WorldWideScience

Sample records for regulatory control loop

  1. A regulatory transcriptional loop controls proliferation and differentiation in Drosophila neural stem cells.

    Directory of Open Access Journals (Sweden)

    Tetsuo Yasugi

    Full Text Available Neurogenesis is initiated by a set of basic Helix-Loop-Helix (bHLH transcription factors that specify neural progenitors and allow them to generate neurons in multiple rounds of asymmetric cell division. The Drosophila Daughterless (Da protein and its mammalian counterparts (E12/E47 act as heterodimerization factors for proneural genes and are therefore critically required for neurogenesis. Here, we demonstrate that Da can also be an inhibitor of the neural progenitor fate whose absence leads to stem cell overproliferation and tumor formation. We explain this paradox by demonstrating that Da induces the differentiation factor Prospero (Pros whose asymmetric segregation is essential for differentiation in one of the two daughter cells. Da co-operates with the bHLH transcription factor Asense, whereas the other proneural genes are dispensible. After mitosis, Pros terminates Asense expression in one of the two daughter cells. In da mutants, pros is not expressed, leading to the formation of lethal transplantable brain tumors. Our results define a transcriptional feedback loop that regulates the balance between self-renewal and differentiation in Drosophila optic lobe neuroblasts. They indicate that initiation of a neural differentiation program in stem cells is essential to prevent tumorigenesis.

  2. Analytical design of an industrial two-term controller for optimal regulatory control of open-loop unstable processes under operational constraints.

    Science.gov (United States)

    Tchamna, Rodrigue; Lee, Moonyong

    2018-01-01

    This paper proposes a novel optimization-based approach for the design of an industrial two-term proportional-integral (PI) controller for the optimal regulatory control of unstable processes subjected to three common operational constraints related to the process variable, manipulated variable and its rate of change. To derive analytical design relations, the constrained optimal control problem in the time domain was transformed into an unconstrained optimization problem in a new parameter space via an effective parameterization. The resulting optimal PI controller has been verified to yield optimal performance and stability of an open-loop unstable first-order process under operational constraints. The proposed analytical design method explicitly takes into account the operational constraints in the controller design stage and also provides useful insights into the optimal controller design. Practical procedures for designing optimal PI parameters and a feasible constraint set exclusive of complex optimization steps are also proposed. The proposed controller was compared with several other PI controllers to illustrate its performance. The robustness of the proposed controller against plant-model mismatch has also been investigated. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  3. A Positive Regulatory Loop between a Wnt-Regulated Non-coding RNA and ASCL2 Controls Intestinal Stem Cell Fate.

    Science.gov (United States)

    Giakountis, Antonis; Moulos, Panagiotis; Zarkou, Vasiliki; Oikonomou, Christina; Harokopos, Vaggelis; Hatzigeorgiou, Artemis G; Reczko, Martin; Hatzis, Pantelis

    2016-06-21

    The canonical Wnt pathway plays a central role in stem cell maintenance, differentiation, and proliferation in the intestinal epithelium. Constitutive, aberrant activity of the TCF4/β-catenin transcriptional complex is the primary transforming factor in colorectal cancer. We identify a nuclear long non-coding RNA, termed WiNTRLINC1, as a direct target of TCF4/β-catenin in colorectal cancer cells. WiNTRLINC1 positively regulates the expression of its genomic neighbor ASCL2, a transcription factor that controls intestinal stem cell fate. WiNTRLINC1 interacts with TCF4/β-catenin to mediate the juxtaposition of its promoter with the regulatory regions of ASCL2. ASCL2, in turn, regulates WiNTRLINC1 transcriptionally, closing a feedforward regulatory loop that controls stem cell-related gene expression. This regulatory circuitry is highly amplified in colorectal cancer and correlates with increased metastatic potential and decreased patient survival. Our results uncover the interplay between non-coding RNA-mediated regulation and Wnt signaling and point to the diagnostic and therapeutic potential of WiNTRLINC1. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Dynamic PID loop control

    International Nuclear Information System (INIS)

    Pei, L.; Klebaner, A.; Theilacker, J.; Soyars, W.; Martinez, A.; Bossert, R.; DeGraff, B.; Darve, C.

    2011-01-01

    The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters oscillation.

  5. How short RNAs impact the human ribonuclease Dicer activity: putative regulatory feedback-loops and other RNA-mediated mechanisms controlling microRNA processing.

    Science.gov (United States)

    Koralewska, Natalia; Hoffmann, Weronika; Pokornowska, Maria; Milewski, Marek; Lipinska, Andrea; Bienkowska-Szewczyk, Krystyna; Figlerowicz, Marek; Kurzynska-Kokorniak, Anna

    2016-01-01

    Ribonuclease Dicer plays a pivotal role in RNA interference pathways by processing long double-stranded RNAs and single-stranded hairpin RNA precursors into small interfering RNAs (siRNAs) and microRNAs (miRNAs), respectively. While details of Dicer regulation by a variety of proteins are being elucidated, less is known about non-protein factors, e.g. RNA molecules, that may influence this enzyme's activity. Therefore, we decided to investigate the question of whether the RNA molecules can function not only as Dicer substrates but also as its regulators. Our previous in vitro studies indicated that the activity of human Dicer can be influenced by short RNA molecules that either bind to Dicer or interact with its substrates, or both. Those studies were carried out with commercial Dicer preparations. Nevertheless, such preparations are usually not homogeneous enough to carry out more detailed RNA-binding studies. Therefore, we have established our own system for the production of human Dicer in insect cells. In this manuscript, we characterize the RNA-binding and RNA-cleavage properties of the obtained preparation. We demonstrate that Dicer can efficiently bind single-stranded RNAs that are longer than ~20-nucleotides. Consequently, we revisit possible scenarios of Dicer regulation by single-stranded RNA species ranging from ~10- to ~60-nucleotides, in the context of their binding to this enzyme. Finally, we show that siRNA/miRNA-sized RNAs may affect miRNA production either by binding to Dicer or by participating in regulatory feedback-loops. Altogether, our studies suggest a broad regulatory role of short RNAs in Dicer functioning.

  6. Laser welding closed-loop power control

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    2003-01-01

    A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser.......A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser....

  7. Hydraulic loop: practices using open control systems

    International Nuclear Information System (INIS)

    Carrasco, J.A.; Alonso, L.; Sanchez, F.

    1998-01-01

    The Tecnatom Hydraulic Loop is a dynamic training platform. It has been designed with the purpose of improving the work in teams. With this system, the student can obtain a full scope vision of a system. The hydraulic Loop is a part of the Tecnatom Maintenance Centre. The first objective of the hydraulic Loop is the instruction in components, process and process control using open control system. All the personal of an electric power plant can be trained in the Hydraulic Loop with specific courses. The development of a dynamic tool for tests previous to plant installations has been an additional objective of the Hydraulic Loop. The use of this platform is complementary to the use of full-scope simulators in order to debug and to analyse advanced control strategies. (Author)

  8. A keyboard control method for loop measurement

    International Nuclear Information System (INIS)

    Gao, Z.W.

    1994-01-01

    This paper describes a keyboard control mode based on the DEC VAX computer. The VAX Keyboard code can be found under running of a program was developed. During the loop measurement or multitask operation, it ables to be distinguished from a keyboard code to stop current operation or transfer to another operation while previous information can be held. The combining of this mode, the author successfully used one key control loop measurement for test Dual Input Memory module which is used in a rearrange Energy Trigger system for LEP 8 Bunch operation

  9. Prognostics in the Control Loop

    Data.gov (United States)

    National Aeronautics and Space Administration — The term Automated Contingency Management (ACM) has been used to describe intelligent systems capable of mission re-planning and control reconfiguration in the...

  10. Survivability of SCADA Control Loop

    NARCIS (Netherlands)

    Camacho, José; de Boer, Pieter-Tjerk; Remke, Anne Katharina Ingrid

    2009-01-01

    The endorsement of information technologies for critical infrastructures control introduces new threats in their security and surveillance. Along with certain level of protection against attacks, it is desirable for critical processes to survive even if they succeed. A stochastic Petri Nets-based

  11. Controllability analysis of transcriptional regulatory networks reveals circular control patterns among transcription factors

    DEFF Research Database (Denmark)

    Österlund, Tobias; Bordel, Sergio; Nielsen, Jens

    2015-01-01

    % for the human network. The high controllability (low number of drivers needed to control the system) in yeast, mouse and human is due to the presence of internal loops in their regulatory networks where the TFs regulate each other in a circular fashion. We refer to these internal loops as circular control...... motifs (CCM). The E. coli transcriptional regulatory network, which does not have any CCMs, shows a hierarchical structure of the transcriptional regulatory network in contrast to the eukaryal networks. The presence of CCMs also has influence on the stability of these networks, as the presence of cycles...

  12. Radiation practices and regulatory control

    International Nuclear Information System (INIS)

    1997-01-01

    The general principles to be observed in the regulatory control of ionizing radiation use and practices are specified in the guide. It also takes into account of additions and alterations needed for for compliance with the European Union (EU) directives that have not been mentioned in other STUK/ST-guides. (6 refs.)

  13. Radiation practices and regulatory control

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The general principles to be observed in the regulatory control of ionizing radiation use and practices are specified in the guide. It also takes into account of additions and alterations needed for for compliance with the European Union (EU) directives that have not been mentioned in other STUK/ST-guides. (6 refs.).

  14. Online control loop tuning in Pickering Nuclear Generating Stations

    International Nuclear Information System (INIS)

    Yu, K.X.; Harrington, S.

    2008-01-01

    Most analog controllers in the Pickering B Nuclear Generating Stations adopted PID control scheme. In replacing the analog controllers with digital controllers, the PID control strategies, including the original tuning parameters were retained. The replacement strategy resulted in minimum effort on control loop tuning. In a few cases, however, it was found during commissioning that control loop tuning was required as a result of poor control loop performance, typically due to slow response and controlled process oscillation. Several factors are accounted for the necessities of control loop re-tuning. Our experience in commissioning the digital controllers showed that online control tuning posted some challenges in nuclear power plant. (author)

  15. ACSYNT inner loop flight control design study

    Science.gov (United States)

    Bortins, Richard; Sorensen, John A.

    1993-01-01

    The NASA Ames Research Center developed the Aircraft Synthesis (ACSYNT) computer program to synthesize conceptual future aircraft designs and to evaluate critical performance metrics early in the design process before significant resources are committed and cost decisions made. ACSYNT uses steady-state performance metrics, such as aircraft range, payload, and fuel consumption, and static performance metrics, such as the control authority required for the takeoff rotation and for landing with an engine out, to evaluate conceptual aircraft designs. It can also optimize designs with respect to selected criteria and constraints. Many modern aircraft have stability provided by the flight control system rather than by the airframe. This may allow the aircraft designer to increase combat agility, or decrease trim drag, for increased range and payload. This strategy requires concurrent design of the airframe and the flight control system, making trade-offs of performance and dynamics during the earliest stages of design. ACSYNT presently lacks means to implement flight control system designs but research is being done to add methods for predicting rotational degrees of freedom and control effector performance. A software module to compute and analyze the dynamics of the aircraft and to compute feedback gains and analyze closed loop dynamics is required. The data gained from these analyses can then be fed back to the aircraft design process so that the effects of the flight control system and the airframe on aircraft performance can be included as design metrics. This report presents results of a feasibility study and the initial design work to add an inner loop flight control system (ILFCS) design capability to the stability and control module in ACSYNT. The overall objective is to provide a capability for concurrent design of the aircraft and its flight control system, and enable concept designers to improve performance by exploiting the interrelationships between

  16. Dual Nature of Translational Control by Regulatory BC RNAs ▿

    Science.gov (United States)

    Eom, Taesun; Berardi, Valerio; Zhong, Jun; Risuleo, Gianfranco; Tiedge, Henri

    2011-01-01

    In higher eukaryotes, increasing evidence suggests, gene expression is to a large degree controlled by RNA. Regulatory RNAs have been implicated in the management of neuronal function and plasticity in mammalian brains. However, much of the molecular-mechanistic framework that enables neuronal regulatory RNAs to control gene expression remains poorly understood. Here, we establish molecular mechanisms that underlie the regulatory capacity of neuronal BC RNAs in the translational control of gene expression. We report that regulatory BC RNAs employ a two-pronged approach in translational control. One of two distinct repression mechanisms is mediated by C-loop motifs in BC RNA 3′ stem-loop domains. These C-loops bind to eIF4B and prevent the factor's interaction with 18S rRNA of the small ribosomal subunit. In the second mechanism, the central A-rich domains of BC RNAs target eIF4A, specifically inhibiting its RNA helicase activity. Thus, BC RNAs repress translation initiation in a bimodal mechanistic approach. As BC RNA functionality has evolved independently in rodent and primate lineages, our data suggest that BC RNA translational control was necessitated and implemented during mammalian phylogenetic development of complex neural systems. PMID:21930783

  17. Regulatory control of fuel design and manufacturing

    International Nuclear Information System (INIS)

    1994-01-01

    The regulatory control of the design and manufacturing of the nuclear fuel and of the control rods aims to ensure conformance to set requirements during normal operating conditions, anticipated operational transients and postulated accident conditions. The regulatory control of design, manufacturing, receiving inspections and the start of operation of the nuclear fuel are specified in the guide. The regulatory control procedure also applies to the control rods and the shield elements

  18. Current control loop of 3-phase grid-connected inverter

    International Nuclear Information System (INIS)

    Jabbar, A F; Mansor, M

    2013-01-01

    This paper presents a comparative study of current control loop in 3-phase inverter which is used to control the active and reactive output power. Generally, current control loop, power control loop and phase lock-loop are the conventional parameters that can be found in an inverter system controlled by the conventional linear control type, for instance proportional (P), integral (I) and derivative (D). If the grid remains stable throughout the day, PID control can be use. However variation of magnitude, frequency, voltage dips, transient, and other related power quality issues occur in a 3-phase grid often affects the control loop. This paper aims to provide an overall review on the available current control techniques used in grid connected system.

  19. DLX5, FGF8 and the Pin1 isomerase control ΔNp63α protein stability during limb development: a regulatory loop at the basis of the SHFM and EEC congenital malformations

    Science.gov (United States)

    Restelli, Michela; Lopardo, Teresa; Lo Iacono, Nadia; Garaffo, Giulia; Conte, Daniele; Rustighi, Alessandra; Napoli, Marco; Del Sal, Giannino; Perez-Morga, David; Costanzo, Antonio; Merlo, Giorgio Roberto; Guerrini, Luisa

    2014-01-01

    Ectrodactyly, or Split-Hand/Foot Malformation (SHFM), is a congenital condition characterized by the loss of central rays of hands and feet. The p63 and the DLX5;DLX6 transcription factors, expressed in the embryonic limb buds and ectoderm, are disease genes for these conditions. Mutations of p63 also cause the ectodermal dysplasia–ectrodactyly–cleft lip/palate (EEC) syndrome, comprising SHFM. Ectrodactyly is linked to defects of the apical ectodermal ridge (AER) of the developing limb buds. FGF8 is the key signaling molecule in this process, able to direct proximo-distal growth and patterning of the skeletal primordial of the limbs. In the limb buds of both p63 and Dlx5;Dlx6 murine models of SHFM, the AER is poorly stratified and FGF8 expression is severely reduced. We show here that the FGF8 locus is a downstream target of DLX5 and that FGF8 counteracts Pin1–ΔNp63α interaction. In vivo, lack of Pin1 leads to accumulation of the p63 protein in the embryonic limbs and ectoderm. We show also that ΔNp63α protein stability is negatively regulated by the interaction with the prolyl-isomerase Pin1, via proteasome-mediated degradation; p63 mutant proteins associated with SHFM or EEC syndromes are resistant to Pin1 action. Thus, DLX5, p63, Pin1 and FGF8 participate to the same time- and location-restricted regulatory loop essential for AER stratification, hence for normal patterning and skeletal morphogenesis of the limb buds. These results shed new light on the molecular mechanisms at the basis of the SHFM and EEC limb malformations. PMID:24569166

  20. DLX5, FGF8 and the Pin1 isomerase control ΔNp63α protein stability during limb development: a regulatory loop at the basis of the SHFM and EEC congenital malformations.

    Science.gov (United States)

    Restelli, Michela; Lopardo, Teresa; Lo Iacono, Nadia; Garaffo, Giulia; Conte, Daniele; Rustighi, Alessandra; Napoli, Marco; Del Sal, Giannino; Perez-Morga, David; Costanzo, Antonio; Merlo, Giorgio Roberto; Guerrini, Luisa

    2014-07-15

    Ectrodactyly, or Split-Hand/Foot Malformation (SHFM), is a congenital condition characterized by the loss of central rays of hands and feet. The p63 and the DLX5;DLX6 transcription factors, expressed in the embryonic limb buds and ectoderm, are disease genes for these conditions. Mutations of p63 also cause the ectodermal dysplasia-ectrodactyly-cleft lip/palate (EEC) syndrome, comprising SHFM. Ectrodactyly is linked to defects of the apical ectodermal ridge (AER) of the developing limb buds. FGF8 is the key signaling molecule in this process, able to direct proximo-distal growth and patterning of the skeletal primordial of the limbs. In the limb buds of both p63 and Dlx5;Dlx6 murine models of SHFM, the AER is poorly stratified and FGF8 expression is severely reduced. We show here that the FGF8 locus is a downstream target of DLX5 and that FGF8 counteracts Pin1-ΔNp63α interaction. In vivo, lack of Pin1 leads to accumulation of the p63 protein in the embryonic limbs and ectoderm. We show also that ΔNp63α protein stability is negatively regulated by the interaction with the prolyl-isomerase Pin1, via proteasome-mediated degradation; p63 mutant proteins associated with SHFM or EEC syndromes are resistant to Pin1 action. Thus, DLX5, p63, Pin1 and FGF8 participate to the same time- and location-restricted regulatory loop essential for AER stratification, hence for normal patterning and skeletal morphogenesis of the limb buds. These results shed new light on the molecular mechanisms at the basis of the SHFM and EEC limb malformations. © The Author 2014. Published by Oxford University Press.

  1. Regulatory Control of Radiation Sources. Safety Guide

    International Nuclear Information System (INIS)

    2009-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  2. Gain Scheduling Control based on Closed-Loop System Identification

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    the first and a second operating point is identified in closed-loop using system identification methods with open-loop properties. Next, a linear controller is designed for this linearised model, and gain scheduling control can subsequently be achieved by interpolating between each controller...

  3. Research and design of 3He pressure control loop

    International Nuclear Information System (INIS)

    Huang Xin; Zhang Peisheng; Tang Guoliang; Zhang Aimin; Zhang Yingchao

    2008-01-01

    In order to carry out power transient tests for PWR fuel element in China Advanced Research Reactor (CARR), the research and conceptual design of 3He pressure control loop were completed. The working principle, design parameters and technological flow of the loop were described. It is seen that the a He loop can adjust the power of the tested PWR fuel element rapidly, evenly and flexibly and it is an optimal path to realize the power transient regulation for tested PWR fuel. (authors)

  4. Open loop thanks to direct torque control (DTC). Motor control without feedback loop; Open loop dank direkter Drehmomentregelung (DTC). Hochwertige Motorregelung ohne Rueckfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Link, Michael [ABB Automation Products GmbH, Ladenburg (Germany)

    2009-07-01

    Servo drives are used in various applications. The range of applications is huge and thus also requirements to the drive system. Mainly, a fast torque and speed control is required. This is the domaine of direct torque control (DTC). In many applications DTC can meet this challenge to control the motor with full torque at zero speed. The servo converter based on DTC technology provides a control concept for synchronous and asynchronous motors for both closed loop and open loop control. DTC controlled drives support the whole range from open loop up to high performance motion control applications. (orig.)

  5. Control loop performance evaluation and diagnostic in the oil refining process; Avaliacao de desempenho e diagnostico das malhas de controle no processo de refino de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Regina Lucia de A.; Pavanelli, Paula E. [Chemtech, Rio de Janeiro, RJ (Brazil); Miranda, Filipe Costa Pinto dos R. [PETROBRAS S.A., Maua, SP (Brazil). Refinaria de Capuava (RECAP)

    2008-07-01

    Management Assets has been a theme treated with growing priority and importance by Processes Industry. Control loops are important assets to guarantee the security and operational stability of processes when they present a good performance. Usually there are a large number of control loops in processes units and their initial investment and maintenance costs are expensive. Human evaluation of control loops, in a non-systematic way, does not identify all the problems that can degrade regulatory control performance, and this the main reason to use systematic monitoring and evaluation techniques and software tools necessary to keep loops efficient. This work describes the continuous activity of monitoring and evaluation of the control systems of a petroleum refinery. Depending on some performance indexes, the loops are prioritized and some actions are taken (valve maintenance or tuning adjustment) to improve control loop performance and to avoid the reduction of product quality, raw material and utilities waste and even unit shutdown. (author)

  6. Voice loops as coordination aids in space shuttle mission control.

    Science.gov (United States)

    Patterson, E S; Watts-Perotti, J; Woods, D D

    1999-01-01

    Voice loops, an auditory groupware technology, are essential coordination support tools for experienced practitioners in domains such as air traffic management, aircraft carrier operations and space shuttle mission control. They support synchronous communication on multiple channels among groups of people who are spatially distributed. In this paper, we suggest reasons for why the voice loop system is a successful medium for supporting coordination in space shuttle mission control based on over 130 hours of direct observation. Voice loops allow practitioners to listen in on relevant communications without disrupting their own activities or the activities of others. In addition, the voice loop system is structured around the mission control organization, and therefore directly supports the demands of the domain. By understanding how voice loops meet the particular demands of the mission control environment, insight can be gained for the design of groupware tools to support cooperative activity in other event-driven domains.

  7. Control-structure interaction in precision pointing servo loops

    Science.gov (United States)

    Spanos, John T.

    1989-01-01

    The control-structure interaction problem is addressed via stability analysis of a generic linear servo loop model. With the plant described by the rigid body mode and a single elastic mode, structural flexibility is categorized into one of three types: (1) appendage, (2) in-the-loop minimum phase, and (3) in-the-loop nonminimum phase. Closing the loop with proportional-derivative (PD) control action and introducing sensor roll-off dynamics in the feedback path, stability conditions are obtained. Trade studies are conducted with modal frequency, modal participation, modal damping, loop bandwidth, and sensor bandwidth treated as free parameters. Results indicate that appendage modes are most likely to produce instability if they are near the sensor rolloff, whereas in-the-loop modes are most dangerous near the loop bandwidth. The main goal of this paper is to provide a fundamental understanding of the control-structure interaction problem so that it may benefit the design of complex spacecraft and pointing system servo loops. In this framework, the JPL Pathfinder gimbal pointer is considered as an example.

  8. Modulation of dynamic modes by interplay between positive and negative feedback loops in gene regulatory networks

    Science.gov (United States)

    Wang, Liu-Suo; Li, Ning-Xi; Chen, Jing-Jia; Zhang, Xiao-Peng; Liu, Feng; Wang, Wei

    2018-04-01

    A positive and a negative feedback loop can induce bistability and oscillation, respectively, in biological networks. Nevertheless, they are frequently interlinked to perform more elaborate functions in many gene regulatory networks. Coupled positive and negative feedback loops may exhibit either oscillation or bistability depending on the intensity of the stimulus in some particular networks. It is less understood how the transition between the two dynamic modes is modulated by the positive and negative feedback loops. We developed an abstract model of such systems, largely based on the core p53 pathway, to explore the mechanism for the transformation of dynamic behaviors. Our results show that enhancing the positive feedback may promote or suppress oscillations depending on the strength of both feedback loops. We found that the system oscillates with low amplitudes in response to a moderate stimulus and switches to the on state upon a strong stimulus. When the positive feedback is activated much later than the negative one in response to a strong stimulus, the system exhibits long-term oscillations before switching to the on state. We explain this intriguing phenomenon using quasistatic approximation. Moreover, early switching to the on state may occur when the system starts from a steady state in the absence of stimuli. The interplay between the positive and negative feedback plays a key role in the transitions between oscillation and bistability. Of note, our conclusions should be applicable only to some specific gene regulatory networks, especially the p53 network, in which both oscillation and bistability exist in response to a certain type of stimulus. Our work also underscores the significance of transient dynamics in determining cellular outcome.

  9. Nonlinear model predictive control for chemical looping process

    Science.gov (United States)

    Joshi, Abhinaya; Lei, Hao; Lou, Xinsheng

    2017-08-22

    A control system for optimizing a chemical looping ("CL") plant includes a reduced order mathematical model ("ROM") that is designed by eliminating mathematical terms that have minimal effect on the outcome. A non-linear optimizer provides various inputs to the ROM and monitors the outputs to determine the optimum inputs that are then provided to the CL plant. An estimator estimates the values of various internal state variables of the CL plant. The system has one structure adapted to control a CL plant that only provides pressure measurements in the CL loops A and B, a second structure adapted to a CL plant that provides pressure measurements and solid levels in both loops A, and B, and a third structure adapted to control a CL plant that provides full information on internal state variables. A final structure provides a neural network NMPC controller to control operation of loops A and B.

  10. Closed Loop Control of Oxygen Delivery and Oxygen Generation

    Science.gov (United States)

    2017-08-01

    were used for this study and were connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen...connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen based on the oxygen saturation...2017-4119, 28 Aug 2017. oximetry (SpO2) and intermittent arterial blood sampling for arterial oxygen tension (partial pressure of oxygen [PaO2]) and

  11. Analysis of Reconfigured Control Loop with a Virtual Actuator

    Directory of Open Access Journals (Sweden)

    Anna Filasova

    2011-01-01

    Full Text Available Control reconfiguration changes the control structure in response to a fault detected in the plant. This becomes necessary, because a major fault like loss of an actuator breaks the corresponding control loop and therefore renders the whole system inoperable.  An important aim of control reconfiguration is to change the control structure as little as possible, since every change bears the potential of practical problems. The proposed solution is to keep the original controller in the loop and to add an extension called virtual actuator that implements the necessary changes of the control structure. The virtual actuator translates between the signals of the nominal controller and the signal of the faulty plants. This paper is concerned with the analysis of reconfigured loop with a virtual actuator for the system with the faulty actuator. The proposed analysis is illustrated on numerical example.

  12. Resilience of Urban Smart Grids Involving Multiple Control Loops

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Pillai, Jayakrishnan Radhakrishna; Schwefel, Hans-Peter

    2016-01-01

    Intelligent control of energy distribution grids is implemented via a hierarchy of control loops with different input values and different control targets, which also work on different time-scales. This control is enabled by a bi-directional communication flow, which can be interrupted due to ICT...

  13. Regulatory control of nuclear power plants

    International Nuclear Information System (INIS)

    2002-01-01

    The purpose of this book is to support IAEA training courses and workshops in the field of regulatory control of nuclear power plants as well as to support the regulatory bodies of Member States in their own training activities. The target group is the professional staff members of nuclear safety regulatory bodies supervising nuclear power plants and having duties and responsibilities in the following regulatory fields: regulatory framework; regulatory organization; regulatory guidance; licensing and licensing documents; assessment of safety; and regulatory inspection and enforcement. Important topics such as regulatory competence and quality of regulatory work as well as emergency preparedness and public communication are also covered. The book also presents the key issues of nuclear safety such as 'defence-in-depth' and safety culture and explains how these should be taken into account in regulatory work, e.g. during safety assessment and regulatory inspection. The book also reflects how nuclear safety has been developed during the years on the basis of operating experience feedback and results of safety research by giving topical examples. The examples cover development of operating procedures and accident management to cope with complicated incidents and severe accidents to stress the importance of regulatory role in nuclear safety research. The main target group is new staff members of regulatory bodies, but the book also offers good examples for more experienced inspectors to be used as comparison and discussion basis in internal workshops organized by the regulatory bodies for refreshing and continuing training. The book was originally compiled on the basis of presentations provided during the two regulatory control training courses in 1997 and 1998. The textbook was reviewed at the beginning of the years 2000 and 2002 by IAEA staff members and consistency with the latest revisions of safety standards have been ensured. The textbook was completed in the

  14. Virtual grasping: closed-loop force control using electrotactile feedback.

    Science.gov (United States)

    Jorgovanovic, Nikola; Dosen, Strahinja; Djozic, Damir J; Krajoski, Goran; Farina, Dario

    2014-01-01

    Closing the control loop by providing somatosensory feedback to the user of a prosthesis is a well-known, long standing challenge in the field of prosthetics. Various approaches have been investigated for feedback restoration, ranging from direct neural stimulation to noninvasive sensory substitution methods. Although there are many studies presenting closed-loop systems, only a few of them objectively evaluated the closed-loop performance, mostly using vibrotactile stimulation. Importantly, the conclusions about the utility of the feedback were partly contradictory. The goal of the current study was to systematically investigate the capability of human subjects to control grasping force in closed loop using electrotactile feedback. We have developed a realistic experimental setup for virtual grasping, which operated in real time, included a set of real life objects, as well as a graphical and dynamical model of the prosthesis. We have used the setup to test 10 healthy, able bodied subjects to investigate the role of training, feedback and feedforward control, robustness of the closed loop, and the ability of the human subjects to generalize the control to previously "unseen" objects. Overall, the outcomes of this study are very optimistic with regard to the benefits of feedback and reveal various, practically relevant, aspects of closed-loop control.

  15. Virtual Grasping: Closed-Loop Force Control Using Electrotactile Feedback

    Directory of Open Access Journals (Sweden)

    Nikola Jorgovanovic

    2014-01-01

    Full Text Available Closing the control loop by providing somatosensory feedback to the user of a prosthesis is a well-known, long standing challenge in the field of prosthetics. Various approaches have been investigated for feedback restoration, ranging from direct neural stimulation to noninvasive sensory substitution methods. Although there are many studies presenting closed-loop systems, only a few of them objectively evaluated the closed-loop performance, mostly using vibrotactile stimulation. Importantly, the conclusions about the utility of the feedback were partly contradictory. The goal of the current study was to systematically investigate the capability of human subjects to control grasping force in closed loop using electrotactile feedback. We have developed a realistic experimental setup for virtual grasping, which operated in real time, included a set of real life objects, as well as a graphical and dynamical model of the prosthesis. We have used the setup to test 10 healthy, able bodied subjects to investigate the role of training, feedback and feedforward control, robustness of the closed loop, and the ability of the human subjects to generalize the control to previously “unseen” objects. Overall, the outcomes of this study are very optimistic with regard to the benefits of feedback and reveal various, practically relevant, aspects of closed-loop control.

  16. Regulatory control, legislation and framework

    International Nuclear Information System (INIS)

    Parthasarathy, K.S.

    1998-01-01

    The legislation and regulations, a regulatory authority to authorise and inspect the regulated activities and to enforce the legislation and regulations, sufficient financial and man-power resources are the essential parts of a national infrastructure to implement the Basic Safety Standards. The legal framework consists of legislation (Act passed by Parliament) and the regulations (framed by the government and endorsed by the Parliament). This paper is primarily deals with the the legal framework set up in India for atomic energy activities

  17. ac power control in the Core Flow Test Loop

    International Nuclear Information System (INIS)

    McDonald, D.W.

    1980-01-01

    This work represents a status report on a development effort to design an ac power controller for the Core Flow Test Loop. The Core Flow Test Loop will be an engineering test facility which will simulate the thermal environment of a gas-cooled fast-breeder reactor. The problems and limitations of using sinusoidal ac power to simulate the power generated within a nuclear reactor are addressed. The transformer-thyristor configuration chosen for the Core Flow Test Loop power supply is presented. The initial considerations, design, and analysis of a closed-loop controller prototype are detailed. The design is then analyzed for improved performance possibilities and failure modes are investigated at length. A summary of the work completed to date and a proposed outline for continued development completes the report

  18. Marine vehicle path following using inner-outer loop control.

    Digital Repository Service at National Institute of Oceanography (India)

    Maurya, P.K.; Agular, A.P.; Pascoal, A.M.

    constraints are imposed on the motion of the vehicle. This is in striking contrast with trajectory tracking, where the reference for the vehicle motion is given explicitly in terms of ”space versus time” coordinates. This strategy is seldom pursued in practice... that its output variables can be tracked infinitely fast by the inner dynamic loop. In practice, this does not hold true. Furthermore, many vehicle suppliers equip their platforms with inner dynamic control loops for which only a general characterization...

  19. Fuzzy logic controllers and chaotic natural convection loops

    International Nuclear Information System (INIS)

    Theler, German

    2007-01-01

    The study of natural circulation loops is a subject of special concern for the engineering design of advanced nuclear reactors, as natural convection provides an efficient and completely passive heat removal system. However, under certain circumstances thermal-fluid-dynamical instabilities may appear, threatening the reactor safety as a whole.On the other hand, fuzzy logic controllers provide an ideal framework to approach highly non-linear control problems. In the present work, we develop a software-based fuzzy logic controller and study its application to chaotic natural convection loops.We numerically analyse the linguistic control of the loop known as the Welander problem in such conditions that, if the controller were not present, the circulation flow would be non-periodic unstable.We also design a Taka gi-Sugeno fuzzy controller based on a fuzzy model of a natural convection loop with a toroidal geometry, in order to stabilize a Lorenz-chaotic behaviour.Finally, we show experimental results obtained in a rectangular natural circulation loop [es

  20. Closed-Loop and Robust Control of Quantum Systems

    Directory of Open Access Journals (Sweden)

    Chunlin Chen

    2013-01-01

    Full Text Available For most practical quantum control systems, it is important and difficult to attain robustness and reliability due to unavoidable uncertainties in the system dynamics or models. Three kinds of typical approaches (e.g., closed-loop learning control, feedback control, and robust control have been proved to be effective to solve these problems. This work presents a self-contained survey on the closed-loop and robust control of quantum systems, as well as a brief introduction to a selection of basic theories and methods in this research area, to provide interested readers with a general idea for further studies. In the area of closed-loop learning control of quantum systems, we survey and introduce such learning control methods as gradient-based methods, genetic algorithms (GA, and reinforcement learning (RL methods from a unified point of view of exploring the quantum control landscapes. For the feedback control approach, the paper surveys three control strategies including Lyapunov control, measurement-based control, and coherent-feedback control. Then such topics in the field of quantum robust control as H∞ control, sliding mode control, quantum risk-sensitive control, and quantum ensemble control are reviewed. The paper concludes with a perspective of future research directions that are likely to attract more attention.

  1. Closed-loop and robust control of quantum systems.

    Science.gov (United States)

    Chen, Chunlin; Wang, Lin-Cheng; Wang, Yuanlong

    2013-01-01

    For most practical quantum control systems, it is important and difficult to attain robustness and reliability due to unavoidable uncertainties in the system dynamics or models. Three kinds of typical approaches (e.g., closed-loop learning control, feedback control, and robust control) have been proved to be effective to solve these problems. This work presents a self-contained survey on the closed-loop and robust control of quantum systems, as well as a brief introduction to a selection of basic theories and methods in this research area, to provide interested readers with a general idea for further studies. In the area of closed-loop learning control of quantum systems, we survey and introduce such learning control methods as gradient-based methods, genetic algorithms (GA), and reinforcement learning (RL) methods from a unified point of view of exploring the quantum control landscapes. For the feedback control approach, the paper surveys three control strategies including Lyapunov control, measurement-based control, and coherent-feedback control. Then such topics in the field of quantum robust control as H(∞) control, sliding mode control, quantum risk-sensitive control, and quantum ensemble control are reviewed. The paper concludes with a perspective of future research directions that are likely to attract more attention.

  2. Two-loop feed water control system in BWR plants

    International Nuclear Information System (INIS)

    Omori, Takashi; Watanabe, Takao; Hirose, Masao.

    1982-01-01

    In the process of the start-up and shutdown of BWR plants, the operation of changing over feed pumps corresponding to plant output is performed. Therefore, it is necessary to develop the automatic changeover system for feed pumps, which minimizes the variation of water level in reactors and is easy to operate. The three-element control system with the water level in reactors, the flow rate of main steam and the flow rate of feed water as the input is mainly applied, but long time is required for the changeover of feed pumps. The two-loop feed control system can control simultaneously two pumps being changed over, therefore it is suitable to the automatic changeover control system for feed pumps. Also it is excellent for the control of the recirculating valves of feed pumps. The control characteristics of the two-loop feed water control system against the external disturbance which causes the variation of water level in reactors were examined. The results of analysis by simulation are reported. The features of the two-loop feed water control system, the method of simulation and the evaluation of the two-loop feed water control system are described. Its connection with a digital feed water recirculation control system is expected. (Kako, I.)

  3. ProMES: A method for "accepted control loops"

    NARCIS (Netherlands)

    Tuijl, van H.F.J.M.

    1997-01-01

    ProMES, a method for the measurement and feedback of performance data is related to the concepts of goal setting and feedback (Locke, 1991; Locke and Latham, 1990), and to the concept of self-control (Bandura, 1991). The result is a model for self-management: the "accepted control loop". Whether

  4. Speed Loop Control of PMSM Driving Electric Vehicle

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

    2011-01-01

    Various simulation models are set up and closed speed loop control strategy of PMSM is proposed based on flux weakening control in this paper. First the model of maximum torque per ampere(MTPA) is modeled based on mathematical models and gave the corresponding simulation tests. Second the formula...

  5. Closed-Loop Tension Control System for Injection Moulding Machine

    African Journals Online (AJOL)

    When the mould unit is full, this drive keeps transporting filament materials without proper control. This project developed a closed loop feedback tension control system and it is to replace servo motor drive system for the transportation of filament and it demonstrated a new technological advancement and the theory of ...

  6. Developments in the Control Loops Benchmarking

    OpenAIRE

    Bialic, Grzegorz; B??achuta, Marian B??

    2008-01-01

    In the chapter some developments in the control performance assessment are provided. The solution based on quadratic performance criteria which taking control effort into account was proposed in return for popular MV measure. This further broke about the definition of trade-off curve using standard deviation of both control and error signals. The standard deviation parameter is preferred because better than variance characterize the signal

  7. Nonlinear closed-loop control theory

    International Nuclear Information System (INIS)

    Perez, R.B.; Otaduy, P.J.; Abdalla, M.

    1992-01-01

    Traditionally, the control of nuclear power plants has been implemented by the use of proportional-integral (PI) control systems. PI controllers are both simple and, within their calibration range, highly reliable. However, PIs provide little performance information that could be used to diagnose out-of-range events or the nature of unanticipated transients that may occur in the plant. To go beyond the PI controller, the new control algorithms must deal with the physical system nonlinearities and with the reality of uncertain dynamics terms in its mathematical model. The tool to develop a new kind of control algorithm is provided by Optimal Control Theory. In this theory, a norm is minimized which incorporates the constraint that the model equations should be satisfied at all times by means of the Lagrange multipliers. Optimal control algorithms consist of two sets of coupled equations: (1) the model equations, integrated forward in time; and (2) the equations for the Lagrange multipliers (adjoints), integrated backwards in time. There are two challenges: dealing with large sets of coupled nonlinear equations and with a two-point boundary value problem that must be solved iteratively. In this paper, the rigorous conversion of the two-point boundary value problem into an initial value problem is presented. In addition, the incorporation into the control algorithm of ''real world'' constraints such as sensors and actuators, dynamic response functions and time lags introduced by the digitalization of analog signals is presented. (Author)

  8. Regulatory control of radiation sources in Slovakia

    International Nuclear Information System (INIS)

    Auxtova, L.

    2001-01-01

    In Slovakia, there are two regulatory authorities. Regulatory control of the utilization of nuclear energy, based on the Slovak National Council's law No. 130/1998 on the peaceful uses of nuclear energy, is exercised by the Nuclear Regulatory Authority of the Slovak Republic. The second regulatory authority - the Ministry of Health - is empowered by law No. 72/1994 on the protection of human health to license radiation sources and is responsible for radiation protection supervision (there are nearly 3000 establishments with sealed sources, radiation generators and unsealed sources in Slovakia). Pursuant to a new radiation protection regulation based on international standards, radiation sources are to be categorized in six classes according to the associated exposure and contamination hazards. A national strategy for improving the safety of radiation sources over their life-cycle and for the management of disused and orphan sources is being prepared for governmental approval. (author)

  9. Boosted PWM open loop control of hydraulic proportional valves

    International Nuclear Information System (INIS)

    Amirante, R.; Innone, A.; Catalano, L.A.

    2008-01-01

    This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots

  10. Boosted PWM open loop control of hydraulic proportional valves

    Energy Technology Data Exchange (ETDEWEB)

    Amirante, R.; Catalano, L.A. [Dipartimento di Ingegneria Meccanica e Gestionale, Politecnico di Bari, Via Re David 200, 70125 Bari (Italy); Innone, A. [Universita degli Studi di Foggia, via Napoli, 25 Foggia (Italy)

    2008-08-15

    This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots. (author)

  11. Simulation of closed loop controlled boost converter for solar installation

    Directory of Open Access Journals (Sweden)

    Kalirasu Athimulam

    2010-01-01

    Full Text Available With the shortage of the energy and ever increasing of the oil price, research on the renewable and green energy sources, especially the solar arrays and the fuel cells, becomes more and more important. How to achieve high stepup and high efficiency DC/DC converters is the major consideration in the renewable power applications due to the low voltage of PV arrays and fuel cells. In this paper digital simulation of closed loop controlled boost converter for solar installation is presented. Circuit models for open loop and closed loop controlled systems are developed using the blocks of simulink. The simulation results are compared with the theoretical results. This converter has advantages like improved power factor, fast response and reduced hardware. .

  12. Error analysis of acceleration control loops of a synchrotron

    International Nuclear Information System (INIS)

    Zhang, S.Y.; Weng, W.T.

    1991-01-01

    For beam control during acceleration, it is conventional to derive the frequency from an external reference, be it a field marker or an external oscillator, to provide phase and radius feedback loops to ensure the phase stability, radial position and emittance integrity of the beam. The open and closed loop behaviors of both feedback control and their response under the possible frequency, phase and radius errors are derived from fundamental principles and equations. The stability of the loops is investigated under a wide range of variations of the gain and time delays. Actual system performance of the AGS Booster is analyzed and compared to commissioning experiences. Such analysis is useful for setting design criteria and tolerances for new proton synchrotrons. 4 refs., 13 figs

  13. Regulatory Control of Radioactive Sources in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M.; Martin, J.L., E-mail: mrm@csn.es [Nuclear Safety Council, Madrid (Spain)

    2011-07-15

    The arrangements for the regulatory control of the safety and security of sealed radioactive sources in Spain are described. Emphasis is given to the situations which are most likely to result in the loss of control of sources and on the procedures introduced to reduce the likelihood of losses in these cases. Finally, the strategy for locating sources which have been lost from control (orphan sources) is described. (author)

  14. Ammonia sensor for closed-loop SCR control

    NARCIS (Netherlands)

    Wang, D.Y.; Yao, S.; Shost, M.; Yoo, J.H.; Cabush, D.; Racine, D.; Cloudt, R.P.M.; Willems, F.P.T.

    2009-01-01

    Selective Catalytic Reduction (SCR) is the dominant solution for meeting future NOx reduction regulations for heavy-duty diesel powertrains. SCR systems benefit from closed-loop control if an appropriate exhaust gas sensor were available. An ammonia sensor has recently been developed for use as a

  15. An Architectural Style for Closed-loop Process-Control

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Eriksen, Ole

    2003-01-01

    This report describes an architectural style for distributed closed-loop process control systems with high performance and hard real-time constraints. The style strikes a good balance between the architectural qualities of performance and modifiability/maintainability that traditionally are often...

  16. An Architectural Style for Closed-loop Process-Control

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    This report describes an architectural style for distributed closed-loop process control systems with high performance and hard real-time constraints. The style strikes a good balance between the architectural qualities of performance and modifiability/maintainability that traditionally are often...

  17. Ammonia sensor for closed-loop SCR control

    NARCIS (Netherlands)

    Wang, D.Y.; Yao, S.; Shost, M.; Yoo, J.H.; Cabush, D.; Racine, D.; Cloudt, R.P.M.; Willems, F.P.T.

    2008-01-01

    Selective Catalytic Reduction (SCR) is the dominant solution for meeting future NOx reduction regulations for heavy-duty diesel powertrains. SCR systems benefit from closed-loop control if an appropriate exhaust gas sensor were available. An ammonia sensor has recently been developed for use as a

  18. Regulatory BC1 RNA in Cognitive Control

    Science.gov (United States)

    Iacoangeli, Anna; Dosunmu, Aderemi; Eom, Taesun; Stefanov, Dimitre G.; Tiedge, Henri

    2017-01-01

    Dendritic regulatory BC1 RNA is a non-protein-coding (npc) RNA that operates in the translational control of gene expression. The absence of BC1 RNA in BC1 knockout (KO) animals causes translational dysregulation that entails neuronal phenotypic alterations including prolonged epileptiform discharges, audiogenic seizure activity in vivo, and…

  19. P53-miR-191-SOX4 regulatory loop affects apoptosis in breast cancer.

    Science.gov (United States)

    Sharma, Shivani; Nagpal, Neha; Ghosh, Prahlad C; Kulshreshtha, Ritu

    2017-08-01

    miRNAs have emerged as key participants of p53 signaling pathways because they regulate or are regulated by p53. Here, we provide the first study demonstrating direct regulation of an oncogenic miRNA, miR-191-5p, by p53 and existence of a regulatory feedback loop. Using a combination of qRT-PCR, promoter-luciferase, and chromatin-immunoprecipitation assays, we show that p53 brings about down-regulation of miR-191-5p in breast cancer. miR-191-5p overexpression brought about inhibition of apoptosis in breast cancer cell lines (MCF7 and ZR-75) as demonstrated by reduction in annexin-V stained cells and caspase 3/7 activity, whereas miR-191-5p down-regulation showed the opposite. We further unveiled that SOX4 was a direct target of miR-191-5p. SOX4 overexpression was shown to increase p53 protein levels in MCF7 cells. miR-191-5p overexpression brought about down-regulation of SOX4 and thus p53 levels, suggesting the existence of a regulatory feedback loop. Breast cancer treatment by doxorubicin, an anti-cancer drug, involves induction of apoptosis by p53; we thus wanted to check whether miR-191-5p affects doxorubicin sensitivity. Interestingly, Anti-miR-191 treatment significantly decreased the IC50 of the doxorubicin drug and thus sensitized breast cancer cells to doxorubicin treatment by promoting apoptosis. Overall, this work highlights the importance of the p53-miR-191- SOX4 axis in the regulation of apoptosis and drug resistance in breast cancer and offers a preclinical proof-of-concept for use of an Anti-miR-191 and doxorubicin combination as a rational approach to pursue for better breast cancer treatment. © 2017 Sharma et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  20. Closed-loop waveform control of boost inverter

    DEFF Research Database (Denmark)

    Zhu, Guo Rong; Xiao, Cheng Yuan; Wang, Haoran

    2016-01-01

    The input current of single-phase inverter typically has an AC ripple component at twice the output frequency, which causes a reduction in both the operating lifetime of its DC source and the efficiency of the system. In this paper, the closed-loop performance of a proposed waveform control method...... to eliminate such a ripple current in boost inverter is investigated. The small-signal stability and the dynamic characteristic of the inverter system for input voltage or wide range load variations under the closed-loop waveform control method are studied. It is validated that with the closedloop waveform...... control, not only was stability achieved, the reference voltage of the boost inverter capacitors can be instantaneously adjusted to match the new load, thereby achieving improved ripple mitigation for a wide load range. Furthermore, with the control and feedback mechanism, there is minimal level of ripple...

  1. Regulatory aspects of criticality control in Australia

    International Nuclear Information System (INIS)

    Zimin, Sergei

    2003-01-01

    With the creation of Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) the Australian approach to criticality safety was revisited. Consistency with international best practices is required by the Act that created ARPANSA and this was applied to practices in criticality safety adopted in other countries. This required extensive regulatory efforts both in auditing the major Australian Nuclear Operator, Australian Nuclear Science and Technology Organisation (ANSTO), and assessing the existing in Australia criticality safety practices and implementing the required changes using the new legislative power of ARPANSA. The adopted regulatory approach is formulated through both the issued by ARPANSA licenses for nuclear installations (including reactors, fuel stores and radioactive waste stores) and the string of new regulatory documents, including the Regulatory Assessment Principles and the Regulatory Assessment Guidelines for criticality safety. The main features of the adopted regulation include the requirements of independent peer-review, ongoing refresher training coupled with annual accreditation and the reliance on the safe design rather than on an administrative control. (author)

  2. Closed-Loop Optimal Control Implementations for Space Applications

    Science.gov (United States)

    2016-12-01

    with standard linear algebra techniques if is converted to a diagonal square matrix by multiplying by the identity matrix, I , as was done in (1.134...OPTIMAL CONTROL IMPLEMENTATIONS FOR SPACE APPLICATIONS by Colin S. Monk December 2016 Thesis Advisor: Mark Karpenko Second Reader: I. M...COVERED Master’s thesis, Jan-Dec 2016 4. TITLE AND SUBTITLE CLOSED-LOOP OPTIMAL CONTROL IMPLEMENTATIONS FOR SPACE APPLICATIONS 5. FUNDING NUMBERS

  3. A complete closed loop control system for MNSR

    International Nuclear Information System (INIS)

    Wang Liyu

    1988-01-01

    The MNSR (Miniature Neutron Source Reactor), a 27 kW reactor, was built in 1984 in the Institute of Atomic Energy, Beijing, China. A microcomputer closed-loop control system has been developed for the MNSR using an IBM PC-XT. This system not only controls the reactor, but it is also a data acquisition system and a reactivity monitor for the reactor. A closed-loop control system can be used for reactors such as the MNSR, in which the power is self-limited and the reactivity is limited to less than 5mk (∼0.7$). As a data acquisition system or a reactivity monitor, it is applicable for any nuclear reactor. This paper describes the hardware and software in detail. 4 refs, 11 figs

  4. Thrust Control Loop Design for Electric-Powered UAV

    Science.gov (United States)

    Byun, Heejae; Park, Sanghyuk

    2018-04-01

    This paper describes a process of designing a thrust control loop for an electric-powered fixed-wing unmanned aerial vehicle equipped with a propeller and a motor. In particular, the modeling method of the thrust system for thrust control is described in detail and the propeller thrust and torque force are modeled using blade element theory. A relation between current and torque of the motor is obtained using an experimental setup. Another relation between current, voltage and angular velocity is also obtained. The electric motor and the propeller dynamics are combined to model the thrust dynamics. The associated trim and linearization equations are derived. Then, the thrust dynamics are coupled with the flight dynamics to allow a proper design for the thrust loop in the flight control. The proposed method is validated by an application to a testbed UAV through simulations and flight test.

  5. Eco-efficiency and control loop configuration for recycle systems

    Energy Technology Data Exchange (ETDEWEB)

    Munir, Muhammad Tajammal; Yu, Wei; Young, Brent P. [The University of Auckland, Auckland (New Zealand)

    2013-05-15

    To integrate measurements of eco-efficiency with control loop configuration has become an important topic since all industrial processes/plants are requested to increase their eco-efficiency. The exergy eco-efficiency factor, a new measure of eco-efficiency for control loop configuration, has been developed recently. The exergy eco-efficiency factor is based on the thermodynamic concept of exergy, which can be used to analyze a process in terms of its efficiency. The combination of the relative gain array (RGA), NI, CN, dynamic RGA, and the exergy eco-efficiency factor will help guide the process designer to find the optimal control design with low operating cost/eco-efficiency. In this paper, we validate the proposed exergy eco-efficiency factor for processes with recycles which are very common industrially.

  6. Eco-efficiency and control loop configuration for recycle systems

    International Nuclear Information System (INIS)

    Munir, Muhammad Tajammal; Yu, Wei; Young, Brent P.

    2013-01-01

    To integrate measurements of eco-efficiency with control loop configuration has become an important topic since all industrial processes/plants are requested to increase their eco-efficiency. The exergy eco-efficiency factor, a new measure of eco-efficiency for control loop configuration, has been developed recently. The exergy eco-efficiency factor is based on the thermodynamic concept of exergy, which can be used to analyze a process in terms of its efficiency. The combination of the relative gain array (RGA), NI, CN, dynamic RGA, and the exergy eco-efficiency factor will help guide the process designer to find the optimal control design with low operating cost/eco-efficiency. In this paper, we validate the proposed exergy eco-efficiency factor for processes with recycles which are very common industrially

  7. Oncogenic MYC Activates a Feedforward Regulatory Loop Promoting Essential Amino Acid Metabolism and Tumorigenesis.

    Science.gov (United States)

    Yue, Ming; Jiang, Jue; Gao, Peng; Liu, Hudan; Qing, Guoliang

    2017-12-26

    Most tumor cells exhibit obligatory demands for essential amino acids (EAAs), but the regulatory mechanisms whereby tumor cells take up EAAs and EAAs promote malignant transformation remain to be determined. Here, we show that oncogenic MYC, solute carrier family (SLC) 7 member 5 (SLC7A5), and SLC43A1 constitute a feedforward activation loop to promote EAA transport and tumorigenesis. MYC selectively activates Slc7a5 and Slc43a1 transcription through direct binding to specific E box elements within both genes, enabling effective EAA import. Elevated EAAs, in turn, stimulate Myc mRNA translation, in part through attenuation of the GCN2-eIF2α-ATF4 amino acid stress response pathway, leading to MYC-dependent transcriptional amplification. SLC7A5/SLC43A1 depletion inhibits MYC expression, metabolic reprogramming, and tumor cell growth in vitro and in vivo. These findings thus reveal a MYC-SLC7A5/SLC43A1 signaling circuit that underlies EAA metabolism, MYC deregulation, and tumorigenesis. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. miR-137 forms a regulatory loop with nuclear receptor TLX and LSD1 in neural stem cells.

    Science.gov (United States)

    Sun, GuoQiang; Ye, Peng; Murai, Kiyohito; Lang, Ming-Fei; Li, Shengxiu; Zhang, Heying; Li, Wendong; Fu, Chelsea; Yin, Jason; Wang, Allen; Ma, Xiaoxiao; Shi, Yanhong

    2011-11-08

    miR-137 is a brain-enriched microRNA. Its role in neural development remains unknown. Here we show that miR-137 has an essential role in controlling embryonic neural stem cell fate determination. miR-137 negatively regulates cell proliferation and accelerates neural differentiation of embryonic neural stem cells. In addition, we show that the histone lysine-specific demethylase 1 (LSD1), a transcriptional co-repressor of nuclear receptor TLX, is a downstream target of miR-137. In utero electroporation of miR-137 in embryonic mouse brains led to premature differentiation and outward migration of the transfected cells. Introducing a LSD1 expression vector lacking the miR-137 recognition site rescued miR-137-induced precocious differentiation. Furthermore, we demonstrate that TLX, an essential regulator of neural stem cell self-renewal, represses the expression of miR-137 by recruiting LSD1 to the genomic regions of miR-137. Thus, miR-137 forms a feedback regulatory loop with TLX and LSD1 to control the dynamics between neural stem cell proliferation and differentiation during neural development.

  9. Joint angle sensors for closed-loop control

    Science.gov (United States)

    Ko, Wen H.; Miao, Chih-Lei

    In order to substitute braces that have built-in goniometers and to provide feedback signals for closed loop control of lower extremity Functional Neuromuscular System in paraplegics, a stretchable capacitive sensor was developed to accurately detect angular movement in joints. Promising clinical evaluations on the knee joints of a paraplegic and a volunteer were done. The evaluations show great promise for the possibility of implantation applications.

  10. The plant cytoskeleton controls regulatory volume increase.

    Science.gov (United States)

    Liu, Qiong; Qiao, Fei; Ismail, Ahmed; Chang, Xiaoli; Nick, Peter

    2013-09-01

    The ability to adjust cell volume is required for the adaptation to osmotic stress. Plant protoplasts can swell within seconds in response to hypoosmotic shock suggesting that membrane material is released from internal stores. Since the stability of plant membranes depends on submembraneous actin, we asked, whether this regulatory volume control depends on the cytoskeleton. As system we used two cell lines from grapevine which differ in their osmotic tolerance and observed that the cytoskeleton responded differently in these two cell lines. To quantify the ability for regulatory volume control, we used hydraulic conductivity (Lp) as readout and demonstrated a role of the cytoskeleton in protoplast swelling. Chelation of calcium, inhibition of calcium channels, or manipulation of membrane fluidity, did not significantly alter Lp, whereas direct manipulation of the cytoskeleton via specific chemical reagents, or indirectly, through the bacterial elicitor Harpin or activation of phospholipase D, was effective. By optochemical engineering of actin using a caged form of the phytohormone auxin we can break the symmetry of actin organisation resulting in a localised deformation of cell shape indicative of a locally increased Lp. We interpret our findings in terms of a model, where the submembraneous cytoskeleton controls the release of intracellular membrane stores during regulatory volume change. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Photoacoustic-Based-Close-Loop Temperature Control for Nanoparticle Hyperthermia.

    Science.gov (United States)

    Xiaohua, Feng; Fei, Gao; Yuanjin, Zheng

    2015-07-01

    Hyperthermia therapy requires tight temperature control to achieve selective killing of cancerous tissue with minimal damage on surrounding healthy tissues. To this end, accurate temperature monitoring and subsequent heating control are critical. However, an economic, portable, and real-time temperature control solution is currently lacking. To bridge this gap, we present a novel portable close-loop system for hyperthermia temperature control, in which photoacoustic technique is proposed for noninvasive real-time temperature measurement. Exploiting the high sensitivity of photoacoustics, the temperature is monitored with an accuracy of around 0.18 °C and then fed back to a controller implemented on field programmable gate array (FPGA) for temperature control. Dubbed as portable hyperthermia feedback controller (pHFC), it stabilizes the temperature at preset values by regulating the hyperthermia power with a proportional-integral-derivative (PID) algorithm; and to facilitate digital implementation, the pHFC further converts the PID output into switching values (0 and 1) with the pulse width modulation (PWM) algorithm. Proof-of-concept hyperthermia experiments demonstrate that the pHFC system is able to bring the temperature from baseline to predetermined value with an accuracy of 0.3° and a negligible temperature overshoot. The pHFC can potentially be translated to clinical applications with customized hyperthermia system design. This paper can facilitate future efforts in seamless integration of close-loop temperature control solution and various clinical hyperthermia systems.

  12. A feedback regulatory loop involving microRNA-9 and nuclear receptor TLX in neural stem cell fate determination.

    Science.gov (United States)

    Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Shi, Yanhong

    2009-04-01

    MicroRNAs have been implicated as having important roles in stem cell biology. MicroRNA-9 (miR-9) is expressed specifically in neurogenic areas of the brain and may be involved in neural stem cell self-renewal and differentiation. We showed previously that the nuclear receptor TLX is an essential regulator of neural stem cell self-renewal. Here we show that miR-9 suppresses TLX expression to negatively regulate neural stem cell proliferation and accelerate neural differentiation. Introducing a TLX expression vector that is not prone to miR-9 regulation rescued miR-9-induced proliferation deficiency and inhibited precocious differentiation. In utero electroporation of miR-9 in embryonic brains led to premature differentiation and outward migration of the transfected neural stem cells. Moreover, TLX represses expression of the miR-9 pri-miRNA. By forming a negative regulatory loop with TLX, miR-9 provides a model for controlling the balance between neural stem cell proliferation and differentiation.

  13. Reconstruction and analysis of transcription factor-miRNA co-regulatory feed-forward loops in human cancers using filter-wrapper feature selection.

    Directory of Open Access Journals (Sweden)

    Chen Peng

    Full Text Available BACKGROUND: As one of the most common types of co-regulatory motifs, feed-forward loops (FFLs control many cell functions and play an important role in human cancers. Therefore, it is crucial to reconstruct and analyze cancer-related FFLs that are controlled by transcription factor (TF and microRNA (miRNA simultaneously, in order to find out how miRNAs and TFs cooperate with each other in cancer cells and how they contribute to carcinogenesis. Current FFL studies rely on predicted regulation information and therefore suffer the false positive issue in prediction results. More critically, FFLs generated by existing approaches cannot represent the dynamic and conditional regulation relationship under different experimental conditions. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we proposed a novel filter-wrapper feature selection method to accurately identify co-regulatory mechanism by incorporating prior information from predicted regulatory interactions with parallel miRNA/mRNA expression datasets. By applying this method, we reconstructed 208 and 110 TF-miRNA co-regulatory FFLs from human pan-cancer and prostate datasets, respectively. Further analysis of these cancer-related FFLs showed that the top-ranking TF STAT3 and miRNA hsa-let-7e are key regulators implicated in human cancers, which have regulated targets significantly enriched in cellular process regulations and signaling pathways that are involved in carcinogenesis. CONCLUSIONS/SIGNIFICANCE: In this study, we introduced an efficient computational approach to reconstruct co-regulatory FFLs by accurately identifying gene co-regulatory interactions. The strength of the proposed feature selection method lies in the fact it can precisely filter out false positives in predicted regulatory interactions by quantitatively modeling the complex co-regulation of target genes mediated by TFs and miRNAs simultaneously. Moreover, the proposed feature selection method can be generally applied to

  14. Retrospective Cost Adaptive Control with Concurrent Closed-Loop Identification

    Science.gov (United States)

    Sobolic, Frantisek M.

    Retrospective cost adaptive control (RCAC) is a discrete-time direct adaptive control algorithm for stabilization, command following, and disturbance rejection. RCAC is known to work on systems given minimal modeling information which is the leading numerator coefficient and any nonminimum-phase (NMP) zeros of the plant transfer function. This information is normally needed a priori and is key in the development of the filter, also known as the target model, within the retrospective performance variable. A novel approach to alleviate the need for prior modeling of both the leading coefficient of the plant transfer function as well as any NMP zeros is developed. The extension to the RCAC algorithm is the use of concurrent optimization of both the target model and the controller coefficients. Concurrent optimization of the target model and controller coefficients is a quadratic optimization problem in the target model and controller coefficients separately. However, this optimization problem is not convex as a joint function of both variables, and therefore nonconvex optimization methods are needed. Finally, insights within RCAC that include intercalated injection between the controller numerator and the denominator, unveil the workings of RCAC fitting a specific closed-loop transfer function to the target model. We exploit this interpretation by investigating several closed-loop identification architectures in order to extract this information for use in the target model.

  15. Close-loop Dynamic Stall Control on a Pitching Airfoil

    Science.gov (United States)

    Giles, Ian; Corke, Thomas

    2017-11-01

    A closed-loop control scheme utilizing a plasma actuator to control dynamic stall is presented. The plasma actuator is located at the leading-edge of a pitching airfoil. It initially pulses at an unsteady frequency that perturbs the boundary layer flow over the suction surface of the airfoil. As the airfoil approaches and enters stall, the amplification of the unsteady disturbance is detected by an onboard pressure sensor also located near the leading edge. Once detected, the actuator is switched to a higher voltage control state that in static airfoil experiments would reattach the flow. The threshold level of the detection is a parameter in the control scheme. Three stall regimes were examined: light, medium, and deep stall, that were defined by their stall penetration angles. The results showed that in general, the closed-loop control scheme was effective at controlling dynamic stall. The cycle-integrated lift improved in all cases, and increased by as much as 15% at the lowest stall penetration angle. As important, the cycle-integrated aerodynamic damping coefficient also increased in all cases, and was made to be positive at the light stall regime where it traditionally is negative. The latter is important in applications where negative damping can lead to stall flutter.

  16. Pulse energy control through dual loop electronic feedback

    CSIR Research Space (South Africa)

    Jacobs, Cobus

    2006-07-01

    Full Text Available University of Stellenbosch WWW.LASER-RESEARCH.CO.ZA University of Stellenbosch Pulse Energy Control Through Dual Loop Electronic Feedback Cobus Jacobs, Steven Kriel Christoph Bollig, Thomas Jones Cobus Jacobs et al. Overview head2righthead2right...What is Laser Pulse Energy Control? head2righthead2rightWhy do we need it? head2righthead2rightHow do we get it? head2righthead2rightSimulation head2righthead2rightExperimental Setup head2righthead2rightResults Cobus Jacobs et al. head2righthead2right...

  17. Numerical investigation of closed-loop control for Hall accelerators

    International Nuclear Information System (INIS)

    Barral, S.; Miedzik, J.

    2011-01-01

    Low frequency discharge current oscillations in Hall accelerators are conventionally damped with external inductor-capacitor (LC) or resistor-inductor-capacitor (RLC) networks. The role of such network in the stabilization of the plasma discharge is investigated with a numerical model and the potential advantages of proportional-integral-derivative (PID) closed-loop control over RLC networks are subsequently assessed using either discharge voltage or magnetic field modulation. Simulations confirm the reduction of current oscillations in the presence of a RLC network, but suggest that PID control could ensure nearly oscillation-free operation with little sensitivity toward the PID settings.

  18. Practical Loop-Shaping Design of Feedback Control Systems

    Science.gov (United States)

    Kopasakis, George

    2010-01-01

    An improved methodology for designing feedback control systems has been developed based on systematically shaping the loop gain of the system to meet performance requirements such as stability margins, disturbance attenuation, and transient response, while taking into account the actuation system limitations such as actuation rates and range. Loop-shaping for controls design is not new, but past techniques do not directly address how to systematically design the controller to maximize its performance. As a result, classical feedback control systems are designed predominantly using ad hoc control design approaches such as proportional integral derivative (PID), normally satisfied when a workable solution is achieved, without a good understanding of how to maximize the effectiveness of the control design in terms of competing performance requirements, in relation to the limitations of the plant design. The conception of this improved methodology was motivated by challenges in designing control systems of the types needed for supersonic propulsion. But the methodology is generally applicable to any classical control-system design where the transfer function of the plant is known or can be evaluated. In the case of a supersonic aerospace vehicle, a major challenge is to design the system to attenuate anticipated external and internal disturbances, using such actuators as fuel injectors and valves, bypass doors, and ramps, all of which are subject to limitations in actuator response, rates, and ranges. Also, for supersonic vehicles, with long slim type of structures, coupling between the engine and the structural dynamics can produce undesirable effects that could adversely affect vehicle stability and ride quality. In order to design distributed controls that can suppress these potential adverse effects, within the full capabilities of the actuation system, it is important to employ a systematic control design methodology such as this that can maximize the

  19. Closed loop kinesthetic feedback for postural control rehabilitation.

    Science.gov (United States)

    Vérité, Fabien; Bachta, Wael; Morel, Guillaume

    2014-01-01

    Postural control rehabilitation may benefit from the use of smart devices providing biofeedback. This approach consists of increasing the patients perception of their postural state. Namely, postural state is monitored and fed back in real time to the patients through one or more sensory channels. This allows implementing rehabilitation exercises where the patients control their posture with the help of additional sensory inputs. In this paper, a closed loop control of the Center-Of-Pressure (CoP) based on kinesthetic feedback is proposed as a new form of biofeedback. The motion of a one Degree of Freedom (DoF) translational device, lightly touched by the patient's forefinger, is servoed to the patient's CoP position extracted from the measurements of a force plate on which he/she stands. As a result, the patient's CoP can be controllably displaced. A first set of experiments is used to prove the feasibility of this closed-loop control under ideal conditions favoring the perception of the kinesthetic feedback, while the subject is totally unaware of the context. A second set of experiments is then proposed to evaluate the robustness of this approach under experimental conditions that are more realistic with regards to the clinical context of a rehabilitation program involving biofeedback-based exercises.

  20. Regulatory control of radiation sources in Germany

    International Nuclear Information System (INIS)

    Coy, K.

    1998-01-01

    The regulatory programme governing the safe use of radioisotopes in Germany is based on the federal legislation enacted as Atomic Energy Control Act (Atomgesetz) and Radiation Protection Ordinance (Strahlen-schutzverordnung) and its implementation by the competent authorities of the individual states. Despite this highly decentralized infrastructure of enforcement the basic principles of regulations described in this paper such as authorization criteria, conditions imposed as well as depth and intensity of inspection balanced according to the individual radiation hazard involved are harmonized to the greatest possible extent by regular coordination among the competent authorities as well as a series of technical regulations such as standards and guidelines. (author)

  1. Delivering precision antimicrobial therapy through closed-loop control systems

    Science.gov (United States)

    Rawson, T M; O’Hare, D; Herrero, P; Sharma, S; Moore, L S P; de Barra, E; Roberts, J A; Gordon, A C; Hope, W; Georgiou, P; Cass, A E G; Holmes, A H

    2018-01-01

    Abstract Sub-optimal exposure to antimicrobial therapy is associated with poor patient outcomes and the development of antimicrobial resistance. Mechanisms for optimizing the concentration of a drug within the individual patient are under development. However, several barriers remain in realizing true individualization of therapy. These include problems with plasma drug sampling, availability of appropriate assays, and current mechanisms for dose adjustment. Biosensor technology offers a means of providing real-time monitoring of antimicrobials in a minimally invasive fashion. We report the potential for using microneedle biosensor technology as part of closed-loop control systems for the optimization of antimicrobial therapy in individual patients. PMID:29211877

  2. Control Performance Management in Industrial Automation Assessment, Diagnosis and Improvement of Control Loop Performance

    CERN Document Server

    Jelali, Mohieddine

    2013-01-01

    Control Performance Management in Industrial Automation provides a coherent and self-contained treatment of a group of methods and applications of burgeoning importance to the detection and solution of problems with control loops that are vital in maintaining product quality, operational safety, and efficiency of material and energy consumption in the process industries. The monograph deals with all aspects of control performance management (CPM), from controller assessment (minimum-variance-control-based and advanced methods), to detection and diagnosis of control loop problems (process non-linearities, oscillations, actuator faults), to the improvement of control performance (maintenance, re-design of loop components, automatic controller re-tuning). It provides a contribution towards the development and application of completely self-contained and automatic methodologies in the field. Moreover, within this work, many CPM tools have been developed that goes far beyond available CPM packages. Control Perform...

  3. Open-loop control of quasiperiodic thermoacoustic oscillations

    Science.gov (United States)

    Guan, Yu; Gupta, Vikrant; Kashinath, Karthik; Li, Larry K. B.

    2017-11-01

    The open-loop application of periodic acoustic forcing has been shown to be a potentially effective strategy for controlling periodic thermoacoustic oscillations, but its effectiveness on aperiodic thermoacoustic oscillations is less clear. In this experimental study, we apply periodic acoustic forcing to a ducted premixed flame oscillating quasiperiodically at two incommensurate natural frequencies, f1 and f2. We find that (i) above a critical forcing amplitude, the system locks into the forcing by oscillating only at the forcing frequency ff, producing a closed periodic orbit in phase space with no evidence of the original T2 torus attractor; (ii) the critical forcing amplitude required for lock-in decreases as ff approaches either f1 or f2, resulting in characteristic ∨-shaped lock-in boundaries around the two natural modes; and (iii) for a wide range of forcing frequencies, the system's oscillation amplitude can be reduced to less than 20% of that of the unforced system. These findings show that the open-loop application of periodic acoustic forcing can be an effective strategy for controlling aperiodic thermoacoustic oscillations. This work was supported by the Research Grants Council of Hong Kong (Project No. 16235716 and 26202815).

  4. Closed Loop Control Compact Exercise Device for Use on MPCV

    Science.gov (United States)

    Sheehan, Chris; Funk, Justin; Funk, Nathan; Kutnick, Gilead; Humphreys, Brad; Bruinsma, Douwe; Perusek, Gail

    2016-01-01

    Long duration space travel to Mars or to an asteroid will expose astronauts to extended periods of reduced gravity. To combat spaceflight physiological deconditioning, astronauts will use resistive and aerobic exercise regimens for the duration of the space flight to minimize the loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the mass and volume available for an exercise device in the next generation of spacecraft is limited. Therefore, compact exercise device prototypes are being developed for human in the loop evaluations. The NASA Human Research Program (HRP) is managing Advanced Exercise Concepts (AEC) requirements development and candidate technology maturation for all exploration mission profiles from Multi-Purpose Crew Vehicle (MPCV) exploration missions (e.g., EM-2, up to 21 day) to Mars Transit (up to 1000 day) missions. Numerous technologies have been considered and evaluated against HRP-approved functional requirements and include flywheel, pneumatic and closed-loop microprocessor-controlled motor driven power plants. Motor driven technologies offer excellent torque density and load accuracy characteristics as well as the ability to create custom mechanical impedance (the dynamic relationship between force and velocity) and custom load versus position exercise algorithms. Further, closed-loop motor-driven technologies offer the ability to monitor exercise dose parameters and adapt to the needs of the crewmember for real time optimization of exercise prescriptions. A simple proportional-integral-derivative (PID) controller is demonstrated in a prototype motor driven exercise device with comparison to resistive static and dynamic load set points and aerobic work rate targets. The resistive load term in the algorithm includes a constant force component (Fcmg) as well as inertial component (Fima) and a discussion of system tuning is presented

  5. Regulatory Control of Radiation Sources. Safety Guide (Arabic Edition)

    International Nuclear Information System (INIS)

    2012-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  6. Implementation of Close Loop Speed Control with VVVF Control and Slip Regulation on LIM

    Directory of Open Access Journals (Sweden)

    K. Aditya

    2014-04-01

    Full Text Available Open loop VVVF control has the disadvantage of low output torque when working at low frequency and poor speed precision at different load conditions.Various performance-improving schemes have been proposed for the basic VVVF control by compensating slips occurring in the low frequency range and slips caused by changing loads. Numerous papers have been published on the close loop speed control of rotary induction motor. In this paper a close loop speed control with VVVF control and slip regulation has been implemented for LIM based conveyor belt test Rig which compensates the disadvantages of traditional Volts/Hz control. SIMULINK results are presented to validate the effectiveness of proposed scheme.

  7. Commissioning of closed loop controls at CPP, HWP, Manuguru (Paper No. 3.5)

    International Nuclear Information System (INIS)

    Basu, Sukumar; Narasimham, P.L.

    1992-01-01

    The captive power plant (CPP) for Heavy Water Plant, Manuguru is equipped with 3x265 T/hr steam capacity boilers. The control system is built around ASEA master hardware for sequence interlocks, closed loop control, and data acquisition functions. This paper describes the configuration of the system hardware, the steps carried out during commissioning of closed loop controls in distributed digital control systems and also the problems faced during the commissioning of closed loops. (author). 3 figs

  8. Control Strategies for Islanded Microgrid using Enhanced Hierarchical Control Structure with Multiple Current-Loop Damping Schemes

    DEFF Research Database (Denmark)

    Han, Yang; Shen, Pan; Zhao, Xin

    2017-01-01

    In this paper, the modeling, controller design, and stability analysis of the islanded microgrid (MG) using enhanced hierarchical control structure with multiple current loop damping schemes is proposed. The islanded MG is consisted of the parallel-connected voltage source inverters using LCL...... output filters, and the proposed control structure includes: the primary control with additional phase-shift loop, the secondary control for voltage amplitude and frequency restoration, the virtual impedance loops which contains virtual positive- and negative-sequence impedance loops at fundamental...... frequency, and virtual variable harmonic impedance loop at harmonic frequencies, and the inner voltage and current loop controllers. A small-signal model for the primary and secondary controls with additional phase-shift loop is presented, which shows an over-damped feature from eigenvalue analysis...

  9. An optimal open/closed-loop control method with application to a pre-stressed thin duralumin plate

    Science.gov (United States)

    Nadimpalli, Sruthi Raju

    The excessive vibrations of a pre-stressed duralumin plate, suppressed by a combination of open-loop and closed-loop controls, also known as open/closed-loop control, is studied in this thesis. The two primary steps involved in this process are: Step (I) with an assumption that the closed-loop control law is proportional, obtain the optimal open-loop control by direct minimization of the performance measure consisting of energy at terminal time and a penalty on open-loop control force via calculus of variations. If the performance measure also involves a penalty on closed-loop control effort then a Fourier based method is utilized. Step (II) the energy at terminal time is minimized numerically to obtain optimal values of feedback gains. The optimal closed-loop control gains obtained are used to describe the displacement and the velocity of open-loop, closed-loop and open/closed-loop controlled duralumin plate.

  10. A low power automatic gain control loop for a receiver

    Energy Technology Data Exchange (ETDEWEB)

    Li Guofeng; Geng Zhiqing; Wu Nanjian, E-mail: nanjian@red.semi.ac.c [State Key Laboratory for Super lattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2010-09-15

    This paper proposes a new structure to lower the power consumption of a variable gain amplifier (VGA) and keep the linearity of the VGA unchanged. The structure is used in a high rate amplitude-shift keying (ASK) based IF-stage. It includes an automatic gain control (AGC) loop and ASK demodulator. The AGC mainly consists of six-stage VGAs. The IF-stage is realized in 0.18 {mu}m CMOS technology. The measurement results show that the power consumption of the whole system is very low. The system consumes 730 {mu}A while operating at 1.8 V. The minimum ASK signal the system could detect is 0.7 mV (peak to peak amplitude). (semiconductor integrated circuits)

  11. The parametric open-plus-closed-loop control of chaotic maps and its robustness

    International Nuclear Information System (INIS)

    Chen Liqun

    2004-01-01

    This paper proposes a parametric open-plus-closed-loop control approach to controlling chaos. The logistic map is treated as an example to demonstrate the application of the proposed approach. It is proved that the approach is robust to the model error. Its relations to the open-plus-closed-loop control and the parametric entrainment control are discussed

  12. VME-based remote instrument control without ground loops

    CERN Document Server

    Belleman, J; González, J L

    1997-01-01

    New electronics has been developed for the remote control of the pick-up electrodes at the CERN Proton Synchrotron (PS). Communication between VME-based control computers and remote equipment is via full duplex point-to-point digital data links. Data are sent and received in serial format over simple twisted pairs at a rate of 1 Mbit/s, for distances of up to 300 m. Coupling transformers are used to avoid ground loops. The link hardware consists of a general-purpose VME-module, the 'TRX' (transceiver), containing four FIFO-buffered communication channels, and a dedicated control card for each remote station. Remote transceiver electronics is simple enough not to require micro-controllers or processors. Currently, some sixty pick-up stations of various types, all over the PS Complex (accelerators and associated beam transfer lines) are equipped with the new system. Even though the TRX was designed primarily for communication with pick-up electronics, it could also be used for other purposes, for example to for...

  13. Virtual velocity loop based on MEMS accelerometers for optical stabilization control system

    Science.gov (United States)

    Ren, Wei; Deng, Chao; Mao, Yao; Ren, Ge

    2017-08-01

    In the optical stabilization control system (OSCS) control system based on a charge-coupled device (CCD), stabilization performance of the line-of-sight is severely limited by the mechanical resonance and the low sampling rate of the CCD. An approach to improve the stabilization performance of the OSCS control system with load restriction based on three loops, including an acceleration loop, a virtual velocity loop, and a position loop, by using MEMS accelerometers and a CCD is proposed. The velocity signal is obtained by accelerators instead of gyro sensors. Its advantages are low power, low cost, small size, and wide measuring range. A detailed analysis is provided to show how to design the virtual velocity loop and correct virtual velocity loop drift. Experimental results show that the proposed multiloop feedback control method with virtual velocity loop in which the disturbance suppression performance is better than that of the dual loop control with only an acceleration loop and a position loop at low frequency.

  14. Safety culture as a matter of regulatory control and regulatory effectiveness

    International Nuclear Information System (INIS)

    Camargo, C.T.M.; Furieri, E.B.; Arrieta, L.A.I.; Almeida, C.U.C.

    2002-01-01

    More than 15 years have passed since the term 'safety culture' was introduced by the International Nuclear Safety Advisory Group (INSAG), and although the concept now is widely accepted, practical applications and characteristics have been disseminated mainly for nuclear power plant operating organizations. There is still a lack of international guidance on the use of safety culture as a regulatory matter and on the application of the concept within regulatory organizations. This work explores the meaning of safety culture in two different fields: as an element of safety management systems it shall be a matter of regulatory control; as a complementary tool for quality management it should be used to enhance regulatory effectiveness. Brazilian recent experience on regulating nuclear power reactors provide some examples on how the concept of safety culture may influence regulatory strategies and regulatory management. (author)

  15. Microcomputer-controlled flow meter used on a water loop

    International Nuclear Information System (INIS)

    Haniger, L.

    1982-01-01

    The report describes a microcomputer-controlled instrument intended for operational measurement on an experimental water loop. On the basis of pressure and temperature input signals the instrument calculates the specific weight, and for ten operator-selectable measuring channels it calculates the mass flow G(kp/s), or the voluminal flow Q(m 3 /h). On pressing the appropriate push-buttons the built-in display indicates the values of pressure (p) and temperature (t), as well as the values of specific weight γ calculated therefrom. For ten individually selectable channels the instrument displays either the values of the pressure differences of the measuring throttling elements (√Δpsub(i)), or the values of Gsub(i) or Qsub(i) as obtained by calculation. In addition, on pressing the Σ-push-button it summarizes the values of Gsub(i) and Qsub(i) for the selected channels. The device is controlled by an 8085 microprocessor, the analog unit MP 6812 being used as the A/D convertor. The instrument algorithm indicates some possible errors which may concern faults of input signals or mistakes in calculation. (author)

  16. Core Transcriptional Regulatory Circuit Controlled by the TAL1 Complex in Human T Cell Acute Lymphoblastic Leukemia

    OpenAIRE

    Sanda, Takaomi; Lawton, Lee N.; Barrasa, M. Inmaculada; Fan, Zi Peng; Kohlhammer, Holger; Gutierrez, Alejandro; Ma, Wenxue; Tatarek, Jessica; Ahn, Yebin; Kelliher, Michelle A.; Jamieson, Catriona H.M.; Staudt, Louis M.; Young, Richard A.; Look, A. Thomas

    2012-01-01

    The oncogenic transcription factor TAL1/SCL is aberrantly expressed in over 40% of cases of human T-cell acute lymphoblastic leukemia (T-ALL), emphasizing its importance in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GATA3 and RUNX1. We show that TAL1 forms a positive interconnected auto-regulatory loop with GATA3 and RUNX1, and that the TAL1 complex directly activates the MY...

  17. Application of neural network technology to setpoint control of a simulated reactor experiment loop

    International Nuclear Information System (INIS)

    Cordes, G.A.; Bryan, S.R.; Powell, R.H.; Chick, D.R.

    1991-01-01

    This paper describes the design, implementation, and application of artificial neural networks to achieve temperature and flow rate control for a simulation of a typical experiment loop in the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory (INEL). The goal of the project was to research multivariate, nonlinear control using neural networks. A loop simulation code was adapted for the project and used to create a training set and test the neural network controller for comparison with the existing loop controllers. The results for the best neural network design are documented and compared with existing loop controller action. The neural network was shown to be as accurate at loop control as the classical controllers in the operating region represented by the training set. 5 refs., 8 figs., 3 tabs

  18. Removal of regulatory controls for materials and sites

    International Nuclear Information System (INIS)

    2004-01-01

    Issues with the removal of regulatory controls are very important on the agenda of the regulatory authorities dealing with radioactive waste management (RWM). These issues arise prominently in decommissioning and in site remediation, and decisions can be very wide ranging having potentially important economic impacts and reaching outside the RWM area. The RWMC Regulators Forum started to address these issues by holding a topical discussion at its meeting in March 2003. Ths present document collates the national regulatory positions in the area of removal of regulatory controls. A summary of the national positions is also provided. The document is up to date to April 2004. (authors)

  19. Closed-loop control of renal perfusion pressure in physiological experiments.

    Science.gov (United States)

    Campos-Delgado, D U; Bonilla, I; Rodríguez-Martínez, M; Sánchez-Briones, M E; Ruiz-Hernández, E

    2013-07-01

    This paper presents the design, experimental modeling, and control of a pump-driven renal perfusion pressure (RPP)-regulatory system to implement precise and relatively fast RPP regulation in rats. The mechatronic system is a simple, low-cost, and reliable device to automate the RPP regulation process based on flow-mediated occlusion. Hence, the regulated signal is the RPP measured in the left femoral artery of the rat, and the manipulated variable is the voltage applied to a dc motor that controls the occlusion of the aorta. The control system is implemented in a PC through the LabView software, and a data acquisition board NI USB-6210. A simple first-order linear system is proposed to approximate the dynamics in the experiment. The parameters of the model are chosen to minimize the error between the predicted and experimental output averaged from eight input/output datasets at different RPP operating conditions. A closed-loop servocontrol system based on a pole-placement PD controller plus dead-zone compensation was proposed for this purpose. First, the feedback structure was validated in simulation by considering parameter uncertainty, and constant and time-varying references. Several experimental tests were also conducted to validate in real time the closed-loop performance for stepwise and fast switching references, and the results show the effectiveness of the proposed automatic system to regulate the RPP in the rat, in a precise, accurate (mean error less than 2 mmHg) and relatively fast mode (10-15 s of response time).

  20. Closed-loop analysis and control of a non-inverting buck-boost converter

    Science.gov (United States)

    Chen, Zengshi; Hu, Jiangang; Gao, Wenzhong

    2010-11-01

    In this article, a cascade controller is designed and analysed for a non-inverting buck-boost converter. The fast inner current loop uses sliding mode control. The slow outer voltage loop uses the proportional-integral (PI) control. Stability analysis and selection of PI gains are based on the nonlinear closed-loop error dynamics incorporating both the inner and outer loop controllers. The closed-loop system is proven to have a nonminimum phase structure. The voltage transient due to step changes of input voltage or resistance is predictable. The operating range of the reference voltage is discussed. The controller is validated by a simulation circuit. The simulation results show that the reference output voltage is well-tracked under system uncertainties or disturbances, confirming the validity of the proposed controller.

  1. Regulatory controls for NORM contamination: Emerging issues and strategies

    International Nuclear Information System (INIS)

    Wennerberg, Linda

    1992-01-01

    Naturally occurring and accelerator-produced radioactive material (NORM) faces the increasing likelihood of federal or state regulatory control. Public concern and limited preliminary survey data fuel the debate over the necessity, approach, and jurisdiction of a NORM regulatory strategy. This debate requires the resolution of technical controversies and potentially competing state and federal agency interests. An additional facet of the debate is the impact of regulation upon traditionally non-nuclear industries, such as oil and gas production. Regulatory response has been initiated in several states, such as Louisiana's controls on equipment used in oil and gas production, to control specific industrial activities which generate NORM. A more comprehensive, generic federal strategy to control NORM contamination is also under review by the Environmental Protection Agency. This paper will detail the emerging technical issues, federal and state regulatory strategies under consideration, and evaluate the efficacy of selected regulatory approaches. (author)

  2. Current control loop design and analysis based on resonant regulators for microgrid applications

    DEFF Research Database (Denmark)

    Federico, de Bosio; Pastorelli, Michelle; de Sousa Ribeiro, Luiz Antonio

    2015-01-01

    Voltage and current control loops play an important role in the performance of microgrids employing power electronics voltage source inverters. Correct design of feedback loops is essential for the proper operation of these systems. This paper analyzes the influence of state feedback cross......-coupling in the design of resonant regulators for inner current loops in power converters operating in standalone microgrids. It is also demonstrated that the effect of state feedback cross-coupling degrades the performance of the control loops by increasing the steady-state error. Different resonant regulators...

  3. Epidermal growth factor receptor mediated proliferation depends on increased lipid droplet density regulated via a negative regulatory loop with FOXO3/Sirtuin6

    International Nuclear Information System (INIS)

    Penrose, Harrison; Heller, Sandra; Cable, Chloe; Makboul, Rania; Chadalawada, Gita; Chen, Ying; Crawford, Susan E.; Savkovic, Suzana D.

    2016-01-01

    The proliferation of colon cancer cells is mediated in part by epidermal growth factor receptor (EGFR) signaling and requires sustained levels of cellular energy to meet its high metabolic needs. Intracellular lipid droplets (LDs) are a source of energy used for various cellular functions and they are elevated in density in human cancer, yet their regulation and function are not well understood. Here, in human colon cancer cells, EGF stimulates increases in LD density, which depends on EGFR expression and activation as well as the individual cellular capacity for lipid synthesis. Increases in LDs are blockaded by inhibition of PI3K/mTOR and PGE2 synthesis, supporting their dependency on select upstream pathways. In colon cancer cells, silencing of the FOXO3 transcription factor leads to down regulation of SIRT6, a negative regulator of lipid synthesis, and consequent increases in the LD coat protein PLIN2, revealing that increases in LDs depend on loss of FOXO3/SIRT6. Moreover, EGF stimulates loss of FOXO3/SIRT6, which is blockaded by the inhibition of upstream pathways as well as lipid synthesis, revealing existence of a negative regulatory loop between LDs and FOXO3/SIRT6. Elevated LDs are utilized by EGF treatment and their depletion through the inhibition of lipid synthesis or silencing of PLIN2 significantly attenuates proliferation. This novel mechanism of proliferative EGFR signaling leading to elevated LD density in colon cancer cells could potentially be therapeutically targeted for the treatment of tumor progression. - Highlights: • In colon cancer cells, EGFR activation leads to increases in LD density. • EGFR signaling includes PI3K/mTOR and PGE2 leading to lipid synthesis. • Increases in LDs are controlled by a negative regulatory loop with FOXO3/SIRT6. • EGFR mediated colon cancer cell proliferation depends on increased LD density.

  4. Epidermal growth factor receptor mediated proliferation depends on increased lipid droplet density regulated via a negative regulatory loop with FOXO3/Sirtuin6

    Energy Technology Data Exchange (ETDEWEB)

    Penrose, Harrison; Heller, Sandra; Cable, Chloe [Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, 1430 Tulane Ave SL-79, New Orleans, LA 70112 (United States); Makboul, Rania [Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, 1430 Tulane Ave SL-79, New Orleans, LA 70112 (United States); Pathology Department, Assiut University, Assiut (Egypt); Chadalawada, Gita; Chen, Ying [Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, 1430 Tulane Ave SL-79, New Orleans, LA 70112 (United States); Crawford, Susan E. [Department of Pathology, Saint Louis University School of Medicine, 1402 South Grand Blvd, Saint Louis, MO 63104 (United States); Savkovic, Suzana D., E-mail: ssavkovi@tulane.edu [Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, 1430 Tulane Ave SL-79, New Orleans, LA 70112 (United States)

    2016-01-15

    The proliferation of colon cancer cells is mediated in part by epidermal growth factor receptor (EGFR) signaling and requires sustained levels of cellular energy to meet its high metabolic needs. Intracellular lipid droplets (LDs) are a source of energy used for various cellular functions and they are elevated in density in human cancer, yet their regulation and function are not well understood. Here, in human colon cancer cells, EGF stimulates increases in LD density, which depends on EGFR expression and activation as well as the individual cellular capacity for lipid synthesis. Increases in LDs are blockaded by inhibition of PI3K/mTOR and PGE2 synthesis, supporting their dependency on select upstream pathways. In colon cancer cells, silencing of the FOXO3 transcription factor leads to down regulation of SIRT6, a negative regulator of lipid synthesis, and consequent increases in the LD coat protein PLIN2, revealing that increases in LDs depend on loss of FOXO3/SIRT6. Moreover, EGF stimulates loss of FOXO3/SIRT6, which is blockaded by the inhibition of upstream pathways as well as lipid synthesis, revealing existence of a negative regulatory loop between LDs and FOXO3/SIRT6. Elevated LDs are utilized by EGF treatment and their depletion through the inhibition of lipid synthesis or silencing of PLIN2 significantly attenuates proliferation. This novel mechanism of proliferative EGFR signaling leading to elevated LD density in colon cancer cells could potentially be therapeutically targeted for the treatment of tumor progression. - Highlights: • In colon cancer cells, EGFR activation leads to increases in LD density. • EGFR signaling includes PI3K/mTOR and PGE2 leading to lipid synthesis. • Increases in LDs are controlled by a negative regulatory loop with FOXO3/SIRT6. • EGFR mediated colon cancer cell proliferation depends on increased LD density.

  5. Regulatory accessibility and social influences on state self-control.

    Science.gov (United States)

    vanDellen, Michelle R; Hoyle, Rick H

    2010-02-01

    The current work examined how social factors influence self-control. Current conceptions of state self-control treat it largely as a function of regulatory capacity. The authors propose that state self-control might also be influenced by social factors because of regulatory accessibility. Studies 1 through 4 provide evidence that individuals' state self-control is influenced by the trait and state self-control of salient others such that thinking of others with good trait or state self-control leads to increases in state self-control and thinking of others with bad trait or state self-control leads to decreases in state self-control. Study 5 provides evidence that the salience of significant others influences both regulatory accessibility and state self-control. Combined, these studies suggest that the effects of social influences on state self-control occur through multiple mechanisms.

  6. Regulatory control of physical protection systems

    International Nuclear Information System (INIS)

    Rajdeep; Mayya, Y.S.

    2017-01-01

    The safety of facilities in BARC is under the regulatory oversight of BSC. The security architecture for these facilities incorporates multiple layers of Physical Protection Systems. The demands of safety may sometimes conflict with the needs of security. Realizing the need to identify these interfaces and extend the regulatory coverage to Physical Protection Systems, a Standing Committee named Physical Protection System Review Committee (PPSRC) has been constituted as a 2"n"d tier entity of BSC. PPSRC includes experts from various domains concerned with nuclear security, viz. physical protection systems, cyber security, radiation safety, security operations, technical services and security administration

  7. Regulatory control, nuclear safety regulation and waste management in Spain

    International Nuclear Information System (INIS)

    Martin, A.

    2000-01-01

    This article presents the challenges that faces the spanish regulatory authority. The deregulation of electricity industry imposes severe changes in nuclear power economics and forces nuclear power to compete with other sources of electricity. A pressure is perceived for regulatory effectiveness primarily since the cost of regulation is a component of the cost of the product. This effectiveness gain in regulatory control will be reached through systematic strategic analysis, formulation and implementation. The regulatory aspects of plant life extension and of waste management are examined

  8. CLOSED LOOP CONTROL OF EMBEDDED Z-SOURCE INVERTER WITH FUZZY CONTROLLER FOR SOLAR PV APPLICATIONS

    OpenAIRE

    Midde Mahesh*, K. Leleedhar Rao

    2017-01-01

    This paper proposes the use of Embedded Z –source inverter system with fuzzy controller for Solar Photo Voltaic (PV) applications with adjustable speed drives. Closed loop operation FUZZY control strategies of EZSI system are proposed. EZSI produces the same voltage gain as Z-source inverter (ZSI) but due to the DC sources embedded within the X- shaped impedance network, it has the added advantage of inherent source filtering capability and also reduced capacitor sizing. This can be achiev...

  9. Core transcriptional regulatory circuit controlled by the TAL1 complex in human T cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Sanda, Takaomi; Lawton, Lee N; Barrasa, M Inmaculada; Fan, Zi Peng; Kohlhammer, Holger; Gutierrez, Alejandro; Ma, Wenxue; Tatarek, Jessica; Ahn, Yebin; Kelliher, Michelle A; Jamieson, Catriona H M; Staudt, Louis M; Young, Richard A; Look, A Thomas

    2012-08-14

    The oncogenic transcription factor TAL1/SCL is aberrantly expressed in over 40% of cases of human T cell acute lymphoblastic leukemia (T-ALL), emphasizing its importance in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GATA3, and RUNX1. We show that TAL1 forms a positive interconnected autoregulatory loop with GATA3 and RUNX1 and that the TAL1 complex directly activates the MYB oncogene, forming a positive feed-forward regulatory loop that reinforces and stabilizes the TAL1-regulated oncogenic program. One of the critical downstream targets in this circuitry is the TRIB2 gene, which is oppositely regulated by TAL1 and E2A/HEB and is essential for the survival of T-ALL cells. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Control Loops for the J-PARC RCS Digital Low-Level RF Control

    CERN Document Server

    Schnase, Alexander; Ezura, Eizi; Hara, Keigo; Nomura, Masahiro; Ohmori, Chihiro; Takagi, Akira; Tamura, Fumihiko; Yamamoto, Masanobu; Yoshii, Masahito

    2005-01-01

    The low-level radiofrequency control for the Rapic Cycling Synchrotron of J-PARC is based on digital signal processing. This system controls the acceleration voltages of 12 magnetic alloy loaded cavities. To achive a short overall delay, mandatory for stable loop operation, the data-processing is based on distributed arithmetics in FPGA. Due to the broadband characteristic of the acceleration cavities, no tuning loop is needed. To handle the large beam current, the RF system operates simultaneously with dual harmonics (h=2) and (h=4). The stability of the amplitude loops is limited by the delay of the FIR filters used after downconversion. The phase loop offers several operation modes to define the phase relation of (h=2) and (h=4) between the longitudinal beam signal and the vector-sum of the cavity voltages. Besides the FIR filters, we provide cascaded CIC filters with smoothly varying coefficients. Such a filter tracks the revolution frequency and has a substantially shorter delay, thereby increasing the s...

  11. Asymmetric positive feedback loops reliably control biological responses.

    Science.gov (United States)

    Ratushny, Alexander V; Saleem, Ramsey A; Sitko, Katherine; Ramsey, Stephen A; Aitchison, John D

    2012-04-24

    Positive feedback is a common mechanism enabling biological systems to respond to stimuli in a switch-like manner. Such systems are often characterized by the requisite formation of a heterodimer where only one of the pair is subject to feedback. This ASymmetric Self-UpREgulation (ASSURE) motif is central to many biological systems, including cholesterol homeostasis (LXRα/RXRα), adipocyte differentiation (PPARγ/RXRα), development and differentiation (RAR/RXR), myogenesis (MyoD/E12) and cellular antiviral defense (IRF3/IRF7). To understand why this motif is so prevalent, we examined its properties in an evolutionarily conserved transcriptional regulatory network in yeast (Oaf1p/Pip2p). We demonstrate that the asymmetry in positive feedback confers a competitive advantage and allows the system to robustly increase its responsiveness while precisely tuning the response to a consistent level in the presence of varying stimuli. This study reveals evolutionary advantages for the ASSURE motif, and mechanisms for control, that are relevant to pharmacologic intervention and synthetic biology applications.

  12. The regulatory control of radioactive sources in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Rojkind, Roberto Hector [Autoridade Regulatoria Nuclear, Buenos Aires (Argentina)

    1997-12-31

    Argentina has been conducting nuclear activities for more than forty years, and as early as in 1956 established a Regulatory Authority. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations had been set in Argentina, before the accident in Goiania. The conclusions drawn from that accident encouraged in Argentina the improvement of some regulatory procedures and helped to enhance the quality of the regulatory process. Therefore, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain improved. Some lessons learned in Argentina from the accident in Goiania and the main characteristics of an effective enforcement program helpful to prevent radiological accidents in industrial, medical, research and teaching uses of radioactive sources are presented. (author) 9 refs; e-mail: rrojkind at sede.arn.gov.br

  13. The regulatory control of radioactive sources in Argentina

    International Nuclear Information System (INIS)

    Rojkind, R.H.

    1998-01-01

    Argentina has been conducting nuclear activities for more than forty years, and had established a Regulatory Authority as early as in 1956. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations were in force in Argentina before the accident in Goiania. The conclusions drawn from the Goiania accident encouraged the Argentine authorities to improve some regulatory procedures and helped to enhance the quality of the regulatory process. As a result, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain have improved. Lessons learned in Argentina from the accident in Goiania are presented as well as the main characteristics of an effective enforcement programme to prevent radiological accidents when radioactive sources are used for industrial, medical, research and teaching purposes. (author)

  14. The regulatory control of radioactive sources in Argentina

    International Nuclear Information System (INIS)

    Rojkind, Roberto Hector

    1997-01-01

    Argentina has been conducting nuclear activities for more than forty years, and as early as in 1956 established a Regulatory Authority. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations had been set in Argentina, before the accident in Goiania. The conclusions drawn from that accident encouraged in Argentina the improvement of some regulatory procedures and helped to enhance the quality of the regulatory process. Therefore, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain improved. Some lessons learned in Argentina from the accident in Goiania and the main characteristics of an effective enforcement program helpful to prevent radiological accidents in industrial, medical, research and teaching uses of radioactive sources are presented. (author)

  15. Two-loop electroweak top corrections are they under control?

    CERN Document Server

    Degrassi, G.; Feruglio, F.; Gambino, P.; Vicini, A.; Degrassi, G; Fanchiotti, S; Feruglio, F; Gambino, P; Vicini, A

    1995-01-01

    The assumption that two-loop top corrections are well approximated by the O(G_mu^2 mt^4) contribution is investigated. It is shown that in the case of the ratio neutral-to-charged current amplitudes at zero momentum transfer the O(G_mu^2 mt^2 M_Z^2) terms are numerically comparable to the m_t^4 contribution for realistic values of the top mass. An estimate of the theoretical error due to unknown two-loop top effect is presented for a few observables of LEP interest.

  16. Reliability analysis and component functional allocations for the ESF multi-loop controller design

    International Nuclear Information System (INIS)

    Hur, Seop; Kim, D.H.; Choi, J.K.; Park, J.C.; Seong, S.H.; Lee, D.Y.

    2006-01-01

    This paper deals with the reliability analysis and component functional allocations to ensure the enhanced system reliability and availability. In the Engineered Safety Features, functionally dependent components are controlled by a multi-loop controller. The system reliability of the Engineered Safety Features-Component Control System, especially, the multi-loop controller which is changed comparing to the conventional controllers is an important factor for the Probability Safety Assessment in the nuclear field. To evaluate the multi-loop controller's failure rate of the k-out-of-m redundant system, the binomial process is used. In addition, the component functional allocation is performed to tolerate a single multi-loop controller failure without the loss of vital operation within the constraints of the piping and component configuration, and ensure that mechanically redundant components remain functional. (author)

  17. Exploring the Use of Design of Experiments in Industrial Processes Operating Under Closed-Loop Control

    DEFF Research Database (Denmark)

    Capaci, Francesca; Kulahci, Murat; Vanhatalo, Erik

    2017-01-01

    Industrial manufacturing processes often operate under closed-loop control, where automation aims to keep important process variables at their set-points. In process industries such as pulp, paper, chemical and steel plants, it is often hard to find production processes operating in open loop....... Instead, closed-loop control systems will actively attempt to minimize the impact of process disturbances. However, we argue that an implicit assumption in most experimental investigations is that the studied system is open loop, allowing the experimental factors to freely affect the important system...... responses. This scenario is typically not found in process industries. The purpose of this article is therefore to explore issues of experimental design and analysis in processes operating under closed-loop control and to illustrate how Design of Experiments can help in improving and optimizing...

  18. Speed-Accuracy Trade-Off in Skilled Typewriting: Decomposing the Contributions of Hierarchical Control Loops

    Science.gov (United States)

    Yamaguchi, Motonori; Crump, Matthew J. C.; Logan, Gordon D.

    2013-01-01

    Typing performance involves hierarchically structured control systems: At the higher level, an outer loop generates a word or a series of words to be typed; at the lower level, an inner loop activates the keystrokes comprising the word in parallel and executes them in the correct order. The present experiments examined contributions of the outer-…

  19. Chaos control of third-order phase-locked loops using backstepping nonlinear controller

    International Nuclear Information System (INIS)

    Harb, Ahmad M.; Harb, Bassam A.

    2004-01-01

    Previous study showed that a third-order phase-locked loop (PLL) with sinusoidal phase detector characteristics experienced a Hopf bifurcation point as well as chaotic behavior. As a result, this behavior drives the PLL to the out-of-lock (unstable) state. The analysis was based on a modern nonlinear theory such as bifurcation and chaos. The main goal of this paper is to control this chaotic behavior. A nonlinear controller based on the theory of backstepping is designed. The study showed the effectiveness of the designed nonlinear controller in controlling the undesirable unstable behavior and pulling the PLL back to the in-lock state

  20. LHX2 Mediates the FGF-to-SHH Regulatory Loop during Limb Development

    Directory of Open Access Journals (Sweden)

    Billy A. Watson

    2018-06-01

    Full Text Available During limb development, fibroblast growth factors (Fgfs govern proximal–distal outgrowth and patterning. FGFs also synchronize developmental patterning between the proximal–distal and anterior–posterior axes by maintaining Sonic hedgehog (Shh expression in cells of the zone of polarizing activity (ZPA in the distal posterior mesoderm. Shh, in turn, maintains Fgfs in the apical ectodermal ridge (AER that caps the distal tip of the limb bud. Crosstalk between Fgf and Shh signaling is critical for patterned limb development, but the mechanisms underlying this feedback loop are not well-characterized. Implantation of Fgf beads in the proximal posterior limb bud can maintain SHH expression in the former ZPA domain (evident 3 h after application, while prolonged exposure (24 h can induce SHH outside of this domain. Although temporally and spatially disparate, comparative analysis of transcriptome data from these different populations accentuated genes involved in SHH regulation. Comparative analysis identified 25 candidates common to both treatments, with eight linked to SHH expression or function. Furthermore, we demonstrated that LHX2, a LIM Homeodomain transcription factor, is an intermediate in the FGF-mediated regulation of SHH. Our data suggest that LHX2 acts as a competency factor maintaining distal posterior SHH expression subjacent to the AER.

  1. Regulatory control of maintenance activities in Argentine nuclear power plants

    International Nuclear Information System (INIS)

    Calvo, J.C.; Caruso, G.

    2000-01-01

    The main maintenance objective is to assure that the safety features of structures, components and systems of nuclear power plants are kept as designed. Therefore, there is a direct relationship between safety and maintenance. Owing to the above mentioned, maintenance activities are considered a relevant regulatory issue for the Argentine Nuclear Regulatory Authority (ARN). This paper describes the regulatory control to maintenance activities of Argentine nuclear power plants. It also addresses essential elements for maintenance control, routine inspections, special inspections during planned outages, audits and license conditions and requirements. (author)

  2. Production planning and control of closed-loop supply chains

    NARCIS (Netherlands)

    K. Inderfurth (Karl); R.H. Teunter (Ruud)

    2001-01-01

    textabstractMore and more supply chains emerge that include a return flow of materials. Many original equipment manufacturers are nowadays engaged in the remanufacturing business. In many process industries, production defectives and by-products are reworked. These closed-loop supply chains deserve

  3. Regulatory Accessibility and Social Influences on State Self-Control

    OpenAIRE

    vanDellen, Michelle R.; Hoyle, Rick H.

    2009-01-01

    The current work examined how social factors influence self-control. Current conceptions of state self-control treat it largely as a function of regulatory capacity. The authors propose that state self-control might also be influenced by social factors because of regulatory accessibility. Studies 1 through 4 provide evidence that individuals’ state self-control is influenced by the trait and state self-control of salient others such that thinking of others with good trait or state self-contro...

  4. Regulatory control of radiation sources. Safety guide

    International Nuclear Information System (INIS)

    2004-01-01

    The basic requirements for the protection of persons against exposure to ionizing radiation and for the safety of radiation sources were established in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards), jointly sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Atomic Energy Agency (IAEA), the International Labour Organization (ILO), the OECD Nuclear Energy Agency (OECD/ NEA), the Pan American Health Organization (PAHO) and the World Health Organization (WHO) (the Sponsoring Organizations). The application of the Basic Safety Standards is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities for radiation protection and safety. Requirements relating to the legal and governmental infrastructure for the safety of nuclear facilities and sources of ionizing radiation, radiation protection, the safe management of radioactive waste and the safe transport of radioactive material are established in the Safety Requirements on Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, Safety Standards Series No. GS-R-1. This Safety Guide, which is jointly sponsored by the FAO, the IAEA, the International Labour Office, the PAHO and the WHO, gives detailed guidance on the key elements for the organization and operation of a national regulatory infrastructure for radiation safety, with particular reference to the functions of the national regulatory body that are necessary to ensure the implementation of the Basic Safety Standards. The Safety Guide is based technically on material first published in IAEA-TECDOC-10671, which was jointly sponsored by the FAO, the IAEA, the OECD/NEA, the PAHO and the WHO. The requirements established in GS-R-1 have been taken into account. The Safety Guide is oriented towards national

  5. Double closed-loop cascade control for lower limb exoskeleton with elastic actuation.

    Science.gov (United States)

    Zhu, Yanhe; Zheng, Tianjiao; Jin, Hongzhe; Yang, Jixing; Zhao, Jie

    2015-01-01

    Unlike traditional rigid actuators, the significant features of Series Elastic Actuator (SEA) are stable torque control, lower output impedance, impact resistance and energy storage. Recently, SEA has been applied in many exoskeletons. In such applications, a key issue is how to realize the human-exoskeleton movement coordination. In this paper, double closed-loop cascade control for lower limb exoskeleton with SEA is proposed. This control method consists of inner SEA torque loop and outer contact force loop. Utilizing the SEA torque control with a motor velocity loop, actuation performances of SEA are analyzed. An integrated exoskeleton control system is designed, in which joint angles are calculated by internal encoders and resolvers and contact forces are gathered by external pressure sensors. The double closed-loop cascade control model is established based on the feedback signals of internal and external sensor. Movement experiments are accomplished in our prototype of lower limb exoskeleton. Preliminary results indicate the exoskeleton movements with pilot can be realized stably by utilizing this double closed-loop cascade control method. Feasibility of the SEA in our exoskeleton robot and effectiveness of the control method are verified.

  6. A Method for Precision Closed-Loop Irrigation Using a Modified PID Control Algorithm

    Science.gov (United States)

    Goodchild, Martin; Kühn, Karl; Jenkins, Malcolm; Burek, Kazimierz; Dutton, Andrew

    2016-04-01

    The benefits of closed-loop irrigation control have been demonstrated in grower trials which show the potential for improved crop yields and resource usage. Managing water use by controlling irrigation in response to soil moisture changes to meet crop water demands is a popular approach but requires knowledge of closed-loop control practice. In theory, to obtain precise closed-loop control of a system it is necessary to characterise every component in the control loop to derive the appropriate controller parameters, i.e. proportional, integral & derivative (PID) parameters in a classic PID controller. In practice this is often difficult to achieve. Empirical methods are employed to estimate the PID parameters by observing how the system performs under open-loop conditions. In this paper we present a modified PID controller, with a constrained integral function, that delivers excellent regulation of soil moisture by supplying the appropriate amount of water to meet the needs of the plant during the diurnal cycle. Furthermore, the modified PID controller responds quickly to changes in environmental conditions, including rainfall events which can result in: controller windup, under-watering and plant stress conditions. The experimental work successfully demonstrates the functionality of a constrained integral PID controller that delivers robust and precise irrigation control. Coir substrate strawberry growing trial data is also presented illustrating soil moisture control and the ability to match water deliver to solar radiation.

  7. Distal loop flexibility of a regulatory domain modulates dynamics and activity of C-terminal SRC kinase (csk.

    Directory of Open Access Journals (Sweden)

    Sulyman Barkho

    Full Text Available The Src family of tyrosine kinases (SFKs regulate numerous aspects of cell growth and differentiation and are under the principal control of the C-terminal Src Kinase (Csk. Csk and SFKs share a modular design with the kinase domain downstream of the N-terminal SH2 and SH3 domains that regulate catalytic function and membrane localization. While the function of interfacial segments in these multidomain kinases are well-investigated, little is known about how surface sites and long-range, allosteric coupling control protein dynamics and catalytic function. The SH2 domain of Csk is an essential component for the down-regulation of all SFKs. A unique feature of the SH2 domain of Csk is the tight turn in place of the canonical CD loop in a surface site far removed from kinase domain interactions. In this study, we used a combination of experimental and computational methods to probe the importance of this difference by constructing a Csk variant with a longer SH2 CD loop to mimic the flexibility found in homologous kinase SH2 domains. Our results indicate that while the fold and function of the isolated domain and the full-length kinase are not affected by loop elongation, native protein dynamics that are essential for efficient catalysis are perturbed. We also identify key motifs and routes through which the distal SH2 site might influence catalysis at the active site. This study underscores the sensitivity of intramolecular signaling and catalysis to native protein dynamics that arise from modest changes in allosteric regions while providing a potential strategy to alter intrinsic activity and signaling modulation.

  8. Development of Computational Approaches for Simulation and Advanced Controls for Hybrid Combustion-Gasification Chemical Looping

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Abhinaya; Lou, Xinsheng; Neuschaefer, Carl; Chaudry, Majid; Quinn, Joseph

    2012-07-31

    This document provides the results of the project through September 2009. The Phase I project has recently been extended from September 2009 to March 2011. The project extension will begin work on Chemical Looping (CL) Prototype modeling and advanced control design exploration in preparation for a scale-up phase. The results to date include: successful development of dual loop chemical looping process models and dynamic simulation software tools, development and test of several advanced control concepts and applications for Chemical Looping transport control and investigation of several sensor concepts and establishment of two feasible sensor candidates recommended for further prototype development and controls integration. There are three sections in this summary and conclusions. Section 1 presents the project scope and objectives. Section 2 highlights the detailed accomplishments by project task area. Section 3 provides conclusions to date and recommendations for future work.

  9. Closed-Loop, Non-Venting Thermal Control for Mars EVA Suits, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA seeks new thermal control technology for EVA suits on Mars. The system must be closed-loop and non-venting, have negligible impact on the Martian environment,...

  10. Self-optimizing Uplink Outer Loop Power Control for WCDMA Network

    Directory of Open Access Journals (Sweden)

    A. G. Markoc

    2015-06-01

    Full Text Available The increasing demands for high data rates, drives the efforts for more efficient usage of the finite natural radio spectrum resources. Existing wideband code division multiple access (WCDMA uplink outer loop power control has difficulty to answer to the new load on air interface. The main reason is that the maximum allowed noise rise per single user is fixed value. In worst case uplink load can be so high that all services, including conversational service, could be blocked. In this paper investigation has been performed to present correlation of main system parameters, used by uplink outer loop power control, to uplink load. Simulation has been created and executed to present difference in current implementation of uplink outer loop power control against proposed changes. Proposed solution is self-optimizing uplink outer loop power control in a way that maximum allowed noise rise per single user would be dynamically changed based on current uplink load on cell.

  11. Regulatory controls and slurry fracture injection

    International Nuclear Information System (INIS)

    Dusseault, M. B.; Bilak, R. A.

    1997-01-01

    The technological and regulatory framework necessary for the safe operation of solid waste disposal using slurry fracture injection (SFI) in Saskatchewan and Alberta was studied. Seven current SFI sites were used as the source of experience. Regular audits of volumes, continuous pressure recording, careful deformation monitoring and analysis, and repeated evaluation of reservoir properties were considered to be the essential features. In the case of toxic wastes, microseismic monitoring and regular well interference or tracer tests might be additional measures used to increase confidence in the containment method. Given the recent introduction of SFI technology, guarding against over-regulation was recommended to allow SFI to operate under the most effective operating conditions, and to preserve its attractiveness as an environmentally attractive and safe waste disposal alternative. 5 refs., 3 tabs., 4 figs

  12. Enhanced Performance Controller Design for Stochastic Systems by Adding Extra State Estimation onto the Existing Closed Loop Control

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yuyang; Zhang, Qichun; Wang, Hong

    2016-08-30

    To enhance the performance of the tracking property , this paper presents a novel control algorithm for a class of linear dynamic stochastic systems with unmeasurable states, where the performance enhancement loop is established based on Kalman filter. Without changing the existing closed loop with the PI controller, the compensative controller is designed to minimize the variances of the tracking errors using the estimated states and the propagation of state variances. Moreover, the stability of the closed-loop systems has been analyzed in the mean-square sense. A simulated example is included to show the effectiveness of the presented control algorithm, where encouraging results have been obtained.

  13. Licensing and regulatory control of nuclear power plants in Canada

    International Nuclear Information System (INIS)

    Atchison, R.J.

    1975-01-01

    The paper discusses the safety philosophy adopted in Canada, the safety criteria and regulatory requirements necessary for the application of this philosophy to reactor design and operation, and finally the means by which compliance with Board requirements is effected. It is emphasized that the effectiveness of regulatory control depends not only on the underlying philosophy but also on the detailed way in which it is applied. (orig./HP) [de

  14. Research on the man in the loop control system of the robot arm based on gesture control

    Science.gov (United States)

    Xiao, Lifeng; Peng, Jinbao

    2017-03-01

    The Man in the loop control system of the robot arm based on gesture control research complex real-world environment, which requires the operator to continuously control and adjust the remote manipulator, as the background, completes the specific mission human in the loop entire system as the research object. This paper puts forward a kind of robot arm control system of Man in the loop based on gesture control, by robot arm control system based on gesture control and Virtual reality scene feedback to enhance immersion and integration of operator, to make operator really become a part of the whole control loop. This paper expounds how to construct a man in the loop control system of the robot arm based on gesture control. The system is a complex system of human computer cooperative control, but also people in the loop control problem areas. The new system solves the problems that the traditional method has no immersion feeling and the operation lever is unnatural, the adjustment time is long, and the data glove mode wears uncomfortable and the price is expensive.

  15. IVABRADINE AND QUALITY OF BIOFEEDBACK IN THE LOOP OF PACED BREATHING UNDER THE CONTROL OF HEART RATE VARIABILITY PARAMETERS IN HEALTHY VOLUNTEERS

    Directory of Open Access Journals (Sweden)

    S. A. S. Belal

    2013-06-01

    Full Text Available On 15 healthy volunteers aged from 18 to 22 years the effect of ivabradine on the quality of biofeedback in the loop of paced breathing under the control of heart rate variability parameters were estimated. It was found that ivabradine contributes to an earlier onset and more significant optimization of regulatory systems in systematic sessions of biofeedback that allows to expand the indications for its clinical use.

  16. Closed-Loop Control of Constrained Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2014-03-27

    predicts forces and moments for the class of flapping wing fliers that makes up most insects and hummingbirds. Large bird and butterfly “clap- and...Closed-Loop Control of Constrained Flapping Wing Micro Air Vehicles DISSERTATION Garrison J. Lindholm, Captain, USAF AFIT-ENY-DS-14-M-02 DEPARTMENT...States Air Force, Department of Defense, or the United States Government. AFIT-ENY-DS-14-M-02 Closed-Loop Control of Constrained Flapping Wing Micro Air

  17. A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality

    Science.gov (United States)

    Noël, Emily S.; Verhoeven, Manon; Lagendijk, Anne Karine; Tessadori, Federico; Smith, Kelly; Choorapoikayil, Suma; den Hertog, Jeroen; Bakkers, Jeroen

    2013-11-01

    Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind regulation of organ laterality. Here we identify a Nodal-independent mechanism that drives asymmetric heart looping in zebrafish embryos. In a unique mutant defective for the Nodal-related southpaw gene, preferential dextral looping in the heart is maintained, whereas gut and brain asymmetries are randomized. As genetic and pharmacological inhibition of Nodal signalling does not abolish heart asymmetry, a yet undiscovered mechanism controls heart chirality. This mechanism is tissue intrinsic, as explanted hearts maintain ex vivo retain chiral looping behaviour and require actin polymerization and myosin II activity. We find that Nodal signalling regulates actin gene expression, supporting a model in which Nodal signalling amplifies this tissue-intrinsic mechanism of heart looping.

  18. Considerations of open-loop, closed-loop, and adaptive multicyclic control systems

    Science.gov (United States)

    Chopra, I.; Mccloud, J. L., III

    1981-01-01

    Four different types of self-tuning regulators were studied for multicyclic control of helicopter vibration. A numerical simulation of the helicopter is made, using a multivariable frequency-domain model, in terms of transfer function with six input control harmonics and six output harmonics. The model characteristics vary with flight speed. An off-line identification of model characteristics is made, using the least-squared-error method and using a succession of input and output measurements. The on-line identification of model characteristics is made using the Kalman filter solution. The optimal controls are calculated from the minimization of quadratic performance function based on response and multicyclic inputs. The performance of various regulators or controllers is judged from the stability, transient response, convergence time, and amplitude of the steady state.

  19. Distributed control software of high-performance control-loop algorithm

    CERN Document Server

    Blanc, D

    1999-01-01

    The majority of industrial cooling and ventilation plants require the control of complex processes. All these processes are highly important for the operation of the machines. The stability and reliability of these processes are leading factors identifying the quality of the service provided. The control system architecture and software structure, as well, are required to have high dynamical performance and robust behaviour. The intelligent systems based on PID or RST controllers are used for their high level of stability and accuracy. The design and tuning of these complex controllers require the dynamic model of the plant to be known (generally obtained by identification) and the desired performance of the various control loops to be specified for achieving good performances. The concept of having a distributed control algorithm software provides full automation facilities with well-adapted functionality and good performances, giving methodology, means and tools to master the dynamic process optimization an...

  20. Monitoring control program as a tool for regulatory control

    International Nuclear Information System (INIS)

    Silva Peres, Sueli da; Lauria, Dejanaira C.; Martins, Nadia S.F.; Rio, Monica A.P.

    2008-01-01

    Full text: The Institute of Radiation Protection and Dosimetry (IRD) of the Brazilian Commission of Nuclear Energy (CNEN) is responsible for developing, establishing and carrying out an independent assessment to verify the adequacy, effectiveness and accuracy of environmental radiological control carried out by licensed and controlled facilities. This independent assessment is performed by Environmental Monitoring Control Program (MCP). The MCP is a regulatory control and its main goal is to provide public and environment with an appropriate protection level against harmful effects of ionising radiation. The main purpose of the MCP is to verify whether applicable requirements prescribed by legislation are met, the environmental radiological control of the facilities are adequate and effective and the facilities are able to generate valid measuring results. The MCP is carried out in order to evaluate the quality of environmental radiation monitoring programs (EMP) and the effectiveness of their implementation, sampling conditions in the field, changes of environmental aspects in the impact area, adequacy of and adherence to procedures established and other applicable documents, technical competence of the staff and the necessary resources to ensure the required quality of the EMP. The MCP has been performed by activities should include inspecting and auditing of several types of nuclear and radioactive facilities. The inspection programme include the joint sampling program (CCP). The aim of the CCP is to check data of environmental monitoring of operator. The MCP was implemented in 1994. Ever since several problems related to the environmental control performed by operator was identified. The most important of them include problems related to the preparation and analysis of environmental samples, training of personnel, necessary resources, adherence of procedures to the purpose of the monitoring, fulfillment of procedures established, adequacy of the EMP and EMP

  1. Closed loop control of sedation for colonoscopy using the Bispectral Index

    NARCIS (Netherlands)

    Leslie, K.; Absalom, A.; Kenny, G. N. C.

    Sixteen patients undergoing colonoscopy were sedated with propofol using a closed-loop control system guided by the Bispectral Index (BIS). Propofol administration, via a target-controlled infusion, was controlled by a proportional-integral-differential control algorithm. The median (range) propofol

  2. Performance assessment of static lead-lag feedforward controllers for disturbance rejection in PID control loops.

    Science.gov (United States)

    Yu, Zhenpeng; Wang, Jiandong

    2016-09-01

    This paper assesses the performance of feedforward controllers for disturbance rejection in univariate feedback plus feedforward control loops. The structures of feedback and feedforward controllers are confined to proportional-integral-derivative and static-lead-lag forms, respectively, and the effects of feedback controllers are not considered. The integral squared error (ISE) and total squared variation (TSV) are used as performance metrics. A performance index is formulated by comparing the current ISE and TSV metrics to their own lower bounds as performance benchmarks. A controller performance assessment (CPA) method is proposed to calculate the performance index from measurements. The proposed CPA method resolves two critical limitations in the existing CPA methods, in order to be consistent with industrial scenarios. Numerical and experimental examples illustrate the effectiveness of the obtained results. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Regulatory control of ionizing radiations in Ecuador

    International Nuclear Information System (INIS)

    Benitez, Manuel

    1996-03-01

    This document deals with legal aspects for controlling ionizing radiations, radiological safety regulations and objectives, scopes and features of the national radioprotection planning in Ecuador. (The author)

  4. ROBUST CONTROL OF END-TIDAL CO2 USING THE H∞ LOOP-SHAPING APPROACH

    Directory of Open Access Journals (Sweden)

    Anake Pomprapa

    2013-12-01

    Full Text Available Mechanically ventilated patients require appropriate settings of respiratory control variables to maintain acceptable gas exchange. To control the carbon dioxide (CO2 level effectively and automatically, system identification based on a human subject was performed using a linear affine model and a nonlinear Hammerstein structure. Subsequently, a robust controller was designed using the H∞ loop-shaping approach, which synthesizes the optimal controller based on a specific objective by achieving stability with guaranteed performance. For demonstration purposes, the closed-loop control ventilation system was successfully tested in a human volunteer. The experimental results indicate that the blood CO2 level may indeed be controlled noninvasively by measuring end-tidal CO2 from expired air. Keeping the limited amount of experimental data in mind, we conclude that H∞ loop-shaping may be a promising technique for control of mechanical ventilation in patients with respiratory insufficiency.

  5. Regulatory control of the use of contractors by operating organizations. Peer discussions on regulatory practices

    International Nuclear Information System (INIS)

    2000-09-01

    This report arises from the eighth series of peer discussions on regulatory practices entitled 'Regulatory control of the use of contractors by operating organizations'. Senior regulators from 19 Member States participated in two peer group discussions in March 2000 and May 2000. This report gives an account of the outcomes of these meetings and of practical suggestions put forward by senior regulators. These suggestions do not necessarily reflect the views of the governments of the nominating Member States, the organizations they belong to, or the International Atomic Energy Agency. The objective of this document is to share experience between regulatory bodies and provide practical suggestions for controlling the use of contractors and subcontractors by the operating organizations during all stages, especially operation, of a nuclear power plant, so as to ensure that the quality of work and services delivered is commensurate with the safety importance of the activities and that these are carried out in a manner that will not adversely affect the safe or reliable operation of the facility. These documented practical suggestions and experiences are the result of a series of peer discussions at the IAEA in 2000. It is considered that the manner in which control is exercised, and the various challenges connected to this control, are highly dependent upon the legislative framework, maturity of the nuclear programme, the size of the national nuclear industry and the culture in each country. The report is structured so that it covers the subject matter under the following main headings: Legal Provisions, Regulatory Strategy and Requirements; Regulatory Approaches for Controlling the Use of Contractors; Types of Contracts; Practical Suggestions

  6. Closed loop identification of a piezoelectrically controlled radial gas bearing: Theory and experiment

    DEFF Research Database (Denmark)

    Sekunda, André Krabdrup; Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2018-01-01

    Gas bearing systems have extremely small damping properties. Feedback control is thus employed to increase the damping of gas bearings. Such a feedback loop correlates the input with the measurement noise which in turn makes the assumptions for direct identification invalid. The originality...... of this article lies in the investigation of the impact of using different identification methods to identify a rotor-bearing systems’ dynamic model when a feedback loop is active. Two different identification methods are employed. The first method is open loop Prediction Error Method, while the other method...

  7. Introduction to the study of an optimal control for irradiation loops of the reactor Pegase

    International Nuclear Information System (INIS)

    Guintrand, C.

    1968-07-01

    The control system under consideration is made up of: a regulation unit consisting of a conventional nonlinear looped circuit for static tests, a cycling unit operating in open loop for dynamic tests. After a definition of a mathematical model for an irradiation loop, the behaviour of the regulation unit is studied, first of all theoretically using three-dimensional topological methods, and then by analogue simulation. A prototype unit is under construction and its principal characteristics are given. Finally, as far as the cycling unit is concerned, the first tests involving self-instruction technique, are described. (author) [fr

  8. Investigation of Inner Loop Flight Control Strategies for High-Speed Research

    Science.gov (United States)

    Newman, Brett; Kassem, Ayman

    1999-01-01

    This report describes the activities and findings conducted under contract NAS1-19858 with NASA Langley Research Center. Subject matter is the investigation of suitable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Techniques considered in this body of work are primarily conventional-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include 1) current aeroelastic vehicle modeling procedures require further emphasis and refinement, 2) traditional and nontraditional inner loop flight control strategies employing a single feedback loop do not appear sufficient for highly flexible HSCT class vehicles, 3) inner loop flight control systems will, in all likelihood, require multiple interacting feedback loops, and 4) Ref. H HSCT configuration presents major challenges to designing acceptable closed-loop flight dynamics.

  9. Modifications of Control Loop to Improve the Depth Response of Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Sheng-Ping Hsu

    2014-01-01

    Full Text Available During a constant depth maneuver of an autonomous underwater vehicle (AUV, its pitch attitude and stern plane deflections create forces and moments to achieve equilibrium in the vertical plane. If an AUV has a proportional controller only in its depth control loop, then different weights or centers of gravity will cause different steady-state depth errors at trimmed conditions. In general, a steady-state depth error can be eliminated by adding an integral controller in the depth control loop. However, an improper integrator may lead to a bad transient response, even though the steady-state depth error can finally be eliminated. To remove the steady-state depth error, this study proposes methods that adjust the depth command and add a switching integral controller in the depth control loop. Simulation results demonstrate that the steady-state depth error can be eliminated and the transient response can be improved.

  10. Experimental Study of Flexible Plate Vibration Control by Using Two-Loop Sliding Mode Control Strategy

    Science.gov (United States)

    Yang, Jingyu; Lin, Jiahui; Liu, Yuejun; Yang, Kang; Zhou, Lanwei; Chen, Guoping

    2017-08-01

    It is well known that intelligent control theory has been used in many research fields, novel modeling method (DROMM) is used for flexible rectangular active vibration control, and then the validity of new model is confirmed by comparing finite element model with new model. In this paper, taking advantage of the dynamics of flexible rectangular plate, a two-loop sliding mode (TSM) MIMO approach is introduced for designing multiple-input multiple-output continuous vibration control system, which can overcome uncertainties, disturbances or unstable dynamics. An illustrative example is given in order to show the feasibility of the method. Numerical simulations and experiment confirm the effectiveness of the proposed TSM MIMO controller.

  11. Three-dimensional closed-loop control of self-propelled microjets

    NARCIS (Netherlands)

    Khalil, I.S.M.; Magdanz, Veronika; Schmidt, Oliver S.; Sanchez, Samuel; Misra, Sarthak

    2013-01-01

    We demonstrate precise closed-loop control of microjets under the influence of the magnetic fields in three-dimensional (3D) space. For this purpose, we design a magnetic-based control system that directs the field lines towards reference positions. Microjets align along the controlled field lines

  12. Optimal closed-loop identification test design for internal model control

    NARCIS (Netherlands)

    Zhu, Y.; Bosch, van den P.P.J.

    2000-01-01

    In this work, optimal closed-loop test design for control is studied. Simple design formulas are derived based on the asymptotic theory of Ljung. The control scheme used is internal model control (IMC) and the design constraint is the power of the process output or that of the reference signal. The

  13. Cold plasma: Quality control and regulatory considerations

    Science.gov (United States)

    In recent years, cold plasma has emerged as a promising antimicrobial treatment for fresh and fresh-cut produce, nuts, spices, seeds, and other foods. Research has demonstrated effective control of human pathogens such as Salmonella, Listeria monocytogenes, Escherichia coli O157:H7, norovirus, and o...

  14. The regulatory maze of quality control

    International Nuclear Information System (INIS)

    Stone, T.I.

    1987-01-01

    The appropriateness of specific procedures within a quality control program becomes difficult to assess when an attempt is made to collate all of the available information. This task is discussed from the perspective of the Joint Commission (JCAH Accreditation Manual), HHS(quality assurance program recommendations), equipment manufacturers maintenance schedules, and radiology administrative cost concerns

  15. Real time hardware-in-loop simulation of ESMO satellite attitude control system

    Directory of Open Access Journals (Sweden)

    Rune Finnset

    2006-04-01

    Full Text Available This paper studies attitude control of the ESMO satellite using six reaction thrusters. Bang-bang control with dead-zone and Pulse-Width Modulation (PWM for the modulation of the on-time of the thrusters are treated. Closed loop hardware-in-loop simulations, using themicrocontroller unit (MCU Microchip PIC18F452 for implementation of attitude control and MatLab in a standard PC for simulating satellite dynamics, are carried out. Results for real time simulation are compared with autonomous simulations. The controller gives a satisfactory performance in the real time environment.

  16. A microRNA-mediated regulatory loop modulates NOTCH and MYC oncogenic signals in B- and T-cell malignancies.

    Science.gov (United States)

    Ortega, M; Bhatnagar, H; Lin, A-P; Wang, L; Aster, J C; Sill, H; Aguiar, R C T

    2015-04-01

    Growing evidence suggests that microRNAs (miRNAs) facilitate the cross-talk between transcriptional modules and signal transduction pathways. MYC and NOTCH1 contribute to the pathogenesis of lymphoid malignancies. NOTCH induces MYC, connecting two signaling programs that enhance oncogenicity. Here we show that this relationship is bidirectional and that MYC, via a miRNA intermediary, modulates NOTCH. MicroRNA-30a (miR-30a), a member of a family of miRNAs that are transcriptionally suppressed by MYC, directly binds to and inhibits NOTCH1 and NOTCH2 expression. Using a murine model and genetically modified human cell lines, we confirmed that miR-30a influences NOTCH expression in a MYC-dependent fashion. In turn, through genetic modulation, we demonstrated that intracellular NOTCH1 and NOTCH2, by inducing MYC, suppressed miR-30a. Conversely, pharmacological inhibition of NOTCH decreased MYC expression and ultimately de-repressed miR-30a. Examination of genetic models of gain and loss of miR-30a in diffuse large B-cell lymphoma (DLBCL) and T-acute lymphoblastic leukemia (T-ALL) cells suggested a tumor-suppressive role for this miRNA. Finally, the activity of the miR-30a-NOTCH-MYC loop was validated in primary DLBCL and T-ALL samples. These data define the presence of a miRNA-mediated regulatory circuitry that may modulate the oncogenic signals originating from NOTCH and MYC.

  17. Regulatory perspective on incomplete control rod insertions

    International Nuclear Information System (INIS)

    Chatterton, M.

    1997-01-01

    The incomplete control rod insertions experienced at South Texas Unit 1 and Wolf Creek are of safety concern to the NRC staff because they represent potential precursors to loss of shutdown margin. Even before it was determined if these events were caused by the control rods or by the fuel there was an apparent correlation of the problem with high burnup fuel. It was determined that there was also a correlation between high burnup and high drag forces as well as with rod drop time histories and lack of rod recoil. The NRC staff initial actions were aimed at getting a perspective on the magnitude of the problem as far as the number of plants and the amount of fuel that could be involved, as well as the safety significance in terms of shutdown margin. As tests have been performed and data has been analyzed the focus has shifted more toward understanding the problem and the ways to eliminate it. At this time the staff's understanding of the phenomena is that it was a combination of factors including burnup, power history and temperature. The problem appears to be very sensitive to these factors, the interaction of which is not clearly understood. The model developed by Westinghouse provides a possible explanation but there is not sufficient data to establish confidence levels and sensitivity studies involving the key parameters have not been done. While several fixes to the problem have been discussed, no definitive fixes have been proposed. Without complete understanding of the phenomena, or fixes that clearly eliminate the problem the safety concern remains. The safety significance depends on the amount of shutdown margin lost due to incomplete insertion of the control rods. Were the control rods to stick high in the core, the reactor could not be shutdown by the control rods and other means such as emergency boration would be required

  18. LOOP- SIMULATION OF THE AUTOMATIC FREQUENCY CONTROL SUBSYSTEM OF A DIFFERENTIAL MINIMUM SHIFT KEYING RECEIVER

    Science.gov (United States)

    Davarian, F.

    1994-01-01

    The LOOP computer program was written to simulate the Automatic Frequency Control (AFC) subsystem of a Differential Minimum Shift Keying (DMSK) receiver with a bit rate of 2400 baud. The AFC simulated by LOOP is a first order loop configuration with a first order R-C filter. NASA has been investigating the concept of mobile communications based on low-cost, low-power terminals linked via geostationary satellites. Studies have indicated that low bit rate transmission is suitable for this application, particularly from the frequency and power conservation point of view. A bit rate of 2400 BPS is attractive due to its applicability to the linear predictive coding of speech. Input to LOOP includes the following: 1) the initial frequency error; 2) the double-sided loop noise bandwidth; 3) the filter time constants; 4) the amount of intersymbol interference; and 5) the bit energy to noise spectral density. LOOP output includes: 1) the bit number and the frequency error of that bit; 2) the computed mean of the frequency error; and 3) the standard deviation of the frequency error. LOOP is written in MS SuperSoft FORTRAN 77 for interactive execution and has been implemented on an IBM PC operating under PC DOS with a memory requirement of approximately 40K of 8 bit bytes. This program was developed in 1986.

  19. A review of control strategies in closed-loop neuroprosthetic systems

    Directory of Open Access Journals (Sweden)

    James Wright

    2016-07-01

    Full Text Available It has been widely recognized that closed-loop neuroprosthetic systems achieve more favorable outcomes for users then equivalent open-loop devices. Improved performance of tasks, better usability and greater embodiment have all been reported in systems utilizing some form of feedback. However the interdisciplinary work on neuroprosthetic systems can lead to miscommunication due to similarities in well established nomenclature in different fields. Here we present a review of control strategies in existing experimental, investigational and clinical neuroprosthetic systems in order to establish a baseline and promote a common understanding of different feedback modes and closed-loop controllers. The first section provides a brief discussion of feedback control and control theory. The second section reviews the control strategies of recent Brain Machine Interfaces, neuromodulatory implants, neuroprosthetic systems and assistive neurorobotic devices. The final section examines the different approaches to feedback in current neuroprosthetic and neurorobotic systems.

  20. Regulatory control of radiation sources in the Philippines

    International Nuclear Information System (INIS)

    Daroy, Rosita R.

    1995-01-01

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI's regulatory functions are presented. (author)

  1. Criteria of exemption of regulatory control for radioactive material

    International Nuclear Information System (INIS)

    Marco A. Medrano Lopez

    1991-01-01

    Being based on the information contained in the 10 CFR Part 20, of the section 20.301 until the 20.306 where the mechanisms by means of which can prepare the waste of low level are indicated. While the Nuclear Regulatory Commission (NRC) it amended in the year of 1985 the Act of Politics on Low level Wastes, in particular the section 10 of the amendment of the Act, relative to the concept BRC treats those groups of radioactive waste in that their activity contents are so low that they could be exempt of the regulatory control, either liberating them toward the environment or to exempt people or organizations of the regulatory control

  2. Control loop design and control performance study on direct internal reforming solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Weng, S.; Su, M. [Key Laboratory of Power Machinery and Engineering of the Education Ministry, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2009-10-15

    A solid oxide fuel cell (SOFC) stack is a complicated nonlinear power system. Its system model includes a set of partial differential equations that describe species, mass, momentum and energy conservation, as well as the electrochemical reaction models. The validation and verification of the control system by experiment is very expensive and difficult. Based on the distributed and lumped model of a one-dimensional SOFC, the dynamic performance with different control loops for SOFC is investigated. The simulation result proves that the control system is appropriate and feasible, and can effectively satisfy the requirement of variable load power demand. This simulation model not only can prevent some latent dangers of the fuel cell system but also predict the distributed parameters' characteristics inside the SOFC system. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  3. Effective regulatory control of radioactive sources

    International Nuclear Information System (INIS)

    Meserve, R.A.

    2001-01-01

    This paper provides an overview of the situation in the USA regarding government control over use of radiation sources, the challenges it faces and the potential paths to their resolution. In the light of the large number of radiation sources in use worldwide, the safety record on balance is remarkably good. But there is still considerable room for improvement. The IAEA has an important role to play, and it is playing it effectively

  4. Multi-loop control of UPS inverter with a plug-in odd-harmonic repetitive controller.

    Science.gov (United States)

    Razi, Reza; Karbasforooshan, Mohammad-Sadegh; Monfared, Mohammad

    2017-03-01

    This paper proposes an improved multi-loop control scheme for the single-phase uninterruptible power supply (UPS) inverter by using a plug-in odd-harmonic repetitive controller to regulate the output voltage. In the suggested control method, the output voltage and the filter capacitor current are used as the outer and inner loop feedback signals, respectively and the instantaneous value of the reference voltage feedforwarded to the output of the controller. Instead of conventional linear (proportional-integral/-resonant) and conventional repetitive controllers, a plug-in odd-harmonic repetitive controller is employed in the outer loop to regulate the output voltage, which occupies less memory space and offers faster tracking performance compared to the conventional one. Also, a simple proportional controller is used in the inner loop for active damping of possible resonances and improving the transient performance. The feedforward of the converter reference voltage enhances the robust performance of the system and simplifies the system modelling and the controller design. A step-by-step design procedure is presented for the proposed controller, which guarantees stability of the system under worst-case scenarios. Simulation and experimental results validate the excellent steady-state and transient performance of the proposed control scheme and provide the exact comparison of the proposed method with the conventional multi-loop control method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Regulatory control for safe usage of radiation sources in India

    International Nuclear Information System (INIS)

    Ghosh, P.K.; Sonawane, A.U.

    1998-01-01

    The widespread applications of radioactive materials and radiation generating equipment in the field of industry, medicine agriculture and research in India necessitated the establishment of an efficient regulatory framework and consequently the Atomic Energy Regulatory Board (AERB) was constituted to exercise regulatory control over the safe usage of the radioactive materials and the radiation generating equipment. The Atomic Energy Act, 1962 and the Radiation Protection Rules, 1971 promulgated under the Act forms the basis of radiation safety in India and Chairman, AERB is the Competent Authority to enforce the regulatory provisions of the Radiation Protection Rules, 1971, for safe use of radiation source in the country. AERB has published a number of documents such as Radiation Surveillance Procedures, Standards, Codes, Guides and Manuals for safe use and handling of radioactive materials and radiation generating equipment. Apart from nuclear fuel cycle documents, these publications pertain to industrial radiography, medical application of radiation, transport of radioactive material, industrial gamma irradiators, X-ray units etc. AERB safety related publications are based on international standards e.g. BSS, IAEA, ICRP, ISO etc. This paper outlines the methodology of regulatory control exercised by AERB for safe use of the radioactive materials and the radiation generating equipment in the country. (author)

  6. Simulating closed- and open-loop voluntary movement: a nonlinear control-systems approach.

    Science.gov (United States)

    Davidson, Paul R; Jones, Richard D; Andreae, John H; Sirisena, Harsha R

    2002-11-01

    In many recent human motor control models, including feedback-error learning and adaptive model theory (AMT), feedback control is used to correct errors while an inverse model is simultaneously tuned to provide accurate feedforward control. This popular and appealing hypothesis, based on a combination of psychophysical observations and engineering considerations, predicts that once the tuning of the inverse model is complete the role of feedback control is limited to the correction of disturbances. This hypothesis was tested by looking at the open-loop behavior of the human motor system during adaptation. An experiment was carried out involving 20 normal adult subjects who learned a novel visuomotor relationship on a pursuit tracking task with a steering wheel for input. During learning, the response cursor was periodically blanked, removing all feedback about the external system (i.e., about the relationship between hand motion and response cursor motion). Open-loop behavior was not consistent with a progressive transfer from closed- to open-loop control. Our recently developed computational model of the brain--a novel nonlinear implementation of AMT--was able to reproduce the observed closed- and open-loop results. In contrast, other control-systems models exhibited only minimal feedback control following adaptation, leading to incorrect open-loop behavior. This is because our model continues to use feedback to control slow movements after adaptation is complete. This behavior enhances the internal stability of the inverse model. In summary, our computational model is currently the only motor control model able to accurately simulate the closed- and open-loop characteristics of the experimental response trajectories.

  7. Bidirectional neural interface: Closed-loop feedback control for hybrid neural systems.

    Science.gov (United States)

    Chou, Zane; Lim, Jeffrey; Brown, Sophie; Keller, Melissa; Bugbee, Joseph; Broccard, Frédéric D; Khraiche, Massoud L; Silva, Gabriel A; Cauwenberghs, Gert

    2015-01-01

    Closed-loop neural prostheses enable bidirectional communication between the biological and artificial components of a hybrid system. However, a major challenge in this field is the limited understanding of how these components, the two separate neural networks, interact with each other. In this paper, we propose an in vitro model of a closed-loop system that allows for easy experimental testing and modification of both biological and artificial network parameters. The interface closes the system loop in real time by stimulating each network based on recorded activity of the other network, within preset parameters. As a proof of concept we demonstrate that the bidirectional interface is able to establish and control network properties, such as synchrony, in a hybrid system of two neural networks more significantly more effectively than the same system without the interface or with unidirectional alternatives. This success holds promise for the application of closed-loop systems in neural prostheses, brain-machine interfaces, and drug testing.

  8. Adaptive Sliding Mode Control of Dynamic Systems Using Double Loop Recurrent Neural Network Structure.

    Science.gov (United States)

    Fei, Juntao; Lu, Cheng

    2018-04-01

    In this paper, an adaptive sliding mode control system using a double loop recurrent neural network (DLRNN) structure is proposed for a class of nonlinear dynamic systems. A new three-layer RNN is proposed to approximate unknown dynamics with two different kinds of feedback loops where the firing weights and output signal calculated in the last step are stored and used as the feedback signals in each feedback loop. Since the new structure has combined the advantages of internal feedback NN and external feedback NN, it can acquire the internal state information while the output signal is also captured, thus the new designed DLRNN can achieve better approximation performance compared with the regular NNs without feedback loops or the regular RNNs with a single feedback loop. The new proposed DLRNN structure is employed in an equivalent controller to approximate the unknown nonlinear system dynamics, and the parameters of the DLRNN are updated online by adaptive laws to get favorable approximation performance. To investigate the effectiveness of the proposed controller, the designed adaptive sliding mode controller with the DLRNN is applied to a -axis microelectromechanical system gyroscope to control the vibrating dynamics of the proof mass. Simulation results demonstrate that the proposed methodology can achieve good tracking property, and the comparisons of the approximation performance between radial basis function NN, RNN, and DLRNN show that the DLRNN can accurately estimate the unknown dynamics with a fast speed while the internal states of DLRNN are more stable.

  9. Steam drum level control studies of a natural circulation multi loop reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajesh; Contractor, A.D.; Srivastava, Abhishek; Lele, H.G. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Reactor Safety Div.; Vaze, K.K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Reactor Design and Development Group

    2013-12-15

    The proposed heavy water moderated and light water cooled pressure tube type boiling water reactor works on natural circulation at all power levels. It has parallel inter-connected loops with 452 boiling channels in the main heat transport system configuration. These multiple (four) interconnected loops influence the steam drum level control adversely through the common reactor inlet header. Alternate design studies made earlier for efficient control of SD levels have shown favorable results. This has lead to explore further the present scheme with the compartmentalization of CRIH into four compartments catering to four loops separately. The conventional 3-element level control has been found to be working satisfactorily. The interconnections between ECCS header and inlet header compartments have also increased the safety margin for various LOCA and design basis events. The paper deals with the SD level control aspects for this novel MHT configuration which has been analyzed for various PIEs (Postulated Initiating Events) and found to be satisfactory. (orig.)

  10. Regulatory control analysis and design for sewer systems

    DEFF Research Database (Denmark)

    Mollerup, Ane Loft; Mikkelsen, Peter Steen; Thornberg, Dines

    2015-01-01

    A systematic methodology for regulatory control analysis and design is adapted for sewer system operation and evaluated. The main challenge with adapting the methodology is the handling of the stochastic and transient nature of the rainfall disturbances, inherent to sewer system operation...

  11. A digital closed loop control system for automatic phase locking of superconducting cavities of IUAC Linac

    International Nuclear Information System (INIS)

    Dutt, R.N.; Rai, A.; Pandey, A.; Sahu, B.K.; Patra, P.; Karmakar, J.; Chaudhari, G.K.; Mathur, Y.; Ghosh, S.; Kanjilal, D.

    2013-01-01

    A closed loop digital control system has been designed and tested to automate the tuning process of superconducting resonators of LINAC at Inter-University Accelerator Centre, New Delhi. The mechanism controls the proportional valves of the He gas based pneumatic tuner in response to the phase and frequency errors of the cavity RF field. The main RF phase lock loop (PLL) is automatically closed once the resonant frequency is within locking range of the resonator PLL. The digital control scheme was successfully tested on few resonators of LINAC cryostat 1. A high stability of phase lock was observed. The details of the digital automation system are presented in the paper. (author)

  12. Boost converter with combined control loop for a stand-alone photovoltaic battery charge system

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Knott, Arnold; Thomsen, Ole Cornelius

    2013-01-01

    frequency avoids perturbations in the load being propagated to the photovoltaic panel and thus deviating the operating point. Linearization of the photovoltaic panel and converter state-space modeling is performed. In order to achieve stable operation under all operating conditions, the photovoltaic panel......The converter control scheme plays an important role in the performance of maximum power point tracking (MPPT) algorithms. In this paper, an input voltage control with double loop for a stand-alone photovoltaic system is designed and tested. The inner current control loop with high crossover...

  13. Designing control loops for linear and switching power supplies a tutorial guide

    CERN Document Server

    Basso, Christophe P

    2012-01-01

    Loop control is an essential area of electronics engineering that today's professionals need to master. Rather than delving into extensive theory, this practical book focuses on what you really need to know for compensating or stabilizing a given control system. You can turn instantly to practical sections with numerous design examples and ready-made formulas to help you with your projects in the field. You also find coverage of the underpinnings and principles of control loops so you can gain a more complete understanding of the material. This authoritative volume explains how to conduct anal

  14. Transformations to diagonal bases in closed-loop quantum learning control experiments

    International Nuclear Information System (INIS)

    Cardoza, David; Trallero-Herrero, Carlos; Langhojer, Florian; Rabitz, Herschel; Weinacht, Thomas

    2005-01-01

    This paper discusses transformations between bases used in closed-loop learning control experiments. The goal is to transform to a basis in which the number of control parameters is minimized and in which the parameters act independently. We demonstrate a simple procedure for testing whether a unitary linear transformation (i.e., a rotation amongst the control variables) is sufficient to reduce the search problem to a set of globally independent variables. This concept is demonstrated with closed-loop molecular fragmentation experiments utilizing shaped, ultrafast laser pulses

  15. Combining Charge Couple Devices and Rate Sensors for the Feedforward Control System of a Charge Coupled Device Tracking Loop.

    Science.gov (United States)

    Tang, Tao; Tian, Jing; Zhong, Daijun; Fu, Chengyu

    2016-06-25

    A rate feed forward control-based sensor fusion is proposed to improve the closed-loop performance for a charge couple device (CCD) tracking loop. The target trajectory is recovered by combining line of sight (LOS) errors from the CCD and the angular rate from a fiber-optic gyroscope (FOG). A Kalman filter based on the Singer acceleration model utilizes the reconstructive target trajectory to estimate the target velocity. Different from classical feed forward control, additive feedback loops are inevitably added to the original control loops due to the fact some closed-loop information is used. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability. The bandwidth of the Kalman filter is the major factor affecting the control stability and close-loop performance. Both simulations and experiments are provided to demonstrate the benefits of the proposed algorithm.

  16. The Atomic Energy Control Board's regulatory research and support program

    International Nuclear Information System (INIS)

    1988-04-01

    The purpose of the Regulatory Research and Support Program is to augment and extend the capability of the Atomic Energy Control Board's (AECB) regulatory program beyond the capability of in-house resources. The overall objective of the program is to produce pertinent and independent scientific and other knowledge and expertise that will assist the AECB in making correct, timely and credible decisions on regulating the development, application and use of atomic energy. The objectives are achieved through contracted research, development, studies, consultant and other kinds of projects administered by the Research and Radiation Protection Branch (RRB) of the AECB

  17. Current-Loop Control for the Pitching Axis of Aerial Cameras via an Improved ADRC

    Directory of Open Access Journals (Sweden)

    BingYou Liu

    2017-01-01

    Full Text Available An improved active disturbance rejection controller (ADRC is designed to eliminate the influences of the current-loop for the pitching axis control system of an aerial camera. The improved ADRC is composed of a tracking differentiator (TD, an improved extended state observer (ESO, an improved nonlinear state error feedback (NLSEF, and a disturbance compensation device (DCD. The TD is used to arrange transient process. The improved ESO is utilized to observe the state extended by nonlinear dynamics, model uncertainty, and external disturbances. Overtime variation of the current-loop can be predicted by the improved ESO. The improved NLSEF is adopted to restrain the residual errors of the current-loop. The DCD is used to compensate the overtime variation of the current-loop in real time. The improved ADRC is designed based on a new nonlinear function newfal(·. This function exhibits enhanced continuity and smoothness compared to previously available nonlinear functions. Thus, the new nonlinear function can effectively decrease the high-frequency flutter phenomenon. The improved ADRC exhibits improved control performance, and disturbances of the current-loop can be eliminated by the improved ADRC. Finally, simulation experiments are performed. Results show that the improved ADRC displayed better performance than the proportional integral (PI control strategy and traditional ADRC.

  18. The Inverse Optimal Control Problem for a Three-Loop Missile Autopilot

    Science.gov (United States)

    Hwang, Donghyeok; Tahk, Min-Jea

    2018-04-01

    The performance characteristics of the autopilot must have a fast response to intercept a maneuvering target and reasonable robustness for system stability under the effect of un-modeled dynamics and noise. By the conventional approach, the three-loop autopilot design is handled by time constant, damping factor and open-loop crossover frequency to achieve the desired performance requirements. Note that the general optimal theory can be also used to obtain the same gain as obtained from the conventional approach. The key idea of using optimal control technique for feedback gain design revolves around appropriate selection and interpretation of the performance index for which the control is optimal. This paper derives an explicit expression, which relates the weight parameters appearing in the quadratic performance index to the design parameters such as open-loop crossover frequency, phase margin, damping factor, or time constant, etc. Since all set of selection of design parameters do not guarantee existence of optimal control law, explicit inequalities, which are named the optimality criteria for the three-loop autopilot (OC3L), are derived to find out all set of design parameters for which the control law is optimal. Finally, based on OC3L, an efficient gain selection procedure is developed, where time constant is set to design objective and open-loop crossover frequency and phase margin as design constraints. The effectiveness of the proposed technique is illustrated through numerical simulations.

  19. Competent authority regulatory control of the transport of radioactive material

    International Nuclear Information System (INIS)

    1987-04-01

    The purpose of this guide is to assist competent authorities in regulating the transport of radioactive materials and to assist users of transport regulations in their interactions with competent authorities. The guide should assist specifically those countries which are establishing their regulatory framework and further assist countries with established procedures to harmonize their application and implementation of the IAEA Regulations. This guide specifically covers various aspects of the competent authority implementation of the IAEA Regulations for the Safe Transport of Radioactive Material. In addition, physical protection and safeguards control of the transport of nuclear materials as well as third party liability aspects are briefly discussed. This is because they have to be taken into account in overall transport regulatory activities, especially when establishing the regulatory framework

  20. Closed loop control of a flap exposed to harmonic aerodynamic actuation

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Mikkelsen, Robert Flemming; Sørensen, Jens Nørkær

    2012-01-01

    Wind tunnel testing of a two-dimensional aerofoil with a load reducing flap has been conducted under the influence of a closed-loop controller (PID). Upstream synthetic perturbations for well-defined testing of the controller were generated by instrumenting the wind tunnel with two fast turning...

  1. Nanometer range closed-loop control of a stepper micro-motor for data storage

    NARCIS (Netherlands)

    Patrascu, M.; Stramigioli, Stefano; de Boer, Meint J.; Krijnen, Gijsbertus J.M.

    2007-01-01

    We present a nanometer range, closed-loop control study for MEMS stepper actuators. Although generically applicable to other types of stepper motors, the control design presented here was particularly intended for one dimensional shuffle actuators fabricated by surface micromachining technology. The

  2. Numerical static state feedback laws for closed-loop singular optimal control

    NARCIS (Netherlands)

    Graaf, de S.C.; Stigter, J.D.; Straten, van G.

    2005-01-01

    Singular and non-singular control trajectories of agricultural and (bio) chemical processes may need to be recalculated from time to time for use in closed-loop optimal control, because of unforeseen changes in state values and noise. This is time consuming. As an alternative, in this paper,

  3. Regulatory control of radioactivity and nuclear fuel cycle in Canada

    International Nuclear Information System (INIS)

    Hamel, P.E.; Jennekens, J.H.

    1977-05-01

    Legislation and regulations giving birth to the Atomic Energy Control Board (AECB) are outlined, as well as current licencing procedures. The AECB bases its health and safety criteria on ICRP recommendations. R and D is funded to aid regulatory activity. Licencing activities cover uranium resource management, uranium mining and milling, nuclear generating stations, heavy water plants, and radioactive waste management. Safeguards, physical security, and international controls are also concerns of the AECB. (E.C.B.)

  4. Closed loop control of the sawtooth instability in nuclear fusion

    NARCIS (Netherlands)

    Witvoet, G.; Steinbuch, M.; Westerhof, E.; Doelman, N.J.; Baar, de M.R.

    2010-01-01

    In nuclear fusion the sawtooth instability is an important plasma phenomenon, having both positive and negative effects on the tokamak plasma. Control of its period is essential in future nuclear fusion reactors. This paper presents a control oriented model of the sawtooth instability, with current

  5. Droop Control with an Adjustable Complex Virtual Impedance Loop based on Cloud Model Theory

    DEFF Research Database (Denmark)

    Li, Yan; Shuai, Zhikang; Xu, Qinming

    2016-01-01

    Droop control framework with an adjustable virtual impedance loop is proposed in this paper, which is based on the cloud model theory. The proposed virtual impedance loop includes two terms: a negative virtual resistor and an adjustable virtual inductance. The negative virtual resistor term...... sometimes. The cloud model theory is applied to get online the changing line impedance value, which relies on the relevance of the reactive power responding the changing line impedance. The verification of the proposed control strategy is done according to the simulation in a low voltage microgrid in Matlab....

  6. Active stabilization of a rapidly chirped laser by an optoelectronic digital servo-loop control.

    Science.gov (United States)

    Gorju, G; Jucha, A; Jain, A; Crozatier, V; Lorgeré, I; Le Gouët, J-L; Bretenaker, F; Colice, M

    2007-03-01

    We propose and demonstrate a novel active stabilization scheme for wide and fast frequency chirps. The system measures the laser instantaneous frequency deviation from a perfectly linear chirp, thanks to a digital phase detection process, and provides an error signal that is used to servo-loop control the chirped laser. This way, the frequency errors affecting a laser scan over 10 GHz on the millisecond timescale are drastically reduced below 100 kHz. This active optoelectronic digital servo-loop control opens new and interesting perspectives in fields where rapidly chirped lasers are crucial.

  7. Model-based drug administration : current status of target-controlled infusion and closed-loop control

    NARCIS (Netherlands)

    Kuizenga, Merel H.; Vereecke, Hugo E. M.; Struys, Michel M. R. F.

    Purpose of review Drug administration might be optimized by incorporating pharmacokinetic-dynamic (PK/PD) principles and control engineering theories. This review gives an update of the actual status of target-controlled infusion (TCI) and closed-loop computer-controlled drug administration and the

  8. Regulatory aspects of low doses control in Albania

    International Nuclear Information System (INIS)

    Dollani, K.; Kushe, R.

    1997-01-01

    In the present paper are described the status of regulatory aspects of low doses control as well as the existing procedures for their implementation in Albania. According to new Radiological Protection Act, approved by Parliament in 1995, the establishment of the infrastructures in radiation protection area is in course, accompanied by the installation and functioning of new equipment for low dose control. Based in many years experience it is concluded that personal doses of the workers added by practices in Albania are 1/10 of dose Emits. Some particular cases of overexposured workers were investigated. Last times the elements of the optimisation procedures (QA and QC) are outlined in the frame of improving regulatory aspects of low doses control. (author)

  9. The regulatory control of ionizing radiation sources in Lithuania

    International Nuclear Information System (INIS)

    Mastauskas, A.; Ziliukas, J.; Morkunas, G.

    1998-01-01

    The Radiation Protection Centre of the Ministry of Health is the regulatory authority responsible for radiation protection of the public and of workers using sources of ionizing radiation in Lithuania. One of its responsibilities is the control of radioactive sources, which includes keeping the registry, investigating persons arrested while illegally carrying or in possession of radioactive material, decision making and control of users of radioactive sources. The computer based registry contains a directory of more than 24,000 sources and some 800 users in research, medicine and industry. Most of these sources are found in smoke detectors and X ray equipment. The potentially most dangerous sources for therapy and industry (sealed and unsealed) are also listed in this registry. Problems connected with the regulatory control of radioactive sources in Lithuania are presented and their solution is discussed. (author)

  10. Wind turbine model and loop shaping controller design

    Science.gov (United States)

    Gilev, Bogdan

    2017-12-01

    A model of a wind turbine is evaluated, consisting of: wind speed model, mechanical and electrical model of generator and tower oscillation model. Model of the whole system is linearized around of a nominal point. By using the linear model with uncertainties is synthesized a uncertain model. By using the uncertain model is developed a H∞ controller, which provide mode of stabilizing the rotor frequency and damping the tower oscillations. Finally is simulated work of nonlinear system and H∞ controller.

  11. Smart Braid Feedback for the Closed-Loop Control of Soft Robotic Systems.

    Science.gov (United States)

    Felt, Wyatt; Chin, Khai Yi; Remy, C David

    2017-09-01

    This article experimentally investigates the potential of using flexible, inductance-based contraction sensors in the closed-loop motion control of soft robots. Accurate motion control remains a highly challenging task for soft robotic systems. Precise models of the actuation dynamics and environmental interactions are often unavailable. This renders open-loop control impossible, while closed-loop control suffers from a lack of suitable feedback. Conventional motion sensors, such as linear or rotary encoders, are difficult to adapt to robots that lack discrete mechanical joints. The rigid nature of these sensors runs contrary to the aspirational benefits of soft systems. As truly soft sensor solutions are still in their infancy, motion control of soft robots has so far relied on laboratory-based sensing systems such as motion capture, electromagnetic (EM) tracking, or Fiber Bragg Gratings. In this article, we used embedded flexible sensors known as Smart Braids to sense the contraction of McKibben muscles through changes in inductance. We evaluated closed-loop control on two systems: a revolute joint and a planar, one degree of freedom continuum manipulator. In the revolute joint, our proposed controller compensated for elasticity in the actuator connections. The Smart Braid feedback allowed motion control with a steady-state root-mean-square (RMS) error of [1.5]°. In the continuum manipulator, Smart Braid feedback enabled tracking of the desired tip angle with a steady-state RMS error of [1.25]°. This work demonstrates that Smart Braid sensors can provide accurate position feedback in closed-loop motion control suitable for field applications of soft robotic systems.

  12. A closed-loop photon beam control study for the Advanced Light Source

    International Nuclear Information System (INIS)

    Portmann, G.; Bengtsson, J.

    1993-05-01

    The third generation Advanced Light Source (ALS) will produce extremely bright photon beams using undulators and wigglers. In order to position the photon beams accurate to the micron level, a closed-loop feedback system is being developed. Using photon position monitors and dipole corrector magnets, a closed-loop system can automatically compensate for modeling uncertainties and exogenous disturbances. The following paper will present a dynamics model for the perturbations of the closed orbit of the electron beam in the ALS storage ring including the vacuum chamber magnetic field penetration effects. Using this reference model, two closed-loop feedback algorithms will be compared -- a classical PI controller and a two degree-of-freedom approach. The two degree-of-freedom method provides superior disturbance rejection while maintaining the desired performance goals. Both methods will address the need to gain schedule the controller due to the time varying dynamics introduced by changing field strengths when scanning the insertion devices

  13. Field Test of Boiler Primary Loop Temperature Controller

    Energy Technology Data Exchange (ETDEWEB)

    Glanville, P.; Rowley, P.; Schroeder, D.; Brand, L.

    2014-09-01

    Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and in some cases return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential. PARR installed and monitored the performance of one type of ALM controller, the M2G from Greffen Systems, at multifamily sites in the city of Chicago and its suburb Cary, IL, both with existing OTR control. Results show that energy savings depend on the degree to which boilers are over-sized for their load, represented by cycling rates. Also savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, over-sized boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less over-sized boilers at another site showed muted savings.

  14. Field Test of Boiler Primary Loop Temperature Controller

    Energy Technology Data Exchange (ETDEWEB)

    Glanville, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Rowley, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Schroeder, D. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Brand, L. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States)

    2014-09-01

    Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and, in some cases, return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential.

  15. Active Control of Thermal Convection in a Rectangular Loop by Changing its Spatial Orientation

    Science.gov (United States)

    Bratsun, Dmitry A.; Krasnyakov, Ivan V.; Zyuzgin, Alexey V.

    2018-02-01

    The problem of the automatic control of the fluid flow in a rectangular convective loop heated from below is studied theoretically and experimentally. The control is performed by using a feedback subsystem which changes the convection regimes by introducing small discrete changes in the spatial orientation of the loop with respect to gravity. We focus on effects that arise when the feedback controller operates with an unavoidable time delay, which is cause by the thermal inertia of the medium. The mathematical model of the phenomenon is developed. The dynamic regimes of the convection in the thermosyphon loop under control are studied. It is shown that the proposed control method can successfully stabilize not only a no-motion state of the fluid, but also time-dependent modes of convection including the irregular fluid flow at high values of the Rayleigh number. It is shown that the excessive gain of the proportional feedback can result in oscillations in the loop orientation exciting the unsteady convection modes. The comparison of the experimental data obtained for dielectric oil and dodecane with theory is given, and their good agreement is demonstrated.

  16. Controllable recirculators with charged capacitors in a feedback loop

    International Nuclear Information System (INIS)

    Malevich, I.A.; Postoyanov, Yu.I.; Efremenko, D.A.

    1975-01-01

    Devices for generating stable pulse trains in the 100 nsec-10 μsec range and trains of paired pulses with a controllable generation period are described. The parameters of the long-term generation-frequency stability and the probability density of short fluctuations of the period were investigated

  17. The Application of Hardware in the Loop Testing for Distributed Engine Control

    Science.gov (United States)

    Thomas, George L.; Culley, Dennis E.; Brand, Alex

    2016-01-01

    The essence of a distributed control system is the modular partitioning of control function across a hardware implementation. This type of control architecture requires embedding electronics in a multitude of control element nodes for the execution of those functions, and their integration as a unified system. As the field of distributed aeropropulsion control moves toward reality, questions about building and validating these systems remain. This paper focuses on the development of hardware-in-the-loop (HIL) test techniques for distributed aero engine control, and the application of HIL testing as it pertains to potential advanced engine control applications that may now be possible due to the intelligent capability embedded in the nodes.

  18. Lag Synchronization Between Two Coupled Networks via Open-Plus-Closed-Loop and Adaptive Controls

    International Nuclear Information System (INIS)

    Tong-Chun Hu; Yong-Qing Wu; Shi-Xing Li

    2016-01-01

    In this paper, we study lag synchronization between two coupled networks and apply two types of control schemes, including the open-plus-closed-loop (OPCL) and adaptive controls. We then design the corresponding control algorithms according to the OPCL and adaptive feedback schemes. With the designed controllers, we obtain two theorems on the lag synchronization based on Lyapunov stability theory and Barbalat's lemma. Finally we provide numerical examples to show the effectiveness of the obtained controllers and see that the adaptive control is stronger than the OPCL control when realizing the lag synchronization between two coupled networks with different coupling structures. (paper)

  19. Methodologies for Root Locus and Loop Shaping Control Design with Comparisons

    Science.gov (United States)

    Kopasakis, George

    2017-01-01

    This paper describes some basics for the root locus controls design method as well as for loop shaping, and establishes approaches to expedite the application of these two design methodologies to easily obtain control designs that meet requirements with superior performance. The two design approaches are compared for their ability to meet control design specifications and for ease of application using control design examples. These approaches are also compared with traditional Proportional Integral Derivative (PID) control in order to demonstrate the limitations of PID control. Robustness of these designs is covered as it pertains to these control methodologies and for the example problems.

  20. Closed-loop response properties of a visual interneuron involved in fly optomotor control

    Directory of Open Access Journals (Sweden)

    Naveed eEjaz

    2013-03-01

    Full Text Available Due to methodological limitations neural function is mostly studied under open-loop conditions. Normally, however, nervous systems operate in closed-loop where sensory input is processed to generate behavioural outputs, which again change the sensory input. Here, we investigate the closed-loop responses of an identified visual interneuron, the blowfly H1-cell, that is part of a neural circuit involved in optomotor flight and gaze control. Those behaviours may be triggered by attitude changes during flight in turbulent air. The fly analyses the resulting retinal image shifts and performs compensatory body and head rotations to regain its default attitude. We developed a fly-robot interface to study H1-cell responses in a 1 degree-of-freedom image stabilization task. Image shifts, induced by externally forced rotations, modulate the cell’s spike rate that controls counter rotations of a mobile robot to minimize relative motion between the robot and its visual surroundings. A feedback controller closed the loop between neural activity and the rotation of the robot. Under these conditions we found the following H1-cell response properties: (i the peak spike rate decreases when the mean image velocity is increased, (ii the relationship between spike rate and image velocity depends on the standard deviation of the image velocities suggesting adaptive scaling of the cell’s signalling range, and (iii the cell’s gain decreases linearly with increasing image accelerations.Our results reveal a remarkable qualitative similarity between the response dynamics of the H1-cell under closed-loop conditions with those obtained in previous open-loop experiments. Finally, we show that the adaptive scaling of the H1-cell’s responses, while maximizing information on image velocity, decreases the cell’s sensitivity to image accelerations. Understanding such trade-offs in biological vision systems may advance the design of smart vision sensors for autonomous

  1. Closed Loop Control of Active Damped Small DC-link Capacitor Based Drive

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig

    2010-01-01

    be achieved either by modifying the machine current reference or by modifying the machine voltage. The correlation between these two methods is shown by using simple analysis and it is verified by experimental results in a three phase induction machine drive. The effect of current control loop bandwidth...

  2. Regulatory control of radiation sources in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Daroy, Rosita R

    1996-12-31

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI`s regulatory functions are presented. (author). Paper presented during the IAEA Regional (RCA) Workshop on System of Notification, Registration, Licensing, and Control of Radiation Sources and Installations, Jakarta, Indonesia, 24-28 April 1995. 6 refs., 2 figs., 12 tabs.

  3. Regulatory Framework for Controlling the Research Reactor Decommissioning Project

    International Nuclear Information System (INIS)

    Melani, Ai; Chang, Soon Heung

    2009-01-01

    Decommissioning is one of important stages in construction and operation of research reactors. Currently, there are three research reactors operating in Indonesia. These reactors are operated by the National Nuclear Energy Agency (BATAN). The age of the three research reactors varies from 22 to 45 years since the reactors reached their first criticality. Regulatory control of the three reactors is conducted by the Nuclear Energy Regulatory Agency (BAPETEN). Controlling the reactors is carried out based on the Act No. 10/1997 on Nuclear Energy, Government Regulations and BAPETEN Chairman Decrees concerning the nuclear safety, security and safeguards. Nevertheless, BAPETEN still lack of the regulation, especially for controlling the decommissioning project. Therefore, in the near future BAPETEN has to prepare the regulations for decommissioning, particularly to anticipate the decommissioning of the oldest research reactors, which probably will be done in the next ten years. In this papers author give a list of regulations should be prepared by BAPETEN for the decommissioning stage of research reactor in Indonesia based on the international regulatory practice

  4. An overview of the gene regulatory network controlling trichome development in the model plant, Arabidopsis

    Directory of Open Access Journals (Sweden)

    Sitakanta ePattanaik

    2014-06-01

    Full Text Available Trichomes are specialized epidermal cells located on aerial parts of plants and are associated with a wide array of biological processes. Trichomes protect plants from adverse conditions including UV light and herbivore attack and are also an important source of a number of phytochemicals. The simple unicellular trichomes of Arabidopsis serve as an excellent model to study molecular mechanism of cell differentiation and pattern formation in plants. The emerging picture suggests that the developmental process is controlled by a transcriptional network involving three major groups of transcription factors: the R2R3 MYB, basic helix-loop-helix (bHLH and WD40 repeat (WDR protein. These regulatory proteins form a trimeric activator complex that positively regulates trichome development. The single repeat R3 MYBs act as negative regulators of trichome development. They compete with the R2R3 MYBs to bind the bHLH factor and form a repressor complex. In addition to activator-repressor mechanism, a depletion mechanism may operate in parallel during trichome development. In this mechanism, the bHLH factor traps the WDR protein which results in depletion of WDR protein in neighboring cells. Consequently, the cells with high levels of bHLH and WDR proteins are developed into trichomes. A group of C2H2 zinc finger TFs has also been implicated in trichome development. Phytohormones, including gibberellins and jasmonic acid, play significant roles in this developmental process. Recently, microRNAs have been shown to be involved in trichome development. Furthermore, it has been demonstrated that the activities of the key regulatory proteins involved in trichome development are controlled by the 26S/ubiquitin proteasome system (UPS, highlighting the complexity of the regulatory network controlling this developmental process. To complement several excellent recent relevant reviews, this review focuses on the transcriptional network and hormonal interplay

  5. Hepatitis B virus nuclear export elements: RNA stem-loop α and β, key parts of the HBV post-transcriptional regulatory element.

    Science.gov (United States)

    Lim, Chun Shen; Brown, Chris M

    2016-09-01

    Many viruses contain RNA elements that modulate splicing and/or promote nuclear export of their RNAs. The RNAs of the major human pathogen, hepatitis B virus (HBV) contain a large (~600 bases) composite cis-acting 'post-transcriptional regulatory element' (PRE). This element promotes expression from these naturally intronless transcripts. Indeed, the related woodchuck hepadnavirus PRE (WPRE) is used to enhance expression in gene therapy and other expression vectors. These PRE are likely to act through a combination of mechanisms, including promotion of RNA nuclear export. Functional components of both the HBV PRE and WPRE are 2 conserved RNA cis-acting stem-loop (SL) structures, SLα and SLβ. They are within the coding regions of polymerase (P) gene, and both P and X genes, respectively. Based on previous studies using mutagenesis and/or nuclear magnetic resonance (NMR), here we propose 2 covariance models for SLα and SLβ. The model for the 30-nucleotide SLα contains a G-bulge and a CNGG(U) apical loop of which the first and the fourth loop residues form a CG pair and the fifth loop residue is bulged out, as observed in the NMR structure. The model for the 23-nucleotide SLβ contains a 7-base-pair stem and a 9-nucleotide loop. Comparison of the models with other RNA structural elements, as well as similarity searches of human transcriptome and viral genomes demonstrate that SLα and SLβ are specific to HBV transcripts. However, they are well conserved among the hepadnaviruses of non-human primates, the woodchuck and ground squirrel.

  6. Temperature control feedback loops for the linac upgrade side coupled cavities at Fermilab

    International Nuclear Information System (INIS)

    Crisp, J.

    1990-01-01

    The linac upgrade project at Fermilab will replace the last 4 drift-tube linac tanks with seven side coupled cavity strings. This will increase the beam energy from 200 to 400 MeV at injection into the Booster accelerator. The main objective of the temperature loop is to control the resonant frequency of the cavity strings. A cavity string will constant of 4 sections connected with bridge couplers driven with a 12 MW klystron at 805 MHz. Each section is a side coupled cavity chain consisting of 16 accelerating cells and 15 side coupling cells. For the linac upgrade, 7 full cavity strings will be used. A separate temperature control system is planned for each of the 28 accelerating sections, the two transition sections, and the debuncher section. The cavity strings will be tuned to resonance for full power beam loaded conditions. A separate frequency loop is planned that will sample the phase difference between a monitor placed in the end cell of each section and the rf drive. The frequency loop will control the set point for the temperature loop which will be able to maintain the resonant frequency through periods within beam or rf power. The frequency loop will need the intelligence required to determine under what conditions the phase error information is valid and the temperature set point should be adjusted. This paper will discuss some of the reason for temperature control, the implementation, and some of the problems encountered. An appendix contains some useful constants and descriptions of some of the sensor and control elements used. 13 figs

  7. A unified double-loop multi-scale control strategy for NMP integrating-unstable systems

    International Nuclear Information System (INIS)

    Seer, Qiu Han; Nandong, Jobrun

    2016-01-01

    This paper presents a new control strategy which unifies the direct and indirect multi-scale control schemes via a double-loop control structure. This unified control strategy is proposed for controlling a class of highly nonminimum-phase processes having both integrating and unstable modes. This type of systems is often encountered in fed-batch fermentation processes which are very difficult to stabilize via most of the existing well-established control strategies. A systematic design procedure is provided where its applicability is demonstrated via a numerical example. (paper)

  8. Regulatory Mechanisms Controlling Maturation of Serotonin Neuron Identity and Function.

    Science.gov (United States)

    Spencer, William C; Deneris, Evan S

    2017-01-01

    The brain serotonin (5-hydroxytryptamine; 5-HT) system has been extensively studied for its role in normal physiology and behavior, as well as, neuropsychiatric disorders. The broad influence of 5-HT on brain function, is in part due to the vast connectivity pattern of 5-HT-producing neurons throughout the CNS. 5-HT neurons are born and terminally specified midway through embryogenesis, then enter a protracted period of maturation, where they functionally integrate into CNS circuitry and then are maintained throughout life. The transcriptional regulatory networks controlling progenitor cell generation and terminal specification of 5-HT neurons are relatively well-understood, yet the factors controlling 5-HT neuron maturation are only recently coming to light. In this review, we first provide an update on the regulatory network controlling 5-HT neuron development, then delve deeper into the properties and regulatory strategies governing 5-HT neuron maturation. In particular, we discuss the role of the 5-HT neuron terminal selector transcription factor (TF) Pet-1 as a key regulator of 5-HT neuron maturation. Pet-1 was originally shown to positively regulate genes needed for 5-HT synthesis, reuptake and vesicular transport, hence 5-HT neuron-type transmitter identity. It has now been shown to regulate, both positively and negatively, many other categories of genes in 5-HT neurons including ion channels, GPCRs, transporters, neuropeptides, and other transcription factors. Its function as a terminal selector results in the maturation of 5-HT neuron excitability, firing characteristics, and synaptic modulation by several neurotransmitters. Furthermore, there is a temporal requirement for Pet-1 in the control of postmitotic gene expression trajectories thus indicating a direct role in 5-HT neuron maturation. Proper regulation of the maturation of cellular identity is critical for normal neuronal functioning and perturbations in the gene regulatory networks controlling

  9. Regulatory systems for the control of land remediation processes

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, J.; Vijgen, J.; Summersgill, M.

    2003-07-01

    One of the recurring themes in looking at land remediation over the last decade has been identifying and overcoming barriers to the use of innovative, sustainable technologies, whilst still ensuring that there are no adverse environmental impacts from their use. In parallel with this, the regeneration of brownfield sites has increasingly needed effective and economic solutions that leave the site without the stigma of being associated with contamination and waste disposal. Regulatory controls are often identified as one of the main barriers to both of these objectives. Previously, the focus of attention in the study of regulatory controls relating to land contamination has largely been on regimes that trigger the need for clean-up. These may be pollution control legislation or land-use planning controls. However, the focus of this paper will be on the controls on the selection and implementation of the remediation technologies and processes themselves. It will look in particular at the European-wide controls on waste management, pollution prevention and environmental impact assessment. The UK work is being carried out by a working group involving: landowners; developers; public sector regeneration agencies; house-builders; industry; insurers; technology providers; professional advisers; local government authorities; and national government regulators and policy-makers. This multi-stakeholder approach has facilitated the identification of practical, legal, financial and administrative issues to assist in developing new solutions. (orig.)

  10. Demonstration of a vectorial optical field generator with adaptive close loop control.

    Science.gov (United States)

    Chen, Jian; Kong, Lingjiang; Zhan, Qiwen

    2017-12-01

    We experimentally demonstrate a vectorial optical field generator (VOF-Gen) with an adaptive close loop control. The close loop control capability is illustrated with the calibration of polarization modulation of the system. To calibrate the polarization ratio modulation, we generate 45° linearly polarized beam and make it propagate through a linear analyzer whose transmission axis is orthogonal to the incident beam. For the retardation calibration, circularly polarized beam is employed and a circular polarization analyzer with the opposite chirality is placed in front of the CCD as the detector. In both cases, the close loop control automatically changes the value of the corresponding calibration parameters in the pre-set ranges to generate the phase patterns applied to the spatial light modulators and records the intensity distribution of the output beam by the CCD camera. The optimized calibration parameters are determined corresponding to the minimum total intensity in each case. Several typical kinds of vectorial optical beams are created with and without the obtained calibration parameters, and the full Stokes parameter measurements are carried out to quantitatively analyze the polarization distribution of the generated beams. The comparisons among these results clearly show that the obtained calibration parameters could remarkably improve the accuracy of the polarization modulation of the VOF-Gen, especially for generating elliptically polarized beam with large ellipticity, indicating the significance of the presented close loop in enhancing the performance of the VOF-Gen.

  11. Improved process robustness by using closed loop control in deep drawing applications

    Science.gov (United States)

    Barthau, M.; Liewald, M.; Christian, Held

    2017-09-01

    The production of irregular shaped deep-drawing parts with high quality requirements, which are common in today’s automotive production, permanently challenges production processes. High requirements on lightweight construction of passenger car bodies following European regulations until 2020 have been massively increasing the use of high strength steels substantially for years and are also leading to bigger challenges in sheet metal part production. Of course, the more and more complex shapes of today’s car body shells also intensify the issue due to modern and future design criteria. The metal forming technology tries to meet these challenges by developing a highly sophisticated layout of deep drawing dies that consider part quality requirements, process robustness and controlled material flow during the deep or stretch drawing process phase. A new method for controlling material flow using a closed loop system was developed at the IFU Stuttgart. In contrast to previous approaches, this new method allows a control intervention during the deep-drawing stroke. The blank holder force around the outline of the drawn part is used as control variable. The closed loop is designed as trajectory follow up with feed forward control. The used command variable is the part-wall stress that is measured with a piezo-electric measuring pin. In this paper the used control loop will be described in detail. The experimental tool that was built for testing the new control approach is explained here with its features. A method for gaining the follow up trajectories from simulation will also be presented. Furthermore, experimental results considering the robustness of the deep drawing process and the gain in process performance with developed control loop will be shown. Finally, a new procedure for the industrial application of the new control method of deep drawing will be presented by using a new kind of active element to influence the local blank holder pressure onto part

  12. Strengthening the regulatory control of consumer goods through international harmonization

    International Nuclear Information System (INIS)

    Yus Rusdian Akhmad

    2013-01-01

    The International Atomic Energy Agency (IAEA) is currently working on a recommendation in the form of guidelines for regulating consumer goods. Preparation of this document has a significant dimension of international issues, especially in terms of the application of the principles of justification and application of the concept of exemption. International harmonization among regulators ranging from the regional to the global level is a central issue and considering the complex issues that arise in addition to covering the scientific aspects also involve consideration of the legal aspects or values espoused by any State which may differ from one another. PERKA BAPETEN on consumer goods is still in the preparation stage so that the discussion of the material will be useful for improving the quality of the regulation in time. There is a significant gap of understanding to the related materials by the parties concerned (between local and international parties were among the local party). This paper intends to propose the understanding and views on radiation protection and regulatory control for consumer goods and hopely could contributed significantly to strengthening its regulatory control which is primarily through a reduction in the gap of understanding to the related concept that potentially multi perceptions and encourage stronger cooperation among regulatory bodies. (author)

  13. Component Functional Allocations of the ESF Multi-loop Controller for the KNICS ESF-CCS Design

    International Nuclear Information System (INIS)

    Hur, Seop; Choi, Jong Kyun; Kim, Dong Hoon; Kim, Ho; Kim, Seong Tae

    2006-01-01

    The safety related components in nuclear power plants are traditionally controlled by single-loop controllers. Traditional single-loop controller systems utilize dedicated processors for each component but that components independence is compromised through a sharing of power supplies, auxiliary logic modules and auxiliary I/O cards. In the new design of the ESF-CCS, the multi-loop controllers with data networks are widely used. Since components are assigned to ESF-CCS functional groups in a manner consistent with their process relationship, the effects of the failures are predictable and manageable. Therefore, the key issues for the design of multi-loop controller is to allocate the components to the each multi-loop controller through plant and function analysis and grouping. This paper deals with an ESF component functional allocation which is performed through allocation criteria and a fault analysis

  14. Disturbance rejection performance analyses of closed loop control systems by reference to disturbance ratio.

    Science.gov (United States)

    Alagoz, Baris Baykant; Deniz, Furkan Nur; Keles, Cemal; Tan, Nusret

    2015-03-01

    This study investigates disturbance rejection capacity of closed loop control systems by means of reference to disturbance ratio (RDR). The RDR analysis calculates the ratio of reference signal energy to disturbance signal energy at the system output and provides a quantitative evaluation of disturbance rejection performance of control systems on the bases of communication channel limitations. Essentially, RDR provides a straightforward analytical method for the comparison and improvement of implicit disturbance rejection capacity of closed loop control systems. Theoretical analyses demonstrate us that RDR of the negative feedback closed loop control systems are determined by energy spectral density of controller transfer function. In this manner, authors derived design criteria for specifications of disturbance rejection performances of PID and fractional order PID (FOPID) controller structures. RDR spectra are calculated for investigation of frequency dependence of disturbance rejection capacity and spectral RDR analyses are carried out for PID and FOPID controllers. For the validation of theoretical results, simulation examples are presented. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Self-organized critical noise amplification in human closed loop control

    Directory of Open Access Journals (Sweden)

    Felix Patzelt

    2007-11-01

    Full Text Available When humans perform closed loop control tasks like in upright standing or while balancing a stick, their behavior exhibits non-Gaussian fluctuations with long-tailed distributions. The origin of these fluctuations is not known. Here, we investigate if they are caused by selforganized critical noise amplification which emerges in control systems when an unstable dynamics becomes stabilized by an adaptive controller that has finite memory. Starting from this theory, we formulate a realistic model of adaptive closed loop control by including constraints on memory and delays. To test this model, we performed psychophysical experiments where humans balanced an unstable target on a screen. It turned out that the model reproduces the long tails of the distributions together with other characteristic features of the human control dynamics. Fine-tuning the model to match the experimental dynamics identifies parameters characterizing a subject’s control system which can be independently tested. Our results suggest that the nervous system involved in closed loop motor control nearly optimally estimates system parameters on-line from very short epochs of past observations.

  16. Closed loop statistical performance analysis of N-K knock controllers

    Science.gov (United States)

    Peyton Jones, James C.; Shayestehmanesh, Saeed; Frey, Jesse

    2017-09-01

    The closed loop performance of engine knock controllers cannot be rigorously assessed from single experiments or simulations because knock behaves as a random process and therefore the response belongs to a random distribution also. In this work a new method is proposed for computing the distributions and expected values of the closed loop response, both in steady state and in response to disturbances. The method takes as its input the control law, and the knock propensity characteristic of the engine which is mapped from open loop steady state tests. The method is applicable to the 'n-k' class of knock controllers in which the control action is a function only of the number of cycles n since the last control move, and the number k of knock events that have occurred in this time. A Cumulative Summation (CumSum) based controller falls within this category, and the method is used to investigate the performance of the controller in a deeper and more rigorous way than has previously been possible. The results are validated using onerous Monte Carlo simulations, which confirm both the validity of the method and its high computational efficiency.

  17. Control of radioactive sources in industry through regulatory inspections

    International Nuclear Information System (INIS)

    Leocadio, J.C.; Ramalho, A.T.; Pinho, A.S.; Lourenco, M.M.J.; Nicola, M.S.; D'Avila, R.L.; Melo, I.F.; Cucco, A.C.S.

    2005-01-01

    In Brazil, the applications of ionizing radiation in industry are accomplished about 900 radioactive facilities, which handle approximately 3.000 radiation sources. The control of radioactive sources used in industrial installations authorized by the Brazilian Nuclear Energy Commission (CNEN) is accomplished by Servico de Radioprotecao na Industria Radiativa (SERIR) of the Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ, Brazil. This service carries out regulatory inspections in the practices of industrial radiography, nuclear gauges, industrial irradiators and oil wells logging. The frequency of inspections depends on the type of practice, ranging from a year to 5 years, depending on the risk involved. This paper presents a brief description of the situation of radiation safety in the use of radioactive sources in the industries of the country. The results obtained with regulatory inspections at industrial installations demonstrate that the conditions of safety and radiation protection in these facilities are satisfactory when compared with the technical regulations, both national and international

  18. DS-CDMA system outer loop power control and improvement for multi-service

    Institute of Scientific and Technical Information of China (English)

    Guan Mingxiang; Guo Qing; Li Xing

    2008-01-01

    When a new user accesses the CDMA system, the load will change drastically, and therefore, the advanced outer loop power control (OLPC) technology has to be adopted to enrich the target signal interference ratio (SIR) and improve the system performance. The existing problems about DS-CDMA outer loop power control for multi-service are introduced and the power control theoretical model is analyzed. System simulation is adopted on how to obtain the theoretical performance and parameter optimization of the power control algorithm. The OLPC algorithm is improved and the performance comparisons between the old algorithm and the improved algorithm are given. The results show good performance of the improved OLPC algorithm and prove the validity of the improved method for multi-service.

  19. Automatic PID Control Loops Design for Performance Improvement of Cryogenic Turboexpander

    International Nuclear Information System (INIS)

    Joshi, D.M.; Patel, H.K.; Shah, D.K.

    2015-01-01

    Cryogenics field involves temperature below 123 K which is much less than ambient temperature. In addition, many industrially important physical processes—from fulfilling the needs of National Thermonuclear Fusion programs, superconducting magnets to treatment of cutting tools and preservation of blood cells, require extreme low temperature. The low temperature required for liquefaction of common gases can be obtained by several processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Helium liquefier is used for the liquefaction process of helium gas. In general, the Helium Refrigerator/Liquefier (HRL) needs turboexpander as expansion machine to produce cooling effect which is further used for the production of liquid helium. Turboexpanders, a high speed device that is supported on gas bearings, are the most critical component in many helium refrigeration systems. A very minor fault in the operation and manufacturing or impurities in the helium gas can destroy the turboexpander. However, since the performance of expanders is dependent on a number of operating parameters and the relations between them are quite complex, the instrumentation and control system design for turboexpander needs special attention. The inefficiency of manual control leads to the need of designing automatic control loops for turboexpander. Proper design and implementation of the control loops plays an important role in the successful operation of the cryogenic turboexpander. The PID control loops has to be implemented with accurate interlocks and logic to enhance the performance of the cryogenic turboexpander. For different normal and off-normal operations, speeds will be different and hence a proper control method for critical rotational speed avoidance is must. This paper presents the design of PID control loops needed for the

  20. Experimental evaluation of reactivity constraints for the closed-loop control of reactor power

    International Nuclear Information System (INIS)

    Bernard, J.A.; Lanning, D.D.; Ray, A.

    1984-01-01

    General principles for the closed-loop, digital control of reactor power have been identified, quantitatively enumerated, and experimentally demonstrated on the 5 MWt Research Reactor, MITR-II. The basic concept is to restrict the net reactivity so that it is always possible to make the reactor period infinite at the desired termination point of a transient by reversing the direction of motion of whatever control mechanism is associated with the controller. This capability is formally referred to as ''feasibility of control''. A series of ten experiments have been conducted over a period of eighteen months to demonstrate the efficacy of this property for the automatic control of reactor power. It has been shown that a controller which possesses this property is capable of both raising and lowering power in a safe, efficient manner while using a control rod of varying differential worth, that the reactivity constraints are a sufficient condition for the automatic control of reactor power, and that the use of a controller based on reactivity constraints can prevent overshoots either due to attempts to control a transient with a control rod of insufficient differential worth or due to failure to properly estimate when to commence rod insertion. Details of several of the more significant tests are presented together with a discussion of the rationale for the development of closed-loop control in large commercial power systems. Specific consideration is given to the motivation for designing a controller based on feasibility of control and the associated licensing issues

  1. Closed-Loop Process Control for Electron Beam Freeform Fabrication and Deposition Processes

    Science.gov (United States)

    Taminger, Karen M. (Inventor); Hafley, Robert A. (Inventor); Martin, Richard E. (Inventor); Hofmeister, William H. (Inventor)

    2013-01-01

    A closed-loop control method for an electron beam freeform fabrication (EBF(sup 3)) process includes detecting a feature of interest during the process using a sensor(s), continuously evaluating the feature of interest to determine, in real time, a change occurring therein, and automatically modifying control parameters to control the EBF(sup 3) process. An apparatus provides closed-loop control method of the process, and includes an electron gun for generating an electron beam, a wire feeder for feeding a wire toward a substrate, wherein the wire is melted and progressively deposited in layers onto the substrate, a sensor(s), and a host machine. The sensor(s) measure the feature of interest during the process, and the host machine continuously evaluates the feature of interest to determine, in real time, a change occurring therein. The host machine automatically modifies control parameters to the EBF(sup 3) apparatus to control the EBF(sup 3) process in a closed-loop manner.

  2. Regulatory control of nuclear safety in Finland. Annual report 2008

    International Nuclear Information System (INIS)

    Kainulainen, E.

    2009-06-01

    This report covers the regulatory control of nuclear safety in 2008, including the design, construction and operation of nuclear facilities, as well as nuclear waste management and nuclear materials. The control of nuclear facilities and nuclear waste management, as well as nuclear non-proliferation, concern two STUK departments: Nuclear Reactor Regulation and Nuclear Waste and Material Regulation. It constitutes the report on regulatory control in the field of nuclear energy, which the Radiation and Nuclear Safety Authority (STUK) is required to submit to the Ministry of Employment and the Economy pursuant to section 121 of the Finnish Nuclear Energy Decree. The first parts of the report explain the basics of the nuclear safety regulation included as part of STUK's responsibilities, as well as the objectives of the operations, and briefly introduce the objects of regulation. The chapter concerning the development and implementation of legislation and regulations describes changes in nuclear legislation, as well as the progress of STUK's YVL Guide revision. The chapter also includes a summary of the application of the updated YVL Guides to nuclear facilities. The section concerning the regulation of nuclear facilities contains a complete safety assessment of the nuclear facilities currently in operation or under construction. For the nuclear facilities in operation, the section describes plant operation, events during operation, annual maintenance, development of the plants and their safety, and observations made during monitoring. Data and observations gained during regulatory activities are reviewed with a focus on ensuring the safety functions of nuclear facilities and the integrity of structures and components. The report also includes a description of the oversight of the operations and quality management of organisations, oversight of operational experience feedback activities, and the results of these oversight activities. The radiation safety of nuclear

  3. Simplified Models for Analysis and Design of the Control System Main Loops of CAREM Reactor

    International Nuclear Information System (INIS)

    Etchepareborda, Andres; Flury, Celso

    2000-01-01

    The target of this work is to show a few models developed for control analysis and design of the reactor CAREM's main control loops within a broad range of power (between 40 % and 100%).By one side, it is shown the main features of a analytic model programed in MATLAB.This model is based on fitting steady state points at different power levels of the CAREM's RETRAN model.By the other side, it is shown linear models of black-box type denoting the perturbed behavior of the system for each level power point.These models are identified from temporal responses of CAREM's RETRAN model to perturbed input signals over the different steady power level points.Then the dynamics of these models are verified contrasting the temporal responses of the RETRAN model versus the responses of the MATLAB model and the identified models, in each steady power level point.Also are contrasting the frequency response of the linearization of MATLAB model versus the frequency response of the identified models, in each steady power level point.Either the MATLAB model as the identified models are good enough for the control analysis and design of the three main control loops.The MATLAB model has a few differences against the RETRAN model in the primary pressure output variable, that it must be taken into account in the design of this control loop if this model is used.The aim of these models is to represent in a satisfactory way the dynamics of the plant for a later control analysis and design of the control loops in a frequency range between 0.01 rad/seg and 0.3 rad/seg, and a power range between 40 % and 100 %

  4. Regulatory control of nuclear safety in Finland. Annual report 1997

    International Nuclear Information System (INIS)

    Tossavainen, K.

    1998-08-01

    The report describes regulatory control of the use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in Finland in 1997. Nuclear regulatory control ascertained that the operation of Finnish NPPs was in compliance with the conditions set out in operating licences and current regulations. In addition to NPP normal operation, STUK oversaw projects at the plant units relating to power uprating and safety improvements. STUK prepared statements for the Ministry of Trade and Industry about the applications for renewing the operating licenses of Loviisa and Olkiluoto NPPs. The most important items of supervision in nuclear waste management were studies relating to the final disposal of spent fuel from NPPs and the review of the licence application for a repository for low- and intermediate-level reactor waste from Loviisa NPP. Preparation of general safety regulations for the final disposal of spent nuclear fuel, to be published in the form of a Council of State Decision, was started. By safeguards control, the use of nuclear materials was verified to be in compliance with current regulations and that the whereabouts of every batch of nuclear material were always known. Nuclear material safeguards were stepped up to prevent illicit trafficking of nuclear materials and other radioactive materials. In co-operation with the Ministry for Foreign Affairs and the Institute of Seismology (University of Helsinki), preparations were undertaken to implement the Comprehensive Nuclear Test Ban Treaty (CTBT). For enforcement of the Treaty and as part of the international regulatory approach, STUK is currently developing laboratory analyses relating to airborne radioactivity measurements. The focus of co-operation funded by external sources was as follows: improvement of the safety of Kola and Leningrad NPPs, improvement of nuclear waste management in North-West Russia, development of the organizations of nuclear safety authorities in Eastern Europe and development

  5. Development of a Hardware-In-Loop (HIL Simulator for Spacecraft Attitude Control Using Momentum Wheels

    Directory of Open Access Journals (Sweden)

    Dohee Kim

    2008-12-01

    Full Text Available In this paper, a Hardware-In-the-Loop simulator to simulate attitude control of spacecraft using momentum wheels is developed. The simulator consists of a spherical air bearing system allowing rotation and tilt in all three axes, three momentum wheels for actuation, and an AHRS (Attitude Heading Reference System. The simulator processes various types of data in PC104 and wirelessly communicates with a host PC using TCP/IP protocol. A simple low-cost momentum wheel assembly set and its drive electronics are also developed. Several experiments are performed to test the performance of the momentum wheels. For the control performance test of the simulator, a PID controller is implemented. The results of experimental demonstrations confirm the feasibility and validity of the Hardware-In-the-Loop simulator developed in the current study.

  6. Closed-loop control with a coupling factor using an AO system

    International Nuclear Information System (INIS)

    Seo, Y-S; Baik, S-H; Park, S-K; Hong, S-K; Lim, C; Kim, C-J

    2008-01-01

    To stabilize a closed-loop control for a wavefront correction of a distorted laser beam, the instrumentation of an adaptive optics system and the closed-loop wavefront correction algorithms were investigated. We proposed a new control algorithm using a coupling factor from the zonal and the modal ideas. Compensating for an arbitrary wavefront distortion of a laser beam in the real-time, the wavefront correction speed was 5 Hz using the proposed methods of a zonal control with a coupling factor. Although the correction speed is slower in the new algorithm, the correction accuracy is more stable. The experimental results show that the proposed algorithm is appropriate for the wavefront correction of a low frequency fluctuation

  7. Diagnosis of Fault Modes Masked by Control Loops with an Application to Autonomous Hovercraft Systems

    Directory of Open Access Journals (Sweden)

    Ioannis A. Raptis

    2013-01-01

    Full Text Available This paper introduces a methodology for the design, testing and assessment of incipient failure detection techniques for failing components/systems of an autonomous vehicle masked or hidden by feedback control loops. It is recognized that the optimum operation of critical assets (aircraft, autonomous systems, etc. may be compromised by feedback control loops by masking severe fault modes while compensating for typical disturbances. Detrimental consequences of such occurrences include the inability to detect expeditiously and accurately incipient failures, loss of control and inefficient operation of assets in the form of fuel overconsumption and adverse environmental impact. We pursue a systems engineering process to design, construct and test an autonomous hovercraft instrumented appropriately for improved autonomy. Hidden fault modes are detected with performance guarantees by invoking a Bayesian estimation approach called particle filtering. Simulation and experimental studies are employed to demonstrate the efficacy of the proposed methods.

  8. Novel sensors to enable closed-loop active clearance control in gas turbine engines

    Science.gov (United States)

    Geisheimer, Jonathan; Holst, Tom

    2014-06-01

    Active clearance control within the turbine section of gas turbine engines presents and opportunity within aerospace and industrial applications to improve operating efficiencies and the life of downstream components. Open loop clearance control is currently employed during the development of all new large core aerospace engines; however, the ability to measure the gap between the blades and the case and close down the clearance further presents as opportunity to gain even greater efficiencies. The turbine area is one of the harshest environments for long term placement of a sensor in addition to the extreme accuracy requirements required to enable closed loop clearance control. This paper gives an overview of the challenges of clearance measurements within the turbine as well as discusses the latest developments of a microwave sensor designed for this application.

  9. Closed Loop Control of Penetration Depth during CO2 Laser Lap Welding Processes

    Directory of Open Access Journals (Sweden)

    Antonio Ancona

    2012-08-01

    Full Text Available In this paper we describe a novel spectroscopic closed loop control system capable of stabilizing the penetration depth during laser welding processes by controlling the laser power. Our novel approach is to analyze the optical emission from the laser generated plasma plume above the keyhole, to calculate its electron temperature as a process-monitoring signal. Laser power has been controlled by using a quantitative relationship between the penetration depth and the plasma electron temperature. The sensor is able to correlate in real time the difference between the measured electron temperature and its reference value for the requested penetration depth. Accordingly the closed loop system adjusts the power, thus maintaining the penetration depth.

  10. Recovery of Dynamics and Function in Spiking Neural Networks with Closed-Loop Control.

    Science.gov (United States)

    Vlachos, Ioannis; Deniz, Taşkin; Aertsen, Ad; Kumar, Arvind

    2016-02-01

    There is a growing interest in developing novel brain stimulation methods to control disease-related aberrant neural activity and to address basic neuroscience questions. Conventional methods for manipulating brain activity rely on open-loop approaches that usually lead to excessive stimulation and, crucially, do not restore the original computations performed by the network. Thus, they are often accompanied by undesired side-effects. Here, we introduce delayed feedback control (DFC), a conceptually simple but effective method, to control pathological oscillations in spiking neural networks (SNNs). Using mathematical analysis and numerical simulations we show that DFC can restore a wide range of aberrant network dynamics either by suppressing or enhancing synchronous irregular activity. Importantly, DFC, besides steering the system back to a healthy state, also recovers the computations performed by the underlying network. Finally, using our theory we identify the role of single neuron and synapse properties in determining the stability of the closed-loop system.

  11. Regulatory control of nuclear safety in Finland. Annual report 1998

    Energy Technology Data Exchange (ETDEWEB)

    Tossavainen, K. [ed.

    1999-10-01

    The report describes regulatory control of the safe use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in 1998. STUK is the Finnish nuclear safety authority. The submission of this report to the Ministry of Trade and Industry is stipulated in Section 121 of the Nuclear Energy Decree. It was verified by regulatory control that the operation of Finnish NPPs was in compliance with conditions set out in the operating licences of the plants and with regulations currently in force. In addition to supervising the normal operation of the plants, STUK oversaw projects carried out at the plant units, which related to the uprating of their power and the improvement of their safety. STUK issued to the Ministry of Trade and Industry a statement about applications for the renewal of the operating licences of Loviisa and Olkiluoto NPPs, which had been submitted by Imatran Voima Oy and Teollisuuden Voima Oy. Regulatory activities in the field of nuclear waste management were focused on the storage and final disposal of spent fuel as well as the treatment, storage and final disposal of reactor waste. STUK issued a statement to the Ministry of Trade and Industry about an environmental impact assessment programme pertaining to a spent fuel repository project, which had been submitted by Posiva Oy, as well as on Imatran Voima Oy's application concerning the operation of a repository for medium- and low-level reactor waste from Loviisa NPP. The use of nuclear materials was in compliance with the regulations currently in force and also the whereabouts of every batch of nuclear material were ensured by safeguards control. In international safeguards, important changes took place, which were reflected also in safeguards activities at national level. International co-operation continued based on financing both from STUK's budget and from additional sources. The focus of co-operation funded from outside sources was as follows: improvement of the safety of

  12. Regulatory control of nuclear safety in Finland. Annual report 1998

    International Nuclear Information System (INIS)

    Tossavainen, K.

    1999-10-01

    The report describes regulatory control of the safe use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in 1998. STUK is the Finnish nuclear safety authority. The submission of this report to the Ministry of Trade and Industry is stipulated in Section 121 of the Nuclear Energy Decree. It was verified by regulatory control that the operation of Finnish NPPs was in compliance with conditions set out in the operating licences of the plants and with regulations currently in force. In addition to supervising the normal operation of the plants, STUK oversaw projects carried out at the plant units, which related to the uprating of their power and the improvement of their safety. STUK issued to the Ministry of Trade and Industry a statement about applications for the renewal of the operating licences of Loviisa and Olkiluoto NPPs, which had been submitted by Imatran Voima Oy and Teollisuuden Voima Oy. Regulatory activities in the field of nuclear waste management were focused on the storage and final disposal of spent fuel as well as the treatment, storage and final disposal of reactor waste. STUK issued a statement to the Ministry of Trade and Industry about an environmental impact assessment programme pertaining to a spent fuel repository project, which had been submitted by Posiva Oy, as well as on Imatran Voima Oy's application concerning the operation of a repository for medium- and low-level reactor waste from Loviisa NPP. The use of nuclear materials was in compliance with the regulations currently in force and also the whereabouts of every batch of nuclear material were ensured by safeguards control. In international safeguards, important changes took place, which were reflected also in safeguards activities at national level. International co-operation continued based on financing both from STUK's budget and from additional sources. The focus of co-operation funded from outside sources was as follows: improvement of the safety of Kola and

  13. Dynamic modelling and PID loop control of an oil-injected screw compressor package

    Science.gov (United States)

    Poli, G. W.; Milligan, W. J.; McKenna, P.

    2017-08-01

    A significant amount of time is spent tuning the PID (Proportional, Integral and Derivative) control loops of a screw compressor package due to the unique characteristics of the system. Common mistakes incurred during the tuning of a PID control loop include improper PID algorithm selection and unsuitable tuning parameters of the system resulting in erratic and inefficient operation. This paper details the design and development of software that aims to dynamically model the operation of a single stage oil injected screw compressor package deployed in upstream oil and gas applications. The developed software will be used to assess and accurately tune PID control loops present on the screw compressor package employed in controlling the oil pressures, temperatures and gas pressures, in a bid to improve control of the operation of the screw compressor package. Other applications of the modelling software will include its use as an evaluation tool that can estimate compressor package performance during start up, shutdown and emergency shutdown processes. The paper first details the study into the fundamental operational characteristics of each of the components present on the API 619 screw compressor package and then discusses the creation of a dynamic screw compressor model within the MATLAB/Simulink software suite. The paper concludes by verifying and assessing the accuracy of the created compressor model using data collected from physical screw compressor packages.

  14. In-the-loop simulation of electronic automatic temperature control systems: HVAC modeling

    Energy Technology Data Exchange (ETDEWEB)

    Domschke, R.; Matthes, M. [Visteon Deutschland GmbH, Kerpen (Germany)

    2006-07-01

    The Electronic Automatic Temperature Control (EATC) ensures the occupant comfort and provides safety features like rapid defrost and demist protection. Doing this, the EATC controller provides a direct interface to the end consumer and has a considerable impact on customer satisfaction. The In-the-loop (IL) simulation process is an integral part of Visteons model-based development process. It helps to design and calibrate the EATC controller. It consists of several IL simulation techniques like Model-in-the-loop (MIL), Software-in-the-loop (SIL) and Hardware-in-the-loop (HIL). In this article, we will focus on MIL/SIL Simulations. MIL/SIL allows simulation of the EATC controller in a virtual vehicle environment from the early states of and throughout the development process. This ensures a rapid, high quality and robust development process. The MIL/SIL model contains a thermal vehicle model, a heating, ventilation and air conditioning (HVAC) unit model and a model of the EATC controller itself. The thermal vehicle model simulates transient temperature and humidity conditions in the passenger compartment of a vehicle, settings from the controller, heat fluxes through the vehicle shell and windows, solar load and several further boundary conditions. Whereas the thermal vehicle model of a specific vehicle can be adapted from a default data base, one has to pay special attention to the HVAC unit model. Visteon has developed a special, physically based HVAC unit model to be adapted and implemented into the MIL/SIL simulation. This HVAC model enables a straightforward implementation of different HVAC architectures into the MIL/SIL simulation. Moreover, changes in the HVAC settings (i.e. different blower/scroll assemblies) can be assessed and the influence on passenger comfort can be quantified. Examples of the MIL/SIL simulation demonstrate the benefits of this approach. Results are discussed and a further outlook provided. (orig.)

  15. Human regulatory B cells control the TFH cell response.

    Science.gov (United States)

    Achour, Achouak; Simon, Quentin; Mohr, Audrey; Séité, Jean-François; Youinou, Pierre; Bendaoud, Boutahar; Ghedira, Ibtissem; Pers, Jacques-Olivier; Jamin, Christophe

    2017-07-01

    Follicular helper T (T FH ) cells support terminal B-cell differentiation. Human regulatory B (Breg) cells modulate cellular responses, but their control of T FH cell-dependent humoral immune responses is unknown. We sought to assess the role of Breg cells on T FH cell development and function. Human T cells were polyclonally stimulated in the presence of IL-12 and IL-21 to generate T FH cells. They were cocultured with B cells to induce their terminal differentiation. Breg cells were included in these cultures, and their effects were evaluated by using flow cytometry and ELISA. B-cell lymphoma 6, IL-21, inducible costimulator, CXCR5, and programmed cell death protein 1 (PD-1) expressions increased on stimulated human T cells, characterizing T FH cell maturation. In cocultures they differentiated B cells into CD138 + plasma and IgD - CD27 + memory cells and triggered immunoglobulin secretions. Breg cells obtained by Toll-like receptor 9 and CD40 activation of B cells prevented T FH cell development. Added to T FH cell and B-cell cocultures, they inhibited B-cell differentiation, impeded immunoglobulin secretions, and expanded Foxp3 + CXCR5 + PD-1 + follicular regulatory T cells. Breg cells modulated IL-21 receptor expressions on T FH cells and B cells, and their suppressive activities involved CD40, CD80, CD86, and intercellular adhesion molecule interactions and required production of IL-10 and TGF-β. Human Breg cells control T FH cell maturation, expand follicular regulatory T cells, and inhibit the T FH cell-mediated antibody secretion. These novel observations demonstrate a role for the Breg cell in germinal center reactions and suggest that deficient activities might impair the T FH cell-dependent control of humoral immunity and might lead to the development of aberrant autoimmune responses. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  16. Development of a Closed Loop Simulator for Poloidal Field Control in DIII-D

    International Nuclear Information System (INIS)

    J.A. Leuer; M.L. Walker; D.A. Humphreys; J.R. Ferron; A. Nerem; B.G. Penaflor

    1999-01-01

    The design of a model-based simulator of the DIII-D poloidal field system is presented. The simulator is automatically configured to match a particular DIII-D discharge circuit. The simulator can be run in a data input mode, in which prior acquired DIII-D shot data is input to the simulator, or in a stand-alone predictive mode, in which the model operates in closed loop with the plasma control system. The simulator is used to design and validate a multi-input-multi-output controller which has been implemented on DIII-D to control plasma shape. Preliminary experimental controller results are presented

  17. High-accuracy resolver-to-digital conversion via phase locked loop based on PID controller

    Science.gov (United States)

    Li, Yaoling; Wu, Zhong

    2018-03-01

    The problem of resolver-to-digital conversion (RDC) is transformed into the problem of angle tracking control, and a phase locked loop (PLL) method based on PID controller is proposed in this paper. This controller comprises a typical PI controller plus an incomplete differential which can avoid the amplification of higher-frequency noise components by filtering the phase detection error with a low-pass filter. Compared with conventional ones, the proposed PLL method makes the converter a system of type III and thus the conversion accuracy can be improved. Experimental results demonstrate the effectiveness of the proposed method.

  18. Wind turbine inverter robust loop-shaping control subject to grid interaction effects

    DEFF Research Database (Denmark)

    Gryning, Mikkel Peter Sidoroff; Wu, Qiuwei; Blanke, Mogens

    2015-01-01

    the grid and the number of wind turbines connected. Power converter based turbines inject harmonic currents, which are attenuated by passive filters. A robust high order active filter controller is proposed to complement the passive filtering. The H∞ design of the control loop enables desired tracking......An H∞ robust control of wind turbine inverters employing an LCL filter is proposed in this paper. The controller dynamics are designed for selective harmonic filtering in an offshore transmission network subject to parameter perturbations. Parameter uncertainty in the network originates from...

  19. Control of Metastatic Progression by microRNA Regulatory Networks

    Science.gov (United States)

    Pencheva, Nora; Tavazoie, Sohail F.

    2015-01-01

    Aberrant microRNA (miRNA) expression is a defining feature of human malignancy. Specific miRNAs have been identified as promoters or suppressors of metastatic progression. These miRNAs control metastasis through divergent or convergent regulation of metastatic gene pathways. Some miRNA regulatory networks govern cell-autonomous cancer phenotypes, while others modulate the cell-extrinsic composition of the metastatic microenvironment. The use of small RNAs as probes into the molecular and cellular underpinnings of metastasis holds promise for the identification of candidate genes for potential therapeutic intervention. PMID:23728460

  20. Regulatory control of nuclear facility valves and their actuators

    International Nuclear Information System (INIS)

    1993-01-01

    The methods and procedures by which the Finnish Centre for Radiation and Nuclear Safety (STUK) regulates valves and their actuators in nuclear power plants and in other nuclear facilities are specified in the guide. The scope of regulation depends on the Safety Class of the valve and the actuator in question. The Safety Classification principles for the systems, structures and components of the nuclear power plants are described in the guide YVL 2.1 and the regulatory control of the nuclear facility safety valves is described in the guide YVL 5.4

  1. Use and regulatory control of dental X-ray installations

    International Nuclear Information System (INIS)

    1999-01-01

    In the guide the safety requirements concerning dental X-ray installations and their use, prerequisities for exemption from a safety licence, and regulatory control are presented. The guide applies to conventional dental X-ray installations, by which an image is created on an X-ray film or other image receptor placed inside the mouth, and panorama tomography installations for dentition and the cephalostats associated with these. The guide does not apply to multitechnique tomography installations intended for the special imaging of the skull or jaws

  2. Regulatory control of low level radiation exposure in Tanzania

    International Nuclear Information System (INIS)

    Nyanda, A.M.; Muhogora, W.E.

    1997-01-01

    In Tanzania, the radiation protection law was issued in 1983. Under this law, the National Radiation Commission is responsible for safe uses of ionizing radiation. The regulatory control of the resulting doses from the uses of radiation sources in medicine, industry, research and teaching is presented. The system of control reflects the existing interactions between the National Radiation Commission and users through the established radiation protection infrastructure. From the national dose registry data, it is found that the highest annual individual doses over 10 years ago, came from less than 5% of total monitored workers and were in the range 10 - 15 mSv y -1 . The experienced radiation levels in uncontrolled areas of potential workplaces is less than 1 μSv h -1 . The possibility for associating such low dose levels to the effectiveness of the existing regulatory dose control framework is discussed. Despite of this achievement, the need to improve further the radiation protection and safety programs is found necessary. (author)

  3. Towards an Artificial Phonological Loop: An Assistive Device for Working Memory and Attentional Control

    Directory of Open Access Journals (Sweden)

    D. Bogen

    2006-01-01

    Full Text Available We describe the initial development of an artificial phonological loop (APL, a new technology to assist individuals with impairment of the working memory system. The phonological loop, along with the visuospatial sketchpad, is one of the two slave short-term memory subsystems that comprise working memory, a cognitive function closely associated with the control of attention. In the phonological loop, phonological (speech information lasting for 1–2 second is maintained active by repetitive, subvocal (silent speech rehearsal. Deficits in working memory, specifically in the phonological loop, occur in many disorders, including attention-deficit disorder and Alzheimer’s disease. In these disorders, it appears that the ability for phonological rehearsal is intact, but the regulation or triggering of the rehearsal process is inadequate, thus causing the contents of working memory to be lost. The purpose, then, of the APL is to facilitate the phonological loop by artificially extending the duration of phonological rehearsals. The APL mimics the natural phonological loop by providing audible vocal echoes to take the place of subvocal rehearsals. In this system, the user talks to him/herself in short (1–2 second phrases; the device records these phrases, stores them in electronic memory, and then repeats— i.e., echoes—the phrases multiple times over an extended period. Two versions of this device have been developed: the Echo-APL and the Rearticulation-APL. In the Echo-APL, only echoing is involved. In the Rearticulation-APL, however, the user re-vocalizes (rearticulates the phrase in response to an audible cue. The device repeats the cue until it detects (hears the re-vocalization. Future research and development of the APL will require extensive testing and careful evaluation of possible echo-schedules: the predefined program controlling inter-echo time intervals and echo-amplitude (echo loudness. The APL essentially exteriorizes the silent

  4. The SH2 domain of Abl kinases regulates kinase autophosphorylation by controlling activation loop accessibility

    Science.gov (United States)

    Lamontanara, Allan Joaquim; Georgeon, Sandrine; Tria, Giancarlo; Svergun, Dmitri I.; Hantschel, Oliver

    2014-11-01

    The activity of protein kinases is regulated by multiple molecular mechanisms, and their disruption is a common driver of oncogenesis. A central and almost universal control element of protein kinase activity is the activation loop that utilizes both conformation and phosphorylation status to determine substrate access. In this study, we use recombinant Abl tyrosine kinases and conformation-specific kinase inhibitors to quantitatively analyse structural changes that occur after Abl activation. Allosteric SH2-kinase domain interactions were previously shown to be essential for the leukemogenesis caused by the Bcr-Abl oncoprotein. We find that these allosteric interactions switch the Abl activation loop from a closed to a fully open conformation. This enables the trans-autophosphorylation of the activation loop and requires prior phosphorylation of the SH2-kinase linker. Disruption of the SH2-kinase interaction abolishes activation loop phosphorylation. Our analysis provides a molecular mechanism for the SH2 domain-dependent activation of Abl that may also regulate other tyrosine kinases.

  5. Research on Open-Closed-Loop Iterative Learning Control with Variable Forgetting Factor of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Hongbin Wang

    2016-01-01

    Full Text Available We propose an iterative learning control algorithm (ILC that is developed using a variable forgetting factor to control a mobile robot. The proposed algorithm can be categorized as an open-closed-loop iterative learning control, which produces control instructions by using both previous and current data. However, introducing a variable forgetting factor can weaken the former control output and its variance in the control law while strengthening the robustness of the iterative learning control. If it is applied to the mobile robot, this will reduce position errors in robot trajectory tracking control effectively. In this work, we show that the proposed algorithm guarantees tracking error bound convergence to a small neighborhood of the origin under the condition of state disturbances, output measurement noises, and fluctuation of system dynamics. By using simulation, we demonstrate that the controller is effective in realizing the prefect tracking.

  6. OPEN-LOOP CONTROL OF A BIPOLAR STEPPER MOTORS USING THE SPECIALIZED INTEGRATED CIRCUITS

    Directory of Open Access Journals (Sweden)

    Gheorghe BALUTA

    2004-12-01

    Full Text Available This paper describes the open-loop control of a stepper motors. Bipolar stepper motors can be driven with an L297, an L298N bridge driver and very few external components. With an L298N this configuration drives motors with winding currents up to 2.5A. If very high powers are required an equivalent circuit made with discrete transistors replaces the bridge driver. Together these two chips form a complete microprocessor-to-stepper motor interface. The command signals for the controller L297 are generated through an IBM-PC486 interface. It was developed an open-loop command program written in BorlandC programming language.

  7. Closed-loop step response for tuning PID-fractional-order-filter controllers.

    Science.gov (United States)

    Amoura, Karima; Mansouri, Rachid; Bettayeb, Maâmar; Al-Saggaf, Ubaid M

    2016-09-01

    Analytical methods are usually applied for tuning fractional controllers. The present paper proposes an empirical method for tuning a new type of fractional controller known as PID-Fractional-Order-Filter (FOF-PID). Indeed, the setpoint overshoot method, initially introduced by Shamsuzzoha and Skogestad, has been adapted for tuning FOF-PID controller. Based on simulations for a range of first order with time delay processes, correlations have been derived to obtain PID-FOF controller parameters similar to those obtained by the Internal Model Control (IMC) tuning rule. The setpoint overshoot method requires only one closed-loop step response experiment using a proportional controller (P-controller). To highlight the potential of this method, simulation results have been compared with those obtained with the IMC method as well as other pertinent techniques. Various case studies have also been considered. The comparison has revealed that the proposed tuning method performs as good as the IMC. Moreover, it might offer a number of advantages over the IMC tuning rule. For instance, the parameters of the fractional controller are directly obtained from the setpoint closed-loop response data without the need of any model of the plant to be controlled. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Software-in-the-loop simulation of a quadcopter portion for hybrid aircraft control

    Science.gov (United States)

    Mansoor, Shoaib; Saedan, Mana

    2018-01-01

    In this paper, we present the design of the software-in-the-loop simulation framework for a quadcopter that is incorporated in our hybrid aircraft. The hybrid aircraft comprises a quad-copter and a fixed wing with one forward thrust rotor. We need to develop a split control system that utilizes a typical quadcopter controller to control four motors/propellers and a supervisor controller to control a forward thrust rotor. The supervisor controller shall take feedback signals from the quadcopter and will command the fifth rotor for stabilizing the hybrid aircraft and resolves problems like thrust saturation. The simulation simulates the control algorithm and verifies the quadcopter’s behavior using MATLAB and Simulink together. Achieving these results, we come to know how our hybrid controller will be implemented, what results to expect once the forward thrust rotor is attached to the quadcopter. The software-in-the-loop simulation of a quadcopter is one of the most effective methods for verifying overall control performance and safety of the hybrid aircraft before actual hardware implementation and flight test.

  9. Pumped Fluid Loop Heat Rejection and Recovery Systems for Thermal Control of the Mars Science Laboratory

    Science.gov (United States)

    Bhandari, Pradeep; Birur, Gajanana; Prina, Mauro; Ramirez, Brenda; Paris, Anthony; Novak, Keith; Pauken, Michael

    2006-01-01

    This viewgraph presentation reviews the heat rejection and heat recovery system for thermal control of the Mars Science Laboratory (MSL). The MSL mission will use mechanically pumped fluid loop based architecture for thermal control of the spacecraft and rover. The architecture is designed to harness waste heat from an Multi Mission Radioisotope Thermo-electric Generator (MMRTG) during Mars surface operations for thermal control during cold conditions and also reject heat during the cruise aspect of the mission. There are several test that are being conducted that will insure the safety of this concept. This architecture can be used during any future interplanetary missions utilizing radioisotope power systems for power generation.

  10. Vision of the Arc for Quality Documentation and for Closed Loop Control of the Welding Process

    DEFF Research Database (Denmark)

    Kristiansen, Morten; Kristiansen, Ewa; Jensen, Casper Houmann

    2014-01-01

    For gas metal arc welding a vision system was developed, which was robust to monitor the position of the arc. The monitoring documents the welding quality indirectly and a closed loop fuzzy control was implemented to control an even excess penetration. For welding experiments on a butt......-joint with a V-groove with varying root gapthe system demonstrated increased welding quality compared to the system with no control. The system was implemented with a low cost vision system, which makes the system interesting to apply in industrial welding automation systems....

  11. Continuous Drug Infusion for Diabetes Therapy: A Closed-Loop Control System Design

    Directory of Open Access Journals (Sweden)

    Jiming Chen

    2008-03-01

    Full Text Available While a typical way for diabetes therapy is discrete insulin infusion based on long-time interval measurement, in this paper, we design a closed-loop control system for continuous drug infusion to improve the traditional discrete methods and make diabetes therapy automatic in practice. By exploring the accumulative function of drug to insulin, a continuous injection model is proposed. Based on this model, proportional-integral-derivative (PID and fuzzy logic controllers are designed to tackle a control problem of the resulting highly nonlinear plant. Even with serious disturbance of glucose, such as nutrition absorption at meal time, the proposed scheme can perform well in simulation experiments.

  12. Hardware-in-the-loop (HIL) Test of Demand as Frequency Controlled Reserve (DFR)

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Zimmermann, K.; Østergaard, Jacob

    2016-01-01

    This paper presents the hardware-in-the-loop (HIL) test of the demand as frequency controlled reserve (DFR). The HIL test refers to a test in which parts of a pure simulation have been replaced by actual physical components. It is used to understand the behavior of a new device or controller....... The DFR has been tested by offline simulations to illustrate the efficacy of this technology. The DFR control logics have been implemented in the SmartBox. The HIL was conducted by having the SmartBox connected to the real time simulations and the performance of the SmartBox was tested with difference...

  13. Controlling Unknown Saddle Type Steady States of Dynamical Systems with Latency in the Feedback Loop

    DEFF Research Database (Denmark)

    Tamasevicius, Arunas; Bumeliene, Skaidra; Tamaseviciute, Elena

    2009-01-01

    We suggest an adaptive control technique for stabilizing saddle type unstable steady states of dynamical systems. The controller is composed of an unstable and a stable high-pass filters operating in parallel. The mathematical model is considered analytically and numerically. The conjoint...... controller is sufficiently robust to time latencies in the feedback loop. In addition, it is not sensitive to the damping parameters of the system and is relatively fast. Experiments have been performed using a simplified version of the electronic Young-Silva circuit imitating behavior of the Duffing...

  14. Regulatory Strategy to Control Radon Exposure in Pakistan

    International Nuclear Information System (INIS)

    Younus, Irfan; Cho, Kun Woo

    2012-01-01

    Pakistan Nuclear Regulatory Authority (PNRA) was established in 2001 with one of the objectives to ensure the protection of workers, general public and the environment from the harmful effects of naturally occurring and artificially produced ionizing radiations by formulating and implementing the effective regulations. Radon is a naturally occurring odorless, colorless, tasteless, imperceptible to senses and chemically inert radioactive gas which is produced continuously from the natural decay of U-238, U-235 and Th-232 in most soils, rocks and water all over the earth. High levels of radon in the soil and rock are primarily responsible for indoor radon problems. Therefore when inhaled with air, there much probability that radon decay products will stay and decay in the lungs. If stayed in the lungs, the radiation may damage the cells causing lung cancer. Hence the radon problems have been taken seriously in most of the developed countries of the world. Radon reference levels for dwellings and workplaces have been set and the general public has been made alert of radon through newspapers and electronic media. In Pakistan, neither publicity campaign nor radon measurement and control programmes have been started countrywide. Rather small individual efforts for the sake of interest have been done to investigate the radon in some specific area or institution. This paper presents the regulatory strategy to control radon exposure for the sake of radiation protection of public and workers in Pakistan

  15. Embedded Sensors and Controls to Improve Component Performance and Reliability -- Loop-scale Testbed Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Melin, Alexander M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-01

    Embedded instrumentation and control systems that can operate in extreme environments are challenging to design and operate. Extreme environments limit the options for sensors and actuators and degrade their performance. Because sensors and actuators are necessary for feedback control, these limitations mean that designing embedded instrumentation and control systems for the challenging environments of nuclear reactors requires advanced technical solutions that are not available commercially. This report details the development of testbed that will be used for cross-cutting embedded instrumentation and control research for nuclear power applications. This research is funded by the Department of Energy's Nuclear Energy Enabling Technology program's Advanced Sensors and Instrumentation topic. The design goal of the loop-scale testbed is to build a low temperature pump that utilizes magnetic bearing that will be incorporated into a water loop to test control system performance and self-sensing techniques. Specifically, this testbed will be used to analyze control system performance in response to nonlinear and cross-coupling fluid effects between the shaft axes of motion, rotordynamics and gyroscopic effects, and impeller disturbances. This testbed will also be used to characterize the performance losses when using self-sensing position measurement techniques. Active magnetic bearings are a technology that can reduce failures and maintenance costs in nuclear power plants. They are particularly relevant to liquid salt reactors that operate at high temperatures (700 C). Pumps used in the extreme environment of liquid salt reactors provide many engineering challenges that can be overcome with magnetic bearings and their associated embedded instrumentation and control. This report will give details of the mechanical design and electromagnetic design of the loop-scale embedded instrumentation and control testbed.

  16. Hardware-in-the-Loop Simulation for the Automatic Power Control System of Research Reactors

    International Nuclear Information System (INIS)

    Fikry, R.M.; Shehata, S.A.; Elaraby, S.M.; Mahmoud, M.I.; Elbardini, M.M.

    2009-01-01

    Designing and testing digital control system for any nuclear research reactor can be costly and time consuming. In this paper, a rapid, low-cost proto typing and testing procedure for digital controller design is proposed using the concept of Hardware-In- The-Loop (HIL). Some of the control loop components are real hardware components and thc others are simulated. First, the whole system is modeled and tested by Real- Time Simulation (RTS) using conventional simulation techniques such as MATLAB / SIMULINK. Second the Hardware-in-the-Ioop simulation is tested using Real-Time Windows Target in MATLAB and Visual C++. The control parts are included as hardware components which are the reactor control rod and its drivers. Two kinds of controllers are studied, Proportional derivative (PD) and Fuzzy controller, An experimental setup for the hardware used in HIL concept for the control of the nuclear research reactor has been realized. Experimental results are obtained and compared with the simulation results. The experimental results indicate the validation of HIL method in this domain

  17. QFT Based Robust Positioning Control of the PMSM Using Automatic Loop Shaping with Teaching Learning Optimization

    Directory of Open Access Journals (Sweden)

    Nitish Katal

    2016-01-01

    Full Text Available Automation of the robust control system synthesis for uncertain systems is of great practical interest. In this paper, the loop shaping step for synthesizing quantitative feedback theory (QFT based controller for a two-phase permanent magnet stepper motor (PMSM has been automated using teaching learning-based optimization (TLBO algorithm. The QFT controller design problem has been posed as an optimization problem and TLBO algorithm has been used to minimize the proposed cost function. This facilitates designing low-order fixed-structure controller, eliminates the need of manual loop shaping step on the Nichols charts, and prevents the overdesign of the controller. A performance comparison of the designed controller has been made with the classical PID tuning method of Ziegler-Nichols and QFT controller tuned using other optimization algorithms. The simulation results show that the designed QFT controller using TLBO offers robust stability, disturbance rejection, and proper reference tracking over a range of PMSM’s parametric uncertainties as compared to the classical design techniques.

  18. Pilot-in-the-Loop Analysis of Propulsive-Only Flight Control Systems

    Science.gov (United States)

    Chou, Hwei-Lan; Biezad, Daniel J.

    1996-01-01

    Longitudinal control system architectures are presented which directly couple flight stick motions to throttle commands for a multi-engine aircraft. This coupling enables positive attitude control with complete failure of the flight control system. The architectures chosen vary from simple feedback gains to classical lead-lag compensators with and without prefilters. Each architecture is reviewed for its appropriateness for piloted flight. The control systems are then analyzed with pilot-in-the-loop metrics related to bandwidth required for landing. Results indicate that current and proposed bandwidth requirements should be modified for throttles only flight control. Pilot ratings consistently showed better ratings than predicted by analysis. Recommendations are made for more robust design and implementation. The use of Quantitative Feedback Theory for compensator design is discussed. Although simple and effective augmented control can be achieved in a wide variety of failed configurations, a few configuration characteristics are dominant for pilot-in-the-loop control. These characteristics will be tested in a simulator study involving failed flight controls for a multi-engine aircraft.

  19. Motorized CPM/CAM physiotherapy device with sliding-mode Fuzzy Neural Network control loop.

    Science.gov (United States)

    Ho, Hung-Jung; Chen, Tien-Chi

    2009-11-01

    Continuous passive motion (CPM) and controllable active motion (CAM) physiotherapy devices promote rehabilitation of damaged joints. This paper presents a computerized CPM/CAM system that obviates the need for mechanical resistance devices such as springs. The system is controlled by a computer which performs sliding-mode Fuzzy Neural Network (FNN) calculations online. CAM-type resistance force is generated by the active performance of an electric motor which is controlled so as to oppose the motion of the patient's leg. A force sensor under the patient's foot on the device pedal provides data for feedback in a sliding-mode FNN control loop built around the motor. Via an active impedance control feedback system, the controller drives the motor to behave similarly to a damped spring by generating and controlling the amplitude and direction of the pedal force in relation to the patient's leg. Experiments demonstrate the high sensitivity and speed of the device. The PC-based feedback nature of the control loop means that sophisticated auto-adaptable CPM/CAM custom-designed physiotherapy becomes possible. The computer base also allows extensive data recording, data analysis and network-connected remote patient monitoring.

  20. An open-closed-loop iterative learning control approach for nonlinear switched systems with application to freeway traffic control

    Science.gov (United States)

    Sun, Shu-Ting; Li, Xiao-Dong; Zhong, Ren-Xin

    2017-10-01

    For nonlinear switched discrete-time systems with input constraints, this paper presents an open-closed-loop iterative learning control (ILC) approach, which includes a feedforward ILC part and a feedback control part. Under a given switching rule, the mathematical induction is used to prove the convergence of ILC tracking error in each subsystem. It is demonstrated that the convergence of ILC tracking error is dependent on the feedforward control gain, but the feedback control can speed up the convergence process of ILC by a suitable selection of feedback control gain. A switched freeway traffic system is used to illustrate the effectiveness of the proposed ILC law.

  1. Development of a hardware-in- loop simulation platform for NPP main control systems

    Directory of Open Access Journals (Sweden)

    Liu Pengfei

    2017-01-01

    Full Text Available The simulation technology of the nuclear power plant are gradually applying to the nuclear power industry. However, most of the research on nuclear power plant simulation system only focus on pure computerized simulation at present, and it is difficult to fully display the characteristics of the simulating objects. In order to simulate the response characteristics of control system more really, a hardware-in-loop simulation platform of main control systems in the nuclear power plant has been developed in this paper. This simulation platform consists of thermal-hydraulic model, control and protection system model, physical DCS system and real-time interactive database. A physical industrial DCS system has been coupled to this platform to simulate the main control systems in the NPP, which makes the simulation result much closer to the actual control systems. The devoloped simulation platform has been validated by some steady and transient cases in this paper. This hardware-in-loop simulation platform can be used in the simulation and optimal design of NPP control systems. Furthermore, it can be used in the failure mode and effect analysis of the instrumentation and control systems in the nuclear power plant.

  2. Artificial Pancreas Device Systems for the Closed-Loop Control of Type 1 Diabetes

    Science.gov (United States)

    Trevitt, Sara; Simpson, Sue; Wood, Annette

    2015-01-01

    Background: Closed-loop artificial pancreas device (APD) systems are externally worn medical devices that are being developed to enable people with type 1 diabetes to regulate their blood glucose levels in a more automated way. The innovative concept of this emerging technology is that hands-free, continuous, glycemic control can be achieved by using digital communication technology and advanced computer algorithms. Methods: A horizon scanning review of this field was conducted using online sources of intelligence to identify systems in development. The systems were classified into subtypes according to their level of automation, the hormonal and glycemic control approaches used, and their research setting. Results: Eighteen closed-loop APD systems were identified. All were being tested in clinical trials prior to potential commercialization. Six were being studied in the home setting, 5 in outpatient settings, and 7 in inpatient settings. It is estimated that 2 systems may become commercially available in the EU by the end of 2016, 1 during 2017, and 2 more in 2018. Conclusions: There are around 18 closed-loop APD systems progressing through early stages of clinical development. Only a few of these are currently in phase 3 trials and in settings that replicate real life. PMID:26589628

  3. Closed-loop focal plane wavefront control with the SCExAO instrument

    Science.gov (United States)

    Martinache, Frantz; Jovanovic, Nemanja; Guyon, Olivier

    2016-09-01

    Aims: This article describes the implementation of a focal plane based wavefront control loop on the high-contrast imaging instrument SCExAO (Subaru Coronagraphic Extreme Adaptive Optics). The sensor relies on the Fourier analysis of conventional focal-plane images acquired after an asymmetric mask is introduced in the pupil of the instrument. Methods: This absolute sensor is used here in a closed-loop to compensate for the non-common path errors that normally affects any imaging system relying on an upstream adaptive optics system.This specific implementation was used to control low-order modes corresponding to eight zernike modes (from focus to spherical). Results: This loop was successfully run on-sky at the Subaru Telescope and is used to offset the SCExAO deformable mirror shape used as a zero-point by the high-order wavefront sensor. The paper details the range of errors this wavefront-sensing approach can operate within and explores the impact of saturation of the data and how it can be bypassed, at a cost in performance. Conclusions: Beyond this application, because of its low hardware impact, the asymmetric pupil Fourier wavefront sensor (APF-WFS) can easily be ported in a wide variety of wavefront sensing contexts, for ground- as well space-borne telescopes, and for telescope pupils that can be continuous, segmented or even sparse. The technique is powerful because it measures the wavefront where it really matters, at the level of the science detector.

  4. Dynamic control of modeled tonic-clonic seizure states with closed-loop stimulation

    Directory of Open Access Journals (Sweden)

    Bryce eBeverlin II

    2013-02-01

    Full Text Available Seizure control using deep brain stimulation (DBS provides an alternative therapy to patients with intractable and drug resistant epilepsy. This paper presents novel DBS stimulus protocols to disrupt seizures. Two protocols are presented: open-loop stimulation and a closed-loop feedback system utilizing measured firing rates to adjust stimulus frequency. Stimulation suppression is demonstrated in a computational model using 3000 excitatory Morris-Lecar model neurons connected with depressing synapses. Cells are connected using second order network topology to simulate network topologies measured in cortical networks. The network spontaneously switches from tonic to clonic as synaptic strengths and tonic input to the neurons decreases. To this model we add periodic stimulation pulses to simulate DBS. Periodic forcing can synchronize or desynchronize an oscillating population of neurons, depending on the stimulus frequency and amplitude. Therefore, it is possible to either extend or truncate the tonic or clonic phases of the seizure. Stimuli applied at the firing rate of the neuron generally synchronize the population while stimuli slightly slower than the firing rate prevent synchronization. We present an adaptive stimulation algorithm that measures the firing rate of a neuron and adjusts the stimulus to maintain a relative stimulus frequency to firing frequency and demonstrate it in a computational model of a tonic-clonic seizure. This adaptive algorithm can affect the duration of the tonic phase using much smaller stimulus amplitudes than the open-loop control.

  5. Feedforward control of a closed-loop piezoelectric translation stage for atomic force microscope.

    Science.gov (United States)

    Li, Yang; Bechhoefer, John

    2007-01-01

    Simple feedforward ideas are shown to lead to a nearly tenfold increase in the effective bandwidth of a closed-loop piezoelectric positioning stage used in scanning probe microscopy. If the desired control signal is known in advance, the feedforward filter can be acausal: the information about the future can be used to make the output of the stage have almost no phase lag with respect to the input. This keeps in register the images assembled from right and left scans. We discuss the design constraints imposed by the need for the feedforward filter to work robustly under a variety of circumstances. Because the feedforward needs only to modify the input signal, it can be added to any piezoelectric stage, whether closed or open loop.

  6. A Highly Robust Single-Loop Current Control Scheme for Grid-Connected Inverter with an Improved LCCL Filter Configuration

    DEFF Research Database (Denmark)

    Pan, Donghua; Ruan, Xinbo; Wang, Xiongfei

    2018-01-01

    Single-loop current control is an attractive scheme for the LCL-type grid-connected inverter due to its simplicity and low cost. However, conventional single-loop control schemes, which command either the inverter current or the grid current, are subject to the specific resonance frequency regions....... The weighted average current control, which splits the filter capacitor into two parts (in form of an LCCL filter) and commands the current flowing between these two parts, is independent of the resonance frequency, but on the other hand, it is limited by the poor sensitivity to the grid impedance variation...... and weak stability in the grid current. These limitations are comprehensively explained in this paper and then addressed by identifying that the single-loop weighted average current control is equivalent to the dual-loop grid current control with an inherent capacitor current active damping. By tuning...

  7. Control of Stochastic Master Equation Models of Genetic Regulatory Networks by Approximating Their Average Behavior

    Science.gov (United States)

    Umut Caglar, Mehmet; Pal, Ranadip

    2010-10-01

    The central dogma of molecular biology states that ``information cannot be transferred back from protein to either protein or nucleic acid.'' However, this assumption is not exactly correct in most of the cases. There are a lot of feedback loops and interactions between different levels of systems. These types of interactions are hard to analyze due to the lack of data in the cellular level and probabilistic nature of interactions. Probabilistic models like Stochastic Master Equation (SME) or deterministic models like differential equations (DE) can be used to analyze these types of interactions. SME models based on chemical master equation (CME) can provide detailed representation of genetic regulatory system, but their use is restricted by the large data requirements and computational costs of calculations. The differential equations models on the other hand, have low calculation costs and much more adequate to generate control procedures on the system; but they are not adequate to investigate the probabilistic nature of interactions. In this work the success of the mapping between SME and DE is analyzed, and the success of a control policy generated by DE model with respect to SME model is examined. Index Terms--- Stochastic Master Equation models, Differential Equation Models, Control Policy Design, Systems biology

  8. Controlling fuel costs: Procurement strategies and regulatory standards

    International Nuclear Information System (INIS)

    Einhorn, H.A.; Levi, B.I.

    1992-01-01

    Since the oil price shocks and inflation of the 1970s, regulatory authorities and utilities have devoted considerable attention to controlling energy costs while maintaining reliable service. Although much of this concern has been directed towards capital cost containment, increasing scrutiny has been applied to a broad range of variable costs, especially to fuel procurement expenditures. With some 40% to 65% of the electric utility industry's annual operation and maintenance expenses paid to secure fuel supplies, even a small difference in fuel costs could have a substantial impact on costs to ratepayers. This increased attention to fuel cost containment can be expected to intensify as implementation of the 1990 amendments to the Clean Air Act affects fuel purchase decisions. To assure that fuel is purchased in a responsible and cost-effective manner, some state jurisdictions have initiated periodic reviews (audits) of the procurement practices that electric utilities follow when purchasing fuel. While a utility must demonstrate how it purchases fuel, there is wide variation in interest and scope of audits among jurisdictions. In this paper, the authors review: (1) the regulatory environment within which fuel procurement and audits occur, and (2) some particularly controversial issues that will receive increasing attention as the practice of conducting fuel procurement audits spreads

  9. Workshop on rules for exemption from regulatory control: Proceedings

    International Nuclear Information System (INIS)

    1989-04-01

    This conference report documents the proceedings of an International Workshop on the subject of exempting radiation sources and practices from regulatory control. The purpose of the workshop was to provide national regulatory authorities an opportunity to exchange information on their respective approaches and practices involving exemptions and to enhance international understanding and cooperation on the derivation and practical application of the underlying principles. In addition, input from the workshop was intended to assist the NRC in the development of a policy statement on this issue. The workshop was divided into five sessions. During the first four sessions, papers were presented which defined the relative terms and concepts, outlined the national situations and approaches to the establishment and development of exemption rules, identified and discussed the existing issues, and gave the status of the international guidelines on exemption rules. The fifth session was devoted to summarizing the workshop and identifying the areas of consensus, the outstanding issues and the areas for future work. Individual papers were processed separately for the data base

  10. Dual RNA regulatory control of a Staphylococcus aureus virulence factor.

    Science.gov (United States)

    Chabelskaya, Svetlana; Bordeau, Valérie; Felden, Brice

    2014-04-01

    In pathogens, the accurate programming of virulence gene expression is essential for infection. It is achieved by sophisticated arrays of regulatory proteins and ribonucleic acids (sRNAs), but in many cases their contributions and connections are not yet known. Based on genetic, biochemical and structural evidence, we report that the expression pattern of a Staphylococcus aureus host immune evasion protein is enabled by the collaborative actions of RNAIII and small pathogenicity island RNA D (SprD). Their combined expression profiles during bacterial growth permit early and transient synthesis of Sbi to avoid host immune responses. Together, these two sRNAs use antisense mechanisms to monitor Sbi expression at the translational level. Deletion analysis combined with structural analysis of RNAIII in complex with its novel messenger RNA (mRNA) target indicate that three distant RNAIII domains interact with distinct sites of the sbi mRNA and that two locations are deep in the sbi coding region. Through distinct domains, RNAIII lowers production of two proteins required for avoiding innate host immunity, staphylococcal protein A and Sbi. Toeprints and in vivo mutational analysis reveal a novel regulatory module within RNAIII essential for attenuation of Sbi translation. The sophisticated translational control of mRNA by two differentially expressed sRNAs ensures supervision of host immune escape by a major pathogen.

  11. Validation of gamma irradiator controls for quality and regulatory compliance

    International Nuclear Information System (INIS)

    Harding, R.B.; Pinteric, F.J.A.

    1995-01-01

    Since 1978 the U.S. Food and Drug Administration (FDA) has had both the legal authority and the Current Good Manufacturing Practice (CGMP) regulations in place to require irradiator owners who process medical devices to produce evidence of Irradiation Process Validation. One of the key components of Irradiation Process Validation is the validation of the irradiator controls. However, it is only recently that FDA audits have focused on this component of the process validation. What is Irradiator Control System Validation? What constitutes evidence of control? How do owners obtain evidence? What is the irradiator supplier's role in validation? How does the ISO 9000 Quality Standard relate to the FDA's CGMP requirement for evidence of Control System Validation? This paper presents answers to these questions based on the recent experiences of Nordion's engineering and product management staff who have worked with several US-based irradiator owners. This topic - Validation of Irradiator Controls - is a significant regulatory compliance and operations issues within the irradiator suppliers' and users' community. (author)

  12. Hardware-in-the-loop simulation of the EAST PF converter for PF control system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaojiao, E-mail: chenxj@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science (ASIPP), P.O. Box 1126, Hefei, Anhui Province 230031 (China); Chinese University of Science and Technology, Hefei, Anhui Province 230022 (China); Fu, Peng [Institute of Plasma Physics, Chinese Academy of Science (ASIPP), P.O. Box 1126, Hefei, Anhui Province 230031 (China); Chinese University of Science and Technology, Hefei, Anhui Province 230022 (China); Huang, Liansheng, E-mail: huangls@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science (ASIPP), P.O. Box 1126, Hefei, Anhui Province 230031 (China); Gao, Ge; He, Shiying [Institute of Plasma Physics, Chinese Academy of Science (ASIPP), P.O. Box 1126, Hefei, Anhui Province 230031 (China)

    2016-11-15

    Highlights: • The hardware in the loop simulation of the EAST PF system is presented. • The control functions and the protection logic have been tested and verified. • The major faults could be avoided and commissioning time could be saved on site. - Abstract: The EAST poloidal field (PF) control system was upgraded in 2015 and the new system has been in use for the 2015 EAST campaign. This paper presents the implementation of a hardware-in-the-loop (HIL) simulation platform of the EAST PF converter system based on the RT-LAB simulation environment, which was used to improve and evaluate the performance of the real controller. The EAST PF power supply system and its operational modes are presented in this paper. The experiments on HIL simulation platform show that the control algorithms and the over current protection of the controller meet the design requirements well. In addition, the effectiveness of the designed control system has been verified by actual application during the EAST campaign at 2015 for six months.

  13. Hardware-in-the-loop simulation of the EAST PF converter for PF control system upgrade

    International Nuclear Information System (INIS)

    Chen, Xiaojiao; Fu, Peng; Huang, Liansheng; Gao, Ge; He, Shiying

    2016-01-01

    Highlights: • The hardware in the loop simulation of the EAST PF system is presented. • The control functions and the protection logic have been tested and verified. • The major faults could be avoided and commissioning time could be saved on site. - Abstract: The EAST poloidal field (PF) control system was upgraded in 2015 and the new system has been in use for the 2015 EAST campaign. This paper presents the implementation of a hardware-in-the-loop (HIL) simulation platform of the EAST PF converter system based on the RT-LAB simulation environment, which was used to improve and evaluate the performance of the real controller. The EAST PF power supply system and its operational modes are presented in this paper. The experiments on HIL simulation platform show that the control algorithms and the over current protection of the controller meet the design requirements well. In addition, the effectiveness of the designed control system has been verified by actual application during the EAST campaign at 2015 for six months.

  14. H∞ Loop Shaping Control of Input Saturated Systems with Norm-Bounded Parametric Uncertainty

    Directory of Open Access Journals (Sweden)

    Renan Lima Pereira

    2015-01-01

    Full Text Available This paper proposes a gain-scheduling control design strategy for a class of linear systems with the presence of both input saturation constraints and norm-bounded parametric uncertainty. LMI conditions are derived in order to obtain a gain-scheduled controller that ensures the robust stability and performance of the closed loop system. The main steps to obtain such a controller are given. Differently from other gain-scheduled approaches in the literature, this one focuses on the problem of H∞ loop shaping control design with input saturation nonlinearity and norm-bounded uncertainty to reduce the effect of the disturbance input on the controlled outputs. Here, the design problem has been formulated in the four-block H∞ synthesis framework, in which it is possible to describe the parametric uncertainty and the input saturation nonlinearity as perturbations to normalized coprime factors of the shaped plant. As a result, the shaped plant is represented as a linear parameter-varying (LPV system while the norm-bounded uncertainty and input saturation are incorporated. This procedure yields a linear parameter-varying structure for the controller that ensures the stability of the polytopic LPV shaped plant from the vertex property. Finally, the effectiveness of the method is illustrated through application to a physical system: a VTOL “vertical taking-off landing” helicopter.

  15. Model-based closed-loop glucose control in type 1 diabetes

    DEFF Research Database (Denmark)

    Schmidt, Signe; Boiroux, Dimitri; Duun-Henriksen, Anne Katrine

    2013-01-01

    To improve type 1 diabetes mellitus (T1DM) management, we developed a model predictive control (MPC) algorithm for closed-loop (CL) glucose control based on a linear second-order deterministic-stochastic model. The deterministic part of the model is specified by three patient-specific parameters......: insulin sensitivity factor, insulin action time, and basal insulin infusion rate. The stochastic part is identical for all patients but identified from data from a single patient. Results of the first clinical feasibility test of the algorithm are presented....

  16. A review of the MIT experiments on the closed-loop digital control of reactor power

    International Nuclear Information System (INIS)

    Bernard, J.A.

    1989-01-01

    In this paper a review is provided of certain major experiments conducted from 1985 to 1988 as part of the MIT program on the development and demonstration of advanced technologies for the closed-loop digital control of nuclear reactors. Included are demonstrations of the supervisory control of neutronic power using an alternate formulation of the dynamic period equation, the use of the MIT-SNL Period-Generated Minimum Time Control Laws for the time-optimal control of neutronic power, and the evaluation of predictive displays as an operator aid. The significance of each of these advances is discussed in terms of the overall development of a multi-tiered controller that includes supervisory algorithms, predictive control laws, and automated reasoning

  17. A Versatile Method to Design Stem-Loop Primer-Based Quantitative PCR Assays for Detecting Small Regulatory RNA Molecules

    OpenAIRE

    Czimmerer, Zsolt; Hulvely, Julianna; Simandi, Zoltan; Varallyay, Eva; Havelda, Zoltan; Szabo, Erzsebet; Varga, Attila; Dezso, Balazs; Balogh, Maria; Horvath, Attila; Domokos, Balint; Torok, Zsolt; Nagy, Laszlo; Balint, Balint L.

    2013-01-01

    Short regulatory RNA-s have been identified as key regulators of gene expression in eukaryotes. They have been involved in the regulation of both physiological and pathological processes such as embryonal development, immunoregulation and cancer. One of their relevant characteristics is their high stability, which makes them excellent candidates for use as biomarkers. Their number is constantly increasing as next generation sequencing methods reveal more and more details of their synthesis. T...

  18. A versatile method to design stem-loop primer-based quantitative PCR assays for detecting small regulatory RNA molecules.

    Directory of Open Access Journals (Sweden)

    Zsolt Czimmerer

    Full Text Available Short regulatory RNA-s have been identified as key regulators of gene expression in eukaryotes. They have been involved in the regulation of both physiological and pathological processes such as embryonal development, immunoregulation and cancer. One of their relevant characteristics is their high stability, which makes them excellent candidates for use as biomarkers. Their number is constantly increasing as next generation sequencing methods reveal more and more details of their synthesis. These novel findings aim for new detection methods for the individual short regulatory RNA-s in order to be able to confirm the primary data and characterize newly identified subtypes in different biological conditions. We have developed a flexible method to design RT-qPCR assays that are very sensitive and robust. The newly designed assays were tested extensively in samples from plant, mouse and even human formalin fixed paraffin embedded tissues. Moreover, we have shown that these assays are able to quantify endogenously generated shRNA molecules. The assay design method is freely available for anyone who wishes to use a robust and flexible system for the quantitative analysis of matured regulatory RNA-s.

  19. Extending the Capabilities of Closed-loop Distributed Engine Control Simulations Using LAN Communication

    Science.gov (United States)

    Aretskin-Hariton, Eliot D.; Zinnecker, Alicia Mae; Culley, Dennis E.

    2014-01-01

    Distributed Engine Control (DEC) is an enabling technology that has the potential to advance the state-of-the-art in gas turbine engine control. To analyze the capabilities that DEC offers, a Hardware-In-the-Loop (HIL) test bed is being developed at NASA Glenn Research Center. This test bed will support a systems-level analysis of control capabilities in closed-loop engine simulations. The structure of the HIL emulates a virtual test cell by implementing the operator functions, control system, and engine on three separate computers. This implementation increases the flexibility and extensibility of the HIL. Here, a method is discussed for implementing these interfaces by connecting the three platforms over a dedicated Local Area Network (LAN). This approach is verified using the Commercial Modular Aero-Propulsion System Simulation 40k (C-MAPSS40k), which is typically implemented on one computer. There are marginal differences between the results from simulation of the typical and the three-computer implementation. Additional analysis of the LAN network, including characterization of network load, packet drop, and latency, is presented. The three-computer setup supports the incorporation of complex control models and proprietary engine models into the HIL framework.

  20. Distributed flow sensing for closed-loop speed control of a flexible fish robot.

    Science.gov (United States)

    Zhang, Feitian; Lagor, Francis D; Yeo, Derrick; Washington, Patrick; Paley, Derek A

    2015-10-23

    Flexibility plays an important role in fish behavior by enabling high maneuverability for predator avoidance and swimming in turbulent flow. This paper presents a novel flexible fish robot equipped with distributed pressure sensors for flow sensing. The body of the robot is molded from soft, hyperelastic material, which provides flexibility. Its Joukowski-foil shape is conducive to modeling the fluid analytically. A quasi-steady potential-flow model is adopted for real-time flow estimation, whereas a discrete-time vortex-shedding flow model is used for higher-fidelity simulation. The dynamics for the flexible fish robot yield a reduced model for one-dimensional swimming. A recursive Bayesian filter assimilates pressure measurements to estimate flow speed, angle of attack, and foil camber. The closed-loop speed-control strategy combines an inverse-mapping feedforward controller based on an average model derived for periodic actuation of angle-of-attack and a proportional-integral feedback controller utilizing the estimated flow information. Simulation and experimental results are presented to show the effectiveness of the estimation and control strategy. The paper provides a systematic approach to distributed flow sensing for closed-loop speed control of a flexible fish robot by regulating the flapping amplitude.

  1. MULTI-LOOP CONTROL DESIGN IN MULTIVARIABLE (2X2 CONTINUOUS STIRRED TANK REACTOR

    Directory of Open Access Journals (Sweden)

    Abdul Wahid

    2015-06-01

    Full Text Available With this study, the design and tuning of multi-loop for multivariable (2x2 CSTR will be made in order to achieve optimum CSTR control performance. This study used Bequette model reactor and MATLAB software and is expected to be able to cope with disturbances in the reactor so that the reactor system is able to stabilize quickly despite the distractions. In this study, the design will be made using multi-loop approach, along with PI controller as the next step. Then, BLT and auto-tune tuning method will be used in PI controller and given disturbances to both of tuning method. The controller performances are then compared. Results of the study are then analyzed for discussions and conclusions. Results from this study have shown that in terms of disturbance rejection, BLT is better than auto-tune based on comparison between both of controller performances. For IAE for the case of temperature, BLT is 30% better than auto-tune, but it is almost the same for the case of concentration. For settling time for the case of concentration, BLT is 30% better than auto-tune, and for the case of temperature, BLT is 18% better than auto-tune. For rise time for the case of concentration and temperature, BLT is 30% better than auto-tune.

  2. Wireless Magnetic-Based Closed-Loop Control of Self-Propelled Microjets

    Science.gov (United States)

    Khalil, Islam S. M.; Magdanz, Veronika; Sanchez, Samuel; Schmidt, Oliver G.; Misra, Sarthak

    2014-01-01

    In this study, we demonstrate closed-loop motion control of self-propelled microjets under the influence of external magnetic fields. We control the orientation of the microjets using external magnetic torque, whereas the linear motion towards a reference position is accomplished by the thrust and pulling magnetic forces generated by the ejecting oxygen bubbles and field gradients, respectively. The magnetic dipole moment of the microjets is characterized using the U-turn technique, and its average is calculated to be 1.310−10 A.m2 at magnetic field and linear velocity of 2 mT and 100 µm/s, respectively. The characterized magnetic dipole moment is used in the realization of the magnetic force-current map of the microjets. This map in turn is used for the design of a closed-loop control system that does not depend on the exact dynamical model of the microjets and the accurate knowledge of the parameters of the magnetic system. The motion control characteristics in the transient- and steady-states depend on the concentration of the surrounding fluid (hydrogen peroxide solution) and the strength of the applied magnetic field. Our control system allows us to position microjets at an average velocity of 115 m/s, and within an average region-of-convergence of 365 m. PMID:24505244

  3. Closed-loop control of spinal cord stimulation to restore hand function after paralysis

    Directory of Open Access Journals (Sweden)

    Jonas B Zimmermann

    2014-05-01

    Full Text Available As yet, no cure exists for upper-limb paralysis resulting from the damage to motor pathways after spinal cord injury or stroke. Recently, neural activity from the motor cortex of paralyzed individuals has been used to control the movements of a robot arm but restoring function to patients’ actual limbs remains a considerable challenge. Previously we have shown that electrical stimulation of the cervical spinal cord in anesthetized monkeys can elicit functional upper-limb movements like reaching and grasping. Here we show that stimulation can be controlled using cortical activity in awake animals to bypass disruption of the corticospinal system, restoring their ability to perform a simple upper-limb task. Monkeys were trained to grasp and pull a spring-loaded handle. After temporary paralysis of the hand was induced by reversible inactivation of primary motor cortex using muscimol, grasp-related single-unit activity from the ventral premotor cortex was converted into stimulation patterns delivered in real-time to the cervical spinal grey matter. During periods of closed-loop stimulation, task-modulated electromyogram, movement amplitude and task success rate were improved relative to interleaved control periods without stimulation. In some sessions, single motor unit activity from weakly active muscles was also used successfully to control stimulation. These results are the first use of a neural prosthesis to improve the hand function of primates after motor cortex disruption, and demonstrate the potential for closed-loop cortical control of spinal cord stimulation to reanimate paralyzed limbs.

  4. Power flow control based solely on slow feedback loop for heart pump applications.

    Science.gov (United States)

    Wang, Bob; Hu, Aiguo Patrick; Budgett, David

    2012-06-01

    This paper proposes a new control method for regulating power flow via transcutaneous energy transfer (TET) for implantable heart pumps. Previous work on power flow controller requires a fast feedback loop that needs additional switching devices and resonant capacitors to be added to the primary converter. The proposed power flow controller eliminates these additional components, and it relies solely on a slow feedback loop to directly drive the primary converter to meet the heart pump power demand and ensure zero voltage switching. A controlled change in switching frequency varies the resonant tank shorting period of a current-fed push-pull resonant converter, thus changing the magnitude of the primary resonant voltage, as well as the tuning between primary and secondary resonant tanks. The proposed controller has been implemented successfully using an analogue circuit and has reached an end-to-end power efficiency of 79.6% at 10 W with a switching frequency regulation range of 149.3 kHz to 182.2 kHz.

  5. Closed-loop Identification for Control of Linear Parameter Varying Systems

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    2014-01-01

    , closed- loop system identification is more difficult than open-loop identification. In this paper we prove that the so-called Hansen Scheme, a technique known from linear time-invariant systems theory for transforming closed-loop system identification problems into open-loop-like problems, can...

  6. Robust Model-based Control of Open-loop Unstable Processes

    International Nuclear Information System (INIS)

    Emad, Ali

    1999-01-01

    This paper addresses the development of new formulations for estimating modeling errors or unmeasured disturbances to be used in Model Predictive Control (MPC) algorithms during open-loop prediction. Two different formulations were developed in this paper. One is used in MPC that directly utilizes linear models and the other in MPC that utilizes non-linear models. These estimation techniques were utilized to provide robust performance for MPC algorithms when the plant is open-loop unstable and under the influence of modeling error and/or unmeasured disturbances. For MPC that utilizes a non-linear model, the estimation technique is formulated as a fixed small size on-line optimization problem, while for linear MPC, the unmeasured disturbances are estimated via a proposed linear disturbance model. The disturbance model coefficients are identified on-line from historical estimates of plant-model mismatch. The effectiveness of incorporating these proposed estimation techniques into MPC is tested through simulated implementation on non-linear unstable exothermic fluidized bed reactor. Closed-loop simulations proved the capability of the proposed estimation methods to stabilize and, thereby, improve the MPC performance in such cases. (Author)

  7. Regulatory control of radioactivity and nuclear fuel cycle in Canada

    International Nuclear Information System (INIS)

    Hamel, P.E.; Jennekens, J.H.

    1977-01-01

    The mining of pitchblende for the extraction of radium some four decades ago resulted in a largely unwanted by-product, uranium, which set the stage for Canada to be one of the first countires in the world to embark upon a nuclear energy program. From this somewhat unusual beginning, the Canadian program expanded beyond mining of uranium-bearing ores to include extensive research and development in the field of radio-isotope applications, research and power reactors, nuclear-fuel conversion and fabrication facilities, heavy-water production plants and facilities for the management of radioactive wastes. As in the case of any major technological development, nuclear energy poses certain risks on the part of those directly engaged in the industry and on the part of the general public. What characterizes these risks is not so much their physical nature as the absence of long-term experience and the confidence resulting from it. The early development of regulatory controls in the nuclear field in Canada was very much influenced by security considerations but subsequently evolved to include radiological protection and safety requirements commensurate with the expanding application of nuclear energy to a wide spectrum of peaceful uses. A review of Canadian nuclear regulatory experience will reveal that the risks posed by the peaceful uses of nuclear energy can be controlled in such a manner as to ensure a high level of safety. Recent events and development have shown however that emphasis on the risks associated with low-probability, high-consequence events must not be allowed to mask the importance of health and safety measures covering the entire fuel cycle

  8. A statistical learning strategy for closed-loop control of fluid flows

    Science.gov (United States)

    Guéniat, Florimond; Mathelin, Lionel; Hussaini, M. Yousuff

    2016-12-01

    This work discusses a closed-loop control strategy for complex systems utilizing scarce and streaming data. A discrete embedding space is first built using hash functions applied to the sensor measurements from which a Markov process model is derived, approximating the complex system's dynamics. A control strategy is then learned using reinforcement learning once rewards relevant with respect to the control objective are identified. This method is designed for experimental configurations, requiring no computations nor prior knowledge of the system, and enjoys intrinsic robustness. It is illustrated on two systems: the control of the transitions of a Lorenz'63 dynamical system, and the control of the drag of a cylinder flow. The method is shown to perform well.

  9. Closed-loop control of grasping with a myoelectric hand prosthesis: which are the relevant feedback variables for force control?

    Science.gov (United States)

    Ninu, Andrei; Dosen, Strahinja; Muceli, Silvia; Rattay, Frank; Dietl, Hans; Farina, Dario

    2014-09-01

    In closed-loop control of grasping by hand prostheses, the feedback information sent to the user is usually the actual controlled variable, i.e., the grasp force. Although this choice is intuitive and logical, the force production is only the last step in the process of grasping. Therefore, this study evaluated the performance in controlling grasp strength using a hand prosthesis operated through a complete grasping sequence while varying the feedback variables (e.g., closing velocity, grasping force), which were provided to the user visually or through vibrotactile stimulation. The experiments were conducted on 13 volunteers who controlled the Otto Bock Sensor Hand Speed prosthesis. Results showed that vibrotactile patterns were able to replace the visual feedback. Interestingly, the experiments demonstrated that direct force feedback was not essential for the control of grasping force. The subjects were indeed able to control the grip strength, predictively, by estimating the grasping force from the prosthesis velocity of closing. Therefore, grasping without explicit force feedback is not completely blind, contrary to what is usually assumed. In our study we analyzed grasping with a specific prosthetic device, but the outcomes are also applicable for other devices, with one or more degrees-of-freedom. The necessary condition is that the electromyography (EMG) signal directly and proportionally controls the velocity/grasp force of the hand, which is a common approach among EMG controlled prosthetic devices. The results provide important indications on the design of closed-loop EMG controlled prosthetic systems.

  10. Regulatory control of nuclear safety in Finland. Annual report 1999

    International Nuclear Information System (INIS)

    Tossavainen, K.

    2000-06-01

    This report concerns the regulatory control of nuclear energy in Finland in 1999. Its submission to the Ministry of Trade and Industry by the Finnish Radiation and Nuclear Safety Authority (STUK) is stipulated in section 121 of the Nuclear Energy Decree. STUK's regulatory work was focused on the operation of the Finnish nuclear power plants as well as on nuclear waste management and safeguards of nuclear materials. The operation of the Finnish nuclear power plants was in compliance with the conditions set out in their operating licences and with current regulations, with the exception of some inadvertent deviations from the Technical Specifications. No plant events endangering the safe use of nuclear energy occurred. The individual doses of all nuclear power plant workers remained below the dose threshold. The collective dose of the workers was low, compared internationally, and did not exceed STUK's guidelines at either nuclear power plant. The radioactive releases were minor and the dose calculated on their basis for the most exposed individual in the vicinity of the plant was well below the limit established in a decision of the Council of State at both Loviisa and Olkiluoto nuclear power plants. STUK issued statements to the Ministry of Trade and Industry about the environmental impact assessment programme reports on the possible nuclear power plant projects at Olkiluoto and Loviisa and about the continued operation of the research reactor in Otaniemi, Espoo. A Y2k-related safety assessment of the Finnish nuclear power plants was completed in December. In nuclear waste management STUK's regulatory work was focused on spent fuel storage and final disposal plans as well as on the treatment, storage and final disposal of reactor waste. No events occurred in nuclear waste management that would have endangered safety. A statement was issued to the Ministry of Trade and Industry about an environmental impact assessment report on a proposed final disposal facility for

  11. Regulatory control of nuclear safety in Finland. Annual report 1999

    Energy Technology Data Exchange (ETDEWEB)

    Tossavainen, K. [ed.

    2000-06-01

    This report concerns the regulatory control of nuclear energy in Finland in 1999. Its submission to the Ministry of Trade and Industry by the Finnish Radiation and Nuclear Safety Authority (STUK) is stipulated in section 121 of the Nuclear Energy Decree. STUK's regulatory work was focused on the operation of the Finnish nuclear power plants as well as on nuclear waste management and safeguards of nuclear materials. The operation of the Finnish nuclear power plants was in compliance with the conditions set out in their operating licences and with current regulations, with the exception of some inadvertent deviations from the Technical Specifications. No plant events endangering the safe use of nuclear energy occurred. The individual doses of all nuclear power plant workers remained below the dose threshold. The collective dose of the workers was low, compared internationally, and did not exceed STUK's guidelines at either nuclear power plant. The radioactive releases were minor and the dose calculated on their basis for the most exposed individual in the vicinity of the plant was well below the limit established in a decision of the Council of State at both Loviisa and Olkiluoto nuclear power plants. STUK issued statements to the Ministry of Trade and Industry about the environmental impact assessment programme reports on the possible nuclear power plant projects at Olkiluoto and Loviisa and about the continued operation of the research reactor in Otaniemi, Espoo. A Y2k-related safety assessment of the Finnish nuclear power plants was completed in December. In nuclear waste management STUK's regulatory work was focused on spent fuel storage and final disposal plans as well as on the treatment, storage and final disposal of reactor waste. No events occurred in nuclear waste management that would have endangered safety. A statement was issued to the Ministry of Trade and Industry about an environmental impact assessment report on a proposed final

  12. Operation manual for the core flow test loop zone power-supply controller

    Energy Technology Data Exchange (ETDEWEB)

    Harper, R.E.

    1981-11-01

    The core flow test loop, which is part of the Gas-Cooled Fast Breeder Reactor Program (GCFR) at ORNL, is a high-pressure, high-temperature, out-of-reactor helium circulation system that is being constructed to permit study of the performance at steady-state and transient conditions of simulated segments of core assemblies for a GCFR demonstration plant. The simulated core segments, which are divided into zones, contain electrical heating elements to simulate the heat generated by fission. To control the power which is applied to a zone, a novel multitapped transformer and zone power control system have been designed and built which satisfy stringent design criteria. The controller can match power output to demand to within better than +-1% over a 900:1 dynamic range and perform full-power transients within 1 s. The power is applied in such a way as to minimize the electromagnetic interference at the bandwidth of the loop instrumentation, and the controller incorporates several error detection techniques, making it inherently fail-safe. The operation manual describes the specifications, operating instructions, error detection capabilities, error recovery, troubleshooting, calibration and QA procedures, and maintenance requirements. Also included are sections on the theory of operation, circuitry description, and a complete set of schematics.

  13. Closed-loop feedback control for microfluidic systems through automated capacitive fluid height sensing.

    Science.gov (United States)

    Soenksen, L R; Kassis, T; Noh, M; Griffith, L G; Trumper, D L

    2018-03-13

    Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to these sensing limitations. Here we present an optimized self-shielded coplanar capacitive sensor design and automated control system to provide submillimeter fluid-height resolution (∼250 μm) and control of small-scale open reservoirs without the need for direct fluid contact. Results from testing and validation of our optimized sensor and system also suggest that accurate fluid height information can be used to robustly characterize, calibrate and dynamically control a range of microfluidic systems with complex pumping mechanisms, even in cell culture conditions. Capacitive sensing technology provides a scalable and cost-effective way to enable continuous monitoring and closed-loop feedback control of fluid volumes in small-scale gravity-dominated wells in a variety of microfluidic applications.

  14. dc SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller

    International Nuclear Information System (INIS)

    Seppae, H.

    1992-01-01

    A low-noise SQUID readout electronics with a high slew rate and an automatic gain control feature has been developed. Flux noise levels of 5x10 -7 Φ 0 /√Hz at 1 kHz and 2x10 -6 Φ 0 /√Hz at 1 Hz have been measured with this readout scheme. The system tolerates sinusoidal disturbances having amplitudes up to 140 Φ 0 at 1 kHz without loosing lock. The electronics utilizes a cooled GaAs FET to control the cancellation of the voltage noise of the room temperature amplifier, a PI 3/2 controller to provide a high open-loop gain at low frequencies, and a square-wave flux and offset voltage modulation to enable automatic control of the noise reduction. The cutoff frequency of the flux-locked-loop is 300 kHz and the feedback gain is more than 130 dB at 10 Hz. (orig.)

  15. Robustness study of the pseudo open-loop controller for multiconjugate adaptive optics.

    Science.gov (United States)

    Piatrou, Piotr; Gilles, Luc

    2005-02-20

    Robustness of the recently proposed "pseudo open-loop control" algorithm against various system errors has been investigated for the representative example of the Gemini-South 8-m telescope multiconjugate adaptive-optics system. The existing model to represent the adaptive-optics system with pseudo open-loop control has been modified to account for misalignments, noise and calibration errors in deformable mirrors, and wave-front sensors. Comparison with the conventional least-squares control model has been done. We show with the aid of both transfer-function pole-placement analysis and Monte Carlo simulations that POLC remains remarkably stable and robust against very large levels of system errors and outperforms in this respect least-squares control. Approximate stability margins as well as performance metrics such as Strehl ratios and rms wave-front residuals averaged over a 1-arc min field of view have been computed for different types and levels of system errors to quantify the expected performance degradation.

  16. Effective Regulatory Control of Radioactive Sources in Taiwan

    International Nuclear Information System (INIS)

    Liu, W.; Yuan, C.; Fan, S.; Su, S.

    2004-01-01

    Since the incident of radioactively contaminated buildings first surfaced in Taiwan in 1992, efforts have been made by AEC (Atomic Energy Council) of Taiwan to prevent recurrence of similar incidents involving radioactive materials and to achieve effective regulatory control over radioactive sources. The most important milestone is when AEC began to enforce IRPA he Ionizing Radiation Protection Act with the promulgation of 18 relevant regulations on Feb. 1, 2003. In order to enhance accountability of radioactive material and equipment capable of producing ionizing radiation, AEC develops and begins implementing a RPCS Radiation Protection Control System which is a powerful tool in controlling radiation safety and security. In addition, AEC develops a monthly registration program via internet, an o n-line reporting system f or owners/operators of radioactive sources, to improve monitoring of sealed sources (in-use and not-in-use). The registration requirement applies to 469 licensees possessing about 3,000 sealed sources in Taiwan. Because of the threat of orphan sources, AEC has made great efforts in preventing their contamination of construction steel material by establishing and enforcing the RPMMPIRCB Regulation for Preventive Measures and Management Plans for Incident of Radioactively Contaminated Buildings. To comply with this regulation, all 19 of Taiwan's steel factories with melting furnace have installed portal-type radiation detection system to monitor incoming scrap metal. (Author)

  17. Regulatory inspection: a powerful tool to control industrial radioactive sources

    International Nuclear Information System (INIS)

    Silva, F.C.A. da; Leocadio, J.C.; Ramalho, A.T.

    2008-01-01

    An important contribution for Brazilian development, especially for the quality control of products, is the use of radiation sources by conventional industries. There are in Brazil roughly 3,000 radioactive sources spread out among 950 industries. The main industrial practices involved are: industrial radiography, industrial irradiators, industrial accelerators, well logging petroleum and nuclear gauges. More than 1,800 Radiation Protection Officers (RPOs) were qualified to work in these practices. The present work presents a brief description of the safety control over industrial radioactive installations performed by the Brazilian Regulatory Authority, i.e. the National Commission of Nuclear Energy (CNEN). This paper also describes the national system for radiation safety inspections, the regulation infrastructure and the national inventory of industrial installations. The inspections are based on specific indicators, and their periodicity depends on the risk and type of installation. The present work discusses some relevant aspects that must be considered during the inspections, in order to make the inspections more efficient in controlling the sources. One of these aspects regards the evaluation of the storage place for the sources, a very important parameter for preventing future risky situations. (author)

  18. Characteristics of pressure control system on PWR/PHWR in pile loop facility

    International Nuclear Information System (INIS)

    Sarwani; Hendro, P.; Suwoto; Sutrisno

    1998-01-01

    PWR/PHWR in-pile loop facility is used for testing of fuel element bundle which is correspond to the condition of power reactor operation. So, this facility is designed at 150 bar of pressure and 350 o C of temperature. Pressure control system is one of the components of the facility and it is equipped with 6 electrical heaters (30 KW), water spray, pressure and temperature monitors. The characterization test of pressure control system has been carried out with operating of 2 electrical heaters (10 KW). The K eff calculation value is different 5.2% from pressure in the pressure control system can be increased to 160 bar within 27 hours. After the system pressure reached the nominal pressure, the pressure control system was in the steady state condition

  19. EBR-II secondary sodium loop Plugging Temperature Indicator control system upgrade

    International Nuclear Information System (INIS)

    Carlson, R.B.; Gehrman, R.L.

    1995-01-01

    The Experimental Breeder Reactor II (EBR-II) secondary sodium coolant loop Plugging Temperature Indicator (PTI) control system was upgraded in 1993 to a real-time computer based system. This was done to improve control, to remove obsolete and high maintenance equipment, and to provide a graphical CRT based operator interface. A goal was to accomplish this inexpensively using small, reliable computer and display hardware with a minimum of purchased software. This paper describes the PTI system, the upgraded control system and its operator interface, and development methods and tools. The paper then assesses how well the system met its goals, discusses lessons learned and operational improvements noted, and provides some recommendations and suggestions on applying small real-time control systems of this type

  20. Operational techniques employed for the liquid sodium source term control loops

    International Nuclear Information System (INIS)

    Chulos, L.E.

    1976-01-01

    Four Source Term Control Loops (STCLs) have been designed, constructed, and placed into operation at the Hanford Engineering Development Laboratory (HEDL) as part of the Radioactivity Control Technology program. The data obtained are used to determine the corrosion and deposition of LMFBR materials, including corrosion product radionuclides, in a non-isothermal flowing sodium system. The paper discusses operation of the STCL Facilities and, in particular, the methods used for controlling the oxygen content of the liquid sodium. These methods include cold trapping techniques, hot trapping, seeding the cold traps with sodium oxide, and precipitating the oxygen in the cold trap in a controlled manner. Operational problems encountered with the STCL Facilities and the techniques for correcting these problems are also discussed

  1. Implantable electronics of a closed-loop system for controlling prosthetic hands

    Directory of Open Access Journals (Sweden)

    Nikas Antonios

    2017-09-01

    Full Text Available This paper presents the design of implantable electronics as a part of a system for prosthetic hand control. Purpose of the implant is the sensing of electrical signals originating from biological tissue and the actuation of the same, therefore closing the loop and allowing for an improved control of the prosthetic hand. The implant contains two integrated circuits for eight channel EMG monitoring and four channel stimulation, respectively. An on-board microcontroller allows for local pre-processing. All intracorporeal to extracorporeal communications are running through and are directed by the main processing platform. The external components of the control system include, in addition to the main processing and control platform, the inductive power transfer circuits and the pressure sensors for the sensory feedback. Different assembly and encapsulation options are taken into account for the implantable electronics and are unified in a single PCB design.

  2. [Individual, community, regulatory, and systemic approaches to tobacco control interventions].

    Science.gov (United States)

    Gorini, Giuseppe

    2011-01-01

    During the 60s and the 70s strategies for decreasing initiation or quitting have been developed, in order to find those with high success rates. Unfortunately, interventions with an individual approach involved few smokers, so their impact in decreasing smoking prevalence was limited. The socio-ecological model offers a theoretical framework to community interventions for smoking cessation developed during the 80s, in which smoking was considered not only an individual, but also a social problem. In the 80s and the 90s smoking cessation community trials were developed, such as the Community Intervention Trial for Smoking Cessation (COMMIT). Afterwards, policy interventions (price policy; smoking bans in public places; advertising bans; bans of sales to minors) were developed, such as the American Stop Smoking Intervention Study for Cancer Prevention (ASSIST). California has been the first State all over the world to develop a comprehensive Tobacco Control Program in 1988, becoming the place for an ever-conducted natural experiment. All policy interventions in tobacco control have been finally grouped together in the World Health Organization - Framework Convention on Tobacco Control (WHO-FCTC), the first Public Health Treaty. Study designs have changed, according to the individual, community, or regulatory approaches: the classical randomized controlled trials (RCTs), in which the sampling unit is the individual, have been carried out for the evaluation of smoking cessation treatments, whereas cluster RCTs, in which the sampling unit is the community, have been conducted for evaluating community interventions, such as COMMIT. Finally, quasi-experimental studies (before/after study; prospective cohorts, both with a control group), in which the observational unit is a State, have been used for evaluating tobacco control policies, such as ASSIST and the International Tobacco Control Policy Evaluation Project. Although the successes of the last 20 years, tobacco

  3. Strategy and Evaluation of Vehicle Collision Avoidance Control via Hardware-in-the-Loop Platform

    Directory of Open Access Journals (Sweden)

    Sin-Li Chen

    2016-11-01

    Full Text Available This paper proposes a novel control approach for vehicle collision avoidance of urban vehicles. For safe driving in urban environments, this paper presents both one-dimensional and two-dimensional solutions, which can be applied to the collision avoidance via steering assistance, automatic braking, and warning of collision. Strategies are verified under the software CarSim, and the experimental evaluations are carried out under the combination of CarSim with a hardware-in-the-loop platform. The results show the feasibility and effectiveness of the proposed algorithm on vehicle collision avoidance.

  4. Model-Based, Closed-Loop Control of PZT Creep for Cavity Ring-Down Spectroscopy.

    Science.gov (United States)

    McCartt, A D; Ognibene, T J; Bench, G; Turteltaub, K W

    2014-09-01

    Cavity ring-down spectrometers typically employ a PZT stack to modulate the cavity transmission spectrum. While PZTs ease instrument complexity and aid measurement sensitivity, PZT hysteresis hinders the implementation of cavity-length-stabilized, data-acquisition routines. Once the cavity length is stabilized, the cavity's free spectral range imparts extreme linearity and precision to the measured spectrum's wavelength axis. Methods such as frequency-stabilized cavity ring-down spectroscopy have successfully mitigated PZT hysteresis, but their complexity limits commercial applications. Described herein is a single-laser, model-based, closed-loop method for cavity length control.

  5. Design Research on Three-Phase PWM Rectifier Based on Double Closed Loop Control Technology

    Directory of Open Access Journals (Sweden)

    Guang Ya LIU

    2014-02-01

    Full Text Available Based on the high frequency of three-phase voltage source PWM rectifier, this paper established a mathematical model of three phase current inner ring and outer ring voltage, and put forward the setting method of three phase double closed loop control. Finally, it was verified through simulation. The experimental results show that Three-phase output of DC voltage is stable with the operation of regulating systems, the current flowing into the grid tends to be sinusoidal and power factor is close to 1, which greatly reduce the interference of harmonics on the grid, thus improve grid operation.

  6. Time Difference Amplifier with Robust Gain Using Closed-Loop Control

    Science.gov (United States)

    Nakura, Toru; Mandai, Shingo; Ikeda, Makoto; Asada, Kunihiro

    This paper presents a Time Difference Amplifier (TDA) that amplifies the input time difference into the output time difference. Cross coupled chains of variable delay cells with the same number of stages are applicable for TDA, and the gain is adjusted via the closed-loop control. The TDA was fabricated using 65nm CMOS and the measurement results show that the time difference gain is 4.78 at a nominal power supply while the designed gain is 4.0. The gain is stable enough to be less than 1.4% gain shift under ±10% power supply voltage fluctuation.

  7. A hardware-in-the-loop simulation platform for prototyping and testing of wind generator controllers

    Energy Technology Data Exchange (ETDEWEB)

    Paquin, J.N.; Dufour, C.; Belanger, J. [OPAL-RT Technologies Inc., Montreal, PQ (Canada)

    2008-07-01

    Engineers from different specialized fields need to be involved in meeting the growing demand for integrated renewable energy sources into existing power grids. The integration of distributed generation (DG) sources significantly changes the characteristics of an entire network and requires analysis of power quality, transient response to fault occurrences, protection coordination studies and controller interaction studies. Power electronic converters are a considerable challenge. Accurately simulating fast switching devices requires the use of very small time steps to solve the system's equations. Off-line simulation is often used in the field. However, it is time consuming if no precision compromise has been made on models. In addition, off-line simulation tools do not offer the wide range of possibilities available with state-of-the-art distributed real-time simulators that combine the efforts of control engineers and specialists from wind turbine manufacturers, who need to test their controllers using hardware-in-the-loop (HIL), together with those of network planning engineers from public utilities, who will conduct interconnection, interaction and protection studies. This paper focused on the prototyping and testing of DG controllers using hardware-in-the-loop simulation. The model was described and consisted of a 10-turbine wind farm connected to a single feeder, simulated using an eMEGAsim real-time simulator equipped with 8-processor cores. One of the wind turbines was controlled using an externally emulated controller. It was modeled and simulated using a dual-processor core real-time simulator, which interacted with the plant model via analog and fast digital inputs and outputs. The effectiveness of the technology was demonstrated by comparing fully numerical simulation results with an HIL-connected DFIG controller simulation. The sampling effect of the digital simulator was correctly compensated for. The simulator could be driven directly by real

  8. Physiological closed-loop control in intelligent oxygen therapy: A review.

    Science.gov (United States)

    Sanchez-Morillo, Daniel; Olaby, Osama; Fernandez-Granero, Miguel Angel; Leon-Jimenez, Antonio

    2017-07-01

    Oxygen therapy has become a standard care for the treatment of patients with chronic obstructive pulmonary disease and other hypoxemic chronic lung diseases. In current systems, manually continuous adjustment of O 2 flow rate is a time-consuming task, often unsuccessful, that requires experienced staff. The primary aim of this systematic review is to collate and report on the principles, algorithms and accuracy of autonomous physiological close-loop controlled oxygen devices as well to present recommendations for future research and studies in this area. A literature search was performed on medical database MEDLINE, engineering database IEEE-Xplore and wide-raging scientific databases Scopus and Web of Science. A narrative synthesis of the results was carried out. A summary of the findings of this review suggests that when compared to the conventional manual practice, the closed-loop controllers maintain higher saturation levels, spend less time below the target saturation, and save oxygen resources. Nonetheless, despite of their potential, autonomous oxygen therapy devices are scarce in real clinical applications. Robustness of control algorithms, fail-safe mechanisms, limited reliability of sensors, usability issues and the need for standardized evaluating methods of assessing risks can be among the reasons for this lack of matureness and need to be addressed before the wide spreading of a new generation of automatic oxygen devices. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Ground-based adaptive optics coronagraphic performance under closed-loop predictive control

    Science.gov (United States)

    Males, Jared R.; Guyon, Olivier

    2018-01-01

    The discovery of the exoplanet Proxima b highlights the potential for the coming generation of giant segmented mirror telescopes (GSMTs) to characterize terrestrial-potentially habitable-planets orbiting nearby stars with direct imaging. This will require continued development and implementation of optimized adaptive optics systems feeding coronagraphs on the GSMTs. Such development should proceed with an understanding of the fundamental limits imposed by atmospheric turbulence. Here, we seek to address this question with a semianalytic framework for calculating the postcoronagraph contrast in a closed-loop adaptive optics system. We do this starting with the temporal power spectra of the Fourier basis calculated assuming frozen flow turbulence, and then apply closed-loop transfer functions. We include the benefits of a simple predictive controller, which we show could provide over a factor of 1400 gain in raw point spread function contrast at 1 λ/D on bright stars, and more than a factor of 30 gain on an I=7.5 mag star such as Proxima. More sophisticated predictive control can be expected to improve this even further. Assuming a photon-noise limited observing technique such as high-dispersion coronagraphy, these gains in raw contrast will decrease integration times by the same large factors. Predictive control of atmospheric turbulence should therefore be seen as one of the key technologies that will enable ground-based telescopes to characterize terrestrial planets.

  10. Development of a hardware-in-loop attitude control simulator for a CubeSat satellite

    Science.gov (United States)

    Tapsawat, Wittawat; Sangpet, Teerawat; Kuntanapreeda, Suwat

    2018-01-01

    Attitude control is an important part in satellite on-orbit operation. It greatly affects the performance of satellites. Testing of an attitude determination and control subsystem (ADCS) is very challenging since it might require attitude dynamics and space environment in the orbit. This paper develops a low-cost hardware-in-loop (HIL) simulator for testing an ADCS of a CubeSat satellite. The simulator consists of a numerical simulation part, a hardware part, and a HIL interface hardware unit. The numerical simulation part includes orbital dynamics, attitude dynamics and Earth’s magnetic field. The hardware part is the real ADCS board of the satellite. The simulation part outputs satellite’s angular velocity and geomagnetic field information to the HIL interface hardware. Then, based on this information, the HIL interface hardware generates I2C signals mimicking the signals of the on-board rate-gyros and magnetometers and consequently outputs the signals to the ADCS board. The ADCS board reads the rate-gyro and magnetometer signals, calculates control signals, and drives the attitude actuators which are three magnetic torquers (MTQs). The responses of the MTQs sensed by a separated magnetometer are feedback to the numerical simulation part completing the HIL simulation loop. Experimental studies are conducted to demonstrate the feasibility and effectiveness of the simulator.

  11. Advanced ECCD based NTM control in closed-loop operation at ASDEX Upgrade (AUG)

    Science.gov (United States)

    Reich, Matthias; Barrera-Orte, Laura; Behler, Karl; Bock, Alexander; Giannone, Louis; Maraschek, Marc; Poli, Emanuele; Rapson, Chris; Stober, Jörg; Treutterer, Wolfgang

    2012-10-01

    In high performance plasmas, Neoclassical Tearing Modes (NTMs) are regularly observed at reactor-grade beta-values. They limit the achievable normalized beta, which is undesirable because fusion performance scales as beta squared. The method of choice for controlling and avoiding NTMs at AUG is the deposition of ECCD inside the magnetic island for stabilization in real-time (rt). Our approach to tackling such complex control problems using real-time diagnostics allows rigorous optimization of all subsystems. Recent progress in rt-equilibrium reconstruction (< 3.5 ms), rt-localization of NTMs (< 8 ms) and rt beam tracing (< 25 ms) allows closed-loop feedback operation using multiple movable mirrors as the ECCD deposition actuator. The rt-equilibrium uses function parametrization or a fast Grad-Shafranov solver with an option to include rt-MSE measurements. The island localization is based on a correlation of ECE and filtered Mirnov signals. The rt beam-tracing module provides deposition locations and their derivative versus actuator position of multiple gyrotrons. The ``MHD controller'' finally drives the actuators. Results utilizing closed-loop operation with multiple gyrotrons and their effect on NTMs are shown.

  12. Short locking time and low jitter phase-locked loop based on slope charge pump control

    International Nuclear Information System (INIS)

    Guo Zhongjie; Liu Youbao; Wu Longsheng; Wang Xihu; Tang Wei

    2010-01-01

    A novel structure of a phase-locked loop (PLL) characterized by a short locking time and low jitter is presented, which is realized by generating a linear slope charge pump current dependent on monitoring the output of the phase frequency detector (PFD) to implement adaptive bandwidth control. This improved PLL is created by utilizing a fast start-up circuit and a slope current control on a conventional charge pump PLL. First, the fast start-up circuit is enabled to achieve fast pre-charging to the loop filter. Then, when the output pulse of the PFD is larger than a minimum value, the charge pump current is increased linearly by the slope current control to ensure a shorter locking time and a lower jitter. Additionally, temperature variation is attenuated with the temperature compensation in the charge pump current design. The proposed PLL has been fabricated in a kind of DSP chip based on a 0.35 μm CMOS process. Comparing the characteristics with the classical PLL, the proposed PLL shows that it can reduce the locking time by 60% with a low peak-to-peak jitter of 0.3% at a wide operation temperature range. (semiconductor integrated circuits)

  13. Regulatory system for control of nuclear facilities in Bangladesh

    International Nuclear Information System (INIS)

    Mollah, A.S.

    2005-01-01

    All human activities have associated risks. Nuclear programme is no exception. The Bangladesh Atomic Energy Commission (BAEC), constituted in February 1973 through the promulgation of the Presidential order 15 of 1973. Functions of BAEC include research and development in peaceful application of atomic energy, generation of electricity and promotion of international relations congenial to implementation of its programmes and projects. In 1993 the Government of Bangladesh promulgated the law on Nuclear Safety and Radiation Control. Considering the human resources, expertise and facilities needed for implementation of the provisions of the NSRC law, BAEC was entrusted with the responsibility to enforce it. The responsibilities of the BAEC cover nuclear and radiological safety within the installations of BAEC and radiological safety in the manifold applications of radioisotopes and radiation sources within the country. An adequate and competent infrastructure has been built to cater to the diverse nuclear and radiation protection requirements of all nuclear facilities in Bangladesh, arising at different stages from site selection to day-to-day operation. In addition, periodic inspections of the nuclear facilities are carried out. The licensing and regulatory inspection systems for controlling of nuclear installations and radiation sources are established. The paper describes the legal provisions, responsibilities and organization of BAEC with special emphasis on nuclear safety and radiation protection of nuclear facilities in Bangladesh. (author)

  14. Regulatory control of Chinese Proprietary Medicines in Singapore.

    Science.gov (United States)

    Yee, Shen-Kuan; Chu, Swee-Seng; Xu, Yi-Min; Choo, Peck-Lin

    2005-02-01

    In Singapore, there has been a growing public interest in traditional Chinese medicine (TCM), which plays an important role in the healthcare system. With effect from 1 September 1999, the control on Chinese Proprietary Medicines (CPM) was implemented in three phases over a span of 3 years. Under the CPM regulatory framework, CPM importers, wholesalers, manufacturers and re-packers must be licensed and CPM products assessed and listed by the health authority before they are allowed for sale. Product assessment is based on the criteria of safety and quality which include limits of toxic heavy metals and microbial contents. During the 3-year CPM listing exercise, irregularities were detected, including intrinsic toxicity, adulteration, substitution, contamination, misidentification, non-traditional and/or inappropriate usage, incorrect preparation, inappropriate labelling, exaggerated claims and/or advertising. The full implementation of CPM control by September 2001 saw the listing of 7943 CPM products and brought about an improvement in the quality and safety of CPM in Singapore as well as the removal of sub-standard, fake/imitation and adulterated products. The standards of practices by local CPM dealers have also been raised. These improvements have, in turn, increased the level of public confidence in CPM products in Singapore.

  15. Active-Flux-Based, V/f-with-Stabilizing-Loops Versus Sensorless Vector Control of IPMSM Drives

    DEFF Research Database (Denmark)

    Moldovan, Ana; Blaabjerg, Frede; Boldea, Ion

    2011-01-01

    . By this control strategy, a fast dynamic speed response, without steady state error and without speed or current regulators, for all AC machines is obtained. The second control method is a sensorless vector control strategy which also has been implemented and tested, just for comparison.......This paper proposes two control methods for Interior Permanent Magnet Synchronous Motor (IPMSM) Drives. The first one is a V/f control with two stabilizing loops: one loop based on active flux balance for voltage magnitude correction and a second, based on speed error, with voltage phase correction...

  16. Hardware-in-the-loop-based development methods for mechatronic light control; Hardware-in-the-loop basierte Entwicklungsmethodik fuer eine mechatronische Leuchtweiteregelung

    Energy Technology Data Exchange (ETDEWEB)

    Opgen-Rhein, P.

    2005-07-01

    A hardware-in-the-loop solution is presented which in the system integration phase takes account of the process of functional property validation of mechatronic light control systems. The method is not tested on the road but on a test rig with defined boundary conditions. This test stand, combined with objective assessment criteria developed for the specific requirements, helps to minimize the number of costly road tests still required. Using the example of an adaptive filter of a light control system, the author shows how filter paramaters are applied on the test stand, and how the subjective judgement of the driver is taken into account as well in the evaluations. (orig.)

  17. Closed loop auto control system software for Miniature Neutron Source Reactors (MNSRs)

    International Nuclear Information System (INIS)

    Iqbal, Masood; Qadir, Javed

    2009-01-01

    A closed loop auto control system has been developed and implemented at the Pakistan Research Reactor-2 (PARR-2). For interfacing of the site signals with a computer, a data acquisition card was employed. The system utilizes nine signals and, on their basis, carries out continuous on-line analysis, maintaining safe operation. On-line reactivity measurement is included in this software. Also, it generates control signals for keeping the reactor at the desired power level in auto-mode round-the-clock without human intervention. In case of abnormal conditions for either power or temperature or radiation level, alarms are initiated and if their levels reach beyond prescribed safe operation regime, automatic shutdown sequence is initiated. The control system has been thoroughly tested for various postulated scenarios. The test results have been in good agreement with the expected response. (orig.)

  18. Efficacy determinants of subcutaneous microdose glucagon during closed-loop control.

    Science.gov (United States)

    Russell, Steven J; El-Khatib, Firas H; Nathan, David M; Damiano, Edward R

    2010-11-01

    During a previous clinical trial of a closed-loop blood glucose (BG) control system that administered insulin and microdose glucagon subcutaneously, glucagon was not uniformly effective in preventing hypoglycemia (BGMicrodose glucagon administration was relatively ineffective in preventing hypoglycemia when plasma insulin levels exceeded the controller's online estimate by >60%. After the algorithm PK parameters were globally adjusted, insulin dosing was more conservative and microdose glucagon administration was very effective in reducing hypoglycemia while maintaining normal plasma glucagon levels. Improvements in the accuracy of the controller's online estimate of plasma insulin levels could be achieved if ultrarapid-acting insulin formulations could be developed with faster absorption and less intra- and intersubject variability than the current insulin analogs available today. © 2010 Diabetes Technology Society.

  19. Model-Based Closed-Loop Glucose Control in Type 1 Diabetes: The DiaCon Experience

    DEFF Research Database (Denmark)

    Schmidt, Signe; Boiroux, Dimitri; Duun-Henriksen, Anne Katrine

    2013-01-01

    Background: To improve type 1 diabetes mellitus (T1DM) management, we developed a model predictive control (MPC) algorithm for closed-loop (CL) glucose control based on a linear second-order deterministic-stochastic model. The deterministic part of the model is specified by three patient-specific......Background: To improve type 1 diabetes mellitus (T1DM) management, we developed a model predictive control (MPC) algorithm for closed-loop (CL) glucose control based on a linear second-order deterministic-stochastic model. The deterministic part of the model is specified by three patient...... crossover studies. Study 1 compared CL with open-loop (OL) control. Study 2 compared glucose control after CL initiation in the euglycemic (CL-Eu) and hyperglycemic (CL-Hyper) ranges, respectively. Patients were studied from 22:00–07:00 on two separate nights. Results: Each study included six T1DM patients...

  20. LOW-INCOME, MINORITY FATHERS’ CONTROL STRATEGIES AND THEIR CHILDREN'S REGULATORY SKILLS

    OpenAIRE

    Malin, Jenessa L.; Cabrera, Natasha J.; Karberg, Elizabeth; Aldoney, Daniela; Rowe, Meredith Lee

    2014-01-01

    The current study explored the bidirectional association of children's individual characteristics, fathers' control strategies at 24-months and children's regulatory skills at pre-kindergarten (pre-K). Using a sample of low-income minority families with 2-year-olds from the Early Head Start Evaluation Research Program (n = 71) we assessed the association between child gender and vocabulary skills, fathers' control strategies at 24-months (e.g., regulatory behavior and regulatory language), an...

  1. A wirelessly-powered homecage with animal behavior analysis and closed-loop power control.

    Science.gov (United States)

    Yaoyao Jia; Zheyuan Wang; Canales, Daniel; Tinkler, Morgan; Chia-Chun Hsu; Madsen, Teresa E; Mirbozorgi, S Abdollah; Rainnie, Donald; Ghovanloo, Maysam

    2016-08-01

    This paper presents a new EnerCage-homecage system, EnerCage-HC2, for longitudinal electrophysiology data acquisition experiments on small freely moving animal subjects, such as rodents. EnerCage-HC2 is equipped with multi-coil wireless power transmission (WPT), closed-loop power control, bidirectional data communication via Bluetooth Low Energy (BLE), and Microsoft Kinect® based animal behavior tracking and analysis. The EnerCage-HC2 achieves a homogeneous power transfer efficiency (PTE) of 14% on average, with ~42 mW power delivered to the load (PDL) at a nominal height of 7 cm by the closed-loop power control mechanism. The Microsoft Kinect® behavioral analysis algorithm can not only track the animal position in real-time but also classify 5 different types of rodent behaviors: standstill, walking, grooming, rearing, and rotating. A proof-of-concept in vivo experiment was conducted on two awake freely behaving rats while successfully operating a one-channel stimulator and generating an ethogram.

  2. Adaptable Single Active Loop Thermal Control System (TCS) for Future Space Missions

    Science.gov (United States)

    Mudawar, Issam; Lee, Seunghyun; Hasan, Mohammad

    2015-01-01

    This presentation will examine the development of a thermal control system (TCS) for future space missions utilizing a single active cooling loop. The system architecture enables the TCS to be reconfigured during the various mission phases to respond, not only to varying heat load, but to heat rejection temperature as well. The system will consist of an accumulator, pump, cold plates (evaporators), condenser radiator, and compressor, in addition to control, bypass and throttling valves. For cold environments, the heat will be rejected by radiation, during which the compressor will be bypassed, reducing the system to a simple pumped loop that, depending on heat load, can operate in either a single-phase liquid mode or two-phase mode. For warmer environments, the pump will be bypassed, enabling the TCS to operate as a heat pump. This presentation will focus on recent findings concerning two-phase flow regimes, pressure drop, and heat transfer coefficient trends in the cabin and avionics micro-channel heat exchangers when using the heat pump mode. Also discussed will be practical implications of using micro-channel evaporators for the heat pump.

  3. Closed Loop Sawtooth Period Control Using Variable Eccd Injection Angles on Tore Supra

    International Nuclear Information System (INIS)

    Lennholm, M.; Eriksson, L.G.; Turco, F.; Bouquey, F.; Darbos, C.; Dumont, R.; Giruzzi, G.; Jung, M.; Lambert, R.; Magne, R.; Molina, D.; Moreau, P.; Rimini, F.; Segui, J.L.; Song, S.; Traisnel, E.

    2009-01-01

    Closed loop control of the period of fast ion stabilized sawtooth has been demonstrated for the first time on Tore Supra by varying the electron cyclotron current drive (ECCD) injection angles in real time. Fast ions generated by up to 4 MW of central ion cyclotron resonance heating (ICRH) increased the sawtooth period from the ohmic value of 25 ms to 60 to 100 ms. This sawtooth period was reduced to 30 ms by the addition of only 300 kW of ECCD. In ICRH heated shots where the normalized minor radius of the ECCD absorption location was swept from 0.4 to 0.05 in 4 s, the sawtooth period showed an abrupt change from 70 to 30 ms when the ECCD deposition normalized minor radius reached ∼ 0.2. This short period was then maintained until the absorption location moved well inside the sawtooth inversion radius at which point it abruptly returned to 70 ins. A closed loop controller was implemented that allowed the sawtooth period to be switched in real time between short and long sawteeth with a response time of the order of 1 s. (authors)

  4. A two-component regulatory system controls autoregulated serpin expression in Bifidobacterium breve UCC2003.

    Science.gov (United States)

    Alvarez-Martin, Pablo; O'Connell Motherway, Mary; Turroni, Francesca; Foroni, Elena; Ventura, Marco; van Sinderen, Douwe

    2012-10-01

    This work reports on the identification and molecular characterization of a two-component regulatory system (2CRS), encoded by serRK, which is believed to control the expression of the ser(2003) locus in Bifidobacterium breve UCC2003. The ser(2003) locus consists of two genes, Bbr_1319 (sagA) and Bbr_1320 (serU), which are predicted to encode a hypothetical membrane-associated protein and a serpin-like protein, respectively. The response regulator SerR was shown to bind to the promoter region of ser(2003), and the probable recognition sequence of SerR was determined by a combinatorial approach of in vitro site-directed mutagenesis coupled to transcriptional fusion and electrophoretic mobility shift assays (EMSAs). The importance of the serRK 2CRS in the response of B. breve to protease-mediated induction was confirmed by generating a B. breve serR insertion mutant, which was shown to exhibit altered ser(2003) transcriptional induction patterns compared to the parent strain, UCC2003. Interestingly, the analysis of a B. breve serU mutant revealed that the SerRK signaling pathway appears to include a SerU-dependent autoregulatory loop.

  5. High Performance Motion-Planner Architecture for Hardware-In-the-Loop System Based on Position-Based-Admittance-Control

    OpenAIRE

    Francesco La Mura; Giovanni Todeschini; Hermes Giberti

    2018-01-01

    This article focuses on a Hardware-In-the-Loop application developed from the advanced energy field project LIFES50+. The aim is to replicate, inside a wind gallery test facility, the combined effect of aerodynamic and hydrodynamic loads on a floating wind turbine model for offshore energy production, using a force controlled robotic device, emulating floating substructure’s behaviour. In addition to well known real-time Hardware-In-the-Loop (HIL) issues, the particular application presented ...

  6. One Layer Nonlinear Economic Closed-Loop Generalized Predictive Control for a Wastewater Treatment Plant

    Directory of Open Access Journals (Sweden)

    Hicham El bahja

    2018-04-01

    Full Text Available The main scope of this paper is the proposal of a new single layer Nonlinear Economic Closed-Loop Generalized Predictive Control (NECLGPC as an efficient advanced control technique for improving economics in the operation of nonlinear plants. Instead of the classic dual-mode MPC (model predictive controller schemes, where the terminal control law defined in the terminal region is obtained offline solving a linear quadratic regulator problem, here the terminal control law in the NECLGPC is determined online by an unconstrained Nonlinear Generalized Predictive Control (NGPC. In order to make the optimization problem more tractable two considerations have been made in the present work. Firstly, the prediction model consisting of a nonlinear phenomenological model of the plant is expressed with linear structure and state dependent matrices. Secondly, instead of including the nonlinear economic cost in the objective function, an approximation of the reduced gradient of the economic function is used. These assumptions allow us to design an economic unconstrained nonlinear GPC analytically and to state the NECLGPC allow for the design of an economic problem as a QP (Quadratic Programing problem each sampling time. Four controllers based on GPC that differ in designs and structures are compared with the proposed control technique in terms of process performance and energy costs. Particularly, the methodology is implemented in the N-Removal process of a Wastewater Treatment Plant (WWTP and the results prove the efficiency of the method and that it can be used profitably in practical cases.

  7. Breaking a habit: a further role of the phonological loop in action control.

    Science.gov (United States)

    Saeki, Erina; Baddeley, Alan D; Hitch, Graham J; Saito, Satoru

    2013-10-01

    Recent research has suggested that keeping track of a task goal in rapid task switching may depend on the phonological loop component of working memory. In this study, we investigated whether the phonological loop plays a similar role when a single switch extending over several trials is required after many trials on which one has performed a competing task. Participants were shown pairs of digits varying in numerical and physical size, and they were required to decide which digit was numerically or physically larger. An experimental cycle consisted of four blocks of 24 trials. In Experiment 1, participants in the task change groups performed the numerical-size judgment task during the first three blocks, and then changed to the physical-size judgment task in the fourth. Participants in the continuation groups performed only the physical-size judgment task throughout all four blocks. We found negative effects of articulatory suppression on the fourth block, but only in the task change groups. Experiment 2 was a replication, with the modification that both groups received identical instructions and practice. Experiment 3 was a further replication using numerical-size judgment as the target task. The results showed a pattern similar to that from Experiment 1, with negative effects of articulatory suppression found only in the task change group. The congruity of numerical and physical size had a reliable effect on performance in all three experiments, but unlike the task change, it did not reliably interact with articulatory suppression. The results suggest that in addition to its well-established role in rapid task switching, the phonological loop also contributes to active goal maintenance in longer-term action control.

  8. Regulatory control in the rehabilitation of contaminated sites in Syria

    International Nuclear Information System (INIS)

    Shweikani, R.; Suman, H.

    2002-01-01

    The work described in this paper is concerning the regulatory control set by the Atomic Energy Commission of Syria (AECS) for the contaminated sites with Naturally Occurring Radioactive Materials (NORM) in the oil industries in the northeast of Syria. These sites lie in a desert region with poor population density and low occupancy. The decision was made to use the activity concentration of 226 Ra per unit mass as a measure to identify the need for cleanup. Two limits were set for this purpose so that contamination concentration above the higher limit is defined as waste that has to be excavated from the site, while contamination concentration between the two limits can be dealt with on site. Contamination concentration below the lower limit was looked at as acceptable. Remediation plan to transfer the contaminated soil, with radium concentration over the higher limit, to an engineered disposal pit was adopted. Proper stabilisation measures and environmental monitoring programme were requested by the AECS and considered as essential parts of the remediation plan. (author)

  9. Irradiation-induced angiogenesis is associated with an MMP-9-miR-494-syndecan-1 regulatory loop in medulloblastoma cells.

    Science.gov (United States)

    Asuthkar, S; Velpula, K K; Nalla, A K; Gogineni, V R; Gondi, C S; Rao, J S

    2014-04-10

    Matrix metalloproteinase-9 (MMP-9) represents one of the most prominent proteins associated with tumorigenesis and is a modulator of the tumor microenvironment during angiogenesis. Recently, syndecan-1 (SDC1), a transmembrane heparan sulfate-bearing proteoglycan, was also speculated to have a critical role in contributing to angiogenesis when associated with MMP-9. However, the mechanism behind their synergistic regulation is not fully understood. In the current study, we report for the first time that ionizing radiation (IR)-induced MMP-9 enhances SDC1 shedding, corroborating to tube-inducing ability of medulloblastoma (MB) cells. Furthermore, we observed that the tumor angiogenesis is associated with higher MMP-9-SDC1 interactions on both the cell surface and extracellular medium. Our results also revealed the existence of a novel regulatory mechanism where MMP-9 drives the suppression of miR-494, resulting in enhanced SDC1 shedding and angiogenesis. From the in situ hybridization analysis, we found that MMP-9-specific shRNA (shMMP-9) treatment of mouse intracranial tumors resulted in elevated expression of miR-494. This negative correlation between MMP-9 and miR-494 levels was observed to be dependent on the methylation status of a miR-494 promoter-associated CpG island region (-186 to -20), which was confirmed by bisulfite-sequencing and methylation-specific PCR (MSP) analysis. Further, validation of MMP-9 and SDC1 3'-untranslated region (3'-UTR) targets with luciferase reporter assay provided a more favorable result for miR-494-mediated regulation of SDC1 but not of MMP-9, suggesting that the 3'-UTR of SDC1 mRNA is a direct target of miR-494. Overall, our results indicate that angiogenesis induced by radiotherapy is associated with an MMP-9-miR-494-SDC1 regulatory loop and that MMP-9-SDC1 activity creates a negative feedback loop by regulating the expression of miR-494.

  10. Stabilization and analytical tuning rule of double-loop control scheme for unstable dead-time process

    Science.gov (United States)

    Ugon, B.; Nandong, J.; Zang, Z.

    2017-06-01

    The presence of unstable dead-time systems in process plants often leads to a daunting challenge in the design of standard PID controllers, which are not only intended to provide close-loop stability but also to give good performance-robustness overall. In this paper, we conduct stability analysis on a double-loop control scheme based on the Routh-Hurwitz stability criteria. We propose to use this unstable double-loop control scheme which employs two P/PID controllers to control first-order or second-order unstable dead-time processes typically found in process industries. Based on the Routh-Hurwitz stability necessary and sufficient criteria, we establish several stability regions which enclose within them the P/PID parameter values that guarantee close-loop stability of the double-loop control scheme. A systematic tuning rule is developed for the purpose of obtaining the optimal P/PID parameter values within the established regions. The effectiveness of the proposed tuning rule is demonstrated using several numerical examples and the result are compared with some well-established tuning methods reported in the literature.

  11. Adolescent threat-related interpretive bias and its modification: the moderating role of regulatory control

    NARCIS (Netherlands)

    Salemink, E.; Wiers, R.W.

    2012-01-01

    Dual process models describe psychopathology as the consequence of an imbalance between a fast, impulsive system and a regulatory control system and have recently been applied to anxiety disorders. The aim of the current study was to specifically examine the role of a regulatory control system in

  12. Authority Defied : Need for Cognitive Closure Influences Regulatory Control When Resisting Authority

    NARCIS (Netherlands)

    Damen, Tom G. E.; van Leeuwen, Matthijs L.; Dijksterhuis, Ap; van Baaren, Rick B.

    The present studies examined whether differences in need for cognitive closure (NCC) were related to differences in regulatory control when confronted with authority. In two studies, levels of regulatory control were measured when participants resisted (Study 1; N = 46) or prepared to resist the

  13. Authority Defied: Need for Cognitive Closure Influences Regulatory Control When Resisting Authority

    NARCIS (Netherlands)

    Damen, T.G.E.; Leeuwen, M.L. van; Dijksterhuis, A.J.; Baaren, R.B. van

    2014-01-01

    The present studies examined whether differences in need for cognitive closure (NCC) were related to differences in regulatory control when confronted with authority. In two studies, levels of regulatory control were measured when participants resisted (Study 1; N = 46) or prepared to resist the

  14. An approach of optimal sensitivity applied in the tertiary loop of the automatic generation control

    Energy Technology Data Exchange (ETDEWEB)

    Belati, Edmarcio A. [CIMATEC - SENAI, Salvador, BA (Brazil); Alves, Dilson A. [Electrical Engineering Department, FEIS, UNESP - Sao Paulo State University (Brazil); da Costa, Geraldo R.M. [Electrical Engineering Department, EESC, USP - Sao Paulo University (Brazil)

    2008-09-15

    This paper proposes an approach of optimal sensitivity applied in the tertiary loop of the automatic generation control. The approach is based on the theorem of non-linear perturbation. From an optimal operation point obtained by an optimal power flow a new optimal operation point is directly determined after a perturbation, i.e., without the necessity of an iterative process. This new optimal operation point satisfies the constraints of the problem for small perturbation in the loads. The participation factors and the voltage set point of the automatic voltage regulators (AVR) of the generators are determined by the technique of optimal sensitivity, considering the effects of the active power losses minimization and the network constraints. The participation factors and voltage set point of the generators are supplied directly to a computational program of dynamic simulation of the automatic generation control, named by power sensitivity mode. Test results are presented to show the good performance of this approach. (author)

  15. Closed-Loop Control Without Meal Announcement in Type 1 Diabetes.

    Science.gov (United States)

    Cameron, Faye M; Ly, Trang T; Buckingham, Bruce A; Maahs, David M; Forlenza, Gregory P; Levy, Carol J; Lam, David; Clinton, Paula; Messer, Laurel H; Westfall, Emily; Levister, Camilla; Xie, Yan Yan; Baysal, Nihat; Howsmon, Daniel; Patek, Stephen D; Bequette, B Wayne

    2017-09-01

    A fully closed-loop insulin-only system was developed to provide glucose control in patients with type 1 diabetes without requiring announcement of meals or activity. Our goal was to assess initial safety and efficacy of this system. The multiple model probabilistic controller (MMPPC) anticipates meals when the patient is awake. The controller used the subject's basal rates and total daily insulin dose for initialization. The system was tested at two sites on 10 patients in a 30-h inpatient study, followed by 15 subjects at three sites in a 54-h supervised hotel study, where the controller was challenged by exercise and unannounced meals. The system was implemented on the UVA DiAs system using a Roche Spirit Combo Insulin Pump and a Dexcom G4 Continuous Glucose Monitor. The mean overall (24-h basis) and nighttime (11 PM-7 AM) continuous glucose monitoring (CGM) values were 142 and 125 mg/dL during the inpatient study. The hotel study used a different daytime tuning and manual announcement, instead of automatic detection, of sleep and wake periods. This resulted in mean overall (24-h basis) and nighttime CGM values of 152 and 139 mg/dL for the hotel study and there was also a reduction in hypoglycemia events from 1.6 to 0.91 events/patient/day. The MMPPC system achieved a mean glucose that would be particularly helpful for people with an elevated A1c as a result of frequent missed meal boluses. Current full closed loop has a higher risk for hypoglycemia when compared with algorithms using meal announcement.

  16. Formulating adaptive radiation therapy (ART) treatment planning into a closed-loop control framework

    International Nuclear Information System (INIS)

    Zerda, Adam de la; Armbruster, Benjamin; Xing Lei

    2007-01-01

    While ART has been studied for years, the specific quantitative implementation details have not. In order for this new scheme of radiation therapy (RT) to reach its potential, an effective ART treatment planning strategy capable of taking into account the dose delivery history and the patient's on-treatment geometric model must be in place. This paper performs a theoretical study of dynamic closed-loop control algorithms for ART and compares their utility with data from phantom and clinical cases. We developed two classes of algorithms: those Adapting to Changing Geometry and those Adapting to Geometry and Delivered Dose. The former class takes into account organ deformations found just before treatment. The latter class optimizes the dose distribution accumulated over the entire course of treatment by adapting at each fraction, not only to the information just before treatment about organ deformations but also to the dose delivery history. We showcase two algorithms in the class of those Adapting to Geometry and Delivered Dose. A comparison of the approaches indicates that certain closed-loop ART algorithms may significantly improve the current practice. We anticipate that improvements in imaging, dose verification and reporting will further increase the importance of adaptive algorithms

  17. Akt kinase C-terminal modifications control activation loop dephosphorylation and enhance insulin response.

    Science.gov (United States)

    Chan, Tung O; Zhang, Jin; Tiegs, Brian C; Blumhof, Brian; Yan, Linda; Keny, Nikhil; Penny, Morgan; Li, Xue; Pascal, John M; Armen, Roger S; Rodeck, Ulrich; Penn, Raymond B

    2015-10-01

    The Akt protein kinase, also known as protein kinase B, plays key roles in insulin receptor signalling and regulates cell growth, survival and metabolism. Recently, we described a mechanism to enhance Akt phosphorylation that restricts access of cellular phosphatases to the Akt activation loop (Thr(308) in Akt1 or protein kinase B isoform alpha) in an ATP-dependent manner. In the present paper, we describe a distinct mechanism to control Thr(308) dephosphorylation and thus Akt deactivation that depends on intramolecular interactions of Akt C-terminal sequences with its kinase domain. Modifications of amino acids surrounding the Akt1 C-terminal mTORC2 (mammalian target of rapamycin complex 2) phosphorylation site (Ser(473)) increased phosphatase resistance of the phosphorylated activation loop (pThr(308)) and amplified Akt phosphorylation. Furthermore, the phosphatase-resistant Akt was refractory to ceramide-dependent dephosphorylation and amplified insulin-dependent Thr(308) phosphorylation in a regulated fashion. Collectively, these results suggest that the Akt C-terminal hydrophobic groove is a target for the development of agents that enhance Akt phosphorylation by insulin. © 2015 Authors; published by Portland Press Limited.

  18. Regulatory control of radiation sources and radioactive materials in the Czech Republic

    International Nuclear Information System (INIS)

    Drabova, D.; Prouza, Z.

    2001-01-01

    The paper describes legal and regulatory provisions for radiation protection and safe use of sources of ionizing radiation in the Czech Republic with special emphasis on aspects of bringing activities under regulatory control and releasing them from it. It covers the development of a new legal framework, the work of the regulatory body, an overview of sources in use and provisions to achieve effective regulatory control of facilities and releases of radioactive material into the environment. Also, it describes reported unusual events with a proposed scheme for their classification and evaluation. (author)

  19. Open-loop position tracking control of a piezoceramic flexible beam using a dynamic hysteresis compensator

    International Nuclear Information System (INIS)

    Nguyen, Phuong-Bac; Choi, Seung-Bok

    2010-01-01

    This paper proposes a novel hysteresis compensator to enhance control accuracy in open-loop position tracking control of a piezoceramic flexible beam. The proposed hysteresis compensator consists of two components: a rate-independent hysteresis compensator and a nonlinear filter. The compensator is formulated based on the inverse Preisach model, while the weight coefficients of the filter are identified adaptively using a recursive least square (RLS) algorithm. In this work, two dynamic hysteresis compensators (or rate-independent hysteresis compensators) are developed by adopting two different nonlinear filters: Volterra and bilinear filters. In order to demonstrate the improved control accuracy of the proposed dynamic compensators, a flexible beam associated with the piezoceramic actuator is modeled using the finite element method (FEM) and Euler–Bernoulli beam theory. The beam model is then integrated with the proposed hysteresis model to achieve accurate position tracking control at the tip of the beam. An experimental investigation on the tip position tracking control is undertaken by realizing three different hysteresis compensators: a rate-independent hysteresis compensator, a rate-dependent hysteresis compensator with a Volterra nonlinear filter and a rate-independent hysteresis compensator with a bilinear nonlinear filter. It is shown that the proposed dynamic hysteresis compensators can provide much better tracking control accuracy than conventional rate-independent hysteresis compensators

  20. Experimental evaluation of open-loop UpLink Power Control using ACTS

    Science.gov (United States)

    Dissanayake, Asoka

    1995-01-01

    The present investigation deals with the implementation of open-loop up-link power control using a beacon signal in the down-link frequency band as the control parameter. A power control system was developed and tested using the ACTS satellite. ACTS carries beacon signals in both up- and down-link bands with which the relationship between the up- and down-link fading can be established. A power controlled carrier was transmitted to the ACTS satellite from a NASA operated ground station and the transponded signal was received at COMSAT Laboratories using a terminal that was routinely used to monitor the two ACTS beacon signals. The experiment ran for a period of approximately six months and the collected data were used to evaluate the performance of the power control system. A brief review of propagation factors involved in estimating the up-link fade using a beacon signal in the down-link band are presented. The power controller design and the experiment configuration are discussed. Results of the experiment are discussed.

  1. A neurochemical closed-loop controller for deep brain stimulation: toward individualized smart neuromodulation therapies.

    Directory of Open Access Journals (Sweden)

    Peter Jonas Grahn

    2014-06-01

    Full Text Available Current strategies for optimizing deep brain stimulation (DBS therapy involve multiple postoperative visits. During each visit, stimulation parameters are adjusted until desired therapeutic effects are achieved and adverse effects are minimized. However, the efficacy of these therapeutic parameters may decline with time due at least in part to disease progression, interactions between the host environment and the electrode, and lead migration. As such, development of closed-loop control systems that can respond to changing neurochemical environments, tailoring DBS therapy to individual patients, is paramount for improving the therapeutic efficacy of DBS.Evidence obtained using electrophysiology and imaging techniques in both animals and humans suggests that DBS works by modulating neural network activity. Recently, animal studies have shown that stimulation-evoked changes in neurotransmitter release that mirror normal physiology are associated with the therapeutic benefits of DBS. Therefore, to fully understand the neurophysiology of DBS and optimize its efficacy, it may be necessary to look beyond conventional electrophysiological analyses and characterize the neurochemical effects of therapeutic and non-therapeutic stimulation. By combining electrochemical monitoring and mathematical modeling techniques, we can potentially replace the trial-and-error process used in clinical programming with deterministic approaches that help attain optimal and stable neurochemical profiles. In this manuscript, we summarize the current understanding of electrophysiological and electrochemical processing for control of neuromodulation therapies. Additionally, we describe a proof-of-principle closed-loop controller that characterizes DBS-evoked dopamine changes to adjust stimulation parameters in a rodent model of DBS. The work described herein represents the initial steps toward achieving a smart neuroprosthetic system for treatment of neurologic and

  2. Loop kinematics

    International Nuclear Information System (INIS)

    Migdal, A.A.

    1982-01-01

    Basic operators acting in the loop space are introduced. The topology of this space and properties of the Stokes type loop functionals are discussed. The parametrically invariant loop calculus developed here is used in the loop dynamics

  3. Multisession, noninvasive closed-loop neuroprosthetic control of grasping by upper limb amputees.

    Science.gov (United States)

    Agashe, H A; Paek, A Y; Contreras-Vidal, J L

    2016-01-01

    Upper limb amputation results in a severe reduction in the quality of life of affected individuals due to their inability to easily perform activities of daily living. Brain-machine interfaces (BMIs) that translate grasping intent from the brain's neural activity into prosthetic control may increase the level of natural control currently available in myoelectric prostheses. Current BMI techniques demonstrate accurate arm position and single degree-of-freedom grasp control but are invasive and require daily recalibration. In this study we tested if transradial amputees (A1 and A2) could control grasp preshaping in a prosthetic device using a noninvasive electroencephalography (EEG)-based closed-loop BMI system. Participants attempted to grasp presented objects by controlling two grasping synergies, in 12 sessions performed over 5 weeks. Prior to closed-loop control, the first six sessions included a decoder calibration phase using action observation by the participants; thereafter, the decoder was fixed to examine neuroprosthetic performance in the absence of decoder recalibration. Ability of participants to control the prosthetic was measured by the success rate of grasping; ie, the percentage of trials within a session in which presented objects were successfully grasped. Participant A1 maintained a steady success rate (63±3%) across sessions (significantly above chance [41±5%] for 11 sessions). Participant A2, who was under the influence of pharmacological treatment for depression, hormone imbalance, pain management (for phantom pain as well as shoulder joint inflammation), and drug dependence, achieved a success rate of 32±2% across sessions (significantly above chance [27±5%] in only two sessions). EEG signal quality was stable across sessions, but the decoders created during the first six sessions showed variation, indicating EEG features relevant to decoding at a smaller timescale (100ms) may not be stable. Overall, our results show that (a) an EEG

  4. Interaction between beam control and rf feedback loops for high Q cavities an heavy beam loading. Revision A

    International Nuclear Information System (INIS)

    Mestha, L.K.; Kwan, C.M.; Yeung, K.S.

    1994-04-01

    An open-loop state space model of all the major low-level rf feedback control loops is derived. The model has control and state variables for fast-cycling machines to apply modern multivariable feedback techniques. A condition is derived to know when exactly we can cross the boundaries between time-varying and time-invariant approaches for a fast-cycling machine like the Low Energy Booster (LEB). The conditions are dependent on the Q of the cavity and the rate at which the frequency changes with time. Apart from capturing the time-variant characteristics, the errors in the magnetic field are accounted in the model to study the effects on synchronization with the Medium Energy Booster (MEB). The control model is useful to study the effects on beam control due to heavy beam loading at high intensities, voltage transients just after injection especially due to time-varying voltages, instability thresholds created by the cavity tuning feedback system, cross coupling between feedback loops with and without direct rf feedback etc. As a special case we have shown that the model agrees with the well known Pedersen model derived for the CERN PS booster. As an application of the model we undertook a detailed study of the cross coupling between the loops by considering all of them at once for varying time, Q and beam intensities. A discussion of the method to identify the coupling is shown. At the end a summary of the identified loop interactions is presented

  5. The IAEA Regional Training Course on Regulatory Control of Radiation Sources

    International Nuclear Information System (INIS)

    2000-01-01

    Materials of the IAEA Regional Training Course contains 8 presented lectures. Authors deals with regulatory control of radiation sources. The next materials of the IAEA were presented: Organization and implementation of a national regulatory infrastructure governing protection against ionizing radiation and the safety of radiation sources. (IAEA-TECDOC-1067); Safety assessment plants for authorization and inspection of radiation sources (IAEA-TECDOC-1113); Regulatory authority information system RAIS, Version 2.0, Instruction manual

  6. Numerical simulations and analyses of temperature control loop heat pipe for space CCD camera

    Science.gov (United States)

    Meng, Qingliang; Yang, Tao; Li, Chunlin

    2016-10-01

    As one of the key units of space CCD camera, the temperature range and stability of CCD components affect the image's indexes. Reasonable thermal design and robust thermal control devices are needed. One kind of temperature control loop heat pipe (TCLHP) is designed, which highly meets the thermal control requirements of CCD components. In order to study the dynamic behaviors of heat and mass transfer of TCLHP, particularly in the orbital flight case, a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling. The temperature control principle and details of mathematical model are presented. The model is used to study operating state, flow and heat characteristics based upon the analyses of variations of temperature, pressure and quality under different operating modes and external heat flux variations. The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well, and always ensure good temperature stability and uniformity. By comparison between flight data and simulated results, it is found that the model is to be accurate to within 1°C. The model can be better used for predicting and understanding the transient performance of TCLHP.

  7. DDS-based control loops for the RF system at INFN-LNS

    International Nuclear Information System (INIS)

    Caruso, A.; Calabretta, L.; Cosentino, G.; Sparta, A.; Speziale, F.

    2005-01-01

    In the last two years a new radio-frequency source generator has been working to synthesize the driving sinusoidal signals of the RF systems at LNS. This device is based on Direct Digital Synthesis (DDS) technique. Every time you need a constant relation of phase between several RF signals, our DDS-based multiple frequencies generator produces these high frequency waveforms. The good results of this DDS synthesizer technique, make us feel confident that we can develop a new DDS control system for the various RF equipment. The AD9852/54 a commercial DDS microchip, will be the core of this new control system. The component allows, through digital ports, the manipulation of the frequency, amplitude and phase of the developed RF-carrier without any interruption to the latter. In this way we would have a complete DDS control system capable of stabilizing amplitude, phase and tuning ensuring the present stability of the analog control loops. The remaining operations, such as turning on/off and protection of the system will be performed at the same time. The prototype of this new DDS control, its technical performances and the experimental results will be presented in this paper. (author)

  8. Total aircraft flight-control system - Balanced open- and closed-loop control with dynamic trim maps

    Science.gov (United States)

    Smith, G. A.; Meyer, G.

    1979-01-01

    The availability of the airborne digital computer has made possible a Total Aircraft Flight Control System (TAFCOS) that uses virtually the complete nonlinear propulsive and aerodynamic data for the aircraft to construct dynamic trim maps that represent an inversion of the aircraft model. The trim maps, in series with the aircraft, provide essentially a linear feed-forward path. Basically, open-loop trajectory control is employed with only a small perturbation feedback signal required to compensate for inaccuracy in the aircraft model and for external disturbances. Simulation results for application to an automatic carrier-landing system are presented. Flight-test results for a STOL aircraft operating automatically over a major portion of its flight regime are presented. The concept promises a more rapid and straightforward design from aerodynamic principles, particularly for highly nonlinear configurations, and requires substantially less digital computer capacity than conventional automatic flight-control system designs.

  9. MODELING OF THE HEAT PUMP STATION CONTROLABLE LOOP OF AN INTERMEDIATE HEAT-TRANSFER AGENT (Part II

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2011-08-01

    Full Text Available It is studied the model of the heat pump station controllable loop of an intermediate heat-transfer agent for the use in wineries. There are demonstrated transients after the disturbing action of the temperature on the input of cooling jacket of the fermentation stirred tank. There are compared different control laws of the object.

  10. Design of permanent magnet synchronous motor speed loop controller based on sliding mode control algorithm

    Science.gov (United States)

    Qiang, Jiang; Meng-wei, Liao; Ming-jie, Luo

    2018-03-01

    Abstract.The control performance of Permanent Magnet Synchronous Motor will be affected by the fluctuation or changes of mechanical parameters when PMSM is applied as driving motor in actual electric vehicle,and external disturbance would influence control robustness.To improve control dynamic quality and robustness of PMSM speed control system, a new second order integral sliding mode control algorithm is introduced into PMSM vector control.The simulation results show that, compared with the traditional PID control,the modified control scheme optimized has better control precision and dynamic response ability and perform better with a stronger robustness facing external disturbance,it can effectively solve the traditional sliding mode variable structure control chattering problems as well.

  11. Closed loop control of the induction heating process using miniature magnetic sensors

    Science.gov (United States)

    Bentley, Anthony E.; Kelley, John Bruce; Zutavern, Fred J.

    2003-05-20

    A method and system for providing real-time, closed-loop control of the induction hardening process. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, B.sub.sat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).

  12. Cryogenic thermometer calibration system using a helium cooling loop and a temperature controller [for LHC magnets

    CERN Document Server

    Chanzy, E; Thermeau, J P; Bühler, S; Joly, C; Casas-Cubillos, J; Balle, C

    1998-01-01

    The IPN-Orsay and CERN are designing in close collaboration a fully automated cryogenic thermometer calibration facility which will calibrate in 3 years 10,000 cryogenic thermometers required for the Large Hadron Collider (LHC) operation. A reduced-scale model of the calibration facility has been developed, which enables the calibration of ten thermometers by comparison with two rhodium-iron standard thermometers in the 1.8 K to 300 K temperature range under vacuum conditions. The particular design, based on a helium cooling loop and an electrical temperature controller, gives good dynamic performances. This paper describes the experimental set-up and the data acquisition system. Results of experimental runs are also presented along with the estimated global accuracy for the calibration. (3 refs).

  13. Multi-Evaporator Miniature Loop Heat Pipe for Small Spacecraft Thermal Control. Part 1; New Technologies and Validation Approach

    Science.gov (United States)

    Ku, Jentung; Ottenstein, Laura; Douglas, Donya; Hoang, Triem

    2010-01-01

    Under NASA s New Millennium Program Space Technology 8 (ST 8) Project, four experiments Thermal Loop, Dependable Microprocessor, SAILMAST, and UltraFlex - were conducted to advance the maturity of individual technologies from proof of concept to prototype demonstration in a relevant environment , i.e. from a technology readiness level (TRL) of 3 to a level of 6. This paper presents the new technologies and validation approach of the Thermal Loop experiment. The Thermal Loop is an advanced thermal control system consisting of a miniature loop heat pipe (MLHP) with multiple evaporators and multiple condensers designed for future small system applications requiring low mass, low power, and compactness. The MLHP retains all features of state-of-the-art loop heat pipes (LHPs) and offers additional advantages to enhance the functionality, performance, versatility, and reliability of the system. Details of the thermal loop concept, technical advances, benefits, objectives, level 1 requirements, and performance characteristics are described. Also included in the paper are descriptions of the test articles and mathematical modeling used for the technology validation. An MLHP breadboard was built and tested in the laboratory and thermal vacuum environments for TRL 4 and TRL 5 validations, and an MLHP proto-flight unit was built and tested in a thermal vacuum chamber for the TRL 6 validation. In addition, an analytical model was developed to simulate the steady state and transient behaviors of the MLHP during various validation tests. Capabilities and limitations of the analytical model are also addressed.

  14. Regulatory control and management of radioactive materials in the Philippines

    International Nuclear Information System (INIS)

    Borras, A.M.; Parami, V.K.; Domondon, D.B.

    2001-01-01

    The Philippine Nuclear Research Institute (PNRI) by virtue of Republic Act 2067, as amended, Republic Act 5207 and Executive Order 128 (1987), was mandated to promote, advance and regulate the safe and peaceful applications of nuclear science and technology in the Philippines. The PNRI was formerly the Philippine Atomic Energy Commission, established in 1958. This report aims to share the information and experience of PNRI as a regulatory authority on the administrative, technical and managerial aspects to ensure the safety and security of radioactive material in the country. It describes the country's regulatory framework, operational experiences, international co-operation including reporting system and database, and radiological safety assessment and compliance monitoring. It also briefly discusses the current development of the country's radiological emergency response plan and the radiation protection services offered by the PNRI. In the discussion and recommendations, some of the results of the regulatory information conferences conducted with the end-users are enumerated. (author)

  15. Small RNA-Controlled Gene Regulatory Networks in Pseudomonas putida

    DEFF Research Database (Denmark)

    Bojanovic, Klara

    evolved numerous mechanisms to controlgene expression in response to specific environmental signals. In addition to two-component systems, small regulatory RNAs (sRNAs) have emerged as major regulators of gene expression. The majority of sRNAs bind to mRNA and regulate their expression. They often have...... multiple targets and are incorporated into large regulatory networks and the RNA chaper one Hfq in many cases facilitates interactions between sRNAs and their targets. Some sRNAs also act by binding to protein targets and sequestering their function. In this PhD thesis we investigated the transcriptional....... Detailed insights into the mechanisms through which P. putida responds to different stress conditions and increased understanding of bacterial adaptation in natural and industrial settings were gained. Additionally, we identified genome-wide transcription start sites, andmany regulatory RNA elements...

  16. Two-loop controller for maximizing performance of a grid-connected photovoltaic - fuel cell hybrid power plant

    Science.gov (United States)

    Ro, Kyoungsoo

    The study started with the requirement that a photovoltaic (PV) power source should be integrated with other supplementary power sources whether it operates in a stand-alone or grid-connected mode. First, fuel cells for a backup of varying PV power were compared in detail with batteries and were found to have more operational benefits. Next, maximizing performance of a grid-connected PV-fuel cell hybrid system by use of a two-loop controller was discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC meets the system's requirement for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. The RRPC is able to achieve more versatile control of real/reactive powers than the conventional power sources since the hybrid power plant does not contain any rotating mass. Results of time-domain simulations prove not only effectiveness of the proposed computer models of the two-loop controller, but also their applicability for use in transient stability analysis of the hybrid power plant. Finally, environmental evaluation of the proposed hybrid plant was made in terms of plant's land requirement and lifetime COsb2 emissions, and then compared with that of the conventional fossil-fuel power generating forms.

  17. Closed-loop controlled noninvasive ultrasonic glucose sensing and insulin delivery

    Science.gov (United States)

    Park, Eun-Joo; Werner, Jacob; Jaiswal, Devina; Smith, Nadine Barrie

    2010-03-01

    To prevent complications in diabetes, the proper management of blood glucose levels is essential. Previously, ultrasonic transdermal methods using a light-weight cymbal transducer array has been studied for noninvasive methods of insulin delivery for Type-1 diabetes and glucose level monitoring. In this study, the ultrasound systems of insulin delivery and glucose sensing have been combined by a feedback controller. This study was designed to show the feasibility of the feedback controlled ultrasound system for the noninvasive glucose control. For perspective human application, in vivo experiments were performed on large animals that have a similar size to humans. Four in vivo experiments were performed using about 200 lbs pigs. The cymbal array of 3×3 pattern has been used for insulin delivery at 30 kHz with the spatial-peak temporal-peak intensity (Isptp) of 100 mW/cm2. For glucose sensing, a 2×2 array was operated at 20 kHz with Isptp = 100 mW/cm2. Based on the glucose level determined by biosensors after the ultrasound exposure, the ultrasound system for the insulin delivery was automatically operated. The glucose level of 115 mg/dl was set as a reference value for operating the insulin delivery system. For comparison, the glucose levels of blood samples collected from the ear vein were measured by a commercial glucose meter. Using the ultrasound system operated by the close-loop, feed-back controller, the glucose levels of four pigs were determined every 20 minutes and continuously controlled for 120 minutes. In comparison to the commercial glucose meter, the glucose levels determined by the biosensor were slightly higher. The results of in vivo experiments indicate the feasibility of the feedback controlled ultrasound system using the cymbal array for noninvasive glucose sensing and insulin delivery. Further studies on the extension of the glucose control will be continued for the effective method of glucose control.

  18. Revitalisation of Control and Data Acquisition Systems for Corrosion Test Loop

    International Nuclear Information System (INIS)

    Khairul Handono; Kiswanta; Edy Sumarno

    2008-01-01

    The replacement of control and data acquisition systems for Corrosion Test Loop (CTL) has been conducted. The aim of revitalisation for CTL is to increase controller system performance Kent 4000 which is based on PLC. On the other side revitalisation of acquisition data system is done to build computer based data retrieval system for transformation gauging of parameters in thermalhydraulic experiment of CTL. Previously, data collector system used indicator recorder analog, while data recording is done manually, which caused causing very slow response and the result is less accurate. To increase the user quality of data collector system, the data acquisition system is developed with application program Visual Basic and acquisition apparatus card of data. Result of the activity of revitalisation CTL is to obtain of control systems based on PLC and data acquisition system capable to present information in the form of temperature, pressure and cooling water level interactively, namely easy to read, quickly, realtime and accurate. This results give the improvement of control systems performance and data acquisition system which data storage of acquisition into hard disk in the form of file and further processed in the form of tables or graph to facilitate the analysis. (author)

  19. Stability of Closed Loop Controlled Repetitive Periodic System applied to control of CD-Player

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2005-01-01

    In this paper a criterion for stability of specific control scheme for handling linear dynamic control systems with repetitive periodic sensor faults is derived. The given system and control scheme are described and defined. By combining these with the lifting technique a necessary and sufficient...

  20. Advanced Photovoltaic Inverter Control Development and Validation in a Controller-Hardware-in-the-Loop Test Bed

    Energy Technology Data Exchange (ETDEWEB)

    Prabakar, Kumaraguru [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Shirazi, Mariko [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Singh, Akanksha [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-07

    Penetration levels of solar photovoltaic (PV) generation on the electric grid have increased in recent years. In the past, most PV installations have not included grid-support functionalities. But today, standards such as the upcoming revisions to IEEE 1547 recommend grid support and anti-islanding functions-including volt-var, frequency-watt, volt-watt, frequency/voltage ride-through, and other inverter functions. These functions allow for the standardized interconnection of distributed energy resources into the grid. This paper develops and tests low-level inverter current control and high-level grid support functions. The controller was developed to integrate advanced inverter functions in a systematic approach, thus avoiding conflict among the different control objectives. The algorithms were then programmed on an off-the-shelf, embedded controller with a dual-core computer processing unit and field-programmable gate array (FPGA). This programmed controller was tested using a controller-hardware-in-the-loop (CHIL) test bed setup using an FPGA-based real-time simulator. The CHIL was run at a time step of 500 ns to accommodate the 20-kHz switching frequency of the developed controller. The details of the advanced control function and CHIL test bed provided here will aide future researchers when designing, implementing, and testing advanced functions of PV inverters.

  1. Linear open-loop and closed-loop control theory. Modelling of control paths, robust stability, design of robust controllers, trajectory control with follow-up contorl, polynomial description of MIMO systems, time discrete control loops and scanning control loops; Lineare Regelungs- und Steuerungstheorie. Modellierung von Regelstrecken, Robuste Stabilitaet und Entwurf robuster Regler, Trajektoriensteuerung mit Folgeregelung, Polynomiale Beschreibung von MIMO-Systemen, Zeitdiskrete und Abtastregelkreise

    Energy Technology Data Exchange (ETDEWEB)

    Reinschke, K. [Technische Univ. Dresden (Germany). Inst. fuer Regelungs- und Streuerungstheorie

    2006-07-01

    After the introduction of bachelor and master studies in Germany, new training concepts are required. In the field of engineering, there is a lack of research-oriented German-language textbooks which are also suited for further training of professionally experienced engineers. The author addresses readers with good prior knowledge of mathematics and application-oriented basic training in open-loop and control-loop engineering who intend to deepen their knowledge of the methods of control of linear time-continuous processes. The reader is enabled to apply the mathematical tools of linear system theory for control purposes. Unavoidable uncertainties in the modelling of control paths are considered. The focus is on function theoretical and algebraic aspects which enable the design of robust stabilising controllers as well as trajectory control and follow-up control and also the time-continuous treatment of scanning control loops. There are many examples to illustrate the general laws that are presented. (orig.) [German] Die Einfuehrung von gestuften Bachelor- und Master-Studiengaengen erfordert neue Ausbildungskonzepte. Fuer die Master- und Promotionsstudiengaenge der Ingenieure mangelt es bisher an forschungsorientierten deutschsprachigen Lehrwerken, die zugleich auch zur Fortbildung von berufserfahrenen Ingenieuren geeignet sind. Dieses Buch traegt zur Behebung dieses Mangels bei. Der Autor wendet sich an Leser, die eine gute mathematische Vorbildung und eine anwendungsorientierte Grundausbildung in Regelungs- und Steuerungstechnik abgeschlossen haben und nun tiefer in die Methoden der Regelung und Steuerung von linearen zeitkontinuierlichen Prozessen eindringen wollen. Der Leser wird befaehigt, die mathematischen Werkzeuge der linearen Systemtheorie fuer regelungstechnische Zwecke einzusetzen. Bei der Modellierung von Regelstrecken werden die unvermeidlichen Unbestimmtheiten beruecksichtigt. Im Zentrum stehen die funktionentheoretischen und algebraischen

  2. Combined Discrete Space Voltage Vector with Direct Torque Control for Bearingless Brushless DC Motor and Closed-Loop Suspended Force Control

    Directory of Open Access Journals (Sweden)

    Weiran Wang

    2013-06-01

    Full Text Available In order to improve the performance of bearingless brushless DC motor, a closed-loop suspended force controller combining the discrete space voltage vector modulation is applied and the direct torque control is presented in this paper. Firstly, we increase the number of the control vector to reduce the torque ripple. Then, the suspending equation is constructed which is spired by the direct torque control algorithm. As a result, the closed-loop suspended force controller is built. The simulated and experimental results evaluate the performance of the proposed method. The more advantage is that the proposed algorithm can achieve the fast torque response, reduce the torque ripple, and follow ideal stator flux track. Furthermore, the motor which implants the closed-loop suspended force controller cannot onlyobtain the dynamic response rapidly and displacement control accurately, but also has the characteristics of bearingless brushless DC motor (such as simple structure, high energy efficiency, small volume and low failure rate.

  3. Regulatory philosophy and requirements for radiation control in Canadian uranium mine-mill facilities

    International Nuclear Information System (INIS)

    Dory, A.B.

    1981-10-01

    With the point made that radiation exposure is one of the health hazards of uranium mining and accordingly has to be controlled, the Canadian regulatory philosophy is outlined as it pertains to the uranium mining industry. Two extremes in regulatory approach are examined, and the joint regulatory process is explained. Two examples of poor management performance are given, and the role of mine unions in the regulatory process is touched upon. The development of new regulations to cover ventilation and employee training is sketched briefly. The author concludes with a general expression of objectives for the eighties which include improved personal dosimetry

  4. Closed-loop digital control of nuclear reactors characterized by spatial dynamics

    International Nuclear Information System (INIS)

    Bernard, J.A.; Henry, A.F.; Lanning, D.D.; Meyer, J.E.

    1991-03-01

    This report describes the theoretical development and the evaluation via both simulation and, to a lesser degree, experiment of a digital method for the closed-loop control of power and temperature in reactors characterized by spatial dynamics. The major conclusions of the research are that (1) the sophistication of advanced reactor physics and thermal-hydraulic nodal methods is now such that accurate, real-time models of spatially-dependent, heterogeneous reactor cores can be run on present-generation minicomputers; (2) operation of both present-day commercial reactors as well as the multi-modular reactors now being considered for construction in the United States could be significantly improved by incorporating model-generated information on in-core conditions in a digital controller; and (3) digital controllers for spatially-dependent reactors should have a hierarchical or multi-tiered structure consisting of supervisory algorithms that preclude challenges to the safety system, global control laws designed to provide an optimal response to temperature and power perturbations, and local control laws that maintain parameters such as the margin to departure from nucleate boiling within specification. The technology described is appropriate to present-day pressurized water reactors and to the proposed multi-modular designs. The end-product of this research was a (near) real-time analytic plant-estimation code that was given the acronym POPSICLE for POwer Plant SImulator and ControlLEr. POPSICLE's core neutronics model is based on a quasi-static transient solution of the analytic nodal diffusion equations. 126 refs., 159 figs., 17 tabs

  5. Closed-loop digital control of nuclear reactors characterized by spatial dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J.A. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Nuclear Reactor Lab.); Henry, A.F.; Lanning, D.D.; Meyer, J.E. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Nuclear Engineering)

    1991-03-01

    This report describes the theoretical development and the evaluation via both simulation and, to a lesser degree, experiment of a digital method for the closed-loop control of power and temperature in reactors characterized by spatial dynamics. The major conclusions of the research are that (1) the sophistication of advanced reactor physics and thermal-hydraulic nodal methods is now such that accurate, real-time models of spatially-dependent, heterogeneous reactor cores can be run on present-generation minicomputers; (2) operation of both present-day commercial reactors as well as the multi-modular reactors now being considered for construction in the United States could be significantly improved by incorporating model-generated information on in-core conditions in a digital controller; and (3) digital controllers for spatially-dependent reactors should have a hierarchical or multi-tiered structure consisting of supervisory algorithms that preclude challenges to the safety system, global control laws designed to provide an optimal response to temperature and power perturbations, and local control laws that maintain parameters such as the margin to departure from nucleate boiling within specification. The technology described is appropriate to present-day pressurized water reactors and to the proposed multi-modular designs. The end-product of this research was a (near) real-time analytic plant-estimation code that was given the acronym POPSICLE for POwer Plant SImulator and ControlLEr. POPSICLE's core neutronics model is based on a quasi-static transient solution of the analytic nodal diffusion equations. 126 refs., 159 figs., 17 tabs.

  6. Genetic control of mammalian T-cell proliferation with synthetic RNA regulatory systems

    OpenAIRE

    Chen, Yvonne Y.; Jensen, Michael C.; Smolke, Christina D.

    2010-01-01

    RNA molecules perform diverse regulatory functions in natural biological systems, and numerous synthetic RNA-based control devices that integrate sensing and gene-regulatory functions have been demonstrated, predominantly in bacteria and yeast. Despite potential advantages of RNA-based genetic control strategies in clinical applications, there has been limited success in extending engineered RNA devices to mammalian gene-expression control and no example of their application to functional res...

  7. Open-closed-loop iterative learning control for a class of nonlinear systems with random data dropouts

    Science.gov (United States)

    Cheng, X. Y.; Wang, H. B.; Jia, Y. L.; Dong, YH

    2018-05-01

    In this paper, an open-closed-loop iterative learning control (ILC) algorithm is constructed for a class of nonlinear systems subjecting to random data dropouts. The ILC algorithm is implemented by a networked control system (NCS), where only the off-line data is transmitted by network while the real-time data is delivered in the point-to-point way. Thus, there are two controllers rather than one in the control system, which makes better use of the saved and current information and thereby improves the performance achieved by open-loop control alone. During the transfer of off-line data between the nonlinear plant and the remote controller data dropout occurs randomly and the data dropout rate is modeled as a binary Bernoulli random variable. Both measurement and control data dropouts are taken into consideration simultaneously. The convergence criterion is derived based on rigorous analysis. Finally, the simulation results verify the effectiveness of the proposed method.

  8. An open-loop controlled active lung simulator for preterm infants.

    Science.gov (United States)

    Cecchini, Stefano; Schena, Emiliano; Silvestri, Sergio

    2011-01-01

    We describe the underlying theory, design and experimental evaluation of an electromechanical analogue infant lung to simulate spontaneous breathing patterns of preterm infants. The aim of this work is to test the possibility to obtain breathing patterns of preterm infants by taking into consideration the air compressibility. Respiratory volume function represents the actuation pattern, and pulmonary pressure and flow-rate waveforms are mathematically obtained through the application of the perfect gas and adiabatic laws. The mathematical model reduces the simulation interval into a step shorter than 1 ms, allowing to consider an entire respiratory act as composed of a large number of almost instantaneous adiabatic transformations. The device consists of a spherical chamber where the air is compressed by four cylinder-pistons, moved by stepper motors, and flows through a fluid-dynamic resistance, which also works as flow-rate sensor. Specifically designed software generates the actuators motion, based on the desired ventilation parameters, without controlling the gas pneumatic parameters with a closed-loop. The system is able to simulate tidal volumes from 3 to 8 ml, breathing frequencies from 60 to 120 bpm and functional residual capacities from 25 to 80 ml. The simulated waveforms appear very close to the measured ones. Percentage differences on the tidal volume waveform vary from 7% for the tidal volume of 3 ml, down to 2.2-3.5% for tidal volumes in the range of 4-7 ml, and 1.3% for the tidal volume equal to 8 ml in the whole breathing frequency and functional residual capacity ranges. The open-loop electromechanical simulator shows that gas compressibility can be theoretically assessed in the typical pneumatic variable range of preterm infant respiratory mechanics. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

  9. Frequency-modulated laser ranging sensor with closed-loop control

    Science.gov (United States)

    Müller, Fabian M.; Böttger, Gunnar; Janeczka, Christian; Arndt-Staufenbiel, Norbert; Schröder, Henning; Schneider-Ramelow, Martin

    2018-02-01

    Advances in autonomous driving and robotics are creating high demand for inexpensive and mass-producible distance sensors. A laser ranging system (Lidar), based on the frequency-modulated continuous-wave (FMCW) method is built in this work. The benefits of an FMCW Lidar system are the low-cost components and the performance in comparison to conventional time-of-flight Lidar systems. The basic system consists of a DFB laser diode (λ= 1308 nm) and an asymmetric fiber-coupled Mach-Zehnder interferometer with a fixed delay line in one arm. Linear tuning of the laser optical frequency via injection current modulation creates a beat signal at the interferometer output. The frequency of the beat signal is proportional to the optical path difference in the interferometer. Since the laser frequency-to-current response is non-linear, a closed-loop feed-back system is designed to improve the tuning linearity, and consequently the measurement resolution. For fast active control, an embedded system with FPGA is used, resulting in a nearly linear frequency tuning, realizing a narrow peak in the Fourier spectrum of the beat signal. For free-space measurements, a setup with two distinct interferometers is built. The fully fiber-coupled Mach-Zehnder reference interferometer is part of the feed-back loop system, while the other - a Michelson interferometer - has a free-space arm with collimator lens and reflective target. A resolution of 2:0 mm for a 560 mm distance is achieved. The results for varying target distances show high consistency and a linear relation to the measured beat-frequency.

  10. The influence of internal current loop on transient response performance of I-V droop controlled paralleled DC-DC converters

    DEFF Research Database (Denmark)

    Wang, Haojie; Han, Minxiao; Guerrero, Josep M.

    2017-01-01

    The external droop control loop of I-V droop control is designed as a voltage loop with embedded virtual impedance, so the internal current loop plays a major role in the system bandwidth. Thus, in this paper, the influence of internal current loop on transient response performance of I-V droop...... controlled paralleled dc-dc converters is analyzed, which is guided and significant for its industry application. The model which is used for dynamic analysis is built, and the root locus method is used based on the model to analyze the dynamic response of the system by shifting different control parameters...

  11. Finite Element Method-Based Kinematics and Closed-Loop Control of Soft, Continuum Manipulators.

    Science.gov (United States)

    Bieze, Thor Morales; Largilliere, Frederick; Kruszewski, Alexandre; Zhang, Zhongkai; Merzouki, Rochdi; Duriez, Christian

    2018-06-01

    This article presents a modeling methodology and experimental validation for soft manipulators to obtain forward kinematic model (FKM) and inverse kinematic model (IKM) under quasi-static conditions (in the literature, these manipulators are usually classified as continuum robots. However, their main characteristic of interest in this article is that they create motion by deformation, as opposed to the classical use of articulations). It offers a way to obtain the kinematic characteristics of this type of soft robots that is suitable for offline path planning and position control. The modeling methodology presented relies on continuum mechanics, which does not provide analytic solutions in the general case. Our approach proposes a real-time numerical integration strategy based on finite element method with a numerical optimization based on Lagrange multipliers to obtain FKM and IKM. To reduce the dimension of the problem, at each step, a projection of the model to the constraint space (gathering actuators, sensors, and end-effector) is performed to obtain the smallest number possible of mathematical equations to be solved. This methodology is applied to obtain the kinematics of two different manipulators with complex structural geometry. An experimental comparison is also performed in one of the robots, between two other geometric approaches and the approach that is showcased in this article. A closed-loop controller based on a state estimator is proposed. The controller is experimentally validated and its robustness is evaluated using Lypunov stability method.

  12. A Closed-Loop Smart Control System Driving RGB Light Emitting Diodes

    KAUST Repository

    Al-Saggaf, Abeer

    2015-05-01

    The demand for control systems that are highly capable of driving solid-state optoelectronic devices has significantly increased with the advancement of their efficiency and elevation of their current consumption. This work presents a closed-loop control system that is based on a microcontroller embedded system capable of driving high power optoelectronic devices. In this version of the system, the device in the center of control is a high-power red, green, and blue light emitting diode package. The system features a graphical user interface, namely an Android mobile phone application, in which the user can easily use to vary the light color and intensity of the light-emitting device wirelessly via Bluetooth. Included in the system is a feedback mechanism constituted by a red, green, and blue color sensor through which the user can use to observe feedback color information about the emitted light. The system has many commercial application including in-door lighting and research application including plant agriculture research fields.

  13. A Closed-Loop Smart Control System Driving RGB Light Emitting Diodes

    KAUST Repository

    Al-Saggaf, Abeer

    2015-01-01

    The demand for control systems that are highly capable of driving solid-state optoelectronic devices has significantly increased with the advancement of their efficiency and elevation of their current consumption. This work presents a closed-loop control system that is based on a microcontroller embedded system capable of driving high power optoelectronic devices. In this version of the system, the device in the center of control is a high-power red, green, and blue light emitting diode package. The system features a graphical user interface, namely an Android mobile phone application, in which the user can easily use to vary the light color and intensity of the light-emitting device wirelessly via Bluetooth. Included in the system is a feedback mechanism constituted by a red, green, and blue color sensor through which the user can use to observe feedback color information about the emitted light. The system has many commercial application including in-door lighting and research application including plant agriculture research fields.

  14. Closed Loop Fuzzy Logic Controlled PV Based Cascaded Boost Five-Level Inverter System

    Science.gov (United States)

    Revana, Guruswamy; Kota, Venkata Reddy

    2018-04-01

    Recent developments in intelligent control methods and power electronics have produced PV based DC to AC converters related to AC drives. Cascaded boost converter and inverter find their way in interconnecting PV and Induction Motor. This paper deals with digital simulation and implementation of closed loop controlled five-level inverter based Photo-Voltaic (PV) system. The objective of this work is to reduce the harmonics using Multi Level Inverter based system. The DC output from the PV panel is boosted using cascaded-boost-converters. The DC output of these cascaded boost converters is applied to the bridges of the cascaded inverter. The AC output voltage is obtained by the series cascading of the output voltage of the two inverters. The investigations are done with Induction motor load. Cascaded boost-converter is proposed in the present work to produce the required DC Voltage at the input of the bridge inverter. A simple FLC is applied to CBFLIIM system. The FLC is proposed to reduce the steady state error. The simulation results are compared with the hardware results. The results of the comparison are made to show the improvement in dynamic response in terms of settling time and steady state error. Design procedure and control strategy are presented in detail.

  15. Microsatellite Attitude Determination and Control Subsystem Design and Implementation: Software-in-the-Loop Approach

    Directory of Open Access Journals (Sweden)

    Ho-Nien Shou

    2014-01-01

    Full Text Available The paper describes the development of a microsatellite attitude determination and control subsystem (ADCS and verification of its functionality by software-in-the-loop (SIL method. The role of ADCS is to provide attitude control functions, including the de-tumbling and stabilizing the satellite angular velocity, and as well as estimating the orbit and attitude information during the satellite operation. In Taiwan, Air Force Institute of Technology (AFIT, dedicating for students to design experimental low earth orbit micro-satellite, called AFITsat. For AFITsat, the operation of the ADCS consists of three modes which are initialization mode, detumbling mode, and normal mode, respectively. During the initialization mode, ADCS collects the early orbit measurement data from various sensors so that the data can be downlinked to the ground station for further analysis. As particularly emphasized in this paper, during the detumbling mode, ADCS implements the thrusters in plus-wide modulation control method to decrease the satellite angular velocity. ADCS provides the attitude determination function for the estimation of the satellite state, during normal mode. The three modes of microsatellite adopted Kalman filter algorithm estimate microsatellite attitude. This paper will discuss using the SIL validation ADCS function and verify its feasibility.

  16. A Control Law Definition of the Open Loop Stepping Electric Drive

    Directory of Open Access Journals (Sweden)

    A. B. Krasovskii

    2015-01-01

    Full Text Available The paper considers an open loop stepping electric drive (SEP with electric crushing of a step and motor fed from the controlled current invertor which should meet the requirement that is to trial a free-form guided trajectory with a split-hair accuracy. It is shown that with traditional programmed control, when the SEP forms motor phase currents of identical amplitude and variable frequency proportional to the set speed of movement, there may be considerable errors reducing a trial accuracy of the set movement trajectory, dynamic indicators provoking oscillatory processes, and even loss of motor synchronism because influence on a dynamic moment of the motor is impossible.The paper offers and proves a new way to define a control algorithm adequate to drive parameters and programmed trajectory of movement, providing error minimization and thereby increasing trial accuracy of set parameters of movement and expanding dynamic capabilities of a drive. The essence of the offered way is to use a modified mathematical model of a drive in d,q coordinates with a motor fed by the current source. In this model a programmed trajectory of movement is chosen as an input action while solving the appropriate equations defines the necessary law of control. The paper describes a developed simulation model of the stepping electric drive in the environment of MATLAB – SIMULINK, which has been used to verify and prove an efficiency of the offered method to define a control law via typical examples.It is established that no error trial of set movement trajectory in case it has breaks (jogs is technically unfeasible, as it demands an infinitely high forcing voltage of the power supply to maintain the instant positive or negative phase shifts of currents formed in the motor windings.The obtained results can be used in designing programmable precision SEPs in robots, numerically controlled machine tools, and assembly equipment.

  17. An sRNA and Cold Shock Protein Homolog-Based Feedforward Loop Post-transcriptionally Controls Cell Cycle Master Regulator CtrA.

    Science.gov (United States)

    Robledo, Marta; Schlüter, Jan-Philip; Loehr, Lars O; Linne, Uwe; Albaum, Stefan P; Jiménez-Zurdo, José I; Becker, Anke

    2018-01-01

    Adjustment of cell cycle progression is crucial for bacterial survival and adaptation under adverse conditions. However, the understanding of modulation of cell cycle control in response to environmental changes is rather incomplete. In α-proteobacteria, the broadly conserved cell cycle master regulator CtrA underlies multiple levels of control, including coupling of cell cycle and cell differentiation. CtrA levels are known to be tightly controlled through diverse transcriptional and post-translational mechanisms. Here, small RNA (sRNA)-mediated post-transcriptional regulation is uncovered as an additional level of CtrA fine-tuning. Computational predictions as well as transcriptome and proteome studies consistently suggested targeting of ctrA and the putative cold shock chaperone cspA5 mRNAs by the trans- encoded sRNA ( trans- sRNA) GspR (formerly SmelC775) in several Sinorhizobium species. GspR strongly accumulated in the stationary growth phase, especially in minimal medium (MM) cultures. Lack of the gspR locus confers a fitness disadvantage in competition with the wild type, while its overproduction hampers cell growth, suggesting that this riboregulator interferes with cell cycle progression. An eGFP-based reporter in vivo assay, involving wild-type and mutant sRNA and mRNA pairs, experimentally confirmed GspR-dependent post-transcriptional down-regulation of ctrA and cspA5 expression, which most likely occurs through base-pairing to the respective mRNA. The energetically favored secondary structure of GspR is predicted to comprise three stem-loop domains, with stem-loop 1 and stem-loop 3 targeting ctrA and cspA5 mRNA, respectively. Moreover, this work reports evidence for post-transcriptional control of ctrA by CspA5. Thus, this regulation and GspR-mediated post-transcriptional repression of ctrA and cspA5 expression constitute a coherent feed-forward loop, which may enhance the negative effect of GspR on CtrA levels. This novel regulatory circuit involving

  18. Comparison of Conventional Closed-Loop Controller with an Adaptive Controller for a Disturbed Thermodynamic System

    DEFF Research Database (Denmark)

    Alphinas, Robert A.; Hansen, Hans Henrik; Tambo, Torben

    2017-01-01

    Non-adaptive proportional controllers suffer from the ability to handle a system disturbance leading to a large steady-state error and undesired transient behavior. On the other hand, they are easy to implement and tune. This article examines whether an adaptive controller based on the MIT...

  19. Low-income minority fathers' control strategies and children's regulatory skills

    Science.gov (United States)

    Malin, Jenessa L.; Cabrera, Natasha J.; Karberg, Elizabeth; Aldoney, Daniela; Rowe, Meredith

    2015-01-01

    The current study explored the bidirectional association of children's individual characteristics, fathers' control strategies at 24-months and children's regulatory skills at pre-kindergarten (pre-K). Using a sample of low-income minority families with 2-year-olds from the Early Head Start Evaluation Research Program (n = 71) we assessed the association between child gender and vocabulary skills, fathers' control strategies at 24-months (e.g., regulatory behavior and regulatory language), and children's sustained attention and emotion regulation at pre-kindergarten. There were three main findings. First, fathers' overwhelmingly use commands (e.g., do that) to promote compliance in their 24-month old children. Second, children's vocabulary skills predict fathers' regulatory behaviors during a father-child interaction, whereas children's gender predicts fathers' regulatory language during an interaction. Third, controlling for maternal supportiveness, fathers' regulatory behaviors at 24-months predict children's sustained attention at pre-kindergarten whereas fathers' regulatory language at 24-months predicts children's emotion regulation at pre-kindergarten. Our findings highlight the importance of examining paternal contributions to children's regulatory skills. PMID:25798496

  20. Low-income, minority fathers' control strategies and their children's regulatory skills.

    Science.gov (United States)

    Malin, Jenessa L; Cabrera, Natasha J; Karberg, Elizabeth; Aldoney, Daniela; Rowe, Meredith L

    2014-01-01

    The current study explored the bidirectional association of children's individual characteristics, fathers' control strategies at 24 months, and children's regulatory skills at prekindergarten (pre-K). Using a sample of low-income, minority families with 2-year-olds from the Early Head Start Research and Evaluation Project (n = 71), we assessed the association between child gender and vocabulary skills, fathers' control strategies at 24 months (e.g., regulatory behavior and regulatory language), and children's sustained attention and emotion regulation at prekindergarten. There were three main findings. First, fathers overwhelmingly used commands (e.g., "Do that.") to promote compliance in their 24-month-old children. Second, children's vocabulary skills predicted fathers' regulatory behaviors during a father-child interaction whereas children's gender predicted fathers' regulatory language during an interaction. Third, controlling for maternal supportiveness, fathers' regulatory behaviors at 24 months predicted children's sustained attention at pre-K whereas fathers' regulatory language at 24 months predicted children's emotion regulation at pre-K. Our findings highlight the importance of examining paternal contributions to children's regulatory skills. © 2014 Michigan Association for Infant Mental Health.

  1. Conserved cis-regulatory regions in a large genomic landscape control SHH and BMP-regulated Gremlin1 expression in mouse limb buds

    Directory of Open Access Journals (Sweden)

    Zuniga Aimée

    2012-08-01

    Full Text Available Abstract Background Mouse limb bud is a prime model to study the regulatory interactions that control vertebrate organogenesis. Major aspects of limb bud development are controlled by feedback loops that define a self-regulatory signalling system. The SHH/GREM1/AER-FGF feedback loop forms the core of this signalling system that operates between the posterior mesenchymal organiser and the ectodermal signalling centre. The BMP antagonist Gremlin1 (GREM1 is a critical node in this system, whose dynamic expression is controlled by BMP, SHH, and FGF signalling and key to normal progression of limb bud development. Previous analysis identified a distant cis-regulatory landscape within the neighbouring Formin1 (Fmn1 locus that is required for Grem1 expression, reminiscent of the genomic landscapes controlling HoxD and Shh expression in limb buds. Results Three highly conserved regions (HMCO1-3 were identified within the previously defined critical genomic region and tested for their ability to regulate Grem1 expression in mouse limb buds. Using a combination of BAC and conventional transgenic approaches, a 9 kb region located ~70 kb downstream of the Grem1 transcription unit was identified. This region, termed Grem1 Regulatory Sequence 1 (GRS1, is able to recapitulate major aspects of Grem1 expression, as it drives expression of a LacZ reporter into the posterior and, to a lesser extent, in the distal-anterior mesenchyme. Crossing the GRS1 transgene into embryos with alterations in the SHH and BMP pathways established that GRS1 depends on SHH and is modulated by BMP signalling, i.e. integrates inputs from these pathways. Chromatin immunoprecipitation revealed interaction of endogenous GLI3 proteins with the core cis-regulatory elements in the GRS1 region. As GLI3 is a mediator of SHH signal transduction, these results indicated that SHH directly controls Grem1 expression through the GRS1 region. Finally, all cis-regulatory regions within the Grem1

  2. A closed-loop anesthetic delivery system for real-time control of burst suppression

    Science.gov (United States)

    Liberman, Max Y.; Ching, ShiNung; Chemali, Jessica; Brown, Emery N.

    2013-08-01

    Objective. There is growing interest in using closed-loop anesthetic delivery (CLAD) systems to automate control of brain states (sedation, unconsciousness and antinociception) in patients receiving anesthesia care. The accuracy and reliability of these systems can be improved by using as control signals electroencephalogram (EEG) markers for which the neurophysiological links to the anesthetic-induced brain states are well established. Burst suppression, in which bursts of electrical activity alternate with periods of quiescence or suppression, is a well-known, readily discernible EEG marker of profound brain inactivation and unconsciousness. This pattern is commonly maintained when anesthetics are administered to produce a medically-induced coma for cerebral protection in patients suffering from brain injuries or to arrest brain activity in patients having uncontrollable seizures. Although the coma may be required for several hours or days, drug infusion rates are managed inefficiently by manual adjustment. Our objective is to design a CLAD system for burst suppression control to automate management of medically-induced coma. Approach. We establish a CLAD system to control burst suppression consisting of: a two-dimensional linear system model relating the anesthetic brain level to the EEG dynamics; a new control signal, the burst suppression probability (BSP) defining the instantaneous probability of suppression; the BSP filter, a state-space algorithm to estimate the BSP from EEG recordings; a proportional-integral controller; and a system identification procedure to estimate the model and controller parameters. Main results. We demonstrate reliable performance of our system in simulation studies of burst suppression control using both propofol and etomidate in rodent experiments based on Vijn and Sneyd, and in human experiments based on the Schnider pharmacokinetic model for propofol. Using propofol, we further demonstrate that our control system reliably

  3. A closed-loop energy price controlling method for real-time energy balancing in a smart grid energy market

    International Nuclear Information System (INIS)

    Alagoz, B. Baykant; Kaygusuz, Asim; Akcin, Murat; Alagoz, Serkan

    2013-01-01

    Future smart grids will require a flexible, observable, and controllable network for reliable and efficient energy delivery under uncertain generation and demand conditions. One of the mechanisms for efficient and reliable energy generation is dynamic demand-responsive generation management based on energy price adjustments that creates a balance in energy markets. This study presents a closed-loop PID (proportional–integral–derivative) controller-based price control method for autonomous and real-time balancing of energy demand and generation in smart grid electricity markets. The PID control system can regulate energy prices online to respond dynamically and instantaneously to the varying energy demands of grid consumers. Independent energy suppliers in the smart grid decide whether to sell their energy to the grid according to the energy prices declared by the closed-loop PID controller system. Energy market simulations demonstrate that PID-controlled energy price regulation can effectively maintain an energy balance for hourly demand fluctuations of consumers. - Highlights: • This study presents a control theoretic approach for management of energy balance. • A closed-loop PID controller-based price controlling method is used in smart grid. • The simulation results demonstrate advantages of PID-based energy price control. • This method is appropriate for demand responsive management of smart grid markets

  4. Dual regulatory switch confers tighter control on HtrA2 proteolytic activity.

    Science.gov (United States)

    Singh, Nitu; D'Souza, Areetha; Cholleti, Anuradha; Sastry, G Madhavi; Bose, Kakoli

    2014-05-01

    High-temperature requirement protease A2 (HtrA2), a multitasking serine protease that is involved in critical biological functions and pathogenicity, such as apoptosis and cancer, is a potent therapeutic target. It is established that the C-terminal post-synaptic density protein, Drosophila disc large tumor suppressor, zonula occludens-1 protein (PDZ) domain of HtrA2 plays pivotal role in allosteric modulation, substrate binding and activation, as commonly reported in other members of this family. Interestingly, HtrA2 exhibits an additional level of functional modulation through its unique N-terminus, as is evident from 'inhibitor of apoptosis proteins' binding and cleavage. This phenomenon emphasizes multiple activation mechanisms, which so far remain elusive. Using conformational dynamics, binding kinetics and enzymology studies, we addressed this complex behavior with respect to defining its global mode of regulation and activity. Our findings distinctly demonstrate a novel N-terminal ligand-mediated triggering of an allosteric switch essential for transforming HtrA2 to a proteolytically competent state in a PDZ-independent yet synergistic activation process. Dynamic analyses suggested that it occurs through a series of coordinated structural reorganizations at distal regulatory loops (L3, LD, L1), leading to a population shift towards the relaxed conformer. This precise synergistic coordination among different domains might be physiologically relevant to enable tighter control upon HtrA2 activation for fostering its diverse cellular functions. Understanding this complex rheostatic dual switch mechanism offers an opportunity for targeting various disease conditions with tailored site-specific effector molecules. © 2014 FEBS.

  5. Optimization and analysis of the current control loop of VSCs connected to uncertain grids through LCL filters

    OpenAIRE

    Cóbreces Álvarez, Santiago

    2009-01-01

    Premio Extraordinario de Doctorado 2011 This thesis focuses on the design and analysis of the control of voltage source converters connected to the grid through LCL filters. Particularly it is centered on grids presenting uncertainty in their intrinsic dynamic parameters and their influence over the inner control loop of a grid converter: the current control. To that end, the thesis follows a three-fold discussion. Firstly, the thesis studies the grid model, its uncertain parameters and pr...

  6. Closed loop engine control for regulating NOx emissions, using a two-dimensional fuel-air curve

    Science.gov (United States)

    Bourn, Gary D.; Smith, Jack A.; Gingrich, Jess W.

    2007-01-30

    An engine control strategy that ensures that NOx emissions from the engine will be maintained at an acceptable level. The control strategy is based on a two-dimensional fuel-air curve, in which air manifold pressure (AMP) is a function of fuel header pressure and engine speed. The control strategy provides for closed loop NOx adjustment to a base AMP value derived from the fuel-air curve.

  7. Peculiarities of the Continuous Glucose Monitoring Data Stream and Their Impact on Developing Closed-Loop Control Technology

    OpenAIRE

    Kovatchev, Boris; Clarke, William

    2008-01-01

    Therapeutic advances in type 1 diabetes (T1DM) are currently focused on developing a closed-loop control system using a continuous glucose monitor (CGM), subcutaneous insulin delivery, and a control algorithm. Because a CGM assesses blood glucose indirectly (and therefore often inaccurately), it limits the effectiveness of the controller. In order to improve the quality of CGM data, a series of analyses are suggested. These analyses evaluate and compensate for CGM errors, assess risks associa...

  8. Studies on the closed-loop digital control of multi-modular reactors

    International Nuclear Information System (INIS)

    Bernard, J.A.; Henry, A.F.; Lanning, D.D.; Meyer, J.E.

    1992-11-01

    This report describes the theoretical development and the evaluation via both experiment and simulation of digital methods for the closed-loop control of power, temperature, and steam generator level in multi-modular reactors. The major conclusion of the research reported here is that the technology is currently available to automate many aspects of the operation of multi-modular plants. This will in turn minimize the number of required personnel and thus contain both operating and personnel costs, allow each module to be operated at a different power level thereby staggering the times at which refuelings would be needed, and maintain the competitiveness of US industry relative to foreign vendors who are developing and applying advanced control concepts. The technology described in this report is appropriate to the proposed multi-modular reactor designs and to present-generation pressurized water reactors. Its extension to boiling water reactors is possible provided that the commitment is made to create a real-time model of a BWR. The work reported here was performed by the Massachusetts Institute of Technology (MIT) under contract to the Oak Ridge National Laboratory (ORNL) and to the United States Department of Energy (Division of Industry and University Programs, Contract No. DE-FG07-90ER12930.)

  9. A Series Active Damper with Closed-loop Control for Stabilizing Single-phase Power-Electronics-Based Power System

    DEFF Research Database (Denmark)

    Lu, Dapeng; Wang, Xiongfei; Bai, Haofeng

    2016-01-01

    resistance through detection and resonant controller, the series active damper can suppress the resonance with its external damping character in closed-loop damping character are carried out. Simulation and experimental results are presented to verify the effectiveness of the proposed series active damper....

  10. Notification: Implementation of Executive Order 13771, “Reducing Regulation and Controlling Regulatory Costs”

    Science.gov (United States)

    Project #OA&E-FY18-0177, April 10, 2018. The OIG plans to begin preliminary research on the Office of the Administrator's Office of Policy implementation of Executive Order 13771, Reducing Regulation and Controlling Regulatory Costs.

  11. Recurrent-neural-network-based identification of a cascade hydraulic actuator for closed-loop automotive power transmission control

    International Nuclear Information System (INIS)

    You, Seung Han; Hahn, Jin Oh

    2012-01-01

    By virtue of its ease of operation compared with its conventional manual counterpart, automatic transmissions are commonly used as automotive power transmission control system in today's passenger cars. In accordance with this trend, research efforts on closed-loop automatic transmission controls have been extensively carried out to improve ride quality and fuel economy. State-of-the-art power transmission control algorithms may have limitations in performance because they rely on the steady-state characteristics of the hydraulic actuator rather than fully exploit its dynamic characteristics. Since the ultimate viability of closed-loop power transmission control is dominated by precise pressure control at the level of hydraulic actuator, closed-loop control can potentially attain superior efficacy in case the hydraulic actuator can be easily incorporated into model-based observer/controller design. In this paper, we propose to use a recurrent neural network (RNN) to establish a nonlinear empirical model of a cascade hydraulic actuator in a passenger car automatic transmission, which has potential to be easily incorporated in designing observers and controllers. Experimental analysis is performed to grasp key system characteristics, based on which a nonlinear system identification procedure is carried out. Extensive experimental validation of the established model suggests that it has superb one-step-ahead prediction capability over appropriate frequency range, making it an attractive approach for model-based observer/controller design applications in automotive systems

  12. Simulation in transient regime of a heat pump with closed-loop and on-off control

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, J.V.C. [Duke Univ., Durham, NC (United States). Dept. of Mechanical Engineering and Materials Science; Parise, J.A.R. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica

    1995-05-01

    The present work introduces a mathematical model for a heat pump with a variable-speed compressor, driven by a d.c. servomotor, operating either in closed loop by a power law control action or by the traditional on-off basis. The resulting differential and algebraic equations are integrated in time for a specified period of simulation in both designs. The results show that the closed-loop system presents significant savings in energy consumption when compared with the on-off system, under the same environmental conditions. (author)

  13. Simulation Results of Closed Loop Controlled Interline Power Flow Controller System

    Directory of Open Access Journals (Sweden)

    P. USHA RANI

    2016-01-01

    Full Text Available The Interline Power Flow Controller (IPFC is the latest generation of Flexible AC Transmission Systems (FACTS devices which can be used to control power flows of multiple transmission lines. A dispatch strategy is proposed for an IPFC operating at rated capacity, in which the power circulation between the two series converters is used as the parameter to optimize the voltage profile and power transfer. Voltage stability curves for test system are shown to illustrate the effectiveness of this proposed strategy. In this paper, a circuit model for IPFC is developed and simulation of interline power flow controller is done using the proposed circuit model. Simulation is done using MATLAB simulink and the results are presented.

  14. Power-level regulation and simulation of nonlinear pressurized water reactor core with xenon oscillation using H-infinity loop shaping control

    Directory of Open Access Journals (Sweden)

    Li Gang

    2016-01-01

    Full Text Available This investigation is to solve the power-level control issue of a nonlinear pressurized water reactor core with xenon oscillations. A nonlinear pressurized water reactor core is modeled using the lumped parameter method, and a linear model of the core is then obtained through the small perturbation linearization way. The H∞loop shapingcontrolis utilized to design a robust controller of the linearized core model.The calculated H∞loop shaping controller is applied to the nonlinear core model. The nonlinear core model and the H∞ loop shaping controller build the nonlinear core power-level H∞loop shaping control system.Finally, the nonlinear core power-level H∞loop shaping control system is simulatedconsidering two typical load processes that are a step load maneuver and a ramp load maneuver, and simulation results show that the nonlinear control system is effective.

  15. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure.

    Directory of Open Access Journals (Sweden)

    Bo Zhao

    Full Text Available This paper considers a decentralized fault tolerant control (DFTC scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO. Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations.

  16. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure

    Science.gov (United States)

    Zhao, Bo; Li, Yuanchun

    2015-01-01

    This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations. PMID:26181826

  17. Continuous improvement of the regulatory framework for the control of medical exposure

    International Nuclear Information System (INIS)

    Larcher, Ana M.; Ortiz Lopez, Pedro; Arias, Cesar; Marechal, Maria H.; Hernandez Alvarez, Ramon; Ferrer Garcia, Natividad; Castaneda Mucino, Antonia; Faller, Blanca

    2008-01-01

    One of the key elements to guide the improvement of the regulatory control is the availability of a self-assessment tool for regulatory performance. Although there is general guidance on self-assessment for regulators and users (IAEA), there is a need for more specific advice on how to address challenges and difficulties faced by regulatory bodies, when regulating radiation protection of patients. Examples of these challenges are the need for regulatory initiatives, in cooperation with health and education authorities, professional bodies and equipment suppliers, and to put in place necessary elements that are beyond responsibility of individual user of radiation, to enable them compliance with safety standards. Purpose: Within the programme of the Ibero American Forum of Nuclear and Radiation Safety Regulatory Organizations, a project to develop such a self-assessment tool for the regulatory control of medical exposure has been designed. Method: National experiences in transposing and enforcing the international radiation safety standards, as to how the requirements are included in national regulations are reviewed. Further, difficulties to the implementation of safety requirements are analyzed and a self-assessment approach and possible regulatory solutions a are presented. Results and discussion: In this study the following documents are being produced: 1) transposition of international requirements into national regulations in the six countries of the Forum, 2) difficulties to implement and enforce the requirements, 3) guidance on self-assessment of regulatory framework for medical exposure, 4) suggested contribution to the revision of international radiation safety standards. (author)

  18. Continuous Improvement of the Regulatory Framework for the Control of Medical Exposure

    International Nuclear Information System (INIS)

    Larcher, A.M.; Ortiz lopez, Pedro; Arias, Cesar; Marechal, Maria H.; Hernandez Alvarez, Ramon; Ferrer Garcia, Natividad; Castaneda Mucino, Antonia; Faller, Blanca

    2011-01-01

    Background: One of the key elements to guide the improvement of the regulatory control is the availability of a self-assessment tool for regulatory performance. Although there is general guidance on self-assessment for regulators and users (IAEA), there is a need for specific advice on how to address challenges and difficulties faced by regulatory bodies, when regulating radiation protection of patients. Examples of these challenges are the need of regulatory initiatives, in cooperation with health and education authorities, professional bodies and equipment suppliers, and to put in place necessary elements that are beyond responsibility of individual users of radiation, to enable them compliance with safety standards. Purpose: within the programme of the Ibero American Forum of Nuclear and Radiation Safety Regulatory Organizations, a project to develop such a self assessment tool for the regulatory control of medical exposure has been designed. Method: national experiences in transposing and enforcing the international radiation safety standards, as to how the requirements are included in national regulations are reviewed. Further, difficulties to the implementation of safety requirements are included in national regulations are analyzed and a self assessment approach and possible regulatory solutions are presented. Results and discussion: in tis study the following documents are being produced: 1) Transposition of international requirements into national regulations in the six countries of the Forum, 2) difficulties to implement and enforce the requirements, 3) guidance on self assessment of regulatory framework for medical exposure, 4) suggested contribution to the revision of international radiation safety standards. (authors)

  19. Hardware-in-the-Loop environment for testing and commissioning of space controllers; Hardware-in-the-Loop Umgebung zum Test und zur Inbetriebnahme von Raumreglern

    Energy Technology Data Exchange (ETDEWEB)

    Adlhoch, Alexander; Becker, Martin [Hochschule Biberach (Germany). Inst. fuer Gebaeude- und Energiesysteme

    2012-07-01

    The energy-efficient and optimal functioning of room controllers in terms of indoor air climates is influenced mainly by the control algorithm and the optimal adjustment of the parameters of controllers used in terms of space requirements. In the practical operation, deficits in the function or parameters of the controller are hardly or only with great effort metrological detectable, but have a significant impact on the energy consumption and / or the indoor climate comfort. In a hardware-in-the-loop (HIL) environment, room controllers can be examined in terms of the function under defined conditions, and different controllers can be evaluated comparatively. It is also possible to adjust the parameters of the controller before the commissioning. The HiL environment presented in the contribution under consideration consists of a model of the controlled system, a hardware coupler and a real controller to be tested. Among the spatial models, it can be selected from a plurality of different types of space which in turn can be assigned by means of different spatial parameters and environmental models. These combinations enable a replication of a test scenario corresponding to the later application. The hardware coupler provides a selection of physical inputs and outputs as well as interfaces to different bus systems (for example KNX, LON, EnOcean) for connecting different types of controllers. The construction and operation of a HIL test stand for space controller is presented based on first practical control tests. At this, the focus is on the suitability of this test environment for a variety of different controllers as well as development assistance and assistance for the adjustment of parameters. The HiL environments developed in the joint research project HiL RHK1 for the testing of space controllers, controllers for HVAC systems and refrigeration technology controllers have been developed so that the HiL environments can be coupled to a multi-HIL environment. This

  20. An improved design of virtual output impedance loop for droop-controlled parallel three-phase Voltage Source Inverters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Chen, Zhe

    2012-01-01

    -sequence virtual resistance even in the case of feeding a balanced three-phase load. Furthermore, to adapt to the variety of unbalanced loads, a dynamically-tuned negative-sequence resistance loop is designed, such that a good compromise between the quality of inverter output voltage and the performance of load......The virtual output impedance loop is known as an effective way to enhance the load sharing stability and quality of droop-controlled parallel inverters. This paper proposes an improved design of virtual output impedance loop for parallel three-phase voltage source inverters. In the approach...... sharing can be obtained. Finally, laboratory test results of two parallel three-phase voltage source inverters are shown to confirm the validity of the proposed method....

  1. Comparison of different power loop controllers for synchronous power controlled grid-interactive converters

    OpenAIRE

    Zhang, Weiyi; Remón, D.; Mir Cantarellas, Antonio; Luna Alloza, Álvaro; Rocabert Delgado, Joan; Candela García, José Ignacio; Rodríguez Cortés, Pedro

    2015-01-01

    The impact caused by the large scale penetration of renewable energy sources into electrical grid has been given an increasing concern in the past decade. Multiple challenges will occur in the future when the share of the traditional synchronous generators is reduced. One of the main issues is the lack of rotational inertia in the grid, which may cause stability issues. Therefore, the renewable energy generation plants have been asked for new control objectives and services. In this paper...

  2. Technical and regulatory challenges for digital instrumentation and control and control room systems in nuclear plants

    International Nuclear Information System (INIS)

    Torok, R.; Naser, J.; Harris, T.; Keithline, K.

    2006-01-01

    There are several unsettled technical and licensing issues in the areas of instrumentation and control (I and C), human factors, and updated control room designs that need coordinated, proactive industry attention. Some of these issues are already causing protracted regulatory reviews for existing plants, and left untreated, may cause substantial delays and increased costs for new plant combined construction and operating license approvals. Both industry and the NRC will have roles in resolving the key issues and addressing them in future design efforts and regulatory reviews. Where action is needed, the industry will want to minimize costs and risks by defining industry consensus solutions with corresponding technical bases. NEI has formed a working group to coordinate industry efforts and communications with NRC staff. The working group will also help determine priorities and coordinate both new and existing plant resources. EPRI will provide technical input and guidance for the working group. In order to be able to conduct reviews in a timely fashion, the NRC will likely need to enhance and expand staff resources as existing plants are upgraded and new plant reviews become more active. The industry initiative began with a workshop sponsored by EPRI and NEI on March 28-29, 2006, which led to the creation of the NEI working group. The working group has now identified and prioritized important generic issues, established resolution paths and schedules, and identified the roles of various stakeholders including utility companies, EPRI, NEI, vendors and the NRC. Through the course of this initiative I and C issues for both existing and new plants are being addressed. This paper describes the key I and C related technical and regulatory issues and their implications for new and operating plants, and provides a status report on the efforts to resolve them. (authors)

  3. Advanced closed loop combustion control of a LTC diesel engine based on in-cylinder pressure signals

    International Nuclear Information System (INIS)

    Carlucci, A.P.; Laforgia, D.; Motz, S.; Saracino, R.; Wenzel, S.P.

    2014-01-01

    Highlights: • We have proposed an in-cylinder pressure-based closed loop combustion control. • We have tested the control on an engine at the test bench. • We have tested the control on the engine equipping a Euro 6-compliant vehicle. • The control is effective in increasing torque stability and reduce engine noise. - Abstract: The adoption of diesel LTC combustion concepts is widely recognised as a practical way to reduce simultaneously nitric oxides and particulate emission levels from diesel internal combustion engines. However, several challenges have to be faced up when implementing diesel LTC concepts in real application vehicles. In particular, achieving acceptable performance concerning the drivability comfort, in terms of output torque stability and combustion noise during engine dynamic transients, is generally a critical point. One of the most promising solutions to improve the LTC combustion operation lays in the exploitation of closed loop combustion control, based on in-cylinder pressure signals. In this work, the application of an in-cylinder pressure-based closed loop combustion control to a Euro 6-compliant demonstrator vehicle has been developed. The main challenges deriving from the control of the LTC combustion, directly affecting the engine/vehicle performance, have been analysed in detail. In order to overcome these drawbacks, a new control function, integrated into the base closed loop system, has been designed. The performance of the new function have been experimentally tested at the engine test bench. Results showed a significant enhancement of the LTC operation, in terms of both combustion stability and noise reduction during engine transients. The new function was also implemented on a real vehicle, thus proving the potential of the new control concept in realistic operating conditions

  4. Controlling the frontier: regulatory T-cells and intestinal homeostasis.

    Science.gov (United States)

    Bollrath, Julia; Powrie, Fiona M

    2013-11-30

    The intestine represents one of the most challenging sites for the immune system as immune cells must be able to mount an efficient response to invading pathogens while tolerating the large number and diverse array of resident commensal bacteria. Foxp3(+) regulatory T-cells (Tregs) play a non-redundant role at maintaining this balance. At the same time Treg cell differentiation and function can be modulated by the intestinal microbiota. In this review, we will discuss effector mechanisms of Treg cells in the intestine and how these cells can be influenced by the intestinal microbiota. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. 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.

  6. A New Way of Controlling Parallel-Connected Inverters by Using Synchronous-Reference-Frame Virtual Impedance Loop

    DEFF Research Database (Denmark)

    Guan, Yajuan; Guerrero, Josep M.; Zhao, Xin

    2016-01-01

    A novel simple and effective autonomous current-sharing controller for parallel three-phase inverters is proposed in this paper. The proposed controller provides faster response and better accuracy in contrast to the conventional droop control, since this novel approach does not require any active...... or reactive power calculations. Instead, a synchronous-reference-frame (SRF) virtual impedance loop and an SRF-based phase-locked loop are used. Stationary analysis is provided in order to identify the inherent mechanism of the direct and quadrature output currents in relation to the voltage amplitude...... from a setup with three parallel 2.2 kW inverters verify the effectiveness of the proposed control strategy in different scenarios....

  7. WINCS Harmoni: Closed-loop dynamic neurochemical control of therapeutic interventions

    Science.gov (United States)

    Lee, Kendall H.; Lujan, J. Luis; Trevathan, James K.; Ross, Erika K.; Bartoletta, John J.; Park, Hyung Ook; Paek, Seungleal Brian; Nicolai, Evan N.; Lee, Jannifer H.; Min, Hoon-Ki; Kimble, Christopher J.; Blaha, Charles D.; Bennet, Kevin E.

    2017-04-01

    There has been significant progress in understanding the role of neurotransmitters in normal and pathologic brain function. However, preclinical trials aimed at improving therapeutic interventions do not take advantage of real-time in vivo neurochemical changes in dynamic brain processes such as disease progression and response to pharmacologic, cognitive, behavioral, and neuromodulation therapies. This is due in part to a lack of flexible research tools that allow in vivo measurement of the dynamic changes in brain chemistry. Here, we present a research platform, WINCS Harmoni, which can measure in vivo neurochemical activity simultaneously across multiple anatomical targets to study normal and pathologic brain function. In addition, WINCS Harmoni can provide real-time neurochemical feedback for closed-loop control of neurochemical levels via its synchronized stimulation and neurochemical sensing capabilities. We demonstrate these and other key features of this platform in non-human primate, swine, and rodent models of deep brain stimulation (DBS). Ultimately, systems like the one described here will improve our understanding of the dynamics of brain physiology in the context of neurologic disease and therapeutic interventions, which may lead to the development of precision medicine and personalized therapies for optimal therapeutic efficacy.

  8. An Adaptive Impedance Matching Network with Closed Loop Control Algorithm for Inductive Wireless Power Transfer.

    Science.gov (United States)

    Miao, Zhidong; Liu, Dake; Gong, Chen

    2017-08-01

    For an inductive wireless power transfer (IWPT) system, maintaining a reasonable power transfer efficiency and a stable output power are two most challenging design issues, especially when coil distance varies. To solve these issues, this paper presents a novel adaptive impedance matching network (IMN) for IWPT system. In our adaptive IMN IWPT system, the IMN is automatically reconfigured to keep matching with the coils and to adjust the output power adapting to coil distance variation. A closed loop control algorithm is used to change the capacitors continually, which can compensate mismatches and adjust output power simultaneously. The proposed adaptive IMN IWPT system is working at 125 kHz for 2 W power delivered to load. Comparing with the series resonant IWPT system and fixed IMN IWPT system, the power transfer efficiency of our system increases up to 31.79% and 60% when the coupling coefficient varies in a large range from 0.05 to 0.8 for 2 W output power.

  9. An Adaptive Impedance Matching Network with Closed Loop Control Algorithm for Inductive Wireless Power Transfer

    Science.gov (United States)

    Miao, Zhidong; Liu, Dake

    2017-01-01

    For an inductive wireless power transfer (IWPT) system, maintaining a reasonable power transfer efficiency and a stable output power are two most challenging design issues, especially when coil distance varies. To solve these issues, this paper presents a novel adaptive impedance matching network (IMN) for IWPT system. In our adaptive IMN IWPT system, the IMN is automatically reconfigured to keep matching with the coils and to adjust the output power adapting to coil distance variation. A closed loop control algorithm is used to change the capacitors continually, which can compensate mismatches and adjust output power simultaneously. The proposed adaptive IMN IWPT system is working at 125 kHz for 2 W power delivered to load. Comparing with the series resonant IWPT system and fixed IMN IWPT system, the power transfer efficiency of our system increases up to 31.79% and 60% when the coupling coefficient varies in a large range from 0.05 to 0.8 for 2 W output power. PMID:28763011

  10. Quorum-Quenching Human Designer Cells for Closed-Loop Control of Pseudomonas aeruginosa Biofilms.

    Science.gov (United States)

    Sedlmayer, Ferdinand; Jaeger, Tina; Jenal, Urs; Fussenegger, Martin

    2017-08-09

    Current antibiotics gradually lose their efficacy against chronic Pseudomonas aeruginosa infections due to development of increased resistance mediated by biofilm formation, as well as the large arsenal of microbial virulence factors that are coordinated by the cell density-dependent phenomenon of quorum sensing. Here, we address this issue by using synthetic biology principles to rationally engineer quorum-quencher cells with closed-loop control to autonomously dampen virulence and interfere with biofilm integrity. Pathogen-derived signals dynamically activate a synthetic mammalian autoinducer sensor driving downstream expression of next-generation anti-infectives. Engineered cells were able to sensitively score autoinducer levels from P. aeruginosa clinical isolates and mount a 2-fold defense consisting of an autoinducer-inactivating enzyme to silence bacterial quorum sensing and a bipartite antibiofilm effector to dissolve the biofilm matrix. The self-guided cellular device fully cleared autoinducers, potentiated bacterial antibiotic susceptibility, substantially reduced biofilms, and alleviated cytotoxicity to lung epithelial cells. We believe this strategy of dividing otherwise coordinated pathogens and breaking up their shielded stronghold represents a blueprint for cellular anti-infectives in the postantibiotic era.

  11. Very-low speed control of PMSM based on EKF estimation with closed loop optimized parameters.

    Science.gov (United States)

    Xu, Dong; Zhang, Shaoguang; Liu, Jingmeng

    2013-11-01

    When calculating the speed from the position of permanent magnet synchronous motor (PMSM), the accuracy and real-time are limited by the precision of the sensor. This problem causes crawling and jitter at very-low speed. Using the angle from the position sensor, an extended Kalman filter (EKF) designed in dq-coordinate is presented to solve this problem. The usage of position sensor simplifies the model and improves the accuracy of speed estimation. Specially, a closed loop optimal (CLO) method is devised to overcome the difficulty to adjust the parameters of the EKF. The EKF is the feedback link of speed control, CLO method is derived from the perspective of the speed step response to optimize the measurement covariance matrix and the system covariance matrix of EKF. Simulation and experimental results, comparing the low-speed performance of the EKF and sensor feedback methods, prove the effectiveness of the method to adjust the parameters of EKF and the advantages in eliminating the low speed jitter. © 2013 ISA. Published by ISA. All rights reserved.

  12. Balancing regulatory control, scientific knowledge, and public understanding.

    Science.gov (United States)

    Kingsbury, D T

    1988-01-01

    In summary, I would like to emphasize the continued need for broad and vigorous basic research, with a balance between the fundamental work that may eventually lead to commercial products and the fundamental work that is necessary for an understanding of the interaction of many types of organisms within the environment. I would like also to reiterate the need for balance in the regulatory approach so that we do not repress innovation in research and development. Over-regulation has many side effects. In addition to repressing innovation and not taking advantage of our research base, over-regulation leads to reluctance by the capital markets to invest in the future of our new industries, thereby halting their development at an early stage. At the same time, under-regulation leads to lack of confidence by the public and paralysis of the industry based on public outcry and legal proceedings. It is my personal belief that the combination of a sound approach to regulatory practice, based on current scientific knowledge, combined with appropriate communication with the public regarding the new products, will lead to an exciting future for all sectors of industry that use the new biotechnology.

  13. Introduction to Loop Heat Pipes

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Loop Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. This course will discuss operating principles and performance characteristics of a loop heat pipe. Topics include: 1) pressure profiles in the loop; 2) loop operating temperature; 3) operating temperature control; 4) loop startup; 4) loop shutdown; 5) loop transient behaviors; 6) sizing of loop components and determination of fluid inventory; 7) analytical modeling; 8) examples of flight applications; and 9) recent LHP developments.

  14. Augmenting effectiveness of control loops of a PMSG (permanent magnet synchronous generator) based wind energy conversion system by a virtually adaptive PI (proportional integral) controller

    International Nuclear Information System (INIS)

    Alizadeh, Mojtaba; Kojori, Shokrollah Shokri

    2015-01-01

    Offering substantial features, PMSG (permanent magnet synchronous generator) based WECS (wind energy conversion system) is definitely one of the most reliable and efficient ways of extracting electrical power from the wind. Like other WECSs, PMSG-based WECS (PMSG WECS) encompasses two main control loops, each equipped with PI (proportional integral) controller, to control speed and currents of the system. This work develops a virtually adaptive PI controller to enhance the performance of both main control loops of a PMSG WECS. A WNN (wavelet neural network) is proposed to be added to each closed control loop in series with PI controller. Due to having a cascade connection, the transfer function of the WNN, which is a pure gain in each time step, is multiplied by PI gains. Therefore, the value of transfer function of the WNN, and consequently, both parameters of PI controller can be changed in each time step by online training of the WNN, resulting in a virtually adaptive PI controller. The performance of the proposed controller in improving efficacy of both current and speed control loops is evaluated by simulation studies and is also compared to that of PI controller, WNNC (wavelet neural network controller), and QNNC (quantum neural network controller). - Highlights: • To propose a virtually adaptive PI controller to be used in a PMSG WECS. • Both parameters of PI controller can be changed in each time step. • The proposed controller can be used as both current or speed controller. • The plant data is not required for offline training of proposed current controller.

  15. Utilization of a hardware-in-the-loop-system for controlling the speed of an eddy current brake

    International Nuclear Information System (INIS)

    Kramer, V; Brauneis, P; Schmidt, K; Mishra, R

    2012-01-01

    Rapid prototyping with a hardware-in-the-loop (HiL) system significantly reduces the development time for controller-type testing and is widely used in various fields of engineering. In this discussion, a controller is developed for a speed control application utilizing a magnetic brake. A mathematical model is presented first that has been implemented in Matlab/ Simulink. The controller development steps are described that will form the basis of a control system for a wind turbine. A test is carried out that simulates the wind turbine inertial load.

  16. The accuracy and clinical feasibility of a new Bayesian-based closed-loop control system for propofol administration using the bispectral index as a controlled variable

    NARCIS (Netherlands)

    De Smet, Tom; Struys, Michel M. R. F.; Neckebroek, Martine M.; Van den Hauwe, Kristof; Bonte, Sjoert; Mortier, Eric P.

    2008-01-01

    BACKGROUND: Closed-loop control of the hypnotic component of anesthesia has been proposed in an attempt to optimize drug delivery. Here, we introduce a newly developed Bayesian-based, patient-individualized, model-based, adaptive control method for bispectral index (BIS) guided propofol infusion

  17. 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.

  18. 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. PMID:29163123

  19. Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila

    Science.gov (United States)

    Cattenoz, Pierre B.; Popkova, Anna; Southall, Tony D.; Aiello, Giuseppe; Brand, Andrea H.; Giangrande, Angela

    2016-01-01

    High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain–containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades. PMID:26567182

  20. A novel heart rate control model provides insights linking LF-HRV behavior to the open-loop gain.

    Science.gov (United States)

    Dvir, Hila; Bobrovsky, Ben Zion; Gabbay, Uri

    2013-09-20

    Low-frequency heart rate variability (LF-HRV) at rest has already been successfully modeled as self-sustained oscillations in a nonlinear control loop, but these models fail to simulate LF-HRV decreases either during aerobic exercise or in heart failure patients. Following control engineering practices, we assume the existence of a biological excitation (dither) within the heart rate control loop that softens the nonlinearity and studied LF-HRV behavior in a dither-embedded model. We adopted the Ottesen model with some revisions and induced a dither of high-frequency stochastic perturbations. We simulated scenarios of a healthy subject at rest and during aerobic exercise (by decreasing peripheral vascular resistance) and a heart failure patient (by decreasing stroke volume). The simulations resembled physiological LF-HRV behavior, i.e., LF-HRV decreased during aerobic exercise and in the heart failure patient. The simulations exhibited LF-HRV dependency on the open-loop gain, which is related to the product of the feedback gain and the feed forward gain. We are the first to demonstrate that LF-HRV may be dependent on the open-loop gain. Accordingly, reduced open-loop gain results in decreased LF-HRV, and vice versa. Our findings explain a well-known but unexplained observed phenomenon of reduced LF-HRV both in heart failure patients and in healthy subjects performing aerobic exercise. These findings have implications on how changes in LF-HRV can be interpreted physiologically, a necessary step towards the clinical utilization of LF-HRV. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  1. Fractal gene regulatory networks for robust locomotion control of modular robots

    DEFF Research Database (Denmark)

    Zahadat, Payam; Christensen, David Johan; Schultz, Ulrik Pagh

    2010-01-01

    Designing controllers for modular robots is difficult due to the distributed and dynamic nature of the robots. In this paper fractal gene regulatory networks are evolved to control modular robots in a distributed way. Experiments with different morphologies of modular robot are performed and the ......Designing controllers for modular robots is difficult due to the distributed and dynamic nature of the robots. In this paper fractal gene regulatory networks are evolved to control modular robots in a distributed way. Experiments with different morphologies of modular robot are performed...

  2. The regulatory control of radiation sources in Turkey

    International Nuclear Information System (INIS)

    Uslu, I.; Birol, E.

    2001-01-01

    In Turkey, the national competent authority for regulating activities involving radioactive sources is the Turkish Atomic Energy Authority, which implements the responsibility for the safety and security of radiation sources through its Radiation Health and Safety Department. The report describes the organization of the regulatory infrastructure for radiation safety in Turkey and, after a brief explanation of the current legal framework for such purpose, it refers to how the management of radiation sources is carried out and to the new provisions regarding radiation sources, including inspections of licensees and training on source safety. Finally, the report provides information on the Ikitelli radiological accident in Turkey and the current public concern about radiation sources after it happened. (author)

  3. Mammalian iron metabolism and its control by iron regulatory proteins☆

    Science.gov (United States)

    Anderson, Cole P.; Shen, Lacy; Eisenstein, Richard S.; Leibold, Elizabeth A.

    2013-01-01

    Cellular iron homeostasis is maintained by iron regulatory proteins 1 and 2 (IRP1 and IRP2). IRPs bind to iron-responsive elements (IREs) located in the untranslated regions of mRNAs encoding protein involved in iron uptake, storage, utilization and export. Over the past decade, significant progress has been made in understanding how IRPs are regulated by iron-dependent and iron-independent mechanisms and the pathological consequences of IRP2 deficiency in mice. The identification of novel IREs involved in diverse cellular pathways has revealed that the IRP–IRE network extends to processes other than iron homeostasis. A mechanistic understanding of IRP regulation will likely yield important insights into the basis of disorders of iron metabolism. This article is part of a Special Issue entitled: Cell Biology of Metals. PMID:22610083

  4. A Biological Micro Actuator: Graded and Closed-Loop Control of Insect Leg Motion by Electrical Stimulation of Muscles

    Science.gov (United States)

    Cao, Feng; Zhang, Chao; Vo Doan, Tat Thang; Li, Yao; Sangi, Daniyal Haider; Koh, Jie Sheng; Huynh, Ngoc Anh; Aziz, Mohamed Fareez Bin; Choo, Hao Yu; Ikeda, Kazuo; Abbeel, Pieter; Maharbiz, Michel M.; Sato, Hirotaka

    2014-01-01

    In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle) via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage) required to elicit leg motions was approximately 1.0 V; thus, we fixed the stimulation amplitude at 1.5 V to ensure a muscle response. The leg motions were finely graded by alternation of the stimulation frequencies: higher stimulation frequencies elicited larger leg angular displacement. A closed-loop control system was then developed, where the stimulation frequency was the manipulated variable for leg-muscle stimulation (output from the final control element to the leg muscle) and the angular displacement of the leg motion was the system response. This closed-loop control system, with an optimized proportional gain and update time, regulated the leg to set at predetermined angular positions. The average electrical stimulation power consumption per muscle group was 148 µW. These findings related to and demonstrations of the leg motion control offer promise for the future development of a reliable, low-power, biological legged machine (i.e., an insect–machine hybrid legged robot). PMID:25140875

  5. A biological micro actuator: graded and closed-loop control of insect leg motion by electrical stimulation of muscles.

    Directory of Open Access Journals (Sweden)

    Feng Cao

    Full Text Available In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage required to elicit leg motions was approximately 1.0 V; thus, we fixed the stimulation amplitude at 1.5 V to ensure a muscle response. The leg motions were finely graded by alternation of the stimulation frequencies: higher stimulation frequencies elicited larger leg angular displacement. A closed-loop control system was then developed, where the stimulation frequency was the manipulated variable for leg-muscle stimulation (output from the final control element to the leg muscle and the angular displacement of the leg motion was the system response. This closed-loop control system, with an optimized proportional gain and update time, regulated the leg to set at predetermined angular positions. The average electrical stimulation power consumption per muscle group was 148 µW. These findings related to and demonstrations of the leg motion control offer promise for the future development of a reliable, low-power, biological legged machine (i.e., an insect-machine hybrid legged robot.

  6. Interrelation between results of individual dosimetric control and regulatory control in Cuba

    International Nuclear Information System (INIS)

    Diaz Bernal, E.D.; Jova Sed, L.A.; Capote Ferrera, E.; Lopez Bejerano, G.M.

    1997-01-01

    The increasing use of various applications of ionizing radiation in Cuba made it necessary to create a harmonic system of facilities that guarantees the radiological safety of radiation workers, the public and the environment. Therefore, in 1985 a Centre of Radiation Protection and Hygiene (CPHR) was created. Thereafter, in 1991, the regulatory function and the inspection of radiological and nuclear safety was assigned to the National Centre of Nuclear Safety. The introduction of this service has provided the regulatory body with a tool to control the existing situation with respect to registration and licensing. The results of the service in the period 1994-1996 and a comparison with previous years are given. The results obtained reflect that the system of supervision in general has guaranteed keeping levels of doses low. The dose values registered demonstrate the possibility to establish in the country as a does limit an annual average dose limit of 20 mSv which might rise to but shall on no account exceed 50 mSv per year without the need for costly investment and based on organizational measures

  7. A Wirelessly-Powered Homecage With Segmented Copper Foils and Closed-Loop Power Control.

    Science.gov (United States)

    Mirbozorgi, S Abdollah; Jia, Yaoyao; Canales, Daniel; Ghovanloo, Maysam

    2016-10-01

    A new wireless electrophysiology data acquisition system, built around a standard homecage, is presented in this paper, which can power up and communicate with sensors and actuators/stimulators attached to or implanted in small freely behaving animal subjects, such as rodents. Key abilities of the energized homecage (EnerCage) system is enabling longitudinal experiments with minimal operator involvement or interruption, while providing test subjects with an enriched environment closer to their natural habitat, without the burden of being tethered or carrying bulky batteries. The magnetic resonant multi-coil design used in the new EnerCage-HC2 automatically localizes the transmitted electromagnetic power from a single transmitter (Tx) coil at the bottom of the cage toward the receiver coil (Rx), carried on/in the animal body, obviating the need for tracking the animal or switching the coils. In order to increase the resonators' quality factor (Q > 166) at the desired operating frequency of 13.56 MHz, while maintaining a high self-resonance frequency [Formula: see text], they are made of wide copper foils and optimally segmented based on a set of design rules that can be adopted for experimental arenas with different shapes and dimensions. The Rx rectified voltage is regulated at a user-defined window [Formula: see text] by a Tx-Rx closed-loop power control (CLPC) mechanism that creates a volume inside the homecage with 42 mW of power delivered to the load (PDL), and a homogeneous power transfer efficiency (PTE) plane of 14% on average at ∼7 cm height, plus stability against angular mis-alignments of up to 80°.

  8. A real-time and closed-loop control algorithm for cascaded multilevel inverter based on artificial neural network.

    Science.gov (United States)

    Wang, Libing; Mao, Chengxiong; Wang, Dan; Lu, Jiming; Zhang, Junfeng; Chen, Xun

    2014-01-01

    In order to control the cascaded H-bridges (CHB) converter with staircase modulation strategy in a real-time manner, a real-time and closed-loop control algorithm based on artificial neural network (ANN) for three-phase CHB converter is proposed in this paper. It costs little computation time and memory. It has two steps. In the first step, hierarchical particle swarm optimizer with time-varying acceleration coefficient (HPSO-TVAC) algorithm is employed to minimize the total harmonic distortion (THD) and generate the optimal switching angles offline. In the second step, part of optimal switching angles are used to train an ANN and the well-designed ANN can generate optimal switching angles in a real-time manner. Compared with previous real-time algorithm, the proposed algorithm is suitable for a wider range of modulation index and results in a smaller THD and a lower calculation time. Furthermore, the well-designed ANN is embedded into a closed-loop control algorithm for CHB converter with variable direct voltage (DC) sources. Simulation results demonstrate that the proposed closed-loop control algorithm is able to quickly stabilize load voltage and minimize the line current's THD (<5%) when subjecting the DC sources disturbance or load disturbance. In real design stage, a switching angle pulse generation scheme is proposed and experiment results verify its correctness.

  9. A Real-Time and Closed-Loop Control Algorithm for Cascaded Multilevel Inverter Based on Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Libing Wang

    2014-01-01

    Full Text Available In order to control the cascaded H-bridges (CHB converter with staircase modulation strategy in a real-time manner, a real-time and closed-loop control algorithm based on artificial neural network (ANN for three-phase CHB converter is proposed in this paper. It costs little computation time and memory. It has two steps. In the first step, hierarchical particle swarm optimizer with time-varying acceleration coefficient (HPSO-TVAC algorithm is employed to minimize the total harmonic distortion (THD and generate the optimal switching angles offline. In the second step, part of optimal switching angles are used to train an ANN and the well-designed ANN can generate optimal switching angles in a real-time manner. Compared with previous real-time algorithm, the proposed algorithm is suitable for a wider range of modulation index and results in a smaller THD and a lower calculation time. Furthermore, the well-designed ANN is embedded into a closed-loop control algorithm for CHB converter with variable direct voltage (DC sources. Simulation results demonstrate that the proposed closed-loop control algorithm is able to quickly stabilize load voltage and minimize the line current’s THD (<5% when subjecting the DC sources disturbance or load disturbance. In real design stage, a switching angle pulse generation scheme is proposed and experiment results verify its correctness.

  10. Increasing dynamic range of a fibre Bragg grating edge-filtering interrogator with a proportional control loop

    International Nuclear Information System (INIS)

    Stan, Nikola; Bailey, D C; Chadderdon, S L; Selfridge, R H; Schultz, S M; Webb, S; Zikry, M; Peters, K J

    2014-01-01

    We present a fibre Bragg grating (FBG) interrogator that uses a microcontroller board and a tunable optical filter in a proportional control loop to increase dynamic range and achieve high strain sensitivity. It is an edge-filtering interrogator with added proportional control loop that locks the operating wavelength to the mid-reflection point on the FBG spectrum. The interrogator separates low-frequency (LF) components of strain and measures them with extended dynamic range, while at the same time measuring high-frequency (HF) strain without loss in strain sensitivity. In this paper, we describe the implementation of the interrogator and analyse the characteristics of individual components, such as the speed and voltage resolution of the microcontroller and the tunable optical filter. We measure the performance of the proportional control loop at frequencies up to 1 kHz and characterize the system using control theory. We illustrate the limitation of the conventional interrogator to measure strains greater than 40 μϵ and demonstrate successful application of the proposed interrogator for simultaneous measurement of 450 μϵ LF strain at 50 Hz superimposed with 32 kHz HF strain. (paper)

  11. Regulatory control of radiation sources and radioactive materials in Ireland

    International Nuclear Information System (INIS)

    McGarry, A.T.; Fenton, D.; O'Flaherty, T.

    2001-01-01

    The primary legislation governing safety in uses of ionizing radiation in Ireland is the Radiological Protection Act, 1991. This Act provided for the establishment in 1992 of the Radiological Protection Institute of Ireland, and gives the Institute the functions and powers which enable it to be the regulatory body for all matters relating to ionizing radiation. A Ministerial Order made under the Act in 2000 consolidates previous regulations and, in particular, provides for the implementation in Irish law of the 1996 European Union Directive which lays down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionizing radiation. Under the legislation, the custody, use and a number of other activities involving radioactive substances and irradiating apparatus require a licence issued by the Institute. Currently some 1260 licences are in force. Of these, some 850 are in respect of irradiating apparatus only and are issued principally to dentists and veterinary surgeons. The remaining licences involve sealed radiation sources and/or unsealed radioactive substances used in medicine, industry or education. A schedule attached to each licence fully lists the sealed sources to which the licence applies, and also the quantities of radioactive substances which may be acquired or held under the licence. It is an offence to dispose of, or otherwise relinquish possession of, any licensable material other than in accordance with terms and conditions of the licence. Disused sources are returned to the original supplier or, where this is not possible, stored under licence by the licensee who used them. Enforcement of the licensing provisions relies primarily on the programme of inspection of licensees, carried out by the Institute's inspectors. The Institute's Regulatory Service has a complement of four inspectors, one of whom is the Manager of the Service. The Manager reports to one of the Institute's Principal

  12. PDCI Wide-Area Damping Control: PSLF Simulations of the 2016 Open and Closed Loop Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Wilches Bernal, Felipe [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pierre, Brian Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Elliott, Ryan Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schoenwald, David A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Byrne, Raymond H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Trudnowski, Daniel J. [Montana Tech of the Univ. of Montana, Butte, MT (United States); Donnelly, Matthew K. [Montana Tech of the Univ. of Montana, Butte, MT (United States)

    2017-03-01

    To demonstrate and validate the performance of the wide-are a damping control system, the project plans to conduct closed-loop tests on the PDCI in summer/fall 2016. A test plan details the open and closed loop tests to be conducted on the P DCI using the wide-area damping control system. To ensure the appropriate level of preparedness, simulations were performed in order to predict and evaluate any possible unsafe operations before hardware experiments are attempted. This report contains the result s from these simulations using the power system dynamics software PSLF (Power System Load Flow, trademark of GE). The simulations use the WECC (Western Electricity Coordinating Council) 2016 light summer and heavy summer base cases.

  13. Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

    Science.gov (United States)

    Murphy, Patrick C.

    1999-01-01

    This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high-order characteristics of the system. In this paper only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles of attack: 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of the identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the estimated closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

  14. A Biological Micro Actuator: Graded and Closed-Loop Control of Insect Leg Motion by Electrical Stimulation of Muscles

    OpenAIRE

    Cao, Feng; Zhang, Chao; Vo Doan, Tat Thang; Li, Yao; Sangi, Daniyal Haider; Koh, Jie Sheng; Huynh, Ngoc Anh; Aziz, Mohamed Fareez Bin; Choo, Hao Yu; Ikeda, Kazuo; Abbeel, Pieter; Maharbiz, Michel M.; Sato, Hirotaka

    2014-01-01

    In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle) via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage) required to elicit leg motions was approximately 1.0 V; thus, ...

  15. Unsolved problems in applying U.S. regulatory guides to control system equipment

    International Nuclear Information System (INIS)

    Stade, R.E.

    1978-01-01

    Two current problems encountered when designing control systems to the United States Regulatory Guide requirements are discussed. They are: 1) Level of surge voltages that should be specified when procuring solid state control and instrumentation systems and equipment. 2) The approach to be used qualifying equipment that must meet the aging requirements. (author)

  16. A Review of Closed-Loop Algorithms for Glycemic Control in the Treatment of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Joseph El Youssef

    2009-03-01

    Full Text Available With the discovery of insulin came a deeper understanding of therapeutic options for one of the most devastating chronic diseases of the modern era, diabetes mellitus. The use of insulin in the treatment of diabetes, especially in those with severe insulin deficiency (type 1 diabetes, with multiple injections or continuous subcutaneous infusion, has been largely successful, but the risk for short term and long term complications remains substantial. Insulin treatment decisions are based on the patient’s knowledge of meal size, exercise plans and the intermittent knowledge of blood glucose values. As such, these are open loop methods that require human input. The idea of closed loop control of diabetes treatment is quite different: automated control of a device that delivers insulin (and possibly glucagon or other medications and is based on continuous or very frequent glucose measurements. Closed loop insulin control for type 1 diabetes is not new but is far from optimized. The goal of such a system is to avoid short-term complications (hypoglycemia and long-term complications (diseases of the eyes, kidneys, nerves and cardiovascular system by mimicking the normal insulin secretion pattern of the pancreatic beta cell. A control system for automated diabetes treatment consists of three major components, (1 a glucose sensing device that serves as the afferent limb of the system; (2 an automated control unit that uses algorithms which acquires sensor input and generates treatment outputs; and (3 a drug delivery device (primarily for delivery of insulin, which serves as the system’s efferent limb. There are several major issues that highlight the difficulty of interacting with the complex unknowns of the biological world. For example, development of accurate continuous glucose monitors is crucial; the state of the art in 2009 is that such devices sometimes experience drift and are intended only to supplement information received from standard

  17. Regulatory issues of digital instrumentation and control system in Lungmen project

    International Nuclear Information System (INIS)

    Chuang, C.F.; Chou, H.P.

    2004-01-01

    The Lungmen Nuclear Power Station (LNPS) is currently under construction in Taiwan, which consists of 2 advanced boiling water reactor (ABWR) units. The instrumentation and control (IC) systems of the LNPS are based on the state-of-the-art modernized fully integrated digital design. These IC systems possess many advantages and distinguished features comparing to traditional analog IC systems, they enjoy set-point stability, self-diagnostic and automatic testing ability, fault tolerance and avoidance, low power requirements, data handling and storage capability, as well as enhanced human-machine interfaces. This paper presents regulatory overviews, regulatory requirements, current major regulatory issues, as well as the areas of regulatory concerns and the lessons learned on the digital IC systems in the Lungmen Project

  18. Automatic diagnosis of oscillating control loops in complex industrial plants; Automatische Diagnose oszillierender Regelkreise in komplexen industriellen Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Jelali, Mohieddine [VDEh-Betriebsforschungsinstitut GmbH, Duesseldorf (Germany). Abt. Prozess- und Anlagenautomatisierung; Karra, Srinivas [Applied Manufacturing Technologies, Houston, TX (United States)

    2010-07-15

    Oscillations in control loops are one of the widespread problems in the process industry. Oscillations lead to increased variability in product quality, higher energy consumption, productivity losses and increased wear of plant components. This paper presents a new approach for the automatic and comprehensive diagnosis of oscillating valve-controlled processes, based on the identification of a Hammerstein model. The proposed method not only detects and quantifies valve stiction, but is also able to find out and distinguish between faults, such as aggressive controller tuning or external oscillatory disturbances, which may occur simultaneously to stiction. (orig.)

  19. Nuclear security recommendations on nuclear and other radioactive material out of regulatory control: Recommendations

    International Nuclear Information System (INIS)

    2011-01-01

    The purpose of this publication is to provide guidance to States in strengthening their nuclear security regimes, and thereby contributing to an effective global nuclear security framework, by providing: - Recommendations to States and their competent authorities on the establishment or improvement of the capabilities of their nuclear security regimes, for carrying out effective strategies to deter, detect and respond to a criminal act, or an unauthorized act, with nuclear security implications, involving nuclear or other radioactive material that is out of regulatory control; - Recommendations to States in support of international cooperation aimed at ensuring that any nuclear or other radioactive material that is out of regulatory control, whether originating from within the State or from outside that State, is placed under regulatory control and the alleged offenders are, as appropriate, prosecuted or extradited

  20. Authority defied: need for cognitive closure influences regulatory control when resisting authority.

    Science.gov (United States)

    Damen, Tom G E; van Leeuwen, Matthijs L; Dijksterhuis, Ap; van Baaren, Rick B

    2014-08-01

    The present studies examined whether differences in need for cognitive closure (NCC) were related to differences in regulatory control when confronted with authority. In two studies, levels of regulatory control were measured when participants resisted (Study 1; N = 46) or prepared to resist the influence attempt of an authority figure (Study 2; N = 50). Results showed that resisting the influence attempt from a high-authority figure was more depleting for participants higher in NCC compared to individuals lower in NCC. However, when they were given instructions and time to prepare the act of resistance, individuals high in NCC actually showed an increase in regulatory control. Authority is usually viewed as a general principle of influence; however, the present studies suggest that there are individual differences that influence how people may experience interactions with authorities. © 2013 Wiley Periodicals, Inc.

  1. A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality

    NARCIS (Netherlands)

    Noel, E.S.; Verhoeven, M.; Lagendijk, A.K.; Tessadori, F.; Smith, K.; Choorapoikayil, S.; den Hertog, J.; Bakkers, J.

    2013-01-01

    Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind

  2. Economic Optimizing Control for Single-Cell Protein Production in a U-Loop Reactor

    DEFF Research Database (Denmark)

    Drejer, André; Ritschel, Tobias Kasper Skovborg; Jørgensen, Sten Bay

    2017-01-01

    The production of single-cell protein (SCP) in a U-loop reactor by a methanotroph is a cost efficient sustainable alternative to protein from fish meal obtained by over-fishing the oceans. SCP serves as animal feed. In this paper, we present a mathematical model that describes the dynamics of SCP...

  3. Antenna servo control system characterization: Rate loop analysis for 34-m antenna at DSS 15

    Science.gov (United States)

    Nickerson, J. A.; Cox, D. G.; Smith, H. K.; Engel, J. H.; Ahlstrom, H. G.

    1986-01-01

    The elevation and azimuth servo rate loops at the 34-m High Efficiency Deep Space Station 15 (DSS 15) are described. Time and frequency response performance criteria were measured. The results are compared to theoretically deduced performance criteria. Unexpected anomalies in the frequency response are observed and identified.

  4. Experimental and Numerical Study on the Semi-Closed Loop Control of a Planar Parallel Robot Manipulator

    Directory of Open Access Journals (Sweden)

    Yong-Lin Kuo

    2014-01-01

    Full Text Available This paper implements the model predictive control to fulfill the position control of a 3-DOF 3-RRR planar parallel manipulator. The research work covers experimental and numerical studies. First, an experimental hardware-in-the-loop system to control the manipulator is constructed. The manipulator is driven by three DC motors, and each motor has an encoder to measure the rotating angles of the motors. The entire system is designed as a semiclosed-loop control system. The controller receives the encoder signals as inputs to produce signals driving the motors. Secondly, the motor parameters are obtained by system identification, and the controllers are designed based on these parameters. Finally, the numerical simulations are performed by incorporating the manipulator kinematics and the motor dynamics; the results are compared with those from the experiments. Both results show that they are in good agreement at steady state. There are two main contributions in this paper. One is the application of the model predictive control to the planar parallel manipulator, and the other one is to overcome the effects of the uncertainties of the DC motors and the performance of the position control due to the dynamic behavior of the manipulator.

  5. Schedule-controlled learning and memory in a regulatory context

    Science.gov (United States)

    Control of behavior by the manipulation of contingencies provides powerful techniques for assessing the hazard of chemical toxicants on the nervous system. When applied to evaluate the consequences of developmental exposure, these techniques are well suited for characterizing per...

  6. Cardinal features of involuntary force variability can arise from the closed-loop control of viscoelastic afferented muscles

    Science.gov (United States)

    Laine, Christopher M.; Valero-Cuevas, Francisco J.

    2018-01-01

    Involuntary force variability below 15 Hz arises from, and is influenced by, many factors including descending neural drive, proprioceptive feedback, and mechanical properties of muscles and tendons. However, their potential interactions that give rise to the well-structured spectrum of involuntary force variability are not well understood due to a lack of experimental techniques. Here, we investigated the generation, modulation, and interactions among different sources of force variability using a physiologically-grounded closed-loop simulation of an afferented muscle model. The closed-loop simulation included a musculotendon model, muscle spindle, Golgi tendon organ (GTO), and a tracking controller which enabled target-guided force tracking. We demonstrate that closed-loop control of an afferented musculotendon suffices to replicate and explain surprisingly many cardinal features of involuntary force variability. Specifically, we present 1) a potential origin of low-frequency force variability associated with co-modulation of motor unit firing rates (i.e.,‘common drive’), 2) an in-depth characterization of how proprioceptive feedback pathways suffice to generate 5-12 Hz physiological tremor, and 3) evidence that modulation of those feedback pathways (i.e., presynaptic inhibition of Ia and Ib afferents, and spindle sensitivity via fusimotor drive) influence the full spectrum of force variability. These results highlight the previously underestimated importance of closed-loop neuromechanical interactions in explaining involuntary force variability during voluntary ‘isometric’ force control. Furthermore, these results provide the basis for a unifying theory that relates spinal circuitry to various manifestations of altered involuntary force variability in fatigue, aging and neurological disease. PMID:29309405

  7. Cardinal features of involuntary force variability can arise from the closed-loop control of viscoelastic afferented muscles.

    Science.gov (United States)

    Nagamori, Akira; Laine, Christopher M; Valero-Cuevas, Francisco J

    2018-01-01

    Involuntary force variability below 15 Hz arises from, and is influenced by, many factors including descending neural drive, proprioceptive feedback, and mechanical properties of muscles and tendons. However, their potential interactions that give rise to the well-structured spectrum of involuntary force variability are not well understood due to a lack of experimental techniques. Here, we investigated the generation, modulation, and interactions among different sources of force variability using a physiologically-grounded closed-loop simulation of an afferented muscle model. The closed-loop simulation included a musculotendon model, muscle spindle, Golgi tendon organ (GTO), and a tracking controller which enabled target-guided force tracking. We demonstrate that closed-loop control of an afferented musculotendon suffices to replicate and explain surprisingly many cardinal features of involuntary force variability. Specifically, we present 1) a potential origin of low-frequency force variability associated with co-modulation of motor unit firing rates (i.e.,'common drive'), 2) an in-depth characterization of how proprioceptive feedback pathways suffice to generate 5-12 Hz physiological tremor, and 3) evidence that modulation of those feedback pathways (i.e., presynaptic inhibition of Ia and Ib afferents, and spindle sensitivity via fusimotor drive) influence the full spectrum of force variability. These results highlight the previously underestimated importance of closed-loop neuromechanical interactions in explaining involuntary force variability during voluntary 'isometric' force control. Furthermore, these results provide the basis for a unifying theory that relates spinal circuitry to various manifestations of altered involuntary force variability in fatigue, aging and neurological disease.

  8. A Novel Dynamic Co-Simulation Analysis for Overall Closed Loop Operation Control of a Large Wind Turbine

    Directory of Open Access Journals (Sweden)

    Ching-Sung Wang

    2016-08-01

    Full Text Available A novel dynamic co-simulation methodology of overall wind turbine systems is presented. This methodology combines aerodynamics, mechanism dynamics, control system dynamics, and subsystems dynamics. Aerodynamics and turbine properties were modeled in FAST (Fatigue, Aerodynamic, Structures, and Turbulence, and ADAMS (Automatic Dynamic Analysis of Mechanical Systems performed the mechanism dynamics; control system dynamics and subsystem dynamics such as generator, pitch control system, and yaw control system were modeled and built in MATLAB/SIMULINK. Thus, this comprehensive integration of methodology expands both the flexibility and controllability of wind turbines. The dynamic variations of blades, rotor dynamic response, and tower vibration can be performed under different inputs of wind profile, and the control strategies can be verified in the different closed loop simulation. Besides, the dynamic simulation results are compared with the measuring results of SCADA (Supervisory Control and Data Acquisition of a 2 MW wind turbine for ensuring the novel dynamic co-simulation methodology.

  9. The regulatory control of radiation sources in Australia -- The challenges of a federal system

    International Nuclear Information System (INIS)

    Loy, J.; Colgan, P.

    2001-01-01

    The report refers to the challenges that Australia is facing, as a federal nation having a Commonwealth Government and six States and two territories, in establishing appropriate regulatory control of radiation sources. Information on the national inventory of radiation sources and existing regulatory infrastructure, including the system of notification, registration, licensing, inspection and enforcement, is explained in the report. The national provisions for the management of disused sources; the planning, preparedness and response to abnormal events and emergencies; the recovery of control over orphan sources; and education and training; are specifically emphasized. (author)

  10. A training rule which guarantees finite-region stability for a class of closed-loop neural-network control systems.

    Science.gov (United States)

    Kuntanapreeda, S; Fullmer, R R

    1996-01-01

    A training method for a class of neural network controllers is presented which guarantees closed-loop system stability. The controllers are assumed to be nonlinear, feedforward, sampled-data, full-state regulators implemented as single hidden-layer neural networks. The controlled systems must be locally hermitian and observable. Stability of the closed-loop system is demonstrated by determining a Lyapunov function, which can be used to identify a finite stability region about the regulator point.

  11. LQG/LTR [linear quadratic Gaussian with loop transfer recovery] robust control system design for a low-pressure feedwater heater train

    International Nuclear Information System (INIS)

    Murphy, G.V.; Bailey, J.M.

    1990-01-01

    This paper uses the linear quadratic Gaussian with loop transfer recovery (LQG/LTR) control system design method to obtain a level control system for a low-pressure feedwater heater train. The control system performance and stability robustness are evaluated for a given set of system design specifications. The tools for analysis are the return ratio, return difference, and inverse return difference singular-valve plots for a loop break at the plant output. 3 refs., 7 figs., 2 tabs

  12. Artificial Pancreas Device Systems for the Closed-Loop Control of Type 1 Diabetes: What Systems Are in Development?

    Science.gov (United States)

    Trevitt, Sara; Simpson, Sue; Wood, Annette

    2016-05-01

    Closed-loop artificial pancreas device (APD) systems are externally worn medical devices that are being developed to enable people with type 1 diabetes to regulate their blood glucose levels in a more automated way. The innovative concept of this emerging technology is that hands-free, continuous, glycemic control can be achieved by using digital communication technology and advanced computer algorithms. A horizon scanning review of this field was conducted using online sources of intelligence to identify systems in development. The systems were classified into subtypes according to their level of automation, the hormonal and glycemic control approaches used, and their research setting. Eighteen closed-loop APD systems were identified. All were being tested in clinical trials prior to potential commercialization. Six were being studied in the home setting, 5 in outpatient settings, and 7 in inpatient settings. It is estimated that 2 systems may become commercially available in the EU by the end of 2016, 1 during 2017, and 2 more in 2018. There are around 18 closed-loop APD systems progressing through early stages of clinical development. Only a few of these are currently in phase 3 trials and in settings that replicate real life. © 2015 Diabetes Technology Society.

  13. Regulatory control of radioactive sources: an international perspective

    International Nuclear Information System (INIS)

    Flakus, F.N.

    1998-01-01

    Within its Regular Programme and its Technical Co-operation Programme, the IAEA undertakes a number of activities in support of national efforts aimed at strengthening national infrastructures for the control of radiation sources. The framework of these activities is described. (author)

  14. The breakthrough of common rail system. Closed-loop control strategy using injector with built-in pressure sensor

    Energy Technology Data Exchange (ETDEWEB)

    Miyaki, Masahiko; Takeuchi, Katsuhiko; Ishizuka, Koji; Sasaki, Satoru [DENSO Corporation, Aichi-ken (Japan)

    2009-07-01

    DENSO has developed the world's first common rail system injector with built-in pressure sensor. This technology makes it possible to execute closed loop injection control in the cylinders, which has been one of the most challenging issues for diesel engine systems. Attaining both further fuel economy and emission reduction requires further technological innovation in the air system and fuel injection system. With the combustion technology that has been developed, stable combustion with high exhaust gas recirculation (EGR) is required in order to reduce nitrogen oxide's (NOx), however robustness is also required in order to handle bio-diesel and low-cetane value fuels and the range for attaining this is extremely narrow. Therefore, for the fuel injection system, in addition to conventional high pressure and high response, lifetime accuracy compensation is key. With this newly developed technology, the fuel injection rate, which determines the combustion within the engine cylinders, is directly detected and controlled in a closed loop to allow precise compensation of the injection system for its entire service life. Highly advanced injection control allows for extremely close multiple injections and variable injection rate control to be possible on the mass production level for the first time. Furthermore, the use of this technology can provide three major advantages for the overall engine system. Firstly succeeds in an expansion of the possible calibration range, which improves fuel economy and emissions, secondly it provides an improvement in the overall engine robustness and reliability. Thirdly, the use of closed loop control makes it possible to greatly reduce the man-hours required for calibration. Given this, the new DENSO common rail system using injectors with built-in pressure sensors is the first step to opening up a new era of diesel engine control. (orig.)

  15. Velocity control of a secondary controlled closed-loop hydrostatic transmission system using an adaptive fuzzy sliding mode controller

    Energy Technology Data Exchange (ETDEWEB)

    Do, Hoang Thinh; Ahn, Kyoung Kwan [University of Ulsan, Ulsan (Korea, Republic of)

    2013-03-15

    A secondary-controlled hydrostatic transmission system (SC-HST), which considered being an energy-saving system, can recuperate most of the lost vehicle kinetic energy in decelerating and braking time and it shows advantage in fuel economy improvement of vehicle. Almost secondary control units (SCU) in SC-HST inherently contain nonlinear characteristics such as dead-zone input. Therefore, it is difficult to obtain precise position or velocity control by conventional linear controllers. This problem limits the application of SC-HST in industry and mobile vehicle. This paper gives a description of SC-HST and proposes an adaptive fuzzy sliding mode controller (AFSMC) for velocity control of SCU. Experiments were carried out in the condition of disturbance load by using both the proposed controller and PID controller for the comparison and evaluation of the effectiveness of the proposed controller. The experimental results showed that the proposed controller was excellent from the standpoints of performance and stability for the velocity control of SC-HST.

  16. Design of a Closed-Loop, Bidirectional Brain Machine Interface System With Energy Efficient Neural Feature Extraction and PID Control.

    Science.gov (United States)

    Liu, Xilin; Zhang, Milin; Richardson, Andrew G; Lucas, Timothy H; Van der Spiegel, Jan

    2017-08-01

    This paper presents a bidirectional brain machine interface (BMI) microsystem designed for closed-loop neuroscience research, especially experiments in freely behaving animals. The system-on-chip (SoC) consists of 16-channel neural recording front-ends, neural feature extraction units, 16-channel programmable neural stimulator back-ends, in-channel programmable closed-loop controllers, global analog-digital converters (ADC), and peripheral circuits. The proposed neural feature extraction units includes 1) an ultra low-power neural energy extraction unit enabling a 64-step natural logarithmic domain frequency tuning, and 2) a current-mode action potential (AP) detection unit with time-amplitude window discriminator. A programmable proportional-integral-derivative (PID) controller has been integrated in each channel enabling a various of closed-loop operations. The implemented ADCs include a 10-bit voltage-mode successive approximation register (SAR) ADC for the digitization of the neural feature outputs and/or local field potential (LFP) outputs, and an 8-bit current-mode SAR ADC for the digitization of the action potential outputs. The multi-mode stimulator can be programmed to perform monopolar or bipolar, symmetrical or asymmetrical charge balanced stimulation with a maximum current of 4 mA in an arbitrary channel configuration. The chip has been fabricated in 0.18 μ m CMOS technology, occupying a silicon area of 3.7 mm 2 . The chip dissipates 56 μW/ch on average. General purpose low-power microcontroller with Bluetooth module are integrated in the system to provide wireless link and SoC configuration. Methods, circuit techniques and system topology proposed in this work can be used in a wide range of relevant neurophysiology research, especially closed-loop BMI experiments.

  17. Interpreting closed-loop learning control of molecular fragmentation in terms of wave-packet dynamics and enhanced molecular ionization

    International Nuclear Information System (INIS)

    Cardoza, David; Baertschy, Mark; Weinacht, Thomas

    2005-01-01

    We interpret a molecular fragmentation experiment using shaped, ultrafast laser pulses in terms of enhanced molecular ionization during dissociation. A closed-loop learning control experiment was performed to maximize the CF 3 + /CH 3 + production ratio in the dissociative ionization of CH 3 COCF 3 . Using ab inito molecular structure calculations and quasistatic molecular ionization calculations along with data from pump-probe experiments, we identify the primary control mechanism which is quite general and should be applicable to a broad class of molecules

  18. Genetic control and regulatory mechanisms of succinoglycan and curdlan biosynthesis in genus Agrobacterium.

    Science.gov (United States)

    Wu, Dan; Li, Ang; Ma, Fang; Yang, Jixian; Xie, Yutong

    2016-07-01

    Agrobacterium is a genus of gram-negative bacteria that can produce several typical exopolysaccharides with commercial uses in the food and pharmaceutical fields. In particular, succinoglycan and curdlan, due to their good quality in high yield, have been employed on an industrial scale comparatively early. Exopolysaccharide biosynthesis is a multiple-step process controlled by different functional genes, and various environmental factors cause changes in exopolysaccharide biosynthesis through regulatory mechanisms. In this mini-review, we focus on the genetic control and regulatory mechanisms of succinoglycan and curdlan produced by Agrobacterium. Some key functional genes and regulatory mechanisms for exopolysaccharide biosynthesis are described, possessing a high potential for application in metabolic engineering to modify exopolysaccharide production and physicochemical properties. This review may contribute to the understanding of exopolysaccharide biosynthesis and exopolysaccharide modification by metabolic engineering methods in Agrobacterium.

  19. A balance of activity in brain control and reward systems predicts self-regulatory outcomes

    OpenAIRE

    Lopez, Richard B.; Chen, Pin-Hao A.; Huckins, Jeremy F.; Hofmann, Wilhelm; Kelley, William M.; Heatherton, Todd F.

    2017-01-01

    Abstract Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily lif...

  20. Validation of gamma irradiator controls for quality and regulatory compliance

    International Nuclear Information System (INIS)

    Harding, R.B.; Pinteric, F.J.A.

    1995-01-01

    Since 1978 the U.S. Food and Drug Administration (FDA) has had both the legal authority and the current good manufacturing practice (CGMP) regulations in progress to require irradiator owners who process medical devices to produce evidence of Irradiation Process Validation. One of the key components of Irradiation Process Validation is the validation of the irradiator controls. However it is only recently that FDA audits have focussed on this component of the process validation. (author)

  1. Regulating the path from legacy recognition, through recovery to release from regulatory control.

    Science.gov (United States)

    Sneve, Malgorzata Karpow; Smith, Graham

    2015-04-01

    Past development of processes and technologies using radioactive material led to construction of many facilities worldwide. Some of these facilities were built and operated before the regulatory infrastructure was in place to ensure adequate control of radioactive material during operation and decommissioning. In other cases, controls were in place but did not meet modern standards, leading to what is now considered to have been inadequate control. Accidents and other events have occurred resulting in loss of control of radioactive material and unplanned releases to the environment. The legacy from these circumstances is that many countries have areas or facilities at which abnormal radiation conditions exist at levels that give rise to concerns about environmental and human health of potential interest to regulatory authorities. Regulation of these legacy situations is complex. This paper examines the regulatory challenges associated with such legacy management and brings forward suggestions for finding the path from: legacy recognition; implementation, as necessary, of urgent mitigation measures; development of a longer-term management strategy, through to release from regulatory control. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Closed-loop feedback control for microfluidic systems through automated capacitive fluid height sensing

    OpenAIRE

    Trumper, David; Kassis, Timothy; Griffith, Linda; Noh, Minkyun; Soenksen, Luis

    2018-01-01

    Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (<1mL) has proven to be an elusive goal, especially if direct fluid-sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to ...

  3. EURISOL-DS METEX: Cooling and Temperature Control of the Mercury Loop

    CERN Document Server

    Stefan Joray

    The cooling of the mercury loop is described on pages two, three and four. The gaps in the water jackets of the heat exchangers are too large and the cooling water capacity is too low. Convection from the wall into water is bad. The mercury temperature is too high. On page five is a proposal how the mercury temperature can be kept low and constant.

  4. Neural Network-Based State Estimation for a Closed-Loop Control Strategy Applied to a Fed-Batch Bioreactor

    Directory of Open Access Journals (Sweden)

    Santiago Rómoli

    2017-01-01

    Full Text Available The lack of online information on some bioprocess variables and the presence of model and parametric uncertainties pose significant challenges to the design of efficient closed-loop control strategies. To address this issue, this work proposes an online state estimator based on a Radial Basis Function (RBF neural network that operates in closed loop together with a control law derived on a linear algebra-based design strategy. The proposed methodology is applied to a class of nonlinear systems with three types of uncertainties: (i time-varying parameters, (ii uncertain nonlinearities, and (iii unmodeled dynamics. To reduce the effect of uncertainties on the bioreactor, some integrators of the tracking error are introduced, which in turn allow the derivation of the proper control actions. This new control scheme guarantees that all signals are uniformly and ultimately bounded, and the tracking error converges to small values. The effectiveness of the proposed approach is illustrated on the basis of simulated experiments on a fed-batch bioreactor, and its performance is compared with two controllers available in the literature.

  5. Loop capabilities in Rez for water chemistry and corrosion control of cladding and in-core components

    International Nuclear Information System (INIS)

    Kysela, J.; Zmitko, M.; Srank, J.; Vsolak, R.

    1999-01-01

    Main characteristics of LVR-15 research reactor and its irradiation facilities are presented. For testing of cladding, internals and RPV materials specialised loop are used. There are now five high pressure loops modelling PWR, WWER or BWR water environment and chemistry. Loops can be connected with instrumented in-pile channels enable slow strain rate testing, 1CT or 2CT specimens loading and electrically heated rods exposition. Reactor dosimetry including neutronic parameters measurements and calculations and mock-up experiments are used. Water chemistry control involves gas (O 2 , H 2 ) dosing system, Orbisphere H 2 /O 2 measurement, electrochemical potential (ECP) measurements and specialised analytical chemistry laboratory. For cladding corrosion studies in-pile channels with four electrically heated rods with heat flux up to 100 W/cm 2 , void fraction 5 % at the outlet, inlet temperature 320 deg. C and flow velocity 3 m/s were development and tested. For corrosion layer investigation there is eddy current measurements and PIE techniques which use crud thickness measurement, chemical analyses of the crud, optical metallography, hydrogen analysis, SEM and TEM. (author)

  6. Criteria of exemption of regulatory control for radioactive material; Criterios de exencion del control regulatorio para material radiactivo

    Energy Technology Data Exchange (ETDEWEB)

    Medrano Lopez, Marco A [Gerencia de Seguridad Radiologica, Instituto Nacional de Investigaciones Nucleares, Salazar (Mexico)

    1991-07-01

    Being based on the information contained in the 10 CFR Part 20, of the section 20.301 until the 20.306 where the mechanisms by means of which can prepare the waste of low level are indicated. While the Nuclear Regulatory Commission (NRC) it amended in the year of 1985 the Act of Politics on Low level Wastes, in particular the section 10 of the amendment of the Act, relative to the concept BRC treats those groups of radioactive waste in that their activity contents are so low that they could be exempt of the regulatory control, either liberating them toward the environment or to exempt people or organizations of the regulatory control.

  7. Impact of Automation Support on the Conflict Resolution Task in a Human-in-the-Loop Air Traffic Control Simulation

    Science.gov (United States)

    Mercer, Joey; Gomez, Ashley; Gabets, Cynthia; Bienert, Nancy; Edwards, Tamsyn; Martin, Lynne; Gujral, Vimmy; Homola, Jeffrey

    2016-01-01

    To determine the capabilities and limitations of human operators and automation in separation assurance roles, the second of three Human-in-the-Loop (HITL) part-task studies investigated air traffic controllers ability to detect and resolve conflicts under varying task sets, traffic densities, and run lengths. Operations remained within a single sector, staffed by a single controller, and explored, among other things, the controllers responsibility for conflict resolution with or without their involvement in the conflict detection task. Furthermore, these conditions were examined across two different traffic densities; 1x (current-day traffic) and a 20 increase above current-day traffic levels (1.2x). Analyses herein offer an examination of the conflict resolution strategies employed by controllers. In particular, data in the form of elapsed time between conflict detection and conflict resolution are used to assess if, and how, the controllers involvement in the conflict detection task affected the way in which they resolved traffic conflicts.

  8. Evaluation of the performance of indirect control of many DSRs using hardware-in-the-loop simulations

    DEFF Research Database (Denmark)

    Sossan, Fabrizio; Bindner, Henrik W.

    2012-01-01

    Controlling the power consumption of many Demand Side Resources, DSRs, will be required in the future power system where a big share of the electric energy will be produced using stochastic renewable sources and the conventional power plants might not have the flexibility of providing all...... the regulating power. Indirect control of demand side resources is supposed to shift the electric power consumption of each single unit through broadcasting of a control signal; the flexibility in the aggregated power consumption can be used for supplying balancing power to the electric power system. Indirect......-time power readings from the units can be performed. The aim of the paper is to discuss the performance of an emulated closed loop control using an estimator for predicting the aggregate power response and a regulator. By using these components it is possible to produce a control signal to broadcast...

  9. Analysis of Multi-Loop Control Structures of Dividing-Wall Distillation Columns Using a Fundamental Model

    Directory of Open Access Journals (Sweden)

    Salvador Tututi-Avila

    2014-02-01

    Full Text Available Dividing-wall columns (DWCs have significant potential as energy-efficient processes for the separation of multicomponent mixtures. However, in addition to an efficient steady state design, dynamics and control also play a major part for the success of a technology. This is especially so for complex distillation systems. This paper investigates the dynamics of a dividing wall column used for the separation of ternary mixtures. A detailed dynamic first principles-based model of the column I s developed in gPROMS. The model is used to generate data used for control loop pairing via the Relative Gain Array (RGA, and controller parameters are found by using Internal Model Control (IMC tuning. The best control structures for DWC systems, involving four different ternary mixtures, and two different feed compositions for each mixture, are investigated.

  10. THE ROLE OF SELF-REGULATORY AUDITING ASSOCIATIONS IN ARRANGEMENT OF AUDIT ACTIVITIES QUALITY CONTROL

    Directory of Open Access Journals (Sweden)

    Zinaida P. Arharova

    2013-01-01

    Full Text Available The role of self-regulatory organizations in audit activities quality control is revealed in this article. Creation of a united audit association is the basis of certain regulating and auditing functions transfer from the government to the public sector.

  11. Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

    International Nuclear Information System (INIS)

    1997-11-01

    The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference

  12. Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference. Refs, figs, tabs.

  13. An overview of exhaust emissions regulatory requirements and control technology for stationary natural gas engines

    International Nuclear Information System (INIS)

    Ballard, H.N.; Hay, S.C.; Shade, W.N. Jr.

    1992-01-01

    In this paper a practical overview of stationary natural gas engine exhaust emissions control technology and trends in emissions regulatory requirements is presented. Selective and non-selective catalytic reduction and lean burn technologies are compared. Particular emphasis is focussed on implications of the Clean Air Act of 1990. Recent emissions reduction conversion kit developments and a practical approach to continuous monitoring are discussed

  14. Enforcement of radiation safety standards and experience in the regulatory control of exposures

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamurthi, T N [Health and Safety Div., Atomic Energy Regulatory Board, Mumbai (India)

    1997-11-01

    Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author). 3 refs, 2 tabs.

  15. Enforcement of radiation safety standards and experience in the regulatory control of exposures

    International Nuclear Information System (INIS)

    Krishnamurthi, T.N.

    1997-01-01

    Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author)

  16. International principles for exemption from regulatory control and their application to waste management

    International Nuclear Information System (INIS)

    Linsley, G.S.

    1989-01-01

    This paper describes the main features of the international consensus on principles for exempting radiation sources and practices from regulatory control reached at a meeting in Vienna in March 1988. Some remaining problems, both of a philosophical and technical nature especially related to the application of the principles to radioactive waste disposal, are discussed

  17. A prospective randomized controlled trial comparing early postoperative complications in patients undergoing loop colostomy with and without a stoma rod.

    Science.gov (United States)

    Franklyn, J; Varghese, G; Mittal, R; Rebekah, G; Jesudason, M R; Perakath, B

    2017-07-01

    A stoma rod or bridge has been traditionally placed under the bowel loop while constructing a loop colostomy. This is believed to prevent stomal retraction and provide better faecal diversion. However, the rod can cause complications such as mucosal congestion, oedema and necrosis. This single-centre prospective randomized controlled trial compared outcomes after creation of loop colostomy with and without a supporting stoma rod. The primary outcome studied was stoma retraction rate; other stoma-related complications were studied as secondary outcomes. One hundred and fifty-one patients were randomly allotted to one of two arms, colostomy with or without a supporting rod. Postoperative complications such as retraction, mucocutaneous separation, congestion and re-exploration for stoma-related complications were recorded. There was no difference in the stoma retraction rate between the two arms (8.1% in the rod arm and 6.6% in the no-rod arm; P = 0.719). Stomal necrosis (10.7% vs 1.3%; P = 0.018), oedema (23% vs 3.9%; P = 0.001), congestion (20.3% vs 2.6%; P = 0.001) and re-admission rates (8.5% vs 0%; P = 0.027) were significantly increased in the arm randomized to the rod. The stoma rod does not prevent stomal retraction. However, complication rates are significantly higher when a stoma rod is used. Routine use of a stoma rod for construction of loop colostomy can be avoided. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

  18. Neural signal processing and closed-loop control algorithm design for an implanted neural recording and stimulation system.

    Science.gov (United States)

    Hamilton, Lei; McConley, Marc; Angermueller, Kai; Goldberg, David; Corba, Massimiliano; Kim, Louis; Moran, James; Parks, Philip D; Sang Chin; Widge, Alik S; Dougherty, Darin D; Eskandar, Emad N

    2015-08-01

    A fully autonomous intracranial device is built to continually record neural activities in different parts of the brain, process these sampled signals, decode features that correlate to behaviors and neuropsychiatric states, and use these features to deliver brain stimulation in a closed-loop fashion. In this paper, we describe the sampling and stimulation aspects of such a device. We first describe the signal processing algorithms of two unsupervised spike sorting methods. Next, we describe the LFP time-frequency analysis and feature derivation from the two spike sorting methods. Spike sorting includes a novel approach to constructing a dictionary learning algorithm in a Compressed Sensing (CS) framework. We present a joint prediction scheme to determine the class of neural spikes in the dictionary learning framework; and, the second approach is a modified OSort algorithm which is implemented in a distributed system optimized for power efficiency. Furthermore, sorted spikes and time-frequency analysis of LFP signals can be used to generate derived features (including cross-frequency coupling, spike-field coupling). We then show how these derived features can be used in the design and development of novel decode and closed-loop control algorithms that are optimized to apply deep brain stimulation based on a patient's neuropsychiatric state. For the control algorithm, we define the state vector as representative of a patient's impulsivity, avoidance, inhibition, etc. Controller parameters are optimized to apply stimulation based on the state vector's current state as well as its historical values. The overall algorithm and software design for our implantable neural recording and stimulation system uses an innovative, adaptable, and reprogrammable architecture that enables advancement of the state-of-the-art in closed-loop neural control while also meeting the challenges of system power constraints and concurrent development with ongoing scientific research designed

  19. Design project of the dosimetry control system in the independent CO2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels, Vol. V

    International Nuclear Information System (INIS)

    1964-01-01

    Design project of the dosimetry control system in the independent CO 2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels includes the following: calculations of CO 2 gas activity, design of the dosimetry control system, review of the changes that should be done in the RA reactor building for installing the independent CO 2 loop, specification of the materials with cost estimation, engineering drawings of the system [sr

  20. The Regulatory Networks That Control Clostridium difficile Toxin Synthesis

    Science.gov (United States)

    Martin-Verstraete, Isabelle; Peltier, Johann; Dupuy, Bruno

    2016-01-01

    The pathogenic clostridia cause many human and animal diseases, which typically arise as a consequence of the production of potent exotoxins. Among the enterotoxic clostridia, Clostridium difficile is the main causative agent of nosocomial intestinal infections in adults with a compromised gut microbiota caused by antibiotic treatment. The symptoms of C. difficile infection are essentially caused by the production of two exotoxins: TcdA and TcdB. Moreover, for severe forms of disease, the spectrum of diseases caused by C. difficile has also been correlated to the levels of toxins that are produced during host infection. This observation strengthened the idea that the regulation of toxin synthesis is an important part of C. difficile pathogenesis. This review summarizes our current knowledge about the regulators and sigma factors that have been reported to control toxin gene expression in response to several environmental signals and stresses, including the availability of certain carbon sources and amino acids, or to signaling molecules, such as the autoinducing peptides of quorum sensing systems. The overlapping regulation of key metabolic pathways and toxin synthesis strongly suggests that toxin production is a complex response that is triggered by bacteria in response to particular states of nutrient availability during infection. PMID:27187475

  1. U.S. Nuclear Regulatory Commission bases for control of solid materials

    International Nuclear Information System (INIS)

    Meck, R.A.; Cardille, F.P.; Feldman, C.; Gnugnoli, G.N.; Huffert, A.M.; Klementowicz, S.P.

    2002-01-01

    The U.S. Nuclear Regulatory Commission (NRC) is considering whether to proceed with rulemaking on the control of solid materials with very low levels of associated radioactivity. The current implementation of clearance by NRC licensees is the context for the decision. Inputs to the decision include information gathering efforts of the Commission in the areas of public workshops, dose assessments and inventories, the recommendations of the National Academies' National Research Council (NAs) on regulatory alternatives, and participation in international efforts by the International Atomic Energy Agency (IAEA). (author)

  2. Development of Digital Hysteresis Current Control with PLL Loop Gain Compensation Strategy for PWM Inverters with Constant Switching Frequency

    Directory of Open Access Journals (Sweden)

    N. Belhaouchet

    2008-03-01

    Full Text Available Hysteresis current control is one of the simplest techniques used to control the magnitude and phase angle of motor current for motor drives systems. However, this technique presents several disadvantages such as operation at variable switching frequency which can reveal problems of filtering, interference between the phases in the case of the three-phase systems with insulated neutral connection or delta connection, and irregularity of the modulation pulses which especially causes an acoustic noise on the level of the machine for the high power drive. In this paper, a new technique is proposed for a variable-hysteresis-band controller based on dead beat control applied to three phase voltage source PWM inverters feeding AC motors. Its main aim is firstly ensure a constant switching frequency and secondly the synchronization of modulation pulses using the phase-locked-loop with loop gain compensation in order to ensure a better stability. The behavior of the proposed technique is verified by simulation.

  3. High Performance Motion-Planner Architecture for Hardware-In-the-Loop System Based on Position-Based-Admittance-Control

    Directory of Open Access Journals (Sweden)

    Francesco La Mura

    2018-02-01

    Full Text Available This article focuses on a Hardware-In-the-Loop application developed from the advanced energy field project LIFES50+. The aim is to replicate, inside a wind gallery test facility, the combined effect of aerodynamic and hydrodynamic loads on a floating wind turbine model for offshore energy production, using a force controlled robotic device, emulating floating substructure’s behaviour. In addition to well known real-time Hardware-In-the-Loop (HIL issues, the particular application presented has stringent safety requirements of the HIL equipment and difficult to predict operating conditions, so that extra computational efforts have to be spent running specific safety algorithms and achieving desired performance. To meet project requirements, a high performance software architecture based on Position-Based-Admittance-Control (PBAC is presented, combining low level motion interpolation techniques, efficient motion planning, based on buffer management and Time-base control, and advanced high level safety algorithms, implemented in a rapid real-time control architecture.

  4. Variable Step Closed Loop Power Control with Space Diversity for Low Elevation Angle High Altitude Platforms Communication Channel [Langkah Variabel Kontrol Daya Loop Tertutup dengan Keragaman Ruang untuk Sudut Elevasi Rendah pada Kanal Komunikasi HAPs

    Directory of Open Access Journals (Sweden)

    Iskandar Iskandar

    2016-07-01

    Full Text Available This paper proposes variable step closed loop power control algorithm combined with space diversity to improve the performance of High Altitude Platforms (HAPs communication at low elevation angle using Code Division Multiple Access (CDMA. In this contribution, we first develop HAPs channel model which is derived from experimental measurement. From our experiment, we found HAPs channel characteristic can be modeled as a Ricean distribution because the presence of line of sight path. Different elevation angle resulting different K factor value.  This value is then used in Signal to Interference Ratio (SIR based closed loop power control evaluation. The variable step algorithm is simulated under various elevation angles with different speed of mobile user. The performance is presented in terms of user elevation angle, user speed, step size and space diversity order. We found that the performance of variable step closed-loop power control less effective at low elevation angle. However our simulation shows that space diversity is able to improve the performance of closed loop power control for HAPs channel at low elevation angle.*****Kajian ini mengusulkan suatu algoritma kontrol daya langkah variabel loop tertutup dikombinasikan dengan keragaman ruang untuk meningkatkan kinerja komunikasi High Altitude Platforms(HAPs pada sudut elevasi rendah menggunakan Code Division Multiple Access (CDMA. Kami berkontribusi untuk mengembangkan model kanal HAPs yang berasal dari pengukuran eksperimental sebelumnya. Dari percobaan tersebut, kami menemukan karakteristik kanal HAPs yang dapat dimodelkan sebagai distribusi Ricean karena kehadiran jalur tanpa penghalang. Eksperimen menunjukkan bahwa perbedaan sudut elevasi menghasilkan perbedaan nilai factor K. Nilai ini kemudian digunakan dalam Signal to Interference Ratio (SIR berbasiskan evaluasi kontrol daya loop tertutup. Algoritma langkah variabel disimulasikan dibawah sudut elevasi yang berbeda dengan kecepatan

  5. Closed-Loop Control of Vortex Formation in Separated Flows with Application to Micro Air Vehicles

    Science.gov (United States)

    2010-10-25

    to roppremon of disturbance» acting on the output of the closed loop Fatally. & can be interpreted as a feedforward function (Skngertad...aidividual coruroi I. be manuall ) «et by the incr The option» set by each mode are listed in Table 7 -f-.ttcmal Tngger" refer» to whether the timing...tnuurc vdocimevy wii the three -duncrruOBaJ charactowalioo of two-phawe tiowa’. .(eViomrirawn/ Srmice and r<raav>/cxi 13(51. 6«’ 694 IRL: Htp , J* dot

  6. Morphing Wing-Tip Open Loop Controller and its Validation During Wind Tunnel Tests at the IAR-NRC

    Directory of Open Access Journals (Sweden)

    Mohamed Sadok GUEZGUEZ

    2016-09-01

    Full Text Available In this project, a wing tip of a real aircraft was designed and manufactured. This wing tip was composed of a wing and an aileron. The wing was equipped with a composite skin on its upper surface. This skin changed its shape (morphed by use of 4 electrical in-house developed actuators and 32 pressure sensors. These pressure sensors measure the pressures, and further the loads on the wing upper surface. Thus, the upper surface of the wing was morphed using these actuators with the aim to improve the aerodynamic performances of the wing-tip. Two types of ailerons were designed and manufactured: one aileron is rigid (non-morphed and one morphing aileron. This morphing aileron can change its shape also for the aerodynamic performances improvement. The morphing wing-tip internal structure is designed and manufactured, and is presented firstly in the paper. Then, the modern communication and control hardware are presented for the entire morphing wing tip equipped with actuators and sensors having the aim to morph the wing. The calibration procedure of the wing tip is further presented, followed by the open loop controller results obtained during wind tunnel tests. Various methodologies of open loop control are presented in this paper, and results obtained were obtained and validated experimentally through wind tunnel tests.

  7. Drifts and Environmental Disturbances in Atomic Clock Subsystems: Quantifying Local Oscillator, Control Loop, and Ion Resonance Interactions.

    Science.gov (United States)

    Enzer, Daphna G; Diener, William A; Murphy, David W; Rao, Shanti R; Tjoelker, Robert L

    2017-03-01

    Linear ion trap frequency standards are among the most stable continuously operating frequency references and clocks. Depending on the application, they have been operated with a variety of local oscillators (LOs), including quartz ultrastable oscillators, hydrogen-masers, and cryogenic sapphire oscillators. The short-, intermediate-, and long-term stability of the frequency output is a complicated function of the fundamental performances, the time dependence of environmental disturbances, the atomic interrogation algorithm, the implemented control loop, and the environmental sensitivity of the LO and the atomic system components. For applications that require moving these references out of controlled lab spaces and into less stable environments, such as fieldwork or spaceflight, a deeper understanding is needed of how disturbances at different timescales impact the various subsystems of the clock and ultimately the output stability. In this paper, we analyze which perturbations have an impact and to what degree. We also report on a computational model of a control loop, which keeps the microwave source locked to the ion resonance. This model is shown to agree with laboratory measurements of how well the feedback removes various disturbances and also with a useful analytic approach we developed for predicting these impacts.

  8. Closed-Loop Control of Humidification for Artifact Reduction in Capacitive ECG Measurements.

    Science.gov (United States)

    Leicht, Lennart; Eilebrecht, Benjamin; Weyer, Soren; Leonhardt, Steffen; Teichmann, Daniel

    2017-04-01

    Recording biosignals without the need for direct skin contact offers new opportunities for ubiquitous health monitoring. Electrodes with capacitive coupling have been shown to be suitable for the monitoring of electrical potentials on the body surface, in particular ECG. However, due to triboelectric charge generation and motion artifacts, signal and thus diagnostic quality is inferior to galvanic coupling. Active closed-loop humidification of capacitive electrodes is proposed in this work as a new concept to improve signal quality. A capacitive ECG recording system integrated into a common car seat is presented. It can regulate the micro climate at the interface of electrode and patient by actively dispensing water vapour and monitoring humidity in a closed-loop approach. As a regenerative water reservoir, silica gel is used. The system was evaluated with respect to subjective and objective ECG signal quality. Active humidification was found to have a significant positive effect in case of previously poor quality. Also, it had no diminishing effect in case of already good signal quality.

  9. Alternative approaches to pollution control and waste management: Regulatory and economic instruments

    International Nuclear Information System (INIS)

    Bernstein, J.D.

    1993-01-01

    The purpose of the paper is to present an overview of the most common strategies and policy instruments (that is, regulatory and economic) used in developed and developing countries to achieve pollution control and waste management objectives. Although this topic has been at the center of theoretical controversy both within and outside the World Bank, the paper is not intended to contribute to this debate. Rather, its purpose is to explore how regulatory and economic instruments are used to control air and water pollution, protect ground water, and manage solid and hazardous wastes. The paper is directed to policy makers at the national, state, and local levels of government, as well as to other parties responsible for pollution control and waste management programs

  10. Development and implementation of the regulatory control of sources in Latin American Model Project countries

    International Nuclear Information System (INIS)

    Ferruz Cruz, P.

    2001-01-01

    After a general assessment of the situation regarding radiation safety and the radiation protection infrastructure in Latin American countries, several of them were invited to participate in a Model Project oriented, in some cases, towards establishing a mechanism for national regulatory control of radiation sources, and in others, towards upgrading their national control programme. All these activities aimed at reaching an effective and sustainable radiation protection infrastructure based on international basic safety standards. The paper presents a general overview of the current situation with regard to radiation protection within the Model Project countries in Latin America after almost five years of activities. It includes: the implementation of regulatory issues; the control of occupational, medical and public exposures; emergency response and waste safety issues. The paper also presents some lessons learned during implementation concerning the numerous activities involved in this interregional project. (author)

  11. Studies for improvement of regulatory control on the radioactive effluent released from nuclear facilities

    International Nuclear Information System (INIS)

    Cheong, Jae Hak; Park, H. M.; Song, M. C.; Lee, K. H.; Jang, J. K.; Chun, J. K.; Jeong, K. H.

    2005-05-01

    This report contains the second-year results of the research project titled 'Studies for Improvement of Regulatory Control on the Radioactive Effluent Released from Nuclear Facilities' and mainly provides technical and strategic approaches to improve performance of regulatory control on the gaseous effluent released from domestic nuclear facilities. The main result contained here includes overview and technical bases of radioactive gaseous effluent control (Chapter 1), reconsideration of the sensitivity requirements for measurement of radioactivity in gaseous effluent sample (Chapter 2), uncertainty analysis of the calculated radioactivity in gaseous effluent (Chapter 3), and improvement of quantification method of noble gas releases (Chapter 4). In addition, analysis of the impact due to combined sampling of particulate from multiple release points (Chapter 5), comparison of domestic nuclear reactors gaseous effluent data to foreign PWRs (Chapter 6), standardized sampling technique for collection of gaseous tritium (Chapter 7), and application of Xe-133 equivalent concept to gaseous effluent control (Chapter 8) are also provided. As a whole, this report provides a generic approach to improve the performance of regulatory control on the gaseous effluent. Therefore, actual enforcement of the recommendations should be preceded by establishment of a series of action plans reflecting on the site- and facility-specific design and operational features

  12. Comparative genomics of metabolic capacities of regulons controlled by cis-regulatory RNA motifs in bacteria.

    Science.gov (United States)

    Sun, Eric I; Leyn, Semen A; Kazanov, Marat D; Saier, Milton H; Novichkov, Pavel S; Rodionov, Dmitry A

    2013-09-02

    In silico comparative genomics approaches have been efficiently used for functional prediction and reconstruction of metabolic and regulatory networks. Riboswitches are metabolite-sensing structures often found in bacterial mRNA leaders controlling gene expression on transcriptional or translational levels.An increasing number of riboswitches and other cis-regulatory RNAs have been recently classified into numerous RNA families in the Rfam database. High conservation of these RNA motifs provides a unique advantage for their genomic identification and comparative analysis. A comparative genomics approach implemented in the RegPredict tool was used for reconstruction and functional annotation of regulons controlled by RNAs from 43 Rfam families in diverse taxonomic groups of Bacteria. The inferred regulons include ~5200 cis-regulatory RNAs and more than 12000 target genes in 255 microbial genomes. All predicted RNA-regulated genes were classified into specific and overall functional categories. Analysis of taxonomic distribution of these categories allowed us to establish major functional preferences for each analyzed cis-regulatory RNA motif family. Overall, most RNA motif regulons showed predictable functional content in accordance with their experimentally established effector ligands. Our results suggest that some RNA motifs (including thiamin pyrophosphate and cobalamin riboswitches that control the cofactor metabolism) are widespread and likely originated from the last common ancestor of all bacteria. However, many more analyzed RNA motifs are restricted to a narrow taxonomic group of bacteria and likely represent more recent evolutionary innovations. The reconstructed regulatory networks for major known RNA motifs substantially expand the existing knowledge of transcriptional regulation in bacteria. The inferred regulons can be used for genetic experiments, functional annotations of genes, metabolic reconstruction and evolutionary analysis. The obtained genome

  13. Special power supply and control system for the gas-cooled fast reactor-core flow test loop

    International Nuclear Information System (INIS)

    Hudson, T.L.

    1981-09-01

    The test bundle in the Gas-Cooled Fast Reactor-Core Flow Test Loop (GCFR-CFTL) requires a source of electrical power that can be controlled accurately and reliably over a wide range of steady-state and transient power levels and skewed power distributions to simulate GCFR operating conditions. Both ac and dc power systems were studied, and only those employing silicon-controlled rectifiers (SCRs) could meet the requirements. This report summarizes the studies, tests, evaluations, and development work leading to the selection. it also presents the design, procurement, testing, and evaluation of the first 500-kVa LMPL supply. The results show that the LMPL can control 60-Hz sine wave power from 200 W to 500 kVA

  14. Design, assembly, and initial use of a digital system for the closed-loop control of a nuclear research reactor

    International Nuclear Information System (INIS)

    Kwok, K.S.; Bernard, J.A.; Lanning, D.D.

    1991-01-01

    In this paper the design, implementation, and initial testing of a multiple-computer/single-task system for the closed-loop control of a nuclear research reactor is described. A major advantage of the multiple-computer approach is that generic safety-related software that remains invariant can be separated from the control law software that is updated as plant procedures change. This facilitates software validation. Also, this approach allows both real-time operation and high numerical throughput. System compatibility was achieved through design of a special passive back plane which enabled the otherwise incompatible components to be operated in an integrated system. This multiple-computer system, which was designated as the Advanced Control Computer System (ACCS), has been installed on the 5-MWt MIT Research Reactor. In addition to a description of both the system and its associated hardware and software interfaces, experimental results are presented from its initial trials

  15. Exemption from Regulatory Control of Goods Containing Small Amounts of Radioactive Material

    International Nuclear Information System (INIS)

    2012-01-01

    Small amounts of radioactive material may be added to various goods for functional reasons. Several such items are currently available for either professional or personal use. These include ionization chamber smoke detectors, thoriated-tungsten welding rods, luminous dials, electrical devices and electric discharge lamps. Some of these goods may be intended for particular types of market such as cinemas or other places to which the public may have access, but they are unlikely to be provided directly to members of the public. Other goods may be intended for wide scale use and therefore readily available on the market as consumer products through commercial outlets where personal and household products are normally purchased. Members of the public may be exposed to ionizing radiation as a consequence of activities such as transport, storage, use and disposal of such goods. The IAEA safety standards provide the basic requirements for regulatory control of such goods. The most relevant documents are the Governmental, Legal and Regulatory Framework for Safety and the International Basic Safety Standards (hereafter referred to as the BSS). These requirements include notification of a practice to the regulatory body and authorization of the practice by the regulatory body. Provision is made for the exemption of practices from these and other regulatory requirements based on general criteria given in the BSS or any exemption levels specified by the regulatory body on the basis of these criteria. The BSS, which are jointly sponsored by the IAEA and several other international organizations, apply to all facilities and all activities for peaceful purposes that give rise to exposure to radiation. In the interest of harmonization of approaches among Member States, some guidance on the application of the criteria for exemption has been provided in a number of Safety Guides, e.g. Regulatory Control of Radiation Sources, IAEA Safety Standards Series No. GS-G-1.5 (2004) and the

  16. Model-based rational feedback controller design for closed-loop deep brain stimulation of Parkinson's disease

    Science.gov (United States)

    Gorzelic, P.; Schiff, S. J.; Sinha, A.

    2013-04-01

    Objective. To explore the use of classical feedback control methods to achieve an improved deep brain stimulation (DBS) algorithm for application to Parkinson's disease (PD). Approach. A computational model of PD dynamics was employed to develop model-based rational feedback controller design. The restoration of thalamocortical relay capabilities to patients suffering from PD is formulated as a feedback control problem with the DBS waveform serving as the control input. Two high-level control strategies are tested: one that is driven by an online estimate of thalamic reliability, and another that acts to eliminate substantial decreases in the inhibition from the globus pallidus interna (GPi) to the thalamus. Control laws inspired by traditional proportional-integral-derivative (PID) methodology are prescribed for each strategy and simulated on this computational model of the basal ganglia network. Main Results. For control based upon thalamic reliability, a strategy of frequency proportional control with proportional bias delivered the optimal control achieved for a given energy expenditure. In comparison, control based upon synaptic inhibitory output from the GPi performed very well in comparison with those of reliability-based control, with considerable further reduction in energy expenditure relative to that of open-loop DBS. The best controller performance was amplitude proportional with derivative control and integral bias, which is full PID control. We demonstrated how optimizing the three components of PID control is feasible in this setting, although the complexity of these optimization functions argues for adaptive methods in implementation. Significance. Our findings point to the potential value of model-based rational design of feedback controllers for Parkinson's disease.

  17. The light cycle controls the hatching rhythm in Bombyx mori via negative feedback loop of the circadian oscillator.

    Science.gov (United States)

    Tao, Hui; Li, Xue; Qiu, Jian-Feng; Liu, Heng-Jiang; Zhang, Da-Yan; Chu, Feng; Sima, Yanghu; Xu, Shi-Qing

    2017-10-01

    Hatching behavior is a key target in silkworm (Bombyx mori) rearing, especially for the control of Lepidoptera pests. According to previous research, hatching rhythms appear to be controlled by a clock mechanism that restricts or "gates" hatching to a particular time. However, the underlying mechanism remains elusive. Under 12-h light:12-h dark photoperiod (LD) conditions, the transcriptional levels of the chitinase5 (Cht5) and hatching enzyme-like (Hel) genes, as well as the enzymatic activities of their gene products, oscillated in time with ambient light cycles, as did the transcriptional levels of the cryptochrome 1, cryptochrome 2, period (per), and timeless genes, which are key components of the negative feedback loop of the circadian rhythm. These changes were related to the expression profile of the ecdysteroid receptor gene and the hatching behavior of B. mori eggs. However, under continuous light or dark conditions, the hatching behavior, the expression levels of Cht5 and Hel, as well as the enzymatic activities of their gene products, were not synchronized unlike under LD conditions. In addition, immunohistochemistry experiments showed that light promoted the translocation of PER from the cytoplasm to the nucleus. In conclusion, LD cycles regulate the hatching rhythm of B. mori via negative feedback loop of the circadian oscillator. © 2017 Wiley Periodicals, Inc.

  18. Transient voltage control of a DFIG-based wind power plant for suppressing overvoltage using a reactive current reduction loop

    Directory of Open Access Journals (Sweden)

    Geon Park

    2016-01-01

    Full Text Available This paper proposes a transient voltage control scheme of a doubly fed induction generator (DFIG-based wind power plant (WPP using a reactive current reduction loop to suppress the overvoltage at a point of interconnection (POI and DFIG terminal after a fault clearance. The change of terminal voltage of a DFIG is monitored at every predefined time period to detect the fault clearance. If the voltage change exceeds a set value, then the reactive current reduction loop reduces the reactive current reference in the DFIG controller using the step function. The reactive current injection of DFIGs in a WPP is rapidly reduced, and a WPP can rapidly suppress the overvoltage at a fault clearance because the reactive current reference is reduced. Using an electromagnetic transients program–released version (EMTP–RV simulator, the performance of the proposed scheme was validated for a model system comprising 20 units of a 5-MW DFIG considering various scenarios, such as fault and wind conditions. Test results show that the proposed scheme enables a WPP to suppress the overvoltage at the POI and DFIG terminal within a short time under grid fault conditions.

  19. Designing Scenarios for Controller-in-the-Loop Air Traffic Simulations

    Science.gov (United States)

    Kupfer, Michael; Mercer, Joey; Cabrall, Chris; Homola, Jeff; Callantine, Todd

    2013-01-01

    Within the Human Factors Division at NASA Ames Research Center the Airspace Operations Laboratory (AOL) is developing advanced automation concepts that help to transform the National Airspace System into NextGen, the Next Generation Air Transportation System. High-fidelity human-in-the-loop (HITL) simulations are used as a means to investigate and develop roles, responsibilities, support tools, and requirements for human operators and automation. This paper describes the traffic scenario design process and strategies as used by AOL researchers. Details are presented on building scenarios for specific simulation objectives using various design strategies. A focus is set on creating scenarios based on recorded real world traffic for terminal-area simulations.

  20. Concentration and length dependence of DNA looping in transcriptional regulation.

    Directory of Open Access Journals (Sweden)

    Lin Han

    2009-05-01

    Full Text Available In many cases, transcriptional regulation involves the binding of transcription factors at sites on the DNA that are not immediately adjacent to the promoter of interest. This action at a distance is often mediated by the formation of DNA loops: Binding at two or more sites on the DNA results in the formation of a loop, which can bring the transcription factor into the immediate neighborhood of the relevant promoter. These processes are important in settings ranging from the historic bacterial examples (bacterial metabolism and the lytic-lysogeny decision in bacteriophage, to the modern concept of gene regulation to regulatory processes central to pattern formation during development of multicellular organisms. Though there have been a variety of insights into the combinatorial aspects of transcriptional control, the mechanism of DNA looping as an agent of combinatorial control in both prokaryotes and eukaryotes remains unclear. We use single-molecule techniques to dissect DNA looping in the lac operon. In particular, we measure the propensity for DNA looping by the Lac repressor as a function of the concentration of repressor protein and as a function of the distance between repressor binding sites. As with earlier single-molecule studies, we find (at least two distinct looped states and demonstrate that the presence of these two states depends both upon the concentration of repressor protein and the distance between the two repressor binding sites. We find that loops form even at interoperator spacings considerably shorter than the DNA persistence length, without the intervention of any other proteins to prebend the DNA. The concentration measurements also permit us to use a simple statistical mechanical model of DNA loop formation to determine the free energy of DNA looping, or equivalently, the for looping.