laurière, Mathieu [Univ. Paris Diderot, Sorbonne Paris Cité, Laboratoire Jacques-Louis Lions, UMR 7598, UPMC, CNRS (France)

    2016-12-15

    This work deals with a numerical method for solving a mean-field type control problem with congestion. It is the continuation of an article by the same authors, in which suitably defined weak solutions of the system of partial differential equations arising from the model were discussed and existence and uniqueness were proved. Here, the focus is put on numerical methods: a monotone finite difference scheme is proposed and shown to have a variational interpretation. Then an Alternating Direction Method of Multipliers for solving the variational problem is addressed. It is based on an augmented Lagrangian. Two kinds of boundary conditions are considered: periodic conditions and more realistic boundary conditions associated to state constrained problems. Various test cases and numerical results are presented.

  15. Augmented generation of protein fragments during wakefulness as the molecular cause of sleep: a hypothesis

    Science.gov (United States)

    Varshavsky, Alexander

    2012-01-01

    Despite extensive understanding of sleep regulation, the molecular-level cause and function of sleep are unknown. I suggest that they originate in individual neurons and stem from increased production of protein fragments during wakefulness. These fragments are transient parts of protein complexes in which the fragments were generated. Neuronal Ca2+ fluxes are higher during wakefulness than during sleep. Subunits of transmembrane channels and other proteins are cleaved by Ca2+-activated calpains and by other nonprocessive proteases, including caspases and secretases. In the proposed concept, termed the fragment generation (FG) hypothesis, sleep is a state during which the production of fragments is decreased (owing to lower Ca2+ transients) while fragment-destroying pathways are upregulated. These changes facilitate the elimination of fragments and the remodeling of protein complexes in which the fragments resided. The FG hypothesis posits that a proteolytic cleavage, which produces two fragments, can have both deleterious effects and fitness-increasing functions. This (previously not considered) dichotomy can explain both the conservation of cleavage sites in proteins and the evolutionary persistence of sleep, because sleep would counteract deleterious aspects of protein fragments. The FG hypothesis leads to new explanations of sleep phenomena, including a longer sleep after sleep deprivation. Studies in the 1970s showed that ethanol-induced sleep in mice can be strikingly prolonged by intracerebroventricular injections of either Ca2+ alone or Ca2+ and its ionophore (Erickson et al., Science 1978;199:1219–1221; Harris, Pharmacol Biochem Behav 1979;10:527–534; Erickson et al., Pharmacol Biochem Behav 1980;12:651–656). These results, which were never interpreted in connection to protein fragments or the function of sleep, may be accounted for by the FG hypothesis about molecular causation of sleep. PMID:22930402

  16. Adaptive Control Algorithm of the Synchronous Generator

    Directory of Open Access Journals (Sweden)

    Shevchenko Victor

    2017-01-01

    Full Text Available The article discusses the the problem of controlling a synchronous generator, namely, maintaining the stability of the control object in the conditions of occurrence of noise and disturbances in the regulatory process. The model of a synchronous generator is represented by a system of differential equations of Park-Gorev, where state variables are computed relative to synchronously rotating d, q-axis. Management of synchronous generator is proposed to organize on the basis of the position-path control using algorithms to adapt with the reference model. Basic control law directed on the stabilizing indicators the frequency generated by the current and the required power level, which is achieved by controlling the mechanical torque on the shaft of the turbine and the value of the excitation voltage of the synchronous generator. Modification of the classic adaptation algorithm using the reference model, allowing to minimize the error of the reference regulation and the model under investigation within the prescribed limits, produced by means of the introduction of additional variables controller adaptation in the model. Сarried out the mathematical modeling of control provided influence on the studied model of continuous nonlinear and unmeasured the disturbance. Simulation results confirm the high level accuracy of tracking and adaptation investigated model with respect to the reference, and the present value of the loop error depends on parameters performance of regulator.

  17. Thinking Cap Plus Thinking Zap: tDCS of Frontopolar Cortex Improves Creative Analogical Reasoning and Facilitates Conscious Augmentation of State Creativity in Verb Generation.

    Science.gov (United States)

    Green, Adam E; Spiegel, Katherine A; Giangrande, Evan J; Weinberger, Adam B; Gallagher, Natalie M; Turkeltaub, Peter E

    2017-04-01

    Recent neuroimaging evidence indicates neural mechanisms that support transient improvements in creative performance (augmented state creativity) in response to cognitive interventions (creativity cueing). Separately, neural interventions via tDCS show encouraging potential for modulating neuronal function during creative performance. If cognitive and neural interventions are separately effective, can they be combined? Does state creativity augmentation represent "real" creativity, or do interventions simply yield divergence by diminishing meaningfulness/appropriateness? Can augmenting state creativity bolster creative reasoning that supports innovation, particularly analogical reasoning? To address these questions, we combined tDCS with creativity cueing. Testing a regionally specific hypothesis from neuroimaging, high-definition tDCS-targeted frontopolar cortex activity recently shown to predict state creativity augmentation. In a novel analogy finding task, participants under tDCS formulated substantially more creative analogical connections in a large matrix search space (creativity indexed via latent semantic analysis). Critically, increased analogical creativity was not due to diminished accuracy in discerning valid analogies, indicating "real" creativity rather than inappropriate divergence. A simpler relational creativity paradigm (modified verb generation) revealed a tDCS-by-cue interaction; tDCS further enhanced creativity cue-related increases in semantic distance. Findings point to the potential of noninvasive neuromodulation to enhance creative relational cognition, including augmentation of the deliberate effort to formulate connections between distant concepts. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial.

    Science.gov (United States)

    Botella, Cristina; Pérez-Ara, M Ángeles; Bretón-López, Juana; Quero, Soledad; García-Palacios, Azucena; Baños, Rosa María

    2016-01-01

    Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31) versus an Augmented Reality system (N = 32) in a randomized controlled trial. "One-session treatment" guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants' expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.

  19. In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Cristina Botella

    Full Text Available Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31 versus an Augmented Reality system (N = 32 in a randomized controlled trial. "One-session treatment" guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants' expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.

  20. A randomized controlled study of power posing before public speaking exposure for social anxiety disorder: No evidence for augmentative effects

    NARCIS (Netherlands)

    Davis, M.L.; Papini, S.; Rosenfield, D.; Roelofs, K.; Kolb, S.; Powers, M.B.; Smits, J.A.J.

    2017-01-01

    This manuscript details a randomized controlled study designed to test the efficacy of power posing (i.e., briefly holding postures associated with dominance and power) as an augmentative strategy for exposure therapy for social anxiety disorder (SAD). Seventy-three individuals diagnosed with SAD

  1. Augmented Reality for Real-Time Detection and Interpretation of Colorimetric Signals Generated by Paper-Based Biosensors.

    Science.gov (United States)

    Russell, Steven M; Doménech-Sánchez, Antonio; de la Rica, Roberto

    2017-06-23

    Colorimetric tests are becoming increasingly popular in point-of-need analyses due to the possibility of detecting the signal with the naked eye, which eliminates the utilization of bulky and costly instruments only available in laboratories. However, colorimetric tests may be interpreted incorrectly by nonspecialists due to disparities in color perception or a lack of training. Here we solve this issue with a method that not only detects colorimetric signals but also interprets them so that the test outcome is understandable for anyone. It consists of an augmented reality (AR) app that uses a camera to detect the colored signals generated by a nanoparticle-based immunoassay, and that yields a warning symbol or message when the concentration of analyte is higher than a certain threshold. The proposed method detected the model analyte mouse IgG with a limit of detection of 0.3 μg mL -1 , which was comparable to the limit of detection afforded by classical densitometry performed with a nonportable device. When adapted to the detection of E. coli, the app always yielded a "hazard" warning symbol when the concentration of E. coli in the sample was above the infective dose (10 6 cfu mL -1 or higher). The proposed method could help nonspecialists make a decision about drinking from a potentially contaminated water source by yielding an unambiguous message that is easily understood by anyone. The widespread availability of smartphones along with the inexpensive paper test that requires no enzymes to generate the signal makes the proposed assay promising for analyses in remote locations and developing countries.

  2. Tantalum acetabular augments in one-stage exchange of infected total hip arthroplasty: a case-control study.

    Science.gov (United States)

    Klatte, Till Orla; Kendoff, Daniel; Sabihi, Reza; Kamath, Atul F; Rueger, Johannes M; Gehrke, Thorsten

    2014-07-01

    During the one-stage exchange procedure for periprosthetic joint infection (PJI) after total hip arthroplasty (THA), acetabular defects challenge reconstructive options. Porous tantalum augments are an established tool for addressing acetabular destruction in aseptic cases, but their utility in septic exchange is unknown. This retrospective case-control study presents the initial results of tantalum augmentation during one-stage exchange for PJI. Primary endpoints were rates of re-infection and short-term complications associated with this technique. Study patients had no higher risk of re-infection with equivalent durability at early follow-up with a re-infection rate in both groups of 4%. In conclusion, tantalum augments are a viable option for addressing acetabular defects in one-stage exchange for septic THA. Further study is necessary to assess long-term durability when compared to traditional techniques for acetabular reconstruction. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Intelligent control schemes applied to Automatic Generation Control

    Directory of Open Access Journals (Sweden)

    Dingguo Chen

    2016-04-01

    Full Text Available Integrating ever increasing amount of renewable generating resources to interconnected power systems has created new challenges to the safety and reliability of today‟s power grids and posed new questions to be answered in the power system modeling, analysis and control. Automatic Generation Control (AGC must be extended to be able to accommodate the control of renewable generating assets. In addition, AGC is mandated to operate in accordance with the NERC‟s Control Performance Standard (CPS criteria, which represent a greater flexibility in relaxing the control of generating resources and yet assuring the stability and reliability of interconnected power systems when each balancing authority operates in full compliance. Enhancements in several aspects to the traditional AGC must be made in order to meet the aforementioned challenges. It is the intention of this paper to provide a systematic, mathematical formulation for AGC as a first attempt in the context of meeting the NERC CPS requirements and integrating renewable generating assets, which has not been seen reported in the literature to the best knowledge of the authors. Furthermore, this paper proposes neural network based predictive control schemes for AGC. The proposed controller is capable of handling complicated nonlinear dynamics in comparison with the conventional Proportional Integral (PI controller which is typically most effective to handle linear dynamics. The neural controller is designed in such a way that it has the capability of controlling the system generation in the relaxed manner so the ACE is controlled to a desired range instead of driving it to zero which would otherwise increase the control effort and cost; and most importantly the resulting system control performance meets the NERC CPS requirements and/or the NERC Balancing Authority’s ACE Limit (BAAL compliance requirements whichever are applicable.

  4. Diesel exhaust augments allergen-induced lower airway inflammation in allergic individuals: a controlled human exposure study.

    Science.gov (United States)

    Carlsten, Chris; Blomberg, Anders; Pui, Mandy; Sandstrom, Thomas; Wong, Sze Wing; Alexis, Neil; Hirota, Jeremy

    2016-01-01

    Traffic-related air pollution has been shown to augment allergy and airway disease. However, the enhancement of allergenic effects by diesel exhaust in particular is unproven in vivo in the human lung, and underlying details of this apparent synergy are poorly understood. To test the hypothesis that a 2 h inhalation of diesel exhaust augments lower airway inflammation and immune cell activation following segmental allergen challenge in atopic subjects. 18 blinded atopic volunteers were exposed to filtered air or 300 µg PM(2.5)/m(3) of diesel exhaust in random fashion. 1 h post-exposure, diluent-controlled segmental allergen challenge was performed; 2 days later, samples from the challenged segments were obtained by bronchoscopic lavage. Samples were analysed for markers and modifiers of allergic inflammation (eosinophils, Th2 cytokines) and adaptive immune cell activation. Mixed effects models with ordinal contrasts compared effects of single and combined exposures on these end points. Diesel exhaust augmented the allergen-induced increase in airway eosinophils, interleukin 5 (IL-5) and eosinophil cationic protein (ECP) and the GSTT1 null genotype was significantly associated with the augmented IL-5 response. Diesel exhaust alone also augmented markers of non-allergic inflammation and monocyte chemotactic protein (MCP)-1 and suppressed activity of macrophages and myeloid dendritic cells. Inhalation of diesel exhaust at environmentally relevant concentrations augments allergen-induced allergic inflammation in the lower airways of atopic individuals and the GSTT1 genotype enhances this response. Allergic individuals are a susceptible population to the deleterious airway effects of diesel exhaust. NCT01792232. 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/

  5. Control system for bearingless motor-generator

    Science.gov (United States)

    Kascak, Peter E. (Inventor); Jansen, Ralph H. (Inventor); Dever, Timothy P. (Inventor)

    2010-01-01

    A control system for an electromagnetic rotary drive for bearingless motor-generators comprises a winding configuration comprising a plurality of individual pole pairs through which phase current flows, each phase current producing both a lateral force and a torque. A motor-generator comprises a stator, a rotor supported for movement relative to the stator, and a control system. The motor-generator comprises a winding configuration supported by the stator. The winding configuration comprises at least three pole pairs through which phase current flows resulting in three three-phase systems. Each phase system has a first rotor reference frame axis current that produces a levitating force with no average torque and a second rotor reference frame axis current that produces torque.

  6. Digital gate pulse generator for cycloconverter control

    Science.gov (United States)

    Klein, Frederick F.; Mutone, Gioacchino A.

    1989-01-01

    The present invention provides a digital gate pulse generator which controls the output of a cycloconverter used for electrical power conversion applications by determining the timing and delivery of the firing pulses to the switching devices in the cycloconverter. Previous gate pulse generators have been built with largely analog or discrete digital circuitry which require many precision components and periodic adjustment. The gate pulse generator of the present invention utilizes digital techniques and a predetermined series of values to develop the necessary timing signals for firing the switching device. Each timing signal is compared with a reference signal to determine the exact firing time. The present invention is significantly more compact than previous gate pulse generators, responds quickly to changes in the output demand and requires only one precision component and no adjustments.

  7. Microprocessor control of a wind turbine generator

    Science.gov (United States)

    Gnecco, A. J.; Whitehead, G. T.

    1978-01-01

    This paper describes a microprocessor based system used to control the unattended operation of a wind turbine generator. The turbine and its microcomputer system are fully described with special emphasis on the wide variety of tasks performed by the microprocessor for the safe and efficient operation of the turbine. The flexibility, cost and reliability of the microprocessor were major factors in its selection.

  8. Possible applications of the LEAP motion controller for more interactive simulated experiments in augmented or virtual reality

    Science.gov (United States)

    Wozniak, Peter; Vauderwange, Oliver; Mandal, Avikarsha; Javahiraly, Nicolas; Curticapean, Dan

    2016-09-01

    Practical exercises are a crucial part of many curricula. Even simple exercises can improve the understanding of the underlying subject. Most experimental setups require special hardware. To carry out e. g. a lens experiments the students need access to an optical bench, various lenses, light sources, apertures and a screen. In our previous publication we demonstrated the use of augmented reality visualization techniques in order to let the students prepare with a simulated experimental setup. Within the context of our intended blended learning concept we want to utilize augmented or virtual reality techniques for stationary laboratory exercises. Unlike applications running on mobile devices, stationary setups can be extended more easily with additional interfaces and thus allow for more complex interactions and simulations in virtual reality (VR) and augmented reality (AR). The most significant difference is the possibility to allow interactions beyond touching a screen. The LEAP Motion controller is a small inexpensive device that allows for the tracking of the user's hands and fingers in three dimensions. It is conceivable to allow the user to interact with the simulation's virtual elements by the user's very hand position, movement and gesture. In this paper we evaluate possible applications of the LEAP Motion controller for simulated experiments in augmented and virtual reality. We pay particular attention to the devices strengths and weaknesses and want to point out useful and less useful application scenarios.

  9. Vertebral Augmentation After Recent Randomized Controlled Trials: A New Rise in Kyphoplasty Volumes.

    Science.gov (United States)

    Cox, Mougnyan; Levin, David C; Parker, Laurence; Morrison, William; Long, Suzanne; Rao, Vijay M

    2016-01-01

    In 2009, the results of two randomized controlled trials refuting the effectiveness of vertebroplasty compared with sham procedures were published in a leading journal. The purpose of the present study was to evaluate the impact of these randomized trials on subsequent volume and utilization rates of vertebral augmentation (VA) in the United States. Using nationwide Medicare Part B databases, Current Procedural Terminology, version 4, codes for thoracic and lumbar vertebroplasty and kyphoplasty were studied from 2006 to 2013 (codes 22520 to 22525). The total volumes of procedures were determined and utilization rates were calculated. Volumes and rates by provider specialty were also studied. The total volume of VA procedures peaked in 2008 at 101,807 and thereafter fell steadily to 80,940 in 2013. The utilization rates per 100,000 beneficiaries also showed a similar trend. Radiologists performed the largest number of VA procedures in 2013 (33,618 procedures [42%]), followed by orthopedic surgeons (19,886 procedures [25%]). After 2009, vertebroplasty volumes decreased sharply. Kyphoplasty volumes increased in 2011, after an initial decrease in 2010. The divergent trend in the volumes of the two procedures persisted through 2013. After the publication of the two trials' results in 2009, vertebroplasty volumes and rates decreased sharply. However, there is an emerging trend toward performing more kyphoplasty procedures, mitigating the decrease in total volume of VA procedures. Radiologists have the strongest role in performing these procedures among all medical specialties. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  10. Augmented reality-based postural control training improves gait function in patients with stroke: Randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Chi-Ho Lee, PT, MSc

    2014-12-01

    Full Text Available The purpose of this study was to determine the effects of augmented reality (AR-based postural control training on balance and gait function in stroke patients. Twenty-one stroke patients were assigned to either an experimental group (n = 10 or a control group (n = 11. Patients in both groups received a general physical therapy program for a duration of 30 minutes per session, 5 days per week, for a period of 4 weeks. Participants in the experimental group received additional AR-based postural control training for 30 minutes per day, 3 days per week, for a period of 4 weeks. Patients were assessed with the timed up-and-go test, Berg Balance Scale test, and spatiotemporal parameters using the GAITRite system. Results of repeated-measures analysis of covariance showed a significant main effect of time on timed up-and-go test, Berg Balance Scale, velocity, cadence, step length and stride length of paretic and nonparetic sides. In addition, walking velocity, step length, and stride length on both the paretic and nonparetic sides showed a significant group × time interaction effect. The results of this study provide evidence in support of incorporating an AR environment into postural control training for improving gait of stroke patients.

  11. Synchronous generator wind energy conversion control system

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  12. Towards Intelligent Control for Next Generation Aircraft

    Science.gov (United States)

    Acosta, Diana Michelle; KrishnaKumar, Kalmanje Srinvas; Frost, Susan Alane

    2008-01-01

    NASA Aeronautics Subsonic Fixed Wing Project is focused on mitigating the environmental and operation impacts expected as aviation operations triple by 2025. The approach is to extend technological capabilities and explore novel civil transport configurations that reduce noise, emissions, fuel consumption and field length. Two Next Generation (NextGen) aircraft have been identified to meet the Subsonic Fixed Wing Project goals - these are the Hybrid Wing-Body (HWB) and Cruise Efficient Short Take-Off and Landing (CESTOL) aircraft. The technologies and concepts developed for these aircraft complicate the vehicle s design and operation. In this paper, flight control challenges for NextGen aircraft are described. The objective of this paper is to examine the potential of state-of-the-art control architectures and algorithms to meet the challenges and needed performance metrics for NextGen flight control. A broad range of conventional and intelligent control approaches are considered, including dynamic inversion control, integrated flight-propulsion control, control allocation, adaptive dynamic inversion control, data-based predictive control and reinforcement learning control.

  13. Comparison between amniotomy, oxytocin or both for augmentation of labor in prolonged latent phase: a randomized controlled trial.

    Science.gov (United States)

    Nachum, Zohar; Garmi, Gali; Kadan, Yfat; Zafran, Noah; Shalev, Eliezer; Salim, Raed

    2010-11-07

    A prolonged latent phase is independently associated with an increased incidence of subsequent labor abnormalities. We aimed to compare between oxytocin augmentation, amniotomy and a combination of both on the duration of labor among women with a prolonged latent phase. Women with a singleton fetus in cephalic presentation who have a prolonged latent phase, were randomly allocated to amniotomy (group 1), oxytocin (group 2) or both (group 3). A group of women who progressed spontaneously without intervention composed the control group (group 4). The primary outcome was the duration of time from initiation of augmentation until delivery. A total of 213 women were consented and randomized to group 1 (70 women), group 2 (72 women) and group 3 (71 women). Group 4 was composed from additional 70 women. A mean reduction of 120 minutes in labor duration was observed among group 3 compared to group 1 (p = 0.08) and 180 minutes compared to group 2 and 4 (p = 0.001). Women in group 3 had a shorter length of time from augmentation until the beginning of the active phase and a shorter first stage of labor than group 1 (p = 0.03), group 2 (p = 0.001) and group 4 (p = 0.001). Satisfaction was greater among group 3 and 4. Mode of delivery and neonatal outcome were comparable between the groups. Labor augmentation by combined amniotomy and oxytocin among women with a prolonged latent phase at term seems superior compared to either of them alone.

  14. Mine Drainage Generation and Control Options.

    Science.gov (United States)

    Wei, Xinchao; Rodak, Carolyn M; Zhang, Shicheng; Han, Yuexin; Wolfe, F Andrew

    2016-10-01

    This review provides a snapshot of papers published in 2015 relevant to the topic of mine drainage generation and control options. The review is broken into 3 sections: Generation, Prediction and Prevention, and Treatment Options. The first section, mine drainage generation, focuses on the characterization of mine drainage and the environmental impacts. As such, it is broken into three subsections focused on microbiological characterization, physiochemical characterization, and environmental impacts. The second section of the review is divided into two subsections focused on either the prediction or prevention of acid mine drainage. The final section focuses on treatment options for mine drainage and waste sludge. The third section contains subsections on passive treatment, biological treatment, physiochemical treatment, and a new subsection on beneficial uses for mine drainage and treatment wastes.

  15. Generation and control of acoustic cavitation structure.

    Science.gov (United States)

    Bai, Lixin; Xu, Weilin; Deng, Jingjun; Li, Chao; Xu, Delong; Gao, Yandong

    2014-09-01

    The generation and control of acoustic cavitation structure are a prerequisite for application of cavitation in the field of ultrasonic sonochemistry and ultrasonic cleaning. The generation and control of several typical acoustic cavitation structures (conical bubble structure, smoker, acoustic Lichtenberg figure, tailing bubble structure, jet-induced bubble structures) in a 20-50 kHz ultrasonic field are investigated. Cavitation bubbles tend to move along the direction of pressure drop in the region in front of radiating surface, which are the premise and the foundation of some strong acoustic cavitation structure formation. The nuclei source of above-mentioned acoustic cavitation structures is analyzed. The relationship and mutual transformation of these acoustic cavitation structures are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Digital Illumination for Augmented Studios

    OpenAIRE

    Bimber, Oliver; Grundhöfer, Anselm; Zollmann, Stefanie; Kolster, Daniel

    2006-01-01

    Virtual studio technology plays an important role for modern television productions. Blue-screen matting is a common technique for integrating real actors or moderators into computer generated sceneries. Augmented reality offers the possibility to mix real and virtual in a more general context. This article proposes a new technological approach for combining real studio content with computergenerated information. Digital light projection allows a controlled spatial, temporal, chrominance a...

  17. Computer numeric control generation of toric surfaces

    Science.gov (United States)

    Bradley, Norman D.; Ball, Gary A.; Keller, John R.

    1994-05-01

    Until recently, the manufacture of toric ophthalmic lenses relied largely upon expensive, manual techniques for generation and polishing. Recent gains in computer numeric control (CNC) technology and tooling enable lens designers to employ single- point diamond, fly-cutting methods in the production of torics. Fly-cutting methods continue to improve, significantly expanding lens design possibilities while lowering production costs. Advantages of CNC fly cutting include precise control of surface geometry, rapid production with high throughput, and high-quality lens surface finishes requiring minimal polishing. As accessibility and affordability increase within the ophthalmic market, torics promise to dramatically expand lens design choices available to consumers.

  18. Adaptive Dynamic Surface Control for Generator Excitation Control System

    Directory of Open Access Journals (Sweden)

    Zhang Xiu-yu

    2014-01-01

    Full Text Available For the generator excitation control system which is equipped with static var compensator (SVC and unknown parameters, a novel adaptive dynamic surface control scheme is proposed based on neural network and tracking error transformed function with the following features: (1 the transformation of the excitation generator model to the linear systems is omitted; (2 the prespecified performance of the tracking error can be guaranteed by combining with the tracking error transformed function; (3 the computational burden is greatly reduced by estimating the norm of the weighted vector of neural network instead of the weighted vector itself; therefore, it is more suitable for the real time control; and (4 the explosion of complicity problem inherent in the backstepping control can be eliminated. It is proved that the new scheme can make the system semiglobally uniformly ultimately bounded. Simulation results show the effectiveness of this control scheme.

  19. Augmented Adaptive Control of a Wind Turbine in the Presence of Structural Modes

    Science.gov (United States)

    Frost, Susan A.; Balas, Mark J.; Wright, Alan D.

    2010-01-01

    Wind turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, potentially causing component fatigue and failure. Two key technology drivers for turbine manufacturers are increasing turbine up time and reducing maintenance costs. Since the trend in wind turbine design is towards larger, more flexible turbines with lower frequency structural modes, manufacturers will want to develop methods to operate in the presence of these modes. Accurate models of the dynamic characteristics of new wind turbines are often not available due to the complexity and expense of the modeling task, making wind turbines ideally suited to adaptive control. In this paper, we develop theory for adaptive control with rejection of disturbances in the presence of modes that inhibit the controller. We use this method to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the interference of certain structural modes in feedback. The control objective is accomplished by collectively pitching the turbine blades. The adaptive pitch controller for Region 3 is compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller.

  20. Sensor-augmented pump therapy lowers HbA(1c) in suboptimally controlled Type 1 diabetes; a randomized controlled trial

    NARCIS (Netherlands)

    Hermanides, J.; Nørgaard, K.; Bruttomesso, D.; Mathieu, C.; Frid, A.; Dayan, C. M.; Diem, P.; Fermon, C.; Wentholt, I. M. E.; Hoekstra, J. B. L.; DeVries, J. H.

    2011-01-01

    To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes. In this investigator-initiated multi-centre trial (the Eurythmics Trial) in eight outpatient centres in Europe, we randomized 83 patients with

  1. A piloted simulator investigation of static stability and stability/control augmentation effects on helicopter handling qualities for instrument approach

    Science.gov (United States)

    Lebacqz, J. V.; Forrest, R. D.

    1980-01-01

    A ground simulator experiment was conducted on the Flight Simulator for Advanced Aircraft at Ames Research Center to investigate the influence of several static stability and stability/control augmentation design parameters on helicopter flying qualities during terminal area operations in instrument conditions. Effects of light turbulence were included. Two levels of static stability in each rotational axis (pitch, roll, yaw) were examined for a hingeless rotor configuration. The variations in pitch and roll were: (1) stable and (2) neutral static stability; in yaw there were two stable levels. Four types of stability/control augmentation were also examined for the lower level of static stability in each axis. This latter investigation covered three helicopter rotor types: hingeless, articulated, and teetering. Four pilots performed a total of 105 evaluations of these parameters for a representative VOR instrument approach task. Pilot rating results indicate the acceptability of neutral static stability longitudinally and laterally and the need for pitch-roll attitude augmentation to achieve a satisfactory system.

  2. Adaptive Augmenting Control Flight Characterization Experiment on an F/A-18

    Science.gov (United States)

    VanZwieten, Tannen S.; Orr, Jeb S.; Wall, John H.; Gilligan, Eric T.

    2014-01-01

    This paper summarizes the Adaptive Augmenting Control (AAC) flight characterization experiments performed using an F/A-18 (TN 853). AAC was designed and developed specifically for launch vehicles, and is currently part of the baseline autopilot design for NASA's Space Launch System (SLS). The scope covered here includes a brief overview of the algorithm (covered in more detail elsewhere), motivation and benefits of flight testing, top-level SLS flight test objectives, applicability of the F/A-18 as a platform for testing a launch vehicle control design, test cases designed to fully vet the AAC algorithm, flight test results, and conclusions regarding the functionality of AAC. The AAC algorithm developed at Marshall Space Flight Center is a forward loop gain multiplicative adaptive algorithm that modifies the total attitude control system gain in response to sensed model errors or undesirable parasitic mode resonances. The AAC algorithm provides the capability to improve or decrease performance by balancing attitude tracking with the mitigation of parasitic dynamics, such as control-structure interaction or servo-actuator limit cycles. In the case of the latter, if unmodeled or mismodeled parasitic dynamics are present that would otherwise result in a closed-loop instability or near instability, the adaptive controller decreases the total loop gain to reduce the interaction between these dynamics and the controller. This is in contrast to traditional adaptive control logic, which focuses on improving performance by increasing gain. The computationally simple AAC attitude control algorithm has stability properties that are reconcilable in the context of classical frequency-domain criteria (i.e., gain and phase margin). The algorithm assumes that the baseline attitude control design is well-tuned for a nominal trajectory and is designed to adapt only when necessary. Furthermore, the adaptation is attracted to the nominal design and adapts only on an as-needed basis

  3. Control of cascaded induction generator systems

    Science.gov (United States)

    Ortmeyer, T. H.

    1984-12-01

    This report documents an investigation of the stability and control of cascaded doubly fed machines (CDFM). These machines are brushless variable speed constant frequency electric power generators with potential for application in aircraft. A previous analytical study indicated the CDFM system would be controllable in the subsynchronous operating mode with a passive RL load. The present study contains two steps. First is an investigation of the machine operation in the supersynchronous mode. The second step is an investigation of machine operation with output capacitors providing excitation VARs for the machine and load. Step 1 results show that the machines exhibit stability characteristics in the supersynchronous mode similar to those observed in the subsynchronous mode. Step 2 results show that output capacitors degrade the system performance, particularly at light loads. The results show that output current feedback can be employed to improve the system performance.

  4. Variable speed wind turbine generator system with current controlled voltage source inverter

    Energy Technology Data Exchange (ETDEWEB)

    Muyeen, S.M., E-mail: muyeen0809@yahoo.co [Dept. of Electrical Engineering, Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); Al-Durra, Ahmed [Dept. of Electrical Engineering, The Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); Tamura, J. [Dept. of EEE, Kitami Institute of Technology, 165 Koen-cho, Kitami 090-8507 (Japan)

    2011-07-15

    highlights: {yields} Current controlled voltage source inverter scheme for wind power application. {yields} Low voltage ride through of wind farm. {yields} Variable speed wind turbine driven permanent magnet synchronous generator-operation and control. -- Abstract: The present popular trend of wind power generation is to use variable speed wind turbine (VSWT) driving a doubly fed induction generator (DFIG), wound field synchronous generator (WFSG) or permanent magnet synchronous generator (PMSG). Among them, stability analyses of DFIG type of VSWT have already been reported in many literatures. However, transient stability and low voltage ride through (LVRT) characteristics analyses for synchronous generator type of VSWT is not sufficient enough. This paper focuses on detailed LVRT characteristic analysis of variable speed wind turbine driving a PMSG (VSWT-PMSG) with current controlled voltage source inverter (CC-VSI). Modeling and suitable control strategies for overall system are developed to augment the low voltage ride through capability of variable speed wind generator, considering recent wind farm grid code. Both symmetrical and unsymmetrical faults are analyzed as network disturbances in this paper. The permanent fault due to unsuccessful reclosing of circuit breakers is taken into consideration, which is a salient feature of this study. Moreover, the dynamic characteristic is analyzed using real wind speed data measured in Hokkaido Island, Japan. The proposed control scheme is simulated by using the standard power system simulation package PSCAD/EMTDC and results are verified by comparing that of voltage controlled voltage source inverter scheme available in power system literature.

  5. Sentinel lymph node detection after trans axillary augmentation mammoplasty: a prospective controlled study utilizing lymphoscintigraphy in 43 breasts

    Energy Technology Data Exchange (ETDEWEB)

    Sado, Heitor Naoki; Timi, Jorge Rufino Ribas; Matias, Jorge Eduardo Fouto [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Program of Post-Graduation in Surgical Practice]. E-mail: heitor@cermen.com.br; Graf, Ruth Maria [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Hospital de Clinicas; Urban, Cicero Andrade [UnicenP, Curitiba, PR (Brazil); Yamada, Airton Seiji [CERMEN - Centro de Radioimunoensaio e Medicina Nuclear de Curitiba, PR (Brazil); Woellner, Luiz Carlos [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Hospital de Clinicas. Unit of Nuclear Medicine; Ferreira, Eduardo de Castro [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Hospital de Clinicas

    2008-09-15

    Objective: to evaluate the potential influence of trans axillary augmentation mammoplasty on future detection of sentinel lymph node. Materials and methods: prospective controlled study where 22 patients were selected and divided into two groups (post-mammoplasty and control) corresponding to 43 breasts (22 in the post-mammoplasty group and 21 in the control group) evaluated by lymphoscintigraphy immediately after periareolar {sup 99m}Tc-phytate injections. In the statistical analysis, p values < 0.05 were considered as significant. Results: all the breasts in the post-mammoplasty group presented lymphatic drainage to the axillary chain, with no difference as compared with the control group (p 0.488). The average number of hot lymph nodes was 1.27 {+-} 0.46 in the post-mammoplasty group, and 1.33 {+-} 0.58 in the control group (p = 0.895). The mean time required to visualize the first lymph node was 3.14 {+-} 4.42 minutes in the post mammoplasty group, and 5.48 {+-} 5.06 minutes in the control group (p 0.136). Conclusion: transaxillary augmentation mammoplasty did not affect the future detection of sentinel lymph node. (author)

  6. Sentinel lymph node detection after transaxillary augmentation mammoplasty: a prospective controlled study utilizing lymphoscintigraphy in 43 breasts

    Energy Technology Data Exchange (ETDEWEB)

    Sado, Heitor Naoki; Yamada, Airton Seiji [Centro de Radioimunoensaio e Medicina Nuclear do Parana (CERMEN), Curitiba, PR (Brazil)]. E-mail: heitor@cermen.com.br; Graf, Ruth Maria; Timi, Jorge Rufino Ribas; Matias, Jorge Eduardo Fouto [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Hospital de Clinicas. Cirurgia Plastica; Urban, Cicero Andrade [Universidade Posotivo (UnicenP), Curitiba, PR (Brazil). Centro Universitario Positivo; Woellner, Luiz Carlos [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Hospital de Clinicas. Medicina Nuclear; Ferreira, Eduardo de Castro [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Hospital Universitario

    2008-09-15

    Objective: To evaluate the potential influence of transaxillary augmentation mammoplasty on future detection of sentinel lymph node. Materials and methods: Prospective controlled study where 22 patients were selected and divided into two groups (post-mammoplasty and control) corresponding to 43 breasts (22 in the post-mammoplasty group and 21 in the control group) evaluated by lymphoscintigraphy immediately after periareolar {sup 99m}Tc-phytate injections. In the statistical analysis, p values < 0.05 were considered as significant. Results: All the breasts in the post-mammoplasty group presented lymphatic drainage to the axillary chain, with no difference as compared with the control group (p 0.488). The average number of hot lymph nodes was 1.27 {+-} 0.46 in the post-mammoplasty group, and 1.33 {+-} 0.58 in the control group (p = 0.895). The mean time required to visualize the first lymph node was 3.14 {+-} 4.42 minutes in the post mammoplasty group, and 5.48 {+-} 5.06 minutes in the control group (p 0.136). Conclusion: Transaxillary augmentation mammoplasty did not affect the future detection of sentinel lymph node. (author)

  7. Controlled Electrospray Generation of Nonspherical Alginate Microparticles.

    Science.gov (United States)

    Jeyhani, Morteza; Mak, Sze Yi; Sammut, Stephen; Shum, Ho Cheung; Hwang, Dae Kun; Tsai, Scott S H

    2017-12-11

    Electrospraying is a technique used to generate microparticles in a high throughput manner. For biomedical applications, a biocompatible electrosprayed material is often desirable. Using polymers, such as alginate hydrogels, makes it possible to create biocompatible and biodegradable microparticles that can be used for cell encapsulation, to be employed as drug carriers, and for use in 3D cell culturing. Evidence in the literature suggests that the morphology of the biocompatible microparticles is relevant in controlling the dynamics of the microparticles in drug delivery and 3D cell culturing applications. Yet, most electrospray-based techniques only form spherical microparticles, and there is currently no widely adopted technique for producing nonspherical microparticles at a high throughput. Here, we demonstrate the generation of nonspherical biocompatible alginate microparticles by electrospraying, and control the shape of the microparticles by varying experimental parameters such as chemical concentration and the distance between the electrospray tip and the particle-solidification bath. Importantly, we show that these changes to the experimental setup enable the synthesis of different shaped particles, and the systematic change in parameters, such as chemical concentration, result in monotonic changes to the particle aspect ratio. We expect that these results will find utility in many biomedical applications that require biocompatible microparticles of specific shapes. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Comparison between amniotomy, oxytocin or both for augmentation of labor in prolonged latent phase: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Shalev Eliezer

    2010-11-01

    Full Text Available Abstract Background A prolonged latent phase is independently associated with an increased incidence of subsequent labor abnormalities. We aimed to compare between oxytocin augmentation, amniotomy and a combination of both on the duration of labor among women with a prolonged latent phase. Methods Women with a singleton fetus in cephalic presentation who have a prolonged latent phase, were randomly allocated to amniotomy (group 1, oxytocin (group 2 or both (group 3. A group of women who progressed spontaneously without intervention composed the control group (group 4. The primary outcome was the duration of time from initiation of augmentation until delivery. Results A total of 213 women were consented and randomized to group 1 (70 women, group 2 (72 women and group 3 (71 women. Group 4 was composed from additional 70 women. A mean reduction of 120 minutes in labor duration was observed among group 3 compared to group 1 (p = 0.08 and 180 minutes compared to group 2 and 4 (p = 0.001. Women in group 3 had a shorter length of time from augmentation until the beginning of the active phase and a shorter first stage of labor than group 1 (p = 0.03, group 2 (p = 0.001 and group 4 (p = 0.001. Satisfaction was greater among group 3 and 4. Mode of delivery and neonatal outcome were comparable between the groups. Conclusion Labor augmentation by combined amniotomy and oxytocin among women with a prolonged latent phase at term seems superior compared to either of them alone.

  9. Attention bias modification augments cognitive-behavioral group therapy for social anxiety disorder: a randomized controlled trial.

    Science.gov (United States)

    Lazarov, Amit; Marom, Sofi; Yahalom, Naomi; Pine, Daniel S; Hermesh, Haggai; Bar-Haim, Yair

    2017-12-20

    Cognitive-behavioral group therapy (CBGT) is a first-line treatment for social anxiety disorder (SAD). However, since many patients remain symptomatic post-treatment, there is a need for augmenting procedures. This randomized controlled trial (RCT) examined the potential augmentation effect of attention bias modification (ABM) for CBGT. Fifty patients with SAD from three therapy groups were randomized to receive an 18-week standard CBGT with either ABM designed to shift attention away from threat (CBGT + ABM), or a placebo protocol not designed to modify threat-related attention (CBGT + placebo). Therapy groups took place in a large mental health center. Clinician and self-report measures of social anxiety and depression were acquired pre-treatment, post-treatment, and at 3-month follow-up. Attention bias was assessed at pre- and post-treatment. Patients randomized to the CBGT + ABM group, relative to those randomized to the CBGT + placebo group, showed greater reductions in clinician-rated SAD symptoms post-treatment, with effects maintained at 3-month follow-up. Group differences were not evident for self-report or attention-bias measures, with similar reductions in both groups. Finally, reduction in attention bias did not mediate the association between group and reduction in Liebowitz Social Anxiety Scale Structured Interview (LSAS) scores. This is the first RCT to examine the possible augmenting effect of ABM added to group-based cognitive-behavioral therapy for adult SAD. Training patients' attention away from threat might augment the treatment response to standard CBGT in SAD, a possibility that could be further evaluated in large-scale RCTs.

  10. A Piloted Simulator Investigation of Side-Stick Controller/Stability and Control Augmentation System Requirements for Helicopter Visual Flight Tasks,

    Science.gov (United States)

    1983-05-01

    Simulation Program: Vol- flight handling qualities without pilot selection, ume I-Mathematical Model", NASA the contril laws required automatic phasing...acteristics and level of stability and control The Phase 2 simulation experiment, the subject augmentation on handling qualities for several of this paper...handling qualities under VMC and empha- speed and forward flight control laws were im- sized tasks which represented elements of the plemented, and a

  11. Interactive augmented reality

    OpenAIRE

    Moret Gabarró, Roger

    2010-01-01

    Projecte final de carrera realitzat en col.laboració amb el Royal Institute of Technology Augmented reality can provide a new experience to users by adding virtual objects where they are relevant in the real world. The new generation of mobile phones offers a platform to develop augmented reality application for industry as well as for the general public. Although some applications are reaching commercial viability, the technology is still limited. The main problem designers have to face w...

  12. Adaptive Augmented Reality: Plasticity of Augmentations

    OpenAIRE

    Ghouaiel, Nehla; Cieutat, Jean-Marc; JESSEL, Jean-Pierre

    2014-01-01

    International audience; An augmented reality system is used to complete the real world with virtual objects (computer generated) so they seem to coexist in the same space as the real world. The concept of plasticity [4][5] was first introduced for Human Computer Interaction (HCI). It denotes the ability of an HCI interface to fit the context of use defined by the user, the environment and the platform. We believe that plasticity is a very important notion in the domain of augmented reality. T...

  13. AUGMENTED REALITY

    DEFF Research Database (Denmark)

    Skov, Kirsten; Bahn, Anne Louise

    2017-01-01

    Projektets grundlæggende idé er udvikling af visuel, æstetisk læring med Augmented Reality, hvor intentionen er at bidrage med konkrete undersøgelser og udforskning af begrebet Augmented Reality – herunder koblingen mellem det analoge og digitale i forhold til læring, multimodalitet og it...

  14. Augmented Reality

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher; Kjeldsen, Lars Peter Bech; Rahn, Annette

    2015-01-01

    This chapter describes the use of iPad-facilitated application of augmented reality in the teaching of highly complex anatomical and physiological subjects in the training of nurses at undergraduate level. The general aim of the project is to investigate the potentials of this application in terms...... of augmented reality are discussed....

  15. Socket augmentation

    OpenAIRE

    Shalu Chandna; Kimpreet Kaur; Navkiran Kaur; Anish Manocha

    2015-01-01

    Introduction of dental implants have come to the forefront of modern odontology. A successful osseointegration demands an ideal quantity and quality of alveolar bone. Socket augmentation techniques are effective in minimizing postextraction alveolar ridge resorption. The aim of this paper is to review the available literature on socket augmentation with special focus on its relation with implant.

  16. Socket augmentation

    Directory of Open Access Journals (Sweden)

    Shalu Chandna

    2015-01-01

    Full Text Available Introduction of dental implants have come to the forefront of modern odontology. A successful osseointegration demands an ideal quantity and quality of alveolar bone. Socket augmentation techniques are effective in minimizing postextraction alveolar ridge resorption. The aim of this paper is to review the available literature on socket augmentation with special focus on its relation with implant.

  17. Computer-Controlled Force Generator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TDA Research, Inc. is developing a compact, low power, Next-Generation Exercise Device (NGRED) that can generate any force between 5 and 600 lbf. We use a closed...

  18. An investigation of side-stick-controller/stability and control-augmentation system requirements for helicopter terrain flight under reduced visibility conditions

    Science.gov (United States)

    Landis, K. H.; Glusman, S. I.; Aiken, E. W.; Hilbert, K. B.

    1984-01-01

    Simulation of the reduced visibility tasks is effected by providing the pilot with a visually coupled, helmet-mounted display of flight-control symbols superimposed upon terrain-board imagery. Forward-flight, low-speed, and precision-hover control modes are implemented, and a method is developed for the blending of control laws between each control mode. An investigation is made of the variations in the level of integration of primary control functions on a single side-stick controller. For most of the flight tasks investigated, separated controller configurations are preferred to a single, fully integrated side-stick device. Satisfactory handling qualities over all controller configurations are attained only for a precision-hover task conducted with a high level of stability and control augmentation. For most tasks flown with the helmet-mounted display significant degradation in handling qualities occurs relative to the identical tasks flown under visual flight conditions.

  19. Respirator triggering of electron-beam computed tomography (EBCT): differences in dynamic changes between augmented ventilation and controlled mechanical ventilation

    Science.gov (United States)

    Recheis, Wolfgang A.; Kleinsasser, Axel; Schuster, Antonius H.; Loeckinger, Alexander; Frede, Thomas; Springer, Peter; Hoermann, Christoph; zur Nedden, Dieter

    2000-04-01

    The purpose was to evaluate differences in dynamic changes of the lung aeration (air-tissue ratio) between augmented modes of ventilation (AMV) and controlled mechanical ventilation (CMV) in normal subjects. 4 volunteers, ventilated with the different respirator protocols via face mask, were scanned using the EBCT in the 50 ms mode. A software analyzed the respirator's digitized pressure and volume signals of two subsequent ventilation phases. Using these values it was possible to calculate the onset of inspiration or expiration of the next respiratory phase. The calculated starting point was then used to trigger the EBCT. The dynamic changes of air- tissue ratios were evaluated in three separate regions: a ventral, an intermediate and a dorsal area. AMV results in increase of air-tissue ratio in the dorsal lung area due to the active contraction of the diaphragm, whereas CMV results in a more pronounced increase in air-tissue ratio of the ventral lung area. This study gives further insight into the dynamic changes of the lung's biomechanics by comparing augmented ventilation and controlled mechanical ventilation in the healthy proband.

  20. Augmented reality

    National Research Council Canada - National Science Library

    Patrik Pucer

    2011-01-01

    .... In such a mixed reality, real and virtual objects coexist in the same environment. The reality, where users watch and use the real environment upgraded with virtual objects is called augmented reality...

  1. Breast Augmentation

    Science.gov (United States)

    ... augmentation About Doctors & Departments Care at Mayo Clinic Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  2. Effectiveness of Aerobic Exercise as an Augmentation Therapy for Inpatients with Major Depressive Disorder: A Preliminary Randomized Controlled Trial.

    Science.gov (United States)

    Shachar-Malach, Tal; Cooper Kazaz, Rena; Constantini, Naama; Lifschytz, Tzuri; Lerer, Bernard

    2015-01-01

    Physical exercise has been shown to reduce depressive symptoms when used in combination with antidepressant medication. We report a randomized controlled trial of aerobic exercise compared to stretching as an augmentation strategy for hospitalized patients with major depression. Male or female patients, 18-80 years, diagnosed with a Major Depressive Episode, were randomly assigned to three weeks of augmentation therapy with aerobic (n=6) or stretching exercise (n=6). Depression was rated, at several time points using the 21-item Hamilton Depression Scale (HAM-D), Beck Depression Inventory (BDI) and other scales. According to the HAM-D, there were four (out of six) responders in the aerobic group, two of whom achieved remission, and none in the stretching group. According to the BDI, there were two responders in the aerobic group who were also remitters and none in the stretching group. The results of this small study suggest that aerobic exercise significantly improves treatment outcome when added to antidepressant medication. However, due to the small sample size the results must be regarded as preliminary and further studies are needed to confirm the findings.

  3. Expanded vs. dense polytetrafluoroethylene membranes in vertical ridge augmentation around dental implants: a prospective randomized controlled clinical trial.

    Science.gov (United States)

    Ronda, Marco; Rebaudi, Alberto; Torelli, Lucio; Stacchi, Claudio

    2014-07-01

    This prospective randomized controlled trial was designed to test the performance of titanium-reinforced dense polytetrafluoroethylene (d-PTFE) membrane vs. titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) membrane in achieving vertical bone regeneration, both associated with a composite grafting material. The study enrolled 23 patients requiring bone augmentation with guided bone regeneration (GBR) procedures for placing implants in atrophic posterior mandibles (available bone height membrane (control) or a d-PTFE membrane (test). Membrane removal was performed after 6 months, and changes in bone height were recorded. Seventy-eight implants were inserted in 26 mandibular sites contextually to vertical ridge augmentation procedures. The healing period was uneventful in all sites, and the vertical defects were satisfactorily filled with a newly formed hard tissue. Mean defect fill after 6 months was 5.49 mm (SD ± 1.58) at test sites and 4.91 mm (SD ± 1.78) at control sites. The normalized data (percentage changes against baseline) did not show any statistically significant difference between test and control groups (P = NS). Based on the data from this study, both d-PTFE and e-PTFE membranes showed identical clinical results in the treatment of vertical bone defects around implants, using the GBR technique. The membrane removal procedure was easier to perform in the d-PTFE group than in the e-PTFE group. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  4. Control of Permanent Magnet Synchronous Generator for large wind turbines

    DEFF Research Database (Denmark)

    Busca, Cristian; Stan, Ana-Irina; Stanciu, Tiberiu

    2010-01-01

    Direct Torque Control (DTC) and Field Oriented Control (FOC) are the most dominant control strategies used in generators for wind turbines. In this paper both control methods were implemented on a Permanent Magnet Synchronous Generator (PMSG). The variable speed wind turbine with full scale power...

  5. Mastopexia de aumento, técnica de quinta generación Augmentation mastopexy, fifth generation technique

    Directory of Open Access Journals (Sweden)

    R. Navarro

    2008-06-01

    traditional marks. If breasts were small, implants were positioned by submuscular way, and if bigger, the way was retroglandular. For recidivism prevention, it was positioned 2 internal straps; if the gland-implant was bigger and heavier an immobile strap from the breast to the clavicle periostium and to the 3rd rib, was realized; if it would result smaller or median size only were fixed to the third ribs with a dermal flap. Controls were realized between 1 month to 3 years. Ptosis was corrected between 5 to 12cm without any recidivism, neither post surgery pseudo-ptosis. With the support of an elastic brassier, physical exercise is recommended after 15 days. The scarring was highly satisfactory. Complications were partial disruptions in 2 patients and ardors, tautness sensation and areolar enlargement in patients with more than 12cm ptosis and wide areola. Because of the execution simplicity and security, surgery was ambulatory. We propose this technique called 5th generation that precludes the periareolar, the inframamary, the vertical and the T scar; partial elimination of both upper breasts quadrants lessen the possibility of breast cancer in this upper area and ptosis recidivism by the use of the internal straps.

  6. Mental Workload and Situational Awareness Evaluation of APR1400 Engineered Safety Features- Component Control Activation Systems using Augmented Reality

    Energy Technology Data Exchange (ETDEWEB)

    Murungi, Mwongeera; Jung, JaeCheon [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2016-10-15

    In the study, an Augmented Reality procedure guidance support system concept was designed and used as a tool for the measurement of mental workload and Situational awareness of an SRO (Senior Reactor Operator). The EOP was chosen as the scenario for testing because it is the one of the critical plant conditions that requires human intervention and it represents (one of the more) conservative approaches to the test scenarios that are possible. The system is expected to realize an improvement in the level of Situational Awareness and mental workload which have been demonstrated by previous studies to be directly linked with the system response to an emergency situation in the MCR. The planning and design of the project adhered to a Systems Engineering approach in order to provide an optimized framework for ensuring the successful implementation of the system design. Previous study and research into this topic has emphasized the importance of situational awareness in determining the human factor performance issues in the nuclear power plant Control Room operations. This paper broadly defined a technique that successfully used the operator’s mental workload (using NASATLX) and Situational Awareness (using SART) as quantifying measures to evaluate the performance of specific ESF-CCS functions based on human factors. These results show that an improvement of the SA/workload could lead to an improvement of the level of certainty that the emergency situation can be brought under control. It is expected that future development work in this area will yield an actualized Augmented Reality system that could incorporate MCR team control and possibly be implemented in the system validation of other I and C systems.

  7. Amantadine as Augmentation in Managing Opioid Withdrawal with Clonidine: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Shahrokh Amiri

    2014-09-01

    Full Text Available Withdrawal symptoms are a main reason of continuous use of opioid. This study compares the efficacy of augmentation of amantadine with clonidine in decreasing opioid withdrawal symptoms.This double-blind randomized clinical trial was carried out in the detoxification and rehabilitation inpatient ward at Razi Hospital, Tabriz, Iran during 2012. The patients were randomly assigned to receive clonidine or clonidine plus amantadine; and withdrawal symptoms were evaluated in the admission day and 24, 48, and 72 hours later. Data were analyzed using SPSS by the 2*2 repeated analyses of variances (ANOVA.From the total of 69 participants, 30 patients completed the trial in each group. The severity of symptoms, however, had an increasing trend in both groups. Analysis of variance of the symptom severity score (by The Clinical Opiate Withdrawal Scale revealed a significant group-time interaction, and the patients who were receiving amantadine experienced milder symptoms.Treatment of opioid withdrawal symptoms with amantadine and clonidine would result in a better outcome compared with clonidine alone.

  8. Intelligent Distribution Voltage Control with Distributed Generation =

    Science.gov (United States)

    Castro Mendieta, Jose

    In this thesis, three methods for the optimal participation of the reactive power of distributed generations (DGs) in unbalanced distributed network have been proposed, developed, and tested. These new methods were developed with the objectives of maintain voltage within permissible limits and reduce losses. The first method proposes an optimal participation of reactive power of all devices available in the network. The propose approach is validated by comparing the results with other methods reported in the literature. The proposed method was implemented using Simulink of Matlab and OpenDSS. Optimization techniques and the presentation of results are from Matlab. The co-simulation of Electric Power Research Institute's (EPRI) OpenDSS program solves a three-phase optimal power flow problem in the unbalanced IEEE 13 and 34-node test feeders. The results from this work showed a better loss reduction compared to the Coordinated Voltage Control (CVC) method. The second method aims to minimize the voltage variation on the pilot bus on distribution network using DGs. It uses Pareto and Fuzzy-PID logic to reduce the voltage variation. Results indicate that the proposed method reduces the voltage variation more than the other methods. Simulink of Matlab and OpenDSS is used in the development of the proposed approach. The performance of the method is evaluated on IEEE 13-node test feeder with one and three DGs. Variables and unbalanced loads are used, based on real consumption data, over a time window of 48 hours. The third method aims to minimize the reactive losses using DGs on distribution networks. This method analyzes the problem using the IEEE 13-node test feeder with three different loads and the IEEE 123-node test feeder with four DGs. The DGs can be fixed or variables. Results indicate that integration of DGs to optimize the reactive power of the network helps to maintain the voltage within the allowed limits and to reduce the reactive power losses. The thesis is

  9. Automatic generation control of interconnected power system with ...

    African Journals Online (AJOL)

    In this paper, automatic generation control (AGC) of two area interconnected power system having diverse sources of power generation is studied. A two area power system comprises power generations from hydro, thermal and gas sources in area-1 and power generations from hydro and thermal sources in area-2. All the ...

  10. Automatic generation control of interconnected power system with ...

    African Journals Online (AJOL)

    user

    Abstract. In this paper, automatic generation control (AGC) of two area interconnected power system having diverse sources of power generation is studied. A two area power system comprises power generations from hydro, thermal and gas sources in area-1 and power generations from hydro and thermal sources in ...

  11. Augmented Reality Comes to Physics

    Science.gov (United States)

    Buesing, Mark; Cook, Michael

    2013-01-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as…

  12. Augmented reality

    Directory of Open Access Journals (Sweden)

    Patrik Pucer

    2011-08-01

    Full Text Available Today we can obtain in a simple and rapid way most of the information that we need. Devices, such as personal computers and mobile phones, enable access to information in different formats (written, pictorial, audio or video whenever and wherever. Daily we use and encounter information that can be seen as virtual objects or objects that are part of the virtual world of computers. Everyone, at least once, wanted to bring these virtual objects from the virtual world of computers into real environments and thus mix virtual and real worlds. In such a mixed reality, real and virtual objects coexist in the same environment. The reality, where users watch and use the real environment upgraded with virtual objects is called augmented reality. In this article we describe the main properties of augmented reality. In addition to the basic properties that define a reality as augmented reality, we present the various building elements (possible hardware and software that provide an insight into such a reality and practical applications of augmented reality. The applications are divided into three groups depending on the information and functions that augmented reality offers, such as help, guide and simulator.

  13. Modafinil augmentation therapy in unipolar and bipolar depression: a systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Goss, Alexander J; Kaser, Muzaffer; Costafreda, Sergi G; Sahakian, Barbara J; Fu, Cynthia H Y

    2013-11-01

    Current pharmacologic treatments for a depressive episode in unipolar major depressive disorder (MDD) and bipolar depression are limited by low rates of remission. Residual symptoms include a persistent low mood and neurovegetative symptoms such as fatigue. The objective of this study was to examine the efficacy and tolerability of augmentation of first-line therapies with the novel stimulant-like agent modafinil in MDD and bipolar depression. MEDLINE/PubMed, PsycINFO, 1980-April 2013 were searched using the following terms: (modafinil or armodafinil) and (depressi* or depressed or major depressive disorder or major depression or unipolar or bipolar or dysthymi*). Inclusion criteria were as follows: randomized controlled trial (RCT) design, sample comprising adult patients (18-65 years) with unipolar or bipolar depression, diagnosis according to DSM-IV, ICD-10, or other well-recognized criteria, modafinil or armodafinil given as augmentation therapy in at least 1 arm of the trial, and publication in English in a peer-reviewed journal. Double-blind, randomized, placebo-controlled clinical trials of adjunctive treatment with modafinil or armodafinil of standard treatment for depressive episodes in MDD and bipolar depression were selected. Two independent appraisers assessed the eligibility of the trials. A random-effects meta-analysis with DerSimonian-Laird method was used. Moderator effects were evaluated by meta-regression. Data from 6 RCTs, with a total of 910 patients with MDD or bipolar depression, consisting of 4 MDD RCTs (n = 568) and 2 bipolar depression RCTs (n = 342) were analyzed. The meta-analysis revealed significant effects of modafinil on improvements in overall depression scores (point estimate = -0.35; 95% CI, -0.61 to -0.10) and remission rates (odds ratio = 1.61; 95% CI, 1.04 to 2.49). The treatment effects were evident in both MDD and bipolar depression, with no difference between disorders. Modafinil showed a significant positive effect on

  14. A randomized controlled study of power posing before public speaking exposure for social anxiety disorder: No evidence for augmentative effects.

    Science.gov (United States)

    Davis, Michelle L; Papini, Santiago; Rosenfield, David; Roelofs, Karin; Kolb, Sarah; Powers, Mark B; Smits, Jasper A J

    2017-09-18

    This manuscript details a randomized controlled study designed to test the efficacy of power posing (i.e., briefly holding postures associated with dominance and power) as an augmentative strategy for exposure therapy for social anxiety disorder (SAD). Seventy-three individuals diagnosed with SAD were assigned to one of three conditions: power posing, submissive posing, or rest (no posing) prior to participating in an exposure therapy session. Participants were assessed for between-group differences in pre- and post-manipulation salivary hormone levels, within-session subjective experiences of fear, and pre- and 1-week post-treatment SAD severity outcome measures. Though the intervention resulted in decreased SAD symptom severity one week later, analyses revealed no significant between-group differences on any tested variables. Accordingly, this study provides no evidence to suggest that power posing impacts hormone levels or exposure therapy outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Vortex Generators to Control Boundary Layer Interactions

    Science.gov (United States)

    Babinsky, Holger (Inventor); Loth, Eric (Inventor); Lee, Sang (Inventor)

    2014-01-01

    Devices for generating streamwise vorticity in a boundary includes various forms of vortex generators. One form of a split-ramp vortex generator includes a first ramp element and a second ramp element with front ends and back ends, ramp surfaces extending between the front ends and the back ends, and vertical surfaces extending between the front ends and the back ends adjacent the ramp surfaces. A flow channel is between the first ramp element and the second ramp element. The back ends of the ramp elements have a height greater than a height of the front ends, and the front ends of the ramp elements have a width greater than a width of the back ends.

  16. Power Generation and Distribution via Distributed Coordination Control

    OpenAIRE

    Kim, Byeong-Yeon; Oh, Kwang-Kyo; Ahn, Hyo-Sung

    2014-01-01

    This paper presents power coordination, power generation, and power flow control schemes for supply-demand balance in distributed grid networks. Consensus schemes using only local information are employed to generate power coordination, power generation and power flow control signals. For the supply-demand balance, it is required to determine the amount of power needed at each distributed power node. Also due to the different power generation capacities of each power node, coordination of pow...

  17. The novel control method of switched reluctance generator

    Directory of Open Access Journals (Sweden)

    Bogusz Piotr

    2017-06-01

    Full Text Available In the paper, a novel control method of a switched reluctance generator was discussed. The presented control method allows a rotor rotating at high speed to enter the continuous-conduction mode which causes an increase of generated output power. A control function of the presented method was given as well as simulation and laboratory tests.

  18. Variable structure unit vector control of electric power generation ...

    African Journals Online (AJOL)

    A variable structure Automatic Generation Control (VSAGC) scheme is proposed in this paper for the control of a single area power system model dominated by steam powered electric generating plants. Unlike existing, VSAGC scheme where the selection of the control function is based on a trial and error procedure, the ...

  19. New generation control system at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Melen, R.

    1981-03-01

    The proposed SLAC Linear Collider (SLC) project will require an Instrumentation and Control system that provides integrated automatic monitoring and control functions. The present SLAC LINAC Instrumentation and Control system will be totally revamped and it will be expanded to include the support of all of the additional accelerator components that will be required for the whole SLC project. This paper describes the functional operation of the new system.

  20. Natural circulation steam generator model for optimal steam generator water level control

    Energy Technology Data Exchange (ETDEWEB)

    Feeley, J.J.

    1979-06-01

    Several authors have cited the control of steam generator water level as an important problem in the operation of pressurized water reactor plants. In this paper problems associated with steam generator water level control are identified, and advantages of modern estimation and control theory in dealing with these problems are discussed. A new state variable steam generator model and preliminary verification results using data from the loss of fluid test (LOFT) plant are also presented.

  1. [Augmented spontaneous breathing].

    Science.gov (United States)

    Hachenberg, T

    1996-09-01

    Impaired pulmonary gas exchange can result from lung parenchymal failure inducing oxygenation deficiency and fatigue of the respiratory muscles, which is characterized by hypercapnia or a combination of both mechanisms. Contractility of and coordination between the diaphragm and the thoracoabdominal respiratory muscles predominantly determine the efficiency of spontaneous breathing. Sepsis, cardiac failure, malnutrition or acute changes of the load conditions may induce fatigue of the respiratory muscles. Augmentation of spontaneous breathing is not only achieved by the application of different technical principles or devices; it also has to improve perfusion, metabolism, load conditions and contractility of the respiratory muscles. Intermittent mandatory ventilation (IMV) allows spontaneous breathing of the patient and augments alveolar ventilation by periodically applying positive airway pressure tidal volumes, which are generated by the respirator. Potential advantages include lower mean airway pressure (PAW), as compared with controlled mechanical ventilation, and improved haemodynamics. Suboptimal IMV systems may impose increased work and oxygen cost of breathing, fatigue of the respiratory muscles and CO2 retention. During pressure support ventilation (PSV), inspiratory alterations of PAW or gas flow (trigger) are detected by the respirator, which delivers a gas flow to maintain PAW at a fixed value (usually 5-20 cm H2O) during inspiration. PSV may be combined with other modalities of respiratory therapy such as IMV or CPAP. Claimed advantages of PSV include decreased effort of breathing, reduced systemic and respiratory muscle consumption of oxygen, prophylaxis of diaphragmatic fatigue and an improved extubation rate after prolonged periods of mechanical ventilation. Minimum alveolar ventilation is not guaranteed during PSV; thus, close observation of the patient is mandatory to avoid serious respiratory complications. Continuous positive airway pressure

  2. Engaging the CD40-CD40L pathway augments T-helper cell responses and improves control of Mycobacterium tuberculosis infection.

    Directory of Open Access Journals (Sweden)

    Jonathan Kevin Sia

    2017-08-01

    Full Text Available Mycobacterium tuberculosis (Mtb impairs dendritic cell (DC functions and induces suboptimal antigen-specific CD4 T cell immune responses that are poorly protective. Mucosal T-helper cells producing IFN-γ (Th1 and IL-17 (Th17 are important for protecting against tuberculosis (TB, but the mechanisms by which DCs generate antigen-specific T-helper responses during Mtb infection are not well defined. We previously reported that Mtb impairs CD40 expression on DCs and restricts Th1 and Th17 responses. We now demonstrate that CD40-dependent costimulation is required to generate IL-17 responses to Mtb. CD40-deficient DCs were unable to induce antigen-specific IL-17 responses after Mtb infection despite the production of Th17-polarizing innate cytokines. Disrupting the interaction between CD40 on DCs and its ligand CD40L on antigen-specific CD4 T cells, genetically or via antibody blockade, significantly reduced antigen-specific IL-17 responses. Importantly, engaging CD40 on DCs with a multimeric CD40 agonist (CD40LT enhanced antigen-specific IL-17 generation in ex vivo DC-T cell co-culture assays. Further, intratracheal instillation of Mtb-infected DCs treated with CD40LT significantly augmented antigen-specific Th17 responses in vivo in the lungs and lung-draining lymph nodes of mice. Finally, we show that boosting CD40-CD40L interactions promoted balanced Th1/Th17 responses in a setting of mucosal DC transfer, and conferred enhanced control of lung bacterial burdens following aerosol challenge with Mtb. Our results demonstrate that CD40 costimulation by DCs plays an important role in generating antigen-specific Th17 cells and targeting the CD40-CD40L pathway represents a novel strategy to improve adaptive immunity to TB.

  3. Rotational control of computer generated holograms.

    Science.gov (United States)

    Preece, Daryl; Rubinsztein-Dunlop, Halina

    2017-11-15

    We develop a basis for three-dimensional rotation of arbitrary light fields created by computer generated holograms. By adding an extra phase function into the kinoform, any light field or holographic image can be tilted in the focal plane with minimized distortion. We present two different approaches to rotate an arbitrary hologram: the Scheimpflug method and a novel coordinate transformation method. Experimental results are presented to demonstrate the validity of both proposed methods.

  4. Turbine Control of a Tidal and River Power Generator

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Wright, Alan; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-11-21

    As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded to include new types with promising future applications, such as river and tidal generation. The input variations to these types of resources are slower but also steadier than wind or solar generation. The level of water turbulent flow may vary from one place to another, however, the control algorithm can be adjusted to local environment. This paper describes the hydrokinetic aspects of river and tidal generation based on a river and tidal generator. Although the information given in this paper is not that of an exact generator deployed on site, the data used is representative of a typical river or tidal generator. In this paper, the hydrokinetic and associated electrical controller of the system were not included; however, the focus of this paper is on the hydrodynamic control.

  5. Turbine Control of a Tidal and River Power Generator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Gevorgian, Vahan; Wright, Alan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-08-01

    As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded to include new types with promising future applications, such as river and tidal generation. The input variations to these types of resources are slower but also steadier than wind or solar generation. The level of water turbulent flow may vary from one place to another, however, the control algorithm can be adjusted to local environment. This paper describes the hydrokinetic aspects of river and tidal generation based on a river and tidal generator. Although the information given in this paper is not that of an exact generator deployed on site, the data used is representative of a typical river or tidal generator. In this paper, the hydrokinetic and associated electrical controller of the system were not included; however, the focus of this paper is on the hydrodynamic control.

  6. Clinical Efficacy of Two Different Methods to Initiate Sensor-Augmented Insulin Pumps: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Jesus Moreno-Fernandez

    2016-01-01

    Full Text Available Aim. To analyze clinical effect of a novel approach to initiate sensor-augmented insulin pumps in type 1 diabetes mellitus (T1DM patients through early real-time continuous glucose monitoring (RT-CGM initiation. Methods. A 26-week pilot study with T1DM subjects randomized (1 : 1 to start RT-CGM three weeks before continuous subcutaneous insulin infusion (CGM pre-CSII or adding RT-CGM three weeks after continuous subcutaneous insulin infusion (CGM post-CSII. Results. Twenty-two patients were enrolled with a mean age of 36.6 yr. (range 19–59 yr. and T1DM duration of 16.8±10.6 yr. Higher adherence in CGM pre-CSII patients was confirmed at study end (84.6±11.1% versus 64.0±25.4%; P=0.01. The two intervention groups had similar HbA1c reduction at study end of −0.6% (P=0.9. Hypoglycemic event frequency reduction was observed from baseline to study end only in CGM pre-CSII group (mean difference in change, −6.3%; 95% confidence interval, −12.0 to −0.5; P=0.04. Moreover, no severe hypoglycemia was detected among CGM pre-CSII subjects during the study follow-up (0.0±0.0 events versus 0.63±1.0 events; P=0.03. CGM pre-CSII patients showed better satisfaction than CGM post-CSII patients at the end of the study (27.3±9.3 versus 32.9±7.2; P=0.04. Conclusions. CGM pre-CSII is a novel approach to improve glycemic control and satisfaction in type 1 diabetes sensor-augmented pump treated patients.

  7. Next Generation Network Routing and Control Plane

    DEFF Research Database (Denmark)

    Fu, Rong

    proved, the dominating Border Gateway Protocol (BGP) cannot address all the issues that in inter-domain QoS routing. Thus a new protocol or network architecture has to be developed to be able to carry the inter-domain traffic with the QoS and TE consideration. Moreover, the current network control also......-domain. It is a routing component that flexibly supports path computation with different requirements, constraints and areas. It is also can be seen as part of NGN transport control plane, which integrates with the other functions. In the aspect of resource control, an NGN release Resource and Admission Control Functions...... of Service classes. Under the NGN context, there are plenty of proposals intending to accommodate the issues listed above. Path Computation Elements (PCE) proposed by IETF designs suitable network architecture that aiming at compute the QoS based paths for traffic transportation through intra- and inter...

  8. Augmented Reality

    DEFF Research Database (Denmark)

    Nielsen, Birgitte Lund; Brandt, Harald; Radmer, Ole

    2017-01-01

    Artiklen præsenterer resultater fra pilotafprøvning i 7.-klasses fysik/kemi og biologi af to Augmented Reality (AR)-apps til naturfagsundervisning. Muligheder og udfordringer ved lærerens stilladsering af elevernes undersøgende samtale og modelleringskompetence er undersøgt med interview...

  9. Closed-Loop Hybrid Gaze Brain-Machine Interface Based Robotic Arm Control with Augmented Reality Feedback

    Directory of Open Access Journals (Sweden)

    Hong Zeng

    2017-10-01

    Full Text Available Brain-machine interface (BMI can be used to control the robotic arm to assist paralysis people for performing activities of daily living. However, it is still a complex task for the BMI users to control the process of objects grasping and lifting with the robotic arm. It is hard to achieve high efficiency and accuracy even after extensive trainings. One important reason is lacking of sufficient feedback information for the user to perform the closed-loop control. In this study, we proposed a method of augmented reality (AR guiding assistance to provide the enhanced visual feedback to the user for a closed-loop control with a hybrid Gaze-BMI, which combines the electroencephalography (EEG signals based BMI and the eye tracking for an intuitive and effective control of the robotic arm. Experiments for the objects manipulation tasks while avoiding the obstacle in the workspace are designed to evaluate the performance of our method for controlling the robotic arm. According to the experimental results obtained from eight subjects, the advantages of the proposed closed-loop system (with AR feedback over the open-loop system (with visual inspection only have been verified. The number of trigger commands used for controlling the robotic arm to grasp and lift the objects with AR feedback has reduced significantly and the height gaps of the gripper in the lifting process have decreased more than 50% compared to those trials with normal visual inspection only. The results reveal that the hybrid Gaze-BMI user can benefit from the information provided by the AR interface, improving the efficiency and reducing the cognitive load during the grasping and lifting processes.

  10. Closed-Loop Hybrid Gaze Brain-Machine Interface Based Robotic Arm Control with Augmented Reality Feedback.

    Science.gov (United States)

    Zeng, Hong; Wang, Yanxin; Wu, Changcheng; Song, Aiguo; Liu, Jia; Ji, Peng; Xu, Baoguo; Zhu, Lifeng; Li, Huijun; Wen, Pengcheng

    2017-01-01

    Brain-machine interface (BMI) can be used to control the robotic arm to assist paralysis people for performing activities of daily living. However, it is still a complex task for the BMI users to control the process of objects grasping and lifting with the robotic arm. It is hard to achieve high efficiency and accuracy even after extensive trainings. One important reason is lacking of sufficient feedback information for the user to perform the closed-loop control. In this study, we proposed a method of augmented reality (AR) guiding assistance to provide the enhanced visual feedback to the user for a closed-loop control with a hybrid Gaze-BMI, which combines the electroencephalography (EEG) signals based BMI and the eye tracking for an intuitive and effective control of the robotic arm. Experiments for the objects manipulation tasks while avoiding the obstacle in the workspace are designed to evaluate the performance of our method for controlling the robotic arm. According to the experimental results obtained from eight subjects, the advantages of the proposed closed-loop system (with AR feedback) over the open-loop system (with visual inspection only) have been verified. The number of trigger commands used for controlling the robotic arm to grasp and lift the objects with AR feedback has reduced significantly and the height gaps of the gripper in the lifting process have decreased more than 50% compared to those trials with normal visual inspection only. The results reveal that the hybrid Gaze-BMI user can benefit from the information provided by the AR interface, improving the efficiency and reducing the cognitive load during the grasping and lifting processes.

  11. A FESA Class Control Flow graph generator

    CERN Document Server

    Iliadi, Maria

    2015-01-01

    This report documents the work that was done during a summer student internship in the CERN BE-BI-SW group in the summer of 2015. The project proposal was to improve an existing tool for generating flowcharts from the design of a class and then create a GUI for the tool. The end result of the project is the improvement of the tool, so that the developer can have an overall image of the class’s design. Also, the GUI is functional at its current state and it can be extended with further work in order to be more user-friendly and offer more options to the user.

  12. Control strategy on the double-diffusive convection in a nanofluid layer with internal heat generation

    Science.gov (United States)

    Mokhtar, N. F. M.; Khalid, I. K.; Siri, Z.; Ibrahim, Z. B.; Gani, S. S. A.

    2017-10-01

    The influences of feedback control and internal heat source on the onset of Rayleigh-Bénard convection in a horizontal nanofluid layer is studied analytically due to Soret and Dufour parameters. The confining boundaries of the nanofluid layer (bottom boundary-top boundary) are assumed to be free-free, rigid-free, and rigid-rigid, with a source of heat from below. Linear stability theory is applied, and the eigenvalue solution is obtained numerically using the Galerkin technique. Focusing on the stationary convection, it is shown that there is a positive thermal resistance in the presence of feedback control on the onset of double-diffusive convection, while there is a positive thermal efficiency in the existence of internal heat generation. The possibilities of suppress or augment of the Rayleigh-Bénard convection in a nanofluid layer are also discussed in detail.

  13. Integrated control of next generation power system

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2010-02-28

    The multi-agent system (MAS) approach has been applied with promising results for enhancing an electric power distribution circuit, such as the Circuit of the Future as developed by Southern California Edison. These next generation power system results include better ability to reconfigure the circuit as well as the increased capability to improve the protection and enhance the reliability of the circuit. There were four main tasks in this project. The specific results for each of these four tasks and their related topics are presented in main sections of this report. Also, there were seven deliverables for this project. The main conclusions for these deliverables are summarized in the identified subtask section of this report. The specific details for each of these deliverables are included in the “Project Deliverables” section at the end of this Final Report.

  14. Hysteresis Control for a DC Connected Synchronous Generator

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg; Evangelos, Dimarakis

    2009-01-01

    Abstract— for offshore wind farms the distance to the coast increases, therefore DC cables will have to be used. For a variable speed wind turbine a rectifier and a synchronous generator with a boost converter is used. As a new suggestion for control the generator speed hysteresis control...

  15. Xenogeneic collagen matrix versus connective tissue graft for buccal soft tissue augmentation at implant site. A randomized, controlled clinical trial.

    Science.gov (United States)

    Cairo, Francesco; Barbato, Luigi; Tonelli, Paolo; Batalocco, Guido; Pagavino, Gabriella; Nieri, Michele

    2017-07-01

    Peri-implant soft tissue may be critical to prevent inflammation and promote gingival margin stability. The purpose of this randomized clinical trial (RCT) is to compare xenogeneic collagen matrix (XCM) versus connective tissue graft (CTG) to increase buccal soft tissue thickness at implant site. Soft tissue augmentation with XCM (test) or CTG (control) was performed at 60 implants in 60 patients at the time of implant uncovering. Measurements were performed by a blinded examiner at baseline, 3 and 6 months. Outcome measures included buccal soft tissue thickness (GT), apico-coronal keratinized tissue (KT), chair time and post-operative discomfort. Visual Analogue Scale (VAS) was used to evaluate patient satisfaction. After 6 months, the final GT increase was 0.9 ± 0.2 in the XCM group and 1.2 ± 0.3 mm in the CTG group, with a significant difference favouring the control group (0.3 mm; p = .0001). Both procedures resulted in similar final KT amount with no significant difference between treatments. XCM was associated with significant less chair-time (p tissue thickness. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. A culture of striving augments use of working memory? Implications for attention control.

    Science.gov (United States)

    Buszard, Tim; Masters, Rich S W

    2017-01-01

    A culture of striving was notable in the developmental background of many of the elite and super elite athletes in the Hardy et al. Critically, a culture of striving was credited with a positive influence on a range of issues relevant to elite sports performance, including performance under pressure. Of the six athletes who did not reveal a culture of striving, five reported the greatest difficulty performing in high-pressure situations. We suspect that a culture of striving facilitates the development of attention control ability, which subsequently assists performance under pressure. We discuss attention control from the perspective of working memory and hypothesize that a culture of striving trains individuals to maximize their working memory capacity. © 2017 Elsevier B.V. All rights reserved.

  17. Organelle size control - increasing vacuole content activates SNAREs to augment organelle volume through homotypic fusion.

    Science.gov (United States)

    Desfougères, Yann; Neumann, Heinz; Mayer, Andreas

    2016-07-15

    Cells control the size of their compartments relative to cell volume, but there is also size control within each organelle. Yeast vacuoles neither burst nor do they collapse into a ruffled morphology, indicating that the volume of the organellar envelope is adjusted to the amount of content. It is poorly understood how this adjustment is achieved. We show that the accumulating content of yeast vacuoles activates fusion of other vacuoles, thus increasing the volume-to-surface ratio. Synthesis of the dominant compound stored inside vacuoles, polyphosphate, stimulates binding of the chaperone Sec18/NSF to vacuolar SNAREs, which activates them and triggers fusion. SNAREs can only be activated by lumenal, not cytosolic, polyphosphate (polyP). Control of lumenal polyP over SNARE activation in the cytosol requires the cytosolic cyclin-dependent kinase Pho80-Pho85 and the R-SNARE Nyv1. These results suggest that cells can adapt the volume of vacuoles to their content through feedback from the vacuole lumen to the SNAREs on the cytosolic surface of the organelle. © 2016. Published by The Company of Biologists Ltd.

  18. Behavioral activation treatment for major depression: A randomized trial of the efficacy of augmentation with cognitive control training.

    Science.gov (United States)

    Moshier, Samantha J; Otto, Michael W

    2017-03-01

    Major depressive disorder (MDD) is associated with hypoactivation of the dorsolateral prefrontal cortex, a brain region involved in emotion regulation and basic cognitive control processes. Recent studies have indicated that computerized interventions designed to activate this region may reduce depressive and ruminative symptoms. In this double-blind randomized controlled trial, we tested whether one such program, called Cognitive Control Training (CCT), enhanced treatment outcomes when used in adjunct to brief behavior therapy for MDD. Thirty-four adults with MDD were randomly assigned to complete four sessions of either computerized CCT or a control task, concurrently with four sessions of Brief Behavioral Activation Therapy for Depression (BATD). Post-treatment and one-month follow-up assessments were conducted, with self-reported depressive symptoms as the primary outcome and clinician-rated depressive symptoms and self-reported rumination as secondary outcomes. In both intent-to-treat and completer analyses, depressive symptoms and rumination decreased significantly over the course of treatment in both treatment conditions. There were no significant differences in treatment outcome depending on the augmentation condition. The sample size was small, hindering secondary analyses and identification of potential predictors or moderators of treatment effect. Results demonstrate substantial clinical benefit following four sessions of BATD; however, adjunctive CCT did not enhance outcomes. This study and other recent research suggest that the effects of CCT may not be as robust as previously indicated, highlighting the need for continued investigation of the conditions under which CCT may be effective. Published by Elsevier B.V.

  19. Coaching to Augment Mentoring to Achieve Faculty Diversity: A Randomized Controlled Trial.

    Science.gov (United States)

    Williams, Simon N; Thakore, Bhoomi K; McGee, Richard

    2016-08-01

    The Academy for Future Science Faculty (the Academy) is a novel coaching intervention for biomedical PhD students designed to address limitations in previous efforts to promote faculty diversity. Unlike traditional research mentoring, the Academy includes both group and individual coaching, coaches have no research or evaluation roles with the students, and it is based on social science theories. The authors present a qualitative case study of one of the coaching groups and provide statistical analyses indicating whether one year in the Academy effects students' perceptions of the achievability and desirability of an academic career. The authors tested (July 2012-July 2013), with Northwestern University ethical approval, the Academy via a longitudinal randomized controlled trial. Participants were 121 latter-stage biomedical PhD students. The authors collected data via questionnaires, interviews, and meeting recordings. The case study shows how group career coaching can effectively supplement traditional one-to-one research mentoring; provide new role models for underrepresented minority students; and provide theory-based lenses through which to engage in open conversations about race, gender, and science careers. Repeated-measures analysis of variance showed that perceived achievability increased in the Academy group from baseline to one-year follow-up (mean, 5.75 versus 6.39) but decreased in the control group (6.58 versus 5.81). Perceived desirability decreased significantly less (P coaching model can effectively supplement traditional research mentoring and promote persistence toward academic careers.

  20. Histological and radiological evaluation of sintered and non-sintered deproteinized bovine bone substitute materials in sinus augmentation procedures. A prospective, randomized-controlled, clinical multicenter study.

    Science.gov (United States)

    Fienitz, Tim; Moses, Ofer; Klemm, Christoph; Happe, Arndt; Ferrari, Daniel; Kreppel, Matthias; Ormianer, Zeev; Gal, Moti; Rothamel, Daniel

    2017-04-01

    The objective of this study is to histologically and radiologically compare a sintered and a non-sintered bovine bone substitute material in sinus augmentation procedures. Thirty-three patients were included in the clinically controlled randomized multicentre study resulting in a total of 44 treated sinuses. After lateral approach, sinuses were filled with either a sintered (SBM, Alpha Bio's Graft(®)) or a non-sintered (NSBM, Bio Oss(®)) deproteinized bovine bone substitute material. The augmentation sites were radiologically assessed before and immediately after the augmentation procedure as well as prior to implant placement. Bone trephine biopsies for histological analysis were harvested 6 months after augmentation whilst preparing the osteotomies for implant placement. Healing was uneventful in all patients. After 6 months, radiological evaluation of 43 sinuses revealed a residual augmentation height of 94.65 % (±2.74) for SBM and 95.76 % (±2.15) for NSBM. One patient left the study for personal reasons. Histological analysis revealed a percentage of new bone of 29.71 % (±13.67) for SBM and 30.57 % (±16.07) for NSBM. Residual bone substitute material averaged at 40.68 % (±16.32) for SBM compared to 43.43 % (±19.07) for NSBM. All differences between the groups were not statistically significant (p > 0.05, Student's t test). Both xenogeneic bone substitute materials showed comparable results regarding new bone formation and radiological height changes in external sinus grafting procedures. Both bone substitute materials allow for a predictable new bone formation following sinus augmentation procedures.

  1. Control of large wind turbine generators connected to utility networks

    Science.gov (United States)

    Hinrichsen, E. N.

    1983-01-01

    This is an investigation of the control requirements for variable pitch wind turbine generators connected to electric power systems. The requirements include operation in very small as well as very large power systems. Control systems are developed for wind turbines with synchronous, induction, and doubly fed generators. Simulation results are presented. It is shown how wind turbines and power system controls can be integrated. A clear distinction is made between fast control of turbine torque, which is a peculiarity of wind turbines, and slow control of electric power, which is a traditional power system requirement.

  2. An Adaptive Multivariable Control System for Hydroelectric Generating Units

    Directory of Open Access Journals (Sweden)

    Gunne J. Hegglid

    1983-04-01

    Full Text Available This paper describes an adaptive multivariable control system for hydroelectric generating units. The system is based on a detailed mathematical model of the synchronous generator, the water turbine, the exiter system and turbine control servo. The models of the water penstock and the connected power system are static. These assumptions are not considered crucial. The system uses a Kalman filter for optimal estimation of the state variables and the parameters of the electric grid equivalent. The multivariable control law is computed from a Riccatti equation and is made adaptive to the generators running condition by means of a least square technique.

  3. Recommendations for volume augmentation and rejuvenation of the face and hands with the new generation polycaprolactone-based collagen stimulator (Ellansé®

    Directory of Open Access Journals (Sweden)

    de Melo F

    2017-11-01

    Full Text Available Francisco de Melo,1 Pierre Nicolau,2 Luca Piovano,3 Shang-Li Lin,4 Tiago Baptista-Fernandes,5 Martyn I King,6 Alessandra Camporese,7 Kyungkook Hong,8 Maria M Khattar,9 Marie-Odile Christen10 1Zo Skin Centre, Dubai, United Arab Emirates; 2Clinica Dr P Nicolau, Figueres (Girona, Spain; 3Piovano Medical Center, Roma, Italy; 4Shang-Li Dermatologic & Aesthetic Clinic, New Taipei City, Taiwan, Republic of China; 5Instituto Portugues de Crurgia Plastica, Lisboa, Portugal; 6Cosmedic Skin Clinic, Tamworth, Staffordshire, UK; 7Studio Medico, Cadoneghe Padova, Italy; 8Hus-hu Dermatology Clinic, Seoul, South Korea; 9Aesthetica Clinic, Dubai, United Arab Emirates; 10Behavior, Paris, France Background: The range of fillers currently available for soft-tissue augmentation is constantly expanding. The latest advances in filler technology include collagen biostimulators that exert their esthetic effect by promoting neocollagenesis. One such product is the next-generation collagen biostimulator (Ellansé® that demonstrates properties as yet unseen in soft-tissue fillers. It is composed of polycaprolactone (PCL microspheres in an aqueous carboxymethylcellulose gel carrier. Given its specific characteristics and the number of areas that can be treated with this innovative product, experts’ recommendations were deemed necessary and are therefore presented in this paper with a specific focus on the indications, treatment areas and procedures as well as injection techniques. Methods: A multinational, multidisciplinary group of plastic surgeons and dermatologists convened to develop recommendations with a worldwide perspective. This publication provides information on the specific characteristics of the product and focuses on the recommendations on the injection techniques. Results: Recommendations on injection techniques are provided for the upper face, mid-face and lower face and zone by zone for each of these areas, as well as hands. Based on the particular

  4. Exercise augmentation compared with usual care for post-traumatic stress disorder: a randomized controlled trial.

    Science.gov (United States)

    Rosenbaum, S; Sherrington, C; Tiedemann, A

    2015-05-01

    To investigate the impact of a 12-week exercise programme in addition to usual care for post-traumatic stress disorder (PTSD). An assessor-blinded randomized controlled trial was conducted among 81 participants with a DSM-IV-TR diagnosis of primary PTSD. Participants were recruited after admission to an in-patient programme at a private hospital. Participants were randomized to receive either usual care (n=42), or exercise in addition to usual care (n=39). The exercise intervention involved three, 30-min resistance-training sessions/week and a pedometer-based walking programme. Usual care involved psychotherapy, pharmaceutical interventions, and group therapy. Primary outcome was PTSD symptoms assessed via the PTSD checklist-civilian version (PCL-C). Secondary outcomes included symptoms of depression, anthropometry, physical activity, mobility, strength, and sleep quality. Participants had a mean (SD) age of 47.8 years (12.1), 84% male. PTSD symptoms in the intervention group significantly reduced compared with the usual care group (mean difference=-5.4, 95% CI -10.5 to -0.3, P=0.04, n=58). There were significant between-group differences at follow-up for depressive symptoms, waist circumference, sleep quality, and sedentary time. This study provides the first evidence that an exercise intervention is associated with reduced PTSD and depressive symptoms, reduced waist circumference, and improved sleep quality. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Optimal Excitation Controller Design for Wind Turbine Generator

    Directory of Open Access Journals (Sweden)

    A. K. Boglou

    2011-01-01

    Full Text Available An optimal excitation controller design based on multirate-output controllers (MROCs having a multirate sampling mechanismwith different sampling period in each measured output of the system is presented. The proposed H∞ -control techniqueis applied to the discrete linear open-loop system model which represents a wind turbine generator supplying an infinite busthrough a transmission line.

  6. Valorisation of urban elements through 3D models generated from image matching point clouds and augmented reality visualization based in mobile platforms

    Science.gov (United States)

    Marques, Luís.; Roca Cladera, Josep; Tenedório, José António

    2017-10-01

    The use of multiple sets of images with high level of overlapping to extract 3D point clouds has increased progressively in recent years. There are two main fundamental factors in the origin of this progress. In first, the image matching algorithms has been optimised and the software available that supports the progress of these techniques has been constantly developed. In second, because of the emergent paradigm of smart cities which has been promoting the virtualization of urban spaces and their elements. The creation of 3D models for urban elements is extremely relevant for urbanists to constitute digital archives of urban elements and being especially useful for enrich maps and databases or reconstruct and analyse objects/areas through time, building and recreating scenarios and implementing intuitive methods of interaction. These characteristics assist, for example, higher public participation creating a completely collaborative solution system, envisioning processes, simulations and results. This paper is organized in two main topics. The first deals with technical data modelling obtained by terrestrial photographs: planning criteria for obtaining photographs, approving or rejecting photos based on their quality, editing photos, creating masks, aligning photos, generating tie points, extracting point clouds, generating meshes, building textures and exporting results. The application of these procedures results in 3D models for the visualization of urban elements of the city of Barcelona. The second concerns the use of Augmented Reality through mobile platforms allowing to understand the city origins and the relation with the actual city morphology, (en)visioning solutions, processes and simulations, making possible for the agents in several domains, to fundament their decisions (and understand them) achieving a faster and wider consensus.

  7. Smart pitch control strategy for wind generation system using doubly fed induction generator

    Science.gov (United States)

    Raza, Syed Ahmed

    A smart pitch control strategy for a variable speed doubly fed wind generation system is presented in this thesis. A complete dynamic model of DFIG system is developed. The model consists of the generator, wind turbine, aerodynamic and the converter system. The strategy proposed includes the use of adaptive neural network to generate optimized controller gains for pitch control. This involves the generation of controller parameters of pitch controller making use of differential evolution intelligent technique. Training of the back propagation neural network has been carried out for the development of an adaptive neural network. This tunes the weights of the network according to the system states in a variable wind speed environment. Four cases have been taken to test the pitch controller which includes step and sinusoidal changes in wind speeds. The step change is composed of both step up and step down changes in wind speeds. The last case makes use of scaled wind data collected from the wind turbine installed at King Fahd University beach front. Simulation studies show that the differential evolution based adaptive neural network is capable of generating the appropriate control to deliver the maximum possible aerodynamic power available from wind to the generator in an efficient manner by minimizing the transients.

  8. A Virtual Synchronous Generator Based Hierarchical Control Scheme of Distributed Generation Systems

    Directory of Open Access Journals (Sweden)

    Gang Yao

    2017-12-01

    Full Text Available Sustainable energy-based generation systems, such as photovoltaic and wind turbine generation systems, normally adopt inverters to connect to the grid. These power electronic interfaces possess the characteristics of small inertia and small output impedance, which create difficulties to stabilize the voltage and frequency of a distributed power source. To deal with this problem, a Virtual Synchronous Generator (VSG-based inverter control method is presented in this paper by introducing virtual inertia and damping coefficient into the control loop to emulate the dynamic behavior of a traditional synchronous generator. Based on this VSG control method, a three-layer hierarchical control scheme is further proposed to increase the control accuracy of the voltage and frequency in a VSG-based distributed generation system with parallel inverters. The principle of the VSG control method, the system stability analysis, the design process of the hierarchical control structure, and the frequency/voltage secondary regulation processes are all specified in this paper. Finally, some numerical simulations are carried out and the effectiveness of proposed control scheme is verified by the simulation results analysis.

  9. Doubly-Fed Induction Generator Control Under Voltage Sags

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede; Lima, K.

    2008-01-01

    This paper proposes a new control technique to improve the fault-ride through capability of doubly fed induction generators (DFIG). In such generators the appearance of severe voltage sags at the coupling point make rise to high over currents at the rotor/stator windings, something that makes...

  10. Development of smart controller model for dual fuel generator systems

    African Journals Online (AJOL)

    Application of dual fuel powered electric generators such as one of diesel and biogas has gained popularity locally both as emergency power supply units and in distributed power systems. Dual fuel generators use two fuel types simultaneously in their operations. This is however faced with challenges in control and fuel ...

  11. Model Oriented Application Generation for Industrial Control Systems

    CERN Document Server

    Copy, B; Blanco Vinuela, E; Fernandez Adiego, B; Nogueira Ferandes, R; Prieto Barreiro, I

    2011-01-01

    The CERN Unified Industrial Control Systems framework (UNICOS) is a software generation methodology and a collection of development tools that standardizes the design of industrial control applications [1]. A Software Factory, named the UNICOS Application Builder (UAB) [2], was introduced to ease extensibility and maintenance of the framework, introducing a stable metamodel, a set of platformindependent models and platformspecific configurations against which code generation plugins and configuration generation plugins can be written. Such plugins currently target PLC programming environments (Schneider and SIEMENS PLCs) as well as SIEMENS WinCC Open Architecture SCADA (previously known as ETM PVSS) but are being expanded to cover more and more aspects of process control systems. We present what constitutes the UNICOS metamodel and the models in use, how these models can be used to capture knowledge about industrial control systems and how this knowledge can be leveraged to generate both code and configuratio...

  12. Mobile Collaborative Augmented Reality: The Augmented Stroll

    OpenAIRE

    Renevier, Philippe; Nigay, Laurence

    2001-01-01

    International audience; The paper focuses on Augmented Reality systems in which interaction with the real world is augmented by the computer, the task being performed in the real world. We first define what mobile AR systems, collaborative AR systems and finally mobile and collaborative AR systems are. We then present the augmented stroll and its software design as one example of a mobile and collaborative AR system. The augmented stroll is applied to Archaeology in the MAGIC (Mobile Augmente...

  13. Robust controller for synchronous generator with local load via VSC

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Vazquez, J. [Universidad de Guadalajara, Centro Universitario de Ciencias Exactas e Ingenierias, Departamento de Electronica, Av. Revolucion No. 1500, Modulo ' ' O' ' , Apdo. Postal 44840, Guadalajara Jalisco (Mexico); Loukianov, Alexander G.; Canedo, Jose M. [Centro de Investigacion y de Estudios Avanzados del IPN, Apdo. Postal 31-438, Plaza La Luna, C. P. 44550, Guadalajara, Jalisco (Mexico); Utkin, Vadim I. [Department of Electrical Engineering, The Ohio-State University, Columbus, OH 43210-1272 (United States)

    2007-05-15

    The objective of this paper is to design a nonlinear observer-based excitation controller for power system comprising a single synchronous generator connected to an infinite bus with local load. The controller proposed is based on the using first singular perturbation systems concepts and then Sliding Mode Control technique combining with Block Control Principle. To reduce ''chattering'' a nonlinear observer with estimation of the mechanical torque and rotor fluxes is designed. This combined approach enables to compensate the inherent nonlinearities of the generator and to reject external disturbances. (author)

  14. Coordinate generation with precise controls over mesh properties

    Science.gov (United States)

    Eiseman, P. R.

    1982-01-01

    Powerful local controls have been developed for mesh generation with the class of multisurface coordinate transformations. The controls come from local piecewise linear interpolants, and the resulting coordinates have continuous first derivatives. At the boundaries, the mesh controls provide the capability of joining distinct coordinate systems together with continuous derivatives. Away from boundaries, a local region can be given a particular mesh form to model internal objects or to simplify a problem. Applications of the controls are illustrated with a sequence of two-dimensional examples. For simplicity, each is generated about a NACA0012 airfoil which is of unit length and with leading edge pointed in a negative x-direction.

  15. Augmented Reality Comes to Physics

    Science.gov (United States)

    Buesing, Mark; Cook, Michael

    2013-04-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

  16. Towards Intelligent Control for Next Generation CESTOL Aircraft

    Science.gov (United States)

    Acosta, Diana Michelle

    2008-01-01

    This talk will present the motivation, research approach and status of intelligent control research for Next Generation Cruise Efficient Short Take Off and Landing (CESTOL) aircraft. An introduction to the challenges of CESTOL control will be given, leading into an assessment of potential control solutions. The approach of the control research will be discussed, including a brief overview of the technical aspects of the research.

  17. Next generation discharge control system for ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Raupp, G.; Behler, K. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Cole, R.; Lueddecke, K. [Unlimited Computer Systems, Neuried (Germany); Mertens, V.; Neu, G.; Treutterer, W.; Zasche, D.; Zehetbauer, T. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748, Garching bei Muenchen (Germany)

    1999-11-01

    Based on present achievements in tokamak control and considering requirements for reactor-oriented research, a next generation discharge control system is presented. Decomposition of control functions mapped onto dedicated controllers and diagnostics gives a distributed system integrated with a common real-time network to publish process and reference values. Basic mechanisms for cycle administration, data exchange and process management of the prototype system currently being implemented are shown. (orig.)

  18. Fractional order fuzzy control of hybrid power system with renewable generation using chaotic PSO.

    Science.gov (United States)

    Pan, Indranil; Das, Saptarshi

    2016-05-01

    This paper investigates the operation of a hybrid power system through a novel fuzzy control scheme. The hybrid power system employs various autonomous generation systems like wind turbine, solar photovoltaic, diesel engine, fuel-cell, aqua electrolyzer etc. Other energy storage devices like the battery, flywheel and ultra-capacitor are also present in the network. A novel fractional order (FO) fuzzy control scheme is employed and its parameters are tuned with a particle swarm optimization (PSO) algorithm augmented with two chaotic maps for achieving an improved performance. This FO fuzzy controller shows better performance over the classical PID, and the integer order fuzzy PID controller in both linear and nonlinear operating regimes. The FO fuzzy controller also shows stronger robustness properties against system parameter variation and rate constraint nonlinearity, than that with the other controller structures. The robustness is a highly desirable property in such a scenario since many components of the hybrid power system may be switched on/off or may run at lower/higher power output, at different time instants. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Automatic control system generation for robot design validation

    Science.gov (United States)

    Bacon, James A. (Inventor); English, James D. (Inventor)

    2012-01-01

    The specification and drawings present a new method, system and software product for and apparatus for generating a robotic validation system for a robot design. The robotic validation system for the robot design of a robotic system is automatically generated by converting a robot design into a generic robotic description using a predetermined format, then generating a control system from the generic robotic description and finally updating robot design parameters of the robotic system with an analysis tool using both the generic robot description and the control system.

  20. Augmented reality telementoring (ART) platform: a randomized controlled trial to assess the efficacy of a new surgical education technology.

    Science.gov (United States)

    Vera, Angelina M; Russo, Michael; Mohsin, Adnan; Tsuda, Shawn

    2014-12-01

    Laparoscopic skills training has evolved over recent years. However, conveying a mentor's directions using conventional methods, without realistic on-screen visual cues, can be difficult and confusing. To facilitate laparoscopic skill transference, an augmented reality telementoring (ART) platform was designed to overlay the instruments of a mentor onto the trainee's laparoscopic monitor. The aim of this study was to compare the effectiveness of this new teaching modality to traditional methods in novices performing an intracorporeal suturing task. Nineteen pre-medical and medical students were randomized into traditional mentoring (n = 9) and ART (n = 10) groups for a laparoscopic suturing and knot-tying task. Subjects received either traditional mentoring or ART for 1 h on the validated fundamentals of laparoscopic surgery intracorporeal suturing task. Tasks for suturing were recorded and scored for time and errors. Results were analyzed using means, standard deviation, power regression analysis, correlation coefficient, analysis of variance, and student's t test. Using Wright's cumulative average model (Y = aX (b)) the learning curve slope was significantly steeper, demonstrating faster skill acquisition, for the ART group (b = -0.567, r (2) = 0.92) than the control group (b = -0.453, r (2) = 0.74). At the end of 10 repetitions or 1 h of practice, the ART group was faster versus traditional (mean 167.4 vs. 242.4 s, p = 0.014). The ART group also had fewer fails (8) than the traditional group (13). The ART Platform may be a more effective training technique in teaching laparoscopic skills to novices compared to traditional methods. ART conferred a shorter learning curve, which was more pronounced in the first 4 trials. ART reduced the number of failed attempts and resulted in faster suture times by the end of the training session. ART may be a more effective training tool in laparoscopic surgical training for complex tasks than traditional methods.

  1. Control-Oriented Model of a Generating Set Comprising a Diesel Engine and a Synchronous Generator

    Directory of Open Access Journals (Sweden)

    Mutaz Tuffaha

    2015-10-01

    Full Text Available A generating set (Genset comprises a prime mover such as a Diesel Engine, and a synchronous generator. The most important controllers of such systems are the speed governor to regulate the engine or shaft speed and the automatic voltage regulator (AVR to regulate the terminal voltage. The speed governor is a PID controller that uses the difference between the speed and its desired value as a feedback signal to change the fuel mass input by changing the fuel rack position. AVR is also a PID that uses the difference between the terminal voltage of the generator and its desired value, and changes it by manipulating the voltage of the field excitation circuit. Thus, the two controllers act separately. That is to say, if the speed varies from the desired value, the speed governor will react, while the AVR will not react as long as the voltage is stable, and vice versa. In this work, a control-oriented model is suggested for a Genset, and then a controller, that regulates the shaft speed and the terminal voltage, is designed by feedback linearisation. The proposed controller has two inputs: the fuel mass and the field circuit voltage. Simulations show that the proposed controller makes the two inputs act, simultaneously. Thus, any change of the speed e.g., forces the two input controls to react, in contrast to the ordinary PID controllers. Further, we discuss the robustness of the proposed controller to uncertainties and time delay.

  2. Design of fault tolerant control system for steam generator using

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Ki; Seo, Mi Ro [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A controller and sensor fault tolerant system for a steam generator is designed with fuzzy logic. A structure of the proposed fault tolerant redundant system is composed of a supervisor and two fuzzy weighting modulators. A supervisor alternatively checks a controller and a sensor induced performances to identify which part, a controller or a sensor, is faulty. In order to analyze controller induced performance both an error and a change in error of the system output are chosen as fuzzy variables. The fuzzy logic for a sensor induced performance uses two variables : a deviation between two sensor outputs and its frequency. Fuzzy weighting modulator generates an output signal compensated for faulty input signal. Simulations show that the proposed fault tolerant control scheme for a steam generator regulates well water level by suppressing fault effect of either controllers or sensors. Therefore through duplicating sensors and controllers with the proposed fault tolerant scheme, both a reliability of a steam generator control and sensor system and that of a power plant increase even more. 2 refs., 9 figs., 1 tab. (Author)

  3. Controlling Virtual Clouds and Making it Rain Particle Systems in Real Spaces Using Situated Augmented Simulation and Portable Virtual Environments

    Science.gov (United States)

    Hedley, N.; Lonergan, C. D.

    2012-07-01

    The research described in this paper reports on the design, rationale, development and implementation of a set of new geospatial interfaces that combine multi-touch interaction, portable virtual environments, 'geosimulation gaming', and mobile augmented reality. The result is a set of new ways for us to combine the capabilities of geospatial virtual environments, augmented realitiy and geosimulation. These new hybrid interfaces deliver new geospatial information experiences - new ways of connecting spatial data, simulations, and abstract concepts to real spaces. Their potential to enhance environmental perception and learning must be explored.

  4. CONTROLLING VIRTUAL CLOUDS AND MAKING IT RAIN PARTICLE SYSTEMS IN REAL SPACES USING SITUATED AUGMENTED SIMULATION AND PORTABLE VIRTUAL ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    N. Hedley

    2012-07-01

    Full Text Available The research described in this paper reports on the design, rationale, development and implementation of a set of new geospatial interfaces that combine multi-touch interaction, portable virtual environments, 'geosimulation gaming', and mobile augmented reality. The result is a set of new ways for us to combine the capabilities of geospatial virtual environments, augmented realitiy and geosimulation. These new hybrid interfaces deliver new geospatial information experiences – new ways of connecting spatial data, simulations, and abstract concepts to real spaces. Their potential to enhance environmental perception and learning must be explored.

  5. Dynamic modeling, simulation and control of energy generation

    CERN Document Server

    Vepa, Ranjan

    2013-01-01

    This book addresses the core issues involved in the dynamic modeling, simulation and control of a selection of energy systems such as gas turbines, wind turbines, fuel cells and batteries. The principles of modeling and control could be applied to other non-convention methods of energy generation such as solar energy and wave energy.A central feature of Dynamic Modeling, Simulation and Control of Energy Generation is that it brings together diverse topics in thermodynamics, fluid mechanics, heat transfer, electro-chemistry, electrical networks and electrical machines and focuses on their appli

  6. Exercise augmentation compared to usual care for Post Traumatic Stress Disorder: A Randomised Controlled Trial (The REAP study: Randomised Exercise Augmentation for PTSD

    Directory of Open Access Journals (Sweden)

    van der Ploeg Hidde P

    2011-07-01

    Full Text Available Abstract Background The physical wellbeing of people with mental health conditions can often be overlooked in order to treat the primary mental health condition as a priority. Exercise however, can potentially improve both the primary psychiatric condition as well as physical measures that indicate risk of other conditions such as diabetes mellitus and cardiovascular disease. Evidence supports the role of exercise as an important component of treatment for depression and anxiety, yet no randomised controlled trials (RCT's have been conducted to evaluate the use of exercise in the treatment of people with post traumatic stress disorder (PTSD. This RCT will investigate the effects of structured, progressive exercise on PTSD symptoms, functional ability, body composition, physical activity levels, sleep patterns and medication usage. Methods and design Eighty participants with a Diagnostic and Statistical Manual of Mental Disorders (DSM-IV diagnosis of PTSD will be recruited. Participants will have no contraindications to exercise and will be cognitively able to provide consent to participate in the study. The primary outcome measures will be PTSD symptoms, measured through the PTSD Checklist Civilian (PCL-C scale. Secondary outcome measures will assess depression and anxiety, mobility and strength, body composition, physical activity levels, sleep patterns and medication usage. All outcomes will be assessed by a health or exercise professional masked to group allocation at baseline and 12 weeks after randomisation. The intervention will be a 12 week individualised program, primarily involving resistance exercises with the use of exercise bands. A walking component will also be incorporated. Participants will complete one supervised session per week, and will be asked to perform at least two other non-supervised exercise sessions per week. Both intervention and control groups will receive all usual non-exercise interventions including psychotherapy

  7. The effect of augmentation of labour with syntocinon on the fetal CTG using objective computerised analysis: a nested case-control study.

    Science.gov (United States)

    Aye, C Y L; Redman, C W G; Georgieva, A

    2014-05-01

    To investigate the effect of syntocinon augmentation on the fetal cardiotocogram (CTG) using computerised analysis. We hypothesised that syntocinon will have no direct effects on the fetal heart rate if used correctly. A retrospective, nested case-control study. Intrapartum CTG records from the digital archive at the John Radcliffe Hospital, Oxford, UK. 110 women with singleton pregnancies of >36 weeks gestation, no known congenital abnormality, spontaneous onset of labour and syntocinon augmentation for failure to progress, with start time of syntocinon recorded, from between August 1998 and December 1999, extensively matched to 110 controls who had normally progressing labours. Eight different CTG features were measured during four time points with OxSys, a computerised numerical analysis system. Differences in the CTG features over time in cases and controls using ANOVA and Friedman's ANOVA and at each time point between case-control pairs using Student's t-test and the Wilcoxon signed rank test. After administration, syntocinon increased the frequency, decreased the duration and decreased the resting time between contractions (p<0.001), resulting in no significant difference between normally progressing labours and those requiring augmentation. The case group had a significantly higher signal stability index (SSI) and fewer decelerations compared to the control group - differences which disappeared after augmentation was commenced (p=0.025 and 0.033 respectively). Syntocinon did not affect the baseline heart rate, short term variability (STV) or phase rectified signal averaging (PRSA) (p=0.518, 0.215 and 0.138) in comparison with controls. There was a significant increase in the PRSA in babies born with acidaemia (arterial pH≤7.05) 60-120min after syntocinon was commenced that was not seen with in babies with a normal pH (p=0.002). Syntocinon "normalises" ineffective uterine activity without any direct effect on the fetal heart rate. Therefore its

  8. Evaluation of Current Controllers for Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Timbus, Adrian; Liserre, Marco; Teodorescu, Remus

    2009-01-01

    This paper discusses the evaluation of different current controllers employed for grid-connected distributed power generation systems having variable input power, such as wind turbines and photovoltaic systems. The focus is mainly set on linear controllers such as proportional......-integral, proportional-resonant, and deadbeat (DB) controllers. Additionally, an improved DB controller robust against grid impedance variation is also presented. Since the paper discusses the implementation of these controllers for grid-connected applications, their evaluation is made in three operating conditions...

  9. Group excitation control of generators in state regional electric power plant transformer station automatic control systems

    Energy Technology Data Exchange (ETDEWEB)

    Gumin, M.I.; Rosman, L.V.; Tarnavskii, V.M.

    1983-01-01

    Group excitation control of electric generators according to standard methods is essential for the management of power plant conditions according to voltage and reactive power. A system is described that provides coordinated changes in the automatic excitation controller set point for generators that operate on common buses. The advantages of the excitation control system are discussed.

  10. Efficacy of indigenous predatory mites (Acari: Phytoseiidae) against the citrus rust mite Phyllocoptruta oleivora (Acari: Eriophyidae): augmentation and conservation biological control in Israeli citrus orchards.

    Science.gov (United States)

    Maoz, Yonatan; Gal, Shira; Argov, Yael; Domeratzky, Sylvie; Melamed, Eti; Gan-Mor, Samuel; Coll, Moshe; Palevsky, Eric

    2014-07-01

    The citrus rust mite (CRM), Phyllocoptruta oleivora (Acari: Eriophyidae) is a cosmopolitan key pest of citrus, inflicting severe economic damage if not controlled. In Israel, CRM damages all citrus cultivars. International regulation and increasing control failures of CRM led growers to seek sustainable biological control solutions such as acarine biological control agents. Laboratory studies conducted in Israel have indicated that the indigenous predator species Amblyseius swirskii, Iphiseius degenerans, Typhlodromus athiasae and Euseius scutalis (all Acari: Phytoseiidae) can potentially control CRM. Our general objective in the present study was to bridge the gap of knowledge between laboratory studies and the lack of control efficacy of these species in commercial orchards. Predator augmentation in the field showed that although predator populations increased immediately following releases they later decreased and did not affect CRM populations. When A. swirskii augmentation was combined with a series of maize pollen applications, A. swirskii populations were enhanced substantially and continuously but again CRM populations were not affected. Growth chamber studies with CRM-infested seedlings, with or without a maize pollen supplement, indicated that pollen provisioning led to population increase of E. scutalis and A. swirskii but only E. scutalis significantly lowered CRM populations. Control with E. scutalis was confirmed in the field on CRM infested seedlings with pollen provisioned by adjacent flowering Rhodes grass. While experiments in mature citrus orchard showed that pollen supplement usually increased predator populations they also indicated that other factors such as intraguild interactions and pesticide treatments should be taken into account when devising CRM biological control programs.

  11. ARLearn: augmented reality meets augmented virtuality

    NARCIS (Netherlands)

    Ternier, Stefaan; Klemke, Roland; Kalz, Marco; Van Ulzen, Patricia; Specht, Marcus

    2012-01-01

    Ternier, S., Klemke, R., Kalz, M., Van Ulzen, P., & Specht, M. (2012). ARLearn: augmented reality meets augmented virtuality [Special issue]. Journal of Universal Computer Science - Technology for learning across physical and virtual spaces, 18(15), 2143-2164.

  12. Agent Based Control of Electric Power Systems with Distributed Generation

    DEFF Research Database (Denmark)

    Saleem, Arshad

    Distributed generation, decentralized and local control, self organization and autonomy are evident trends of today's electric power systems focusing on innovative control architectures such as MicroGrids, Virtual Power Plants, Cell based systems, plug-in electric vehicles and real time markets...... have been developed particularly in the area of communication and distributed control. Electric power industry is eager to explore, evaluate and adopt these new advancements in ICT for improving its current practices of automation and control in order to cope with above mentioned challenges....... This thesis focuses on making a systematic evaluation of using intelligent software agent technology for control of electric power systems with high penetration of distributed generation. The thesis is based upon a requirement driven approach. It starts with investigating new trends and challenges in Electric...

  13. Mathematical modeling of control system for the experimental steam generator

    Directory of Open Access Journals (Sweden)

    Podlasek Szymon

    2016-01-01

    Full Text Available A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units – quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

  14. Mathematical modeling of control system for the experimental steam generator

    Science.gov (United States)

    Podlasek, Szymon; Lalik, Krzysztof; Filipowicz, Mariusz; Sornek, Krzysztof; Kupski, Robert; Raś, Anita

    2016-03-01

    A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units - quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics) are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

  15. Sagnac Interferometer Based Generation of Controllable Cylindrical Vector Beams

    Directory of Open Access Journals (Sweden)

    Cristian Acevedo

    2016-01-01

    Full Text Available We report on a novel experimental geometry to generate cylindrical vector beams in a very robust manner. Continuous control of beams’ properties is obtained using an optically addressable spatial light modulator incorporated into a Sagnac interferometer. Forked computer-generated holograms allow introducing different topological charges while orthogonally polarized beams within the interferometer permit encoding the spatial distribution of polarization. We also demonstrate the generation of complex waveforms obtained by combining two orthogonal beams having both radial modulations and azimuthal dislocations.

  16. Next Generation Nuclear Plant Resilient Control System Functional Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lynne M. Stevens

    2010-07-01

    Control Systems and their associated instrumentation must meet reliability, availability, maintainability, and resiliency criteria in order for high temperature gas-cooled reactors (HTGRs) to be economically competitive. Research, perhaps requiring several years, may be needed to develop control systems to support plant availability and resiliency. This report functionally analyzes the gaps between traditional and resilient control systems as applicable to HTGRs, which includes the Next Generation Nuclear Plant; defines resilient controls; assesses the current state of both traditional and resilient control systems; and documents the functional gaps existing between these two controls approaches as applicable to HTGRs. This report supports the development of an overall strategy for applying resilient controls to HTGRs by showing that control systems with adequate levels of resilience perform at higher levels, respond more quickly to disturbances, increase operational efficiency, and increase public protection.

  17. Torque-stiffness-controlled dynamic walking with central pattern generators.

    Science.gov (United States)

    Huang, Yan; Vanderborght, Bram; Van Ham, Ronald; Wang, Qining

    2014-12-01

    Walking behavior is modulated by controlling joint torques in most existing passivity-based bipeds. Controlled Passive Walking with adaptable stiffness exhibits controllable natural motions and energy efficient gaits. In this paper, we propose torque-stiffness-controlled dynamic bipedal walking, which extends the concept of Controlled Passive Walking by introducing structured control parameters and a bio-inspired control method with central pattern generators. The proposed walking paradigm is beneficial in clarifying the respective effects of the external actuation and the internal natural dynamics. We present a seven-link biped model to validate the presented walking. Effects of joint torque and joint stiffness on gait selection, walking performance and walking pattern transitions are studied in simulations. The work in this paper develops a new solution of motion control of bipedal robots with adaptable stiffness and provides insights of efficient and sophisticated walking gaits of humans.

  18. Experimental comparison of PV-smoothing controllers using distributed generators

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean; Ellis, Abraham; Denda, Atsushi; Morino, Kimio; Hawkins, John N.; Arellano, Brian; Shinji, Takao; Ogata, Takao; Tadokoro, Masayuki

    2014-02-01

    The power output variability of photovoltaic systems can affect local electrical grids in locations with high renewable energy penetrations or weak distribution or transmission systems. In those rare cases, quick controllable generators (e.g., energy storage systems) or loads can counteract the destabilizing effects by compensating for the power fluctuations. Previously, control algorithms for coordinated and uncoordinated operation of a small natural gas engine-generator (genset) and a battery for smoothing PV plant output were optimized using MATLAB/Simulink simulations. The simulations demonstrated that a traditional generation resource such as a natural gas genset in combination with a battery would smooth the photovoltaic output while using a smaller battery state of charge (SOC) range and extending the life of the battery. This paper reports on the experimental implementation of the coordinated and uncoordinated controllers to verify the simulations and determine the differences in the controllers. The experiments were performed with the PNM PV and energy storage Prosperity site and a gas engine-generator located at the Aperture Center at Mesa Del Sol in Albuquerque, New Mexico. Two field demonstrations were performed to compare the different PV smoothing control algorithms: (1) implementing the coordinated and uncoordinated controls while switching off a subsection of the PV array at precise times on successive clear days, and (2) comparing the results of the battery and genset outputs for the coordinated control on a high variability day with simulations of the coordinated and uncoordinated controls. It was found that for certain PV power profiles the SOC range of the battery may be larger with the coordinated control, but the total amp-hours through the battery-which approximates battery wear-will always be smaller with the coordinated control.

  19. Adherence to AHA Guidelines When Adapted for Augmented Reality Glasses for Assisted Pediatric Cardiopulmonary Resuscitation: A Randomized Controlled Trial.

    Science.gov (United States)

    Siebert, Johan N; Ehrler, Frederic; Gervaix, Alain; Haddad, Kevin; Lacroix, Laurence; Schrurs, Philippe; Sahin, Ayhan; Lovis, Christian; Manzano, Sergio

    2017-05-29

    The American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) are nowadays recognized as the world's most authoritative resuscitation guidelines. Adherence to these guidelines optimizes the management of critically ill patients and increases their chances of survival after cardiac arrest. Despite their availability, suboptimal quality of CPR is still common. Currently, the median hospital survival rate after pediatric in-hospital cardiac arrest is 36%, whereas it falls below 10% for out-of-hospital cardiac arrest. Among emerging information technologies and devices able to support caregivers during resuscitation and increase adherence to AHA guidelines, augmented reality (AR) glasses have not yet been assessed. In order to assess their potential, we adapted AHA Pediatric Advanced Life Support (PALS) guidelines for AR glasses. The study aimed to determine whether adapting AHA guidelines for AR glasses increased adherence by reducing deviation and time to initiation of critical life-saving maneuvers during pediatric CPR when compared with the use of PALS pocket reference cards. We conducted a randomized controlled trial with two parallel groups of voluntary pediatric residents, comparing AR glasses to PALS pocket reference cards during a simulation-based pediatric cardiac arrest scenario-pulseless ventricular tachycardia (pVT). The primary outcome was the elapsed time in seconds in each allocation group, from onset of pVT to the first defibrillation attempt. Secondary outcomes were time elapsed to (1) initiation of chest compression, (2) subsequent defibrillation attempts, and (3) administration of drugs, as well as the time intervals between defibrillation attempts and drug doses, shock doses, and number of shocks. All these outcomes were assessed for deviation from AHA guidelines. Twenty residents were randomized into 2 groups. Time to first defibrillation attempt (mean: 146 s) and adherence to AHA guidelines in terms of time to other

  20. Quadratic controller syntheses for the steam generator water level

    Energy Technology Data Exchange (ETDEWEB)

    Arzelier, D.; Daafouz, J.; Bernussou, J.; Garcia, G

    1998-06-01

    The steam generator water level, (SGWL), control problem in the pressurized water reactor of a nuclear power plant is considered from robust control techniques point of view. The plant is a time-varying system with a non minimum phase behavior and an unstable open-loop response. The time-varying nature of the plant due to change in operating power is taken into account by including slowly time-varying uncertainty in the model. A linear Time-Invariant, (LTI) guaranteed cost quadratic stabilizing controller is designed in order to address some of the particular issues arising for such a control problem. (author) 17 refs.

  1. Adaptive neuro-fuzzy inference system based automatic generation control

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, S.H.; Etemadi, A.H. [Department of Electrical Engineering, Sharif University of Technology, Tehran (Iran)

    2008-07-15

    Fixed gain controllers for automatic generation control are designed at nominal operating conditions and fail to provide best control performance over a wide range of operating conditions. So, to keep system performance near its optimum, it is desirable to track the operating conditions and use updated parameters to compute control gains. A control scheme based on artificial neuro-fuzzy inference system (ANFIS), which is trained by the results of off-line studies obtained using particle swarm optimization, is proposed in this paper to optimize and update control gains in real-time according to load variations. Also, frequency relaxation is implemented using ANFIS. The efficiency of the proposed method is demonstrated via simulations. Compliance of the proposed method with NERC control performance standard is verified. (author)

  2. Intelligent control of diesel generators using gain-scheduling

    DEFF Research Database (Denmark)

    Mai, Christian; Jepsen, Kasper; Yang, Zhenyu

    2014-01-01

    The development of an intelligent control solution for a wide range of diesel generators is discussed. Compared with most existing solutions, the advantages of the proposed solution lie in two folds: (i) The proposed control has the plug-and-play capability which is reflected by an automatic reco...... a controlled AC-motor is employed to emulate a diesel engine. The testing results clearly show that the proposed control solution can lead to a better overall system performance than most existing solutions do, especially subject to widely diverse operating conditions...... keep a consistent performance for a wide range of operating conditions. Technically, a general nonlinear dynamic model is firstly developed based on fundamental principles of diesel generators. Then, the system parameters of this model can be identified experimentally or partially retrieved from......The development of an intelligent control solution for a wide range of diesel generators is discussed. Compared with most existing solutions, the advantages of the proposed solution lie in two folds: (i) The proposed control has the plug-and-play capability which is reflected by an automatic...

  3. Augmenting Clozapine With Sertindole

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Emborg, Charlotte; Gydesen, Susanne

    2012-01-01

    . The study design was a 12-week, double-blind, randomized, placebo-controlled study including patients with International Statistical Classification of Diseases, 10th Revision schizophrenia (F20.0-F20.3) and treated with clozapine for at least 6 months who had not achieved sufficient response. Patients were...... Inventory, fasting glucose, lipids, and electrocardiogram. Clozapine augmentation with sertindole was not superior to placebo regarding total score or subscale score of the Positive and Negative Syndrome Scale, Clinical Global Impression, World Health Organization Quality of Life Brief, or Drug Attitude...... Inventory. No increased adverse effects compared with placebo were found. Four patients randomized to sertindole experienced a significant worsening of psychosis, and 2 of them required psychiatric admission. Metabolic parameters were unchanged during the study, but augmentation of clozapine with sertindole...

  4. Comparison between amniotomy, oxytocin or both for augmentation of labor in prolonged latent phase: a randomized controlled trial

    OpenAIRE

    Shalev Eliezer; Zafran Noah; Kadan Yfat; Garmi Gali; Nachum Zohar; Salim Raed

    2010-01-01

    Abstract Background A prolonged latent phase is independently associated with an increased incidence of subsequent labor abnormalities. We aimed to compare between oxytocin augmentation, amniotomy and a combination of both on the duration of labor among women with a prolonged latent phase. Methods Women with a singleton fetus in cephalic presentation who have a prolonged latent phase, were randomly allocated to amniotomy (group 1), oxytocin (group 2) or both (group 3). A group of women who pr...

  5. Electrowetting --A versatile tool for controlling microdrop generation

    Science.gov (United States)

    Malloggi, F.; Gu, H.; Banpurkar, A. G.; Vanapalli, S. A.; Mugele, F.

    2008-05-01

    Integrating insulator-covered electrodes into a microfluidic flow focusing device (FFD) we demonstrate enhanced flexibility and control of the flow of two non-miscible liquids based on electrowetting (EW). In the parameters space, determined by liquid inlet pressures, we identify a specific region where drops can only be generated and addressed via EW. In this regime we show that the size distribution and the frequency of drop generation can be controlled by the applied voltage and the width of voltage pulses. Moreover it turns out that with EW the drop size and the frequency can be tuned independently. Finally we show that the same drop generation phenomena can also be observed in the presence of surfactants.

  6. Admission control for differentiated services in future generation CDMA networks

    NARCIS (Netherlands)

    Tan, H.-P.; Núñez-Queija, R.; Gabor, A.F.; Boxma, O.J.

    2009-01-01

    Future Generation CDMA wireless systems, e.g., 3G, can simultaneously accommodate flow transmissions of users with widely heterogeneous applications. As radio resources are limited, we propose an admission control rule that protects users with stringent transmission bit-rate requirements ("streaming

  7. DARC: Next generation decentralized control framework for robot applications

    DEFF Research Database (Denmark)

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

    2013-01-01

    This paper presents DARC, a next generation control framework for robot applications. It is designed to be equally powerful in prototyping research projects and for building serious commercial robots running on low powered embedded hardware, thus closing the gab between research and industry...

  8. Augmented effects of EMG biofeedback interfaced with virtual reality on neuromuscular control and movement coordination during reaching in children with cerebral palsy.

    Science.gov (United States)

    Yoo, Ji Won; Lee, Dong Ryul; Cha, Young Joo; You, Sung Hyun

    2017-01-01

    The purpose of the present study was to compare therapeutic effects of an electromyography (EMG) biofeedback augmented by virtual reality (VR) and EMG biofeedback alone on the triceps and biceps (T:B) muscle activity imbalance and elbow joint movement coordination during a reaching motor taskOBJECTIVE: To compare therapeutic effects of an electromyography (EMG) biofeedback augmented by virtual reality (VR) and EMG biofeedback alone on the triceps and biceps muscle activity imbalance and elbow joint movement coordination during a reaching motor task in normal children and children with spastic cerebral palsy (CP). 18 children with spastic CP (2 females; mean±standard deviation = 9.5 ± 1.96 years) and 8 normal children (3 females; mean ± standard deviation = 9.75 ± 2.55 years) were recruited from a local community center. All children with CP first underwent one intensive session of EMG feedback (30 minutes), followed by one session of the EMG-VR feedback (30 minutes) after a 1-week washout period. Clinical tests included elbow extension range of motion (ROM), biceps muscle strength, and box and block test. EMG triceps and biceps (T:B) muscle activity imbalance and reaching movement acceleration coordination were concurrently determined by EMG and 3-axis accelerometer measurements respectively. Independent t-test and one-way repeated analysis of variance (ANOVA) were performed at p EMG biofeedback when augmented by virtual reality exercise games in children with spastic CP. The augmented EMG and VR feedback produced better neuromuscular balance control in the elbow joint than the EMG biofeedback alone.

  9. Aspects of User Experience in Augmented Reality

    OpenAIRE

    Madsen, Jacob Boesen

    2016-01-01

    In Augmented Reality applications, the real environment is annotated or enhanced with computer-generated graphics.This is a topic that has been researched in the recent decades, but for many people this is a brand new and never heard of topic.The main focus of this thesis is investigations in human factors related to Augmented Reality. This is investigated partly as how Augmented Reality applications are used in unsupervised settings, and partly in specific evaluations related to user perform...

  10. Virtual reality to augment robot-assisted gait training in non-ambulatory patients with a subacute stroke: a pilot randomized controlled trial.

    Science.gov (United States)

    Bergmann, Jeannine; Krewer, Carmen; Bauer, Petra; Koenig, Alexander; Riener, Robert; Müller, Friedemann

    2017-12-21

    Active performance is crucial for motor learning, and, together with motivation, is believed to be associated with a better rehabilitation outcome. Virtual reality (VR) is an innovative approach to engage and motivate patients during training. There is promising evidence for its efficiency in retraining upper limb function. However, there is insufficient proof for its effectiveness in gait training. To evaluate the acceptability of robot-assisted gait training (RAGT) with and without VR and the feasibility of potential outcome measures to guide the planning of a larger randomized controlled trial (RCT). Single-blind randomized controlled pilot trial with two parallel arms. Rehabilitation hospital. Twenty subacute stroke patients (64 ± 9 years) with a Functional Ambulation Classification (FAC) ≤2. 12 sessions (over 4 weeks) of either VR-augmented RAGT (intervention group) or standard RAGT (control group). Acceptability of the interventions (drop-out rate, questionnaire), patients' motivation (Intrinsic Motivation Inventory (IMI), individual mean walking time), and feasibility of potential outcome measures (completion rate and response to interventions) were determined. We found high acceptability of repetitive VR-augmented RAGT. The drop-out rate was 1/11 in the intervention and 4/14 in the control group. Patients of the intervention group spent significantly more time walking in the robot than the control group (per session and total walking time; p<0.03). In both groups, motivation measured with the IMI was high over the entire intervention period. The felt pressure and tension significantly decreased in the intervention group (p<0.01) and was significantly lower than in the control group at the last therapy session (r=-0.66, p=0.005). The FAC is suggested as a potential primary outcome measure for a definitive RCT, as it could be assessed in all patients and showed significant response to interventions (p<0.01). We estimated a sample size of 44 for a future

  11. Effects of mobile augmented reality learning compared to textbook learning on medical students: randomized controlled pilot study.

    Science.gov (United States)

    Albrecht, Urs-Vito; Folta-Schoofs, Kristian; Behrends, Marianne; von Jan, Ute

    2013-08-20

    By adding new levels of experience, mobile Augmented Reality (mAR) can significantly increase the attractiveness of mobile learning applications in medical education. To compare the impact of the heightened realism of a self-developed mAR blended learning environment (mARble) on learners to textbook material, especially for ethically sensitive subjects such as forensic medicine, while taking into account basic psychological aspects (usability and higher level of emotional involvement) as well as learning outcomes (increased learning efficiency). A prestudy was conducted based on a convenience sample of 10 third-year medical students. The initial emotional status was captured using the "Profile of Mood States" questionnaire (POMS, German variation); previous knowledge about forensic medicine was determined using a 10-item single-choice (SC) test. During the 30-minute learning period, the students were randomized into two groups: the first group consisted of pairs of students, each equipped with one iPhone with a preinstalled copy of mARble, while the second group was provided with textbook material. Subsequently, both groups were asked to once again complete the POMS questionnaire and SC test to measure changes in emotional state and knowledge gain. Usability as well as pragmatic and hedonic qualities of the learning material was captured using AttrakDiff2 questionnaires. Data evaluation was conducted anonymously. Descriptive statistics for the score in total and the subgroups were calculated before and after the intervention. The scores of both groups were tested against each other using paired and unpaired signed-rank tests. An item analysis was performed for the SC test to objectify difficulty and selectivity. Statistically significant, the mARble group (6/10) showed greater knowledge gain than the control group (4/10) (Wilcoxon z=2.232, P=.03). The item analysis of the SC test showed a difficulty of P=0.768 (s=0.09) and a selectivity of RPB=0.2. For m

  12. Effects of Mobile Augmented Reality Learning Compared to Textbook Learning on Medical Students: Randomized Controlled Pilot Study

    Science.gov (United States)

    2013-01-01

    Background By adding new levels of experience, mobile Augmented Reality (mAR) can significantly increase the attractiveness of mobile learning applications in medical education. Objective To compare the impact of the heightened realism of a self-developed mAR blended learning environment (mARble) on learners to textbook material, especially for ethically sensitive subjects such as forensic medicine, while taking into account basic psychological aspects (usability and higher level of emotional involvement) as well as learning outcomes (increased learning efficiency). Methods A prestudy was conducted based on a convenience sample of 10 third-year medical students. The initial emotional status was captured using the “Profile of Mood States” questionnaire (POMS, German variation); previous knowledge about forensic medicine was determined using a 10-item single-choice (SC) test. During the 30-minute learning period, the students were randomized into two groups: the first group consisted of pairs of students, each equipped with one iPhone with a preinstalled copy of mARble, while the second group was provided with textbook material. Subsequently, both groups were asked to once again complete the POMS questionnaire and SC test to measure changes in emotional state and knowledge gain. Usability as well as pragmatic and hedonic qualities of the learning material was captured using AttrakDiff2 questionnaires. Data evaluation was conducted anonymously. Descriptive statistics for the score in total and the subgroups were calculated before and after the intervention. The scores of both groups were tested against each other using paired and unpaired signed-rank tests. An item analysis was performed for the SC test to objectify difficulty and selectivity. Results Statistically significant, the mARble group (6/10) showed greater knowledge gain than the control group (4/10) (Wilcoxon z=2.232, P=.03). The item analysis of the SC test showed a difficulty of P=0.768 (s=0.09) and a

  13. Augmented Reality Tower Technology Assessment

    Science.gov (United States)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  14. Resonance analysis in parallel voltage-controlled Distributed Generation inverters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Chen, Zhe

    2013-01-01

    of the inverters and the remaining system dynamics. This paper addresses the later interactions and the consequent resonances through the frequency-domain analysis of the inverters output impedances and the remaining equivalent network impedance. Furthermore, impacts of the virtual output impedance loop......Thanks to the fast responses of the inner voltage and current control loops, the dynamic behaviors of parallel voltage-controlled Distributed Generation (DG) inverters not only relies on the stability of load sharing among them, but subjects to the interactions between the voltage control loops...

  15. Next generation Zero-Code control system UI

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Developing ergonomic user interfaces for control systems is challenging, especially during machine upgrade and commissioning where several small changes may suddenly be required. Zero-code systems, such as *Inspector*, provide agile features for creating and maintaining control system interfaces. More so, these next generation Zero-code systems bring simplicity and uniformity and brake the boundaries between Users and Developers. In this talk we present *Inspector*, a CERN made Zero-code application development system, and we introduce the major differences and advantages of using Zero-code control systems to develop operational UI.

  16. Development of remote control software for multiformat test signal generator

    Directory of Open Access Journals (Sweden)

    Gao Yang

    2017-01-01

    Full Text Available The multi format test signal generator mentioned in this paper is the video signal generator named TG8000 produced by Tektronix Company. I will introduce the function about remote control for signal generator, how to connect the computer to the instrument, and how to remote control. My topic uses my computer to connect the instrument through the 10/100/1000 BASE-T port on the rear panel of TG8000. Then I write program to transmit SCPI (Standard Commands for Programmable Instruments to control TG8000. The application is running on the Windows operating system, the programming language is C#, development environment is Microsoft Visual Studio 2010, using the TCP/IP protocol based on Socket. And the method of remote control refers to the application called TGSetup which is developed by Tektronix Company. This paper includes a brief summary of the basic principle, and introduce for details about the process of remote control software development, and how to use my software. In the end, I will talk about the advantages of my software compared with another one.

  17. Using evolution to generate sustainable malaria control with spatial repellents.

    Science.gov (United States)

    Lynch, Penelope Anne; Boots, Mike

    2016-10-25

    Evolution persistently undermines vector control programs through insecticide resistance. Here we propose a novel strategy which instead exploits evolution to generate and sustain new control tools. Effective spatial repellents are needed to keep vectors out of houses. Our approach generates such new repellents by combining a high-toxicity insecticide with a candidate repellent initially effective against only part of the vector population. By killing mosquitoes that enter treated properties the insecticide selects for vector phenotypes deflected by the repellent, increasing efficacy of the repellent against the target vector population and in turn protecting the insecticide against the spread of insecticide resistance. Using such evolved spatial repellents offers an evolutionarily sustainable, 'double-dip' system of disease control combining mortality and repellence. We formalize this idea using models which explore vector population genetics and disease transmission probabilities and show that using evolved spatial repellents is theoretically achievable, effective and sustainable.

  18. Digital integrated control of a Mach 2.5 mixed-compression supersonic inlet and an augmented mixed-flow turbofan engine

    Science.gov (United States)

    Batterton, P. G.; Arpasi, D. J.; Baumbick, R. J.

    1974-01-01

    A digitally implemented integrated inlet-engine control system was designed and tested on a mixed-compression, axisymmetric, Mach 2.5, supersonic inlet with 45 percent internal supersonic area contraction and a TF30-P-3 augmented turbofan engine. The control matched engine airflow to available inlet airflow. By monitoring inlet terminal shock position and over-board bypass door command, the control adjusted engine speed so that in steady state, the shock would be at the desired location and the overboard bypass doors would be closed. During engine-induced transients, such as augmentor light-off and cutoff, the inlet operating point was momentarily changed to a more supercritical point to minimize unstarts. The digital control also provided automatic inlet restart. A variable inlet throat bleed control, based on throat Mach number, provided additional inlet stability margin.

  19. Robust Control of Aeronautical Electrical Generators for Energy Management Applications

    Directory of Open Access Journals (Sweden)

    Giacomo Canciello

    2017-01-01

    Full Text Available A new strategy for the control of aeronautical electrical generators via sliding manifold selection is proposed, with an associated innovative intelligent energy management strategy used for efficient power transfer between two sources providing energy to aeronautical loads, having different functionalities and priorities. Electric generators used for aeronautical application involve several machines, including a main generator and an exciter. Standard regulators (PI or PID-like are normally used for the rectification of the generator voltage to be used to supply a high-voltage DC bus. The regulation is obtained by acting on a DC/DC converter that imposes the field voltage of the exciter. In this paper, the field voltage is fed to the generator windings by using a second-order sliding mode controller, resulting into a stable, robust (against disturbances action and a fast convergence to the desired reference. By using this strategy, an energy management strategy is proposed that dynamically changes the voltage set point, in order to intelligently transfer power between two voltage busses. Detailed simulation results are provided in order to show the effectiveness of the proposed energy management strategy in different scenarios.

  20. Embedded model control GNC for the Next Generation Gravity Mission

    Science.gov (United States)

    Colangelo, Luigi; Massotti, Luca; Canuto, Enrico; Novara, Carlo

    2017-11-01

    A Next Generation Gravity Mission (NGGM) concept for measuring the Earth's variable gravity field has been recently proposed by ESA. The mission objective consists in measuring the temporal variations of the Earth gravity field over a long-time span, with very high spatial and temporal resolutions. This paper focuses on the guidance, navigation and control (GNC) design for the science phase of the NGGM mission. NGGM will consist of a two-satellite long-distance formation like GRACE, where each satellite will be controlled to be drag-free like GOCE. Satellite-to-satellite distance variations, encoding gravity anomalies, will be measured by laser interferometry. The formation satellites, distant up to 200 km, will fly in a quasi-polar orbit at an Earth altitude between 300 and 450 km. Orbit and formation control counteract bias and drift of the residual drag-free accelerations, in order to reach orbit/formation long-term stability. Drag-free control allows the formation to fly counteracting the atmospheric drag, ideally subject only to gravity. Orbit and formation control, designed through the innovative Integrated Formation Control (IFC), have been integrated into a unique control system, aiming at stabilizing the formation triangle consisting of satellites and Earth Center of Masses. In addition, both spacecraft must align their control axis to the satellite-to-satellite line (SSL) with micro-radian accuracy. This is made possible by specific optical sensors and the inter-satellite laser interferometer, capable of materializing the SSL. Such sensors allow each satellite to pursue an autonomous alignment after a suitable acquisition procedure. Pointing control is severely constrained by the angular drag-free control, which must ideally zero the angular acceleration vector, in the science frequency band. The control unit has been designed according to the Embedded Model Control methodology and is organized in a hierarchical way, where the drag-free control plays the

  1. UNICOS CPC6: Automated Code Generation for Process Control Applications

    CERN Document Server

    Fernandez Adiego, B; Prieto Barreiro, I

    2011-01-01

    The Continuous Process Control package (CPC) is one of the components of the CERN Unified Industrial Control System framework (UNICOS) [1]. As a part of this framework, UNICOS-CPC provides a well defined library of device types, amethodology and a set of tools to design and implement industrial control applications. The new CPC version uses the software factory UNICOS Application Builder (UAB) [2] to develop CPC applications. The CPC component is composed of several platform oriented plugins PLCs and SCADA) describing the structure and the format of the generated code. It uses a resource package where both, the library of device types and the generated file syntax, are defined. The UAB core is the generic part of this software, it discovers and calls dynamically the different plug-ins and provides the required common services. In this paper the UNICOS CPC6 package is introduced. It is composed of several plug-ins: the Instance generator and the Logic generator for both, Siemens and Schneider PLCs, the SCADA g...

  2. Robust Adaptive Reactive Power Control for Doubly Fed Induction Generator

    Directory of Open Access Journals (Sweden)

    Huabin Wen

    2014-01-01

    Full Text Available The problem of reactive power control for mains-side inverter (MSI in doubly fed induction generator (DFIG is studied in this paper. To accommodate the modelling nonlinearities and inherent uncertainties, a novel robust adaptive control algorithm for MSI is proposed by utilizing Lyapunov theory that ensures asymptotic stability of the system under unpredictable external disturbances and significant parametric uncertainties. The distinguishing benefit of the aforementioned scheme consists in its capabilities to maintain satisfactory performance under varying operation conditions without the need for manually redesigning or reprogramming the control gains in contrast to the commonly used PI/PID control. Simulations are also built to confirm the correctness and benefits of the control scheme.

  3. A Density Control Based Adaptive Hexahedral Mesh Generation Algorithm

    Directory of Open Access Journals (Sweden)

    Xiangwei Zhang

    2016-12-01

    Full Text Available A density control based adaptive hexahedral mesh generation algorithm for three dimensional models is presented in this paper. The first step of this algorithm is to identify the characteristic boundary of the solid model which needs to be meshed. Secondly, the refinement fields are constructed and modified according to the conformal refinement templates, and used as a metric to generate an initial grid structure. Thirdly, a jagged core mesh is generated by removing all the elements in the exterior of the solid model. Fourthly, all of the surface nodes of the jagged core mesh are matching to the surfaces of the model through a node projection process. Finally, the mesh quality such as topology and shape is improved by using corresponding optimization techniques.

  4. Voltage Control in Wind Power Plants with Doubly Fed Generators

    DEFF Research Database (Denmark)

    Garcia, Jorge Martinez

    the reactive power operation of the converters, in steadystate, within a maximum band of 10 %. It is clear that an on-load tap changer system will help to keep the stator voltage close to its nominal value, but the action of the mechanically switched capacitors is badly influencing the on-load tap changer line......In this work, the process of designing a wind power plant composed of; doubly fed induction generators, a static compensator unit, mechanically switched capacitors and on-load tap changer, for voltage control is shown. The selected control structure is based on a decentralized system, since...... measured current at medium voltage, thus reducing the tap moving operations. Finally, due to the wind power plant reactive power is sized for maximum active power level, it is expected that a big amount of reactive power remains unused most of the time due to the wind power generation characteristics...

  5. Generation companies decision-making modeling by linear control theory

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Alcaraz, G. [Programa de Graduados e Investigacion en Ingenieria Electrica. Departamento de Ingenieria Electrica y Electronica, Instituto Tecnologico de Morelia. Av. Tecnologico 1500, Col. Lomas de Santiaguito 58120. Morelia, Mich. (Mexico); Sheble, Gerald B. [INESC Porto, Faculdade de Engenharia, Universidade do Porto, Campus da FEUP, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)

    2010-07-15

    This paper proposes four decision-making procedures to be employed by electric generating companies as part of their bidding strategies when competing in an oligopolistic market: naive, forward, adaptive, and moving average expectations. Decision-making is formulated in a dynamic framework by using linear control theory. The results reveal that interactions among all GENCOs affect market dynamics. Several numerical examples are reported, and conclusions are presented. (author)

  6. Reduction of Adipose Tissue Formation by the Controlled Release of BMP-2 Using a Hydroxyapatite-Coated Collagen Carrier System for Sinus-Augmentation/Extraction-Socket Grafting

    Directory of Open Access Journals (Sweden)

    Jung-Seok Lee

    2015-11-01

    Full Text Available The effects of hydroxyapatite (HA-coating onto collagen carriers for application of recombinant human bone morphogenetic protein 2 (rhBMP-2 on cell differentiation in vitro, and on in vivo healing patterns after sinus-augmentation and alveolar socket-grafting were evaluated. In vitro induction of osteogenic/adipogenic differentiation was compared between the culture media with rhBMP-2 solution and with the released rhBMP-2 from the control collagen and from the HA-coated collagen. Demineralized bovine bone and collagen/HA-coated collagen were grafted with/without rhBMP-2 in sinus-augmentation and tooth-extraction-socket models. Adipogenic induction by rhBMP-2 released from HA-coated collagen was significantly reduced compared to collagen. In the sinus-augmentation model, sites that received rhBMP-2 exhibited large amounts of vascular tissue formation at two weeks and increased adipose tissue formation at eight weeks; this could be significantly reduced by using HA-coated collagen as a carrier for rhBMP-2. In extraction-socket grafting, dimensional reduction of alveolar ridge was significantly decreased at sites received rhBMP-2 compared to control sites, but adipose tissue was increased within the regenerated socket area. In conclusion, HA-coated collagen carrier for Escherichia coli-derived rhBMP-2 (ErhBMP-2 may reduce in vitro induction of adipogenic differentiation and in vivo adipose bone marrow tissue formation in bone tissue engineering by ErhBMP-2.

  7. Randomized Controlled Trial Comparing Orthosis Augmented by Either Stretching or Stretching and Strengthening for Stage II Tibialis Posterior Tendon Dysfunction.

    Science.gov (United States)

    Houck, Jeff; Neville, Christopher; Tome, Josh; Flemister, Adolph

    2015-09-01

    The value of strengthening and stretching exercises combined with orthosis treatment in a home-based program has not been evaluated. The purpose of this study was to compare the effects of augmenting orthosis treatment with either stretching or a combination of stretching and strengthening in participants with stage II tibialis posterior tendon dysfunction (TPTD). Participants included 39 patients with stage II TPTD who were recruited from a medical center and then randomly assigned to a strengthening or stretching treatment group. Excluding 3 dropouts, there were 19 participants in the strengthening group and 17 in the stretching group. The stretching treatment consisted of a prefabricated orthosis used in conjunction with stretching exercises. The strengthening treatment consisted of a prefabricated orthosis used in conjunction with the stretching and strengthening exercises. The main outcome measures were self-report (ie, Foot Function Index and Short Musculoskeletal Function Assessment) and isometric deep posterior compartment strength. Two-way analysis of variance was used to test for differences between groups at 6 and 12 weeks after starting the exercise programs. Both groups significantly improved in pain and function over the 12-week trial period. The self-report measures showed minimal differences between the treatment groups. There were no differences in isometric deep posterior compartment strength. A moderate-intensity, home-based exercise program was minimally effective in augmenting orthosis wear alone in participants with stage II TPTD. Level I, prospective randomized study. © The Author(s) 2015.

  8. Stator Current Harmonic Control with Resonant Controller for Doubly Fed Induction Generator

    DEFF Research Database (Denmark)

    Liu, Changjin; Blaabjerg, Frede; Chen, Wenjie

    2012-01-01

    rotor current control loop for harmonic suppression. The overall control scheme is implemented in dq frame. Based on a mathematical model of the DFIG control system, the effects on system stability using the resonant controller, an analysis of the steady-state error, and the dynamic performance......Voltage harmonics in the grid can introduce stator current harmonics in a doubly fed induction generator (DFIG) wind turbine system, which may potentially impact the generated power quality. Therefore, wind turbine current controllers need to be designed to eliminate the impact of grid voltage...

  9. Control of the droplet generation by an infrared laser

    Directory of Open Access Journals (Sweden)

    Zhibin Wang

    2018-01-01

    Full Text Available In this work, the control of the droplet generation by a focused infrared (IR laser with a wavelength of 1550 nm was studied, in which the liquid water and the oil with the surfactant of Span 80 were employed as the disperse and continuous phases, respectively. The characteristics of the droplet generation controlled by the laser was explored under various flow rates, laser powers and spot positions and the comparison between the cases with/without the laser was also performed. The results showed that when the laser was focused on the region away from the outlet of the liquid water inflow channel, the droplet shedding was blocked due to the IR laser heating induced thermocapillary flow, leading to the increase of the droplet volume and the cycle time of the droplet generation as compared to the case without the laser. Decreasing the continuous phase flow rate led to the increase of the droplet volume, cycle time of the droplet generation and the volume increase ratio, while increasing the disperse phase flow rate led to the increase of the droplet volume and the decrease of the cycle time and volume increase ratio. For a given flow rate ratio between the continuous and disperse phases, the increase of the flow rates decreased the volume increase ratio. In addition, it is also found that the droplet volume, the cycle time and the volume increase ratio all increased with the laser power. When the laser was focused at the inlet of the downstream channel, the droplet volume, the cycle time and the volume increase ratio were the largest. Moving the laser spot to the downstream or upstream led to the decrease of them. When the laser was focused on the outlet of the liquid water inflow channel, the generated droplet volume and cycle time of the droplet generation were even lower than the case without the laser because of the lowered viscosity. This works provides a comprehensive understanding of the characteristics of the droplet generation controlled

  10. Characterization of the metabolic phenotype of rapamycin-treated CD8+ T cells with augmented ability to generate long-lasting memory cells.

    Directory of Open Access Journals (Sweden)

    Shan He

    Full Text Available BACKGROUND: Cellular metabolism plays a critical role in regulating T cell responses and the development of memory T cells with long-term protections. However, the metabolic phenotype of antigen-activated T cells that are responsible for the generation of long-lived memory cells has not been characterized. DESIGN AND METHODS: Using lymphocytic choriomeningitis virus (LCMV peptide gp33-specific CD8(+ T cells derived from T cell receptor transgenic mice, we characterized the metabolic phenotype of proliferating T cells that were activated and expanded in vitro in the presence or absence of rapamycin, and determined the capability of these rapamycin-treated T cells to generate long-lived memory cells in vivo. RESULTS: Antigen-activated CD8(+ T cells treated with rapamycin gave rise to 5-fold more long-lived memory T cells in vivo than untreated control T cells. In contrast to that control T cells only increased glycolysis, rapamycin-treated T cells upregulated both glycolysis and oxidative phosphorylation (OXPHOS. These rapamycin-treated T cells had greater ability than control T cells to survive withdrawal of either glucose or growth factors. Inhibition of OXPHOS by oligomycin significantly reduced the ability of rapamycin-treated T cells to survive growth factor withdrawal. This effect of OXPHOS inhibition was accompanied with mitochondrial hyperpolarization and elevation of reactive oxygen species that are known to be toxic to cells. CONCLUSIONS: Our findings indicate that these rapamycin-treated T cells may represent a unique cell model for identifying nutrients and signals critical to regulating metabolism in both effector and memory T cells, and for the development of new methods to improve the efficacy of adoptive T cell cancer therapy.

  11. Complementary Power Control for Doubly Fed Induction Generator-Based Tidal Stream Turbine Generation Plants

    Directory of Open Access Journals (Sweden)

    Khaoula Ghefiri

    2017-06-01

    Full Text Available The latest forecasts on the upcoming effects of climate change are leading to a change in the worldwide power production model, with governments promoting clean and renewable energies, as is the case of tidal energy. Nevertheless, it is still necessary to improve the efficiency and lower the costs of the involved processes in order to achieve a Levelized Cost of Energy (LCoE that allows these devices to be commercially competitive. In this context, this paper presents a novel complementary control strategy aimed to maximize the output power of a Tidal Stream Turbine (TST composed of a hydrodynamic turbine, a Doubly-Fed Induction Generator (DFIG and a back-to-back power converter. In particular, a global control scheme that supervises the switching between the two operation modes is developed and implemented. When the tidal speed is low enough, the plant operates in variable speed mode, where the system is regulated so that the turbo-generator module works in maximum power extraction mode for each given tidal velocity. For this purpose, the proposed back-to-back converter makes use of the field-oriented control in both the rotor side and grid side converters, so that a maximum power point tracking-based rotational speed control is applied in the Rotor Side Converter (RSC to obtain the maximum power output. Analogously, when the system operates in power limitation mode, a pitch angle control is used to limit the power captured in the case of high tidal speeds. Both control schemes are then coordinated within a novel complementary control strategy. The results show an excellent performance of the system, affording maximum power extraction regardless of the tidal stream input.

  12. Improved inertial control for permanent magnet synchronous generator wind turbine generators

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ziping; Gao, Wenzhong; Wang, Xiao; Kang, Moses; Hwang, Min; Kang, Yong Cheol; Gevogian, Vahan; Muljadi, Eduard

    2016-05-31

    With increasing integrations of large-scale systems based on permanent magnet synchronous generator wind turbine generators (PMSG-WTGs), the overall inertial response of a power system will tend to deteriorate as a result of the decoupling of rotor speed and grid frequency through the power converter as well as the scheduled retirement of conventional synchronous generators. Thus, PMSG-WTGs can provide value to an electric grid by contributing to the system's inertial response through the inherent kinetic energy stored in their rotating masses and fast power converter control. In this study, an improved inertial control method based on the maximum power point tracking operation curve is introduced to enhance the overall frequency support capability of PMSG-WTGs in the case of large supply-demand imbalances. Moreover, this method is implemented in the CART2-PMSG integrated model in MATLAB/Simulink to investigate its impact on the wind turbine's structural loads during the inertial response process. Simulation results indicate that the proposed method can effectively reduce the frequency nadir, arrest the rate of change of frequency, and alleviate the secondary frequency dip while imposing no negative impact on the major mechanical components of the wind turbine.

  13. Intelligent system for controlling of generator groups; Sistema inteligente para controle de grupos geradores

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Ricardo [RF Eletro-Eletronica (Brazil); Suppa, Mauricio R. [GESTAL - Gestao de Energia e Utilidades Ltda, SP (Brazil)

    1998-10-01

    The use of generation-motor groups as an alternative to the supplying the concessionaires is presented, aiming the cost reduction and electric power energy conservation. The technical and economical advantages of an intelligent system implantation for generators control and supervision are highlighted, such as open and flexible architecture, maintenance easiness and long distance management.

  14. The clinical value of membranes in bone augmentation procedures in oral implantology: 
A systematic review of randomised controlled trials

    NARCIS (Netherlands)

    Jonker, Brend P.; Roeloffs, Maarten W. K.; Wolvius, Eppo B.; Pijpe, Justin

    2016-01-01

    To determine the clinical value of membranes in bone augmentation procedures such as ridge augmentation with simultaneous (one-stage) and delayed (two-stage) implant placement, sinus augmentation surgery, ridge preservation and immediate implant placement. In April 2016, Embase, Medline (Ovid-SP),

  15. Control of Next Generation Aircraft and Wind Turbines

    Science.gov (United States)

    Frost, Susan

    2010-01-01

    The first part of this talk will describe some of the exciting new next generation aircraft that NASA is proposing for the future. These aircraft are being designed to reduce aircraft fuel consumption and environmental impact. Reducing the aircraft weight is one approach that will be used to achieve these goals. A new control framework will be presented that enables lighter, more flexible aircraft to maintain aircraft handling qualities, while preventing the aircraft from exceeding structural load limits. The second part of the talk will give an overview of utility-scale wind turbines and their control. Results of collaboration with Dr. Balas will be presented, including new theory to adaptively control the turbine in the presence of structural modes, with the focus on the application of this theory to a high-fidelity simulation of a wind turbine.

  16. Wind Turbine Contingency Control Through Generator De-Rating

    Science.gov (United States)

    Frost, Susan; Goebel, Kai; Balas, Mark

    2013-01-01

    Maximizing turbine up-time and reducing maintenance costs are key technology drivers for wind turbine operators. Components within wind turbines are subject to considerable stresses due to unpredictable environmental conditions resulting from rapidly changing local dynamics. In that context, systems health management has the aim to assess the state-of-health of components within a wind turbine, to estimate remaining life, and to aid in autonomous decision-making to minimize damage to the turbine. Advanced contingency control is one way to enable autonomous decision-making by providing the mechanism to enable safe and efficient turbine operation. The work reported herein explores the integration of condition monitoring of wind turbines with contingency control to balance the trade-offs between maintaining system health and energy capture. The contingency control involves de-rating the generator operating point to achieve reduced loads on the wind turbine. Results are demonstrated using a high fidelity simulator of a utility-scale wind turbine.

  17. Augmented feedback supports skill transfer and reduces high-risk injury landing mechanics: a double-blind, randomized controlled laboratory study.

    Science.gov (United States)

    Myer, Gregory D; Stroube, Benjamin W; DiCesare, Christopher A; Brent, Jensen L; Ford, Kevin R; Heidt, Robert S; Hewett, Timothy E

    2013-03-01

    There is a current need to produce a simple, yet effective method for screening and targeting possible deficiencies related to increased anterior cruciate ligament (ACL) injury risk. Frontal plane knee angle (FPKA) during a drop vertical jump will decrease upon implementing augmented feedback into a standardized sport training program. Controlled laboratory study. Thirty-seven female participants (mean ± SD: age, 14.7 ± 1.5 years; height, 160.9 ± 6.8 cm; weight, 54.5 ± 7.2 kg) were trained over 8 weeks. During each session, each participant received standardized training consisting of strength training, plyometrics, and conditioning. They were also videotaped running on a treadmill at a standardized speed and performing a repeated tuck jump for 10 seconds. Study participants were randomized into 2 groups and received augmented feedback on either their jumping (AF) or sprinting (CTRL) form. Average (mean of 3 trials) and most extreme (trial with greatest knee abduction) FPKA were calculated from 2-dimensional video captured during performance of the drop vertical jump. After testing, a main effect of time was noted, with the AF group reducing their FPKA average by 37.9% over the 3 trials while the CTRL group demonstrated a 26.7% reduction average across the 3 trials (P risk. The ability of the augmented feedback to support the transfer of skills and injury risk factor reductions across different tasks provides exciting new evidence related to how neuromuscular training may ultimately cross over into retained biomechanics that reduce ACL injuries during sport. The tuck jump assessment's ease of use makes it a timely and economically favorable method to support ACL prevention strategies in young girls.

  18. Introduction of respiratory pattern generators into models of respiratory control.

    Science.gov (United States)

    Longobardo, Guy; Evangelisti, Carlo J; Cherniack, Neil S

    2005-10-12

    We have adapted two models previously proposed as respiratory pattern generators (RPGs) into a neurochemical feed back control model of ventilation. The RPG models, non-dimensional as originally presented, consisted of oscillating circuits of either two or five interconnected neurons [Matsugu, M., Duffin, J., Poon, C.-S., 1998. Entrainment, instability, quasi-periodicity, and chaos in a compound neural oscillator. J. Comput. Neurosci. 5, 35-51; Botros, S.M., Bruce, E.N., 1990. Neural network implementation of a three-phase model of respiratory rhythm generation. Biol. Cybern. 63, 143-153]. The neurochemical model into which they were integrated [Longobardo, G., Evangelisti, C.J., Cherniack, N.S., 2002. Effects of neural drives on breathing in the awake state in humans. Respir. Physiol. 129, 317-333] included the effects of cerebral blood flow variation with CO2, vagal stretch receptors input and a multicompartment model of carbon dioxide stores. The methodology is described whereby these neuronal oscillator networks were quantified, a necessary step for their inclusion as RPGs in broader models of the overall control of respiration. Subsequent simulations of the ventilation response to carbon dioxide with either respiratory pattern generator model exhibited only a limited range in which tidal volume and frequency increased with increasing respiratory drive. With both models, frequency peaked and then declined, as did ventilation when P CO2 was greater than normal. The range of the models was extended if the respiratory pattern generators were considered to be composed of multiple neuronal oscillators or a single oscillator in which there was increasing phasic input that was gated or pacemaker driven.

  19. The Switching Generator: New Clock-Controlled Generator with Resistance against the Algebraic and Side Channel Attacks

    Directory of Open Access Journals (Sweden)

    Jun Choi

    2015-06-01

    Full Text Available Since Advanced Encryption Standard (AES in stream modes, such as counter (CTR, output feedback (OFB and cipher feedback (CFB, can meet most industrial requirements, the range of applications for dedicated stream ciphers is decreasing. There are many attack results using algebraic properties and side channel information against stream ciphers for hardware applications. Al-Hinai et al. presented an algebraic attack approach to a family of irregularly clock-controlled linear feedback shift register systems: the stop and go generator, self-decimated generator and alternating step generator. Other clock-controlled systems, such as shrinking and cascade generators, are indeed vulnerable against side channel attacks. To overcome these threats, new clock-controlled systems were presented, e.g., the generalized alternating step generator, cascade jump-controlled generator and mutual clock-controlled generator. However, the algebraic attack could be applied directly on these new systems. In this paper, we propose a new clock-controlled generator: the switching generator, which has resistance to algebraic and side channel attacks. This generator also preserves both security properties and the efficiency of existing clock-controlled generators.

  20. Creatine fails to augment the benefits from resistance training in patients with HIV infection: a randomized, double-blind, placebo-controlled study.

    Directory of Open Access Journals (Sweden)

    Giorgos K Sakkas

    Full Text Available Progressive resistance exercise training (PRT improves physical functioning in patients with HIV infection. Creatine supplementation can augment the benefits derived from training in athletes and improve muscle function in patients with muscle wasting. The objective of this study was to determine whether creatine supplementation augments the effects of PRT on muscle strength, energetics, and body composition in HIV-infected patients.This is a randomized, double blind, placebo-controlled, clinical research center-based, outpatient study in San Francisco. 40 HIV-positive men (20 creatine, 20 placebo enrolled in a 14-week study. Subjects were randomly assigned to receive creatine monohydrate or placebo for 14 weeks. Treatment began with a loading dose of 20 g/day or an equivalent number of placebo capsules for 5 days, followed by maintenance dosing of 4.8 g/day or placebo. Beginning at week 2 and continuing to week 14, all subjects underwent thrice-weekly supervised resistance exercise while continuing on the assigned study medication (with repeated 6-week cycles of loading and maintenance. The main outcome measurements included muscle strength (one repetition maximum, energetics ((31P magnetic resonance spectroscopy, composition and size (magnetic resonance imaging, as well as total body composition (dual-energy X-ray absorptiometry. Thirty-three subjects completed the study (17 creatine, 16 placebo. Strength increased in all 8 muscle groups studied following PRT, but this increase was not augmented by creatine supplementation (average increase 44 vs. 42%, difference 2%, 95% CI -9.5% to 13.9% in creatine and placebo, respectively. There were no differences between groups in changes in muscle energetics. Thigh muscle cross-sectional area increased following resistance exercise, with no additive effect of creatine. Lean body mass (LBM increased to a significantly greater extent with creatine. CONCLUSIONS / SIGNIFICANCE: Resistance exercise improved

  1. A Family of Controllable Cellular Automata for Pseudorandom Number Generation

    OpenAIRE

    Guan, SU; Zhang, S.

    2002-01-01

    In this paper, we present a family of novel Pseudorandom Number Generators (PRNGs) based on Controllable Cellular Automata (CCA) ─ CCA0, CCA1, CCA2 (NCA), CCA3 (BCA), CCA4 (asymmetric NCA), CCA5, CCA6 and CCA7 PRNGs. The ENT and DIEHARD test suites are used to evaluate the randomness of these CCA PRNGs. The results show that their randomness is better than that of conventional CA and PCA PRNGs while they do not lose the structure simplicity of 1-d CA. Moreover, their randomness can be compara...

  2. Control and Analysis of Droop and Reverse Droop Controllers for Distributed Generations

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Vasquez, Juan Carlos

    2014-01-01

    a more complete primary control for DG systems that integrates with both VCM and CCM units. The power management can be uniformly achieved by designing proportional droop and reverse droop parameters. And the power sharing effect among CCM and VCM DG units is discussed. Finally, hardware......This paper addresses control and analysis of droop and reverse droop control for distributed generations (DG). The droop control is well known applied to the voltage control mode (VCM) DG units, but has limitation when implemented on the current control mode (CCM) units. Therefore, this paper gives...

  3. "Bubble-on-demand" generator with precise adsorption time control.

    Science.gov (United States)

    Zawala, J; Niecikowska, A

    2017-09-01

    The paper presents the principles of our new single bubble generator, which allows a precise control of bubble formation in pure liquids and surfactant solutions, i.e., their detachment frequency and the adsorption time at their motionless surface. We show that the bubbles with equilibrium size can be produced at the capillaries of various orifice diameters (0.022-0.128 mm) on demand and with outstanding reproducibility. Moreover, it is shown that a fully automatized and programmable bubble trap, synchronized with bubble detachment frequency, can be used to (i) control the radius of the released bubble and (ii) precisely adjust the initial adsorption coverage over the surface of detaching bubble, and hence to study the influence of adsorption coverage degree on kinetics of dynamic adsorption layer formation at the rising bubble surface.

  4. "Bubble-on-demand" generator with precise adsorption time control

    Science.gov (United States)

    Zawala, J.; Niecikowska, A.

    2017-09-01

    The paper presents the principles of our new single bubble generator, which allows a precise control of bubble formation in pure liquids and surfactant solutions, i.e., their detachment frequency and the adsorption time at their motionless surface. We show that the bubbles with equilibrium size can be produced at the capillaries of various orifice diameters (0.022-0.128 mm) on demand and with outstanding reproducibility. Moreover, it is shown that a fully automatized and programmable bubble trap, synchronized with bubble detachment frequency, can be used to (i) control the radius of the released bubble and (ii) precisely adjust the initial adsorption coverage over the surface of detaching bubble, and hence to study the influence of adsorption coverage degree on kinetics of dynamic adsorption layer formation at the rising bubble surface.

  5. Beamlet pulse-generation and wavefront-control system

    Energy Technology Data Exchange (ETDEWEB)

    Van Wonterghem, B.M.; Salmon, J.T.; Wilcox, R.W.

    1996-06-01

    The Beamlet pulse-generation system (or {open_quotes}front end{close_quotes}) refers to the laser hardware that generates the spatially and temporally shaped pulse that is injected into the main laser cavity. All large ICF lasers have pulse-generation systems that typically consist of a narrow-band oscillator, elector-optic modulators for temporal and bandwidth shaping, and one or more preamplifiers. Temporal shaping is used to provide the desired laser output pulse shape and also to compensate for gain saturation effects in the large-aperture amplifiers. Bandwidth is applied to fulfill specific target irradiation requirements and to avoid stimulated Brillouin scattering (SBS) in large-aperture laser components. Usually the sharp edge of the beam`s spatial intensity profile is apodized before injection in the main amplifier beam line. This prevents large-amplitude ripples on the intensity profile. Here the authors briefly review the front-end design and discuss improvements to the oscillator and modulator systems. Their main focus, however, is to describe Beamlet`s novel beam-shaping and wavefront-control systems that have recently been fully activated and tested.

  6. Microrelief-Controlled Overland Flow Generation: Laboratory and Field Experiments

    Directory of Open Access Journals (Sweden)

    Xuefeng Chu

    2015-01-01

    Full Text Available Surface microrelief affects overland flow generation and the related hydrologic processes. However, such influences vary depending on other factors such as rainfall characteristics, soil properties, and initial soil moisture conditions. Thus, in-depth research is needed to better understand and evaluate the combined effects of these factors on overland flow dynamics. The objective of this experimental study was to examine how surface microrelief, in conjunction with the factors of rainfall, soil, and initial moisture conditions, impacts overland flow generation and runoff processes in both laboratory and field settings. A series of overland flow experiments were conducted for rough and smooth surfaces that represented distinct microtopographic characteristics and the experimental data were analyzed and compared. Across different soil types and initial moisture conditions, both laboratory and field experiments demonstrated that a rough soil surface experienced a delayed initiation of runoff and featured a stepwise threshold flow pattern due to the microrelief-controlled puddle filling-spilling-merging dynamics. It was found from the field experiments that a smooth plot surface was more responsive to rainfall variations especially during an initial rainfall event. However, enhanced capability of overland flow generation and faster puddle connectivity of a rough field plot occurred during the subsequent rain events.

  7. Extreme Precision Environmental Control for Next Generation Radial Velocity Spectrographs

    Science.gov (United States)

    Stefansson, Gudmundur K.; Hearty, Fred; Levi, Eric; Robertson, Paul; Mahadevan, Suvrath; Bender, Chad; Nelson, Matt; Halverson, Samuel

    2015-12-01

    Extreme radial velocity precisions of order 10cm/s will enable the discoveries of Earth-like planets around solar-type stars. Temperature and pressure variations inside a spectrograph can lead to thermomechanical instabilities in the optics and mounts, and refractive index variations in both the optical elements as well as the surrounding air. Together, these variations can easily induce instrumental drifts of several tens to hundreds of meters per second. Enclosing the full optical train in thermally stabilized high-vacuum environments minimizes such errors. In this talk, I will discuss the Environmental Control System (ECS) for the Habitable Zone Planet Finder (HPF) spectrograph: a near infrared (NIR) facility class instrument we will commission at the Hobby Eberly Telescope in 2016. The ECS will maintain the HPF optical bench stable at 180K at the sub milli-Kelvin level on the timescale of days, and at the few milli-Kelvin level over months to years. The entire spectrograph is kept under high-quality vacuum (controlled radiation shield outfitted with custom feedback electronics. High efficiency Multi-Layer Insulation (MLI) blankets, and a passive external thermal enclosure further isolate the optics from ambient perturbations. This environmental control scheme is versatile, suitable to stabilize both next generation NIR, and optical spectrographs. I will show how we are currently testing this control system for use with our design concept of the Extreme Precision Doppler Spectrograph (EPDS), the next generation optical spectrograph for the WIYN 3.5m telescope. Our most recent results from full-scale stability tests will be presented.

  8. Brushless DC motor control system responsive to control signals generated by a computer or the like

    Science.gov (United States)

    Packard, Douglas T. (Inventor); Schmitt, Donald E. (Inventor)

    1987-01-01

    A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The rotor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor may be regulated by applying a separate control signal to each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

  9. Brushless DC motor control system responsive to control signals generated by a computer or the like

    Science.gov (United States)

    Packard, D. T.

    1985-04-01

    A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The motor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor be regulated by applying a separate control signal and each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

  10. Steam generation process control and automation; Automacao e controle no processo de geracao de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Souza Junior, Jose Cleodon de; Silva, Walmy Andre C.M. da [PETROBRAS S.A., Natal, RN (Brazil)

    2004-07-01

    This paper describes the implementation of the Supervisory Control and Data Acquisition System (SCADA) in the steam generation process for injection in heavy oil fields of the Alto do Rodrigues Production Asset, developed by PETROBRAS/E and P/UN-RNCE. This Asset is located in the northeastern region of Brazil, in Rio Grande do Norte State. It addresses to the steam generators for injection in oil wells and the upgrade project that installed remote terminal units and a new panel controlled by PLC, changed all the pneumatic transmitters by electronic and incorporated the steam quality and oxygen control, providing the remote supervision of the process. It also discusses the improvements obtained in the steam generation after the changes in the conception of the control and safety systems. (author)

  11. Oxygen Generation System Laptop Bus Controller Flight Software

    Science.gov (United States)

    Rowe, Chad; Panter, Donna

    2009-01-01

    The Oxygen Generation System Laptop Bus Controller Flight Software was developed to allow the International Space Station (ISS) program to activate specific components of the Oxygen Generation System (OGS) to perform a checkout of key hardware operation in a microgravity environment, as well as to perform preventative maintenance operations of system valves during a long period of what would otherwise be hardware dormancy. The software provides direct connectivity to the OGS Firmware Controller with pre-programmed tasks operated by on-orbit astronauts to exercise OGS valves and motors. The software is used to manipulate the pump, separator, and valves to alleviate the concerns of hardware problems due to long-term inactivity and to allow for operational verification of microgravity-sensitive components early enough so that, if problems are found, they can be addressed before the hardware is required for operation on-orbit. The decision was made to use existing on-orbit IBM ThinkPad A31p laptops and MIL-STD-1553B interface cards as the hardware configuration. The software at the time of this reporting was developed and tested for use under the Windows 2000 Professional operating system to ensure compatibility with the existing on-orbit computer systems.

  12. A polynomial-based trajectory generator for improved telescope control

    Science.gov (United States)

    Smith, David R.; Souccar, Kamal

    2008-08-01

    For any telescope, a fundamental performance requirement is the acquisition and tracking of the source. While this depends on many factors, the system accuracy is fundamentally limited by the servo tracking performance on the encoders. This tracking performance must be balanced with the need for large slewing motions to new sources. While the classical rate loop and position loop model permits basic operation, there has been increasing use through the years of gain scheduling or command pre-processors to improve telescope path planning and enable better performance. This is particularly important for telescopes that employ scanning or fast switching motions. As telescope control systems have moved to fully digital systems running at high update rates, more sophisticated approaches have become possible for telescope path planning. Taking advantage of the speed of available computation, we have developed a new real time trajectory generator that provides improved performance over previous implementations. Given a position command, the system generates a path to the desired end point. The resulting path is guaranteed to be continuous in position, velocity, and acceleration, as well as to respect specified limits in velocity, acceleration, and jerk. Significantly, the calculation provides not only the desired position over the interval, but also the velocity and acceleration, permitting their use in feedforward control to improve the tracking accuracy at all points on the path. The algorithm is presented, as well as some results with the system implemented on a real telescope.

  13. On the application of bezier surfaces for GA-Fuzzy controller design for use in automatic generation control

    CSIR Research Space (South Africa)

    Boesack, CD

    2012-03-01

    Full Text Available Automatic Generation Control (AGC) of large interconnected power systems are typically controlled by a PI or PID type control law. Recently intelligent control techniques such as GA-Fuzzy controllers have been widely applied within the power...

  14. The approach channel control structure at Arrow Lakes Generating Station

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, A. [Columbia Power Corp., Victoria, BC (Canada); Gemperline, G. [Franklin G. DeFazio Inc., Camano Island, WA (United States); Christison, K. [Northwest Hydraulic Consultants Ltd., Vancouver, BC (Canada); Zipparro, V. [MWH Americas Inc., Broomfield, CO (United States)

    2009-07-01

    In 1999, the Columbia Power Corporation partnered with Columbia Basin Trust and Klohn Crippen SNC Lavalin to develop a project to add generation capability to the Arrow Reservoir, the Arrow Lakes Generating Station (ALGS). Construction was completed in the spring of 2002. The hydroelectric development consists of a 185 MW two-unit powerhouse constructed 400 m downstream of the existing dam. Coordinated mathematical and physical model studies were conducted to design a 35 m wide by 9.4 m high approach channel control structure (ACCS) 200 m upstream of the ALGS. The purpose of the ACCS is to control water levels during abnormal and unexpected operations of the powerhouse and prevent uplift of the concrete channel lining. The discharge capacity of the submerged weir was determined by unsteady open channel modelling. Prototype observations following completion of the structure correlated well with simulated behaviour. Analytical methods were used to optimize flow over the ACCS in order to develop design parameters for the structure. The physical model verified potential ACCS impacts on powerhouse performance parameters. It showed that there would be some reduction in uniformity of the intake flow distribution and a small improvement in vorticity. The study also identified operation restrictions, such as discharge, head loss and rate of flow change restrictions. A series of modifications were considered in the design, such as weir location along the approach channel, crest height, shape of the weir, and future operational consideration. The minor increase in head loss resulted in approximately 2 per cent reduction in average annual energy generation. 16 figs.

  15. Generating controllable type-II Weyl points via periodic driving

    Science.gov (United States)

    Bomantara, Raditya Weda; Gong, Jiangbin

    2016-12-01

    Type-II Weyl semimetals are a novel gapless topological phase of matter discovered recently in 2015. Similar to normal (type-I) Weyl semimetals, type-II Weyl semimetals consist of isolated band touching points. However, unlike type-I Weyl semimetals which have a linear energy dispersion around the band touching points forming a three-dimensional (3D) Dirac cone, type-II Weyl semimetals have a tilted conelike structure around the band touching points. This leads to various novel physical properties that are different from type-I Weyl semimetals. In order to study further the properties of type-II Weyl semimetals and perhaps realize them for future applications, generating controllable type-II Weyl semimetals is desirable. In this paper, we propose a way to generate a type-II Weyl semimetal via a generalized Harper model interacting with a harmonic driving field. When the field is treated classically, we find that only type-I Weyl points emerge. However, by treating the field quantum mechanically, some of these type-I Weyl points may turn into type-II Weyl points. Moreover, by tuning the coupling strength, it is possible to control the tilt of the Weyl points and the energy difference between two Weyl points, which makes it possible to generate a pair of mixed Weyl points of type-I and type-II. We also discuss how to physically distinguish these two types of Weyl points in the framework of our model via the Landau level structures in the presence of an artificial magnetic field. The results are of general interest to quantum optics as well as ongoing studies of Floquet topological phases.

  16. Solution to automatic generation control problem using firefly algorithm optimized I(λ)D(µ) controller.

    Science.gov (United States)

    Debbarma, Sanjoy; Saikia, Lalit Chandra; Sinha, Nidul

    2014-03-01

    Present work focused on automatic generation control (AGC) of a three unequal area thermal systems considering reheat turbines and appropriate generation rate constraints (GRC). A fractional order (FO) controller named as I(λ)D(µ) controller based on crone approximation is proposed for the first time as an appropriate technique to solve the multi-area AGC problem in power systems. A recently developed metaheuristic algorithm known as firefly algorithm (FA) is used for the simultaneous optimization of the gains and other parameters such as order of integrator (λ) and differentiator (μ) of I(λ)D(µ) controller and governor speed regulation parameters (R). The dynamic responses corresponding to optimized I(λ)D(µ) controller gains, λ, μ, and R are compared with that of classical integer order (IO) controllers such as I, PI and PID controllers. Simulation results show that the proposed I(λ)D(µ) controller provides more improved dynamic responses and outperforms the IO based classical controllers. Further, sensitivity analysis confirms the robustness of the so optimized I(λ)D(µ) controller to wide changes in system loading conditions and size and position of SLP. Proposed controller is also found to have performed well as compared to IO based controllers when SLP takes place simultaneously in any two areas or all the areas. Robustness of the proposed I(λ)D(µ) controller is also tested against system parameter variations. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Meta-analysis of Randomized Controlled Trials Comparing Clinical Outcomes Between Short Implants and Long Implants with Bone Augmentation Procedure.

    Science.gov (United States)

    Tong, Qingchun; Zhang, Xingwen; Yu, Liming

    The purpose of this meta-analysis was to assess and compare clinical outcomes of short implants versus long implants placed in conjunction with a bone augmentation procedure. The eligible studies were searched from PubMed, Embase, Springer link, and the Cochrane library databases up to 23 January 2015. Prosthesis failures, implant failures, complications, and marginal bone loss were the clinical outcomes measured. The pooled weighted mean difference (WMD) or risk ratios (RRs) and their 95% confidence intervals (CIs) were used to measure the effect size of continuous variables and dichotomous variables, respectively. A random-effects model was performed to assess the effect size. Nine eligible studies including 480 short implants (≤ 8 mm) and 503 long implants (≥ 9.3 mm) were selected for this meta-analysis. Compared with the long-implant group, a notable decrease in the short-implant group was found for complications at the 5-year follow-up (RR = 0.34, 95% CI: 0.15 to 0.79, P .05). Moreover, the results were not obviously changed when stratified by implants placed in the mandible and maxilla. Implants ≤ 8 mm in length are considered to be a suitable alternative treatment when bone height is not adequate for standard implants.

  18. Power Control of Low Frequency AC Transmission Systems Using Cycloconverters with Virtual Synchronous Generator Control

    OpenAIRE

    Achara Pichetjamroen; Toshifumi Ise

    2016-01-01

    This paper is focused on the application of a multi-terminal line-commutated converter-type low frequency AC transmission system (MTLF) using a cycloconverter by applying a new power control scheme for multi-terminal operation. With the virtual synchronous generator (VSG) control scheme, the transmitting power among the multi-terminal system can be accomplished without a communication link for frequency synchronization in each terminal. The details of the proposed control scheme are explained...

  19. Augmented Reality Interfaces for Additive Manufacturing

    DEFF Research Database (Denmark)

    Eiríksson, Eyþór Rúnar; Pedersen, David Bue; Frisvad, Jeppe Revall

    2017-01-01

    This paper explores potential use cases for using augmented reality (AR) as a tool to operate industrial machines. As a baseline we use an additive manufacturing system, more commonly known as a 3D printer. We implement novel augmented interfaces and controls using readily available open source...

  20. Components of a Rice-Oilseed Rape Production System Augmented with Trichoderma sp. Tri-1 Control Sclerotinia sclerotiorum on Oilseed Rape.

    Science.gov (United States)

    Hu, Xiaojia; Roberts, Daniel P; Xie, Lihua; Maul, Jude E; Yu, Changbing; Li, Yinshui; Zhang, Yinbo; Qin, Lu; Liao, Xing

    2015-10-01

    Sclerotinia sclerotiorum causes serious yield losses on many crops throughout the world. A multicomponent treatment that consisted of the residual rice straw remaining after rice harvest and Trichoderma sp. Tri-1 (Tri-1) formulated with the oilseed rape seedcake fertilizer was used in field soil infested with S. sclerotiorum. This treatment resulted in oilseed rape seed yield that was significantly greater than the nontreated control or when the fungicide carbendizem was used in the presence of this pathogen in field trials. Yield data suggested that the rice straw, oilseed rape seedcake, and Tri-1 components of this treatment all contributed incrementally. Similar treatment results were obtained regarding reduction in disease incidence. Slight improvements in yield and disease incidence were detected when this multicomponent treatment was combined with a fungicide spray. Inhibition of sclerotial germination by this multicomponent treatment trended greater than the nontreated control at 90, 120, and 150 days in field studies but was not significantly different from this control. This multicomponent treatment resulted in increased yield relative to the nontreated control in the absence of pathogen in a greenhouse pot study, while the straw alone and the straw plus oilseed rape seedcake treatments did not; suggesting that Tri-1 was capable of promoting growth. Experiments reported here indicate that a treatment containing components of a rice-oilseed rape production system augmented with Tri-1 can control S. sclerotiorum on oilseed rape, be used in integrated strategies containing fungicide sprays for control of this pathogen, and promote plant growth.

  1. Comprehensible visualization for augmented reality.

    Science.gov (United States)

    Kalkofen, Denis; Mendez, Erick; Schmalstieg, Dieter

    2009-01-01

    This article presents interactive visualizations to support the comprehension of spatial relationships between virtual and real world objects for Augmented Reality (AR) applications. To enhance the clarity of such relationships we discuss visualization techniques and their suitability for AR. We apply them on different AR applications with different goals, e.g. in X-Ray vision or in applications which draw a user's attention to an object of interest. We demonstrate how Focus and Context (F+C) visualizations are used to affect the user's perception of hidden or nearby objects by presenting contextual information in the area of augmentation. We discuss the organization and the possible sources of data for visualizations in Augmented Reality and present cascaded and multi level F+C visualizations to address complex, cluttered scenes that are inevitable in real environments. This article also shows filters and tools to interactively control the amount of augmentation. It compares the impact of real world context preserving to a pure virtual and uniform enhancement of these structures for augmentations of real world imagery. Finally this paper discusses the stylization of sparse object representations for AR to improve X-Ray vision.

  2. Internal and ancestral controls of cell-generation times

    Science.gov (United States)

    Kubitschek, H. E.

    1969-01-01

    Lateral and longitudinal correlations between related cells reveal associations between the generation times of cells for an intermediate period /three generations in bacteral cultures/. Generation times of progeny are influenced by nongenetic factors transmitted from their ancestors.

  3. Maximum Energy Extraction Control for Wind Power Generation Systems Based on the Fuzzy Controller

    Science.gov (United States)

    Kamal, Elkhatib; Aitouche, Abdel; Mohammed, Walaa; Sobaih, Abdel Azim

    2016-10-01

    This paper presents a robust controller for a variable speed wind turbine with a squirrel cage induction generator (SCIG). For variable speed wind energy conversion system, the maximum power point tracking (MPPT) is a very important requirement in order to maximize the efficiency. The system is nonlinear with parametric uncertainty and subject to large disturbances. A Takagi-Sugeno (TS) fuzzy logic is used to model the system dynamics. Based on the TS fuzzy model, a controller is developed for MPPT in the presence of disturbances and parametric uncertainties. The proposed technique ensures that the maximum power point (MPP) is determined, the generator speed is controlled and the closed loop system is stable. Robustness of the controller is tested via the variation of model's parameters. Simulation studies clearly indicate the robustness and efficiency of the proposed control scheme compared to other techniques.

  4. A new generation drilling rig: hydraulically powered and computer controlled

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, M.; Angman, P.; Oveson, D. [Tesco Corp., Calgary, AB, (Canada)

    1999-11-01

    Development, testing and operation of a new generation of hydraulically powered and computer controlled drilling rig that incorporates a number of features that enhance functionality and productivity, is described. The rig features modular construction, a large heated common drilling machinery room, permanently-mounted draw works which, along with the permanently installed top drive, significantly reduces rig-up/rig-down time. Also featured are closed and open hydraulic systems and a unique hydraulic distribution manifold. All functions are controlled through a programmable logic controller (PLC), providing almost unlimited interlocks and calculations to increase rig safety and efficiency. Simplified diagnostic routines, remote monitoring and troubleshooting are also part of the system. To date, two rigs are in operation. Performance of both rigs has been rated as `very good`. Little or no operational problems have been experienced; downtime has averaged 0.61 per cent since August 1998 when the the first of the two rigs went into operation. The most important future application for this rig is for use with the casing drilling process which eliminates the need for drill pipe and tripping. It also reduces the drilling time lost due to unscheduled events such as reaming, fishing and taking kicks while tripping. 1 tab., 6 figs.

  5. Computer controlled MHD power consolidation and pulse generation system

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.; Marcotte, K.; Donnelly, M.

    1990-01-01

    The major goal of this research project is to establish the feasibility of a power conversion technology which will permit the direct synthesis of computer programmable pulse power. Feasibility has been established in this project by demonstration of direct synthesis of commercial frequency power by means of computer control. The power input to the conversion system is assumed to be a Faraday connected MHD generator which may be viewed as a multi-terminal dc source and is simulated for the purpose of this demonstration by a set of dc power supplies. This consolidation/inversion (CI), process will be referred to subsequently as Pulse Amplitude Synthesis and Control (PASC). A secondary goal is to deliver a controller subsystem consisting of a computer, software, and computer interface board which can serve as one of the building blocks for a possible phase II prototype system. This report period work summarizes the accomplishments and covers the high points of the two year project. 6 refs., 41 figs.

  6. Mobile Augmented Reality as a Feature for Self-Oriented, Blended Learning in Medicine: Randomized Controlled Trial

    Science.gov (United States)

    2017-01-01

    Background Advantages of mobile Augmented Reality (mAR) application-based learning versus textbook-based learning were already shown in a previous study. However, it was unclear whether the augmented reality (AR) component was responsible for the success of the self-developed app or whether this was attributable to the novelty of using mobile technology for learning. Objective The study’s aim was to test the hypothesis whether there is no difference in learning success between learners who employed the mobile AR component and those who learned without it to determine possible effects of mAR. Also, we were interested in potential emotional effects of using this technology. Methods Forty-four medical students (male: 25, female: 19, mean age: 22.25 years, standard deviation [SD]: 3.33 years) participated in this study. Baseline emotional status was evaluated using the Profile of Mood States (POMS) questionnaire. Dermatological knowledge was ascertained using a single choice (SC) test (10 questions). The students were randomly assigned to learn 45 min with either a mobile learning method with mAR (group A) or without AR (group B). Afterwards, both groups were again asked to complete the previous questionnaires. AttrakDiff 2 questionnaires were used to evaluate the perceived usability as well as pragmatic and hedonic qualities. For capturing longer term effects, after 14 days, all participants were again asked to complete the SC questionnaire. All evaluations were anonymous, and descriptive statistics were calculated. For hypothesis testing, an unpaired signed-rank test was applied. Results For the SC tests, there were only minor differences, with both groups gaining knowledge (average improvement group A: 3.59 [SD 1.48]; group B: 3.86 [SD 1.51]). Differences between both groups were statistically insignificant (exact Mann Whitney U, U=173.5; P=.10; r=.247). However, in the follow-up SC test after 14 days, group A had retained more knowledge (average decrease of the

  7. Mobile Augmented Reality as a Feature for Self-Oriented, Blended Learning in Medicine: Randomized Controlled Trial.

    Science.gov (United States)

    Noll, Christoph; von Jan, Ute; Raap, Ulrike; Albrecht, Urs-Vito

    2017-09-14

    Advantages of mobile Augmented Reality (mAR) application-based learning versus textbook-based learning were already shown in a previous study. However, it was unclear whether the augmented reality (AR) component was responsible for the success of the self-developed app or whether this was attributable to the novelty of using mobile technology for learning. The study's aim was to test the hypothesis whether there is no difference in learning success between learners who employed the mobile AR component and those who learned without it to determine possible effects of mAR. Also, we were interested in potential emotional effects of using this technology. Forty-four medical students (male: 25, female: 19, mean age: 22.25 years, standard deviation [SD]: 3.33 years) participated in this study. Baseline emotional status was evaluated using the Profile of Mood States (POMS) questionnaire. Dermatological knowledge was ascertained using a single choice (SC) test (10 questions). The students were randomly assigned to learn 45 min with either a mobile learning method with mAR (group A) or without AR (group B). Afterwards, both groups were again asked to complete the previous questionnaires. AttrakDiff 2 questionnaires were used to evaluate the perceived usability as well as pragmatic and hedonic qualities. For capturing longer term effects, after 14 days, all participants were again asked to complete the SC questionnaire. All evaluations were anonymous, and descriptive statistics were calculated. For hypothesis testing, an unpaired signed-rank test was applied. For the SC tests, there were only minor differences, with both groups gaining knowledge (average improvement group A: 3.59 [SD 1.48]; group B: 3.86 [SD 1.51]). Differences between both groups were statistically insignificant (exact Mann Whitney U, U=173.5; P=.10; r=.247). However, in the follow-up SC test after 14 days, group A had retained more knowledge (average decrease of the number of correct answers group A: 0

  8. Aspects of User Experience in Augmented Reality

    DEFF Research Database (Denmark)

    Madsen, Jacob Boesen

    In Augmented Reality applications, the real environment is annotated or enhanced with computer-generated graphics. This is a topic that has been researched in the recent decades, but for many people this is a brand new and never heard of topic. The main focus of this thesis is investigations...... in human factors related to Augmented Reality. This is investigated partly as how Augmented Reality applications are used in unsupervised settings, and partly in specific evaluations related to user performance in supervised settings. The thesis starts by introducing Augmented Reality to the reader......, followed by a presentation of the technical areas related to the field, and different human factor areas. As a contribution to the research area, this thesis presents five separate, but sequential, papers within the area of Augmented Reality....

  9. Effects of the hippocampus on the motor expression of augmented breaths.

    Directory of Open Access Journals (Sweden)

    Itopa E Ajayi

    Full Text Available Augmented breaths, also known as sighs, constitute the normal repertoire of breathing in freely behaving humans and animals. The breaths are believed to be generated by neurones in the preBötzinger complex but under modulatory influence from higher brain centres, particularly in the limbic system due to the strong correlations between the expression of emotional behaviours such as anxiety and the occurrence of augmented breaths. The current study examines the role of the hippocampus in the motor expression of augmented breaths, and also examines the characteristics of eupneic breaths surrounding a sigh before and after stimulating the hippocampus in urethane anaesthetised Sprague-Dawley rats. Neurochemical microstimulation using the excitatory amino acid, D,L-Homocysteic acid, was used to locate areas in the hippocampus with the potential to modulated the motor expression of augmented breaths. The CA1 neurone cluster of the ventral hippocampus was found to completely suppress the expression of augmented breaths without affecting the intrinsic properties of the breaths. A similar neurone cluster, but in the dorsal field of the hippocampus, was also investigated and found to have no effects over the expression of augmented breaths. The data supports the hypothesis that there is a structural or functional relationship between neurones of the ventral hippocampus and brainstem nuclei that control augmented breaths. The implications of these findings in the context of behaviours are discussed but with due consideration of experimental conditions.

  10. Experimental Investigation of Augmented Spark Ignition of a LO2/LCH4 Reaction Control Engine at Altitude Conditions

    Science.gov (United States)

    Kleinhenz, Julie; Sarmiento, Charles; Marshall, William

    2012-01-01

    The use of nontoxic propellants in future exploration vehicles would enable safer, more cost-effective mission scenarios. One promising green alternative to existing hypergols is liquid methane (LCH4) with liquid oxygen (LO2). A 100 lbf LO2/LCH4 engine was developed under the NASA Propulsion and Cryogenic Advanced Development project and tested at the NASA Glenn Research Center Altitude Combustion Stand in a low pressure environment. High ignition energy is a perceived drawback of this propellant combination; so this ignition margin test program examined ignition performance versus delivered spark energy. Sensitivity of ignition to spark timing and repetition rate was also explored. Three different exciter units were used with the engine s augmented (torch) igniter. Captured waveforms indicated spark behavior in hot fire conditions was inconsistent compared to the well-behaved dry sparks. This suggests that rising pressure and flow rate increase spark impedance and may at some point compromise an exciter s ability to complete each spark. The reduced spark energies of such quenched deliveries resulted in more erratic ignitions, decreasing ignition probability. The timing of the sparks relative to the pressure/flow conditions also impacted the probability of ignition. Sparks occurring early in the flow could trigger ignition with energies as low as 1 to 6 mJ, though multiple, similarly timed sparks of 55 to 75 mJ were required for reliable ignition. Delayed spark application and reduced spark repetition rate both correlated with late and occasional failed ignitions. An optimum time interval for spark application and ignition therefore coincides with propellant introduction to the igniter.

  11. Steam generator degradation: Current mitigation strategies for controlling corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Millett, P. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-02-01

    Steam Generator degradation has caused substantial losses of power generation, resulted in large repair and maintenance costs, and contributed to significant personnel radiation exposures in Pressurized Water Reactors (PWRs) operating throughout the world. EPRI has just published the revised Steam Generator Reference Book, which reviews all of the major forms of SG degradation. This paper discusses the types of SG degradation that have been experienced with emphasis on the mitigation strategies that have been developed and implemented in the field. SG degradation is presented from a world wide perspective as all countries operating PWRs have been effected to one degree or another. The paper is written from a US. perspective where the utility industry is currently undergoing tremendous change as a result of deregulation of the electricity marketplace. Competitive pressures are causing utilities to strive to reduce Operations and Maintenance (O&M) and capital costs. SG corrosion is a major contributor to the O&M costs of PWR plants, and therefore US utilities are evaluating and implementing the most cost effective solutions to their corrosion problems. Mitigation strategies developed over the past few years reflect a trend towards plant specific solutions to SG corrosion problems. Since SG degradation is in most cases an economic problem and not a safety problem, utilities can focus their mitigation strategies on their unique financial situation. Accordingly, the focus of R&D has shifted from the development of more expensive, prescriptive solutions (e.g. reduced impurity limits) to corrosion problems to providing the utilities with a number of cost effective mitigation options (e.g. molar ratio control, boric acid treatment).

  12. Designing hybrid grass genomes to control runoff generation

    Science.gov (United States)

    MacLeod, C.; Binley, A.; Humphreys, M.; King, I. P.; O'Donovan, S.; Papadopoulos, A.; Turner, L. B.; Watts, C.; Whalley, W. R.; Haygarth, P.

    2010-12-01

    Sustainable management of water in landscapes requires balancing demands of agricultural production whilst moderating downstream effects like flooding. Pasture comprises 69% of global agricultural areas and is essential for producing food and fibre alongside environmental goods and services. Thus there is a need to breed forage grasses that deliver multiple benefits through increased levels of productivity whilst moderating fluxes of water. Here we show that a novel grass hybrid that combines the entire genomes of perennial ryegrass (Lolium perenne - the grass of choice for Europe’s forage agriculture) and meadow fescue (Festuca pratensis) has a significant role in flood prevention. Field plot experiments established differences in runoff generation with the hybrid cultivar reducing runoff by 50% compared to perennial ryegrass cultivar, and by 35% compared to a meadow fescue cultivar (34 events over two years, replicated randomized-block design, statistically significant differences). This important research outcome was the result of a project that combined plant genetics, soil physics and plot scale hydrology to identify novel grass genotypes that can reduce runoff from grassland systems. Through a coordinated series of experiments examining effects from the gene to plot scale, we have identified that the rapid growth and then turnover of roots in the L. perenne x F. pratensis hybrid is likely to be a key mechanism in reducing runoff generation. More broadly this is an exciting first step to realizing the potential to design grass genomes to achieve both food production, and to deliver flood control, a key ecosystem service.

  13. Anonymous Authorship Control for User-Generated Content

    Directory of Open Access Journals (Sweden)

    Suk-Bong LEE

    2007-12-01

    Full Text Available User-Generated Content (UGC is opening up new large market in content services, and more and more people are visiting web sites to share and enjoy UGCs. These trends make many authors to move into online. Authors want to conserve their authorship and expect to publish their UGC anonymously in cases. To meet the requirements, we propose a new authorship control model based on watermarking and metadata. Authors can embed their authorship into their UGC with identities or with anonym. Even though an author publishes his UGC anonymously, he can prove his authorship without unveiling his identity via 5 methods utilizing the proposed authorship model. The proposed model and methods need no TTP and are robust even based on fragile underlying watermarking scheme.

  14. Timing reference generators and chopper controllers for neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.; Merl, R.; Rose, C. [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2001-03-01

    Due to AC-power-grid frequency fluctuations, the designers for accelerator-based spallation-neutron facilities have worked to optimize the competing and contrasting demands of accelerator and neutron chopper performance. Powerful new simulation techniques have enabled the modeling of the timing systems that integrate chopper controllers and chopper hardware. For the first time, we are able to quantitatively access the tradeoffs between these two constraints and design or upgrade a facility to optimize total system performance. Thus, at LANSCE, we now operate multiple chopper systems and the accelerator as simple slaves to a single master-timing-reference generator. For the SNS we recommend a similar system that is somewhat less tightly coupled to the power grid. (author)

  15. Solar Photovoltaic (PV) Distributed Generation Systems - Control and Protection

    Science.gov (United States)

    Yi, Zhehan

    This dissertation proposes a comprehensive control, power management, and fault detection strategy for solar photovoltaic (PV) distribution generations. Battery storages are typically employed in PV systems to mitigate the power fluctuation caused by unstable solar irradiance. With AC and DC loads, a PV-battery system can be treated as a hybrid microgrid which contains both DC and AC power resources and buses. In this thesis, a control power and management system (CAPMS) for PV-battery hybrid microgrid is proposed, which provides 1) the DC and AC bus voltage and AC frequency regulating scheme and controllers designed to track set points; 2) a power flow management strategy in the hybrid microgrid to achieve system generation and demand balance in both grid-connected and islanded modes; 3) smooth transition control during grid reconnection by frequency and phase synchronization control between the main grid and microgrid. Due to the increasing demands for PV power, scales of PV systems are getting larger and fault detection in PV arrays becomes challenging. High-impedance faults, low-mismatch faults, and faults occurred in low irradiance conditions tend to be hidden due to low fault currents, particularly, when a PV maximum power point tracking (MPPT) algorithm is in-service. If remain undetected, these faults can considerably lower the output energy of solar systems, damage the panels, and potentially cause fire hazards. In this dissertation, fault detection challenges in PV arrays are analyzed in depth, considering the crossing relations among the characteristics of PV, interactions with MPPT algorithms, and the nature of solar irradiance. Two fault detection schemes are then designed as attempts to address these technical issues, which detect faults inside PV arrays accurately even under challenging circumstances, e.g., faults in low irradiance conditions or high-impedance faults. Taking advantage of multi-resolution signal decomposition (MSD), a powerful signal

  16. Polymeric dispersants for control of steam generator fouling

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, P.V.; Klimas, S.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Lepine, L. [Institut de Recherche d' Hydro-Quebec, Varennes, Quebec (Canada); Turner, C.W

    1999-05-01

    Fouling of steam generators by corrosion products from the feedtrain leads to loss of heat-transfer efficiency, disturbances in thermalhydraulics, and potential corrosion problems resulting from the development of sites for localized accumulation of aggressive chemicals. This report summarizes studies of the use of polymeric dispersants for the control of fouling, which were conducted at the Chalk River Laboratories. High-temperaturesettling studies on magnetite suspensions were performed to screen available generic dispersants, and the dispersants were ranked in terms of their dispersion efficiency; polyacrylic acid (PAA) and the phosphonate, HEDP, were ranked as the most efficient. Polyacrylic acid was considered more suitable than HEDP for nuclear steam generators, and more emphasis was given to the former in these studies. The dispersants had no effect on the particle deposition rates under single-phase forced-convective flow, but did reduce the deposition rates under flow-boiling conditions. The extent to which the deposition rates were reduced increased in proportion to the dispersant concentration. Preliminary corrosion tests indicated that pitting or general corrosion of steam generator tube materials in the presence of PAA was negligible. Corrosion of carbon steel, although higher in a magnetite-packed crevice under heat flux than in bulk water, was lower in the presence of PAA than in its absence. Some impurities (e.g., sulphate, sodium) were observed in commercially available PAA products at small, though significant concentrations, making these products unacceptable for use in nuclear plants. However, the PAA could be purified by ion exchange. Preliminary experiments, to assess the thermal stability of PAA at steam generator operating temperature, showed the polymer to break down in deaerated solutions and under argon cover to give hydrogen and carbon dioxide as the two major products in the gas phase and variable concentrations of acetate and formate

  17. Automatic generation control with thyristor controlled series compensator including superconducting magnetic energy storage units

    Directory of Open Access Journals (Sweden)

    Saroj Padhan

    2014-09-01

    Full Text Available In the present work, an attempt has been made to understand the dynamic performance of Automatic Generation Control (AGC of multi-area multi-units thermal–thermal power system with the consideration of Reheat turbine, Generation Rate Constraint (GRC and Time delay. Initially, the gains of the fuzzy PID controller are optimized using Differential Evolution (DE algorithm. The superiority of DE is demonstrated by comparing the results with Genetic Algorithm (GA. After that performance of Thyristor Controlled Series Compensator (TCSC has been investigated. Further, a TCSC is placed in the tie-line and Superconducting Magnetic Energy Storage (SMES units are considered in both areas. Finally, sensitivity analysis is performed by varying the system parameters and operating load conditions from their nominal values. It is observed that the optimum gains of the proposed controller need not be reset even if the system is subjected to wide variation in loading condition and system parameters.

  18. Augmented reality system

    Science.gov (United States)

    Lin, Chien-Liang; Su, Yu-Zheng; Hung, Min-Wei; Huang, Kuo-Cheng

    2010-08-01

    In recent years, Augmented Reality (AR)[1][2][3] is very popular in universities and research organizations. The AR technology has been widely used in Virtual Reality (VR) fields, such as sophisticated weapons, flight vehicle development, data model visualization, virtual training, entertainment and arts. AR has characteristics to enhance the display output as a real environment with specific user interactive functions or specific object recognitions. It can be use in medical treatment, anatomy training, precision instrument casting, warplane guidance, engineering and distance robot control. AR has a lot of vantages than VR. This system developed combines sensors, software and imaging algorithms to make users feel real, actual and existing. Imaging algorithms include gray level method, image binarization method, and white balance method in order to make accurate image recognition and overcome the effects of light.

  19. Augmentation-related brain plasticity

    Science.gov (United States)

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self

  20. AUGMENTATION-RELATED BRAIN PLASTICITY

    Directory of Open Access Journals (Sweden)

    Giovanni eDi Pino

    2014-06-01

    Full Text Available Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyzes the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain.Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools.Augmentation modifies function and structure of a number of areas, i.e. primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the

  1. Efficacy of risperidone augmentation to antidepressants in the management of suicidality in major depressive disorder: a randomized, double-blind, placebo-controlled pilot study.

    Science.gov (United States)

    Reeves, Hollis; Batra, Sachin; May, Roberta S; Zhang, Rusheng; Dahl, Daniel C; Li, Xiaohua

    2008-08-01

    Major depressive disorder (MDD) is a severe mental illness with high risk of suicidality. Antidepressant treatment alone is not sufficient for the acute management of risk-taking symptoms of depression. This pilot study was designed to investigate the efficacy of risperidone augmentation to antidepressants in the acute management of suicidality and other core symptoms in MDD with suicidality. Twenty-four adult men and women diagnosed with MDD (DSM-IV), having a depressive episode with suicidality despite taking an antidepressant, were enrolled in an 8-week double-blind, placebo-controlled study. Subjects were randomly assigned to receive risperidone (0.25-2 mg/day) or placebo while continuing on their antidepressant therapy. Clinical efficacy in suicidality, depressive symptoms, and impulsivity were assessed after treatment with study drugs for 4 days, weekly for 4 weeks, then every other week for 4 weeks. Adverse events were also recorded at each visit. The study was conducted from June 2004 to April 2007. Risperidone significantly reduced suicidal ideations in MDD patients, and the overall effect of risperidone appeared to be superior to placebo. The effect of risperidone was rapid, with onset at 2 weeks' treatment, and was sustained along the course of 8 weeks' treatment. Furthermore, risperidone demonstrated superiority to placebo in improving other symptoms related to suicidality and having better trial completion rate, and the low dose risperidone was well tolerated by subjects in this study. Data from this pilot study suggest that risperidone is beneficial as an augmenting treatment in MDD patients who have developed high-risk suicidal ideation during a depressive episode. The antisuicidality effect of risperidone is especially valuable in the acute management of severe depressive symptoms. Although the pilot study is limited by small sample size, the promising results warrant further larger scale investigation in the efficacy of atypical antipsychotics in

  2. Confronting an augmented reality

    OpenAIRE

    John Hedberg; Robert Fitzgerald; James Steele; Anna Wilson; Matt Bacon; Danny Munnerley

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and suggest that they be used as drivers for research into effective educational applications of augmented reality. We discuss how multi-modal, sensorial...

  3. Are gender differences in upper-body power generated by elite cross-country skiers augmented by increasing the intensity of exercise?

    Directory of Open Access Journals (Sweden)

    Ann Magdalen Hegge

    Full Text Available In the current study, we evaluated the impact of exercise intensity on gender differences in upper-body poling among cross-country skiers, as well as the associated differences in aerobic capacity, maximal strength, body composition, technique and extent of training. Eight male and eight female elite skiers, gender-matched for level of performance by FIS points, carried out a 4-min submaximal, and a 3-min and 30-sec maximal all-out test of isolated upper-body double poling on a Concept2 ski ergometer. Maximal upper-body power and strength (1RM were determined with a pull-down exercise. In addition, body composition was assessed with a DXA scan and training during the previous six months quantified from diaries. Relative to the corresponding female values (defined as 100%, the power output produced by the men was 88%, 95% and 108% higher during the submaximal, 3-min and 30-sec tests, respectively, and peak power in the pull-down strength exercise was 118% higher (all P<0.001. During the ergometer tests the work performed per cycle by the men was 97%, 102% and 91% greater, respectively, and the men elevated their cycle rate to a greater extent at higher intensities (both P<0.01. Furthermore, men had a 61% higher VO2peak, 58% higher 1RM, relatively larger upper-body mass (61% vs 56% and reported considerably more upper-body strength and endurance training (all P<0.05. In conclusion, gender differences in upper-body power among cross-country skiers augmented as the intensity of exercise increased. The gender differences observed here are greater than those reported previously for both lower- and whole-body sports and coincided with greater peak aerobic capacity and maximal upper-body strength, relatively more muscle mass in the upper-body, and more extensive training of upper-body strength and endurance among the male skiers.

  4. V-TIME: a treadmill training program augmented by virtual reality to decrease fall risk in older adults: study design of a randomized controlled trial.

    Science.gov (United States)

    Mirelman, Anat; Rochester, Lynn; Reelick, Miriam; Nieuwhof, Freek; Pelosin, Elisa; Abbruzzese, Giovanni; Dockx, Kim; Nieuwboer, Alice; Hausdorff, Jeffrey M

    2013-02-06

    Recent work has demonstrated that fall risk can be attributed to cognitive as well as motor deficits. Indeed, everyday walking in complex environments utilizes executive function, dual tasking, planning and scanning, all while walking forward. Pilot studies suggest that a multi-modal intervention that combines treadmill training to target motor function and a virtual reality obstacle course to address the cognitive components of fall risk may be used to successfully address the motor-cognitive interactions that are fundamental for fall risk reduction. The proposed randomized controlled trial will evaluate the effects of treadmill training augmented with virtual reality on fall risk. Three hundred older adults with a history of falls will be recruited to participate in this study. This will include older adults (n=100), patients with mild cognitive impairment (n=100), and patients with Parkinson's disease (n=100). These three sub-groups will be recruited in order to evaluate the effects of the intervention in people with a range of motor and cognitive deficits. Subjects will be randomly assigned to the intervention group (treadmill training with virtual reality) or to the active-control group (treadmill training without virtual reality). Each person will participate in a training program set in an outpatient setting 3 times per week for 6 weeks. Assessments will take place before, after, and 1 month and 6 months after the completion of the training. A falls calendar will be kept by each participant for 6 months after completing the training to assess fall incidence (i.e., the number of falls, multiple falls and falls rate). In addition, we will measure gait under usual and dual task conditions, balance, community mobility, health related quality of life, user satisfaction and cognitive function. This randomized controlled trial will demonstrate the extent to which an intervention that combines treadmill training augmented by virtual reality reduces fall risk

  5. Informatics in radiology: Intuitive user interface for 3D image manipulation using augmented reality and a smartphone as a remote control.

    Science.gov (United States)

    Nakata, Norio; Suzuki, Naoki; Hattori, Asaki; Hirai, Naoya; Miyamoto, Yukio; Fukuda, Kunihiko

    2012-01-01

    Although widely used as a pointing device on personal computers (PCs), the mouse was originally designed for control of two-dimensional (2D) cursor movement and is not suited to complex three-dimensional (3D) image manipulation. Augmented reality (AR) is a field of computer science that involves combining the physical world and an interactive 3D virtual world; it represents a new 3D user interface (UI) paradigm. A system for 3D and four-dimensional (4D) image manipulation has been developed that uses optical tracking AR integrated with a smartphone remote control. The smartphone is placed in a hard case (jacket) with a 2D printed fiducial marker for AR on the back. It is connected to a conventional PC with an embedded Web camera by means of WiFi. The touch screen UI of the smartphone is then used as a remote control for 3D and 4D image manipulation. Using this system, the radiologist can easily manipulate 3D and 4D images from computed tomography and magnetic resonance imaging in an AR environment with high-quality image resolution. Pilot assessment of this system suggests that radiologists will be able to manipulate 3D and 4D images in the reading room in the near future. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.324115086/-/DC1.

  6. Microfluidic droplet generator with controlled break-up mechanism

    KAUST Repository

    Gonzalez, David Conchouso

    2017-04-13

    Droplet generation devices and systems that parallelize droplet generation devices are provided. The droplet generation devices can include a symmetric block-and-break system and a tapered droplet generation zone. The symmetric block-and-break system can include a pair of break channels and a pair of bypass channels symmetrically arranged with respect to the dispersed-phase input channel and the output channel. The droplet generation devices can generate monodisperse droplets with a predefined volume over a range of flow rates, pressures, and fluid properties. The droplet generation devices are therefore capable of parallelization to achieve large-capacity droplet generation, e.g. greater than 1 L/hr, with small overall coefficients of variation.

  7. An Experimental Evaluation of Generalized Predictive Control for Tiltrotor Aeroelastic Stability Augmentation in Airplane Mode of Flight

    Science.gov (United States)

    Kvaternik, Raymond G.; Piatak, David J.; Nixon, Mark W.; Langston, Chester W.; Singleton, Jeffrey D.; Bennett, Richard L.; Brown, Ross K.

    2001-01-01

    The results of a joint NASA/Army/Bell Helicopter Textron wind-tunnel test to assess the potential of Generalized Predictive Control (GPC) for actively controlling the swashplate of tiltrotor aircraft to enhance aeroelastic stability in the airplane mode of flight are presented. GPC is an adaptive time-domain predictive control method that uses a linear difference equation to describe the input-output relationship of the system and to design the controller. The test was conducted in the Langley Transonic Dynamics Tunnel using an unpowered 1/5-scale semispan aeroelastic model of the V-22 that was modified to incorporate a GPC-based multi-input multi-output control algorithm to individually control each of the three swashplate actuators. Wing responses were used for feedback. The GPC-based control system was highly effective in increasing the stability of the critical wing mode for all of the conditions tested, without measurable degradation of the damping in the other modes. The algorithm was also robust with respect to its performance in adjusting to rapid changes in both the rotor speed and the tunnel airspeed.

  8. Studies of Next Generation Air Traffic Control Specialists: Why Be an Air Traffic Controller?

    Science.gov (United States)

    2011-08-01

    example, the job security and stability that appealed to “ Baby Boomers ” might be less important to “Gen-X” and “ Millennials ,” who are said to be looking...controllers, recruited from Gen-X and Millennials , than to the “Post-Strike” generation (largely Baby Boomers ) and non-material factors such as the...air traffic coNtrol SpecialiStS: Why Be aN air traffic coNtroller? “Gen-X,” “Gen-Y,” “ Baby Boomer ,” “ Millennial ,” “The Greatest Generation”: Labels

  9. Thrust augmentation for a small turbojet engine

    OpenAIRE

    Hackaday, Gary L.

    1999-01-01

    Approved for public release; distribution is unlimited A Sophia J450 (nine pounds of thrust) gas turbine engine was used first to examine the thrust augmentation generated using an ejector shroud. Experimental results obtained with and without the ejector were compared with performance predicted using an engine code and a one-dimensional ejector analysis. The engine code was revised to incorporate a radial turbine and the correct compressor map. Thrust augmentation of 3-10% was measured an...

  10. COMMAND AND CONTROL STRATEGIES APPLIED TO HIGHPOWER STEAM GENERATORS

    Directory of Open Access Journals (Sweden)

    DUINEA. A.M.

    2015-06-01

    Full Text Available The paper presents the analysis of the actual operation scheme existing for steam generator drum. Following the trend valid for forced circulation steam generator, it is proposed to replace the classical adjustment loops with new regulation scheme highlighting its advantages in steam generation operation.

  11. power generation and control of a self excited squirrel cage ...

    African Journals Online (AJOL)

    HOD

    generator. The possibility of using a capacitor bank connected across the stator terminals of a squirrel cage induction motor to supply the reactive power requirement for power generation was discovered by. Basset and Potter in the 1930s It is more attractive than a conventional synchronous generator in micro- hydro and ...

  12. Microgrids and distributed generation systems: Control, operation, coordination and planning

    Science.gov (United States)

    Che, Liang

    Distributed Energy Resources (DERs) which include distributed generations (DGs), distributed energy storage systems, and adjustable loads are key components in microgrid operations. A microgrid is a small electric power system integrated with on-site DERs to serve all or some portion of the local load and connected to the utility grid through the point of common coupling (PCC). Microgrids can operate in both grid-connected mode and island mode. The structure and components of hierarchical control for a microgrid at Illinois Institute of Technology (IIT) are discussed and analyzed. Case studies would address the reliable and economic operation of IIT microgrid. The simulation results of IIT microgrid operation demonstrate that the hierarchical control and the coordination strategy of distributed energy resources (DERs) is an effective way of optimizing the economic operation and the reliability of microgrids. The benefits and challenges of DC microgrids are addressed with a DC model for the IIT microgrid. We presented the hierarchical control strategy including the primary, secondary, and tertiary controls for economic operation and the resilience of a DC microgrid. The simulation results verify that the proposed coordinated strategy is an effective way of ensuring the resilient response of DC microgrids to emergencies and optimizing their economic operation at steady state. The concept and prototype of a community microgrid that interconnecting multiple microgrids in a community are proposed. Two works are conducted. For the coordination, novel three-level hierarchical coordination strategy to coordinate the optimal power exchanges among neighboring microgrids is proposed. For the planning, a multi-microgrid interconnection planning framework using probabilistic minimal cut-set (MCS) based iterative methodology is proposed for enhancing the economic, resilience, and reliability signals in multi-microgrid operations. The implementation of high-reliability microgrids

  13. Facilitation of fear extinction in phobic participants with a novel cognitive enhancer: A randomized placebo controlled trial of yohimbine augmentation

    NARCIS (Netherlands)

    Powers, M.B.; Smits, J.A.J.; Otto, M.W.; Sanders, C.; Emmelkamp, P.M.G.

    2009-01-01

    Preliminary animal research suggests that yohimbine hydrochloride, a selective competitive alpha2-adrenergic receptor antagonist, accelerates fear extinction and converts ineffective extinction regimens (long intertrial intervals) to effective ones. This randomized placebo controlled study examined

  14. Facilitation of fear extinction in phobic participants with a novel cognitive enhancer: a randomized placebo controlled trial of yohimbine augmentation

    NARCIS (Netherlands)

    Powers, M.B.; Smits, J.A.J.; Otto, M.W.; Sanders, C.; Emmelkamp, P.M.G.

    2009-01-01

    Preliminary animal research suggests that yohimbine hydrochloride, a selective competitive alpha2-adrenergic receptor antagonist, accelerates fear extinction and converts ineffective extinction regimens (long intertrial intervals) to effective ones. This randomized placebo controlled study examined

  15. Making Self-Help More Helpful: A Randomized Controlled Trial of the Impact of Augmenting Self-Help Materials with Implementation Intentions on Promoting the Effective Self-Management of Anxiety Symptoms

    Science.gov (United States)

    Varley, Rachel; Webb, Thomas L.; Sheeran, Paschal

    2011-01-01

    Objective: The effectiveness of self-help materials may be constrained by failures to undertake recommended exercises or to deploy the techniques that one has learned at the critical moment. The present randomized controlled trial investigated whether augmenting self-help materials with if-then plans (or implementation intentions) could overcome…

  16. Dual-loop self-optimizing robust control of wind power generation with Doubly-Fed Induction Generator.

    Science.gov (United States)

    Chen, Quan; Li, Yaoyu; Seem, John E

    2015-09-01

    This paper presents a self-optimizing robust control scheme that can maximize the power generation for a variable speed wind turbine with Doubly-Fed Induction Generator (DFIG) operated in Region 2. A dual-loop control structure is proposed to synergize the conversion from aerodynamic power to rotor power and the conversion from rotor power to the electrical power. The outer loop is an Extremum Seeking Control (ESC) based generator torque regulation via the electric power feedback. The ESC can search for the optimal generator torque constant to maximize the rotor power without wind measurement or accurate knowledge of power map. The inner loop is a vector-control based scheme that can both regulate the generator torque requested by the ESC and also maximize the conversion from the rotor power to grid power. An ℋ(∞) controller is synthesized for maximizing, with performance specifications defined based upon the spectrum of the rotor power obtained by the ESC. Also, the controller is designed to be robust against the variations of some generator parameters. The proposed control strategy is validated via simulation study based on the synergy of several software packages including the TurbSim and FAST developed by NREL, Simulink and SimPowerSystems. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Control and characterization of a bistable laminate generated with piezoelectricity

    Science.gov (United States)

    Lee, Andrew J.; Moosavian, Amin; Inman, Daniel J.

    2017-08-01

    Extensive research has been conducted on utilizing smart materials such as piezoelectric and shape memory alloy actuators to induce snap through of bistable structures for morphing applications. However, there has only been limited success in initiating snap through from both stable states due to the lack of actuation authority. A novel solution in the form of a piezoelectrically generated bistable laminate consisting of only macro fiber composites (MFC), allowing complete configuration control without any external assistance, is explored in detail here. Specifically, this paper presents the full analytical, computational, and experimental results of the laminate’s design, geometry, bifurcation behavior, and snap through capability. By bonding two actuated MFCs in a [0MFC/90MFC]T layup and releasing the voltage post cure, piezoelectric strain anisotropy and the resulting in-plane residual stresses yield two statically stable states that are cylindrically shaped. The analytical model uses the Rayleigh-Ritz minimization of total potential energy and finite element analysis is implemented in MSC Nastran. The [0MFC/90MFC]T laminate is then manufactured and experimentally characterized for model validation. This paper demonstrates the adaptive laminate’s unassisted forward and reverse snap through capability enabled by the efficiencies gained from simultaneously being the actuator and the primary structure.

  18. Corrosion Evaluation and Corrosion Control of Steam Generators

    Energy Technology Data Exchange (ETDEWEB)

    Maeng, W. Y.; Kim, U. C.; Sung, K. W.; Na, J. W.; Lee, Y. H.; Lee, D. H.; Kim, K. M

    2008-06-15

    Corrosion damage significantly influences the integrity and efficiency of steam generator. Corrosion problems of steam generator are unsolved issues until now even though much effort is made around world. Especially the stress corrosion cracking of heat exchange materials is the first issue to be solved. The corrosion protection method of steam generator is important and urgent for the guarantee of nuclear plant's integrity. The objectives of this study are 1) to evaluate the corrosion properties of steam generator materials, 2) to optimize the water chemistry of steam generator and 3) to develop the corrosion protection method of primary and secondary sides of steam generator. The results will be reflected to the water chemistry guideline for improving the integrity and efficiency of steam generator in domestic power plants.

  19. Infusing CD19-directed T cells to augment disease control in patients undergoing autologous hematopoietic stem-cell transplantation for advanced B-lymphoid malignancies.

    Science.gov (United States)

    Kebriaei, Partow; Huls, Helen; Jena, Bipulendu; Munsell, Mark; Jackson, Rineka; Lee, Dean A; Hackett, Perry B; Rondon, Gabriela; Shpall, Elizabeth; Champlin, Richard E; Cooper, Laurence J N

    2012-05-01

    Limited curative treatment options exist for patients with advanced B-lymphoid malignancies, and new therapeutic approaches are needed to augment the efficacy of hematopoietic stem-cell transplantation (HSCT). Cellular therapies, such as adoptive transfer of T cells that are being evaluated to target malignant disease, use mechanisms independent of chemo- and radiotherapy with nonoverlapping toxicities. Gene therapy is employed to generate tumor-specific T cells, as specificity can be redirected through enforced expression of a chimeric antigen receptor (CAR) to achieve antigen recognition based on the specificity of a monoclonal antibody. By combining cell and gene therapies, we have opened a new Phase I protocol at the MD Anderson Cancer Center (Houston, TX) to examine the safety and feasibility of administering autologous genetically modified T cells expressing a CD19-specific CAR (capable of signaling through chimeric CD28 and CD3-ζ) into patients with high-risk B-lymphoid malignancies undergoing autologous HSCT. The T cells are genetically modified by nonviral gene transfer of the Sleeping Beauty system and CAR(+) T cells selectively propagated in a CAR-dependent manner on designer artificial antigen-presenting cells. The results of this study will lay the foundation for future protocols including CAR(+) T-cell infusions derived from allogeneic sources.

  20. Power Control of Low Frequency AC Transmission Systems Using Cycloconverters with Virtual Synchronous Generator Control

    Directory of Open Access Journals (Sweden)

    Achara Pichetjamroen

    2016-12-01

    Full Text Available This paper is focused on the application of a multi-terminal line-commutated converter-type low frequency AC transmission system (MTLF using a cycloconverter by applying a new power control scheme for multi-terminal operation. With the virtual synchronous generator (VSG control scheme, the transmitting power among the multi-terminal system can be accomplished without a communication link for frequency synchronization in each terminal. The details of the proposed control scheme are explained in order to understand the advantages of this method. The configuration of a two-phase low frequency AC transmission system (LFAC is adopted to examine with the proposed control scheme. Simulation results are provided to illustrate the proposed control scheme with respect to the LFAC system’s performance.

  1. Use of engineered bone for sinus augmentation.

    Science.gov (United States)

    Beaumont, Christian; Schmidt, Roswitha J; Tatakis, Dimitris N; Zafiropoulos, Gregory-George

    2008-03-01

    Tissue-engineered bone grafts represent an appealing alternative for maxillary sinus augmentation because they eliminate the significant drawbacks associated with extra- and intraoral bone-harvesting procedures. In the present case series, we document the outcomes of sinus augmentation surgery using tissue-engineered bone grafts. Three patients requiring bilateral sinus augmentation received tissue-engineered bone grafts combined with xenograft prior to implant placement. Implants were placed and loaded 6 and 12 months postaugmentation, respectively. Radiographs were taken and clinical examinations were performed preoperatively and at 4, 6, 12, and 18 months postaugmentation. Biopsies were obtained at 4 and 6 months postaugmentation. Standardized orthopantomograms were used to measure the posterior maxilla bone height. None of the patients experienced untoward complications during or following the therapeutic procedures. Ten implants were inserted into the augmented sinuses and loaded. Biopsies revealed a lack of inflammation or pathology; newly formed fibrous bone with osteoblastic activity and xenograft particles was evident. Compared to 4 months postaugmentation, augmented tissue was more mature at 6 months. The postoperative (18 months) bone height in augmented areas was significantly greater than the preoperative height (P bone height. Sinus augmentation using tissue-engineered bone grafts was successful in all three cases, permitting the subsequent insertion and loading of dental implants. The present cases demonstrated the feasibility of using engineered bone for sinus augmentation. Controlled clinical trials will be required to evaluate this new and evolving treatment modality.

  2. Augmented Reality Interfaces for Additive Manufacturing

    OpenAIRE

    Eiríksson, Eyþór Rúnar; Pedersen, David Bue; Frisvad, Jeppe Revall; Skovmand, Linda; Heun, Valentin; Maes, Pattie; Aanæs, Henrik

    2017-01-01

    This paper explores potential use cases for using augmented reality (AR) as a tool to operate industrial machines. As a baseline we use an additive manufacturing system, more commonly known as a 3D printer. We implement novel augmented interfaces and controls using readily available open source frameworks and low cost hardware. Our results show that the technology enables richer and more intuitive printer control and performance monitoring than currently available on the market. Therefore, th...

  3. Contamination Control Considerations for the Next Generation Space Telescope (NGST)

    Science.gov (United States)

    Wooldridge, Eve M.

    1998-01-01

    The NASA Space Science Program, in its ongoing mission to study the universe, has begun planning for a telescope that will carry on the Hubble Space Telescope's exploration. This telescope, the 'Next Generation Space Telescope' (NGST), will be 6-8 meters in diameter, will be radiatively cooled to 30-60 Kelvin in order to enable extremely deep exposures at near infrared wavelengths, and will operate for a lifetime of 5-10 years. The requirement will be to measure wavelengths from 1-5 microns, with a goal to measure wavelengths from 0.6-30 microns. As such, NGST will present a new contamination control challenge. The Goddard Space Flight Center (GSFC) performed one of three preliminary feasibility studies for the NGST, presenting a telescope with an 8 meter, deployable primary mirror and a deployable secondary mirror. The telescope would be radiatively cooled, with the optical telescope assembly (OTA) and the science instrument module (SIM) isolated from the warmer spacecraft support module (SSM). The OTA and the SIM would also be shielded from sunlight with an enormous, inflatable sun-shield. The GSFC telescope was designed for launch on an Atlas HAS, which would require launching the telescope in a stowed configuration, with the SSM, antennae, sun-shield, primary mirror 'petals', and secondary mirror deployed once on-orbit. The launch configuration and deployment scenario of an exposed telescope measuring near infrared and cooled to 30-60 K are the factors presenting contamination hazards to the NGST mission. Preliminary science requirements established are: less than 20% reflectance decrease on optical surfaces over the wavelength range, and less than 0.3% obscuration of optical surfaces. In order to meet these requirements, NGST must be built and launched with careful attention to contamination control. Initial contamination control design options include strict selecting of materials and baking out of hardware down to the component level, minimizing or

  4. Second Generation Advanced Reburning for High Efficiency NOx Control

    Energy Technology Data Exchange (ETDEWEB)

    Vladimir M. Zamansky; Peter M. Maly; Vitali V. Lissianski; Mark S. Sheldon; David Moyeda; Roy Payne

    2001-06-30

    This project develops a family of novel Second Generation Advanced Reburning (SGAR) NO{sub x} control technologies, which can achieve 95% NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction (SCR). The conventional Advanced Reburning (AR) process integrates basic reburning and N-agent injection. The SGAR systems include six AR variants: (1) AR-Lean--injection of the N-agent and promoter along with overfire air; (2) AR-Rich--injection of N-agent and promoter into the reburning zone; (3) Multiple Injection Advanced Reburning (MIAR)--injection of N-agents and promoters both into the reburning zone and with overfire air; (4) AR-Lean + Promoted SNCR--injection of N-agents and promoters with overfire air and into the temperature zone at which Selective Non-Catalytic Reduction (SNCR) is effective; (5) AR-Rich + Promoted SNCR--injection of N-agents and promoters into the reburning zone and into the SNCR zone; and (6) Promoted Reburning + Promoted SNCR--basic or promoted reburning followed by basic or promoted SNCR process. The project was conducted in two phases over a five-year period. The work included a combination of analytical and experimental studies to confirm the process mechanisms, identify optimum process configurations, and develop a design methodology for full-scale applications. Phase I was conducted from October, 1995 to September, 1997 and included both analytical studies and tests in bench and pilot-scale test rigs. Phase I moved AR technology to Maturity Level III-Major Subsystems. Phase II is conducted over a 45 month period (October, 1997-June, 2001). Phase II included evaluation of alternative promoters, development of alternative reburning fuel and N-Agent jet mixing systems, and scale up. The goal of Phase II was to move the technology to Maturity Level I-Subscale Integrated System. Tests in combustion facility ranging in firing rate from 0.1 x 10{sup 6} to 10 x 10{sup 6} Btu/hr demonstrated the

  5. Confronting an Augmented Reality

    Science.gov (United States)

    Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

  6. Augmented reality building operations tool

    Science.gov (United States)

    Brackney, Larry J.

    2014-09-09

    A method (700) for providing an augmented reality operations tool to a mobile client (642) positioned in a building (604). The method (700) includes, with a server (660), receiving (720) from the client (642) an augmented reality request for building system equipment (612) managed by an energy management system (EMS) (620). The method (700) includes transmitting (740) a data request for the equipment (612) to the EMS (620) and receiving (750) building management data (634) for the equipment (612). The method (700) includes generating (760) an overlay (656) with an object created based on the building management data (634), which may be sensor data, diagnostic procedures, or the like. The overlay (656) is configured for concurrent display on a display screen (652) of the client (642) with a real-time image of the building equipment (612). The method (700) includes transmitting (770) the overlay (656) to the client (642).

  7. FRONTOTEMPORAL AND DOPAMINERGIC CONTROL OF IDEA GENERATION AND CREATIVE DRIVE

    OpenAIRE

    Flaherty, Alice W.

    2005-01-01

    This paper presents a three-factor anatomical model of human idea generation and creative drive, focusing on interactions between the temporal lobes, frontal lobes, and limbic system. Evidence is drawn from functional imaging, drug studies, and lesion analysis. Temporal lobe changes, as in hypergraphia, often increase idea generation, sometimes at the expense of quality. Frontal lobe deficits may decrease idea generation, in part because of rigid judgments about an idea's worth. These phenome...

  8. Active Power and Flux Control of a Self-Excited Induction Generator for a Variable-Speed Wind Turbine Generation

    Energy Technology Data Exchange (ETDEWEB)

    Na, Woonki; Muljadi, Eduard; Leighty, Bill; Kim, Jonghoon

    2017-05-11

    A Self-Excited Induction Generation (SEIG) for a variable speed wind turbine generation(VS-WG) is normally considered to be a good candidate for implementation in stand-alone applications such as battery charging, hydrogenation, water pumping, water purification, water desalination, and etc. In this study, we have examined a study on active power and flux control strategies for a SEIG for a variable speed wind turbine generation. The control analysis for the proposed system is carried out by using PSCAD software. In the process, we can optimize the control design of the system, thereby enhancing and expediting the control design procedure for this application. With this study, this control design for a SEIG for VS-WG can become the industry standard for analysis and development in terms of SEIG.

  9. Efficacy of N-Acetylcysteine Augmentation on Obsessive Compulsive Disorder: A Multicenter Randomized Double Blind Placebo Controlled Clinical Trial

    Directory of Open Access Journals (Sweden)

    Ahmad Ghanizadeh

    2017-04-01

    Full Text Available Objective: Glutamate is considered a target for treating obsessive-compulsive disorder (OCD. The efficacy and safety of the nutritional supplement of N-Acetylcysteine (NAC as an adjuvant to serotonin reuptake inhibitor (SSRI for treating children and adolescents with OCD has never been examined.Methods: This was a 10-week randomized double-blind placebo-controlled clinical trial with 34 OCD outpatients. The patients received citalopram plus NAC or placebo. Yale-Brown Obsessive-Compulsive Scale (YBOCS and Pediatric Quality of Life Inventory (PedsQL™ were used. Adverse effects were monitored.Results: YBOCS score was not different between the two groups at baseline, but the score was different between the two groups at the end of this trial (P<0.02. The YBOCS score of NAC group significantly decreased from 21.0(8.2 to 11.3(5.7 during this study. However, no statistically significant decrease of YBOCS was found in the placebo group. The Cohen’s d effect size was 0.83.The mean change of score of resistance/control to obsessions in the NAC and placebo groups was 1.8(2.3 and 0.8(2.1, respectively (P = 0.2. However, the mean score of change for resistance/control to compulsion in the NAC and placebo groups was 2.3(1.8 and 0.9(2.3, respectively. Cohen’s d effect size was 0.42.The score of three domains of quality of life significantly decreased in N-Acetylcysteine group during this trial. However, no statistically significant decrease was detected in the placebo group. No serious adverse effect was found in the two groups.Conclusion: This trial suggests that NAC adds to the effect of citalopram in improving resistance/control to compulsions in OCD children and adolescents. In addition, it is well tolerated.

  10. Current Control Method for Distributed Generation Power Generation Plants under Grid Fault Conditions

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Luna, Alvaro; Hermoso, Juan Ramon

    2011-01-01

    The operation of distributed power generation systems under grid fault conditions is a key issue for the massive integration of renewable energy systems. Several studies have been conducted to improve the response of such distributed generation systems under voltage dips. In spite of being less...

  11. Generating Control Commands From Gestures Sensed by EMG

    Science.gov (United States)

    Wheeler, Kevin R.; Jorgensen, Charles

    2006-01-01

    An effort is under way to develop noninvasive neuro-electric interfaces through which human operators could control systems as diverse as simple mechanical devices, computers, aircraft, and even spacecraft. The basic idea is to use electrodes on the surface of the skin to acquire electromyographic (EMG) signals associated with gestures, digitize and process the EMG signals to recognize the gestures, and generate digital commands to perform the actions signified by the gestures. In an experimental prototype of such an interface, the EMG signals associated with hand gestures are acquired by use of several pairs of electrodes mounted in sleeves on a subject s forearm (see figure). The EMG signals are sampled and digitized. The resulting time-series data are fed as input to pattern-recognition software that has been trained to distinguish gestures from a given gesture set. The software implements, among other things, hidden Markov models, which are used to recognize the gestures as they are being performed in real time. Thus far, two experiments have been performed on the prototype interface to demonstrate feasibility: an experiment in synthesizing the output of a joystick and an experiment in synthesizing the output of a computer or typewriter keyboard. In the joystick experiment, the EMG signals were processed into joystick commands for a realistic flight simulator for an airplane. The acting pilot reached out into the air, grabbed an imaginary joystick, and pretended to manipulate the joystick to achieve left and right banks and up and down pitches of the simulated airplane. In the keyboard experiment, the subject pretended to type on a numerical keypad, and the EMG signals were processed into keystrokes. The results of the experiments demonstrate the basic feasibility of this method while indicating the need for further research to reduce the incidence of errors (including confusion among gestures). Topics that must be addressed include the numbers and arrangements

  12. Electric Generators and their Control for Large Wind Turbines

    DEFF Research Database (Denmark)

    Boldea, Ion; Tutelea, Lucian; Rallabandi, Vandana

    2017-01-01

    The electric generator and its power electronics interface for wind turbines (WTs) have evolved rapidly toward higher reliability and reduced cost of energy in the last 40 years. This chapter describes the up-to-date electric generators existing in the wind power industry, namely, the doubly fed...

  13. a computer controlled pulse generator for an st radar system

    African Journals Online (AJOL)

    circuit in an ST radar system are provided by the radar pulse generator. The pulse generator also provides the .... A simplified circuit diagram of the hardware is shown in Fig. 5. When the CL line is set to zer0, the: pulser is .... Finally, the present pulser has been found to introduce less internal interference noise, particularily.

  14. Grid Monitoring and Advanced Control of Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile

    The movement towards a clean technology for energy production and the constraints in reducing the CO2 emissions are some factors facilitating the growth of distributed power generation systems based on renewable energy resources. Consequently, large penetration of distributed generators has been ...

  15. Controlled generation and use of CO in flow

    DEFF Research Database (Denmark)

    Hansen, Steffen V. F.; Wilson, Zoe E.; Ulven, Trond

    2016-01-01

    A method for the generation and use of carbon monoxide in flow chemistry has been developed. By using a tube-in-tube reactor, oxalyl chloride can be conveniently and safely hydrolyzed using a NaOH solution to generate CO in the outer stream, which then passes through AF-2400 semi-permeable inner...

  16. Investigation of excitation control for wind-turbine generator stability

    Science.gov (United States)

    Gebben, V. D.

    1977-01-01

    High speed horizontal axis wind turbine generators with blades on the downwind side of the support tower require special design considerations to handle disturbances introduced by the flow wake behind the tower. Experiments and analytical analyses were made to determine benefits that might be obtained by using the generator exciter to provide system damping for reducing power fluctuations.

  17. Power generation and control of a self excited squirrel cage ...

    African Journals Online (AJOL)

    Nigerian Journal of Technology ... The wind turbine is to be tied mechanically to the rotor of a squirrel cage induction which is fed with grid powerthat the generator supplies. ... Keywords: Wind Power systems, Self-excited squirrel cage induction generator, squirrel cage induction motor, backto- back converter, simulation ...

  18. Trauma management therapy with virtual-reality augmented exposure therapy for combat-related PTSD: A randomized controlled trial.

    Science.gov (United States)

    Beidel, Deborah C; Frueh, B Christopher; Neer, Sandra M; Bowers, Clint A; Trachik, Benjamin; Uhde, Thomas W; Grubaugh, Anouk

    2017-08-23

    Virtual reality exposure therapy (VRET) realistically incorporates traumatic cues into exposure therapy and holds promise in the treatment of combat-related posttraumatic stress disorder (PTSD). In a randomized controlled trial of 92 Iraq and Afghanistan veterans and active duty military personnel with combat-related PTSD, we compared the efficacy of Trauma Management Therapy (TMT; VRET plus a group treatment for anger, depression, and social isolation) to VRET plus a psychoeducation control condition. Efficacy was evaluated at mid- and post-treatment, and at 3- and 6-month follow-up. Consistent with our hypothesis, VRET resulted in significant decreases on the Clinician Administered PTSD Scale and the PTSD Checklist-Military version for both groups. Also consistent with our hypothesis, significant decreases in social isolation occurred only for those participants who received the TMT group component. There were significant decreases for depression and anger for both groups, although these occurred after VRET and before group treatment. All treatment gains were maintained six-months later. Although not part of the original hypotheses, sleep was not improved by either intervention and remained problematic. The results support the use of VRET as an efficacious treatment for combat-related PTSD, but suggest that VRET alone does not result in optimal treatment outcomes across domains associated with PTSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The Effect of Continuous and Discretized Presentations of Concurrent Augmented Visual Biofeedback on Postural Control in Quiet Stance.

    Directory of Open Access Journals (Sweden)

    Carmen D'Anna

    Full Text Available The purpose of this study was to evaluate the effect of a continuous and a discretized Visual Biofeedback (VBF on balance performance in upright stance. The coordinates of the Centre of Pressure (CoP, extracted from a force plate, were processed in real-time to implement the two VBFs, administered to two groups of 12 healthy participants. In the first group, a representation of the CoP was continuously shown, while in the second group, the discretized VBF was provided at an irregular frequency (that depended on the subject's performance by displaying one out of a set of five different emoticons, each corresponding to a specific area covered by the current position of the CoP. In the first case, participants were asked to maintain a white spot within a given square area, whereas in the second case they were asked to keep the smiling emoticon on. Trials with no VBF were administered as control. The effect of the two VBFs on balance was studied through classical postural parameters and a subset of stabilogram diffusion coefficients. To quantify the amount of time spent in stable conditions, the percentage of time during which the CoP was inside the stability area was calculated. Both VBFs improved balance maintainance as compared to the absence of any VBF. As compared to the continuous VBF, in the discretized VBF a significant decrease of sway path, diffusion and Hurst coefficients was found. These results seem to indicate that a discretized VBF favours a more natural postural behaviour by promoting a natural intermittent postural control strategy.

  20. Hierarchical Coordinated Control of Distributed Generators and Active Power Filters to Enhance Power Quality of Microgrids

    DEFF Research Database (Denmark)

    Savaghebi, Mehdi; Hashempour, Mohammad M.; Guerrero, Josep M.

    2014-01-01

    This paper addresses the coordinated control of distributed generators (DGs) inverters and active power filters (APFs) to compensate voltage harmonics in microgrids. For this, a hierarchical control system is proposed to mitigate voltage harmonic distortion. The hierarchical control structure...... includes two control levels: primary control and secondary control. Primary control consists of power controllers, selective virtual impedance loops and proportional-resonant (PR) voltage/current controllers. Secondary control manages the compensation of voltage harmonic distortion of sensitive load bus...

  1. The effect of mirtazapine augmentation of clozapine in the treatment of negative symptoms of schizophrenia: a double-blind, placebo-controlled study.

    Science.gov (United States)

    Zoccali, Rocco; Muscatello, Maria Rosaria; Cedro, Clemente; Neri, Pietro; La Torre, Diletta; Spina, Edoardo; Di Rosa, Antonio Enrico; Meduri, Mario

    2004-03-01

    The development of therapeutic strategies to effectively treat negative symptoms remains one of the primary goals in the treatment of schizophrenia. Mirtazapine is the first of a new class of dual action compounds, the noradrenergic and specific serotonergic antidepressants (NaSSa), whose activity is related to the enhancement of noradrenergic and serotonergic transmission by a presynaptic alpha2 antagonism and postsynaptic 5-HT2 and 5-HT3 antagonism, respectively. This study was a 8-week double-blind, randomized, placebo-controlled trial of 30 mg adjunctive mirtazapine to clozapine therapy in 24 patients with DSM-IV schizophrenia. The main finding at the end of the trial was a significant reduction on the Scale for the Assessment of Negative Symptoms (SANS) total scores in the mirtazapine group compared to placebo (P<0.01) with a significant improvement on the SANS subscales avolition/apathy and anhedonia/asociality. The Brief Psychiatric Rating Scale total score at week 8 showed superiority of mirtazapine over placebo. These findings suggest a potential role for mirtazapine as an augmentation strategy in the treatment of negative symptoms of schizophrenia.

  2. Increasing the capacity of distributed generation in electricity networks by intelligent generator control

    OpenAIRE

    Aristides E. Kiprakis

    2005-01-01

    The rise of environmental awareness as well as the unstable global fossil fuel market has brought about government initiatives to increase electricity generation from renewable energy sources. These resources tend to be geographically and electrically remote from load centres. Consequently many Distributed Generators (DGs) are expected to be connected to the existing Distribution Networks (DNs), which have high impedance and low X/R ratios. Intermittence and unpredictability of the vario...

  3. Application of distributed control system to power generator controlling system; Hatsudenki seigyokei eno bunsanseigyo hoshiki eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Morioka, Y. [Kansai Electric Power Co. Inc., Osaka (Japan)

    1999-05-10

    The method to apply a distributed control system to power generator controlling systems has been studied, where the distributed control is based on the H infinitive control for a multi-machine system as the model for the whole system to be controlled. The digital simulation was also conducted to verify the system. In the distributed control system, one generator is taken as one sub-system and the portions representing its interactions with other generators are taken as disturbances to the generator in question, because the H infinitive control is used. It is designed to stabilize the system from the disturbances by applying the disturbance-preventing control of the H infinitive control. The digital simulation was conducted for a 3-machine loop system and system with 5 machines connected in series. It is confirmed that the proposed method shows better controllability than the conventional one, securing robustness to changed system conditions and synergistic effects when applied to plural machines. (NEDO)

  4. Dual γ rhythm generators control interlaminar synchrony in auditory cortex

    National Research Council Canada - National Science Library

    Ainsworth, Matthew; Lee, Shane; Cunningham, Mark O; Roopun, Anita K; Traub, Roger D; Kopell, Nancy J; Whittington, Miles A

    2011-01-01

    .... Here we show that, for inhibition-based gamma rhythms in vitro in rat neocortical slices, mechanistically distinct local circuit generators exist in different laminae of rat primary auditory cortex...

  5. Facilitation of fear extinction in phobic participants with a novel cognitive enhancer: a randomized placebo controlled trial of yohimbine augmentation.

    Science.gov (United States)

    Powers, Mark B; Smits, Jasper A J; Otto, Michael W; Sanders, Carlijn; Emmelkamp, Paul M G

    2009-04-01

    Preliminary animal research suggests that yohimbine hydrochloride, a selective competitive alpha2-adrenergic receptor antagonist, accelerates fear extinction and converts ineffective extinction regimens (long intertrial intervals) to effective ones. This randomized placebo controlled study examined the potential exposure enhancing effect of yohimbine hydrochloride in claustrophobic humans. Participants (71% undergraduate students and 29% community volunteers) displaying marked claustrophobic fear (n=24) were treated with 2 1-h in vivo exposure sessions. Participants were randomly allocated to take 10.8mg yohimbine hydrochloride (n=12) or placebo (n=12) prior to each exposure session. Outcome measures included peak fear during a behavioral avoidance task, the Claustrophobia Questionnaire, and the Claustrophobic Concerns Questionnaire. Results showed that both conditions improved significantly at post-treatment with no significant difference between groups. Consistent with prediction the group that took yohimbine hydrochloride prior to exposure sessions showed significantly greater improvement in peak fear at the one-week follow-up behavioral assessment (d=1.68). This was also true across other outcome measures with large to very large effect sizes. These data provide initial support for exposure enhancing effect of single-dose yohimbine hydrochloride in a clinical application.

  6. Augmented reality: a review.

    Science.gov (United States)

    Berryman, Donna R

    2012-01-01

    Augmented reality is a technology that overlays digital information on objects or places in the real world for the purpose of enhancing the user experience. It is not virtual reality, that is, the technology that creates a totally digital or computer created environment. Augmented reality, with its ability to combine reality and digital information, is being studied and implemented in medicine, marketing, museums, fashion, and numerous other areas. This article presents an overview of augmented reality, discussing what it is, how it works, its current implementations, and its potential impact on libraries.

  7. Control mechanisms in the third-generation planning. Case study: Control to realize sustainable cities

    Science.gov (United States)

    Wicaksono, A. D.

    2017-06-01

    Since the last few years, Indonesia has experienced important events that bring significant changes to the social, political and economic life. The changes directly or indirectly impact the field of planning. With the challenging condition which grows fast and is more complex ahead, and the greater demands on the role of planning, it is required that planning should have higher quality. This paper seeks to answer some questions as follows: (i) How are changes in paradigm and also the development of planning model for the current transition era?, (ii) What is the best way to improve the quality of planning control on the last generation planning model to realize sustainable city?. Analysis steps that will be used to achieve the paper objectives are: (i) Review of planning and sustainable cities theory, (ii) Pattern recognition, (iii) Identifying control mechanisms and sustainable urban forms, (iv) conceptualization. Based on discussion about sustainable cities and control mechanism, some conclusions can be generated as follows: (i) The third generation planning model is based on the theory of expanded system, emphasizing on the constraint of capacity and the ability of planners within the context of larger environment, (ii) There are various theoretical studies that recommend prescriptive model or solution for sustainable urban form and structure. The concepts of Sustainable Cities can be grouped in Neotraditional Development, Urban Containment, Compact City and The Eco-City. The four models above have criteria, namely (i) high density; (ii) a high level of diversity; (iii) mixed land use; (iv) compactness; (5) sustainable transport; (6) passive solar design; (7) Greening Ecological Design. The three main activities in control mechanisms are: Monitoring and Recommendation; a comparative review of the facts (conditions that exist or are developing) with the purpose (expected conditions, set out in urban planning) and recommendations; Evaluation, a review on the

  8. The frequency-independent control method for distributed generation systems

    DEFF Research Database (Denmark)

    Naderi, Siamak; Pouresmaeil, Edris; Gao, Wenzhong David

    2012-01-01

    are controlled in the synchronously rotating orthogonal . dq reference frame. The transformed variables are used in control of the voltage source inverter that connects DG to distribution network. Due to importance of distributed resources in modern power systems, development of new, practical, cost......-effective and simple control strategies is obligatory. The new control method of this paper does not need a Phase Locked Loop (PLL) in control circuit and has fast dynamic response in providing active and reactive power to nonlinear load. From extensive simulation results, high performance of this control strategy...

  9. Texting Motivational Interviewing: A Randomized Controlled Trial of Motivational Interviewing Text Messages Designed to Augment Childhood Obesity Treatment.

    Science.gov (United States)

    Armstrong, Sarah; Mendelsohn, Alan; Bennett, Gary; Taveras, Elsie M; Kimberg, Amanda; Kemper, Alex R

    2018-01-01

    Text messages improve health outcomes for adults engaged in weight management. Little is known about whether text messaging parents of children enrolled in obesity treatment will improve child health. We conducted a 2-group randomized controlled study among 101 children aged 5-12 and their parent/guardian enrolling in tertiary-care obesity treatment. Participants were randomized to standard care or standard care plus daily motivational interviewing-based text messages. The primary outcome was change in child BMI at 3 months. Secondary outcomes included feasibility, health behaviors, attrition, motivation, and parent BMI. We enrolled 101 parent-child dyads and retained 81% to 3-month follow-up. Child participants had a mean age of 9.9 years, and baseline BMI of 30.5 kg/m2. Half (48%) of participants were Black, and 64% of parent participants had a high school equivalent education or less. Ninety-nine percent of parents owned a mobile device with unlimited text messaging. Parents responded to 80% of texts, and 95% felt the texts "always" or "almost always" helped them make a good health decision. We observed no between-group difference in child zBMI from baseline to 3 months (0.0 vs. 0.2, p = 0.2). Intervention participants had significantly better adherence to clinic visits (3.3 visits vs. 2.1 visits/3 months, p text messages did not significantly change child BMI. However, texting significantly reduced attrition for treatment visits. Nearly all parents in this racially diverse, low-income sample engaged in daily text messaging, making this a feasible approach.

  10. Ziprasidone Augmentation of Escitalopram for Major Depressive Disorder: Efficacy Results From a Randomized, Double-Blind, Placebo-Controlled Study.

    Science.gov (United States)

    Papakostas, George I; Fava, Maurizio; Baer, Lee; Swee, Michaela B; Jaeger, Adrienne; Bobo, William V; Shelton, Richard C

    2015-12-01

    The authors sought to test the efficacy of adjunctive ziprasidone in adults with nonpsychotic unipolar major depression experiencing persistent symptoms after 8 weeks of open-label treatment with escitalopram. This was an 8-week, randomized, double-blind, parallel-group, placebo-controlled trial conducted at three academic medical centers. Participants were 139 outpatients with persistent symptoms of major depression after an 8-week open-label trial of escitalopram (phase 1), randomly assigned in a 1:1 ratio to receive adjunctive ziprasidone (escitalopram plus ziprasidone, N=71) or adjunctive placebo (escitalopram plus placebo, N=68), with 8 weekly follow-up assessments. The primary outcome measure was clinical response, defined as a reduction of at least 50% in score on the 17-item Hamilton Depression Rating Scale (HAM-D). The Hamilton Anxiety Rating scale (HAM-A) and Visual Analog Scale for Pain were defined a priori as key secondary outcome measures. Rates of clinical response (35.2% compared with 20.5%) and mean improvement in HAM-D total scores (-6.4 [SD=6.4] compared with -3.3 [SD=6.2]) were significantly greater for the escitalopram plus ziprasidone group. Several secondary measures of antidepressant efficacy also favored adjunctive ziprasidone. The escitalopram plus ziprasidone group also showed significantly greater improvement on HAM-A score but not on Visual Analog Scale for Pain score. Ten (14%) patients in the escitalopram plus ziprasidone group discontinued treatment because of intolerance, compared with none in the escitalopram plus placebo group. Ziprasidone as an adjunct to escitalopram demonstrated antidepressant efficacy in adult patients with major depressive disorder experiencing persistent symptoms after 8 weeks of open-label treatment with escitalopram.

  11. Metformin to Augment Strength Training Effective Response in Seniors (MASTERS): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Long, Doug E; Peck, Bailey D; Martz, Jenny L; Tuggle, S Craig; Bush, Heather M; McGwin, Gerald; Kern, Philip A; Bamman, Marcas M; Peterson, Charlotte A

    2017-04-26

    Muscle mass and strength are strong determinants of a person's quality of life and functional independence with advancing age. While resistance training is the most effective intervention to combat age-associated muscle atrophy (sarcopenia), the ability of older adults to increase muscle mass and strength in response to training is blunted and highly variable. Thus, finding novel ways to complement resistance training to improve muscle response and ultimately quality of life among older individuals is critical. The purpose of this study is to determine whether a commonly prescribed medication called metformin can be repurposed to improve the response to resistance exercise training by altering the muscle tissue inflammatory environment. Individuals aged 65 and older are participating in a two-site, randomized, double-blind, placebo-controlled trial testing the effects of metformin or placebo on muscle size, strength, and physical function when combined with a progressive resistance training program. Participants consume 1700 mg of metformin per day or placebo for 2 weeks before engaging in a 14-week progressive resistance training regimen, with continued metformin or placebo. Participants are then monitored post-training to determine if the group taking metformin derived greater overall benefit from training in terms of muscle mass and strength gains than those on placebo. Muscle biopsies are taken from the vastus lateralis at three time points to assess individual cellular and molecular adaptations to resistance training and also changes in response to metformin. The response of aged muscles to a resistance training program does not always result in a positive outcome; some individuals even experience a loss in muscle mass following resistance training. Thus, adjuvant therapies, including pharmacological ones, are required to optimize response to training in those who do not respond and may be at increased risk of frailty. This is the first known metformin

  12. Exhaust gas bypass valve control for thermoelectric generator

    Science.gov (United States)

    Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter Jacobus; Anderson, Todd Alan

    2012-09-04

    A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

  13. A digital control system for high level acoustic noise generation

    Science.gov (United States)

    Lee, John P.; Bosco, Jerry H.

    1986-01-01

    As part of the modernization of the Acoustic Test Facility at Lockheed Missiles and Space Company, Sunnyvale, a digital acoustic control system was designed and built. The requirements imposed by Lockheed on the control system and the degree to which those requirements were met are discussed. Acceptance test results as well as some of the features of the digital control system not found in traditional manual control systems are discussed.

  14. Human-in-the-loop evaluation of RMS Active Damping Augmentation

    Science.gov (United States)

    Demeo, Martha E.; Gilbert, Michael G.; Scott, Michael A.; Lepanto, Janet A.; Bains, Elizabeth M.; Jensen, Mary C.

    1993-01-01

    Active Damping Augmentation is the insertion of Controls-Structures Integration Technology to benefit the on-orbit performance of the Space Shuttle Remote Manipulator System. The goal is to reduce the vibration decay time of the Remote Manipulator System following normal payload maneuvers and operations. Simulation of Active Damping Augmentation was conducted in the realtime human-in-the-loop Systems Engineering Simulator at the NASA Johnson Space Center. The objective of this study was to obtain a qualitative measure of operational performance improvement from astronaut operators and to obtain supporting quantitative performance data. Sensing of vibratory motions was simulated using a three-axis accelerometer mounted at the end of the lower boom of the Remote Manipulator System. The sensed motions were used in a feedback control law to generate commands to the joint servo mechanisms which reduced the unwanted oscillations. Active damping of the Remote Manipulator System with an attached 3990 lb. payload was successfully demonstrated. Six astronaut operators examined the performance of an Active Damping Augmentation control law following single-joint and coordinated six-joint translational and rotational maneuvers. Active Damping Augmentation disturbance rejection of Orbiter thruster firings was also evaluated. Significant reductions in the dynamic response of the 3990 lb. payload were observed. Astronaut operators recommended investigation of Active Damping Augmentation benefits to heavier payloads where oscillations are a bigger problem (e.g. Space Station Freedom assembly operators).

  15. Augmented Reality for Maintenance and Repair (ARMAR)

    Science.gov (United States)

    2007-08-01

    of tracking and display technologies, and computer graphics hardware and software, and has a long tradition of research in AR theory and practice ... practice , a user can learn to negotiate the nearby augmented controls while keeping their eyes focused on the repair area. Second, because the...2005, pp. 47-54. [8] A. C. Boud, D. J. Haniff, C. Baber , and S. J. Steiner, "Virtual Reality and Augmented Reality as a Training Tool for

  16. Next-Generation Maneuvering System with Control-Moment Gyroscopes for Extravehicular Activities Near Low-Gravity Objects

    Science.gov (United States)

    Carpenter, Michele; Jackson, Kimberly; Cohanim, Babak; Duda, Kevin R.; Rize, Jared; Dopart, Celena; Hoffman, Jeffrey; Curiel, Pedro; Studak, Joseph; Ponica, Dina; hide

    2013-01-01

    Looking ahead to the human exploration of Mars, NASA is planning for exploration of near-Earth asteroids and the Martian moons. Performing tasks near the surface of such low-gravity objects will likely require the use of an updated version of the Manned Maneuvering Unit (MMU) since the surface gravity is not high enough to allow astronauts to walk, or have sufficient resistance to counter reaction forces and torques during movements. The extravehicular activity (EVA) Jetpack device currently under development is based on the Simplified Aid for EVA Rescue (SAFER) unit and has maneuvering capabilities to assist EVA astronauts with their tasks. This maneuvering unit has gas thrusters for attitude control and translation. When EVA astronauts are performing tasks that require ne motor control such as sample collection and equipment placement, the current control system will re thrusters to compensate for the resulting changes in center-of-mass location and moments of inertia, adversely affecting task performance. The proposed design of a next-generation maneuvering and stability system incorporates control concepts optimized to support astronaut tasks and adds control-moment gyroscopes (CMGs) to the current Jetpack system. This design aims to reduce fuel consumption, as well as improve task performance for astronauts by providing a sti er work platform. The high-level control architecture for an EVA maneuvering system using both thrusters and CMGs considers an initial assessment of tasks to be performed by an astronaut and an evaluation of the corresponding human-system dynamics. For a scenario in which the astronaut orbits an asteroid, simulation results from the current EVA maneuvering system are compared to those from a simulation of the same system augmented with CMGs, demonstrating that the forces and torques on an astronaut can be significantly reduced with the new control system actuation while conserving onboard fuel.

  17. Control and stabilization of the DOE/NASA Mod-1 two megawatt wind turbine generator

    Science.gov (United States)

    Barton, R. S.; Bowler, C. E. J.; Piwko, R. J.

    1979-01-01

    This paper describes the controls design, performance simulation process and specialized dynamic considerations for the DOE/NASA Mod 1 wind turbine generator (WTG). It shows controls, structural and utility interface considerations of the wind turbine generator and shows how a wind turbine generator can be integrated with a synchronous power system. Differences with respect to fossil or hydro generation and their implications are vital to long-term WTG reliability and availability and acceptance by utilities and consumers. The paper describes the control performance requirements to provide stable pitch and excitation control with drivetrain torsional dynamics, and the control of power swing stability and utility feeder voltage due to wind gusts.

  18. Augmenting the access grid using augmented reality

    Science.gov (United States)

    Li, Ying

    2012-01-01

    The Access Grid (AG) targets an advanced collaboration environment, with which multi-party group of people from remote sites can collaborate over high-performance networks. However, current AG still employs VIC (Video Conferencing Tool) to offer only pure video for remote communication, while most AG users expect to collaboratively refer and manipulate the 3D geometric models of grid services' results in live videos of AG session. Augmented Reality (AR) technique can overcome the deficiencies with its characteristics of combining virtual and real, real-time interaction and 3D registration, so it is necessary for AG to utilize AR to better assist the advanced collaboration environment. This paper introduces an effort to augment the AG by adding support for AR capability, which is encapsulated in the node service infrastructure, named as Augmented Reality Service (ARS). The ARS can merge the 3D geometric models of grid services' results and real video scene of AG into one AR environment, and provide the opportunity for distributed AG users to interactively and collaboratively participate in the AR environment with better experience.

  19. Reversible Photochemical Control of Singlet Oxygen Generation Using Diarylethene Photochromic Switches

    NARCIS (Netherlands)

    Hou, Lili; Zhang, Xiaoyan; Pijper, Thomas C.; Browne, Wesley R.; Feringa, Bernard

    2014-01-01

    Reversible noninvasive control over the generation of singlet oxygen is demonstrated in a bicomponent system comprising a diarylethene photochromic switch and a porphyrin photosensitizer by selective irradiation at distinct wavelengths. The efficient generation of singlet oxygen by the

  20. Next Generation Advanced Binder Chemistries for High Performance, Environmentally DurableThermal Control Material Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovative SBIR Phase II proposal will develop next generation products for Thermal Control Material Systems (TCMS) an adhesives based on the next generation...

  1. High-tension corona controlled ozone generator for environment protection

    Science.gov (United States)

    Vijayan, T.; Patil, Jagadish G.

    2010-02-01

    Engineering details of a high voltage driven corona-plasma ozone generator are described. The plasma diode of generator has coaxial cylindrical geometry with cathode located inside anode. Cathode is made of a large number of radial gas nozzles arranged on central tubular mast which admits oxygen gas. The sharp endings of the nozzles along with a set of corona rings create the high electric field at the cathode required for formation of dense corona plume responsible for O3 evolution. A model of coronal plasma generation and ozone production is presented. The plasma formation is strongly dependent on the electric field and temperature in side diode where a high electron density in a low temperature negative corona is suited for high ozone yields. These are established by suitable regulation of A-K gap, voltage, oxygen pressure, and cathode-nozzle population.

  2. A Randomized, Double-Blind Placebo-Controlled Trial of Oral Creatine Monohydrate Augmentation for Enhanced Response to a Selective Serotonin Reuptake Inhibitor in Women With Major Depressive Disorder

    Science.gov (United States)

    Kim, Tae-Suk; Hwang, Jaeuk; Kim, Jieun E.; Won, Wangyoun; Bae, Sujin; Renshaw, Perry F.

    2015-01-01

    Objective Antidepressants targeting monoaminergic neurotransmitter systems, despite their immediate effects at the synaptic level, usually require several weeks of administration to achieve clinical efficacy. The authors propose a strategy of adding creatine monohydrate (creatine) to a selective serotonin reuptake inhibitor (SSRI) in the treatment of patients with major depressive disorder. Such augmentation may lead to a more rapid onset of antidepressant effects and a greater treatment response, potentially by restoring brain bioenergetics at the cellular level. Method Fifty-two women with major depressive disorder were enrolled in an 8-week double-blind placebo-controlled clinical trial and randomly assigned to receive escitalopram in addition to either creatine (5 g/day, N=25) or placebo (N=27). Efficacy was primarily assessed by changes in the Hamilton Depression Rating Scale (HAM-D) score. Results In comparison to the placebo augmentation group, patients receiving creatine augmentation showed significantly greater improvements in HAM-D score, as early as week 2 of treatment. This differential improvement favoring creatine was maintained at weeks 4 and 8. There were no differences between treatment groups in the proportion of patients who discontinued treatment prematurely (creatine: N=8, 32.0%; placebo: N=5, 18.5%) or in the overall frequency of all reported adverse events (creatine: 36 events; placebo: 45 events). Conclusions The current study suggests that creatine augmentation of SSRI treatment may be a promising therapeutic approach that exhibits more rapid and efficacious responses in women with major depressive disorder. PMID:22864465

  3. Confronting an augmented reality

    Directory of Open Access Journals (Sweden)

    John Hedberg

    2012-08-01

    Full Text Available How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself? In this article, we seek to initiate a discussion that focuses on these questions, and suggest that they be used as drivers for research into effective educational applications of augmented reality. We discuss how multi-modal, sensorial augmentation of reality links to existing theories of education and learning, focusing on ideas of cognitive dissonance and the confrontation of new realities implied by exposure to new and varied perspectives. We also discuss connections with broader debates brought on by the social and cultural changes wrought by the increased digitalisation of our lives, especially the concept of the extended mind. Rather than offer a prescription for augmentation, our intention is to throw open debate and to provoke deep thinking about what interacting with and creating an augmented reality might mean for both teacher and learner.

  4. A Simple Excitation Control for an Isolated Synchronous Generator ...

    African Journals Online (AJOL)

    This paper shows a very simple method of determining the range of field voltages to be applied to an isolated synchronous generator from no-load to full load while maintaining the rated terminal voltage on the stator terminals. The d-q rotor reference frame equations were used for the calculations and it is shown that values ...

  5. Moody Music Generator: Characterising Control Parameters Using Crowdsourcing

    DEFF Research Database (Denmark)

    Scirea, Marco; Togelius, Julian; Nelson, Mark

    2015-01-01

    of generated music over the Internet, and to describe the moods with free-text labels. We find that the arousal parameter does roughly map to perceived arousal, but that the nominal “valence” parameter has strong interaction with the arousal parameter, and produces different effects in different parts...

  6. Multi-region fuzzy logic controller with local PID controllers for U-tube steam generator in nuclear power plant

    Directory of Open Access Journals (Sweden)

    Puchalski Bartosz

    2015-12-01

    Full Text Available In the paper, analysis of multi-region fuzzy logic controller with local PID controllers for steam generator of pressurized water reactor (PWR working in wide range of thermal power changes is presented. The U-tube steam generator has a nonlinear dynamics depending on thermal power transferred from coolant of the primary loop of the PWR plant. Control of water level in the steam generator conducted by a traditional PID controller which is designed for nominal power level of the nuclear reactor operates insufficiently well in wide range of operational conditions, especially at the low thermal power level. Thus the steam generator is often controlled manually by operators. Incorrect water level in the steam generator may lead to accidental shutdown of the nuclear reactor and consequently financial losses. In the paper a comparison of proposed multi region fuzzy logic controller and traditional PID controllers designed only for nominal condition is presented. The gains of the local PID controllers have been derived by solving appropriate optimization tasks with the cost function in a form of integrated squared error (ISE criterion. In both cases, a model of steam generator which is readily available in literature was used for control algorithms synthesis purposes. The proposed multi-region fuzzy logic controller and traditional PID controller were subjected to broad-based simulation tests in rapid prototyping software - Matlab/Simulink. These tests proved the advantage of multi-region fuzzy logic controller with local PID controllers over its traditional counterpart.

  7. MODELING AND STUDY OF HYDROELECTRIC GENERATING SETS OF SMALL HYDRO POWER PLANTS WITH FREQUENCY-CONTROLLED PERMANENT MAGNET SYNCHRONOUS GENERATORS

    Directory of Open Access Journals (Sweden)

    R. I. Mustafayev

    2016-01-01

    Full Text Available Currently, the hydroelectric generating sets of small HPPs with Pelton turbines employ as their generating units conventional synchronous generators with electromagnetic excitation. To deal with the torque pulsatile behaviour, they generally install a supplementary flywheel on the system shaft that levels the pulsations. The Pelton turbine power output is adjusted by the needle changing water flow in the nozzle, whose advancement modifies the nozzle area and eventually – the flow. They limit the needle full stroke time to 20–40 sec. since quick shutting the nozzle for swift water flow reduction may result in pressure surges. For quick power adjustment so-called deflectors are employed, whose task is retraction of water jets from the Pelton turbine buckets. Thus, the mechanical method of power output regulation requires agreement between the needle stroke inside the turbine nozzles and the deflector. The paper offers employing frequency-controlled synchronous machines with permanent magnets qua generating units for the hydroelectric generating sets of small HPPs with Pelton turbines. The developed computer model reveals that this provides a higher level of adjustability towards rapid-changing loads in the grid. Furthermore, this will replace the power output mechanical control involving the valuable deflector drive and the turbine nozzle needles with electrical revolution rate and power output regulation by a frequency converter located in the generator stator circuit. Via frequency start, the controllable synchronous machine ensures stable operation of the hydroelectric generating set with negligibly small amount of water (energy carrier. Finally, in complete absence of water, the frequency-relay start facilitates shifting the generator operation to the synchronous capacitor mode, which the system operating parameter fluctograms obtained through computer modeling prove. 

  8. Motion in Augmented Reality Games: An Engine for Creating Plausible Physical Interactions in Augmented Reality Games

    OpenAIRE

    Brian Mac Namee; David Beaney; Qingqing Dong

    2010-01-01

    The next generation of Augmented Reality (AR) games will require real and virtual objects to coexist in motion in immersive game environments. This will require the illusion that real and virtual objects interact physically together in a plausible way. The Motion in Augmented Reality Games (MARG) engine described in this paper has been developed to allow these kinds of game environments. The paper describes the design and implementation of the MARG engine and presents two proof-of-concept AR ...

  9. Generation and Controlled Routing of Single Plasmons on a Chip

    DEFF Research Database (Denmark)

    Kumar, Shailesh; Israelsen, Niels Møller; Huck, Alexander

    2014-01-01

    We demonstrate the excitation of single surface plasmon polaritons on a silver nanowire using a nitrogen vacancy center and the subsequent controlled coupling to a second silver nanowire. The coupling efficiency and thus the splitting ratio between the nanowires is controlled by adjusting the gap...

  10. Control of wind turbine generators connected to power systems

    Science.gov (United States)

    Hwang, H. H.; Mozeico, H. V.; Gilbert, L. J.

    1978-01-01

    A unique simulation model based on a Mode-O wind turbine is developed for simulating both speed and power control. An analytical representation for a wind turbine that employs blade pitch angle feedback control is presented, and a mathematical model is formulated. For Mode-O serving as a practical case study, results of a computer simulation of the model as applied to the problems of synchronization and dynamic stability are provided. It is shown that the speed and output of a wind turbine can be satisfactorily controlled within reasonable limits by employing the existing blade pitch control system under specified conditions. For power control, an additional excitation control is required so that the terminal voltage, output power factor, and armature current can be held within narrow limits. As a result, the variation of torque angle is limited even if speed control is not implemented simultaneously with power control. Design features of the ERDA/NASA 100-kW Mode-O wind turbine are included.

  11. On the Generating Power of Regularly Controlled Bidirectional Grammars

    NARCIS (Netherlands)

    Asveld, P.R.J.; Hogendorp, J.A.; Hogendorp, J.A.

    1991-01-01

    RCB-grammars or regularly controlled bidirectional grammars are context-free grammars of which the rules can be used in a productive and in a reductive fashion. In addition, the application of these rules is controlled by a regular language. Several modes of derivation can be distinguished for this

  12. On the Generating Power of Regularly Controlled Bidirectional Grammars

    NARCIS (Netherlands)

    Asveld, P.R.J.; Hogendorp, Jan Anne

    1989-01-01

    RCB-grammars or regularly controlled bidirectional grammars are context-free grammars of which the rules can be used in a productive and in a reductive fashion. In addition, the application of these rules is controlled by a regular language. Several modes of derivation can be distinguished for this

  13. Series pid pitch controller of large wind turbines generator

    Directory of Open Access Journals (Sweden)

    Micić Aleksandar D.

    2015-01-01

    Full Text Available For this stable process with oscillatory dynamics, characterized with small damping ratio and dominant transport delay, design of the series PID pitch controller is based on the model obtained from the open-loop process step response, filtered with the second-order Butterworth filter Fbw. Performance of the series PID pitch controller, with the filter Fbw, is analyzed by simulations of the set-point and input/output disturbance responses, including simulations with a colored noise added to the control variable. Excellent performance/robustness tradeoff is obtained, compared to the recently proposed PI pitch controllers and to the modified internal model pitch controller, developed here, which has a natural mechanism to compensate effect of dominant transport delay. [Projekat Ministarstva nauke Republike Srbije, br. III 47016

  14. Control and operation of distributed generation in distribution systems

    DEFF Research Database (Denmark)

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2011-01-01

    algorithm, which uses average rate of change off requency (Af5) and real power shift RPS), in the islanded mode. RPS will increase or decrease the power set point of the generator with increasing or decreasing system frequency, respectively. Simulation results show that the proposed method can operate......Many distribution systems nowadays have significant penetration of distributed generation (DG)and thus, islanding operation of these distribution systems is becoming a viable option for economical and technical reasons. The DG should operate optimally during both grid-connected and island...... conditions, which can be achieved with change in operating strategy. Many islanding detection techniques have been developed but little work has been done to detect grid re-connection. This paper presents strategies to operate DG in grid connected and islanded modes and a new grid re-connection detection...

  15. Multi-user Session Control in Next Generation Wireless Systems

    OpenAIRE

    Eduardo Cerqueira; Paulo Mendes; Edmundo Monteiro

    2006-01-01

    Next generation IP wireless systems are envisioned to be heterogeneous and to provide ubiquitous services to mobile users with different quality of service requirements. Furthermore, in order to attract and keep customers, mobile operators are expanding their portfolio with the inclusion of publish-subscribe services, such as real-time multimedia sessions. This paper presents a signalling application layer based on the Next Steps in Signalling (NSIS) framework that aims to provide the c...

  16. Frontotemporal and dopaminergic control of idea generation and creative drive.

    Science.gov (United States)

    Flaherty, Alice W

    2005-12-05

    This article presents a three-factor anatomical model of human idea generation and creative drive, focusing on interactions between the temporal lobes, frontal lobes, and limbic system. Evidence is drawn from functional imaging, drug studies, and lesion analysis. Temporal lobe changes, as in hypergraphia, often increase idea generation, sometimes at the expense of quality. Frontal lobe deficits may decrease idea generation, in part because of rigid judgments about an idea's worth. These phenomena are clearest in verbal creativity, and roughly parallel the pressured communication of temporal lobe epilepsy, mania, and Wernicke's aphasia-compared to the sparse speech and cognitive inflexibility of depression, Broca's aphasia, and other frontal lobe lesions. The phenomena also shape non-linguistic creativity, as in that of frontotemporal dementia. The appropriate balance between frontal and temporal activity is mediated by mutually inhibitory corticocortical interactions. Mesolimbic dopamine influences novelty seeking and creative drive. Dopamine agonists and antagonists have opposite effects on goal-directed behavior and hallucinations. Creative drive is not identical to skill-the latter depends more on neocortical association areas. However, drive correlates better with successful creative output than skill does. Traditional neuroscientific models of creativity, such as the left brain - right brain hemispheric model, emphasize skills primarily, and stress art and musical skill at the expense of language and mathematics. The three-factor model proposed here predicts findings in a broad range of normal and pathological states and can be tested in many experimental paradigms. (c) 2005 Wiley-Liss, Inc.

  17. Histological evaluation at different times after augmentation of extraction sites grafted with a magnesium-enriched hydroxyapatite: double-blinded randomized controlled trial.

    Science.gov (United States)

    Canullo, Luigi; Heinemann, Friedhelm; Gedrange, Tomasz; Biffar, Reiner; Kunert-Keil, Christiane

    2013-04-01

    To histologically analyze the early angiogenesis-osteogenesis interplay in post-extraction sockets augmented with magnesium-enriched hydroxyapatite (Mg-enriched HA). Ten post-extraction sites underwent post-extraction ridge preservation procedure. According to randomization, sites were divided into two balanced groups and bone specimens were collected 2 or 4 months after surgery. Sections were stained with hematoxylin/eosin, Masson-Goldner trichrome, and tartrate-resistant acid phosphatase (TRAP), respectively. Furthermore, indirect immunohistochemistry was performed using alkaline phosphatase, CD34 and caveolin-1 antibodies. Mean values and standard deviations were calculated for each outcome variable. Data were then compared using one-way ANOVA test. P < 0.05 was considered statistically significant. Histomorphometric analysis presented 15.0% (±3.5) regenerated bone after 2 months of healing. After 4 months, regenerated bone increased 5.1-fold up to 77.4% (± 8.6) (P < 0.001). On the contrary, vessels and capillary reduced from 645 (±33) to 255 (± 94) (caveolin-1 expression, P = 0.008). These findings were confirmed by CD34 expression (301 ± 95 and 88 (±24), respectively, at 2 and 4 months (P = 0.046). Within the limits of the present randomized controlled study, it can be concluded that Mg-enriched HA is a suitable material for socket preservation and ensures early angiogenesis and early osteogenesis. © 2012 John Wiley & Sons A/S.

  18. Randomized, Double-Blind, Placebo-Controlled Trial of N-Acetylcysteine Augmentation for Treatment-Resistant Obsessive-Compulsive Disorder.

    Science.gov (United States)

    Costa, Daniel L C; Diniz, Juliana B; Requena, Guaraci; Joaquim, Marinês A; Pittenger, Christopher; Bloch, Michael H; Miguel, Euripedes C; Shavitt, Roseli G

    2017-07-01

    To evaluate the efficacy of serotonin reuptake inhibitor (SRI) augmentation with N-acetylcysteine (NAC), a glutamate modulator and antioxidant medication, for treatment-resistant obsessive-compulsive disorder (OCD). We conducted a randomized, double-blind, placebo-controlled, 16-week trial of NAC (3,000 mg daily) in adults (aged 18-65 years) with treatment-resistant OCD, established according to DSM-IV criteria. Forty subjects were recruited at an OCD-specialized outpatient clinic at a tertiary hospital (May 2012-October 2014). The primary outcome measure was the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores. To evaluate the variables group, time, and interaction effects for Y-BOCS scores at all time points, we used nonparametric analysis of variance with repeated measures. Secondary outcomes were the severity scores for anxiety, depression, specific OCD symptom dimensions, and insight. Both groups showed a significant reduction of baseline Y-BOCS scores at week 16: the NAC group had a reduction of 4.3 points (25.6 to 21.3), compared with 3.0 points (24.8 to 21.8) for the placebo group. However, there were no significant differences between groups (P = .92). Adding NAC was superior to placebo in reducing anxiety symptoms (P = .02), but not depression severity or specific OCD symptom dimensions. In general, NAC was well tolerated, despite abdominal pain being more frequently reported in the NAC group (n [%]: NAC = 9 [60.0], placebo = 2 [13.3]; P OCD severity in treatment-resistant OCD adults. Secondary analysis suggested that NAC might have some benefit in reducing anxiety symptoms in treatment-resistant OCD patients. ClinicalTrials.gov identifier: NCT01555970.

  19. Ziprasidone Augmentation of Escitalopram for Major Depressive Disorder: Cardiac, Endocrine, Metabolic, and Motoric Effects in a Randomized, Double-Blind, Placebo-Controlled Study.

    Science.gov (United States)

    Mischoulon, David; Shelton, Richard C; Baer, Lee; Bobo, William V; Curren, Laura; Fava, Maurizio; Papakostas, George I

    2017-04-01

    To examine motoric, cardiovascular, endocrine, and metabolic effects of adjunctive ziprasidone in adults with major depressive disorder (MDD) and prior nonresponse to 8 weeks of open-label escitalopram. A multicenter, parallel, randomized, double-blind, placebo-controlled trial was conducted at 3 US academic medical centers from July 2008 to October 2013. Recruited were 139 outpatients with persistent DSM-IV MDD following an 8-week open-label trial of escitalopram. Subjects were then randomized to adjunctive ziprasidone (escitalopram + ziprasidone, n = 71) or placebo (escitalopram + placebo, n = 68) for 8 additional weeks. Cardiac and metabolic measures were obtained at each treatment visit. Barnes Akathisia Scale and Abnormal Involuntary Movement Scale (AIMS) scores were also obtained. Changes in outcome measures for each treatment group were compared by independent-samples t test. A trend toward significance (P = .06) in corrected QT interval (QTc) increase was observed for ziprasidone (mean [SD] = 8.8 [20.2] milliseconds) versus placebo (-0.02 [25.5] milliseconds). Ziprasidone-treated patients had a significantly greater increase in global akathisia scores (P = .01) and significant weight increase (mean [SD] = 3.5 [11.8] kg, or 7.7 [26.1] lb) compared to placebo (1.0 [6.4] kg, or 2.2 [14.1] lb) (P = .03). No significant changes in AIMS scores were observed for either treatment group. Adjunctive ziprasidone, added to escitalopram, led to a greater weight gain and greater but modest akathisia compared to placebo. The effect of ziprasidone on QTc showed a trend toward significance, and therefore caution should be used in the administration of ziprasidone. While ziprasidone augmentation in patients with MDD appears safe, precautions should be taken in practice, specifically regular monitoring of electrocardiogram, weight, extrapyramidal symptoms, and involuntary movements. ClinicalTrials.gov identifier: NCT00633399​​.

  20. Augmentation techniques for rotator cuff repair.

    Science.gov (United States)

    Papalia, Rocco; Franceschi, Francesco; Zampogna, Biagio; D'Adamio, Stefano; Maffulli, Nicola; Denaro, Vincenzo

    2013-01-01

    There is a high rate of recurrence of tear and failed healing after rotator cuff repair. Several strategies have proposed to augment rotator cuff repairs to improve postoperative outcome and shoulder performance. We systematically review the literature on clinical outcome following rotator cuff augmentation. We performed a comprehensive search of Medline, CINAHL, Embase and the Cochrane Central Registry of Controlled Trials, from inception of the database to 20 June 2012, using various combinations of keywords. The reference lists of the previously selected articles were then examined by hand. Only studies focusing on clinical outcomes of human patients who had undergone augmented rotator cuff repair were selected. We then evaluated the methodological quality of each article using the Coleman methodology score (CMS), a 10 criteria scoring list assessing the methodological quality of the selected studies (CMS). Thirty-two articles were included in the present review. Two were retrospective studies, and 30 were prospective. Biologic, synthetic and cellular devices were used in 24, 7 and 1 studies, respectively. The mean modified Coleman methodology score was 64.0. Heterogeneity of the clinical outcome scores makes it difficult to compare different studies. None of the augmentation devices available is without problems, and each one presents intrinsic weaknesses. There is no dramatic increase in clinical and functional assessment after augmented procedures, especially if compared with control groups. More and better scientific evidence is necessary to use augmentation of rotator cuff repairs in routine clinical practice.

  1. INTEGRAL RADIATORS FOR NEXT GENERATION THERMAL CONTROL SYSTEMS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of spacecraft thermal control systems is to maintain internal and external temperature within acceptable boundaries while minimizing impact on vehicle...

  2. Fault Tolerant and Optimal Control of Wind Turbines with Distributed High-Speed Generators

    Directory of Open Access Journals (Sweden)

    Urs Giger

    2017-01-01

    Full Text Available In this paper, the control scheme of a distributed high-speed generator system with a total amount of 12 generators and nominal generator speed of 7000 min − 1 is studied. Specifically, a fault tolerant control (FTC scheme is proposed to keep the turbine in operation in the presence of up to four simultaneous generator faults. The proposed controller structure consists of two layers: The upper layer is the baseline controller, which is separated into a partial load region with the generator torque as an actuating signal and the full-load operation region with the collective pitch angle as the other actuating signal. In addition, the lower layer is responsible for the fault diagnosis and FTC characteristics of the distributed generator drive train. The fault reconstruction and fault tolerant control strategy are tested in simulations with several actuator faults of different types.

  3. Spectral phase distribution retrieval through coherent control of harmonic generation.

    Science.gov (United States)

    Papalazarou, E; Kovacev, M; Tzallas, P; Benis, E P; Kalpouzos, C; Tsakiris, G D; Charalambidis, D

    2006-04-28

    The temporal intensity distribution of the third harmonic of a Ti:sapphire laser generated in Xe gas is fully reconstructed from its spectral phase and amplitude distributions. The spectral phases are retrieved by cross correlating the fundamental laser frequency field with that of the third harmonic, in a three laser versus one harmonic photon coupling scheme. The third harmonic spectral amplitude distribution is extracted from its field autocorrelation. The measured pulse duration is found to be in agreement with that expected from lowest order perturbation theory both for unstretched and chirped pulses.

  4. Digital control of grid connected converters for distributed power generation

    Energy Technology Data Exchange (ETDEWEB)

    Skjellnes, Tore

    2008-07-01

    Pulse width modulated converters are becoming increasingly popular as their cost decreases and power rating increases. The new trend of small scale power producers, often using renewable energy sources, has created new demands for delivery of energy to the grid. A major advantage of the pulse width modulated converter is the ability to control the output voltage at any point in the voltage period. This enables rapid response to load changes and non-linear loads. In addition it can shape the voltage in response to the output current to create an outward appearance of a source impedance. This is called a virtual impedance. This thesis presents a controller for a voltage controlled three phase pulse width modulated converter. This controller enables operation in standalone mode, in parallel with other converters in a micro grid, and in parallel with a strong main grid. A time varying virtual impedance is presented which mainly attenuates reactive currents. A method of investigating the overall impedance including the virtual impedance is presented. New net standards have been introduced, requiring the converter to operate even during severe dips in the grid voltage. Experiments are presented verifying the operation of the controller during voltage dips. (Author). 37 refs., 65 figs., 10 tabs

  5. Everything Augmented: On the Real in Augmented Reality

    Directory of Open Access Journals (Sweden)

    Hanna Schraffenberger

    2014-12-01

    Full Text Available What is augmented in Augmented Reality (AR? In this paper, we review existing opinions and show how little consensus exists on this matter. Subsequently, we approach the question from a theoretical and technology-independent perspective. We identify spatial and content-based relationships between the virtual and the real as being decisive for AR and come to the conclusion that virtual content augments that to which it relates. Subsequently, we categorize different forms of AR based on what is augmented. We distinguish between augmented environments, augmented objects, augmented humans and augmented content and consider the possibility of augmented perception. The categories are illustrated with AR (art works and conceptual differences between them are pointed out. Moreover, we discuss what the real contributes to AR and how it can shape (future AR experiences. A summary of our findings and suggestions for future research and practice, such as research into multimodal and crossmodal AR, conclude the paper.

  6. A randomized, 4-week double-blind placebo control study on the efficacy of donepezil augmentation of lithium for treatment of acute mania

    Directory of Open Access Journals (Sweden)

    Chen J

    2013-06-01

    Full Text Available Jing Chen,1 Zheng Lu,1,2 Mingyuan Zhang,1 Jie Zhang,1 Xiaodong Ni,1 Xuefeng Jiang,1 Heding Xu,1 Anisha Heeramun-Aubeeluck,2 Qiaoyan Hu,3 Hua Jin,4 John M Davis31Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China; 2Department of Psychiatry, Tongji Hospital of Tongji University, Shanghai, People’s Republic of China; 3University of Illinois at Chicago, Chicago, IL, USA; 4University of California at San Diego, San Diego, CA, USAIntroduction: A significant number of mania patients fail to respond to current pharmacotherapy, thereby there is need for novel augmentation strategies. The results of some early studies showed the effectiveness of cholinomimetics in the treatment of mania. One open case series suggested the efficacy of donepezil in the treatment of bipolar disorder. Our aim was to explore whether an oral cholinesterase inhibitor, donepezil, administered during a 4-week treatment period,would benefit patients with acute mania.Methods: We conducted a 4-week double-blind, placebo-controlled trial of donepezil as an adjunctive treatment to lithium in patients with acute mania. Eligible subjects were randomly assigned to receive donepezil or placebo in addition to lithium. Donepezil was started at 5 mg/day, and increased to 10 mg/day in the first week. Patients were rated with the Young Mania Rating Scale (YMRS and Brief Psychiatric Rating Scale (BPRS at baseline, day 1, week 1, week 2, and week 4.Results: Out of the 30 patients who were enrolled, 15 were on donepezil and 15 were on placebo. All patients completed the 4-week trial. On the first day, there was a difference of 1.97 units on the psychomotor symptoms scale of the YMRS in the donepezil group as compared to the placebo group (t = 2.39, P = 0.02. There was a difference of 0.57 units (t = 2.09, P = 0.04 in the speech item and a difference of 0.29 units in the sexual interest item (t = 2.11, P = 0.04 in the donepezil

  7. CPG-inspired workspace trajectory generation and adaptive locomotion control for quadruped robots.

    Science.gov (United States)

    Liu, Chengju; Chen, Qijun; Wang, Danwei

    2011-06-01

    This paper deals with the locomotion control of quadruped robots inspired by the biological concept of central pattern generator (CPG). A control architecture is proposed with a 3-D workspace trajectory generator and a motion engine. The workspace trajectory generator generates adaptive workspace trajectories based on CPGs, and the motion engine realizes joint motion imputes. The proposed architecture is able to generate adaptive workspace trajectories online by tuning the parameters of the CPG network to adapt to various terrains. With feedback information, a quadruped robot can walk through various terrains with adaptive joint control signals. A quadruped platform AIBO is used to validate the proposed locomotion control system. The experimental results confirm the effectiveness of the proposed control architecture. A comparison by experiments shows the superiority of the proposed method against the traditional CPG-joint-space control method.

  8. Resonance frequency analysis of implant stability in augmented and non-augmented sinus sites

    Directory of Open Access Journals (Sweden)

    Amir Moeintaghavi

    2015-12-01

    Full Text Available Background and aim:  Although there have been substantial developments in dental implant therapies, achieving good implant stability (ISQ >60 for implants inserted in augmented sinus sites appears to be challenging in comparison with non-augmented sites due to the high prevalence of bone resorption in posterior regions of maxilla. This study aimed to evaluate and compare the time required to achieve good implant stability between implants inserted in sites that had undergone a sinus augmentation procedure with implants inserted in non-augmented similar regions of maxilla. Methods: Thirty Stroman ITI Dental Implants were inserted in 14 patients (8 females and 6 males with average age of 55 ± 10 years. Fourteen implants were inserted in sinus augmented sites (open sinus elevation and Demineralized Freezed Bone Allograft  or DFDBA 6 months after healing (test group, and 16 implants were inserted into non-augmented  posterior areas of maxilla (control group. The implant stability quotient (ISQ for each implant was measured at the time of insertion (baseline, ISQ0 and at 1, 2 and 3 months later (ISQ1, ISQ2, ISQ3. Residual and augmented bone heights were also recorded. Results: The average residual bone height was 2.92 ± 0.63mm and 10.41 ± 1.46mm for the augmented bone height. The difference between ISQ values in the test and control groups was only significant at the baseline (p=0.023. No significant correlation was found between ISQ and bone height (residual and augmented, and there was no significant correlation between ISQ values and the implant diameter and length. In the test group, the differences between ISQ0 and ISQ1, ISQ1 and ISQ3 and ISQ2 and ISQ3 were all statistically significant (p=0.006, p=0.032, p=0.046. In the control group, the difference was only significant between ISQ0 and ISQ1 (p=0.002. Conclusion:  ISQ values were not statistically significant between implants inserted in natural and augmented bone six months after sinus

  9. Resonance frequency analysis of implant stability in augmented and non-augmented sinus sites

    Directory of Open Access Journals (Sweden)

    Amir Moeintaghavi

    2016-03-01

    Full Text Available Background and aim:  Although there have been substantial developments in dental implant therapies, achieving good implant stability (ISQ >60 for implants inserted in augmented sinus sites appears to be challenging in comparison with non-augmented sites due to the high prevalence of bone resorption in posterior regions of maxilla. This study aimed to evaluate and compare the time required to achieve good implant stability between implants inserted in sites that had undergone a sinus augmentation procedure with implants inserted in non-augmented similar regions of maxilla. Methods: Thirty Stroman ITI Dental Implants were inserted in 14 patients (8 females and 6 males with average age of 55 ± 10 years. Fourteen implants were inserted in sinus augmented sites (open sinus elevation and Demineralized Freezed Bone Allograft  or DFDBA 6 months after healing (test group, and 16 implants were inserted into non-augmented  posterior areas of maxilla (control group. The implant stability quotient (ISQ for each implant was measured at the time of insertion (baseline, ISQ0 and at 1, 2 and 3 months later (ISQ1, ISQ2, ISQ3. Residual and augmented bone heights were also recorded. Results: The average residual bone height was 2.92 ± 0.63mm and 10.41 ± 1.46mm for the augmented bone height. The difference between ISQ values in the test and control groups was only significant at the baseline (p=0.023. No significant correlation was found between ISQ and bone height (residual and augmented, and there was no significant correlation between ISQ values and the implant diameter and length. In the test group, the differences between ISQ0 and ISQ1, ISQ1 and ISQ3 and ISQ2 and ISQ3 were all statistically significant (p=0.006, p=0.032, p=0.046. In the control group, the difference was only significant between ISQ0 and ISQ1 (p=0.002. Conclusion:  ISQ values were not statistically significant between implants inserted in natural and augmented bone six months after sinus

  10. Optical generation and control of quantum coherence in semiconductor nanostructures

    CERN Document Server

    Slavcheva, Gabriela

    2010-01-01

    The unprecedented control of coherence that can be exercised in quantum optics of atoms and molecules has stimulated increasing efforts in extending it to solid-state systems. One motivation to exploit the coherent phenomena comes from the emergence of the quantum information paradigm, however many more potential device applications ranging from novel lasers to spintronics are all bound up with issues in coherence. The book focuses on recent advances in the optical control of coherence in excitonic and polaritonic systems as model systems for the complex semiconductor dynamics towards the goal

  11. Steam generation control in Solar Invictus 53S - A parabolic dish solar collector for direct steam generation

    Science.gov (United States)

    Ali, Wajahat; Usman, Zubair; Jamil, Umer

    2017-06-01

    This paper presents a control methodology for steam generation at desired steam outlet conditions for the Solar Invictus 53S System. The system consists of a parabolic solar dish with an effective projected area of 51.6 m2 and a cavity type receiver which works as Once Through direct Solar Steam Generator (OTSSG). The challenge is to control the feedwater mass flow rate precisely in order to maintain the steam generation at desired steam conditions at the outlet of OTSSG. The controller must be robust to incorporate the varying external conditions like Direct Normal Irradiance (DNI), ambient temperature, soiling and wind speed. This paper formulates the control problem and presents a solution using two cascaded loops. In the first loop, feed forward mass flow rate to achieve the desired steam conditions is calculated. Feed forward control is implemented to give better disturbance rejection. For the mass flow rate calculated, a feedback loop is applied. The methodology is verified and tested in a simulated environment.

  12. Generation of entanglement in quantum parametric oscillators using phase control.

    Science.gov (United States)

    Gonzalez-Henao, J C; Pugliese, E; Euzzor, S; Abdalah, S F; Meucci, R; Roversi, J A

    2015-08-19

    The control of quantum entanglement in systems in contact with environment plays an important role in information processing, cryptography and quantum computing. However, interactions with the environment, even when very weak, entail decoherence in the system with consequent loss of entanglement. Here we consider a system of two coupled oscillators in contact with a common heat bath and with a time dependent oscillation frequency. The possibility to control the entanglement of the oscillators by means of an external sinusoidal perturbation applied to the oscillation frequency has been theoretically explored. We demonstrate that the oscillators become entangled exactly in the region where the classical counterpart is unstable, otherwise when the classical system is stable, entanglement is not possible. Therefore, we can control the entanglement swapping from stable to unstable regions by adjusting amplitude and phase of our external controller. We also show that the entanglement rate is approximately proportional to the real part of the Floquet coefficient of the classical counterpart of the oscillators. Our results have the intriguing peculiarity of manipulating quantum information operating on a classical system.

  13. power generation and control of a self excited squirrel cage ...

    African Journals Online (AJOL)

    HOD

    Its major drawbacks, however, are poor voltage and frequency regulation under variable load conditions. The aim of this paper is to investigate a feedback control strategy that takes a fraction of the output power and applies it to the prime mover as torque. The wind turbine is to be tied mechanically to the rotor of a squirrel ...

  14. Adaptive Backstepping Control Based on Floating Offshore High Temperature Superconductor Generator for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Feng Yang

    2014-01-01

    Full Text Available With the rapid development of offshore wind power, the doubly fed induction generator and permanent magnet synchronous generator cannot meet the increasing request of power capacity. Therefore, superconducting generator should be used instead of the traditional motor, which can improve generator efficiency, reduce the weight of wind turbines, and increase system reliability. This paper mainly focuses on nonlinear control in the offshore wind power system which is consisted of a wind turbine and a high temperature superconductor generator. The proposed control approach is based on the adaptive backstepping method. Its main purpose is to regulate the rotor speed and generator voltage, therefore, achieving the maximum power point tracking (MPPT, improving the efficiency of a wind turbine, and then enhancing the system’s stability and robustness under large disturbances. The control approach can ensure high precision of generator speed tracking, which is confirmed in both the theoretical analysis and numerical simulation.

  15. Third-generation percutaneous vertebral augmentation systems

    OpenAIRE

    Vanni, Daniele; Galzio, Renato; Kazakova, Anna; Pantalone, Andrea; Grillea, Giovanni; Bartolo, Marcello; Salini, Vincenzo; Magliani, Vincenzo

    2016-01-01

    Currently, there is no general consensus about the management of osteoporotic vertebral fractures (OVF). In the past, conservative treatment for at least one month was deemed appropriate for the majority of vertebral fractures. When pain persisted after conservative treatment, it was necessary to consider surgical interventions including: vertebroplasty for vertebral fractures with less than 30% loss of height of the affected vertebral body and kyphoplasty for vertebral fractures with greater...

  16. Hyperchaos generated from 3D chaotic systems using PI controller

    Science.gov (United States)

    Devi, V. R.; Farooq, Farsana; Gopakumar, K.

    2017-07-01

    Hyperchaotic systems have chaotic behavior with at least two positive Lyapunov exponents and the minimum required system dimension is four. In this paper, a 3D chaotic system is converted into hyperchaotic system using PI controller in the feedback path. Integral controller is responsible for increase in order of the system. The hyperchaotic nature is verified by the existence of two positive Lyapunov exponents and using bifurcation diagrams. The system is hyperchaotic in several different regions of the parameters. The result shows that this method can not only enhance or suppress chaotic behavior, but also induces chaos in non-chaotic parameter ranges. The proposed method is applied to a secure communication system by means of encryption and decryption of a message using hyperchaotic system.

  17. Intelligent Joint Admission Control for Next Generation Wireless Networks

    OpenAIRE

    Abdulqader M. Mohsen; Al-Akwaa, Fadhl M.; Mohammed M. Alkhawlani

    2012-01-01

    The Heterogeneous Wireless Network (HWN) integrates different wireless networks into one common network. The integrated networks often overlap coverage in the same wireless service areas, leading to the availability of a great variety of innovative services based on user demands in a cost-efficient manner. Joint Admission Control (JAC) handles all new or handoff service requests in the HWN. It checks whether the incoming service request to the selected Radio Access Network (RAN) by the initia...

  18. Routine sensor-augmented pump therapy in type 1 diabetes

    DEFF Research Database (Denmark)

    Nørgaard, Kirsten; Scaramuzza, Andrea; Bratina, Natasa

    2013-01-01

    Sensor-augmented pump (SAP) therapy can improve glycemic control, compared with multiple daily insulin injections or with insulin pump therapy alone, without increasing the risk of hypoglycemia.......Sensor-augmented pump (SAP) therapy can improve glycemic control, compared with multiple daily insulin injections or with insulin pump therapy alone, without increasing the risk of hypoglycemia....

  19. Chinese Calligraphy Writing for Augmenting Attentional Control and Working Memory of Older Adults at Risk of Mild Cognitive Impairment: A Randomized Controlled Trial.

    Science.gov (United States)

    Chan, Sam C C; Chan, Chetwyn C H; Derbie, Abiot Y; Hui, Irene; Tan, Davynn G H; Pang, Marco Y C; Lau, Stephen C L; Fong, Kenneth N K

    2017-01-01

    Nonpharmacological intervention for individuals with mild cognitive impairment (MCI) needs further investigation. Test efficacy of an eight-week Chinese calligraphy writing training course in improving attentional control and working memory. Ninety-nine participants with MCI were randomized into the eight-week calligraphy writing (n = 48) or control (tablet computer) training (n = 51). Outcomes of the interventions were attentional control, working memory, visual scan and processing speed. They were measured at baseline, post-training, and six-month follow-up. Calligraphy writing, when compared with control, significantly improved working memory as reflected from DST-Backward sequence (p = 0.009) and span scores (p = 0.002), and divided attention as reflected from CTT2 (p working memory (span: p working memory and to a lesser extent attentional control functions of patients with early MCI. They also demonstrate the usefulness of using mind-and-body practice for improving specific cognitive functions.

  20. Augmented marked graphs

    CERN Document Server

    Cheung, King Sing

    2014-01-01

    Petri nets are a formal and theoretically rich model for the modelling and analysis of systems. A subclass of Petri nets, augmented marked graphs possess a structure that is especially desirable for the modelling and analysis of systems with concurrent processes and shared resources.This monograph consists of three parts: Part I provides the conceptual background for readers who have no prior knowledge on Petri nets; Part II elaborates the theory of augmented marked graphs; finally, Part III discusses the application to system integration. The book is suitable as a first self-contained volume

  1. Prototyping Augmented Reality

    CERN Document Server

    Mullen, Tony

    2011-01-01

    Learn to create augmented reality apps using Processing open-source programming language Augmented reality (AR) is used all over, and you may not even realize it. Smartphones overlay data onto live camera views to show homes for sale, restaurants, or historical sites. American football broadcasts use AR to show the invisible first-down line on the field to TV viewers. Nike and Budweiser, among others, have used AR in ads. Now, you can learn to create AR prototypes using 3D data, Processing open-source programming language, and other languages. This unique book is an easy-to-follow guide on how

  2. The Augmented Book

    OpenAIRE

    Miller, D

    2015-01-01

    The Augmented Book: Sherwood Rise 30 January 2015 at 14:48 From 2012-13 I carried out practice-based research for the UNESCO future of the book project. The aim was to consider the future of the book using new media technology, particularly Augmented Reality (AR) on mobile phones. My research question was: How could digital media and physical books work together and interact to make a coherent story? I set about making an interactive story where participatory interaction with digital media vi...

  3. Motion planning and synchronized control of the dental arch generator of the tooth-arrangement robot.

    Science.gov (United States)

    Jiang, Jin-Gang; Zhang, Yong-De

    2013-03-01

    The traditional, manual method of reproducing the dental arch form is prone to numerous random errors caused by human factors. The purpose of this study was to investigate the automatic acquisition of the dental arch and implement the motion planning and synchronized control of the dental arch generator of the multi-manipulator tooth-arrangement robot for use in full denture manufacture. First, the mathematical model of the dental arch generator was derived. Then the kinematics and control point position of the dental arch generator of the tooth arrangement robot were calculated and motion planning of each control point was analysed. A hardware control scheme is presented, based on the industrial personal computer and control card PC6401. In order to gain single-axis, precise control of the dental arch generator, we studied the control pulse realization of high-resolution timing. Real-time, closed-loop, synchronous control was applied to the dental arch generator. Experimental control of the dental arch generator and preliminary tooth arrangement were gained by using the multi-manipulator tooth-arrangement robotic system. The dental arch generator can automatically generate a dental arch to fit a patient according to the patient's arch parameters. Repeated positioning accuracy is 0.12 mm for the slipways that drive the dental arch generator. The maximum value of single-point error is 1.83 mm, while the arc-width direction (x axis) is -33.29 mm. A novel system that generates the dental arch has been developed. The traditional method of manually determining the dental arch may soon be replaced by a robot to assist in generating a more individual dental arch. The system can be used to fabricate full dentures and bend orthodontic wires. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Control design for a wind turbine-generator using output feedback

    Science.gov (United States)

    Javid, S. H.; Murdoch, A.; Winkelman, J. R.

    1981-01-01

    The modeling and approach to control design for a large horizontal axis wind turbine (WT) generator are presented. The control design is based on a suboptimal output regulator which allows coordinated control of WT blade pitch angle and field voltage for the purposes of regulating electrical power and terminal voltage. Results of detailed non-linear simulation tests of this controller are shown.

  5. Webizing mobile augmented reality content

    Science.gov (United States)

    Ahn, Sangchul; Ko, Heedong; Yoo, Byounghyun

    2014-01-01

    This paper presents a content structure for building mobile augmented reality (AR) applications in HTML5 to achieve a clean separation of the mobile AR content and the application logic for scaling as on the Web. We propose that the content structure contains the physical world as well as virtual assets for mobile AR applications as document object model (DOM) elements and that their behaviour and user interactions are controlled through DOM events by representing objects and places with a uniform resource identifier. Our content structure enables mobile AR applications to be seamlessly developed as normal HTML documents under the current Web eco-system.

  6. Nanoscale control of heat generation with plasmonic nanostructures

    OpenAIRE

    Morales Dalmau, Jordi

    2013-01-01

    [ANGLÈS] During the last 25 years nanotechnology has become a transvers field either in research and everyday's live. In this work we present a method which can control temperature down to nanoscale thanks to plasmonic properties of gold nanoparticles. Moreover, we open a new field named "thermal engineering" which has the aim of performing adaptable thermal maps for every purpose at nanoscale. [CASTELLÀ] Durante los últimos 25 años la nanotecnología se ha situado como un importante campo ...

  7. Frequency Control Problems in the Power System with Massive Penetration of Distributed Generation

    OpenAIRE

    Čuvičins, V; Sauhats, A; Strelkovs, V; Deuse, J

    2008-01-01

    The paper presents a study of the impact of increasing amount of distributed generation resources (DER) on control and management of transmission and distribution systems. Paper considers how DER penetration influences frequency control during normal operational conditions. Controllability of different types of DER associated with frequency control is considered. List of power system parameters influencing frequency control is presented. Case study is based on analysis of frequency control a...

  8. ‎ Lamotrigine Augmentation versus Placebo in Serotonin ‎Reuptake Inhibitors-‎Resistant Obsessive-Compulsive Disorder: ‎A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Mohammadrasoul Khalkhali

    2016-06-01

    Full Text Available Objective: Serotonin reuptake inhibitors are frequently used in first-line treatments for patients ‎with obsessive-compulsive disorder. Nevertheless, many of these patients do not ‎respond well to initial therapy. The hypothesis of glutamatergic dysfunction in specific ‎brain regions has been proposed in the pathophysiology of obsessive-compulsive ‎disorder. This study was designed to evaluate the possible efficacy of lamotrigine, a ‎glutamatergic agent in Serotonin reuptake inhibitors-resistant patients with obsessive-‎compulsive disorder.‎Method: This study was a 12-week, double blind, randomized, placebo-controlled trial of ‎adjunctive fixed-doses of lamotrigine (100 mg to Serotonin reuptake inhibitors therapy ‎in obsessive-compulsive disorder. Eligible subjects who had a total Y-BOCS of 21 or ‎above were randomly assigned to receive adjunctive treatment with either lamotrigine ‎‎(n = 26, or placebo (n = 27. Response to lamotrigine was defined as clinical ‎improvement (>25% decrease in the total Y-BOCS score, which was administered at ‎weeks 0, 8 and 12.‎Results: At the endpoint (week 12, significant differences were observed in obsession, ‎compulsion, and total Y-BOCS scores comparing lamotrigine to placebo (P = 0.01, ‎‎0.005 and 0.007 respectively. The mean reduction in obsession, compulsion and total ‎scores in lamotrigine group was about 4.15, 4.50 and 8.73, respectively. Similarly, the ‎mean reductions in the placebo group were 2.52, 2.56 and 5.07. Effect sizes for efficacy ‎measures were calculated by Cohen’s d, and it was calculated as 0.54 for the total ‎YBOCS.‎Conclusion: Our findings provide evidence that this augmentation is well tolerated and may be an ‎effective strategy for patients with refractory obsessive-compulsive disorder.‎‎

  9. Efficacy and safety of oxytocin augmentation therapy for schizophrenia: an updated systematic review and meta-analysis of randomized, placebo-controlled trials.

    Science.gov (United States)

    Oya, Kazuto; Matsuda, Yuki; Matsunaga, Shinji; Kishi, Taro; Iwata, Nakao

    2016-08-01

    The aim of this study was to perform a systematic review and an updated and comprehensive meta-analysis of oxytocin augmentation therapy in patients with schizophrenia who received antipsychotic agents. Data published up to 07/11/2015 were obtained from PubMed, PsycINFO, and Cochrane Library databases. We conducted a systematic review and meta-analysis of patients' data from randomized controlled trials (RCTs) comparing oxytocin with placebo. Relative risk (RR), standardized mean difference (SMD), and 95 % confidence intervals (95 % CI) based on the random-effects model were calculated. We included seven RCTs; the total sample size was 206 patients. Oxytocin was superior to placebo for decreasing the Positive and Negative Syndrome Scale (PANSS) general subscale scores (SMD = -0.44, 95 % CI -0.82 to -0.06, p = 0.02, I (2) = 0 %, N = 4, n = 112); however, it was not different from placebo for total symptoms (SMD = -0.46, 95 % CI -1.20 to 0.28, p = 0.22, I (2) = 80 %, N = 6, n = 162), positive symptoms (SMD = -0.18, 95 % CI -0.87 to 0.51, p = 0.60, I (2) = 81 %, N = 6, n = 192), and negative symptoms (SMD = -0.34, 95 % CI -0.76 to 0.08, p = 0.12, I (2) = 55 %, N = 7, n = 214). However, a sensitivity analysis including only oxytocin administration on consecutive days studies was superior to placebo in negative symptoms (SMD = -0.44, 95 % CI -0.87 to -0.01, p = 0.04, I (2) = 51 %, N = 6 n = 192). There were no significant differences for all-cause discontinuation (RR = 1.02) and individual side effects such as headache and dizziness between oxytocin and placebo. Oxytocin may improve PANSS general subscale scores in schizophrenia and seems to be well tolerated. However, because the number of studies in the current analysis was small, further study will be required using larger sample sizes.

  10. Towards Pervasive Augmented Reality: Context-Awareness in Augmented Reality.

    Science.gov (United States)

    Grubert, Jens; Langlotz, Tobias; Zollmann, Stefanie; Regenbrecht, Holger

    2017-06-01

    Augmented Reality is a technique that enables users to interact with their physical environment through the overlay of digital information. While being researched for decades, more recently, Augmented Reality moved out of the research labs and into the field. While most of the applications are used sporadically and for one particular task only, current and future scenarios will provide a continuous and multi-purpose user experience. Therefore, in this paper, we present the concept of Pervasive Augmented Reality, aiming to provide such an experience by sensing the user's current context and adapting the AR system based on the changing requirements and constraints. We present a taxonomy for Pervasive Augmented Reality and context-aware Augmented Reality, which classifies context sources and context targets relevant for implementing such a context-aware, continuous Augmented Reality experience. We further summarize existing approaches that contribute towards Pervasive Augmented Reality. Based our taxonomy and survey, we identify challenges for future research directions in Pervasive Augmented Reality.

  11. Approaches for controlling air pollutants and their environmental impacts generated from coal-based electricity generation in China.

    Science.gov (United States)

    Xu, Changqing; Hong, Jinglan; Ren, Yixin; Wang, Qingsong; Yuan, Xueliang

    2015-08-01

    This study aims at qualifying air pollutants and environmental impacts generated from coal-based power plants and providing useful information for decision makers on the management of coal-based power plants in China. Results showed that approximately 9.03, 54.95, 62.08, and 12.12% of the national carbon dioxide, sulfur dioxide, nitrogen oxides, and particulate matter emissions, respectively, in 2011were generated from coal-based electricity generation. The air pollutants were mainly generated from east China because of the well-developed economy and energy-intensive industries in the region. Coal-washing technology can simply and significantly reduce the environmental burden because of the relativity low content of coal gangue and sulfur in washed coal. Optimizing the efficiency of raw materials and energy consumption is additional key factor to reduce the potential environmental impacts. In addition, improving the efficiency of air pollutants (e.g., dust, mercury, sulfur dioxide, nitrogen oxides) control system and implementing the strict requirements on air pollutants for power plants are important ways for reducing the potential environmental impacts of coal-based electricity generation in China.

  12. Augmented Reality Binoculars.

    Science.gov (United States)

    Oskiper, Taragay; Sizintsev, Mikhail; Branzoi, Vlad; Samarasekera, Supun; Kumar, Rakesh

    2015-05-01

    In this paper we present an augmented reality binocular system to allow long range high precision augmentation of live telescopic imagery with aerial and terrain based synthetic objects, vehicles, people and effects. The inserted objects must appear stable in the display and must not jitter and drift as the user pans around and examines the scene with the binoculars. The design of the system is based on using two different cameras with wide field of view and narrow field of view lenses enclosed in a binocular shaped shell. Using the wide field of view gives us context and enables us to recover the 3D location and orientation of the binoculars much more robustly, whereas the narrow field of view is used for the actual augmentation as well as to increase precision in tracking. We present our navigation algorithm that uses the two cameras in combination with an inertial measurement unit and global positioning system in an extended Kalman filter and provides jitter free, robust and real-time pose estimation for precise augmentation. We have demonstrated successful use of our system as part of information sharing example as well as a live simulated training system for observer training, in which fixed and rotary wing aircrafts, ground vehicles, and weapon effects are combined with real world scenes.

  13. Collaboration in Augmented Reality

    NARCIS (Netherlands)

    Lukosch, S.; Billinghurst, M.; Alem, L.; Kiyokawa, K.

    2015-01-01

    Augmented Reality (AR) is a technology that allows users to view and interact in real time with virtual images seamlessly superimposed over the real world. AR systems can be used to create unique collaborative experiences. For example, co-located users can see shared 3D virtual objects that they

  14. Augmented reality som wearable

    DEFF Research Database (Denmark)

    Buhl, Mie; Rahn, Annette

    2015-01-01

    Artiklen omhandler design og implementering af Augmented Reality (AR) i form af en wearable i sygeplejerskeuddannelsens anatomiundervisning, mere specifikt undervisning i lungeanatomi og respiration, med fokus på potentialer for visuel læring. Projektet undersøger, hvordan en udviklet AR...

  15. Augmented Reality og kulturarv

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Kirkedahl Lysholm

    2013-01-01

    Museerne står overfor at skulle omfavne den digitale kultur i håndteringen af den store mængde viden, institutionerne repræsenterer. Augmented Reality-systemer forbinder ved hjælp af moderne teknologi det virtuelle med det virkelige, og kan derfor synes som en oplagt anvendelsesmulighed i...

  16. Augmented Reality i naturfagsundervisningen

    DEFF Research Database (Denmark)

    Radmer, Ole; Surland, Mogens; Nielsen, Birgitte Lund

    Augmented Reality (AR) giver ny mulighed for, at elever kan lave undersøgelser i naturfag med enkel teknologi, hvor animationer og simulationer kobles med det virkelige fænomen. I workshoppen kan I afprøve AR eksempler, udviklet i et internationalt EU projekt. Der vil være noget, der direkte kan...

  17. Next generation ATCA control infrastructure for the CMS Phase-2 upgrades

    OpenAIRE

    Smith, Wesley

    2017-01-01

    A next generation control infrastructure to be used in Advanced TCA (ATCA) blades at the CMS experiment is being designed and tested. Several ATCA systems are being prepared for the High-Luminosity LHC (HL-LHC) and will be installed at CMS during technical stops. The next generation control infrastructure will provide all the necessary hardware, firmware and software required in these systems, decreasing development time. It includes an Intelligent Platform Management Controller (IPMC), a Mod...

  18. Handling Occlusions for Robust Augmented Reality Systems

    Directory of Open Access Journals (Sweden)

    Madjid Maidi

    2010-01-01

    Full Text Available In Augmented Reality applications, the human perception is enhanced with computer-generated graphics. These graphics must be exactly registered to real objects in the scene and this requires an effective Augmented Reality system to track the user's viewpoint. In this paper, a robust tracking algorithm based on coded fiducials is presented. Square targets are identified and pose parameters are computed using a hybrid approach based on a direct method combined with the Kalman filter. An important factor for providing a robust Augmented Reality system is the correct handling of targets occlusions by real scene elements. To overcome tracking failure due to occlusions, we extend our method using an optical flow approach to track visible points and maintain virtual graphics overlaying when targets are not identified. Our proposed real-time algorithm is tested with different camera viewpoints under various image conditions and shows to be accurate and robust.

  19. Handling Occlusions for Robust Augmented Reality Systems

    Directory of Open Access Journals (Sweden)

    Maidi Madjid

    2010-01-01

    Full Text Available Abstract In Augmented Reality applications, the human perception is enhanced with computer-generated graphics. These graphics must be exactly registered to real objects in the scene and this requires an effective Augmented Reality system to track the user's viewpoint. In this paper, a robust tracking algorithm based on coded fiducials is presented. Square targets are identified and pose parameters are computed using a hybrid approach based on a direct method combined with the Kalman filter. An important factor for providing a robust Augmented Reality system is the correct handling of targets occlusions by real scene elements. To overcome tracking failure due to occlusions, we extend our method using an optical flow approach to track visible points and maintain virtual graphics overlaying when targets are not identified. Our proposed real-time algorithm is tested with different camera viewpoints under various image conditions and shows to be accurate and robust.

  20. Surface Control in Pursuit of Next-Generation Batteries

    Science.gov (United States)

    Gordin, Mikhail L.

    Lithium-ion batteries have had a dramatic impact on the development of technology over the last few decades, enabling new developments like the revolution in mobile devices. However, meeting the needs of today's technological frontiers, such as electric vehicles and grid-scale energy storage, will require radical new battery designs. Although many factors contribute to the viability of new designs, surface features are often a critical component. With that in mind, the work herein delves into analysis and control of surface features in two promising battery systems: lithium-sulfur batteries and phosphorous anodes for sodium-ion batteries. Lithium-sulfur batteries often suffer from mediocre capacity, poor cycling stability, low efficiency, and high self-discharge caused by the dissolution and diffusion of lithium polysulfides and their side-reactions with the lithium anode. Two approaches for controlling this behavior are thus presented. In Chapter 2, mesoporous nitrogen-doped carbon is shown to have dramatically enhanced ability to adsorb lithium polysulfides compared with undoped mesoporous carbon; this was found to significantly improve both the cyclability and the capacity of the battery. In Chapter 3, a new electrolyte additive, bis(2,2,2-trifluoroethyl) ether, is shown to help form a more robust anode solid-electrolyte interphase (SEI) and thus to mitigate self-discharge over prolonged a rest at an elevated temperature. Phosphorus anodes, in contrast, experience severe volume change ( 300%) with cycling, leading to particle fracture and SEI instability. Fluoroethylene carbonate has been shown to be a good electrolyte additive for mitigating the capacity fading caused by these effects. In Chapter 4, the changes in the SEI growth and composition brought about by FEC are investigated in detail by impedance spectroscopy, electron microscopy, and spectroscopic techniques. In addition, it is shown that severe sodium metal deposition can occur on phosphorus

  1. Control of microbially generated hydrogen sulfide in produced waters

    Energy Technology Data Exchange (ETDEWEB)

    Burger, E.D.; Vance, I.; Gammack, G.F.; Duncan, S.E.

    1995-12-31

    Production of hydrogen sulfide in produced waters due to the activity of sulfate-reducing bacteria (SRB) is a potentially serious problem. The hydrogen sulfide is not only a safety and environmental concern, it also contributes to corrosion, solids formation, a reduction in produced oil and gas values, and limitations on water discharge. Waters produced from seawater-flooded reservoirs typically contain all of the nutrients required to support SRB metabolism. Surface processing facilities provide a favorable environment in which SRB flourish, converting water-borne nutrients into biomass and H{sub 2}S. This paper will present results from a field trial in which a new technology for the biochemical control of SRB metabolism was successfully applied. A slip stream of water downstream of separators on a produced water handling facility was routed through a bioreactor in a side-steam device where microbial growth was allowed to develop fully. This slip stream was then treated with slug doses of two forms of a proprietary, nonbiocidal metabolic modifier. Results indicated that H{sub 2}S production was halted almost immediately and that the residual effect of the treatment lasted for well over one week.

  2. Control-Oriented First Principles-Based Model of a Diesel Generator

    DEFF Research Database (Denmark)

    Knudsen, Jesper Viese; Bendtsen, Jan Dimon; Andersen, Palle

    2016-01-01

    This paper presents the development of a control-oriented tenth-order nonlinear model of a diesel driven generator set, using first principles modeling. The model provides physical system insight, while keeping the complexity at a level where it can be a tool for future design of improved automatic...... generation control (AGC), by including important nonlinearities of the machine. The nonlinearities are, as would be expected for a generator, primarily of bilinear nature. Validation of the model is done with measurements on a 60 kVA/48 kW diesel driven generator set in island operation during steps...

  3. Human Performance Assessments when Using Augmented Reality for Navigation

    National Research Council Canada - National Science Library

    Goldiez, Brian F; Saptoka, Nabin; Aedunuthula, Prashanth

    2006-01-01

    Human performance executing search and rescue type of navigation is one area that can benefit from augmented reality technology when the proper computer generated information is added to a real scene...

  4. An optimum magnetic control torque generation of a momentum bias satellite

    Directory of Open Access Journals (Sweden)

    N Suhadis

    2016-09-01

    Full Text Available This paper describes a comparison study of magnetic attitude control torque generation performance of a momentum bias satellite operated in Low Earth Orbit (LEO with various orbit inclinations. The satellite is equipped with two magnetic torquers that are placed along the +x and +y axes where magnetic control torque is generated when these magnetic torquers couple with the geomagnetic fields and its vector direction is perpendicular to both the magnetic fields. The control algorithm was structured using a proportional (P controller for satellite attitudes/nutation control and a proportional-integral (PI controller for managing the excess angular momentum on the momentum wheel. The structured control algorithm is simulated for 23°, 53° and 83° orbit inclinations and the generated attitude torque performances are compared to see how the variation of the satellite orbit affects the satellite's attitude torque generation as the magnitude and direction of the geomagnetic fields vary with respect to the altitude and latitude while the magnitude and direction of the magnetic fields generated by the magnetic torquers vary with respect to the orbital motion. Results from simulation show that the higher orbit inclination generates optimum magnetic attitude control torque. Note that this work is the extension of the previous work published in The International Journal of Multiphysics [1].

  5. Treatment of the atrophic edentulous maxilla: short implants versus bone augmentation for placing longer implants. Five-month post-loading results of a pilot randomised controlled trial.

    Science.gov (United States)

    Felice, Pietro; Soardi, Elisa; Pellegrino, Gerardo; Pistilli, Roberto; Marchetti, Claudio; Gessaroli, Manlio; Esposito, Marco

    2011-01-01

    To evaluate whether short (5 to 8.5 mm) dental implants could be a suitable alternative to longer (>11.5 mm) implants placed in atrophic maxillae augmented with autogenous bone for supporting dental prostheses. Twenty-eight patients with fully edentulous atrophic maxillae having 5 to 9 mm of residual crestal bone height at least 5 mm thick, as measured on computerised tomography scans, were randomised into two groups either to receive 4 to 8 short (5 to 8.5 mm) implants (15 patients) or autogenous bone from the iliac crest to allow the placement of at least 11.5 mmlong implants (13 patients). Bone blocks and the windows at maxillary sinuses were covered with rigid resorbable barriers. Grafts were left to heal for 4 months before placing implants, which were submerged. After 4 months, provisional reinforced acrylic prostheses or bar-retained overdentures were delivered. Provisional prostheses were replaced, after 4 months, by definitive screw-retained metal-resin cross-arch fixed dental prostheses. Outcome measures were: prosthesis and implant failures, any complications (including prolonged postoperative pain) and patient satisfaction. All patients were followed for 5 months after loading. All patients could be rehabilitated with implant-supported prostheses and none dropped out. One bilateral sinus lift procedure failed due to infection, though short implants could be placed. One implant failed in the augmented group versus 2 short implants in 2 patients. All failures occurred before loading. Significantly more complications occurred in augmented patients: 8 complications occurred in 5 augmented patients (all complained of pain 1 month after bone harvesting from the iliac crest). No complications occurred in the short implant group. All patients were fully satisfied with the treatment and would do it again. This pilot study suggests that short implants may be a suitable, cheaper and faster alternative to longer implants placed in bone augmented with autogenous

  6. Adaptive sliding mode control of interleaved parallel boost converter for fuel cell energy generation system

    DEFF Research Database (Denmark)

    El Fadil, H.; Giri, F.; Guerrero, Josep M.

    2013-01-01

    This paper deals with the problem of controlling energy generation systems including fuel cells (FCs) and interleaved boost power converters. The proposed nonlinear adaptive controller is designed using sliding mode control (SMC) technique based on the system nonlinear model. The latter accounts...

  7. A control architecture to coordinate distributed generators and active power filters coexisting in a microgrid

    DEFF Research Database (Denmark)

    Hashempour, Mohammad M.; Savaghebi, Mehdi; Quintero, Juan Carlos Vasquez

    2016-01-01

    This paper proposes a control architecture of distributed generators (DGs) inverters and shunt active power filters (APFs) in microgrids to compensate voltage harmonics in a coordinated way. For this, a hierarchical control structure is proposed that includes two control levels. The primary (local...

  8. A Control Architecture to Coordinate Distributed Generators and Active Power Filters Coexisting in a Microgrid

    DEFF Research Database (Denmark)

    Hashempour, Mohammad M.; Firoozabadi, Mehdi Savaghebi; Quintero, Juan Carlos Vasquez

    2016-01-01

    This paper proposes a control architecture of distributed generators (DGs) inverters and shunt active power filters (APFs) in microgrids to compensate voltage harmonics in a coordinated way. For this, a hierarchical control structure is proposed that includes two control levels. The primary (local...

  9. AR DOC: Augmented reality documentaries

    DEFF Research Database (Denmark)

    Vistisen, Peter

    2014-01-01

    Augmented Reality Documentaries (AR DOC) er et ’lille’ Shareplay projekt (ansøgte midler augmented reality cross media løsninger, til at skabe engagerende publikumsformidling...... indenfor oplevelsesindustrien. Projektet har genereret ny viden omkring, hvordan fysisk og digital formidling kan understøttes via Augmented Reality som formidlingsformat....

  10. Approaches to the automatic generation and control of finite element meshes

    Science.gov (United States)

    Shephard, Mark S.

    1987-01-01

    The algorithmic approaches being taken to the development of finite element mesh generators capable of automatically discretizing general domains without the need for user intervention are discussed. It is demonstrated that because of the modeling demands placed on a automatic mesh generator, all the approaches taken to date produce unstructured meshes. Consideration is also given to both a priori and a posteriori mesh control devices for automatic mesh generators as well as their integration with geometric modeling and adaptive analysis procedures.

  11. Transaxillary Endoscopic Breast Augmentation

    Directory of Open Access Journals (Sweden)

    Hyung-Bo Sim

    2014-09-01

    Full Text Available The axillary technique is the most popular approach to breast augmentation among Korean women. Transaxillary breast augmentation is now conducted with sharp electrocautery dissection under direct endoscopic vision throughout the entire process. The aims of this method are clear: both a bloodless pocket and a sharp non-traumatic dissection. Round textured or anatomical cohesive gel implants have been used to make predictable well-defined inframammary creases because textured surface implants demonstrated a better stability attributable to tissue adherence compared with smooth surface implants. The axillary endoscopic technique has greatly evolved, and now the surgical results are comparable to those with the inframammary approach. The author feels that this technique is an excellent choice for young patients with an indistinct or absent inframammary fold, who do not want a scar in the aesthetic unit of their chest.

  12. FUZZY LOGIC BASED INTELLIGENT CONTROL OF A VARIABLE SPEED CAGE MACHINE WIND GENERATION SYSTEM

    Science.gov (United States)

    The report gives results of a demonstration of the successful application of fuzzy logic to enhance the performance and control of a variable-speed wind generation system. A squirrel cage induction generator feeds the power to either a double-sided pulse-width modulation converte...

  13. Revisiting the Praise Paradox: An Action-Control Perspective on Negative Affect and Idea Generation

    DEFF Research Database (Denmark)

    Lomberg, Carina; Klyver, Kim

    negative affect and idea generation. The patterns we identify provide a detailed understanding of how individuals’ action control determines the kind of feedback needed to increase originality. Thereby, we provide important new insights for research on the generation of original ideas that are necessary...

  14. Flicker Mitigation Strategy for a Doubly Fed Induction Generator by Torque Control

    DEFF Research Database (Denmark)

    Zhang, Yunqian; Hu, Weihao; Chen, Zhe

    2014-01-01

    induction generator is presented to investigate the flicker mitigation. Taking advantage of the large inertia of the wind turbine rotor, a generator torque control (GTC) strategy is proposed, so that the power oscillation is stored as the kinetic energy of the wind turbine rotor, thus the flicker emission...

  15. A GA-fuzzy automatic generation controller for interconnected power system

    CSIR Research Space (South Africa)

    Boesack, CD

    2011-10-01

    Full Text Available -1 Fourth International Workshop on Advanced Computational Intelligence Wuhan, Hubei, China; October 19-21, 2011 A GA-Fuzzy Automatic Generation Controller for Interconnected Power Systems Craig D. Boesack,Tshilidzi Marwal, and Fulufhelo V. Nelwamondo...

  16. Research on the control strategy of distributed energy resources inverter based on improved virtual synchronous generator

    OpenAIRE

    Gao, Changwei; Liu, Xiaoming; Chen, Hai

    2017-01-01

    This paper focus on the power fluctuations of the virtual synchronous generator(VSG) during the transition process. An improved virtual synchronous generator(IVSG) control strategy based on feed-forward compensation is proposed. Adjustable parameter of the compensation section can be modified to achieve the goal of reducing the order of the system. It can effectively suppress the power fluctuations of the VSG in transient process. To verify the effectiveness of the proposed control strategy f...

  17. Impact Assessment of Various Methods for Control of Synchronous Generator Excitation on Quality of Transient Processes

    Directory of Open Access Journals (Sweden)

    Y. D. Filipchik

    2011-01-01

    Full Text Available The paper considers an impact of various methods for control of an exciting current pertaining to a synchronous generator on the nature of transient processes. A control algorithm for the exciting current in relation to changes in sliding and acceleration of a generator rotor has been proposed in the paper. The algorithm makes it possible to improve quality of the transient processes due to reduction of oscillation range concerning as an active power so a δ-angle as well.

  18. Augmented reality services

    Directory of Open Access Journals (Sweden)

    Tomáš Koubek

    2013-01-01

    Full Text Available We assume that one of the key reasons is in the difference between a standalone application and a web service. Both architectures have some advantages and disadvantages. The Standalone application (e.g. Nokia/OVI Maps provides the required functionality. From the user point of view, main asset of this “offline” approach is network connectivity independence. However, this kind of applications must be upgraded manually. Moreover, it is hard to get any data about the application usage because it requires additional actions from the user – data are usually acquired through conventional ways, such as email or web forms.The online service such as Google Maps (including its mobile application can offer the same functionality as the offline application. Nevertheless, a permanent connection to provider servers is necessary. This can be taken as a drawback. On the other hand, usage data collection is easier and can be done without the user intervention. The data collection provides a valuable analysis basis of the user habits and needs. This analysis is necessary for design of a complex “user” based solutions such as Google Now.Augmented reality applications are usually based on the first mentioned approach. In this article, we describe our model of augmented reality as a service and compare its features with standalone solutions. Further, other important key aspects for large emergence of augmented reality services in a mainstream market are discussed.

  19. Research on grid connection control technology of double fed wind generator

    Science.gov (United States)

    Ling, Li

    2017-01-01

    The composition and working principle of variable speed constant frequency doubly fed wind power generation system is discussed in this thesis. On the basis of theoretical analysis and control on the modeling, the doubly fed wind power generation simulation control system is designed based on a TMS320F2407 digital signal processor (DSP), and has done a large amount of experimental research, which mainly include, variable speed constant frequency, constant pressure, Grid connected control experiment. The running results show that the design of simulation control system is reasonable and can meet the need of experimental research.

  20. Next generation ATCA control infrastructure for the CMS Phase-2 upgrades

    CERN Document Server

    Smith, Wesley

    2017-01-01

    A next generation control infrastructure to be used in Advanced TCA (ATCA) blades at the CMS experiment is being designed and tested. Several ATCA systems are being prepared for the High-Luminosity LHC (HL-LHC) and will be installed at CMS during technical stops. The next generation control infrastructure will provide all the necessary hardware, firmware and software required in these systems, decreasing development time. It includes an Intelligent Platform Management Controller (IPMC), a Module Management Controller (MMC) and an Embedded Linux Mezzanine (ELM) processing card. The chosen architectures, their testability, integration and the advantages over existing solutions will be discussed.

  1. Computer-controlled High Resolution Arbitrary Waveform Generator (HRAWG) for Focusing Beamforming Applications

    Science.gov (United States)

    Assef, Amauri Amorin; Maia, Joaquim Miguel; Costa, Eduardo Tavares

    In advanced ultrasound imaging systems, expensive high-end integrated analog front-ends have been traditionally used to support generation of arbitrary transmit waveforms, in addition to transmit focusing and apodization control. In this paper, we present a cost-effective computer-controlled reconfigurable high-resolution arbitrary waveform generator (HRAWG) that has been designed for ultrasound research, development and teaching at the Federal University of Technology (UTFPR), Brazil. The 8-channel transmit beamformer is fully controlled by a host computer in which a Matlab GUI with the Field II simulation program, allows easy and accurate control over the transmission parameters such as waveform, amplitude apodization and timing.

  2. Photonic generation of frequency-sextupled microwave signal without filter or precise phase control

    Science.gov (United States)

    Chen, Yiwang; Teng, Yichao; Zhang, Baofu; Zhang, Pin; Li, Jianhua; Lu, Lin

    2017-08-01

    A photonic approach for frequency-sextupled microwave signal generation without filter or precise phase control is demonstrated by computer simulations and experiments. Without any filter, a frequency-sextupled microwave signal is generated by adjusting bias voltages of the cascade modulators. This structure largely reduces the dependence of particular phase relation that is built between the different modulated signals. The approach is verified by simulations and experiments, and stable 18- and 24-GHz frequency-sextupled signals are generated by 3 and 4 GHz local signals without filter or precise phase control.

  3. Coherent control in quantum open systems: An approach for accelerating dissipation-based quantum state generation

    Science.gov (United States)

    Chen, Ye-Hong; Shi, Zhi-Cheng; Song, Jie; Xia, Yan; Zheng, Shi-Biao

    2017-10-01

    In this paper, we propose an approach to accelerate the dissipation dynamics for quantum state generation with Lyapunov control. The strategy is to add target-state-related coherent control fields into the dissipation process to intuitively improve the evolution speed. By applying the current approach, without losing the advantages of dissipation dynamics, the target stationary states can be generated in a much shorter time as compared to that via traditional dissipation dynamics. As a result, the current approach containing the advantages of coherent unitary dynamics and dissipation dynamics allows for a significant improvement in quantum state generation.

  4. Revisiting the Praise Paradox: An Action-Control Perspective on Negative Affect and Idea Generation

    DEFF Research Database (Denmark)

    Lomberg, Carina; Klyver, Kim

    Building on personality-systems-interactions (PSI) theory, we analyze how individuals’ action control influences the originality of the ideas they generate when experiencing negative affect. We use a pre-test/post-test experimental design with 328 participants that captures dynamic effects between...... negative affect and idea generation. The patterns we identify provide a detailed understanding of how individuals’ action control determines the kind of feedback needed to increase originality. Thereby, we provide important new insights for research on the generation of original ideas that are necessary...

  5. Chemical Characterization of Pineapple Leaf Residue Chars generated by Controlled Combustion and by open burning

    Directory of Open Access Journals (Sweden)

    Leng L.Y.

    2017-01-01

    Full Text Available This study was undertaken to compare the chemical characteristics of pineapple leave residues (PLRs char generated by controlled combustion and by open burning. The properties of char generated by control combustion (CC and open burning (OB varied, due to differences in the production process. The total N, K and surface area of the char generated by CC were significantly higher than the OB. The results indicate that the CC process was better to be applied as a soil amendment than was the OB process.

  6. Reversible photochemical control of singlet oxygen generation using diarylethene photochromic switches.

    Science.gov (United States)

    Hou, Lili; Zhang, Xiaoyan; Pijper, Thomas C; Browne, Wesley R; Feringa, Ben L

    2014-01-22

    Reversible noninvasive control over the generation of singlet oxygen is demonstrated in a bicomponent system comprising a diarylethene photochromic switch and a porphyrin photosensitizer by selective irradiation at distinct wavelengths. The efficient generation of singlet oxygen by the photosensitizer is observed when the diarylethene unit is in the colorless open form. Singlet oxygen generation is not observed when the diarylethene is converted to the closed form. Irradiation of the closed form with visible light (>470 nm) leads to full recovery of the singlet oxygen generating ability of the porphyrin sensitizer.

  7. Outpatient 60-hour day-and-night glucose control with dual-hormone artificial pancreas, single-hormone artificial pancreas, or sensor-augmented pump therapy in adults with type 1 diabetes: An open-label, randomised, crossover, controlled trial.

    Science.gov (United States)

    Haidar, Ahmad; Messier, Virginie; Legault, Laurent; Ladouceur, Martin; Rabasa-Lhoret, Rémi

    2017-05-01

    To assess whether the dual-hormone (insulin and glucagon) artificial pancreas reduces hypoglycaemia compared to the single-hormone (insulin alone) artificial pancreas in outpatient settings during the day and night. In a randomized, three-way, crossover trial we compared the dual-hormone artificial pancreas, the single-hormone artificial pancreas and sensor-augmented pump therapy (control) in 23 adults with type 1 diabetes. Each intervention was applied from 8 AM Day 1 to 8 PM Day 3 (60 hours) in outpatient free-living conditions. The primary outcome was time spent with sensor glucose levels below 4.0 mmol/L. A P value of less than .017 was regarded as significant. The median difference between the dual-hormone system and the single-hormone system was -2.3% (P = .072) for time spent below 4.0 mmol/L, -1.3% (P = .017) for time below 3.5 mmol/L, and -0.7% (P = .031) for time below 3.3 mmol/L. Both systems reduced (P artificial pancreas had the lowest risk of hypoglycaemia, but the differences were not statistically significant. Larger studies are needed. © 2017 John Wiley & Sons Ltd.

  8. Torque control of synchronous and induction generators for variable speed operation of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ola; Ulen, E. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-01

    The aim of this paper is to investigate variable speed electrical systems. Synchronous generators with diode rectifiers and line-commutated thyristor converters are compared with induction generators with force commutated transistor converters and scalar control. The system characteristics are examined regarding possible speed of response (bandwidth) of the torque control, including the sensitivity to disturbances for the drive train and also the possibility to get damping of the drive train resonance. Analyses, simulations and laboratory tests with a 40 kW machine set-up have been performed. The investigation shows that the system with synchronous generator is well suited for wind power applications. A rapid standard DC-current regulator is included in the torque control and can be used for damping of the resonance. The torque control has a bandwidth up to about 3 Hz and the DC-voltage controller up to about 1 Hz. The system with induction generator with scalar control (no transformations) is more difficult to control. A linear approach is only possible up to about 1.5 Hz. In this region it turns out that the behaviour can be visualized as an added inertia on the generator side that can be rather big. 4 refs, 9 figs

  9. Model predictive control system and method for integrated gasification combined cycle power generation

    Science.gov (United States)

    Kumar, Aditya; Shi, Ruijie; Kumar, Rajeeva; Dokucu, Mustafa

    2013-04-09

    Control system and method for controlling an integrated gasification combined cycle (IGCC) plant are provided. The system may include a controller coupled to a dynamic model of the plant to process a prediction of plant performance and determine a control strategy for the IGCC plant over a time horizon subject to plant constraints. The control strategy may include control functionality to meet a tracking objective and control functionality to meet an optimization objective. The control strategy may be configured to prioritize the tracking objective over the optimization objective based on a coordinate transformation, such as an orthogonal or quasi-orthogonal projection. A plurality of plant control knobs may be set in accordance with the control strategy to generate a sequence of coordinated multivariable control inputs to meet the tracking objective and the optimization objective subject to the prioritization resulting from the coordinate transformation.

  10. Linfonodo sentinela após mamoplastia de aumento pela via transaxilar: estudo prospectivo controlado por meio de linfocintilografia em 43 pacientes Sentinel lymph node detection after transaxillary augmentation mammoplasty: a prospective controlled study utilizing lymphoscintigraphy in 43 breasts

    Directory of Open Access Journals (Sweden)

    Heitor Naoki Sado

    2008-10-01

    Full Text Available OBJETIVO: Verificar se a mamoplastia de aumento pela via transaxilar apresenta potencial de prejudicar a identificação futura do linfonodo sentinela. MATERIAIS E MÉTODOS: Estudo prospectivo controlado em que foram selecionadas 22 pacientes divididas em grupo pós-mamoplastia e grupo controle, totalizando 43 mamas (22 no grupo pós-mamoplastia e 21 no grupo controle avaliadas por meio de linfocintilografia imediatamente após injeções periareolares de fitato-99mTc. Os testes estatísticos consideraram como diferenças significativas valores de p OBJECTIVE: To evaluate the potential influence of transaxillary augmentation mammoplasty on future detection of sentinel lymph node. MATERIALS AND METHODS: Prospective controlled study where 22 patients were selected and divided into two groups (post-mammoplasty and control corresponding to 43 breasts (22 in the post-mammoplasty group and 21 in the control group evaluated by lymphoscintigraphy immediately after periareolar 99mTc-phytate injections. In the statistical analysis, p values < 0.05 were considered as significant. RESULTS: All the breasts in the post-mammoplasty group presented lymphatic drainage to the axillary chain, with no difference as compared with the control group (p = 0.488. The average number of hot lymph nodes was 1.27 ± 0.46 in the post-mammoplasty group, and 1.33 ± 0.58 in the control group (p = 0.895. The mean time required to visualize the first lymph node was 3.14 ± 4.42 minutes in the post-mammoplasty group, and 5.48 ± 5.06 minutes in the control group (p = 0.136. CONCLUSION: Transaxillary augmentation mammoplasty did not affect the future detection of sentinel lymph node.

  11. BACK TO BACK VOLTAGE SOURCE INVERTER FOR CONTROL OF SELF EXCITED INDUCTION GENERATOR

    Directory of Open Access Journals (Sweden)

    Ainur Rachmad Hidayat

    2017-01-01

    Full Text Available Wind is one of the most develop renewable energy to help human meet the electricity needs as availability is abundant. Instrument which can be used to convert wind energy into electrical energy is an induction generator. In this final project will discuss about the operation of the wind turbine with induction generator controlled using back to back voltage source inverter with grid connected system low voltage 380 V. Switching of back to back voltage source inverter was designed in average model.In back to back voltage source inverter, there are two converters that are machine side converter and grid side converter. Machine side converter has function to regulate the voltage and frequency of generator and turbine speed in order to the wind turbine can generate maximum power at any wind speed with method volt / hetrz constant control. Grid side converter has function to adjust the DC voltage keep be contant by synchronizing the phase angle between the converter output and grid using current controlled voltage source inverter method.The simulation results showed that wind turbine always generated the maximum power at any wind speed. Voltage and frequency of Generator is stable and directly proportional to the wind speed and the dc link voltage is always constant so the power flow can bidirectional. Therefore, back-to-back voltage source inverter is suitable for controlling wind turbine using an induction generator.  

  12. Autonomous Decentralized Control of Supply and Demand by Inverter Based Distributed Generations in Isolated Microgrid

    Science.gov (United States)

    Shiki, Akira; Yokoyama, Akihiko; Baba, Jyunpei; Takano, Tomihiro; Gouda, Takahiro; Izui, Yoshio

    Recently, because of the environmental burden mitigation, energy conservations, energy security, and cost reductions, distributed generations are attracting our strong attention. These distributed generations (DGs) have been already installed to the distribution system, and much more DGs will be expected to be connected in the future. On the other hand, a new concept called “Microgrid” which is a small power supply network consisting of only DGs was proposed and some prototype projects are ongoing in Japan. The purpose of this paper is to develop the three-phase instantaneous valued digital simulator of microgrid consisting of a lot of inverter based DGs and to develop a supply and demand control method in isolated microgrid. First, microgrid is modeled using MATLAB/SIMULINK. We develop models of three-phase instantaneous valued inverter type CVCF generator, PQ specified generator, PV specified generator, PQ specified load as storage battery, photovoltaic generation, fuel cell and inverter load respectively. Then we propose an autonomous decentralized control method of supply and demand in isolated microgrid where storage batteries, fuel cells, photovoltaic generations and loads are connected. It is proposed here that the system frequency is used as a means to control DG output. By changing the frequency of the storage battery due to unbalance of supply and demand, all inverter based DGs detect the frequency fluctuation and change their own outputs. Finally, a new frequency control method in autonomous decentralized control of supply and demand is proposed. Though the frequency is used to transmit the information on the supply and demand unbalance to DGs, after the frequency plays the role, the frequency finally has to return to a standard value. To return the frequency to the standard value, the characteristic curve of the fuel cell is shifted in parallel. This control is carried out corresponding to the fluctuation of the load. The simulation shows that the

  13. Application of Load Compensation in Voltage Controllers of Large Generators in the Polish Power Grid

    Directory of Open Access Journals (Sweden)

    Bogdan Sobczak

    2014-03-01

    Full Text Available The Automatic Voltage Regulator normally controls the generator stator terminal voltage. Load compensation is used to control the voltage which is representative of the voltage at a point either within or external to the generator. In the Polish Power Grid (PPG compensation is ready to use in every AVR of a large generator, but it is utilized only in the case of generators operating at the same medium voltage buses. It is similar as in most European Power Grids. The compensator regulating the voltage at a point beyond the machine terminals has significant advantages in comparison to the slower secondary Voltage and Reactive Power Control System (ARNE1. The compensation stiffens the EHV grid, which leads to improved voltage quality in the distribution grid. This effect may be particularly important in the context of the dynamic development of wind and solar energy.

  14. Kaman 40 kW wind turbine generator - control system dynamics

    Science.gov (United States)

    Perley, R.

    1981-01-01

    The generator design incorporates an induction generator for application where a utility line is present and a synchronous generator for standalone applications. A combination of feed forward and feedback control is used to achieve synchronous speed prior to connecting the generator to the load, and to control the power level once the generator is connected. The dynamics of the drive train affect several aspects of the system operation. These were analyzed to arrive at the required shaft stiffness. The rotor parameters that affect the stability of the feedback control loop vary considerably over the wind speed range encountered. Therefore, the controller gain was made a function of wind speed in order to maintain consistent operation over the whole wind speed range. The velocity requirement for the pitch control mechanism is related to the nature of the wind gusts to be encountered, the dynamics of the system, and the acceptable power fluctuations and generator dropout rate. A model was developed that allows the probable dropout rate to be determined from a statistical model of wind gusts and the various system parameters, including the acceptable power fluctuation.

  15. Effects of augmented reality-based Otago exercise on balance, gait, and physical factors in elderly women to prevent falls: a randomized controlled trial.

    Science.gov (United States)

    Lee, Jin; Yoo, Ha-Na; Lee, Byoung-Hee

    2017-09-01

    [Purpose] To determine the effect of augmented reality (AR)-based otago exercise on muscle strength, balance, and physical factors in falls of elderly women. [Subjects and Methods] Thirty subjects were randomly assigned to AR group (AR, n=10), yoga group (yoga, n=10), and self-exercise group (self, n=10). For 12 weeks, these groups were given lessons related to AR-based otago exercise including strengthening, balance training, or yoga three times a week (60 minutes each time) and self-exercise using elastic band exercise program. [Results] Knee flexion and ankle dorsiflexion strength were significantly improved in all three groups (AR, yoga, and self-exercise groups). Regarding balance, eye open center of pressure-x (EO CoP-x) was significantly decreased in AR group and yoga group. However, eye close CoP-x, eye open standard deviation-x (EO SD-x), and eye open height of ellipse (EO HoE) were only significantly decreased in AR group. AR group also showed meaningfully improved results in morse fall scale. [Conclusion] Augmented reality-based otago exercise can improve muscle strength, balance, and physical factors in elderly women to prevent falls.

  16. Specific phobias in youth: a randomized controlled trial comparing one-session treatment to a parent-augmented one-session treatment.

    Science.gov (United States)

    Ollendick, Thomas H; Halldorsdottir, Thorhildur; Fraire, Maria G; Austin, Kristin E; Noguchi, Ryoichi J P; Lewis, Krystal M; Jarrett, Matthew A; Cunningham, Natoshia R; Canavera, Kristin; Allen, Kristy B; Whitmore, Maria J

    2015-03-01

    Examine the efficacy of a parent-augmented One-Session Treatment (A-OST) in treating specific phobias (SP) in youth by comparing this novel treatment to child-focused OST, a well-established treatment. A total of 97 youth (ages 6-15, 51.5% female, 84.5% White) who fulfilled diagnostic criteria for SP were randomized to either A-OST or OST. SPs were assessed with semistructured diagnostic interviews, clinician improvement ratings, and parent and child improvement ratings. In addition, measures of treatment satisfaction and parental self-efficacy were obtained. Blind assessments were completed pretreatment, posttreatment, and 1month and 6months following treatment. Analyses were undertaken using mixed models. In addition, gender, age, internalizing/externalizing problems, parent overprotection, and parent anxiety were examined as potential predictors and moderators of treatment outcome. Both treatment conditions produced similar outcomes with approximately 50% of youth in both treatments diagnosis free and judged to be much or very much improved at posttreatment and 1-month follow-up. At 6-month follow-up, however, the treatments diverged with OST resulting in marginally superior outcomes to A-OST, contrary to predictions. Only age of child predicted treatment outcome across the two treatments (older children did better); unexpectedly, none of the variables moderated treatment outcomes. Parent augmentation of OST produced no appreciable gains in treatment outcomes. Directions for future research are highlighted. Copyright © 2014. Published by Elsevier Ltd.

  17. Spiraling out of control: Stress generation and subsequent rumination mediate the link between poorer cognitive control and internalizing psychopathology

    Science.gov (United States)

    Snyder, Hannah R.; Hankin, Benjamin L.

    2016-01-01

    Poor cognitive control is associated with nearly every mental disorder and has been proposed as a transdiagnostic risk factor for psychopathology, including depression and anxiety. What specific mechanisms might cause individuals with poor cognitive control to experience higher levels of psychopathology? The current research tests a new process model linking poor cognitive control to depression and anxiety symptoms via increased dependent stress (i.e., self-generated stressors) and subsequent rumination. This model was supported across two studies in youth during the key period for emergence of internalizing psychopathology. Study 1 provides longitudinal evidence for prospective prediction of change in symptoms. Study 2 confirms this model using well-established executive function tasks in a cross-sectional study. These finding have potential implications for understanding why cognitive control impairments may be broadly associated with psychopathology, and suggest that interventions to prevent stress generation might be effective in preventing negative consequences of poor cognitive control. PMID:27840778

  18. Voltage Control Support and Coordination between Renewable Generation Plants in MV Distribution Systems

    DEFF Research Database (Denmark)

    Petersen, Lennart; Iov, Florin; D. Hansen, Anca

    2016-01-01

    This paper focusses on voltage control support and coordination between renewable generation plants in medium voltage distribution systems. An exemplary benchmark grid in Denmark, including a number of flexible ReGen plants providing voltage control functionality, is used as a base case. First...

  19. Self-tuning fuzzy logic control of a switched reluctance generator for wind energy applications

    DEFF Research Database (Denmark)

    Park, Kiwoo; Chen, Zhe

    2012-01-01

    This paper presents a new self-tuning fuzzy logic control (FLC) based speed controller of a switched reluctance generator (SRG) for wind power applications. Due to its doubly salient structure and magnetic saturation, the SRG possesses an inherent characteristic of strong nonlinearity. In addition...

  20. Three-Phase Grid-Connected of Photovoltaic Generator Using Nonlinear Control

    DEFF Research Database (Denmark)

    Yahya, A.; El Fadil, H.; Guerrero, Josep M.

    2014-01-01

    This paper proposes a nonlinear control methodology for three phase grid connected of PV generator. It consists of a PV arrays; a voltage source inverter, a grid filter and an electric grid. The controller objectives are threefold: i) ensuring the Maximum power point tracking (MPPT) in the side o...

  1. Differential evolution algorithm based automatic generation control for interconnected power systems with

    Directory of Open Access Journals (Sweden)

    Banaja Mohanty

    2014-09-01

    Full Text Available This paper presents the design and performance analysis of Differential Evolution (DE algorithm based Proportional–Integral (PI and Proportional–Integral–Derivative (PID controllers for Automatic Generation Control (AGC of an interconnected power system. Initially, a two area thermal system with governor dead-band nonlinearity is considered for the design and analysis purpose. In the proposed approach, the design problem is formulated as an optimization problem control and DE is employed to search for optimal controller parameters. Three different objective functions are used for the design purpose. The superiority of the proposed approach has been shown by comparing the results with a recently published Craziness based Particle Swarm Optimization (CPSO technique for the same interconnected power system. It is noticed that, the dynamic performance of DE optimized PI controller is better than CPSO optimized PI controllers. Additionally, controller parameters are tuned at different loading conditions so that an adaptive gain scheduling control strategy can be employed. The study is further extended to a more realistic network of two-area six unit system with different power generating units such as thermal, hydro, wind and diesel generating units considering boiler dynamics for thermal plants, Generation Rate Constraint (GRC and Governor Dead Band (GDB non-linearity.

  2. Robust Current Control of Doubly Fed Wind Turbine Generator under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Wang, Yun; Gong, Wenming; Wu, Qiuwei

    2014-01-01

    This paper presents the design of a H ∞ current controller for doubly fed induction generators (DFIGs) in order to maintain stable operation under unbalanced voltage conditions. The H ∞ current controller has a multi-input and multi-output (MIMO) structure and is designed using the loop shaping...

  3. Generation of American elm trees with tolerance to Dutch elm disease through controlled crosses and selection

    Science.gov (United States)

    James M. Slavicek; Kathleen S. Knight

    2012-01-01

    The goal of our research and development efforts is to generate new and/or improved selections of the American elm (Ulmus americana L.) with tolerance/resistance to Dutch elm disease (DED). The approaches we are taking for this effort include: 1) controlled breeding using known DED -tolerant selections, 2) controlled breeding using DED-tolerant...

  4. Thrust Augmentation with Mixer/Ejector Systems

    Science.gov (United States)

    Presz, Walter M., Jr.; Reynolds, Gary; Hunter, Craig

    2002-01-01

    Older commercial aircraft often exceed FAA (Federal Aviation Administration) sideline noise regulations. The major problem is the jet noise associated with the high exhaust velocities of the low bypass ratio engines on such aircraft. Mixer/ejector exhaust systems can provide a simple means of reducing the jet noise on these aircraft by mixing cool ambient air with the high velocity engine gases before they are exhausted to ambient. This paper presents new information on thrust performance predictions, and thrust augmentation capabilities of mixer/ejectors. Results are presented from the recent development program of the patented Alternating Lobe Mixer Ejector Concept (ALMEC) suppressor system for the Gulfstream GII, GIIB and GIII aircraft. Mixer/ejector performance procedures are presented which include classical control volume analyses, compound compressible flow theory, lobed nozzle loss correlations and state of the art computational fluid dynamic predictions. The mixer/ejector thrust predictions are compared to subscale wind tunnel test model data and actual aircraft flight test measurements. The results demonstrate that a properly designed mixer/ejector noise suppressor can increase effective engine bypass ratio and generate large thrust gains at takeoff conditions with little or no thrust loss at cruise conditions. The cruise performance obtained for such noise suppressor systems is shown to be a strong function of installation effects on the aircraft.

  5. A Current Sensorless MPPT Control Method for a Stand-Alone-Type PV Generation System

    Science.gov (United States)

    Itako, Kazutaka; Mori, Takeaki

    In this paper, a current sensorless MPPT control method for a stand-alone-type PV generation system is proposed. This control method offers advantages of the simplified hardware configuration and the low cost, by using only one sensor to measure the PV output voltage. In the application to stand-alone-type with a battery load, the experimental results show that the estimated values of PV output current are accurate, and the use of the proposed MPPT control increases the PV generated energy by 16.3% compared to the conventional system. Furthermore, it is clarified that the proposed method has extremely high UUF (Useful utilization factor) of 98.7%.

  6. Research on the control strategy of distributed energy resources inverter based on improved virtual synchronous generator.

    Science.gov (United States)

    Gao, Changwei; Liu, Xiaoming; Chen, Hai

    2017-08-22

    This paper focus on the power fluctuations of the virtual synchronous generator(VSG) during the transition process. An improved virtual synchronous generator(IVSG) control strategy based on feed-forward compensation is proposed. Adjustable parameter of the compensation section can be modified to achieve the goal of reducing the order of the system. It can effectively suppress the power fluctuations of the VSG in transient process. To verify the effectiveness of the proposed control strategy for distributed energy resources inverter, the simulation model is set up in MATLAB/SIMULINK platform and physical experiment platform is established. Simulation and experiment results demonstrate the effectiveness of the proposed IVSG control strategy.

  7. Randomized, controlled clinical trial to evaluate a xenogeneic collagen matrix as an alternative to free gingival grafting for oral soft tissue augmentation.

    Science.gov (United States)

    McGuire, Michael K; Scheyer, E Todd

    2014-10-01

    The standard of care for increasing keratinized tissue (KT) and vestibular area is an autogenous free gingival graft (FGG) and vestibuloplasty; however, there is morbidity associated with the harvest of autogenous tissue, and supply is limited. The purpose of this study is to determine if a xenogeneic collagen matrix (CM) might be as effective as FGG. This study is a single-masked, randomized, controlled, split-mouth study of 30 patients with insufficient zones of KT (FGG) therapy. The primary efficacy endpoint was change in KT width (∆KT) from surgery to 6 months post-surgery. Secondary endpoints included traditional periodontal measures, such as clinical attachment level, recession, and bleeding on probing. Patient-reported pain, discomfort, and esthetic satisfaction were also recorded. Biopsies were obtained at 6 months. Surgery and postoperative sequelae were uneventful, with normal healing observed at both test and control sites. The primary outcome, ∆KT width at 6 months, did not establish non-inferiority of CM compared to FGG (P = 0.9992), with the FGG sites averaging 1.5 mm more KT width than CM sites. However, the amount of new KT generated for both therapies averaged ≥2 mm. Secondary outcomes were not significantly different between test and control sites. All site biopsies appeared as normal mucoperiosteum with keratinized epithelium. CM sites achieved better texture and color matches, and more than two-thirds of patients preferred the appearance of their CM sites. With the proviso of sufficient KT (≈2 mm in width) and study goals of lower morbidity, unlimited supply, and patient satisfaction, CM appears to be a suitable substitute for FGG in vestibuloplasty procedures designed to increase KT around teeth.

  8. Controllable pneumatic generator based on the catalytic decomposition of hydrogen peroxide.

    Science.gov (United States)

    Kim, Kyung-Rok; Kim, Kyung-Soo; Kim, Soohyun

    2014-07-01

    This paper presents a novel compact and controllable pneumatic generator that uses hydrogen peroxide decomposition. A fuel micro-injector using a piston-pump mechanism is devised and tested to control the chemical decomposition rate. By controlling the injection rate, the feedback controller maintains the pressure of the gas reservoir at a desired pressure level. Thermodynamic analysis and experiments are performed to demonstrate the feasibility of the proposed pneumatic generator. Using a prototype of the pneumatic generator, it takes 6 s to reach 3.5 bars with a reservoir volume of 200 ml at the room temperature, which is sufficiently rapid and effective to maintain the repetitive lifting of a 1 kg mass.

  9. nARratives of augmented worlds

    OpenAIRE

    Shilkrot, Roy; Montfort, Nick; Maes, Patricia

    2014-01-01

    This paper presents an examination of augmented reality (AR) as a rising form of interactive narrative that combines computer-generated elements with reality, fictional with non-fictional objects, in the same immersive experience. Based on contemporary theory in narratology, we propose to view this blending of reality worlds as a metalepsis, a transgression of reality and fiction boundaries, and argue that authors could benefit from using existing conventions of narration to emphasize the tra...

  10. Cortical Modulation of Motor Control Biofeedback among the Elderly with High Fall Risk during a Posture Perturbation Task with Augmented Reality.

    Science.gov (United States)

    Chang, Chun-Ju; Yang, Tsui-Fen; Yang, Sai-Wei; Chern, Jen-Suh

    2016-01-01

    The cerebral cortex provides sensorimotor integration and coordination during motor control of daily functional activities. Power spectrum density based on electroencephalography (EEG) has been employed as an approach that allows an investigation of the spatial-temporal characteristics of neuromuscular modulation; however, the biofeedback mechanism associated with cortical activation during motor control remains unclear among elderly individuals. Thirty one community-dwelling elderly participants were divided into low fall-risk potential (LF) and high fall-risk potential (HF) groups based upon the results obtained from a receiver operating characteristic analysis of the ellipse area of the center of pressure. Electroencephalography (EEG) was performed while the participants stood on a 6-degree-of-freedom Stewart platform, which generated continuous perturbations and done either with or without the virtual reality scene. The present study showed that when there was visual stimulation and poor somatosensory coordination, a higher level of cortical response was activated in order to keep postural balance. The elderly participants in the LF group demonstrated a significant and strong correlation between postural-related cortical regions; however, the elderly individuals in the HF group did not show such a relationship. Moreover, we were able to clarify the roles of various brainwave bands functioning in motor control. Specifically, the gamma and beta bands in the parietal-occipital region facilitate the high-level cortical modulation and sensorimotor integration, whereas the theta band in the frontal-central region is responsible for mediating error detection during perceptual motor tasks. Finally, the alpha band is associated with processing visual challenges in the occipital lobe.With a variety of motor control demands, increment in brainwave band coordination is required to maintain postural stability. These investigations shed light on the cortical modulation of

  11. Cortical modulation of motor control biofeedback among the elderly with high fall risk during a posture perturbation task with augmented reality

    Directory of Open Access Journals (Sweden)

    Chun-Ju eCHANG

    2016-04-01

    Full Text Available The cerebral cortex provides sensorimotor integration and coordination during motor control of daily functional activities. Power spectrum density (PSD based on electroencephalography (EEG has been employed as an approach that allows an investigation of the spatial-temporal characteristics of neuromuscular modulation; however, the biofeedback mechanism associated with cortical activation during motor control remains unclear among elderly individuals. Thirty one community-dwelling elderly participants were divided into low fall-risk potential (LF and high fall-risk potential (HF groups based upon the results obtained from a receiver operating characteristic analysis of the ellipse area of the center of pressure. EEG was performed while the participants stood on a 6-degree-of-freedom Stewart platform, which generated continuous perturbations and done either with or without the virtual reality scene. The present study showed that when there was visual stimulation and poor somatosensory coordination, a higher level of cortical response was activated in order to keep postural balance. The elderly participants in the LF group demonstrated a significant and strong correlation between postural-related cortical regions; however, the elderly individuals in the HF group did not show such a relationship. Moreover, we were able to clarify the roles of various brainwave bands functioning in motor control. Specifically, the gamma and beta bands in the parietal–occipital region facilitate the high-level cortical modulation and sensorimotor integration, whereas the theta band in the frontal–central region is responsible for mediating error detection during perceptual motor tasks. Finally, the alpha band is associated with processing visual challenges in the occipital lobe. With a variety of motor control demands, increment in brainwave band coordination is required to maintain postural stability. These investigations shed light on the cortical modulation of

  12. On designing a control system for a new generation of accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Schaller, S.C.; Schultz, D.E.

    1987-01-01

    A well-conceived plan of attack is essential to the task of designing a control system for a large accelerator. Several aspects of such a plan have been investigated during recent work at LAMPF on design strategies for an Advanced Hadron Facility control system. Aspects discussed in this paper include: identification of requirements, creation and enforcement of standards, interaction with users, consideration of commercial controls products, integration with existing control systems, planning for continual change, and establishment of design reviews. We emphasize the need for the controls group to acquire and integrate accelerator design information from the start of the design process. We suggest that a controls design for a new generation of accelerators be done with a new generation of software tools. 12 refs.

  13. DCS (Digital Control System) application of three generations; Aplicacao de um SDCD (Sistemas Digitais de Controle Distribuido) de tres geracoes

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Celso Roberto Molinaro [PETROBRAS S.A., Sao Jose dos Campos, SP (Brazil). Refinaria Henrique Lage (REVAP)

    2004-07-01

    Digital Control System are three generations of hardware and software platforms in process automation , but DCS is using the same functions and presents the reliability and availability . The challenge in automation has to maintain the old and the newest system operating and integrated perhaps the different times of platforms to guarantee the actual investments and in the future. A new generation of DCS using field equipment to control or the actual architecture with a lot of new information are coming with the technologies. (author)

  14. Radiative Augmented Combustion.

    Science.gov (United States)

    1985-08-12

    86-0085 In 00I to RADIATIVE AUGMENTED COMBUSTION MOSHE LAVID M.L. ENERGIA , INC. P.O. BOX 1468 1 PRINCETON, NEW JERSEY 08542 AUGUST 1985 *.. plo...Combustion conducted at M.L. ENERGIA . It is funded by the Air Force Office of Scientific Research under Contract No. F49620-83-C-0133, with Dr. J.M...reported. It covers the second year of the contract, from July 15, 1984 through July 14, 1985. The work was performed at ENERGIA , Princeton, New Jersey

  15. Damping-tunable energy-harvesting vehicle damper with multiple controlled generators: Design, modeling and experiments

    Science.gov (United States)

    Xie, Longhan; Li, Jiehong; Li, Xiaodong; Huang, Ledeng; Cai, Siqi

    2018-01-01

    Hydraulic dampers are used to decrease the vibration of a vehicle, where vibration energy is dissipated as heat. In addition to resulting in energy waste, the damping coefficient in hydraulic dampers cannot be changed during operation. In this paper, an energy-harvesting vehicle damper was proposed to replace traditional hydraulic dampers. The goal is not only to recover kinetic energy from suspension vibration but also to change the damping coefficient during operation according to road conditions. The energy-harvesting damper consists of multiple generators that are independently controlled by switches. One of these generators connects to a tunable resistor for fine tuning the damping coefficient, while the other generators are connected to a control and rectifying circuit, each of which both regenerates electricity and provides a constant damping coefficient. A mathematical model was built to investigate the performance of the energy-harvesting damper. By controlling the number of switched-on generators and adjusting the value of the external tunable resistor, the damping can be fine tuned according to the requirement. In addition to the capability of damping tuning, the multiple controlled generators can output a significant amount of electricity. A prototype was built to test the energy-harvesting damper design. Experiments on an MTS testing system were conducted, with results that validated the theoretical analysis. Experiments show that changing the number of switched-on generators can obviously tune the damping coefficient of the damper and simultaneously produce considerable electricity.

  16. Single i.v. ketamine augmentation of newly initiated escitalopram for major depression: results from a randomized, placebo-controlled 4-week study.

    Science.gov (United States)

    Hu, Y-D; Xiang, Y-T; Fang, J-X; Zu, S; Sha, S; Shi, H; Ungvari, G S; Correll, C U; Chiu, H F K; Xue, Y; Tian, T-F; Wu, A-S; Ma, X; Wang, G

    2016-02-01

    While oral antidepressants reach efficacy after weeks, single-dose intravenous (i.v.) ketamine has rapid, yet time-limited antidepressant effects. We aimed to determine the efficacy and safety of single-dose i.v. ketamine augmentation of escitalopram in major depressive disorder (MDD). Thirty outpatients with severe MDD (17-item Hamilton Rating Scale for Depression total score ⩾ 24) were randomized to 4 weeks double-blind treatment with escitalopram 10 mg/day+single-dose i.v. ketamine (0.5 mg/kg over 40 min) or escitalopram 10 mg/day + placebo (0.9% i.v. saline). Depressive symptoms were measured using the Montgomery-Asberg Depression Rating Scale (MADRS) and the Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR). Suicidal ideation was evaluated with the QIDS-SR item 12. Adverse psychopathological effects were measured with the Brief Psychiatric Rating Scale (BPRS)-positive symptoms, Young Mania Rating Scale (YMRS) and Clinician Administered Dissociative States Scale (CADSS). Patients were assessed at baseline, 1, 2, 4, 24 and 72 h and 7, 14, 21 and 28 days. Time to response (⩾ 50% MADRS score reduction) was the primary outcome. By 4 weeks, more escitalopram + ketamine-treated than escitalopram + placebo-treated patients responded (92.3% v. 57.1%, p = 0.04) and remitted (76.9% v. 14.3%, p = 0.001), with significantly shorter time to response [hazard ratio (HR) 0.04, 95% confidence interval (CI) 0.01-0.22, p p = 0.01). Compared to escitalopram + placebo, escitalopram + ketamine was associated with significantly lower MADRS scores from 2 h to 2 weeks [(peak = 3 days-2 weeks; effect size (ES) = 1.08-1.18)], QIDS-SR scores from 2 h to 2 weeks (maximum ES = 1.27), and QIDS-SR suicidality from 2 to 72 h (maximum ES = 2.24). Only YMRS scores increased significantly with ketamine augmentation (1 and 2 h), without significant BPRS or CADSS elevation. Single-dose i.v. ketamine augmentation of escitalopram was safe and effective in severe MDD, holding

  17. MODELLING AND FUZZY LOGIC CONTROL OF PEM FUEL CELL SYSTEM POWER GENERATION FOR RESIDENTIAL APPLICATION

    OpenAIRE

    MAMMAR, Khaled; Chaker, Abdelkader

    2010-01-01

    This paper presents a dynamic model of Fuel cell system for residential power generation. The models proposedinclude a fuel cell stack model, reformer model and DC/AC inverter model. More then an analytical details ofhow active and reactive power output of a proton-exchange-membrane (PEM) fuel cell system is controlled.Furthermore a fuzzy logic (FLC) controller is used to control active power of PEM fuel cell system. Thecontroller modifies the hydrogen flow feedback from the terminal load. Si...

  18. Augmented reality for improved safety

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

    Sometimes, CERN experts have to operate in low visibility conditions or in the presence of possible hazards. Minimising the duration of the operation and reducing the risk of errors is therefore crucial to ensuring the safety of personnel. The EDUSAFE project integrates different technologies to create a wearable personnel safety system based on augmented reality.    The EDUSAFE integrated safety system uses a camera mounted on the helmet to monitor the working area.  In its everyday operation of machines and facilities, CERN adopts a whole set of measures and safety equipment to ensure the safety of its personnel, including personal wearable safety devices and access control systems. However, sometimes, scheduled and emergency maintenance work needs to be done in zones with potential cryogenic hazards, in the presence of radioactive equipment or simply in demanding conditions where visibility is low and moving around is difficult. The EDUSAFE Marie Curie Innovative&...

  19. Transient stability and control of wind turbine generation based on Hamiltonian surface shaping and power flow control

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, David G.; Robinett, Rush D. III [Sandia National Laboratories, Albuquerque, NM (United States). Energy, Resources and Systems Analysis Center

    2010-07-01

    The swing equations for renewable generators connected to the grid are developed and a simple wind turbine with UPFC is used as an example. The swing equations for renewable generator are formulated as a natural Hamiltonian system with externally applied non-conservative forces. A two-step process referred to as Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is used to analyze and design feedback controllers for the renewable generators system. This formulation extends previous results on the analytical verification of the Potential Energy Boundary Surface (PEBS) method to nonlinear control analysis and design and justifies the decomposition of the system into conservative and nonconservative systems to enable a two-step, serial analysis and design procedure. This paper presents the analysis and numerical simulation results for a nonlinear control design example that includes the One-Machine Infinite Bus (OMIB) system with a Unified Power Flow Control (UPEC) and applied to a simplified wind turbine generator. The needed power and energy storage/charging responses are also determined. (orig.)

  20. Enhanced Control for a Direct-driven Permanent Synchronous Generator Wind-power Generation System with Flywheel Energy Storage Unit Under Unbalanced Grid Fault

    DEFF Research Database (Denmark)

    Yao, Jun; Zhou, Te; Hu, Weihao

    2015-01-01

    This article presents an enhanced control strategy for a direct-driven permanent synchronous generator based wind-power generation system with a flywheel energy storage unit. The behaviors of the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit under......, the proposed coordinated control strategy for the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit has been validated by the simulation results of a 1-MW direct-driven permanent magnet synchronous generator wind power generation system with a flywheel energy......, the DC-link voltage oscillations can be effectively suppressed during the unbalanced grid fault by controlling the flywheel energy storage unit. Furthermore, a proportional–integral-resonant controller is designed for the flywheel motor to eliminate the oscillations in the DC-link voltage. Finally...

  1. Overall control strategy of variable speed doubly-fed induction generator wind turbine

    DEFF Research Database (Denmark)

    Hansen, A. D.; Soerensen, P.; Iov, Florin

    2004-01-01

    turbine. The present control method is designed for normal continuous operations. The strongest feature of the implemented control method is that it allows the turbine to operate with the optimum power efficiency over a wider range of wind speeds. The variable speed/variable pitch wind turbine with doubly......The variable speed doubly-fed induction generator wind turbine is today the most widely used concept. The paper presents an overall control system of the variable speed DFIG wind turbine, with focus on the control strategies and algorithms applied at each hierarchical control level of the wind...

  2. Advanced control of direct-driven PMSG generator in wind turbine system

    Directory of Open Access Journals (Sweden)

    Gajewski Piotr

    2016-12-01

    Full Text Available The paper presents the advanced control system of the wind energy conversion with a variable speed wind turbine. The considered system consists of a wind turbine with the permanent magnet synchronous generator (PMSG, machine side converter (MSC, grid side converter (GSC and control circuits. The mathematical models of a wind turbine system, the PMSG generator and converters have been described. The control algorithms of the converter systems based on the methods of vector control have been applied. In the advanced control system of the machine side converter the optimal MPPT control method has been used. Additionally the pitch control scheme is included in order to achieve the limitation of maximum power and to prevent mechanical damage of the wind turbine. In the control system of the grid side converter the control of active and reactive power has been applied with the application of Voltage Oriented Control (VOC. The performance of the considered wind energy system has been studied by digital simulation. The results of simulation studies confirmed the good effectiveness of the considered wind turbine system and very good performance of the proposed methods of vector control and control systems.

  3. Exploring the optimum approach to the use of CT densitometry in a randomised placebo-controlled study of augmentation therapy in alpha 1-antitrypsin deficiency

    DEFF Research Database (Denmark)

    Parr, David G; Dirksen, Asger; Piitulainen, Eeva

    2009-01-01

    BACKGROUND: Computed tomography (CT) lung densitometry has been demonstrated to be the most sensitive and specific outcome measure for the assessment of emphysema-modifying therapy, but the optimum densitometric index has yet to be determined and targeted sampling may be more sensitive than whole...... lung assessment. The EXAcerbations and CT scan as Lung Endpoints (EXACTLE) trial aimed to clarify the optimum approach to the use of CT densitometry data for the assessment of alpha 1-antitrypsin (AAT) augmentation therapy on the progression of emphysema in AAT deficiency (AATD). METHODS: Patients...... of emphysema in the apical, middle and basal regions of the lung by measurement with PD15 showed that this treatment effect was more evident when the basal third was sampled (1.722 g/L, p = 0.040). A comparison between different densitometric indices indicated that the influence of inspiratory variability...

  4. An augmented reality framework for optimization of computer assisted navigation in endovascular surgery.

    Science.gov (United States)

    Cheng, Irene; Shen, Rui; Moreau, Richard; Brizzi, Vicenzo; Rossol, Nathaniel; Basu, Anup

    2014-01-01

    Endovascular surgery is performed by placing a catheter through blood vessels. Due to the fragility of arteries and the difficulty in controlling a long elastic wire to reach the target region, training plays an extremely important role in helping a surgeon acquire the required complex skills. Virtual reality simulators and augmented reality systems have proven to be effective in minimally invasive surgical training. These systems, however, often employ pre-captured or computer-generated medical images. We have developed an augmented reality system for ultrasound-guided endovascular surgical training, where real ultrasound images captured during the procedure are registered with a pre-scanned phantom model to give the operator a realistic experience. Our goal is to extend the planning and training environment to deliver a system for computer assisted remote endovascular surgery where the navigation of a catheter can be controlled through a robotic device based on the guidance provided by an endovascular surgeon.

  5. Embedded system based on PWM control of hydrogen generator with SEPIC converter

    Science.gov (United States)

    Fall, Cheikh; Setiawan, Eko; Habibi, Muhammad Afnan; Hodaka, Ichijo

    2017-09-01

    The objective of this paper is to design and to produce a micro electrical plant system based on fuel cell for teaching material-embedded systems in technical vocational training center. Based on this, the student can experience generating hydrogen by fuel cells, controlling the rate of hydrogen generation by the duty ration of single-ended primary-inductor converter(SEPIC), drawing the curve rate of hydrogen to duty ratio, generating electrical power by using hydrogen, and calculating the fuel cell efficiency when it is used as electrical energy generator. This project is of great importance insofar as students will need to acquire several skills to be able to realize it such as continuous DC DC conversion and the scientific concept behind the converter, the regulation of systems with integral proportional controllers, the installation of photovoltaic cells, the use of high-tech sensors, microcontroller programming, object-oriented programming, mastery of the fuel cell syste

  6. AMI: Augmented Michelson Interferometer

    Science.gov (United States)

    Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

    2015-10-01

    Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

  7. Augmented Reality for Science Education

    DEFF Research Database (Denmark)

    Brandt, Harald; Nielsen, Birgitte Lund; Georgsen, Marianne

    Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student...... involvement. The AR-sci-project (Augmented Reality for SCIence education) addresses the issue of applying augmented reality in developing innovative science education and enhancing the quality of science teaching and learning....

  8. A control strategy for a distributed power generation microgrid application with voltage and current controlled source converter

    OpenAIRE

    Serban, E; Serban, H

    2010-01-01

    This paper presents a pseudodroop control structure integrated within a microgrid system through distributed power generation (DPG) modules capable to function in off-grid islanded, genset-connected, and grid-connected modes of operation. System efficiency has an important role in order to harvest the maximum available renewable energy from dc or ac sources while providing power backup capability. A control strategy is proposed in off-grid islanded mode method based on the microgrid line-freq...

  9. Modelling, Analysis, and Control Aspects of a Rotating Power Electronic Brushless Doubly-Fed Induction Generator

    OpenAIRE

    Malik, Naveed ur Rehman

    2015-01-01

    This thesis deals with the modeling, analysis and control of a novel brushlessgenerator for wind power application. The generator is named as rotatingpower electronic brushless doubly-fed induction machine/generator (RPEBDFIM/G). A great advantage of the RPE-BDFIG is that the slip power recoveryis realized in a brushless manner. This is achieved by introducing an additionalmachine termed as exciter together with the rotating power electronicconverters, which are mounted on the shaft of a DFIG...

  10. Voltage Stabilization Control of Wide-Speed-Range Permanent-Magnet Synchronous Generator Systems

    OpenAIRE

    Miao, Dongmin

    2016-01-01

    DC power systems have a constant DC-link voltage, as well as the advantages such as high stability, high efficiency, small size and light weight; therefore, they are widely used in stand-alone power systems, e.g. the power systems in aircrafts and automobiles, isolated wind power generation systems, etc. Permanent-Magnet Synchronous Generators (PMSGs) possess the advantages including high power density, high efficiency, and high control precision, and have obtained great attention and have be...

  11. Controllable Grid Interface for Testing Ancillary Service Controls and Fault Performance of Utility-Scale Wind Power Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; Koralewicz, Przemyslaw; Wallen, Robb; Muljadi, Eduard

    2017-02-01

    The rapid expansion of wind power has led many transmission system operators to demand modern wind power plants to comply with strict interconnection requirements. Such requirements involve various aspects of wind power plant operation, including fault ride-through and power quality performance as well as the provision of ancillary services to enhance grid reliability. During recent years, the National Renewable Energy Laboratory (NREL) of the U.S. Department of Energy has developed a new, groundbreaking testing apparatus and methodology to test and demonstrate many existing and future advanced controls for wind generation (and other renewable generation technologies) on the multimegawatt scale and medium-voltage levels. This paper describes the capabilities and control features of NREL's 7-MVA power electronic grid simulator (also called a controllable grid interface, or CGI) that enables testing many active and reactive power control features of modern wind turbine generators -- including inertial response, primary and secondary frequency responses, and voltage regulation -- under a controlled, medium-voltage grid environment. In particular, this paper focuses on the specifics of testing the balanced and unbalanced fault ride-through characteristics of wind turbine generators under simulated strong and weak medium-voltage grid conditions. In addition, this paper provides insights on the power hardware-in-the-loop feature implemented in the CGI to emulate (in real time) the conditions that might exist in various types of electric power systems under normal operations and/or contingency scenarios. Using actual test examples and simulation results, this paper describes the value of CGI as an ultimate modeling validation tool for all types of 'grid-friendly' controls by wind generation.

  12. Visualization of flow separation and control by vortex generators on an single flap in landing configuration

    Directory of Open Access Journals (Sweden)

    Matějka Milan

    2012-04-01

    Full Text Available This paper focuses on a suppression of the flow separation, which occurs on a deflected flap, by means of vortex generators (VG's. An airfoil NACA 63A421 with a simple flap and vane-type vortex generators were used. The investigation was carried out by using experimental and numerical methods. The data from the numerical simulation of the flapped airfoil without VG's control were used for the vortex generator design. Two sizes, two different shapes and various spacing of the vortex generators were tested. The flow past the airfoil was visualized through three methods, namely tuft filaments technique, oil and thermo camera visualization. The experiments were performed in closed circuit wind tunnels with closed and open test sections. The lift curves for both cases without and with vortex generators were acquired for a lift coefficient improvement determination. The improvement was achieved for several cases by means all of the applied methods.

  13. Fuzzy logic control of self excited doubly-fed induction generator

    Energy Technology Data Exchange (ETDEWEB)

    Radaideh, S.M.; Alwash, S.R.; Albatran, S.A. [Jordan Univ. of Science and Technology, Irbid (Jordan)

    2010-03-09

    A doubly-fed induction generator (DFIG) is the preferred solution for limited variable speed systems, particularly in wind energy systems. This paper considered DFIG for use with flywheel energy systems, stand alone diesel systems, pumped storage power plants, small hydro energy systems, and for wind turbines. Three fuzzy logic controllers which were used to enhance the performance of the self excited doubly-fed induction generator (SEDFIG) were presented along with a mathematical model of SEDFIG. The study considered the terminal voltage; the generated power; and the DC voltage. The study considered 3 fuzzy logic controllers, notably a fuzzy PI controller of the terminal voltage, a fuzzy PD controller of the generated power and a fuzzy PD controller of the DC voltage with integral controller as feedback. A static var compensator was used as a reactive power source which regulated the terminal voltage. According to simulation results, the SEDFIG system was stable and could restore to its normal operation following an electrical fault. 17 refs., 3 tabs., 13 figs., 1 appendix.

  14. Augmented reality in medical education?

    National Research Council Canada - National Science Library

    Kamphuis, Carolien; Barsom, Esther; Schijven, Marlies; Christoph, Noor

    2014-01-01

    .... Educational technology and more specifically augmented reality (AR) has the potential to offer a highly realistic situated learning experience supportive of complex medical learning and transfer...

  15. Modified Neural Network for Dynamic Control and Operation of a Hybrid Generation Systems

    Directory of Open Access Journals (Sweden)

    Cong-Hui Huang

    2014-12-01

    Full Text Available This paper presents modified neural network for dynamic control and operation of a hybrid generation systems. PV and wind power are the primary power sources of the system to take full advantages of renewable energy, and the diesel-engine is used as a backup system. The simulation model of the hybrid system was developed using MATLAB Simulink. To achieve a fast and stable response for the real power control, the intelligent controller consists of a Radial Basis Function Network (RBFN and an modified Elman Neural Network (ENN for maximum power point tracking (MPPT. The pitch angle of wind turbine is controlled by ENN, and the PV system uses RBFN, where the output signal is used to control the DC I DC boost converters to achieve the MPPT. And the results show the hybrid generation system can effectively extract the maximum power from the PV and wind energy sources.

  16. Active Power Optimal Control of Wind Turbines with Doubly Fed Inductive Generators Based on Model Predictive Control

    Directory of Open Access Journals (Sweden)

    Guo Jiuwang

    2015-01-01

    Full Text Available Because of the randomness and fluctuation of wind energy, as well as the impact of strongly nonlinear characteristic of variable speed constant frequency (VSCF wind power generation system with doubly fed induction generators (DFIG, traditional active power control strategies are difficult to achieve high precision control and the output power of wind turbines is more fluctuated. In order to improve the quality of output electric energy of doubly fed wind turbines, on the basis of analyzing the operating principles and dynamic characteristics of doubly fed wind turbines, this paper proposes a new active power optimal control method of doubly fed wind turbines based on predictive control theory. This method uses state space model of wind turbines, based on the prediction of the future state of wind turbines, moves horizon optimization, and meanwhile, gets the control signals of pitch angle and generator torque. Simulation results show that the proposed control strategies can guarantee the utilization efficiency for wind energy. Simultaneously, they can improve operation stability of wind turbines and the quality of electric energy.

  17. Robust Power Management Control for Stand-Alone Hybrid Power Generation System

    Science.gov (United States)

    Kamal, Elkhatib; Adouane, Lounis; Aitouche, Abdel; Mohammed, Walaa

    2017-01-01

    This paper presents a new robust fuzzy control of energy management strategy for the stand-alone hybrid power systems. It consists of two levels named centralized fuzzy supervisory control which generates the power references for each decentralized robust fuzzy control. Hybrid power systems comprises: a photovoltaic panel and wind turbine as renewable sources, a micro turbine generator and a battery storage system. The proposed control strategy is able to satisfy the load requirements based on a fuzzy supervisor controller and manage power flows between the different energy sources and the storage unit by respecting the state of charge and the variation of wind speed and irradiance. Centralized controller is designed based on If-Then fuzzy rules to manage and optimize the hybrid power system production by generating the reference power for photovoltaic panel and wind turbine. Decentralized controller is based on the Takagi-Sugeno fuzzy model and permits us to stabilize each photovoltaic panel and wind turbine in presence of disturbances and parametric uncertainties and to optimize the tracking reference which is given by the centralized controller level. The sufficient conditions stability are formulated in the format of linear matrix inequalities using the Lyapunov stability theory. The effectiveness of the proposed Strategy is finally demonstrated through a SAHPS (stand-alone hybrid power systems) to illustrate the effectiveness of the overall proposed method.

  18. Doubly Fed Induction Generator Wind Turbines with Fuzzy Controller: A Survey

    Directory of Open Access Journals (Sweden)

    J. S. Sathiyanarayanan

    2014-01-01

    Full Text Available Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG due to their advantages over other wind turbine generators (WTGs. Therefore, the analysis of wind power dynamics with the DFIG wind turbines has become a very important research issue, especially during transient faults. This paper presents fuzzy logic control of doubly fed induction generator (DFIG wind turbine in a sample power system. Fuzzy logic controller is applied to rotor side converter for active power control and voltage regulation of wind turbine.

  19. Doubly fed induction generator wind turbines with fuzzy controller: a survey.

    Science.gov (United States)

    Sathiyanarayanan, J S; Kumar, A Senthil

    2014-01-01

    Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG) due to their advantages over other wind turbine generators (WTGs). Therefore, the analysis of wind power dynamics with the DFIG wind turbines has become a very important research issue, especially during transient faults. This paper presents fuzzy logic control of doubly fed induction generator (DFIG) wind turbine in a sample power system. Fuzzy logic controller is applied to rotor side converter for active power control and voltage regulation of wind turbine.

  20. Generation and control of multi-scroll chaotic attractors in fractional order systems

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Wajdi M. [Department of Electrical and Computer Engineering, University of Sharjah, P.O. Box 27272, Sharjah (United Arab Emirates)] e-mail: wajdi@sharjah.ac.ae

    2005-08-01

    The objective of this paper is twofold: on one hand we demonstrate the generation of multi-scroll attractors in fractional order chaotic systems. Then, we design state feedback controllers to eliminate chaos from the system trajectories. It is demonstrated that modifying the underlying nonlinearity of the fractional chaotic system results in the birth of multiple chaotic attractors, thus forming the so called multi-scroll attractors. The presence of chaotic behavior is evidenced by a positive largest Lyapunov exponent computed for the output time series. We investigate generation and control of multi-scroll attractors in two different models, both of which are fractional order and chaotic: an electronic oscillator, and a mechanical 'jerk' model. The current findings extend previously reported results on generation of n-scroll attractors from the domain of integer order to the domain of fractional order chaotic systems, and addresses the issue of controlling such chaotic behaviors. Our investigations are validated through numerical simulations.

  1. Study of scratch-induced stress corrosion cracking for steam generator tubes and scratch control

    Energy Technology Data Exchange (ETDEWEB)

    Meng, F.; Xu, X.; Liu, X. [Shanghai Nuclear Engineering Research and Design Institute, Shanghai (China); Wang, J. [Chinese Academy of Sciences, Institute of Metal Research, Shenyang (China)

    2014-07-01

    This paper introduces field cases for scratch-induced stress corrosion cracking (SISCC) of steam generator tubes in PWR and current studies in laboratories. According to analysis result of broke tubes, scratches caused intergranular stress corrosion cracking (IGSCC) with outburst. The effect of microstructure for nickel-base alloys, residual stresses caused by scratching process and water chemistry on SISCC and possible mechanism of SISCC are discussed. The result shows that scratch-induced microstructure evolution contributes to SISCC significantly. The causes of scratches during steam generator tubing manufacturing and installation process are stated and improved reliability with scratch control is highlighted for steam generator tubes in newly built nuclear power plants. (author)

  2. Research on Operation Principle and Control of Novel Hybrid Excitation Bearingless Permanent Magnet Generator

    Directory of Open Access Journals (Sweden)

    Huangqiu Zhu

    2016-08-01

    Full Text Available Under the condition of load changing, the magnetic field of traditional permanent magnet generators (PMG is hard to be adjusted, and the mechanical bearings are significantly worn. To overcome the drawbacks above, a novel hybrid excitation bearingless permanent magnet generator (HEBPMG is proposed in this paper, which has integrated the merits of hybrid excitation permanent magnet generators and magnetic bearings. Firstly, the structure and winding configuration of the HEBPMG are introduced, and then the principles of radial suspension and power generation are presented. The suspension principle as well as power generation principle is analyzed in this paper. Then, the flux linkage and induced voltage equations are derived, and the accurate mathematical model of radial suspension force is built based on the Maxwell tensor method. Subsequently, by means of the finite element analysis software-ANSYS Maxwell, the corresponding electromagnetic characteristics are analyzed to verify the correctness of the mentioned models. In addition, a compensation control strategy based on flux-linkage observation is proposed to solve the problems of unstable suspension force and generating voltage under variable load condition in this paper. Meanwhile, the corresponding control system is constructed and its feasibility is validated by simulation results. Finally, an experimental prototype of a 2.2 kW HEBPMG is tested. Experimental researches show that the HEBPMG can operate steadily under variable load condition and possess good suspension performance and power generation quality.

  3. Supervisory control of a variable speed wind turbine with doubly fed induction generator

    Directory of Open Access Journals (Sweden)

    C. Viveiros

    2015-11-01

    Full Text Available This paper is on an onshore variable speed wind turbine with doubly fed induction generator and under supervisory control. The control architecture is equipped with an event-based supervisor for the supervision level and fuzzy proportional integral or discrete adaptive linear quadratic as proposed controllers for the execution level. The supervisory control assesses the operational state of the variable speed wind turbine and sends the state to the execution level. Controllers operation are in the full load region to extract energy at full power from the wind while ensuring safety conditions required to inject the energy into the electric grid. A comparison between the simulations of the proposed controllers with the inclusion of the supervisory control on the variable speed wind turbine benchmark model is presented to assess advantages of these controls.

  4. Coordinated control and experimentation of the dental arch generator of the tooth-arrangement robot.

    Science.gov (United States)

    Zhang, Yong-de; Jiang, Jin-gang; Lv, Pei-jun; Wang, Yong

    2010-12-01

    The traditional way of acquiring the dental arch curve form is based on manual operation, which will randomly bring numerous errors caused by human factors. The purpose of this paper is to automatically acquire the dental arch curve and implement the coordinated control of the dental arch generator of the multi-manipulator tooth-arrangement robot, which can be used in full denture manufacturing. Based on the arc length constant theory, kinematics on dental arch generator is analyzed. The control pulse realization methods of high-resolution timing and CPU time-stamp timing are studied, and testing and comparative analysis of the control precision and stability of the two methods is carried out. Control experimentation of the dental arch generator and preliminary tooth-arrangement experimentation are performed using the multi-manipulator tooth-arrangement robot system. The dental arch generator can automatically generate a dental arch curve that fits a patient according to the patient's jaw arch parameters. Repeated positioning accuracy is 0.12 mm for the slipways which drive the dental arch generator. The maximum value of single point error is 1.64 mm when the arc width direction (x-axis) is 37.25 mm. The experimental results indicate that the method of control pulse realized by high-resolution timing to achieve high precision coordinated motion control of dental arch generator of tooth-arrangement robot is feasible. The error analysis results indicate that the control strategy and technical route can fulfill the requirements for motion speed and location precision. A novel system to generate the tooth arch curve has been developed. The traditional method of manually determining the dental arch may soon become obsolete in favour of the use of a robot to assist in generating a more standard tooth arch curve. The system can be used to manufacture a full denture. It will lay an important theoretical foundation for quantitative research of oral restoration, and also

  5. Controls on Water Use for Thermoelectric Generation: Case Study Texas, U.S.

    Science.gov (United States)

    2013-01-01

    Large-scale U.S. dependence on thermoelectric (steam electric) generation requiring water for cooling underscores the need to understand controls on this water use. The study objective was to quantify water consumption and withdrawal for thermoelectric generation, identifying controls, using Texas as a case study. Water consumption for thermoelectricity in Texas in 2010 totaled ∼0.43 million acre feet (maf; 0.53 km3), accounting for ∼4% of total state water consumption. High water withdrawals (26.2 maf, 32.3 km3) mostly reflect circulation between ponds and power plants, with only two-thirds of this water required for cooling. Controls on water consumption include (1) generator technology/thermal efficiency and (2) cooling system, resulting in statewide consumption intensity for natural gas combined cycle generators with mostly cooling towers (0.19 gal/kWh) being 63% lower than that of traditional coal, nuclear, or natural gas steam turbine generators with mostly cooling ponds (0.52 gal/kWh). The primary control on water withdrawals is cooling system, with ∼2 orders of magnitude lower withdrawals for cooling towers relative to once-through ponds statewide. Increases in natural gas combined cycle plants with cooling towers in response to high production of low-cost natural gas has greatly reduced water demand for thermoelectric cooling since 2000. PMID:23937226

  6. Controls on water use for thermoelectric generation: case study Texas, US.

    Science.gov (United States)

    Scanlon, Bridget R; Reedy, Robert C; Duncan, Ian; Mullican, William F; Young, Michael

    2013-10-01

    Large-scale U.S. dependence on thermoelectric (steam electric) generation requiring water for cooling underscores the need to understand controls on this water use. The study objective was to quantify water consumption and withdrawal for thermoelectric generation, identifying controls, using Texas as a case study. Water consumption for thermoelectricity in Texas in 2010 totaled ∼0.43 million acre feet (maf; 0.53 km(3)), accounting for ∼4% of total state water consumption. High water withdrawals (26.2 maf, 32.3 km(3)) mostly reflect circulation between ponds and power plants, with only two-thirds of this water required for cooling. Controls on water consumption include (1) generator technology/thermal efficiency and (2) cooling system, resulting in statewide consumption intensity for natural gas combined cycle generators with mostly cooling towers (0.19 gal/kWh) being 63% lower than that of traditional coal, nuclear, or natural gas steam turbine generators with mostly cooling ponds (0.52 gal/kWh). The primary control on water withdrawals is cooling system, with ∼2 orders of magnitude lower withdrawals for cooling towers relative to once-through ponds statewide. Increases in natural gas combined cycle plants with cooling towers in response to high production of low-cost natural gas has greatly reduced water demand for thermoelectric cooling since 2000.

  7. Fuzzy Logic Controller Based Distributed Generation Integration Strategy for Stochastic Performance Improvement

    Directory of Open Access Journals (Sweden)

    Jagdish Prasad Sharma

    2016-01-01

    Full Text Available In the restructured environment, distributed generation (DG is considered as a very promising option due to a high initial capital cost of conventional plants, environmental concerns, and power shortage. Apart from the above, distributed generation (DG has also abilities to improve performance of feeder. Most of the distribution feeders have radial structure, which compel to observe the impact of distributed generations on feeder performance, having different characteristics and composition of time varying static ZIP load models. Two fuzzy-based expert system is proposed for selecting and ranking the most appropriated periods to an integration of distributed generations with a feeder. Madami type fuzzy logic controller was developed for sizing of distributed generation, whereas Sugeno type fuzzy logic controller was developed for the DG location. Input parameters for Madami fuzzy logic controller are substation reserve capacity, feeder power loss to load ratio, voltage unbalance, and apparent power imbalances. DG output, survivability index, and node distance from substation are chosen as input to Sugeno type fuzzy logic controller. The stochastic performance of proposed fuzzy expert systems was evaluated on a modified IEEE 37 node test feeder with 15 minutes characteristics time interval varying static ZIP load models.

  8. Blowing jets as a circulation flow control to enhancement the lift of wing or generated power of wind turbine

    Directory of Open Access Journals (Sweden)

    Alexandru DUMITRACHE

    2014-06-01

    Full Text Available The goal of this paper is to provide a numerical flow analysis based on RANS equations in two directions: the study of augmented high-lift system for a cross-section airfoil of a wing up to transonic regime and the circulation control implemented by tangentially blowing jet over a highly curved surface due to Coanda effect on a rotor blade for a wind turbine. This study were analyzed the performance, sensitivities and limitations of the circulation control method based on blowing jet for a fixed wing as well as for a rotating wing. Directions of future research are identified and discussed.

  9. Photochromic metal-organic frameworks: reversible control of singlet oxygen generation.

    Science.gov (United States)

    Park, Jihye; Feng, Dawei; Yuan, Shuai; Zhou, Hong-Cai

    2015-01-07

    The controlled generation of singlet oxygen is of great interest owing to its potential applications including industrial wastewater treatment, photochemistry, and photodynamic therapy. Two photochromic metal-organic frameworks, PC-PCN and SO-PCN, have been developed. A photochromic reaction has been successfully realized in PC-PCN while maintaining its single crystallinity. In particular, as a solid-state material which inherently integrates the photochromic switch and photosensitizer, SO-PCN has demonstrated reversible control of (1)O2 generation. Additionally, SO-PCN shows catalytic activity towards photooxidation of 1,5-dihydroxynaphthalene. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Summary report of working group 5: Beam and radiation generation, monitoring, and control

    Energy Technology Data Exchange (ETDEWEB)

    Church, Mike; /Fermilab; Kim, Ki-Yong; /Maryland U.

    2010-01-01

    This paper summarizes the activities and presentations of Working Group 5 of the Advanced Accelerator Concepts Workshop held at Annapolis, Maryland in June 2010. Working Group 5 touched on a broad range of topics in the fields of beam and radiation generation and their monitoring and control. These topics were not comprehensively covered in this Workshop, but rather the Working Group concentrated on specific new developments and recent investigations. The Working Group divided its sessions into four broad categories: cathodes and electron guns, radiation generation, beam diagnostics, and beam control and dynamics. This summary is divided into the same structure.

  11. Repetitive transcranial magnetic stimulation (rTMS) augmentation of selective serotonin reuptake inhibitors (SSRIs) for SSRI-resistant obsessive-compulsive disorder (OCD): a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Ma, Zhong-Rui; Shi, Li-Jun

    2014-01-01

    Randomized controlled trials (RCTs) on repetitive transcranial magnetic stimulation (rTMS) as augmentation of selective serotonin reuptake inhibitors (SSRIs) for SSRI-resistant obsessive-compulsive disorder (OCD) have yielded conflicting results. Therefore, this meta-analysis was conducted to assess the efficacy of this strategy for SSRI-resistant OCD. Scientific and medical databases, including international databases (PubMed, MEDLINE, EMBASE, CCTR, Web of Science, PsycINFO), two Chinese databases (CBM-disc, CNKI), and relevant websites dated up to July 2014, were searched for RCTs on this strategy for treating OCD. Mantel-Haenszel random-effects model was used. Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score, response rates and drop-out rates were evaluated. Data were obtained from nine RCTs consisting of 290 subjects. Active rTMS was an effective augmentation strategy in treating SSRI-resistant OCD with a pooled WMD of 3.89 (95% CI = [1.27, 6.50]) for reducing Y-BOCS score and a pooled odds ratio (OR) of 2.65 (95% CI = [1.36, 5.17] for response rates. No significant differences in drop-out rates were found. No publication bias was detected. The pooled examination demonstrated that this strategy seems to be efficacious and acceptable for treating SSRI-resistant OCD. As the number of RCTs included here was limited, further large-scale multi-center RCTs are required to validate our conclusions.

  12. SPRINT spray intercooling augments LM6000 output

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David

    1998-09-01

    By injecting water between the low pressure and high pressure compressors of an aeroderivative gas turbine, GE-IAD engineers have demonstrated that a 9 per cent increase in output accompanied by reduced life cycle costs can be achieved. Designated the SPRINT system, uprated LM 6000 units with augmented efficiency have been introduced to the market. The first two production units, both supplied to Southern Electric Power Generation in England for mid-merit independent power generation plants at Chickerell in Dorset and Burghfield in Berkshire, have each clocked in excess of 500 operating hours since start-up in early April 1998. MPS visited the Chickerell installation in late July 1998. (UK)

  13. C code generation from Petri-net-based logic controller specification

    Science.gov (United States)

    Grobelny, Michał; Grobelna, Iwona; Karatkevich, Andrei

    2017-08-01

    The article focuses on programming of logic controllers. It is important that a programming code of a logic controller is executed flawlessly according to the primary specification. In the presented approach we generate C code for an AVR microcontroller from a rule-based logical model of a control process derived from a control interpreted Petri net. The same logical model is also used for formal verification of the specification by means of the model checking technique. The proposed rule-based logical model and formal rules of transformation ensure that the obtained implementation is consistent with the already verified specification. The approach is validated by practical experiments.

  14. Shuttle Flight Operations Contract Generator Maintenance Facility Land Use Control Implementation Plan (LUCIP)

    Science.gov (United States)

    Applegate, Joseph L.

    2014-01-01

    This Land Use Control Implementation Plan (LUCIP) has been prepared to inform current and potential future users of the Kennedy Space Center (KSC) Shuttle Flight Operations Contract Generator Maintenance Facility (SFOC; SWMU 081; "the Site") of institutional controls that have been implemented at the Site1. Although there are no current unacceptable risks to human health or the environment associated with the SFOC, an institutional land use control (LUC) is necessary to prevent human health exposure to antimony-affected groundwater at the Site. Controls will include periodic inspection, condition certification, and agency notification.

  15. Unbalanced voltage control of virtual synchronous generator in isolated micro-grid

    Science.gov (United States)

    Cao, Y. Z.; Wang, H. N.; Chen, B.

    2017-06-01

    Virtual synchronous generator (VSG) control is recommended to stabilize the voltage and frequency in isolated micro-grid. However, common VSG control is challenged by widely used unbalance loads, and the linked unbalance voltage problem worsens the power quality of the micro-grid. In this paper, the mathematical model of VSG was presented. Based on the analysis of positive- and negative-sequence equivalent circuit of VSG, an approach was proposed to eliminate the negative-sequence voltage of VSG with unbalance loads. Delay cancellation method and PI controller were utilized to identify and suppress the negative-sequence voltages. Simulation results verify the feasibility of proposed control strategy.

  16. Comparison of control strategies for Doubly fed induction generator under recurring grid faults

    DEFF Research Database (Denmark)

    Chen, Wenjie; Blaabjerg, Frede; Zhu, Nan

    2014-01-01

    The new grid codes demand the wind turbine systems to ride through recurring grid faults. Many control strategies have been proposed for the Doubly Fed Induction Generator under single grid fault, but their performance under recurring grid faults have not been studied yet. In this paper, five...... different control strategies for DFIG to ride through single grid faults are presented, and their performance under recurring grid faults are analyzed. The controllable range, stator time constant and torque fluctuations of the DFIG with different control strategies are compared. The results are verified...

  17. Low Voltage Ride-through in DFIG Wind Generators by Controlling the Rotor Current without Crowbars

    Directory of Open Access Journals (Sweden)

    Jaime Rodríguez Arribas

    2014-01-01

    Full Text Available Among all the different types of electric wind generators, those that are based on doubly fed induction generators, or DFIG technology, are the most vulnerable to grid faults such as voltage sags. This paper proposes a new control strategy for this type of wind generator, that allows these devices to withstand the effects of a voltage sag while following the new requirements imposed by grid operators. This new control strategy makes the use of complementary devices such as crowbars unnecessary, as it greatly reduces the value of currents originated by the fault. This ensures less costly designs for the rotor systems as well as a more economic sizing of the necessary power electronics. The strategy described here uses an electric generator model based on space-phasor theory that provides a direct control over the position of the rotor magnetic flux. Controlling the rotor magnetic flux has a direct influence on the rest of the electrical variables enabling the machine to evolve to a desired work point during the transient imposed by the grid disturbance. Simulation studies have been carried out, as well as test bench trials, in order to prove the viability and functionality of the proposed control strategy.

  18. Augmented Virtual Reality Laboratory

    Science.gov (United States)

    Tully-Hanson, Benjamin

    2015-01-01

    Real time motion tracking hardware has for the most part been cost prohibitive for research to regularly take place until recently. With the release of the Microsoft Kinect in November 2010, researchers now have access to a device that for a few hundred dollars is capable of providing redgreenblue (RGB), depth, and skeleton data. It is also capable of tracking multiple people in real time. For its original intended purposes, i.e. gaming, being used with the Xbox 360 and eventually Xbox One, it performs quite well. However, researchers soon found that although the sensor is versatile, it has limitations in real world applications. I was brought aboard this summer by William Little in the Augmented Virtual Reality (AVR) Lab at Kennedy Space Center to find solutions to these limitations.

  19. Today in breast augmentation

    Directory of Open Access Journals (Sweden)

    Juan Manuel Calderón

    2016-02-01

    Full Text Available Breast augmentation is one of the most commonly performed procedures worldwide among aesthetic reconstructive surgeries. Among the indications for performing the procedure are primary and secondary alterations related to breasts shape and volume. During the initial assessment, emphasis should be placed in the anamnesis and physical examination, allowing to define target sizing and realistic expectations to prospectively determine the possible postoperative satisfaction rates. There are several methods used to select the appropriate implants that have become more accurate with time and with the use of technology. Although there are multiple materials developed, to this moment silicone implants continue to be the ones most used worldwide with low complication rates depending on each patient and on the technique used. It is considered as one of the aesthetic reconstructive surgeries with the highest degree of acceptance among the general population who undergo this type of procedures.

  20. Augmented nonlinear differentiator design

    Science.gov (United States)

    Shao, Xingling; Liu, Jun; Yang, Wei; Tang, Jun; Li, Jie

    2017-06-01

    This paper presents a sigmoid function based augmented nonlinear differentiator (AND) for calculating the noise-less time derivative from a noisy measurement. The prominent advantages of the present differentiation technique are: (i) compared to the existing tracking differentiators, better noise suppression ability can be achieved without appreciable delay; (ii) the enhanced noise-filtering mechanism not only can be applied to the designed differentiator, but also can be extended for improving noise-tolerance capability of the available differentiators. In addition, the convergence property and robustness performance against noises are investigated via singular perturbation theory and describing function method, respectively. Also, comparison with several classical differentiators is given to illustrate the superiority of AND in noise suppression. Finally, applications on autopilot design and displacement following for nonlinear mass spring mechanical system are given to demonstrate the effectiveness and applicability of the proposed AND technique.