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Sample records for ac adjustable speed

  1. ANALYSIS OF EFFECTS OF VECTOR CONTROL ON TOTAL CURRENT HARMONIC DISTORTION OF ADJUSTABLE SPEED AC DRIVE

    KARTIK TAMVADA

    2012-04-01

    Full Text Available Adjustable speed drive (ASD is becoming a significant load component for power distribution. It involves the use of an Induction motor (IM. This paper involves modeling and control of an Induction motor andinvestigates its effects on the total current harmonic distortion of the adjustable speed ac drives. The simulation was carried out with the aid of the Simulink toolbox available in Matlab. It is seen that with Vector control the THDi of the drive reduces considerably.

  2. ANALYSIS OF EFFECTS OF VECTOR CONTROL ON TOTAL CURRENT HARMONIC DISTORTION OF ADJUSTABLE SPEED AC DRIVE

    KARTIK TAMVADA; R.KAMESWARA RAO

    2012-01-01

    Adjustable speed drive (ASD) is becoming a significant load component for power distribution. It involves the use of an Induction motor (IM). This paper involves modeling and control of an Induction motor andinvestigates its effects on the total current harmonic distortion of the adjustable speed ac drives. The simulation was carried out with the aid of the Simulink toolbox available in Matlab. It is seen that with Vector control the THDi of the drive reduces considerably.

  3. High-speed AC motors

    Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)

    1997-12-31

    The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.

  4. Speed of adjustment: Evidence from Borsa Istanbul

    Emrah Arioglu

    2014-06-01

    Full Text Available In this study, we investigate the speed of adjustment for leverage ratios of firms listed on Borsa Istanbul, in order to investigate the prediction of the trade-off theory, regarding capital structure rebalancing. For this purpose, we estimate the speed of adjustment by using Generalized Method of Moments system estimation technique. The results of this estimation suggest the speed of adjustment as approximately 29%. This significant speed of adjustment is consistent with the prediction of trade-off theory, which suggests that firms follow target capital structures and when the firms' leverage ratios deviate from these targets; they make financial decisions with the goal of closing the gap between the previous year's leverage and target leverage of the current period.

  5. Adjustable Speed Drives - Future Challenges and Applications

    Blaabjerg, Frede; Thoegersen, Paul

    2004-01-01

    The main trends within Adjustable Drives in industrial and appliance applications for the next decade are discussed based on the newest developments seen on the market and a few historical trends. Different drive configurations are presented and the general demands to adjustable speed drives are...... specified. Further on power architectures and motor types are discussed in a short term and long-term view. Possible drivers of the future development are identified, and the concept of an ?Electronic Motor? is discussed. A number of applications are presented where variable speed is attractive....

  6. Adjustable Speed Drives and Power Quality

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    This paper provides an overview and proposes cost-effective and efficient opportunities in improving power quality in Adjustable Speed Drive (ASD) systems. In particular, an Electronic Inductor (EI) technique has been used in single drives to overcome the existing challenges in conventional...

  7. Speed Control of DC Motor using AC/AC/DC Converter Based on Intelligent Techniques

    Rakan Kh Antar

    2013-05-01

    Full Text Available    This paper describes the application of ac/ac/dc and ac/dc converters to control the speed of a separately excited DC motor. Artificial neural network and PI controller are trained to select the desired values of firing angles for triggering thyristors of the ac/ac/dc and ac/dc bridge converters in order to control the speed of the dc motor at a desired value with constant and different load torques in order to obtain the best speed response. Simulation results show that the rising time for ac/dc and ac/ac/dc converters at 250rpm are reduced about 79% and 89% respectively, while delay time it reduced about 69% and 64% respectively. Therefore, speed response of the dc motor is more efficient for closed loop system compared with open loop also the response of ac/ac/dc converter is better than ac/dc converter.

  8. Output filters for AC adjustable speed drives

    Blaabjerg, Frede; Hanigovszki, Norbert; Landkildehus, Jorn, Jorn

    2007-01-01

    due to bearing currents, acoustic switching noise. Depending on the specific application, the mitigation of some of these effects (or all) might be necessary. The common solution for mitigating the secondary effects at the output of PWM-VSI is the use of output filters [3],[5],[6]. Several types...... of output filters are used and this paper presents an overview of the various output filter solutions typically employed in industrial applications. The paper does not propose any new solutions and it is intended as a guide for practicing engineers and a source of information for researchers....

  9. Speed of Adjustment in Cointegrated Systems

    Fanelli, Luca; Paruolo, Paolo

    2007-01-01

    This paper considers the speed of adjustment to long-run equilibria, in the context of cointegrated Vector Autoregressive Processes (VAR). We discuss the definition of multivariate p-lives for any indicator of predictive ability, concentrating on cumulated interim multipliers which converge to impact factor for increasing forecasting horizon. Interim multipliers are related to autoregressive Granger-causality coefficients, structural or generalized cumulative impulse responses. We discuss the...

  10. Speed Control of DC Motor using AC/AC/DC Converter Based on Intelligent Techniques

    Rakan Kh Antar

    2013-01-01

       This paper describes the application of ac/ac/dc and ac/dc converters to control the speed of a separately excited DC motor. Artificial neural network and PI controller are trained to select the desired values of firing angles for triggering thyristors of the ac/ac/dc and ac/dc bridge converters in order to control the speed of the dc motor at a desired value with constant and different load torques in order to obtain the best speed response. Simulation results show that the rising time fo...

  11. Adjustable speed drives: Applications and R&D needs

    Stefanovic, V.R.

    1995-09-01

    The largest opportunity for the growth of adjustable speed drives (ASDs) during the next 5-6 years is in pump, fan and compressor (PFC) applications where a constant, fixed speed operation is converted to adjustable speed in order to realize energy savings. Inverter supplied induction motors are and will continue to be predominately used in these applications. Over the long term (10-15 years), the greatest ASD growth is expected in large volume consumer applications: first in hybrid electric vehicles (EVs) and in residential heating, ventilation and air-conditioning (HVAC). Both induction and a variety of AC Permanent Magnet motors are expected to be the dominant technology in this new field. The traditional ASD applications in industries which require adjustable speed (such as machine tools, robotics, steel rolling, extruders, paper mill finishing lines, etc.) offer a relatively limited potential for above average ASD growth since most of these applications have already converted to electronic speed control. As a result, ASD growth in this sector will essentially track the growth of the corresponding industries. If realized, both short and long term ASD growth opportunities will result in significant advancements of ASD technology, which will then substantially affect all other, more fragmented, ASD applications. In fact, any single large volume ASD application will serve as a catalyst for improving ASD characteristics in all other ASD applications with the same voltage rating. ASD cost and reliability (defined in the context of application compatibility) are the two most important factors which will determine whether the ASD growth opportunities are realized. Conversely, any technological improvement which carries a cost increase will be restricted to niche applications, at best. Consequently, future R & D efforts should be directed to secure reduction in ASD cost and improvement in ASD reliability. A specific action plan is outlined in this report.

  12. Operating Regions of Adjustable-Speed Units with Doubly Fed Machines

    Schreier, Luděk; Chomát, Miroslav; Bendl, Jiří

    2004-01-01

    Roč. 49, č. 2 (2004), s. 119-136. ISSN 0001-7043 R&D Projects: GA AV ČR IAA2057102 Keywords : AC machines * adjustable-speed systems * doubly fed machine Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  13. Speed of Adjustment to Selected Labour Market and Tax Reforms

    Annabelle Mourougane; Lukas Vogel

    2009-01-01

    This paper examines the length of economic adjustments to selected structural reforms, drawing on simulations with dynamic general equilibrium and macro-economic neo-Keynesian models. Employment adjustment costs appear to have only a limited effect on the pace of adjustment to reforms and the influence of price adjustment costs on output dynamics is found to be marginal. Accommodative monetary policy can speed up the adjustment to a new equilibrium, though to a varying degree in the different...

  14. Research on AC Variable Frequency Speed Regulation System

    Ou Bing-Xian; Li Qing-Zhong; Yan Jun-Xia

    2013-01-01

    In view of shortcomings existing in shear speed control system, shearer AC speed regulating system is designed and studied. The mathematical model of three-phase asynchronous motor in rotating coordinate system is established, and PWM technology of space vector is discussed. Software and hardware of the asynchronous motor vector control variable frequency speed regulating system are designed. The simulation of system based on Matlab is made and the correctness and feasibility of the sys...

  15. Improved speed estimation in sensorless PM brushless AC drives

    Shen, J. X.; Zhu, Z.Q.; Howe, D.

    2002-01-01

    The application of flux-observer-based sensorless control to permanent-magnet brushless AC motor drives is described. Current methods of speed estimation are assessed, both theoretically and experimentally, and an improved method, which combines the best features of methods in which speed is derived from the differential of rotor position and from the ratio of the electromotive force to excitation flux linkage, is proposed. Its performance is verified experimentally.

  16. An AC/AC Direct Power Conversion Topology Having Multiple Power Grid Connections with Adjustable Loading

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

    these fraction power will be a necessary feature on a deregulated energy market. This paper presents a new topology of a power converter based on the Direct Power Conversion concept, which is able to connect to multiple grids and provide complete decoupling between without circulating power between the......Normally, a power converter has one supply port to connect to the power grid and one or multiple output ports to connect to AC loads that require variable voltage and variable frequency. As the trend on the energy market is towards deregulation, new converter topologies are needed to allow...... to minimize the overall energy cost or in case of special applications, to improve the system redundancy. Also, having a generator that can simultaneously feed fractions of its power into multiple grids which are not coupled (different voltage, frequency, displacement angle) and continuously adjust...

  17. Retrofitting adjustable speed drives for large induction motors

    Adjustable speed drives (ASDs) are used in many power plants to control process flow by varying the speed of synchronous and induction motors. In applications where the flow requirements vary significantly, ASDs reduce energy and maintenance requirements when compared with drag valves, dampers or other methods to control flow. Until recently, high horsepower ASDs were not available for induction motors. However, advances in power electronics technology have demonstrated the reliability and cost effectiveness of ASDs for large horsepower induction motors. Emphasis on reducing operation and maintenance costs and increasing the capacity factor of nuclear power plants has led some utilities to consider replacing flow control devices in systems powered by large induction motors with ASDs. ASDs provide a high degree of reliability and significant energy savings in situations where full flow operation is not needed for a substantial part of the time. This paper describes the basic adjustable speed drive technologies available for large induction motor applications, ASD operating experience and retrofitting ASDs to replace the existing GE Boiling Water Reactor recirculation flow control system

  18. IMPROVED PERFORMANCE OF AN ADJUSTABLE SPEED DRIVES DURING VOLTAGE SAG CONDITION

    S.S.DESWAL

    2010-06-01

    Full Text Available Voltage sags normally do not cause equipment damage but can easily disrupt the operation of sensitive loads such as electronic Adjustable Speed Drives (ASD’s. Voltage sags cause a momentary decrease in DC-link voltage triggering an under voltage trip leading to nuisance tripping of adjustable speed drives (ASD’s employed in continuous-process industries which contributes to loss in revenue. A practical ride-through scheme for an adjustable speed drives based on supercapacitor during voltage sag has been presented in this paper. The supercapacitor maintains the ASD dc bus voltage under voltage sag condition. Energy storage module is connected to support the DC-link voltage during power system faults. The performance of ASD’s under normal and power system faults is first simulated in MATLab Simulink and then experimentally verified. The Data AcQuisition boards (DAQ of National Instruments along with LabVIEW software have been used torecord the observed waveforms.

  19. Capacitive iris to adjust coupling factor between waveguide and ACS linac in J-PARC

    The beam energy of the Japan Proton Accelerator Research Complex (J-PARC) linac has been increased from 181 to 400 MeV by installing Annular-ring Coupled Structure (ACS) cavities in the maintenance period of 2013. Some of the ACS cavities require the correction of the coupling factor between waveguide and the cavity. To adjust the coupling factor, a capacitive iris in the rectangular waveguide was designed. And then, the rectangular waveguide with the capacitive iris was manufactured and installed to one of the ACS cavities. The capacitive iris corrected the coupling factor to the designed value and performed well under high-power operation. (author)

  20. Empirical Evidence of Target Leverage, Adjustment Costs and Adjustment Speed of Non-Financial Firms in Selected African Countries

    Oyebola Fatima Etudaiye-Muhtar; Rubi Ahmad

    2015-01-01

    The issue of target leverage for corporate firms in developing countries has received little attention in extant literature, especially countries in Africa. Given the imperfection that exists in African financial markets that may limit firms access to external capital, this study investigates dynamic adjustment towards a target debt ratio. In addition, the study used a dynamic panel data estimation technique to determine adjustment costs and speed of adjustment in non-financial firms in selec...

  1. Online speed control of a brushless AC servomotor based on artificial neural networks

    PARTAL, Sibel; Şenol, İbrahim; BAKAN, Ahmet Faruk

    2011-01-01

    In this paper, an alternative approach to speed estimation of brushless AC servomotors is presented. Speed control is realized in the following steps. First, the servomotor was mathematically modelled; the driver system was designed and speed control of the servomotor was accomplished with feedback. Next, a network structure representing the electrical and mechanical properties of the servomotor was built via Artificial Neural Network (ANN) and trained with the results of the first ...

  2. AC-DC integrated load flow calculation for variable speed offshore wind farms

    Zhao, Menghua; Chen, Zhe; Blaabjerg, Frede

    2005-01-01

    This paper proposes a sequential AC-DC integrated load flow algorithm for variable speed offshore wind farms. In this algorithm, the variable frequency and the control strategy of variable speed wind turbine systems are considered. In addition, the losses of wind turbine systems and the losses of...... converters are also integrated into the load flow algorithm. As a general algorithm, it can be applied to different types of wind farm configurations, and the load flow is related to the wind speed....

  3. FLC based adjustable speed drives for power quality enhancement

    Sukumar Darly

    2010-01-01

    Full Text Available This study describes a new approach based on fuzzy algorithm to suppress the current harmonic contents in the output of an inverter. Inverter system using fuzzy controllers provide ride-through capability during voltage sags, reduces harmonics, improves power factor and high reliability, less electromagnetic interference noise, low common mode noise and extends output voltage range. A feasible test is implemented by building a model of three-phase impedance source inverter, which is designed and controlled on the basis of proposed considerations. It is verified from the practical point of view that these new approaches are more effective and acceptable to minimize the harmonic distortion and improves the quality of power. Due to the complex algorithm, their realization often calls for a compromise between cost and performance. The proposed optimizing strategies may be applied in variable-frequency dc-ac inverters, UPSs, and ac drives.

  4. From Periphery to Core: Economic Adjustments to High Speed Rail

    Ahlfeldt, Gabriel M.; Feddersen, Arne

    2010-01-01

    This paper presents evidence that high speed rail systems, by bringing economic agents closer together, sustainably promote economic activity within regions that enjoy an increase in accessibility. Our results on the one hand confirm expectations that have led to huge public investments into high speed rail all over the world. On the other hand, they confirm theoretical predictions arising from a consolidate body of (New) Economic Geography literature taking a positive, man-made and reproduci...

  5. Sensorless control of AC machines for low and zero speed operation without additional test signal injection

    Raute, Reiko

    2009-01-01

    This work considers the sensorless control of AC machines for the low and zero speed operation range. Two novel techniques have been developed that use the inherit nature of the inverter PWM to estimate the rotor position of the machine. The inherent back EMF and the saliency of AC machines can be utilized to identify the rotor/flux position. The zero vector current derivative (ZVCD) technique for permanent magnet synchronous machines (PMSM) utilizes both of these effects. No additional ...

  6. Fuzzy gain auto-tuning implementation for ac speed servo and mechanical motion load system

    In this paper, in order to suppress the mechanical resonance and anti- resonance in the DC brushless motor-based AC speed servo system with two-mass mechanical motion load, the load speed observer with load disturbance estimating function, which is suitable for the load speed feedback compensation, is proposed. The auto-tuning control implementation based on fuzzy reasoning with the observer- based load speed feedback compensation is compared with conventional PI compensation scheme. The experimental results prove considerable reduction in mechanical vibration and show improved response characteristics of mechanical motion load system. (author)

  7. Minimize Adverse Motor and Adjustable Speed Drive Interactions - Motor Tip Sheet #15

    None

    2008-07-01

    Electronic adjustable speed drives (ASDs) are an extremely efficient and valuable asset to motor systems. They allow precise process control and provide energy savings within systems that do not need to continuously operate at full output.

  8. Improvement of power system stability of an adjustable-speed pumped-storage generator/motor. Denryoku keito ni okeru kahensoku yosui hatsuden dendoki no keito anteido kojo ni kansuru kenkyu

    Michigami, T. (Tokyo Electric Power Co., Inc. (Japan)); Koyanagi, K. (Toshiba Corp., Tokyo (Japan))

    1994-02-20

    Recently, adjustable-speed pumped-storage generator/motor (adjustable-speed machine) is applied to power system as AFC adjusting force. This adjustable-speed machine has no problem on its stability and AC excitation control is carried out by the cycloconverter with speedy response since its being different from the conventional fixed-speed synchronous machine that the rotor speed becomes to adjustable. In this paper, aiming at the improvement of power system stability by using said adjustable-speed machine, the basic consideration on the rotor speed and reactive power control by AC excitation of the adjustable-speed machine; theoretical examination on the analysis model for analysing the system stability; analysis simulation results using two machine-pair infinite system for obtaining the basic properties of the improvement of power system stability; verification results on the effectiveness of improvement of power system stability as well as analysis model by simulative power transmission test are described. Further, the analysis simulation results on the effectiveness of improvement of power system stability by the models with the scale of practical system are reported. 11 refs., 15 figs., 9 tabs.

  9. Hybrid pressure control concept for a speed variable AC motor pump in aerospace application

    Engelhardt, Joerg; Greissner, Carsten

    2002-01-01

    This paper describes a new pressure control strategy for AC motor driven pumps in aircraft application. Both, swash plate position and pump speed are used for controlling system pressure in a hybrid approach. The requirements for the pressure control loop and the design methods for the hybrid control circuits with a load observer are introduced. The new control concept has been implemented into an experimental set-up. The validation and evaluation of simulation results on the test rig are d...

  10. Maximum Efficiency Point Tracking for Adjustable-Speed Small Hydro Power Plant

    BORGHETTI Alberto; Di Silvestro, Mauro; Naldi, Gleb; Paolone, Mario; Alberti, Massimo

    2008-01-01

    The paper presents the general scheme and the relevant implementation of a Maximum Efficiency Point Tracking (MEPT) system for a Small Hydro Power (SHP) plant equipped with a variable-speed generator. This last consists of a Doubly Fed Induction Generator (DFIG) and a power electronic converter that independently controls both the rotor speed and the generator power factor. The MEPT is designed to be used with a propeller turbine with adjustable runner blade angle and it is coupled with the h...

  11. Adjustable Speed Drive Project for Teaching a Servo Systems Course Laboratory

    Rodriguez-Resendiz, J.; Herrera-Ruiz, G.; Rivas-Araiza, E. A.

    2011-01-01

    This paper describes an adjustable speed drive for a three-phase motor, which has been implemented as a design for a servo system laboratory course in an engineering curriculum. The platform is controlled and analyzed in a LabVIEW environment and run on a PC. Theory is introduced in order to show the sensorless algorithms. These are computed by…

  12. LC Filter Design for Wide Band Gap Device Based Adjustable Speed Drives

    Vadstrup, Casper; Wang, Xiongfei; Blaabjerg, Frede

    This paper presents a simple design procedure for LC filters used in wide band gap device based adjustable speed drives. Wide band gap devices offer fast turn-on and turn-off times, thus producing high dV/dt into the motor terminals. The high dV/dt can be harmful for the motor windings and bearings...

  13. Adjustable speed operation of a hydropower plant associated to an irrigation reservoir

    This paper deals with the issue of adjustable speed operation (ASO) of hydropower plants. The main idea of this technique is to allow the turbine speed to change in accordance with hydraulic conditions, thus improving the overall unit efficiency. General technical aspects of ASO are further discussed with special emphasis on the energy and operational benefits that may potentially result from its application. In order to assess these benefits, annual operation of a hydropower plant associated to an irrigation reservoir has been simulated under different scenarios, with both adjustable and fixed speed. Turbine operating range proved to be wider with ASO. In addition, simulation results confirm that considerable energy gains are expected to be obtained

  14. Intraday Speed of Adjustment and the Realized Variance in the Indonesia Stock Exchange

    Zaafri A Husodo

    2009-01-01

    Full Text Available We examine the intraday trading and price dynamics for frequently traded stocks at the Indonesian Stock Exchange. Using trade price, time series generated at one, two, three, five, ten, fifteen, thirty and sixty-minute intervals, we estimate the speed of adjustment and the corresponding realized variance of these series. The objective of the estimation is to infer the noise impact to the deviation of observed prices from their fundamental value. The result from the speed of adjustment estimate is consistent with the realized variance estimator. Both conclude that the 50 most frequently traded stocks in the Indonesia Stock Exchange adjust to new information within 30 minutes. At the interval, the coefficient of the speed of price adjustment is insignificantly different from zero implying negligible noise impact to the observed price. Concurrently, the realized variance starts to stabilize at 30-minute interval purporting fading impact of noise to the realized variance estimate. The evidence justifies the use of realized variance at various intervals as a reliable indicator of price discovery rate in the Indonesia Stock Exchange.

  15. Adjustable Speed Drives in the Next Decade. Future Steps in Industry and Academia

    Thøgersen, Paul; Blaabjerg, Frede

    2004-01-01

    The main trends for the next decade within the multi-disciplinarian field of adjustable speed drives are discussed, and a number of topics are especially addressed in this paper. The topics include market development over the last decade, historical development in power converter volume and weigh......, future drive demands, power converter architecture, interfacing to the grid, motor types, and control principles. Furthermore, some of the possibilities and trends related to decentral ?intelligence? and Internet connection are discussed.......The main trends for the next decade within the multi-disciplinarian field of adjustable speed drives are discussed, and a number of topics are especially addressed in this paper. The topics include market development over the last decade, historical development in power converter volume and weight...

  16. Speed-accuracy trade-off behavior: Response caution adjustment or mixing task strategies?

    van Maanen

    2015-01-01

    The speed-accuracy trade-off (SAT) effect refers to the behavioral trade-off between fast yet error-prone responses and accurate but slow responses. Multiple theories on the cognitive mechanisms behind SAT exist. One theory assumes that SAT is a consequence of strategically adjusting the amount of evidence required for overt behaviors, such as perceptual choices. Another theory hypothesizes that SAT is the consequence of mixing different task strategies. In this paper these theories are disam...

  17. Adjustable-Speed Single-Phase IM Drive with Reduced Number of Switches

    Chomát, Miroslav; Lipo, T. A.

    Chicago : IEEE Industry Applications Society IAS, 2001, s. 1-6. ISBN 0-7803-7114-3. [IEEE Industry Applications Conference - Annual Meeting /36./. Chicago (US), 30.09.2001-04.10.2001] R&D Projects: GA AV ČR IAB2057903 Grant ostatní: NSFA(US) 9820434 Keywords : adjustable-speed drive * single-phase induction machine Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  18. Adjustable-Speed Drive with Single-Phase Induction Machine for HVAC Applications

    Chomát, Miroslav; Lipo, T. A.

    Vancouver : University of British Columbia, 2001, s. 1-6. ISBN 0-7803-7069-4. [Power Electronics Specialists Conference PESC 2001 /32./. Vancouver (CA), 17.06.2001-22.06.2001] R&D Projects: GA MŠk ME 332 Grant ostatní: NSFA(US) 9820434 Keywords : adjustable-speed drive * single-phase induction machine Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  19. Comparison of the Accuracy and Speed of Transient Mobile A/C System Simulation Models: Preprint

    Kiss, T.; Lustbader, J.

    2014-03-01

    The operation of air conditioning (A/C) systems is a significant contributor to the total amount of fuel used by light- and heavy-duty vehicles. Therefore, continued improvement of the efficiency of these mobile A/C systems is important. Numerical simulation has been used to reduce the system development time and to improve the electronic controls, but numerical models that include highly detailed physics run slower than desired for carrying out vehicle-focused drive cycle-based system optimization. Therefore, faster models are needed even if some accuracy is sacrificed. In this study, a validated model with highly detailed physics, the 'Fully-Detailed' model, and two models with different levels of simplification, the 'Quasi-Transient' and the 'Mapped- Component' models, are compared. The Quasi-Transient model applies some simplifications compared to the Fully-Detailed model to allow faster model execution speeds. The Mapped-Component model is similar to the Quasi-Transient model except instead of detailed flow and heat transfer calculations in the heat exchangers, it uses lookup tables created with the Quasi-Transient model. All three models are set up to represent the same physical A/C system and the same electronic controls. Speed and results of the three model versions are compared for steady state and transient operation. Steady state simulated data are also compared to measured data. The results show that the Quasi-Transient and Mapped-Component models ran much faster than the Fully-Detailed model, on the order of 10- and 100-fold, respectively. They also adequately approach the results of the Fully-Detailed model for steady-state operation, and for drive cycle-based efficiency predictions

  20. Comparison between AC and MFDC resistance spot welding by using high speed filming

    S.C.A. Alfaro

    2007-09-01

    Full Text Available Purpose: In this work it will be carried through the filming of the formation and growth of the nugget in resistance spot welding executed in AC and MF. A comparison for same times in both the processes will be carried through to verify which of the used processes offers better conditions, control and results as well as will help for one better understanding of the process aiming at the otimização.Design/methodology/approach: Two different spot welding machine (AC and MF-DC had been used, and a digital high-speed camera. The weld points had been carried through in 3 galvanized steel different plate configurations. The electrodes had been truncated to obtain one better visualization for the weld nugget formation. The comparison of the formation and development between the weld point of each process (AC and MF is shown in 7 pictures in the same values of time.Findings: For currents below 2 kA, no nugget was observed. and the formation of same after 10º cycle for bigger current of 3 kA. The MF-DC welding offers the possibility of obtaining nuggets more uniforms within shorter times (depending on the plate configuration.Research limitations/implications: In this work the AC machine is limited by the values of current of welding and pressure of the electrodes: (2 - 6 kA e (87 - 261 kgf respectively. Other materials: aluminum, stainless steel or material exactly dissimilar could be used following the line of this research. Bigger currents levels can also be used.Originality/value: The idea to compare resulted for the same process of welding under different conditions (equipment, materials and or parameters makes possible the choice of these better conditions used to the otimização of the process.

  1. A Study of Hydrogen Generation with Doubly-Fed Adjustable Speed Wind Generator

    Kinoshita, Hirotaka; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji; Sugimasa, Masatoshi; Komura, Akiyoshi; Futami, Motoo; Ichinose, Masaya; Ide, Kazumasa

    This paper presents a combination system of wind power generator and hydrogen generator. In the proposed system, Doubly-Fed Synchronous Generator (DFSG) is used as an adjustable speed wind generator, and an electrolyzer is connected to its terminal for hydrogen generation, which is controlled by power electronic converters. Output power from the wind generator is smoothed and supplied to the power system as well as to the electrolyzer to generate hydrogen under a cooperative control of the wind generator and the electrolyzer. The performance of the proposed system is investigated by simulation analyses, in which simulations are performed by using PSCAD/EMTDC.

  2. A high speed camera with auto adjustable ROI for product's outline dimension measurement

    Wang, Qian; Wei, Ping; Ke, Jun; Gao, Jingjing

    2014-11-01

    Currently most domestic factories still manually detect machine arbors to decide if they meet industry standards. This method is costly, low efficient, and easy to misjudge the qualified arbors or miss the unqualified ones, thus seriously affects factories' efficiency and credibility. In this paper, we design a specific high-speed camera system with auto adjustable ROI for machine arbor's outline dimension measurement. The entire system includes an illumination part, a camera part, a mechanic structure part and a signal processing part based on FPGA. The system will help factories to realize automatic arbor measurement, and improve their efficiency and reduce their cost.

  3. Combinatorial Optimization Method for Operation of Pumping Station with Adjustable Blade and Variable Speed Based on Experimental Optimization of Subsystem

    Yi Gong; Jilin Cheng

    2014-01-01

    A decomposition-dynamic programming aggregation method based on experimental optimization for subsystem was proposed to solve mathematical model of optimal operation for single pumping station with adjustable blade and variable speed. Taking minimal daily electric cost as objective function and water quantity pumped by units as coordinated variable, this model was decomposed into several submodels of daily optimal operation with adjustable blade and variable speed for single pump unit which w...

  4. Investigation of Electrode Erosion Mechanism of Multi-Phase AC Arc by High-Speed Video Camera

    A multi-phase AC arc has been applied to the glass melting technology. However, the electrode erosion is one of the most considerable issues to be solved. In order to investigate the erosion mechanism of the multi-phase AC arc, the combination of the high-speed video camera and the band-pass filters was introduced to measure the electrode temperature. Results indicated the tip temperature of the electrode surface in the 12-phase arc was lower than that in the 2-phase arc, while erosion rate in 12-phase arc was higher than that in the 2-phase arc. Furthermore, the dynamic behaviour of the vapours in the arc was investigated by using the same high-speed camera system. The tungsten electrode mainly evaporates at the anodic period during AC cycle. The oxygen concentration in the arc increases with larger number of the phases, resulting in the higher erosion rate in the 12-phase arc.

  5. Passive wide spectrum harmonic filter for adjustable speed drives in oil and gas industry

    Al Jaafari, Khaled Ali

    Non-linear loads such as variable speed drives constitute the bulky load of oil and gas industry power systems. They are widely used in driving induction and permanent magnet motors for variable speed applications. That is because variable speed drives provide high static and dynamic performance. Moreover, they are known of their high energy efficiency and high motion quality, and high starting torque. However, these non-linear loads are main sources of current and voltage harmonics and lower the quality of electric power system. In fact, it is the six-pulse and twelve-pulse diode and thyristor rectifiers that spoil the AC power line with the dominant harmonics (5th, 7th, 11th). They provide DC voltage to the inverter of the variable speed drives. Typical problems that arise from these harmonics are Harmonic resonances', harmonic losses, interference with electronic equipment, and line voltage distortion at the Point of Common Coupling (PCC). Thus, it is necessary to find efficient, reliable, and economical harmonic filters. The passive filters have definite advantage over active filters in terms of components count, cost and reliability. Reliability and maintenance is a serious issue in drilling rigs which are located in offshore and onshore with extreme operating conditions. Passive filters are tuned to eliminate a certain frequency and therefore there is a need to equip the system with more than one passive filter to eliminate all unwanted frequencies. An alternative solution is Wide Spectrum Harmonic passive filter. The wide spectrum harmonic filters are becoming increasingly popular in these applications and found to overcome some of the limitations of conventional tuned passive filter. The most important feature of wide spectrum harmonic passive filters is that only one capacitor is required to filter a wide range of harmonics. Wide spectrum filter is essentially a low-pass filter for the harmonic at fundamental frequency. It can also be considered as a

  6. Commutation effect of Adjustable Speed Drives due to installation of active harmonic filters

    Asiminoaei, Lucian; Kalaschnikow, Sergej; Hansen, Steffan;

    2011-01-01

    The success of designing an industrial installation with Active Filters depends on how precise the load profile of the application is known, because this determines the amount of harmonic currents to be compensated. However, once the Active Filter is added to the installation, the harmonic currents...... may increase due to changes in the commutation behavior of diode rectifier converters. The change of natural commutation determines higher harmonics currents of the diode rectifiers and therefore higher harmonic loading of the Active Filter in the installation. This paper presents a method to estimate...... the commutation behavior of Adjustable Speed Drives when their harmonic currents are compensated by a Shunt Active Filter. The method is formulated as an analytical computation algorithm verified by simulations. Further on the method is implemented in a Harmonic Calculation Toolbox which facilitates...

  7. A New Low-Cost Hybrid Switched Reluctance Motor for Adjustable-Speed Pump Applications

    Lu, Kaiyuan; Rasmussen, Peter Omand; Watkins, Steve;

    2011-01-01

    This paper presents a new low-cost hybrid switched reluctance (HSR) motor intended for use in adjustable-speed pump drive systems. The motor is a single-phase motor, driven by a unipolar converter, which uses both the reluctance torque and the permanent magnet interaction torque. Compared...... with conventional single-phase switched reluctance motors, it has an increased torque density. The cogging torque is beneficially used in this motor for reducing the torque ripple. It is demonstrated that such a motor drive system can be a suitable candidate to advantageously compete with the existing motor drive...... systems for low-cost applications. Finite-element models are used to analyze and predict the motor's performance. The proposed motor drive system has been fabricated, and its performance has been tested in the laboratory. These experimental results are also presented....

  8. Feedforward Synchronised PWM for Adjustable Speed AC Drives with Different Control Modes

    Oleschuk, Valentin; Blaabjerg, Frede; Jensen, Flemming Buus

    2002-01-01

    This paper presents a novel method of direct synchronised pulswidth modulation (PWM) for three-phase voltage source inverters, feeding induction motors with different control regimes. It is based on the universal algorithm with either simplified algebraic or accurate trigonometric control functions......, with vector approached for determination of the pulse patterns, with vector approach for determination of the pulse patterns. Different control modes of the drive system with synchronised PWM, including standard scalar V/F control, and also V2/F = constant and V/F2 = constant control regimes, have been...... analysed in the paper. Simulations give the behaviour of the PWM techniques proposed. Both continuous and discontinuous schemes of synchronised PWM, applied for the corresponding control regime, have been analysed and compared....

  9. An EMC Evaluation of the Use of Unshielded Motor Cables in AC Adjustable Speed Drive Applications

    Hanigovszki, Norbert; Poulsen, J.; Spiazzi, G.;

    2004-01-01

    -phase applications the occurrence of common-mode voltage is inherent due to asymmetrical output pulses. As a result, for electromagnetic compatibility (EMC) reasons, in most applications shielded cables are used between the inverter and the motor, implying high installation costs. The present paper discusses the use...... of cheaper, unshielded cables. A new method for measuring electromagnetic interference (EMI) from unshielded cables is proposed and measurement results are presented. The level of EMI is evaluated in different situations: without an output filter, with a classical LC output filter and with an...

  10. 400-MW adjustable-speed pumped-storage hydraulic power plant

    Kita, E. [Kansai Electric Power Co. Inc., Osaka (Japan); Bando, A.; Kuwabara, T. [Hitachi, Ltd., Tokyo (Japan)

    1995-02-01

    The performance of the 400 MW adjustable-speed pumped-storage hydraulic power plant of Okawachi Power Station, Kansai Electric Power Co., Inc., Japan is outlined. The plant adopts a cycloconverter for an exciter, and uses selectively one of three real power control modes such as fixed-frequency excitation, synchronous speed control and slip-phase control according to internal phase angles. The plant also adopts the operation mode giving priority to quick response to output commands, and the stator frequency detecting mode giving priority to response to power systems. The plant maintains an AFC capacity of {plus_minus}80 MW during pumping operation, and satisfies the intended performance requirements in both generating and pumping modes. The overcurrent and overvoltage protection systems of which functions were ascertained to be effective through power system tests, are used to eliminate side effects due to use of the cycloconverter for an exciter. The specific transient phenomenon analysis system is also used for supporting maintenance works. 5 refs., 12 figs., 2 tabs.

  11. Dynamic melting and impurity particle tracking in continuously adjustable AC magnetic field

    Bojarevics, V.; Pericleous, K.

    2016-07-01

    The analysis of semi-levitation melting is extended to account for the presence of particles (impurities, broken metal dendrite agglomerates, bubbles) during the full melting cycle simulated numerically using the pseudo-spectral schemes. The AC coil is dynamically moving with the melt front progress, while the generated Joule heat serves to enhance the melting rate. The electromagnetic force is decomposed into the time average and the oscillating parts. The time average effects on the particle transport are investigated previously using approximations derived for a locally uniform magnetic field. This paper presents expressions for the skin-layer type of the AC force containing also the pulsating part which contributes to the particle drag by the ‘history’ and ‘added mass’ contributions. The intense turbulence in the bulk of molten metal additionally contributes to the particle dispersion. The paper attempts to demonstrate the importance of each of the mentioned effects onto the particle transport during the melting until the final pouring stage. The method could be extended to similar AC field controlled melting/solidification processes.

  12. Evaluation of the Ride-Through Capability of an Active-Front-End Adjustable Speed Drive under Real Grid Conditions

    Liserre, Marco; Klumpner, Christian; Blaabjerg, Frede;

    2004-01-01

    Better quality of the input currents, unity power factor and regenerative capability are not the only benefits of equipping an Adjustable Speed Drive (ASD) with an active front-end-stage. Controlling the power inflow may enable also the reduction of the dc-link energy storage, which will then lead...

  13. Analysis of cutting-edge techniques in the high voltage and high power adjustable speed drive systems

    2009-01-01

    The high voltage and high power adjustable speed drive (ASD) system is one of the most attractive fields in power electronics, and it is also a very crucial technique for energy saving and emission reduction. This paper discussed and analyzed the main cutting-edge knowledge and issues in the process of exploiting the high voltage and high power ASD system.

  14. The Single-Phase AC-DC Conversion Circuit with Power Factor Adjustable%功率因数可调单相AC-DC变换电路∗

    杨力; 张师斌; 赵宁

    2015-01-01

    This design is a single-phase AC-DC conversion circuit with power factor adjustable based on UCC28019A. MSP430 is selected as the control core. We adopt the high precision 24-bitΣ-ΔADC to measure the input voltage RMS,the input current RMS,the active power RMS,the power factor and some other parameters. The power-factor correction is accomplished by UCC28019A. By controlling the digital phase shift circuit to shift the phase of the current feedback signal,the power factor can be set in the range of 0.8 to 1.0. By detecting the output current and voltage,the circuit has the function of 2.5A overcurrent protection and 36V regulated output.%基于UCC28019A设计的功率因数可调单相AC-DC变换电路。 MSP430单片机作为其控制核心,使用高精度24 bitΣ-Δ型ADC采样,可完成对输入电压有效值、输入电流有效值、有功功率有效值、功率因数等参数的测量。由UCC28019A完成功率因数的校正,通过控制数字移相电路对外围电流反馈信号移相,实现功率因数在0.8~1.0范围内的调整。本设计还可通过对输出电流和电压的监测,实现2.5 A过流保护和36 V稳压输出的功能。

  15. IEEE 802.11ac: Next Generation High Speed Wireless LAN Technology

    Ms. Laxmi Chaudhary

    2015-06-01

    Full Text Available This paper gives an overview of the IEEE 802.11ac which has been proposed to enhance the throughput of IEEE 802.11n beyond Gigabit-per second rates. 802.11ac adds multi-user access techniques in the form of downlink multi-user (DL MU multiple input multiple output (MIMOand 80 and 160 MHz channels in the 5 GHz band for applications such as multiple simultaneous video streams throughout the home. For this the IEEE 802.11ac task group is working on the amendment that has goal of reaching maximum network throughput of atleast 1 Gbps on bands below 6GHz & continuing to support the legacy of 5GHz 802.11 devices. In this paper we describe the 802.11ac key features, channelization, MAC modifications and modulation enhancements and its various applications in wireless technology.

  16. Establishing force and speed training targets for lumbar spine high-velocity, low-amplitude chiropractic adjustments*

    Owens, Edward F.; Hosek, Ronald S.; Sullivan, Stephanie G.B.; Russell, Brent S.; Mullin, Linda E.; Dever, Lydia L.

    2016-01-01

    Objective: We developed an adjusting bench with a force plate supporting the lumbar portion to measure loads transmitted during lumbar manual adjustment. It will be used to provide force-feedback to enhance student learning in technique labs. The study goal is to define the learning target loads and speeds, with instructors as expert models. Methods: A total of 11 faculty members experienced in teaching Gonstead technique methods performed 81 simulated adjustments on a mannequin on the force plate. Adjustments were along 9 lumbopelvic “listings” at 3 load levels: light, normal, and heavy. We analyzed the thrusts to find preload, peak load, duration, and thrust rate. Results: Analysis of 891 thrusts showed wide variations between doctors. Peak loads ranged from 100 to 1400 N. All doctors showed clear distinctions between peak load levels, but there was overlap between high and low loads. Thrust rates were more uniform across doctors, averaging 3 N/ms. Conclusion: These faculty members delivered a range of thrusts, not unlike those seen in the literature for high velocity, low amplitude manipulation. We have established at least minimum force and speed targets for student performance, but more work must be done to create a normative adjustment to guide refinement of student learning. PMID:26600272

  17. Adjustable-Speed Single-Phase IM Drive with Reduced Number of Switches

    Chomát, Miroslav; Lipo, T. A.

    2003-01-01

    Roč. 39, č. 3 (2003), s. 819-825. ISSN 0093-9994 R&D Projects: GA ČR GA102/02/0554 Grant ostatní: National Science Foundation(US) GA9820434 Institutional research plan: CEZ:AV0Z2057903 Keywords : AC motor drives * converters * induction motor drives Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.783, year: 2003

  18. Shunt active filter algorithms for a three phase system fed to adjustable speed drive

    Sujatha.CH; Sravanthi.Kusam; Dr. K.Chandra shek

    2011-01-01

    This paper presents the simulation of Shunt Active Power filter by using two different control schemes, Indirect current control technique and Synchronous detection technique by using ANN. These two control techniques are working under both balanced and unbalanced three phase voltage source conditions and it is feeding to aadjustable speed drive the torque speed characteristics of a motor is presented. Indirect current control technique is implemented under dynamic load condition and load bal...

  19. Dynamic Modeling of Adjustable-Speed Pumped Storage Hydropower Plant: Preprint

    Muljadi, E.; Singh, M.; Gevorgian, V.; Mohanpurkar, M.; Havsapian, R.; Koritarov, V.

    2015-04-06

    Hydropower is the largest producer of renewable energy in the U.S. More than 60% of the total renewable generation comes from hydropower. There is also approximately 22 GW of pumped storage hydropower (PSH). Conventional PSH uses a synchronous generator, and thus the rotational speed is constant at synchronous speed. This work details a hydrodynamic model and generator/power converter dynamic model. The optimization of the hydrodynamic model is executed by the hydro-turbine controller, and the electrical output real/reactive power is controlled by the power converter. All essential controllers to perform grid-interface functions and provide ancillary services are included in the model.

  20. High-Speed Visualization of Evaporation Phenomena from Tungsten Based Electrode in Multi-Phase AC Arc

    Tanaka, Manabu; Hashizume, Taro; Imatsuji, Tomoyuki; Nawata, Yushi; Watanabe, Takayuki

    2015-09-01

    A multi-phase AC arc has been developed for applications in various fields of engineering because it possesses unique advantages such as high energy efficiency. However, understanding of fundamental phenomena in the multi-phase AC arc is still insufficient for practical use. Purpose of this study is to investigate electrode erosion mechanism by high-speed visualization of the electrode metal vapor in the arc. Results indicated that the electrode mainly evaporated at anodic period, leading to the arc constriction. Moreover, evaporation of W electrode with 2wt% La2O3 at the anodic period was much higher than that with 2wt% ThO2. This can be explained by different properties of these oxide additives. Evaporation of the oxide additive resulted in the arc constriction, which accelerated the evaporation of W electrode. Therefore, addition of La2O3 with lower melting and boiling point than ThO2 lead to stronger arc constriction, resulting in severer evaporation of W electrode.

  1. A Novel Adjustment Method for Shearer Traction Speed through Integration of T-S Cloud Inference Network and Improved PSO

    Lei Si

    2014-01-01

    Full Text Available In order to efficiently and accurately adjust the shearer traction speed, a novel approach based on Takagi-Sugeno (T-S cloud inference network (CIN and improved particle swarm optimization (IPSO is proposed. The T-S CIN is built through the combination of cloud model and T-S fuzzy neural network. Moreover, the IPSO algorithm employs parameter automation adjustment strategy and velocity resetting to significantly improve the performance of basic PSO algorithm in global search and fine-tuning of the solutions, and the flowchart of proposed approach is designed. Furthermore, some simulation examples are carried out and comparison results indicate that the proposed method is feasible, efficient, and is outperforming others. Finally, an industrial application example of coal mining face is demonstrated to specify the effect of proposed system.

  2. Adjusting for car occupant injury liability in relation to age, speed limit, and gender-specific driver crash involvement risk.

    Keall, Michael; Frith, William

    2004-12-01

    It is well established that older drivers' fragility is an important factor associated with higher levels of fatal crash involvement for older drivers. There has been less research on age-related fragility with respect to the sort of minor injuries that are more common in injury crashes. This study estimates a quantity that is related to injury fragility: the probability that a driver or a passenger of that driver will be injured in crashes involving two cars. The effects of other factors apart from drivers' fragility are included in this measure, including the fragility of the passengers, the crashworthiness of cars driven, seatbelt use by the occupants, and characteristics of crashes (including configuration and impact speed). The car occupant injury liability estimates appropriately includes these factors to adjust risk curves by age, gender, and speed limit accounting for overrepresentation in crashes associated with fragility and these other factors. PMID:15545071

  3. A Review of Electronic Inductor Technique for Power Factor Correction in Three-Phase Adjustable Speed Drives

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    Electronic Inductor (EI) techniques are promising approaches for improving the grid-side current quality, and they are suitable for motor drive applications. In this paper, different EI topologies are investigated from the efficiency perspective, including the effect of employing Silicon Carbide...... (SiC) power devices. Moreover, the influence of partial loading on component sizing in Adjustable Speed Drives (ASDs) is studied. Finally the analytical loss modelling of power switches is utilized for efficiency measurement. The theoretical analyses are verified by experimental benchmarking in an ASD...

  4. Free-standing few-layered graphene oxide films: selective, steady and lasting permeation of organic molecules with adjustable speeds

    Huang, Tao; An, Qi; Luan, Xinglong; Zhang, Qian; Zhang, Yihe

    2016-01-01

    A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with adjustable and controllable speeds. The steady delivery of the small molecule lasted up to 9 days. Other functionalities, such as graphene-enhanced Raman spectra and electrochemical properties that could also be integrated or employed in delivery systems, were also studied for our films. We expect the special molecular delivery properties of our films to lead to new possibilities in drug/fertilizer delivery and environmental microbiological control applications.A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with

  5. Modulation of Premotor and Primary Motor Cortical Activity during Volitional Adjustments of Speed-Accuracy Trade-Offs.

    Thura, David; Cisek, Paul

    2016-01-20

    Recent work suggests that while animals decide between reaching actions, neurons in dorsal premotor (PMd) and primary motor (M1) cortex reflect a dynamic competition between motor plans and determine when commitment to a choice is made. This competition is biased by at least two sources of information: the changing sensory evidence for one choice versus another, and an urgency signal that grows over time. Here, we test the hypothesis that the urgency signal adjusts the trade-off between speed and accuracy during both decision-making and movement execution. Two monkeys performed a reaching decision task in which sensory evidence continuously evolves over the course of each trial. In different blocks, task timing parameters encouraged monkeys to voluntarily adapt their behavior to be either hasty or conservative. Consistent with our hypothesis, during the deliberation process the baseline and gain of neural activity in decision-related PMd (29%) and M1 cells (45%) was higher when monkeys applied a hasty policy than when they behaved conservatively, but at the time of commitment the population activity was similar across blocks. Other cells (30% in PMd, 30% in M1) showed activity that increased or decreased with elapsing time until the moment of commitment. Movement-related neurons were also more active after longer decisions, as if they were influenced by the same urgency signal controlling the gain of decision-related activity. Together, these results suggest that the arm motor system receives an urgency/vigor signal that adjusts the speed-accuracy trade-off for decision-making and movement execution. Significance statement: This work addresses the neural mechanisms that control the speed-accuracy trade-off in both decisions and movements, in the kinds of dynamic situations that are typical of natural animal behavior. We found that many "decision-related" premotor and motor neurons are modulated in a time-dependent manner compatible with an "urgency" signal that

  6. Limitation of Adjustable-Speed Drive Operation by Unbalanced Voltage Supply

    Chomát, Miroslav; Schreier, Luděk; Bendl, Jiří

    Piscataway : IEEE, 2008, s. 1-6. ISBN 978-1-4244-1736-0. [International Conference on Electrical Machines - ICEM 2008 /18./. Vilamoura (PT), 06.09.2008-09.09.2008] R&D Projects: GA ČR GA102/06/0215 Institutional research plan: CEZ:AV0Z20570509 Keywords : unbalanced voltage supply * DC-link voltage pulsations * variable-speed drive Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering www.apdee.org

  7. New possibilities with new technology: the Adjustable Speed Hydro (ASH) generator

    Generators with variable rotational speed can be the solution for the Norwegian power system. The technology is available and is already used abroad. As with all projects, investing in ASH must be based on economic profitability, where all advantages and disadvantages are considered, and on thorough techno-economic analyses. The article describes the fundamental principles of the ASH, its advantages, and discusses its possible installation in already existing power stations

  8. Stabilization of multi-machine power system by coordinated excitation control of multiple adjustable-speed generator/motors; Fukusu kahensoku hatsuden dendoki no reiji den`atsu kyocho seigyo ni yoru taki keito anteika

    Tatematsu, M.; Yokoyama, A. [The University of Tokyo, Tokyo (Japan)

    1996-01-20

    Since an adjustable-speed generator/motor (ASGM) is excited by AC voltage fed by a quick-response cycloconverter, a rotating speed of the rotor can be changed continuously. The ASGMs installed at some pumping-up power stations are now operated effectively for automatic frequency control under the lightly loaded condition at night by changing the pumping-up power due to the rotating speed change. It is expected, on the other hand, that under the generating condition in the daytime the ASGM will be used for enhancement of transient stability because it can generate or absorb active and reactive power independently of each other by AC excitation voltage control. This paper proposes a novel control method of excitation system of ASGM for improving the transient stability of a multi-machine power system including multiple ASGMs. The controller which is designed based on an energy function works well for the stability enhancement. In comparison with the conventional excitation control of synchronous generator and constant output control of ASGM, the effectiveness of the proposed method is shown by digital simulations. 10 refs., 5 figs., 2 tabs.

  9. A New Generalized Two-Stage Direct Power Conversion Topology to Independently Supply Multiple AC Loads from Multiple Power Grids with Adjustable Power Loading

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

    Normally, a power converter has one supply port to connect to the power grid and one output port to connect to an AC load that requires variable voltage and variable frequency. Converter topologies with multiple output ports, the so-called multi-drive converters are also used in order to share the...... cost of an active front-end rectifier. As the trend on the energy market is towards deregulation, new converter topologies are needed to allow independent producers/consumers to connect to multiple distribution grids in order to minimize the electricity price. Having the possibility to adjust smoothly...... angle) and continuously adjust these power fractions will become a desired feature. This paper presents a generalized Direct Power Converter topology, which is able to connect to multiple AC supplies proving complete decoupling and no circulating power between the input ports and to independently...

  10. Buck-Boost Control of Four Quadrant Chopper using Symmetrical Impedance Network for Adjustable Speed Drive

    Saswati Swapna Dash; Byamakesh Nayak

    2015-01-01

    This paper proposes buck-boost capabilities of four quadrant chopper for wide range speed control of DC motor drives using symmetrical impedance network called Z-source network. By controlling the shoot through duty ratio from 0 to 0.5 and non-shoot through techniques, the Z-source four quadrant choppers can produce any desired DC voltage across the DC motor. The switching patterns for both buck and boost operations are presented to achieve four modes of operation of DC motor. As a result, th...

  11. Buck-Boost Control of Four Quadrant Chopper using Symmetrical Impedance Network for Adjustable Speed Drive

    Saswati Swapna Dash

    2015-02-01

    Full Text Available This paper proposes buck-boost capabilities of four quadrant chopper for wide range speed control of DC motor drives using symmetrical impedance network called Z-source network. By controlling the shoot through duty ratio from 0 to 0.5 and non-shoot through techniques, the Z-source four quadrant choppers can produce any desired DC voltage across the DC motor. The switching patterns for both buck and boost operations are presented to achieve four modes of operation of DC motor. As a result, the proposed model will have ride through capability during voltage sags, manage during voltage swells, used in any types of DC voltage sources such as fuel cell and solar cell and improve the reliability by reducing EMI noise. Analysis and simulation results are presented to demonstrate these new findings.

  12. The Use of Active Elements to Reduce the Size and Weight of Passive Components in Adjustable Speed Drives

    Maheshwari, Ram Krishan

    shaft voltage, the common mode voltage, the conducted emissions, and the efficiency of the two systems are compared since they are major factors which affect the size of the passive components in the drives. Although the three-level inverter requires higher number of active components as compared to the......Adjustable speed drives are considered as workhorse of industry due to various applications in different kind of industries. According to a market survey, low voltage drives are most profitable in the drive industries. The drive consists of a machine and a converter, which processes grid power and...... converts into usable power for the machine. The converter consists of active and passive components. The size, weight, and volume of the drive are decided by the passive components since they typically contribute to 75% of the weight and volume of the drive. Most popular topology for the low voltage drive...

  13. 交流异步电动机调速系统控制策略综述%Review of AC asynchronous motor speed control strategy

    丁辉; 胡协和

    2011-01-01

    为了更精确地实现交流异步电动机调速,基于交流异步电动机的数学模型论述异步电动机变压变频(VVVF)调速系统的各种控制策略.总结早期的基于异步电机稳态模型的控制策略,介绍3种较成熟的基于动态模型的控制策略,分析现代控制理论在交流异步电动机调速系统中的应用,展望交流调速控制策略的发展方向.传统的控制策略在工业现场中的应用已经较为成熟,各种现代控制策略和先进控制算法则有广阔的发展前景.%Variable voltage variable frequency (VVVF) speed control strategies were researched based on the mathematical model of alternating current (AC) asynchronous motor in order to achieve more accurate speed control of AC induction motor. The early control methods of induction motor based on the steady-state model were simply summarized. Three mature control schemes based on the dynamic model were introduced. The application of modern control theory in AC asynchronous motor speed control system was analyzed. Finally, the future development direction of AC speed control strategy was given. Traditional strategies were maturely utilized in industrial field, but the modern control theory and advanced control algorithms still have vast potential for future development.

  14. Effects of priming exercise on the speed of adjustment of muscle oxidative metabolism at the onset of moderate-intensity step transitions in older adults.

    De Roia, Gabriela; Pogliaghi, Silvia; Adami, Alessandra; Papadopoulou, Christina; Capelli, Carlo

    2012-05-15

    Aging is associated with a functional decline of the oxidative metabolism due to progressive limitations of both O(2) delivery and utilization. Priming exercise (PE) increases the speed of adjustment of oxidative metabolism during successive moderate-intensity transitions. We tested the hypothesis that such improvement is due to a better matching of O(2) delivery to utilization within the working muscles. In 21 healthy older adults (65.7 ± 5 yr), we measured contemporaneously noninvasive indexes of the overall speed of adjustment of the oxidative metabolism (i.e., pulmonary Vo(2) kinetics), of the bulk O(2) delivery (i.e., cardiac output), and of the rate of muscle deoxygenation (i.e., deoxygenated hemoglobin, HHb) during moderate-intensity step transitions, either with (ModB) or without (ModA) prior PE. The local matching of O(2) delivery to utilization was evaluated by the ΔHHb/ΔVo(2) ratio index. The overall speed of adjustment of the Vo(2) kinetics was significantly increased in ModB compared with ModA (P ModA (P < 0.05), suggesting an improved O(2) delivery. Our data are compatible with the hypothesis that, in older adults, PE, prior to moderate-intensity exercise, beneficially affects the speed of adjustment of oxidative metabolism due to an acute improvement of the local matching of O(2) delivery to utilization. PMID:22422668

  15. Six-step Voltage Control of PM Brushless AC Motors under High Speed Flux-weakening Operation for EV/HEV Applications

    诸自强

    2008-01-01

    The torque-speed characteristics of brushless motor having an interior permanent magnet rotor and a sinusoidalback-emf waveform are compared experimentally when it is operated in brushless AC (BLAC) mode and brushless DC(BLDC) modes with both 2-phase, 120° conduction (BLDC-120) and 3-phase,180° conduction (BLDC-180).Particularemphasis is on high-speed,six-step voltage controlled,flux-weakening operation.h is shown that for EV/HEV applications,even for interior PM brushless motors which have sinusoidal back-emf waveforms,in order to achieve maximum torque perampere capability over wide operation speed range,it is advantageous to employ a hybrid operation mode-BLAC operationin the constant torque region and six-step voltage control (BLDC-180 operation, together with current phase control) inthe flux-weakening region.

  16. Power compensation effect of an adjustable-speed rotary condenser with a flywheel for a large capacity magnet power supply

    Akagi, Hirofumi; Sato, Hikaru

    1999-01-01

    Direct connection of the synchrotron magnet power supply to the utilities causes the effect of pulsed reactive and active power in the AC line. Conventionally, Static Var Control system compensates the reactive power generated by the thyristor converter to reduce the flicker in the power line. However, it is necessary to control not only a reactive power but also an active power for the future large scale synchrotron magnet power supply in order to reduce the dissipation power and to realize ...

  17. Possibilities of increased power output from existing generator plants. Feasible changes of existing generators. New technology, ASD (Adjustable Speed Drives); Muligheter for oekt effekt fra eksisterende generatoranlegg. Mulige endringer av bestaaende generatorer. Ny teknologi, ASD (Adustable Speed Drives)

    Elstroem, A.

    1996-12-31

    The present paper relates to the increase of power output from existing generator plants in Norway by new operation profiles. The paper focuses on the consequences of increasing the power turnover and production with a particular attention to the generator itself. In addition, some of the possibilities on the use of an ASD (Adjustable Speed Drives) installation are elucidated, which is a concept on regulating the number of revolutions within small limits by synchronous rotation. According to the author, the power output of generator increases between 10 to 30%

  18. Structure of 15-Level Sub-Module Cascaded H-Bridge Inverter for Speed Control of AC Drive Applications

    R. Uthirasamy

    2015-02-01

    Full Text Available This paper deals with the implementation of a single phase 15-level Sub-Multilevel Cascaded H-Bridge Inverter (SMCHBI for variable speed industrial drive applications. It consists of sub-multilevel modules and H-bridge inverter configuration. Sub-multilevel switches synthesize stepped DC link voltage and current from the DC sources. H-bridge inverter switches renovate stepped DC link voltage and current into sinusoidal waveform. Compared with conventional Cascaded Multilevel Inverter (CMLI, the proposed system employs the reduced number of power switches, DC sources and gate driver requirements. The proposed system not only reduces the overall system cost but also reduces the voltage stress across the inverter switches. The proposed system does not required additional resonant soft switching circuits for Zero Voltage Switching (ZVS of inverter. In the proposed method, variable frequency method is adopted for the speed control of industrial induction motor drives. A prototype model of 15-level SMCHB is developed and the performance of the systems is validated experimentally.

  19. SYSTEMS FOR THE ADJUSTMENT OF THE MAIN KINEMATIC CHAIN OF THE VERTICAL TURNING LATHES

    Dan PRODAN

    2011-07-01

    Full Text Available This paperwork presents some systems for the adjustment of the main kinematic chains of theVertical Turning Lathes that have been used within the last 20 years. There are presented adjustment systemsused when having the machine equipped with older type motors, with only one speed, and also modern systemsfor which A.C. motors with the speed adjustable by frequency variation are needed. It insists on the presentrole of the “gearboxes” as torque multipliers and not as speed reducer.

  20. 炼钢转炉除尘风机的变频调速节能运行%OPERATION OF ELECTRICITY-SAVING OF AC FREQUENCY MODULATION FOR SPEED REGULATION OF DEDUSTING FAN OF STEEL-MAKING CONVERTER

    陈乐柱

    2001-01-01

    介绍了转炉炼钢的工况及节能特点,提出了变频调速在转炉除尘风机上的实施及使用方法。%The paper introduces the working process and electricity-saving characteristics of steel-making,and puts forward the operation and application of AC frequency modulation for speed regulation used in dedusting fan of converter.

  1. Modern control theory and speed adjustment of AC motor%现代控制理论与交流电机调速(Ⅰ)

    黄济荣

    2005-01-01

    自适应控制作为现代控制理论的一个分支,在电机调速系统中起着重要的作用.特别是在磁场定向解耦控制中,通过自适应控制或校正技术将能够正确决定磁场的位置和大小,保证磁场与转矩的解耦控制.文章的这一部分从电机的动态模型和状态方程出发,阐明参数随工作点变化而呈现的不确定性的特点;并着重介绍自适应控制或校正算法的原理和方法应用.

  2. Fault Tolerant Three-Phase AC Motor Drive Topologies:A Comparison of Features, Cost, and Limitations

    2005-01-01

    THE RELIABILITY of adjustables peed ac motor drives is an area of great interest for all members of the drives community and marketplace. This is particularly the case for the military, aerospace and automotive industries that are increasingly adopting variable speed drives in order to improve overall system efficiency and performance. There are certain safety critical applications such as steering, fuel pumps,

  3. 基于剔除机械效应的资本结构调整速度再检验%The Retest of Capital Structure′s Adjustment Speed Based on Exclusion of Mechanical Effects

    顾乃康; 邓剑兰

    2014-01-01

    The reason why research on capital structure′s adjustment speed has not yet won unanimous conclusion is that there may be a “mechanical effect” in conventional partial adjustment model .By decomposing the accounting identity of asset-liability ratio, this paper eliminates the mechanical effects caused by the change in asset size .And based on panel data of listed compa-nies in Shenzhen Stock Market and Shanghai Stock Market from 1998 to 2011 which issue A-shares only , this paper uses the two-stage estimation method to retest the adjustment speed and mean reversion of capital structure which are caused by active finan -cing behaviors of corporates .The empirical results show that:The adjustment speed of capital structure is about 13%under tra-ditional estimation which uses the change of asset-liability ratio as the dependent variable;but after excluding mechanical effects caused by changes in assets , the adjustment speed significantly drops to around 5%.The results show that , by excluding such mechanical effects , the corporate financing behaviors still induce mean reversion phenomenon of capital structure , but the speed of adjustment is so low that the trend of mean reversion is not obvious .%关于资本结构调整速度的研究至今仍未获得一致结论的原因之一在于传统的部分调整模型可能存在机械效应。通过对账面资产负债率的会计恒等式进行分解,剔除由资产规模变动引起的机械效应,在此基础上以1998年至2011年中国仅发行A股的非金融类上市公司面板数据为样本,采用两阶段估计法重新检验企业主动的融资行为对资本结构调整速度和均值反转的影响。研究结果表明,在传统的采用资产负债率变动作为因变量的估计下得到的资本结构调整速度约为13%,而剔除由资产规模变动引起的机械效应之后估计得到的调整速度明显下降到5%左右。这意味着在剔除由资产规模变动引起

  4. Design and simulation of full digital SVPWM AC speed control system%全数字化SVPWM调速系统的设计与仿真

    刘刚利

    2011-01-01

    The implementation scheme to realize vector variable speed system using low -cost embedded system was presented in this paper.The design of the system software, hardware was optimized, and simulation was carried out.Simulation results demonstrated that the performance of space vector variable speed system was excellent, all parts of the theoretical analysis were correct, parameters were set comparatively appropriate, voltage and current output waveforms met the requirements, speed met the beat control requirements, and there was almost no oscillation.The system design is instructive to control production costs and increase commonality, and the system simulation is important to produce the prototype, shorten the design cycle and improve production efficiency.%该文提出了使用价格低廉的嵌入式系统实现矢量变频调速系统的实施方案,对系统软件、硬件设计进行了优化,并实施仿真.仿真表明,设计的空间矢量变频调速系统性能优异,各个部分的理论分析正确,参数配合比较恰当,电压、电流输出波形达到要求,转速符合最少拍控制要求,基本无振荡.系统的设计对控制生产成本、增强通用性具有指导意义,系统的仿真对样机制作、缩短设计周期、提高生产效率具有重要意义.

  5. 气量无级调节系统的原理及应用%Principle and Application of HydroCOM Stepless Speed Adjustment System

    陈睿

    2012-01-01

    石油化工装置中的往复式压缩机常采用仪表阀旁路回流进行流量调节,造成大量能耗浪费。但在往复式压缩机上实施HydroCOM无级调节系统后,节能降耗效果十分显著。本文阐述了HydroCOM无级调节系统的节能原理、控制方案和联锁逻辑。%The bypass valve was often used to adjust the flow in reciprocating compressor in petrochemical plant, then a lot of energy were wasted. After HydroCOM system applied in reciprocating compressor, energy was saved a great deal. The principle of energy saving, the control program and the interlock logic were describled in detail.

  6. Relationship between robust stability and power system damping enhancement by excitation control system of adjustable-speed generator; Kahensoku hatsudenki reiji denatsu seigyo kei ni yoru denryoku keito danpingu kojo koka to robasuto anteisei no kankei

    Shigeto, T.; Yokoyama, A. [Tokyo Univ. (Japan)

    1997-12-20

    Since Adjustable-Speed Generator (ASG) is excited by alternative voltage fed by a quick-response cycloconverter, the rotor speed can be changed continuously. The ASGs installed at sonic pumping-up power stations are now utilized for Automatic Frequency Control at night time and under the light load condition by changing the pumping-up power due to the rotating speed change. It is expected. on the other hand. that under the generating condition at day time ASG will be utilized for improvement of power system stability because it can change the active power and the reactive power independently of each other. This paper presents the effect of the excitation control system of ASG designed by robust pole allocation method which is one of the controller design techniques besed on H{infinity} control theory, on the power system damping enhancement. Eigenvalue analysis and digital time simulation are carried out for 10-machine longitudinal test power system including ASGs in order to evaluate the designed controller. 5 refs., 23 figs., 5 tabs.

  7. Robust Non-Linear Direct Torque and Flux Control of Adjustable Speed Sensorless PMSM Drive Based on SVM Using a PI Predictive Controller

    F. Naceri

    2010-01-01

    Full Text Available This paper presents a new sensorless direct torque control method for voltage inverter – fed PMSM. The control methodis used a modified Direct Torque Control scheme with constant inverter switching frequency using Space Vector Modulation(DTC-SVM. The variation of stator and rotor resistance due to changes in temperature or frequency deteriorates theperformance of DTC-SVM controller by introducing errors in the estimated flux linkage and the electromagnetic torque.As a result, this approach will not be suitable for high power drives such as those used in tractions, as they require goodtorque control performance at considerably lower frequency. A novel stator resistance estimator is proposed. The estimationmethod is implemented using the Extended Kalman Filter. Finally extensive simulation results are presented to validate theproposed technique. The system is tested at different speeds and a very satisfactory performance has been achieved.

  8. Theoretical and experimental investigation into anti-idling A/C system for trucks

    Highlights: • A mathematical model is developed and verified using a built test-bed. • Thermal and performance characteristics of an anti-idling truck A/C system are investigated. • It is shown that variable speed fans have significant effects on the COP in different conditions. • A point of optimum COP can be found by changing the fans speed for any operating condition. • Anti-idling A/C systems equipped to variable speed control can significantly save environment. - Abstract: In this study, a recently developed truck anti-idling air conditioning (A/C) system is investigated. A mathematical model is developed to simulate the thermodynamic and heat transfer characteristics of the A/C system and calculate the coefficient of performance (COP). Utilizing environmental chambers and a number of measuring equipment, an experimental setup is built to verify the accuracy of the mathematical model and to perform a comprehensive study on the performance of the system for a wide range of operating conditions. A good agreement between the simulation and the experimental data, with a maximum discrepancy of 10.6%, is achieved. The results show a range of 0.5–1.7 for the system COP under a variety of operating condition. The parametric study shows that for any cooling demand, ambient and indoor air temperatures, there is a point of optimum COP that can be achieved by adjusting the condenser and evaporator fans speed

  9. ADJUSTMENT FACTORS AND ADJUSTMENT STRUCTURE

    Tao Benzao

    2003-01-01

    In this paper, adjustment factors J and R put forward by professor Zhou Jiangwen are introduced and the nature of the adjustment factors and their role in evaluating adjustment structure is discussed and proved.

  10. Adjustment of the Short Track Speed Skaters'Psychology in Starting%短道速滑运动员起跑心理状态的调整

    耿丽; 刘翠佳

    2011-01-01

    比赛中短道速滑的起跑,对于整个比赛的过程和最终取得成绩起着至关重要的作用。运动员起跑时不良起跑心理状态表现为训练和比赛动机障碍、过度紧张性情绪障碍、焦虑性情绪障碍、抑制障碍,提出采取消除紧张情绪、消除焦虑和畏惧情绪、生物反馈法、集中注意力、念动训练法等方法与手段调整运动员赛前的心理状态。%The starting is crucial for a short track speed skater to perform through a competition and catch the final result. The skaters'bad psychology in starting shows the motivational perplexity of training and competition, the emotional handicap of overstrain and anxiety, the disorder of inhibitory control. The paper suggests clearing up their feelings of nervousness, anxiety and fear with the methods and means of biofeedback, focusing attention, ideomotion training.

  11. Induction Motor Control through AC/DC/AC Converters

    Elfadili, Abderrahim; Giri, Fouad; Ouadi, Hamid; El Magri, Abdelmounime; Dugard, Luc; Abouloifa, Abdelmajid

    2010-01-01

    We consider the problem of controlling inductions motors driven through AC/DC rectifiers and DC/AC inverters. The control objectives are threefold: (i) forcing the motor speed to track a reference signal, (ii) regulating the DC Link voltage, (iii) assuring a satisfactory power factor correction (PFC) with respect to the power supply net. First, a nonlinear model of the whole controlled system is developed in the Park-coordinates. Then, a nonlinear multi-loop controller is synthesized using th...

  12. Occupational Adjustment of Immigrants

    Zorlu, Aslan

    2011-01-01

    This paper examines the speed of the occupational adjustment of immigrants using Labour Force Surveys 2004 and 2005 from Statistics Netherlands. The analysis provides new evidence that immigrants start with jobs at the lower levels of skill distribution. Their occupational achievement improves significantly with the duration of residence. The extent of this initial disadvantage and the rate of adjustment vary across immigrant groups according to the transferability of skills associated with t...

  13. Research on flutter test technology of continuously adjusting dynamical pressure in high-speed wind tunnel%高速风洞连续变速压颤振试验技术研究

    郭洪涛; 闫昱; 余立; 吕彬彬; 杜宁

    2015-01-01

    针对高速暂冲式风洞阶梯变速压颤振试验用时长、耗气量大和试验模型有效使用寿命短等缺点,开展了高速暂冲式风洞连续变速压颤振试验技术研究,解决了定 Ma 数连续变速压流场控制技术与连续变速压工况下的颤振试验数据处理技术等难题。具体技术措施是:在2.4m×2.4m 暂冲式跨声速风洞中设计了基于运动函数的定Ma 数线性变总压控制策略,使 Ma 数控制精度达到了0.005以内且速压无超调,实现了流场控制目标;采用 Pick-Hold 方法构建颤振边界的亚临界预测判据,并根据预测判据近似于正态分布的特点,基于数理统计的参数估计法来减小预测判据的散布度,从而提高颤振边界亚临界预测的准确性。风洞验证试验结果表明,该试验技术达到了工程实用化水平,不仅能够取得与阶梯变速压颤振试验技术一致的结果,还能极大地节省耗气量,经济效益显著。%According to the defects shown in the flutter tests of stepped adjusting dynamical pressure in high speed intermittent wind tunnel,such as:long testing time,high gas consump-tion,and short acceptable life of testing models,researches on flutter test technology of continu-ously adjusting dynamical pressure in high-speed intermittent wind tunnels are conducted.Tech-nical problems of flutter test data processing and wind tunnel flow controlling have mainly been solved.The specific approaches are:in the 2.4m×2.4m blow off transonic wind tunnel,fixed Mach number and linear varying total pressure controlling strategies based on movement function are presented,and thus the flow controlling goal of fixed Mach number continuously adjusting dynamical pressure is achieved.The controlling uncertainty of Mach number reaches less than 0.005 without deviation of dynamical pressure.The Pick-Hold method is adopted to set up the subcritical prediction criterion in flutter boundary

  14. Research and design on synchronizing belt adjusting device of high-speed stocking machine%高速丝袜机同步带调节装置的研究与设计

    胡国军; 冯方

    2013-01-01

    根据实际生产及使用需要,要求高速丝袜机同步带的松紧能够调节。无论国内还是国外的高速丝袜机,其同步带的松紧均由机器的底座、同步带轮及同步带的制造精度所决定。而且使用一段时间后同步带有可能会松弛,严重影响机器的使用。针对这一问题,设计了一套结构简单、使用方便且可以随时调节同步带松紧的调节装置,降低了零件的生产精度,延长了同步带的使用寿命,为机器的制造商与用户提供了便利。%According to the requirement of practical production and usage ,the tightness degree for the synchronizing belt of high-speed stocking machine need adjust .Whenever the machine is manufactured at home or abroad ,the tightness of synchronizing belt is determined by the machine base ,the synchronizing belt pulley ,and the manufacturing accuracy of the belt .If the belt is used for long-time,the fatigue problem will be produced ,which could result in the serious usage .A set of creative adjusting device with the simple construct ,convenient using and timely adjusting the tightness of synchronizing belt is designed to solve the above prob -lem,which could not only decrease the production accuracy of parts ,but prolong the usage lifetime of the belt to offer the conven-ience for the machine manufacturer and custom .

  15. Convexity Adjustments

    M. Gaspar, Raquel; Murgoci, Agatha

    2010-01-01

    A convexity adjustment (or convexity correction) in fixed income markets arises when one uses prices of standard (plain vanilla) products plus an adjustment to price nonstandard products. We explain the basic and appealing idea behind the use of convexity adjustments and focus on the situations o...

  16. Adjustment disorder

    American Psychiatric Association. Diagnostic and statistical manual of mental disorders . 5th ed. Arlington, VA: American Psychiatric Publishing. 2013. Powell AD. Grief, bereavement, and adjustment disorders. In: Stern TA, Fava ...

  17. Adjustment disorder

    American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, Va: American Psychiatric Publishing. 2013. Powell AD. Grief, bereavement, and adjustment disorders. In: Stern TA, Rosenbaum ...

  18. Modern control theory and speed adjustment of AC motor--Nonlinear decoupling control%现代控制理论与交流电机调速(Ⅵ)--非线性解耦控制

    黄济荣

    2005-01-01

    提出一种基于微分几何的精确反馈线性化控制方法,介绍其基本概念及在交流电机调速系统中的应用原理.分析了磁场定向控制的局限性,即它只能获得渐近的输入-输出线性化和解耦.而采用基于微分几何的精确反馈线性化方法,即使在磁场变化的情况下系统暂态响应也是解耦的,这有利于改善交流电机这类具有非线性特征的电气传动系统的性能.

  19. 现代控制理论与交流电机调速(Ⅴ)--滑模变结构控制%Modern control theory and speed adjustment of AC motor --variable structure control with sliding mode

    黄济荣

    2005-01-01

    介绍变结构系统的基本概念、数学表达设计问题及其在交流电机调速系统中的应用.阐述滑模理论在变结构系统中的重要作用.指出设计变结构控制系统的核心思想是通过不连续控制,强迫这种类型的运动朝向状态空间的某个特定区域(滑动流形)并保持下去;同时指出,对于非线性不确定性系统,采用滑模变结构控制可能使跟踪误差最小化,并使复杂过程与系统控制的工程实现相对简单.

  20. Modern control theory and speed adjustment of AC motor--Intelligent control%现代控制理论与交流电机调速(Ⅳ)--智能控制(3)

    黄济荣

    2005-01-01

    针对模糊逻辑控制和神经网络控制这2种控制方法的长处和不足,人们又提出兼具两者优点的神经网络-模糊控制方法.介绍了神经网络-模糊控制系统合成推理的网络形式及一般结构,并举例阐述系统在交流电机调速中的应用情况.

  1. 现代控制理论与交流电机调速(Ⅲ)--智能控制(2)%Modern control theory and speed adjustment of AC motor--Intelligent control

    黄济荣

    2005-01-01

    介绍在交流电机调速中应用智能控制的第二部分--人工神经网络控制技术.这种网络由基本处理单元--人工神经元构成,它的输出包含一个非线性的响应函数,因此人工神经网络适于处理诸如交流电机一类具有明显非线性特征的系统.通过不同方式的训练,连续修正网络内连接权的大小,可将其用于交流电机的系统辨识和控制.

  2. 现代控制理论与交流电机调速(Ⅱ)--智能控制(1)%Modern control theory and speed adjustment of AC motor--Intelligent control

    黄济荣

    2005-01-01

    人工智能系统将进一步与电力电子学以及运动控制相结合而更加深刻地影响后者的发展.特别是在研制高质量的传动和伺服控制装置中.文章着重介绍模糊逻辑控制、神经网络控制以及它们的交叉结合的神经网络-模糊控制系统及其应用与设计.

  3. Salary adjustments

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, the following elements do not increase: a)\tFamily Allowance, Child Allowance and Infant Allowance (Annex R A 3); b)\tReimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be applied, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and rounding effects. Human Resources Department Tel. 73566

  4. Salary adjustments

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, following elements do not increase: a) Family Allowance, Child Allowance and Infant Allowance (Annex R A 3). b) Reimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be implemented, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and the rounding effects. Human Resources Department Tel. 73566

  5. Speeding Up

    YU SHUJUN

    2010-01-01

    In the wake of the global financial crisis, China has amazed the world with the speed of its economic recovery. But what has been even more surprising is the speed of its railway evolution. The unveiling of the 1,069-km Wuhan-Guangzhou High-speed Railway on December 26, 2009 pushed China's high-speed rail sys-tem-the total mileage, the average speed and the technology-to rank first in the world almost overnight.

  6. Adjustable collimator

    In a rotating fan beam tomographic scanner there is included an adjustable collimator and shutter assembly. The assembly includes a fan angle collimation cylinder having a plurality of different length slots through which the beam may pass for adjusting the fan angle of the beam. It also includes a beam thickness cylinder having a plurality of slots of different widths for adjusting the thickness of the beam. Further, some of the slots have filter materials mounted therein so that the operator may select from a plurality of filters. Also disclosed is a servo motor system which allows the operator to select the desired fan angle, beam thickness and filter from a remote location. An additional feature is a failsafe shutter assembly which includes a spring biased shutter cylinder mounted in the collimation cylinders. The servo motor control circuit checks several system conditions before the shutter is rendered openable. Further, the circuit cuts off the radiation if the shutter fails to open or close properly. A still further feature is a reference radiation intensity monitor which includes a tuning-fork shaped light conducting element having a scintillation crystal mounted on each tine. The monitor is placed adjacent the collimator between it and the source with the pair of crystals to either side of the fan beam

  7. 76 FR 74720 - Inflation Adjustment of Civil Monetary Penalties; Correction

    2011-12-01

    ..., 2009 (74 FR 38114). The rule adjusts for inflation the maximum amount of each statutory civil penalty... 46 CFR Part 506 RIN 3072-AC36 Inflation Adjustment of Civil Monetary Penalties; Correction AGENCY... Civil Penalties Inflation Adjustment Act of 1990, as amended by the Debt Collection Improvement Act...

  8. Circuit Regulates Speed Of dc Motor

    Weaver, Charles; Padden, Robin; Brown, Floyd A., Jr.

    1990-01-01

    Driving circuit regulates speed of small dc permanent-magnet motor in tape recorder. Two nested feedback loops maintain speed within 1 percent of constant value. Inner loop provides coarse regulation, while outer loop removes most of variation in speed that remains in the presence of regulation by the inner loop. Compares speed of motor with commanded speed and adjusts current supplied to motor accordingly.

  9. Adaptive Nonlinear Control of Induction Motors through AC/DC/AC Converters

    Elfadili, Abderrahim; Giri, Fouad; El Magri, Abdelmounime; Dugard, Luc; Chaoui, Fatima Zara

    2012-01-01

    The problem of controlling induction motors, together with associated AC/DC rectifiers and DC/AC inverters, is addressed. The control objectives are threefold: (i) the motor speed should track any reference signal despite mechanical parameter uncertainties and variations; (ii) the DC Link voltage must be tightly regulated; (iii) the power factor correction (PFC) w.r.t. the power supply net must be performed in a satisfactory way. First, a nonlinear model of the whole controlled system is deve...

  10. Robust control of synchronous motors through AC/DC/AC converters

    El Magri, Abdelmounime; Giri, Fouad; Abouloifa, Abdelmajid; Chaoui, Fatima Zara

    2010-01-01

    The problem of controlling synchronous motors, driven through AC/DC rectifiers and DC/AC inverters is addressed. The control objectives are three fold: (i) forcing the motor speed to track a varying reference signal in presence of motor parameter uncertainties;(ii) regulating the DC Link voltage; (iii )assuring a satisfactory power factor correction (PFC) with respect to the power supply net .First, a nonlinear model of the whole controlled system is developed in the Park-coordinates. Then, a...

  11. Measured speed versus true speed

    Perez, Israel

    2010-01-01

    The theoretical predictions, derived from the Lorentz and the Tangherlini transformations, for the one-way speed of any physical entity are confronted with the corresponding expressions for the one-way measured speed obtained from a gedanken experiment. The experiment demonstrates that, for an inertial frame $K'$ in motion relative to an inertial frame $K$ where the one-way speed of light is isotropic, even the special theory of relativity renders the one-way speed of light as function of the...

  12. An Improved AC-BM Algorithm for Monitoring Watch List

    Mo Yiwen

    2013-07-01

    Full Text Available With the expanding of database of the watch list of anti-money laundering, improving the speed in matching between the watch list and the database of account holders and clients’ transaction is especially important. This paper proposes an improved AC-BM Algorithm, a matching algorithm of subsection, to improve the speed of matching. Experiment results show the time performance of the improved algorithm is better than traditional BM algorithm, AC algorithm and the AC-BM algorithm. It can improve the efficiency of on-line monitoring of anti-money laundering.  

  13. Research on the variable speed system of large power alternating current motor%Research on the variable speed system of large power alternating current motor

    Li Chongjian

    2012-01-01

    The development status of the variable speed system of large power AC (alternating current) motor drive in China is introduced. The large power AC drive fed by AC-AC converters (cycloconverters) has developed greatly, and some innovations on the theory and engineering technique have been realized. They have been applied to rolling mills, mine hoists, and so on, and remarkable economic and social benefit has been achieved. The development of AC drive fed by large power IGCT (integrated gate commutated thyristors) AC-DC-AC converter is also introduced. It has excellent performance and reliable operation, and has been used in traction.

  14. AC electric motors control advanced design techniques and applications

    Giri, Fouad

    2013-01-01

    The complexity of AC motor control lies in the multivariable and nonlinear nature of AC machine dynamics. Recent advancements in control theory now make it possible to deal with long-standing problems in AC motors control. This text expertly draws on these developments to apply a wide range of model-based control designmethods to a variety of AC motors. Contributions from over thirty top researchers explain how modern control design methods can be used to achieve tight speed regulation, optimal energetic efficiency, and operation reliability and safety, by considering online state var

  15. Application of ACS6000C Cycloconverter in the Hoist System of Coal Mine%ACS6000C交流调速技术在矿井提升系统的应用

    孟强; 廉鲁炜

    2013-01-01

    本文介绍一种全数字可编程模块化交流调速控制系统,ABB公司ACS6000C系统,其独特的应用和电机控制处理板(AMC3板),能进行高速动态信息处理以及对专门的控制系统进行调节和控制,在矿井提升机同步电机的调速控制应用中显现出高性能的响应和精确的力矩控制。实现了矿井提升机的安全、高效、稳定运行。%This paper introduces a digital programmable modular AC speed control system, ACS6000C system of ABB company, the applica-tion and motor unique control board (AMC3 board), can make high speed dynamic information processing and control and adjust the control system of the special, in the synchronous motor in mine hoist control showing response high performance and precise torque control applica-tions. The mine hoist safe, efficient and stable operation of machine.

  16. Hierarchical Control Strategy of Reactive Power for Wind Farm Based on the Front-End Speed Adjusting Wind Turbine%基于前端调速式风电机组的风电场无功分层控制策略

    燕尧; 董海鹰

    2015-01-01

    前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化引起的并网点电压波动问题,提出一种前端调速式风电场无功电压分层控制策略。该策略确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。%The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability, aiming at prob-lems in the wind farm which consists of the front-end speed adjusting wind turbine existing the grid connection node voltage fluctuation which is caused by the change of wind power, this paper proposes a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm.The strategy firstly determines selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains reactive power demand of the whole wind farm with the tuning control.The minimum real power loss of the wind farm is used as the objective function, based on the im-proved genetic algorithm optimization, and combines the reactive power output of the static synchronous compensator to adjust the reactive power output of the whole wind farm, so as to achieve the purpose of maintaining the voltage stability of the control point.The simulation results prove the feasibility and effectiveness of the strategy.

  17. Hierarchical control strategy of reactive power for wind farm based on the composition of the front-end speed adjusting wind turbine%基于前端调速式风电机组的风电场无功分层控制策略*

    燕尧; 董海鹰

    2015-01-01

    前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化而引起的并网点电压波动的问题,提出了一种前端调速式风电场无功电压分层控制策略。该策略首先确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。%The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability. Aiming at the wind farm with the front-end speed adjusting wind turbine exists grid connection node voltage fluctuation problem caused by the change of wind power, a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm is proposed. The strategy determines the selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains the reactive power demand of the whole wind farm by the tuning control. The minimum real power loss of the wind farm is used as objective function to allocate to each wind turbine based on the optimized and improved genetic algorithm. The strategy combines the reactive power output of the Static Synchronous Compensator to adjust the reactive power output of the whole wind farm and thus to achieve the purpose of maintaining the voltage stability of the control point. The simulation results prove the feasibility and effectiveness of the strategy.

  18. 基于前端调速式风电机组的风电场无功分层控制策略*%Hierarchical control strategy of reactive power for wind farm based on the composition of the front-end speed adjusting wind turbine

    燕尧; 董海鹰

    2015-01-01

    The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability. Aiming at the wind farm with the front-end speed adjusting wind turbine exists grid connection node voltage fluctuation problem caused by the change of wind power, a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm is proposed. The strategy determines the selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains the reactive power demand of the whole wind farm by the tuning control. The minimum real power loss of the wind farm is used as objective function to allocate to each wind turbine based on the optimized and improved genetic algorithm. The strategy combines the reactive power output of the Static Synchronous Compensator to adjust the reactive power output of the whole wind farm and thus to achieve the purpose of maintaining the voltage stability of the control point. The simulation results prove the feasibility and effectiveness of the strategy.%前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化而引起的并网点电压波动的问题,提出了一种前端调速式风电场无功电压分层控制策略。该策略首先确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。

  19. 基于前端调速式风电机组的风电场无功分层控制策略%Hierarchical Control Strategy of Reactive Power for Wind Farm Based on the Front-End Speed Adjusting Wind Turbine

    燕尧; 董海鹰

    2015-01-01

    The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability, aiming at prob-lems in the wind farm which consists of the front-end speed adjusting wind turbine existing the grid connection node voltage fluctuation which is caused by the change of wind power, this paper proposes a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm.The strategy firstly determines selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains reactive power demand of the whole wind farm with the tuning control.The minimum real power loss of the wind farm is used as the objective function, based on the im-proved genetic algorithm optimization, and combines the reactive power output of the static synchronous compensator to adjust the reactive power output of the whole wind farm, so as to achieve the purpose of maintaining the voltage stability of the control point.The simulation results prove the feasibility and effectiveness of the strategy.%前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化引起的并网点电压波动问题,提出一种前端调速式风电场无功电压分层控制策略。该策略确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。

  20. ACAC Converters for UPS

    Rusalin Lucian R. Păun

    2008-05-01

    Full Text Available This paper propose a new control technique forsingle – phase ACAC converters used for a on-line UPSwith a good dynamic response, a reduced-partscomponents, a good output characteristic, a good powerfactorcorrection(PFC. This converter no needs anisolation transformer. A power factor correction rectifierand an inverter with the proposed control scheme has beendesigned and simulated using Caspoc2007, validating theconcept.

  1. Speed Control Of Induction Motor Using Dspic30f2023

    M. S. Aspalli; Laxmi

    2013-01-01

    AC motor drives are widely used to control the speed of conveyor systems, blower speeds, pump speeds, machine tool speeds and other applications that require variable speed with variable torque. The main aim of the work is to design and develop an electronic system that can be used to control the speed of a three phase induction motor.The speed of the three phase induction motor can be controlled by various methods. The stator frequency control is one of the simplest methods to control the sp...

  2. Speed mathematics

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  3. Adjustments and Depression

    Full Text Available ... to my SCI? How do I deal with depression and adjustment to my SCI? ☷ ▾ Page contents The ... the moment you are injured. Understanding adjustment and depression Adjustment to paralysis is a process of changing ...

  4. ac propulsion system for an electric vehicle

    Geppert, S.

    1980-01-01

    It is pointed out that dc drives will be the logical choice for current production electric vehicles (EV). However, by the mid-80's, there is a good chance that the price and reliability of suitable high-power semiconductors will allow for a competitive ac system. The driving force behind the ac approach is the induction motor, which has specific advantages relative to a dc shunt or series traction motor. These advantages would be an important factor in the case of a vehicle for which low maintenance characteristics are of primary importance. A description of an EV ac propulsion system is provided, taking into account the logic controller, the inverter, the motor, and a two-speed transmission-differential-axle assembly. The main barrier to the employment of the considered propulsion system in EV is not any technical problem, but inverter transistor cost.

  5. Train Operation Adjustment Based on Conflict Resolution for High-speed Rail%高速铁路单个列车运行冲突消解研究

    文超; 彭其渊; 陈芋宏

    2013-01-01

    为研究高速铁路列车运行冲突消解问题,提出了各类列车运行冲突单个冲突的消解策略.分析了平移运行线、交换运行线、变更停站和越行方案以及数学规划方法等4种冲突策略的含义.根据冲突消解代价计算的方法,以最小冲突消解代价为优化目标,研究了高速铁路到达间隔时间冲突和出发间隔时间冲突、区间冲突、到发线运用冲突运用平移运行线、交换运行线、变更停站和越行方案等三种策略进行冲突消解的方法和过程.%In order to study the issue of train running conflict resolution of high-speed rail, the strategies of single train running conflict resolution for various types of train running conflicts is proposed. The 4 conflict resolution strategies named parallel shift of trains running lines, exchange of trains running lines, change of stopping stations and overtaking scheme, mathematical programming method are analyzed. In according to the conflict resolution cost calculation method and aimed to the minimum conflict resolution cost, the conflict resolution method and process are studied. The conflict resolution of the arrival interval conflict, departure interval conflict, section occupation conflict, arrival and departure track utilization conflict are discussed on the basis the conflict resolution strategies of parallel shift of trains running lines, exchange of trains running lines, change of stopping stations and overtaking scheme.

  6. AC power supply systems

    An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

  7. Adjustable hybrid diffractive/refractive achromatic lens

    Valley, Pouria; Savidis, Nickolaos; Schwiegerling, Jim; Dodge, Mohammad Reza; Peyman, Gholam; N. Peyghambarian

    2011-01-01

    We demonstrate a variable focal length achromatic lens that consists of a flat liquid crystal diffractive lens and a pressure-controlled fluidic refractive lens. The diffractive lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping po...

  8. AcEST: DK950971 [AcEST

    Full Text Available optera acutorost... 37 0.66 tr|B1ACS6|B1ACS6_BALBN DMP1 (Fragment) OS=Balaenoptera ...bonaerens... 37 0.66 tr|B1ACS5|B1ACS5_BALED DMP1 (Fragment) OS=Balaenoptera edeni... GN=... 37 0.66 tr|B1ACS4|B1ACS4_BALBO DMP1 (Fragment) OS=Balaenoptera borealis ... 37 0.66 tr|B1ACS3|B1ACS3..._BALMU DMP1 (Fragment) OS=Balaenoptera musculus ... 37 0.86 tr|B1ACS1|B1ACS1_MEGNO DMP1 (Fragment) OS=Megapt...1ACS2_BALPH DMP1 (Fragment) OS=Balaenoptera physalus ... 37 1.1 tr|B1ACT6|B1ACT6_MESPE DMP1 (Fragment) OS=Me

  9. 银行授信影响了资本结构动态调整速度吗?--考虑样本选择偏误的实证分析%Do Lines of Credit Affect Capital Structure Adjustment Speed? Evidence from Dynamic Panel with Sample Selection

    常亮

    2015-01-01

    With the panel data of Chinese listed firms during the time period of 2001—2011, this paper empirically studies the effect of credit lines on the capital structure adjustment speed, based on the theoretical assumption that bank lines of credit could reduce financial constraints so as to reduce adjustment costs. Traditional dynamic panel estimation are flawed to the bias of sample selection, since credit firms are selected according to firm size and investment opportunity. This paper uses dynamic panel model with sample selection to overcome these shortcomings. The results show that credit firms perform a much faster speed of capital structure adjustment comparing with non-credit firms.%银行授信可以通过缓解企业融资约束来降低企业的资本结构调整成本,从而有效提高资本结构的动态调整速度。但同时,企业能否获得银行授信,受到公司规模、投资机会等因素的影响,具有明显的样本选择性。因此,本文基于中国上市公司2001—2011年数据,在控制了授信的样本选择偏误的条件下,得到以下可信的证据:获得授信的公司表现出较快的调整速度,而不控制样本选择偏误的普通动态面板方法会使得估计有偏。本文不仅为资本结构的动态权衡理论提供了支持,同时也突出了在分组回归中控制样本选择偏误的重要性。

  10. AC1 Wing

    Adrian DOBRE

    2010-03-01

    Full Text Available The AC1 wing replaces the old wing of the wind tunnel model AEROTAXI, which has been made at scale 1:9. The new wing is part of CESAR program and improves the aerodynamic characteristics of the old one. The geometry of the whole wing was given by FOI Sweden and position of AC1 wing must coincide with the structure of the AEROTAXI model.

  11. AC1 Wing

    Adrian DOBRE

    2010-01-01

    The AC1 wing replaces the old wing of the wind tunnel model AEROTAXI, which has been made at scale 1:9. The new wing is part of CESAR program and improves the aerodynamic characteristics of the old one. The geometry of the whole wing was given by FOI Sweden and position of AC1 wing must coincide with the structure of the AEROTAXI model.

  12. Adjustments and Depression

    Full Text Available ... depression and adjustment to my SCI? How do I deal with depression and adjustment to my SCI? ☷ ▾ ... following an SCI? What are the secondary conditions? I have no health insurance, what are my options? ...

  13. Annual Adjustment Factors

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  14. Adjustments and Depression

    Full Text Available ... adjustment and depression Adjustment to paralysis is a process of changing one's thoughts and feelings and is ... stem cell research? What is the clinical trials process? Get support Ask us anything Get a peer ...

  15. Adjustments and Depression

    Full Text Available ... course an adjustment period as you navigate your new normal. The most important point to remember is ... to rebuild one's identity and to find a new balance in relationships. The stages of adjustment can ...

  16. Touch Screen based Speed Control of Single Phase Induction Motor

    S. Mallika; W. Razia Sultana; Sarat Kumar Sahoo*

    2010-01-01

    This paper gives a brief idea of touch screen technology and its interfacing with a controller to control the speed of single phase induction motor. Here touch screen technology and Programmable System on Chip (PSOC) microcontroller concept is utilized which is less spaceconsumption and easy to design. The aim of this paper is to have remote sensing and speed control of an AC motor.

  17. On-Chip AC self-test controller

    Flanagan, John D.; Herring, Jay R.; Lo, Tin-Chee

    2009-09-29

    A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

  18. Jump Testing and the Speed of Market Adjustment

    Rasmussen, Torben B.

    Asymptotic properties of jump tests rely on the property that any jump occurs within a single time interval no matter what the observation frequency is. Market microstructure effects in relation to news-induced revaluation of the underlying variable is likely to make this an unrealistic assumption...

  19. Harmonic Calculation Toolbox in Industry Application for Adjustable Speed Drive

    Asiminoaei, Lucian; Blaabjerg, Frede; Hansen, Steffan

    2004-01-01

    Previous to electrical installation of large power non-linear loads, a comprehensive design-study is often required in order to determine if the overall installation complies with international regulations in respect to harmonics. Current THD voltage distortion and power factor are just few...

  20. Harmonic Calculation Software for Industrial Applications with Adjustable Speed Drives

    Asiminoaei, Lucian; Hansen, S.; Blaabjerg, Frede

    2005-01-01

    This paper describes the evaluation of a new harmonic software. By using a combination of a pre-stored database and new interpolation techniques the software can very fast provide the harmonic data on real applications. The harmonic results obtained with this software have acceptable precision even...... with limited input data. The evaluation concludes here that this approach is very practical compared to other advanced harmonic analysis methods. The results are supported by comparisons of calculations and measurements given in an industrial application....

  1. Development of a hardware-based AC microgrid for AC stability assessment

    Swanson, Robert R.

    As more power electronic-based devices enable the development of high-bandwidth AC microgrids, the topic of microgrid power distribution stability has become of increased interest. Recently, researchers have proposed a relatively straightforward method to assess the stability of AC systems based upon the time-constants of sources, the net bus capacitance, and the rate limits of sources. In this research, a focus has been to develop a hardware test system to evaluate AC system stability. As a first step, a time domain model of a two converter microgrid was established in which a three phase inverter acts as a power source and an active rectifier serves as an adjustable constant power AC load. The constant power load can be utilized to create rapid power flow transients to the generating system. As a second step, the inverter and active rectifier were designed using a Smart Power Module IGBT for switching and an embedded microcontroller as a processor for algorithm implementation. The inverter and active rectifier were designed to operate simultaneously using a synchronization signal to ensure each respective local controller operates in a common reference frame. Finally, the physical system was created and initial testing performed to validate the hardware functionality as a variable amplitude and variable frequency AC system.

  2. Design of a Temperature Sensitive Voltage Regulator for AC Load using RTD

    Tasnuva Chowdhury,

    2010-12-01

    Full Text Available Voltage regulation of an electrical load has always been a necessity with the variation of atmospheric temperature. Human body undergoes troubles and sufferings when there is a certain change arises in the surrounding temperature and he or she might not be able to cope up with the sudden environmental change. To make life easier and better adjusted to the natural temperature change, a temperature sensitive voltage regulator have been designed and implemented in this work. Here a temperature sensor called Resistor Temperature Detector (RTD is used for temperature sensing purpose which delivers its output to the input of a voltage controller circuit and can subsequently control the speed of any light AC electrical load according to the variable temperature. In our project , the RTD was able to take the reading from 26oC to 38oC accurately. Moreover, the room temperature is also made visible by two 7-segment display. The circuit is synchronized and tested with the cheapest AC load (bulb availablein the market.

  3. Application of AC servo motor on the in-core neutron flux instrumentation system

    The application of ac servo motor in the In-Core Neutron Flux Instrumentation System is described. The hardware component of ac servo motor control system is different from the dc motor control system. The effect of two control system on the instrumentation system is compared. The ac servo motor control system can improve the accuracy of the motion control, optimize the speed control and increase the reliability. (authors)

  4. ac bidirectional motor controller

    Schreiner, K.

    1988-01-01

    Test data are presented and the design of a high-efficiency motor/generator controller at NASA-Lewis for use with the Space Station power system testbed is described. The bidirectional motor driver is a 20 kHz to variable frequency three-phase ac converter that operates from the high-frequency ac bus being designed for the Space Station. A zero-voltage-switching pulse-density-modulation technique is used in the converter to shape the low-frequency output waveform.

  5. Neural network based PWM AC chopper fed induction motor drive

    Venkatesan Jamuna

    2009-01-01

    Full Text Available In this paper, a new Simulink model for a neural network controlled PWM AC chopper fed single phase induction motor is proposed. Closed loop speed control is achieved using a neural network controller. To maintain a constant fluid flow with a variation in pressure head, drives like fan and pump are operated with closed loop speed control. The need to improve the quality and reliability of the drive circuit has increased because of the growing demand for improving the performance of motor drives. With the increased availability of MOSFET's and IGBT's, PWM converters can be used efficiently in low and medium power applications. From the simulation studies, it is seen that the PWM AC chopper has a better harmonic spectrum and lesser copper loss than the Phase controlled AC chopper. It is observed that the drive system with the proposed model produces better dynamic performance, reduced overshoot and fast transient response. .

  6. Repatriation Adjustment: Literature Review

    Gamze Arman

    2009-12-01

    Full Text Available Expatriation is a widely studied area of research in work and organizational psychology. After expatriates accomplish their missions in host countries, they return to their countries and this process is called repatriation. Adjustment constitutes a crucial part in repatriation research. In the present literature review, research about repatriation adjustment was reviewed with the aim of defining the whole picture in this phenomenon. Present research was classified on the basis of a theoretical model of repatriation adjustment. Basic frame consisted of antecedents, adjustment, outcomes as main variables and personal characteristics/coping strategies and organizational strategies as moderating variables.

  7. Theory of adaptive adjustment

    Weihong Huang

    2000-01-01

    Full Text Available Conventional adaptive expectation as a mechanism of stabilizing an unstable economic process is reexamined through a generalization to an adaptive adjustment framework. The generic structures of equilibria that can be stabilized through an adaptive adjustment mechanism are identified. The generalization can be applied to a broad class of discrete economic processes where the variables interested can be adjusted or controlled directly by economic agents such as in cobweb dynamics, Cournot games, Oligopoly markets, tatonnement price adjustment, tariff games, population control through immigration etc.

  8. AC/RF Superconductivity

    Ciovati, G.

    2015-01-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  9. AC/RF Superconductivity

    Ciovati, Gianluigi [JLAB

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  10. SoC-Based Dynamic Power Sharing Method with AC-Bus Voltage Restoration for Microgrid Applications

    Lu, Xiaonan; Sun, Kai; Guerrero, Josep M.; Huang, Lipei

    shared in the energy storage system. The relationship between the droop coefficient and SoC are studied deeply and the small signal model is developed to verify the stability of the control system. It is found that the active power sharing speed becomes faster with higher exponent of SoC. At the same...... time, in order to restore the AC-bus voltage, secondary control is employed to eliminate the deviations of the voltage frequency and amplitude caused by the droop control, with the droop coefficients adjusting according to the SoCs. The model of the secondary control scheme for SoC-based droop method...... is developed and its stability is discussed. The theoretical analysis is demonstrated by both simulation and experimental results....

  11. The Hardware Design of Parameter-Adjustable FIR Filter System

    Guosheng Xu

    2013-01-01

    This design using FPGA parallel architecture, high computing speed and high-speed reliability of USB2.0 interface, designed an FPGA + USB2.0 + computer FIR digital filter system, organically combining the speed of FPGA and flexibility of Computer through USB2.0 bus. The results demonstrated that the coefficients configuring of the system is easy, which can adjust the filter coefficients flexibly according to the actual demand, that it can effectively filter out the noise signals.

  12. ADJUSTABLE CHIP HOLDER

    2009-01-01

    An adjustable microchip holder for holding a microchip is provided having a plurality of displaceable interconnection pads for connecting the connection holes of a microchip with one or more external devices or equipment. The adjustable microchip holder can fit different sizes of microchips with ...

  13. Speed Regulator for Permanent Magnet DC Boring Machine

    2000-01-01

    In this paper a variable-speed system for a loaded permanent magnet direct current boring machine (PMDCBM) is described in details. The voltage adjustment of PMDCBM is accomplished by means of solid state switch with a high gain Darlington transistor. The device designed possesses good variable speed characteristic and Iow loss at low speed. The speed can be regulated automatically to hold at an ideal value according to the load.

  14. Speed controller for an alternating - current motor

    A controller for a multi-phase ac motor that is subject to a large inertial load, e.g. an induction motor driving a heavy spinning rotor of a neutron chopper that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal Esub(L) having a meandering line frequency, includes a sensor which provides a feedback pulse train representative of the actual speed of the motor which is compared (by counting clock pulses between feedback pulses) with a reference clock signal in a computing unit to provide a motor control signal Esub(c). The motor control signal is a weighted linear sum of a speed error signal, a phase error signal, and a drift error signal, the magnitudes of which are recalculated and updated with each revolution of the motor shaft. The speed error signal is constant for large speed errors but highly sensitive to small speed errors. The stator windings of the motor are driven by variable-frequency power amplifiers which are controlled by the motor control signal Esub(c) via PROMs which store digital representations of sine and cosine waveforms in quadrature. (author)

  15. Increased Ac excision (iae): Arabidopsis thaliana mutations affecting Ac transposition

    The maize transposable element Ac is highly active in the heterologous hosts tobacco and tomato, but shows very much reduced levels of activity in Arabidopsis. A mutagenesis experiment was undertaken with the aim of identifying Arabidopsis host factors responsible for the observed low levels of Ac activity. Seed from a line carrying a single copy of the Ac element inserted into the streptomycin phosphotransferase (SPT) reporter fusion, and which displayed typically low levels of Ac activity, were mutagenized using gamma rays. Nineteen mutants displaying high levels of somatic Ac activity, as judged by their highly variegated phenotypes, were isolated after screening the M2 generation on streptomycin-containing medium. The mutations fall into two complementation groups, iae1 and iae2, are unlinked to the SPT::Ac locus and segregate in a Mendelian fashion. The iae1 mutation is recessive and the iae2 mutation is semi-dominant. The iae1 and iae2 mutants show 550- and 70-fold increases, respectively, in the average number of Ac excision sectors per cotyledon. The IAE1 locus maps to chromosome 2, whereas the SPT::Ac reporter maps to chromosome 3. A molecular study of Ac activity in the iae1 mutant confirmed the very high levels of Ac excision predicted using the phenotypic assay, but revealed only low levels of Ac re-insertion. Analyses of germinal transposition in the iae1 mutant demonstrated an average germinal excision frequency of 3% and a frequency of independent Ac re-insertions following germinal excision of 22%. The iae mutants represents a possible means of improving the efficiency of Ac/Ds transposon tagging systems in Arabidopsis, and will enable the dissection of host involvement in Ac transposition and the mechanisms employed for controlling transposable element activity

  16. Hermetisk AC-Krets

    Hirsch, Carl; Smirnoff, Alexander

    2007-01-01

    Under sex månader våren 2007 har ett samarbete mellan Volvo Lastvagnar och två studenter från KTH, inriktning Integrerad produktutveckling vid institutionen för maskinkonstruktion, pågått i form av ett examensarbete på 20 poäng. Dagens AC-system i Volvos lastbilar avger 20-40 g/år av köldmediet R134a som är en kraftfull växthusgas. Detta sker främst genom diffusion via slangar och tätningsmaterial. Syftet med detta examensarbete är att ta fram förslag på tekniska lösningar på ett nytt AC-syst...

  17. Macroeconomic Situations and Policy Adjustments in China

    Dongjun Mao

    2009-01-01

    China has achieved wholly rapid growth, with economic reform and opening-up, since 1978. But the macro-economy is instable and showing prosperity and inflation, and Recession and deflation repeatedly with many times. Excessive fluctuations in the economy are due to macroeconomic policies’ amendments and adjustments, too loose or tight. Economic growth speeds up with macroeconomic fluctuations slowing down in recent years. Improvements in macroeconomic policies have played an important role. 2...

  18. Cascade Speed Control Of Dc Motor

    Anagha, Ranjith K; Anand C.P; Rahul Das; Anusha A.S

    2014-01-01

    Abstract: This paper presents a MATLAB aided Cascade designed controller to control and monitor the DC motor speed. First, design the driver circuit of the DC motor and use the microcontroller PIC16F877A to collect the feedback signals from the current sensor and optical encoder. The measured speed and current are serially transmitted to PC using RS232. By the MATLAB aided cascade controller, where inner loop is the current loop and outer loop is the speed loop, the parameters are adjusted to...

  19. Adjustments and Depression

    Full Text Available ... rebuild one's identity and to find a new balance in relationships. The stages of adjustment can include ... a peer mentor Advocate for change Fundraise with Team Reeve Champions Committee Volunteering About Us Our story ...

  20. Family Adjustment to Aphasia

    ... Public / Speech, Language and Swallowing / Disorders and Diseases Family Adjustment to Aphasia Richard S. was a senior manager ... It also presents a great challenge to the family. There may be tension among family members and ...

  1. Adjustments and Depression

    Full Text Available ... identity and to find a new balance in relationships. The stages of adjustment can include grieving, taking ... treatment options. Related pages What is a complete vs incomplete injury? What emergency procedures occur following an ...

  2. Adjustments and Depression

    Full Text Available ... thoughts and feelings and is something that takes time. The goal of adjusting is to rebuild one's ... updates about our impact > Get the Reeve newsletter International support > Pages in other languages Made with ♡ in ...

  3. KVA: Capital Valuation Adjustment

    Andrew Green; Chris Kenyon

    2014-01-01

    Credit (CVA), Debit (DVA) and Funding Valuation Adjustments (FVA) are now familiar valuation adjustments made to the value of a portfolio of derivatives to account for credit risks and funding costs. However, recent changes in the regulatory regime and the increases in regulatory capital requirements has led many banks to include the cost of capital in derivative pricing. This paper formalises the addition of cost of capital by extending the Burgard-Kjaer (2013) semi-replication approach to C...

  4. Improved Design Methods for Robust Single- and Three-Phase ac-dc-ac Power Converters

    Qin, Zian

    proposed new active power decoupling method, the ripple power in the converter can be compensated in a more efficient and more compact way. Then, Chapter 5 changes the scope of the thesis to three-phase converters, and the nine-switch converter, as a reduced switch version of two three-phase full......-bridges connected back-to-back, is studied. Application criteria of the nine-switch converter are investigated for reducing the relatively high stress introduced by the less number of switches. In Chapter 6 a rotating speed controller design method is proposed for improving the thermal loading of the three...... to users. Their performances including cost, efficiency, reliability, and so on, therefore are more important concerns than they were. The objective of this thesis is to study and propose advanced design methods for robust ac-dc-ac converters, which are widely used interfaces in energy conversion...

  5. Measures for speed management.

    2009-01-01

    Measures for speed management are essential for limiting the negative effects of driving too fast and at inappropriate speeds. To begin with, safe and credible speed limits need to be determined. Dynamic and variable speed limits that take into account the current circumstances, such as weather cond

  6. Speeding or not speeding? When subjective assessment of safe, pleasurable and risky speeds determines speeding behaviour

    Florent Lheureux

    2012-01-01

    Full Text Available It is hypothesized that in a given situation speeding behaviour is determined by three subjective speed assessments: the speed perceived as the riskiest, the speed perceived as the safest, and the speed perceived as the most pleasurable. Specifically, if these assessments are high, drivers are expected to circulate faster. Such speed perceptions are also viewed as influenced by attitudes towards speed and speed limits. 177 car drivers, included 102 men and 75 women between 18 and 72 years (M = 43, SD = 21 and with a mean driving experience of 22 years (SD = 19, answered to a questionnaire about their attitudes towards speed and speed limits, the speeds they considered as the riskiest, the safest, and the most pleasurable in three different contexts, as well as their usual speed. Data analyses (ANOVA and path analyses confirmed the influence of the three types of speed assessment on the usual speed and that the influence of attitudes on this behaviour is mediated by these three assessments. Results suggest that not only a change in attitudes and beliefs is desirable, but a concrete specification (e.g., 100 Km/h of speeds perceived as safe, pleasurable and risky is also needed in order to reduce speeding behaviour.

  7. Superconducting ac cable

    The components of a superconducting 110 kV ac cable for power ratings >= 2000 MVA have been developed. The cable design especially considered was of the semiflexible type, with a rigid cryogenic envelope and flexible hollow coaxial cable cores pulled into the former. The cable core consists of spirally wound Nb-Al composite wires and a HDPE-tape wrapped electrical insulation. A 35 m long single phase test cable with full load terminations for 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of our cable design. (orig.)

  8. High performance AC drives

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  9. Touch Screen based Speed Control of Single Phase Induction Motor

    S. Mallika

    2010-12-01

    Full Text Available This paper gives a brief idea of touch screen technology and its interfacing with a controller to control the speed of single phase induction motor. Here touch screen technology and Programmable System on Chip (PSOC microcontroller concept is utilized which is less spaceconsumption and easy to design. The aim of this paper is to have remote sensing and speed control of an AC motor.

  10. On the Application of TLS Techniques to AC Electrical Drives

    M. Cirrincione

    2005-03-01

    Full Text Available This paper deals with the application of a new neuron, the TLS EXIN neuron, to AC induction motor drives. In particular, it addresses two important subjects of AC induction motor drives: the on-line estimation of the electrical parameters of the machine and the speed estimation in sensorless drives. On this basis, this work summarizes the parameter estimation and sensorless techniques already developed by the authors over these last few years, all based on the TLS EXIN. With regard to sensorless, two techniques are proposed: one based on the MRAS and the other based on the full-order Luenberger observer. The work show some of the most significant results obtained by the authors in these fields and stresses the important potentiality of this new neural technique in AC induction machine drives.

  11. Sustainable urban regime adjustments

    Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten;

    2013-01-01

    The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

  12. Auto Adjusting Astronomical Telescope

    Rohit R. Ghalsasi; Prof. N. D. Dhoot

    2014-01-01

    Astronomical telescope is powerful and basic tool for star or celestial observation. Here we proposed integrated system using Raspberry Pi for auto adjusting astronomical telescope. This integrated circuit helps to control stellar monitoring, stellar targeting, and tracking functions of telescope. Astro compass gives the direction of the celestial objects.

  13. Adjustments and Depression

    Full Text Available ... 7309 ☰ Living with Paralysis Get Support Get Involved Research Events Blog & Forum About Us Donate Living with Paralysis > Newly paralyzed > How do I deal with depression and adjustment to my SCI? How do I deal with depression and ...

  14. Auto Adjusting Astronomical Telescope

    Rohit R. Ghalsasi

    2014-04-01

    Full Text Available Astronomical telescope is powerful and basic tool for star or celestial observation. Here we proposed integrated system using Raspberry Pi for auto adjusting astronomical telescope. This integrated circuit helps to control stellar monitoring, stellar targeting, and tracking functions of telescope. Astro compass gives the direction of the celestial objects.

  15. Kinematic synthesis of adjustable robotic mechanisms

    Chuenchom, Thatchai

    1993-01-01

    Conventional hard automation, such as a linkage-based or a cam-driven system, provides high speed capability and repeatability but not the flexibility required in many industrial applications. The conventional mechanisms, that are typically single-degree-of-freedom systems, are being increasingly replaced by multi-degree-of-freedom multi-actuators driven by logic controllers. Although this new trend in sophistication provides greatly enhanced flexibility, there are many instances where the flexibility needs are exaggerated and the associated complexity is unnecessary. Traditional mechanism-based hard automation, on the other hand, neither can fulfill multi-task requirements nor are cost-effective mainly due to lack of methods and tools to design-in flexibility. This dissertation attempts to bridge this technological gap by developing Adjustable Robotic Mechanisms (ARM's) or 'programmable mechanisms' as a middle ground between high speed hard automation and expensive serial jointed-arm robots. This research introduces the concept of adjustable robotic mechanisms towards cost-effective manufacturing automation. A generalized analytical synthesis technique has been developed to support the computational design of ARM's that lays the theoretical foundation for synthesis of adjustable mechanisms. The synthesis method developed in this dissertation, called generalized adjustable dyad and triad synthesis, advances the well-known Burmester theory in kinematics to a new level. While this method provides planar solutions, a novel patented scheme is utilized for converting prescribed three-dimensional motion specifications into sets of planar projections. This provides an analytical and a computational tool for designing adjustable mechanisms that satisfy multiple sets of three-dimensional motion specifications. Several design issues were addressed, including adjustable parameter identification, branching defect, and mechanical errors. An efficient mathematical scheme for

  16. The Design of Sport Bicycle Speed Odometer

    Dongbing Liu

    2013-04-01

    Full Text Available As bicycle sport equipment, a sport bike needs a speed and distance measuring device, due to the characteristic of road cycling, thereby mastering the state of motion. According to external conditions such as temperature, wind speed, the bike can make the appropriate adjustment to achieve the best movement effect. The bicycle speed odometer is a major accessibility tool that satisfies with needs of the people with fast development. This study elaborated a bike speed odometer design based on Hall element, taking AT89C52 single chip as the core, measuring speed with A44E Hall sensor, to finish the bike mileage/speed measurement and statistics by displaying bike mileage and speed in real time. By using the Hall elements, the hardware of speed odometer input the number of pulse of per circle into the single-chip computer system. Then the signal processed by the single-chip computer displays. The software is programmed with assembly language and modular design idea. The design of the hardware circuit is simple and the subroutine has universal property, which fully meet the design requirements and possess a wide range of application and dissemination value.

  17. Ac Hybrid Charge Controller

    Shalini S. Durgam

    2015-03-01

    Full Text Available One of the primary needs for socio-economic development in any nation in the world is the provision of reliable electricity supply systems with lower carbon footprint levels. The purpose of this work is the development of a hybrid Power system that harnesses the renewable energy in sun and electricity to generate electricity. The working model can able to run on dual mode- solar and electricity. It can also be driven independently either by solar or electricity. The battery can be charge from solar panel (40W or by power supply. The household single phase A.C. power supply of 230V is converted into 12V D.C. using step down transformer and rectifying circuit. The working model can achieve energy saving, low carbon emission, environmental protection for the upcoming future of human life.

  18. Control of Adjustable Compliant Actuators

    Berno J.E. Misgeld

    2014-05-01

    Full Text Available Adjustable compliance or variable stiffness actuators comprise an additional element to elastically decouple the actuator from the load and are increasingly applied to human-centered robotic systems. The advantages of such actuators are of paramount importance in rehabilitation robotics, where requirements demand safe interaction between the therapy system and the patient. Compliant actuator systems enable the minimization of large contact forces arising, for example, from muscular spasticity and have the ability to periodically store and release energy in cyclic movements. In order to overcome the loss of bandwidth introduced by the elastic element and to guarantee a higher range in force/torque generation, new actuator designs consider variable or nonlinear stiffness elements, respectively. These components cannot only be adapted to the walking speed or the patient condition, but also entail additional challenges for feedback control. This paper introduces a novel design method for an impedance-based controller that fulfills the control objectives and compares the performance and robustness to a classical cascaded control approach. The new procedure is developed using a non-standard positive-real Η2 controller design and is applied to a loop-shaping approach. Robust norm optimal controllers are designed with regard to the passivity of the actuator load-impedance transfer function and the servo control problem. Classical cascaded and positive-real Η2 controller designs are validated and compared in simulations and in a test bench using a passive elastic element of varying stiffness.

  19. Exploration adjustment by ant colonies.

    Doran, Carolina; Stumpe, Martin C; Sendova-Franks, Ana; Franks, Nigel R

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  20. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    Gallegos-Lopez, Gabriel; Nagashima, James M.; Perisic, Milun; Hiti, Silva

    2012-06-05

    A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.

  1. Physicians' adjustment to retirement.

    Virshup, B; Coombs, R H

    1993-01-01

    We address the questions, How do physicians adjust to and enjoy their retirement? What factors contribute to the well-being of retired physicians? A 60-item questionnaire mailed to 238 retired physicians in Los Angeles County with a 41.6% response rate assessed health, standard of living, relationships, activities, emotional difficulties, and general enjoyment. Health often improved after retirement, as did relationships with spouses and children. Standard of living was comfortable or better ...

  2. Credit Valuation Adjustment

    Hoffman, Frederick

    2011-01-01

    Credit risk has become a topical issue since the 2007 Credit Crisis, particularly for its impact on the valuation of OTC derivatives. This becomes critical when the credit risk of entities involved in a contract either as underlying or counterparty become highly correlated as is the case during macroeconomic shocks. It impacts the valuation of such contracts through an additional term, the credit valuation adjustment (CVA). This can become large with such correlation. This thesis outlines the...

  3. Adjustable Autonomy Testbed

    Malin, Jane T.; Schrenkenghost, Debra K.

    2001-01-01

    The Adjustable Autonomy Testbed (AAT) is a simulation-based testbed located in the Intelligent Systems Laboratory in the Automation, Robotics and Simulation Division at NASA Johnson Space Center. The purpose of the testbed is to support evaluation and validation of prototypes of adjustable autonomous agent software for control and fault management for complex systems. The AA T project has developed prototype adjustable autonomous agent software and human interfaces for cooperative fault management. This software builds on current autonomous agent technology by altering the architecture, components and interfaces for effective teamwork between autonomous systems and human experts. Autonomous agents include a planner, flexible executive, low level control and deductive model-based fault isolation. Adjustable autonomy is intended to increase the flexibility and effectiveness of fault management with an autonomous system. The test domain for this work is control of advanced life support systems for habitats for planetary exploration. The CONFIG hybrid discrete event simulation environment provides flexible and dynamically reconfigurable models of the behavior of components and fluids in the life support systems. Both discrete event and continuous (discrete time) simulation are supported, and flows and pressures are computed globally. This provides fast dynamic simulations of interacting hardware systems in closed loops that can be reconfigured during operations scenarios, producing complex cascading effects of operations and failures. Current object-oriented model libraries support modeling of fluid systems, and models have been developed of physico-chemical and biological subsystems for processing advanced life support gases. In FY01, water recovery system models will be developed.

  4. AcEST: BP920072 [AcEST

    Full Text Available YMU001_000132_F11 525 Adiantum capillus-veneris mRNA. clone: YMU001_000132_F11. BP920072 - Show ... YGMYGEGEKALETFADMEKSGIVPDSVVFIAII 617 Query: 139 NACSR SCLFHECHSYFEAMSTHHGIVPCLEHHSCVV 32 ACS S L E + FE M ... KLMTRDVVSWNTLIAGYAQVGQNEGLFCTFSDMLGQRVKPDLITFVIVLNACSR ... 125 VF+ + +D VSWN++I+GY Q G F M+ + D IT++++++ +R S ... YGVHGYGKKAIQIFEEMLANGASP 384 Query: 166 DLITFVIVLNACSR SCLFHECHSYFEAMSTHHGIVPCLEHHSCVV 32 +TFV VL ACS L E ... KLMTRDVVSWNTLIAGYAQVGQNEGLFCTFSDMLGQRVKPDLITFVIVLNACSR S 122 +VFDK R + WN L G E + + M V+ D T+ VL AC S Sbjc ...

  5. SPEED COMPLIANCE IN FREEWAY VARIABLE SPEED LIMIT SYSTEM – CASE STUDY OF THE PRAGUE CITY RING

    Michał MATOWICKI

    2016-03-01

    Full Text Available Many previous studies have confirmed the strong relationship between speed compliance and the frequency and severity of traffic accidents. Variable speed limit (VSL system as a measure to improve traffic safety enables the freeway system to change its posted speed limit based on various traffic and environmental conditions. Such system helps drivers to recognize the upcoming events, to adjust their driving style and in such way to address speed variation of the traffic flow. This is called speed harmonization. Although many studies researching the effect of VSL system on the traffic stream can be found, there are only few addressing its influence on the drivers behavior, particularly focusing on their tolerance limit and compliance, which has crucial meaning for future design of controlling algorithms. This study was prepared to inspect this grey area by studying the data from the VSL system at Prague city ring, describing the influence of the highway management system and its influence on drivers.

  6. A speed auto-adaptable system for high speed inspection of rail-track defects

    Ge, Jia; Luo, Yunhan; Zhang, Jun; Guo, Long; Sun, Liang; Chen, Zhe

    2012-11-01

    High quality images play a key role in inspecting surface defect of rail track. However, image distortion is frequently occurred in traditional detection systems in which exposure frequency of camera are fixed as constant. The system studied in this paper improves traditional systems by combining a speed auto-adaptable (SAA) system, to adjust proper exposure frequency and uniform image quality all the time according to vehicle riding speed. The system mainly consists of a high-speed external controlled camera, a rotary encoder and a signal processing card, with this system, performance in avoiding image distortion both in laboratory test and practical application can be achieved with minimum detection precision of 0.2 mm at relative low speed and theoretically maximum detection speed of approximate 489 km/h.

  7. Adjustment Criterion and Algorithm in Adjustment Model with Uncertain

    SONG Yingchun

    2015-02-01

    Full Text Available Uncertainty often exists in the process of obtaining measurement data, which affects the reliability of parameter estimation. This paper establishes a new adjustment model in which uncertainty is incorporated into the function model as a parameter. A new adjustment criterion and its iterative algorithm are given based on uncertainty propagation law in the residual error, in which the maximum possible uncertainty is minimized. This paper also analyzes, with examples, the different adjustment criteria and features of optimal solutions about the least-squares adjustment, the uncertainty adjustment and total least-squares adjustment. Existing error theory is extended with new observational data processing method about uncertainty.

  8. Online optimal flux-weakening control of permanent-magnet brushless AC drives

    Zhu, Z.Q.; Chen, Y. S.; Howe, D.

    2000-01-01

    An enhanced online optimal control strategy, which maximizes the flux-weakening performance of a brushless AC motor, is described, and applied to motors having different rotor topologies: interior (radial or circumferential), inset, and surface-mounted magnet. It enables the maximum inherent power capability of a brushless AC motor to be achieved independent of any variation in its parameters, and facilitates maximum efficiency over the entire speed range. It also results in good transient dy...

  9. System and method for motor speed estimation of an electric motor

    Lu, Bin; Yan, Ting; Luebke, Charles John; Sharma, Santosh Kumar

    2012-06-19

    A system and method for a motor management system includes a computer readable storage medium and a processing unit. The processing unit configured to determine a voltage value of a voltage input to an alternating current (AC) motor, determine a frequency value of at least one of a voltage input and a current input to the AC motor, determine a load value from the AC motor, and access a set of motor nameplate data, where the set of motor nameplate data includes a rated power, a rated speed, a rated frequency, and a rated voltage of the AC motor. The processing unit is also configured to estimate a motor speed based on the voltage value, the frequency value, the load value, and the set of nameplate data and also store the motor speed on the computer readable storage medium.

  10. Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

    Peak, S. C.

    1982-01-01

    An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

  11. AcEST: DK950147 [AcEST

    Full Text Available TST38A01NGRL0007_O05 706 Adiantum capillus-veneris mRNA. clone: TST38A01NGRL0007_O05. 5' end seq ... _MEDTR Peptidase, trypsin-like serine and cysteine proteases ... OS=Medicago truncatula GN=MtrDRAFT_AC149576g3v2 PE ... _MEDTR Peptidase, trypsin-like serine and cysteine proteases ... (Fragment) OS=Medicago truncatula GN=MtrDRAFT_AC14 ...

  12. AcEST: DK959344 [AcEST

    Full Text Available TST39A01NGRL0004_G23 714 Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0004_G23. 5' end seq ... _MEDTR Peptidase, trypsin-like serine and cysteine proteases ... OS=Medicago truncatula GN=MtrDRAFT_AC149576g3v2 PE ... _MEDTR Peptidase, trypsin-like serine and cysteine proteases ... (Fragment) OS=Medicago truncatula GN=MtrDRAFT_AC14 ...

  13. AcEST: DK949716 [AcEST

    Full Text Available TST38A01NGRL0006_L20 613 Adiantum capillus-veneris mRNA. clone: TST38A01NGRL0006_L20. 5' end seq ... _MEDTR Peptidase, trypsin-like serine and cysteine proteases ... OS=Medicago truncatula GN=MtrDRAFT_AC149576g3v2 PE ... _MEDTR Peptidase, trypsin-like serine and cysteine proteases ... (Fragment) OS=Medicago truncatula GN=MtrDRAFT_AC14 ...

  14. AcEST: BP920905 [AcEST

    Full Text Available EM + + D ++S L AC Sbjct: 374 NSAYKLFERMPKKNVVAWNAIISGYSQHGHPHEALALFIEMQAQGIKPDSFAIVSVLPAC 433 Query: 71 SHSSTLNDGKLIHFYILMNNFE...EM++ ++ + V + S L +C Sbjct: 255 SSERIFEKIAKKNAVSWTAMISSYNRGEFSEKALRSFSEMIKSGIEPNLVTLYSVLSSCG 314 Query: 68 HSSTLNDGKLIHFYILMNNFE...VVVMSCLKACS 69 ++ +F RRD VTW A+I GYA HG E A+ LF+ M+ EN+ + V +S L+AC+ Sbjct: 656 DSRLMFEKSLRRDFVTWNAMICGYAHHGKGEEAIQLFERMILEN...ELEKMHNKRLQEMCVSWNSIISGYVMKEQSEDAQMLFTRMME 596 Query: 122 ENVDTDGVVVMSCLKACSHSSTLNDGKLIHFYILMNNFE ...FCEADT-NVITWNAMIASYVHCEQSEKAIALFDRMVSENFKPSSITLVTLLMAC 543 Query: 71 SHSSTLNDGKLIHFYILMNNFEL 3 ++ +L G++

  15. Speed-up electric railways. Denki tetsudo no kosokuka

    Yasukawa, S.; Ito, J. (Railway Technical Research Institute, Tokyo (Japan))

    1993-04-20

    Explanation was made of speed heightening tendency of electric rail transport in Japan and Europe. The electric rail transport can transport a large quantity with a high safety and largely contribute particularly to the energy saving and solution of environmental problems. Introduction was made of Japanese superexpress lines, French TGV network, and German and Italian high speed railroads. DC motor has been conventionally used to strengthen the output as required by the speed heightening. Because the commutator and dynamic braking resistor are limited in size enlarging and weight increasing as required by a further speed heightening, the DC motor is being replaced by the AC motor or synchronous motor without commutators for the driving. For the coach weight lightening, design is made by lightening the bogie weight, compatibly with maintaining the running stability, and using the aluminum alloy for the body. The air resistance is proportional to the speed squared and therefore, particularly important for the high speed train. Progress is made in taking measures against the noise and vibration (due to dislocation, spark and aerodynamic force) under a stable power collecting performance through pantograph hardly coming off the overhead line. Pertaining to the ground facilities to satisfy the speed heightening, also mentioned were AC generation system which can supply a large electric energy, overhead wiring system, and ATC and other signal maintaining system. 31 refs., 10 figs., 2 tabs.

  16. AC drives for industrial plants. Plant kudoyo AC drive sochi

    Miyazaki, M.; Shibata, M.; Yamada, S. (Toshiba Corp., Tokyo (Japan))

    1992-08-01

    Features and product series of AC drives for industrial plants were outlined. Configurations and features of various types of AC drives were briefly discussed which are put into market to meet various requirements for industrial plants and wide ranges of output voltage and capacity. The following product series were outlined; the power bipolar transistor inverter for 3.5-600 kVA in output capacity, IGBT inverter for AC 400 V in output voltage and 1,000 kVA or less, GTO inverter for AC 600 V and 700-2,000 kVA, and cycloconverter for AC 1,000-3,000 V and 1,000 kW-20 MW. The following subjects were outlined as current technical trends of AC drives for industrial plants; increasing in capacity of voltage-source PWM inverters, downsizing of converters through highly efficient cooling and highly dense mounting, spreading of sensorless vector controls, and development of high-voltage large-capacity PWM inverters. 6 figs., 2 tabs.

  17. Jordan Adjusted Human Development

    Ababsa, Myriam

    2014-01-01

    Jordan Human Development Index (HDI) and Adjusted Human Development Index (IHDI) In 1990, the United Nations Development Programme designed a Human Development Index composed of life expectancy at birth, level of education and gross domestic product (GDP) per capita. In 2011, the UNDP ranked Jordan 95th out of 187 countries with a human development index of 0.698, up from 0.591 in 1990, making it the leading medium-range country for human development (fig. VIII.1). In 2010, the inequality adj...

  18. Continuously adjustable Pulfrich spectacles

    Jacobs, Ken; Karpf, Ron

    2011-03-01

    A number of Pulfrich 3-D movies and TV shows have been produced, but the standard implementation has inherent drawbacks. The movie and TV industries have correctly concluded that the standard Pulfrich 3-D implementation is not a useful 3-D technique. Continuously Adjustable Pulfrich Spectacles (CAPS) is a new implementation of the Pulfrich effect that allows any scene containing movement in a standard 2-D movie, which are most scenes, to be optionally viewed in 3-D using inexpensive viewing specs. Recent scientific results in the fields of human perception, optoelectronics, video compression and video format conversion are translated into a new implementation of Pulfrich 3- D. CAPS uses these results to continuously adjust to the movie so that the viewing spectacles always conform to the optical density that optimizes the Pulfrich stereoscopic illusion. CAPS instantly provides 3-D immersion to any moving scene in any 2-D movie. Without the glasses, the movie will appear as a normal 2-D image. CAPS work on any viewing device, and with any distribution medium. CAPS is appropriate for viewing Internet streamed movies in 3-D.

  19. The Design of Fiscal Adjustments

    Alesina, Alberto Francesco; Ardagna, Silvia

    2013-01-01

    This paper offers three results. First, in line with the previous literature, we confirm that fiscal adjustments based mostly on the spending side are less likely to be reversed. Second, spending based fiscal adjustments have caused smaller recessions than tax based fiscal adjustments. Finally, certain combinations of policies have made it possible for spending based fiscal adjustments to be associated with growth in the economy even on impact rather than with a recession. Thus, expansionary ...

  20. Speed and income

    Fosgerau, Mogens

    2005-01-01

    The relationship between speed and income is established in a microeconomic model focusing on the trade-off between travel time and the risk of receiving a penalty for exceeding the speed limit. This is used to determine when a rational driver will choose to exceed the speed limit. The relationship...... between speed and income is found again in the empirical analysis of a cross-sectional dataset comprising 60,000 observations of car trips. This is used to perform regressions of speed on income, distance travelled, and a number of controls. The results are clearly statistically significant and indicate...... an average income elasticity of speed of 0.02; it is smaller at short distances and about twice as large at the longest distance investigated of 200 km....

  1. SPEED CONTROL OF DC MOTOR WITH PIC 16F877

    ÇOLAK, İlhami; Ramazan BAYINDIR

    2005-01-01

    In this study, a PI controlled separately excited direct current (DC) motor speed has been controlled using PIC 16F877 controller. In the PIC 16F877 programming as a PI controller, the speed of the motor is expected to follow the reference speed. Speed of the motor is measured by a tacho generator and then, the voltage applied to the motor is adjusted by a semiconductor power switch using pulse width modulation (PWM) technique. Drive circuit was tested with 0.9 kW DC motor. Experimental resul...

  2. SPEED CONTROL OF DC MOTOR WITH PIC 16F877

    İlhami ÇOLAK

    2005-02-01

    Full Text Available In this study, a PI controlled separately excited direct current (DC motor speed has been controlled using PIC 16F877 controller. In the PIC 16F877 programming as a PI controller, the speed of the motor is expected to follow the reference speed. Speed of the motor is measured by a tacho generator and then, the voltage applied to the motor is adjusted by a semiconductor power switch using pulse width modulation (PWM technique. Drive circuit was tested with 0.9 kW DC motor. Experimental results show that the drive circuit developed is very simple, useful, sensible, economical and flexible to apply for different applications.

  3. Technical Document for Price Adjustment

    Zheng Tian; Mulugeta Kahsai; Randall Jackson

    2014-01-01

    This document presents the basis for the price adjustment mechanisms in a time series IO model. The essentials of the price adjustment and price change propagation algorithms are presented, along with a matrix permutation algorithm that facilitates the implementation of the price adjustment mechanism. The Matlab function is provided.

  4. 46 CFR 154.1864 - Vessel speed within speed reduction.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vessel speed within speed reduction. 154.1864 Section... Vessel speed within speed reduction. The master shall ensure that the speed of the vessel is not greater than the posted speed reduction....

  5. Modelling ac ripple currents in HTS coated conductors

    Xu, Zhihan; Grilli, Francesco

    2015-10-01

    Dc transmission using high temperature superconducting (HTS) coated conductors (CCs) offers a promising solution to the globally growing demand for effective, reliable and economic transmission of green energy up to the gigawatt level over very long distances. The credible estimation of the losses and thereby the heat dissipation involved, where ac ripples (introduced in rectification/ac-dc conversion) are viewed as a potential source of notable contribution, is highly essential for the rational design of practical HTS dc transmission cables and corresponding cryogenic systems to fulfil this demand. Here we report a targeted modelling study into the ac losses in a HTS CC subject to dc and ac ripple currents simultaneously, by solving Maxwell’s equations using the finite element method (FEM) in the commercial software package COMSOL. It is observed that the instantaneous loss exhibits only one peak per cycle in the HTS CC subject to sinusoidal ripples, given that the amplitude of the ac ripples is smaller than approximately 20% of that of the dc current. This is a distinct contrast to the usual observation of two peaks per cycle in a HTS CC subject to ac currents only. The unique mechanism is also revealed, which is directly associated with the finding that, around any local minima of the applied ac ripples, the critical state of -J c is never reached at the edges of the HTS CC, as it should be according to the Bean model. When running further into the longer term, it is discovered that the ac ripple loss of the HTS CC in full-wave rectification decays monotonically, at a speed which is found to be insensitive to the frequency of the applied ripples within our targeted situations, to a relatively low level of approximately 1.38 × 10-4 W m-1 in around 1.7 s. Comparison between this level and other typical loss contributions in a HTS dc cable implies that ac ripple currents in HTS CCs should only be considered as a minor source of dissipation in superconducting dc

  6. Adjusting to the Emergent

    Revsbæk, Line

    In her doctoral thesis Line Revsbaek explores newcomer innovation related to organizational entry processes in a changing organization. She introduces process philosophy and complexity theory to research on organizational socialization and newcomer innovation. The study challenges assumptions...... in standardized induction programs where newcomers are cast in roles as insecure novices needing to be “taught the ropes” of the organizational culture. Linked with this, it is suggested that the prevailing dichotomy of ‘newcomer assimilation’ versus ‘organizational accommodation’ is replaced with a notion...... of ‘adjusting to the emergent’. Newcomer innovation is portrayed as carrying a variety of possible significations, such as unintentional innovation effects of newcomer’s proactive self-socializing behavior; an inspirational basis for designing innovation-generating employee induction; ‘resonant instances...

  7. Metric adjusted skew information

    Hansen, Frank

    2008-01-01

    We extend the concept of Wigner-Yanase-Dyson skew information to something we call "metric adjusted skew information" (of a state with respect to a conserved observable). This "skew information" is intended to be a non-negative quantity bounded by the variance (of an observable in a state) that...... vanishes for observables commuting with the state. We show that the skew information is a convex function on the manifold of states. It also satisfies other requirements, proposed by Wigner and Yanase, for an effective measure-of-information content of a state relative to a conserved observable. We...... establish a connection between the geometrical formulation of quantum statistics as proposed by Chentsov and Morozova and measures of quantum information as introduced by Wigner and Yanase and extended in this article. We show that the set of normalized Morozova-Chentsov functions describing the possible...

  8. Performance Analysis of Phase Controlled Unidirectional and Bidirectional AC Voltage Controllers

    Abdul Sattar Larik

    2011-01-01

    Full Text Available AC voltage controllers are used to vary the output ac voltage from a fixed ac input source. They are also commonly called ac voltage regulators or ac choppers. The output voltage is either controlled by PAC (Phase Angle Control method or on-off control method. Due to various advantages of ac voltage controllers, such as high efficiency, simplicity, low cost and ability to control large amount of power they efficiently control the speed of ac motors, light dimming and industrial heating, etc. These converters are variable structure systems and generate harmonics during the operation which will affect the power quality when connected to system network. During the last couple of years, a number of new semiconductor devices and various power electronic converters has been introduced. Accordingly the subject of harmonics and its problems are of great concern to power industry and customers. In this research work, initially the simulation models of single phase unidirectional and bidirectional ac voltage controllers were developed by using MATLAB software. The harmonics of these models are investigated by simulation. In the end, the harmonics were also analyzed experimentally. The simulated as well as experimental results are presented.

  9. Adjustment Behaviours of Dividend Payouts in G7 Countries: A Different Look

    Joshua Seungwook Bahng

    2011-10-01

    Full Text Available The topic of the dividend adjustment behaviours of firms in G7 countries was analysed in this study. After dividing the entire sample of firms into countries and separating listed, delisted, and unlisted firms by their listing type, we investigated the question using quantile regressions. Our analyses provided the following results. First, payout ratios showed decreasing tendencies irrespective of both country origin and listing types. Second, the speeds of dividend adjustment in Japan and Italy were estimated to be the fastest by quantile, whereas that of Canadian firms was estimated to be the slowest. Third, when the same issue was examined for listing types, unlisted firms showed the fastest speed of adjustment. In general, the estimated curves for both the speed of adjustment and the required time for partial adjustment were found to be cross-sectionally unstable and nonlinear with respect to dividend levels.

  10. A Dynamic Flexible Partial-Adjustment Model of International Diffusion of the Internet

    Lee, Minkyu; Heshmati, Almas

    2006-01-01

    The paper introduces a dynamic, flexible partial-adjustment model and uses it to analyze the diffusion of Internet connectivity. It specifies and estimates desired levels of Internet diffusion and the speed at which countries achieve the target levels. The target levels and speed of adjustment are both country and time specific. Factors affecting Internet diffusion across countries are identified, and, using nonlinear least squares, the Gompertz growth model is generalized and estimated using...

  11. Speed enforcement in Norway

    Elvik, Rune

    2015-01-01

    This paper probes the relationship between changes in the risk of apprehension for speeding in Norway and changes in the amount of speeding. The paper is based on a game-theoretic model of how the rate of violations and the amount of enforcement is determined by the interaction between drivers and...

  12. More Than Just Speed

    2011-01-01

    The 1,318-km Beijing-Shanghai High-Speed Railway will finally come into operation at the end of June.Since construction began three years ago,the speedy railway has grabbed worldwide attention because of its design as the world’s longest and fastesthigh-speed rail line utilizing the most advanced technology.

  13. Adjustable drives boost nuclear plant reliability

    A new reactor recirculation control (RRC) adjustable-speed drive (ASD) and digital control system at the Washington Nuclear Plant 2 (WNP-2), Hanford, Wash., has improved plant reliability. Installed this year, the system also will lower plant maintenance costs and reduce personnel radiation doses during maintenance, since the new system has less equipment in high-radiation areas than its predecessor. Advances in power electronics have improved the reliability of adjustable-speed drives for large induction motors. Large ASDs have been used in gas, oil, and coal-fired plants since around 1984. Plants where these systems are installed have realized energy savings and operational improvements in precisely controlling process flow. They also have reduced motor maintenance by slowing the motors when full-power operation is not needed. WNP-2 is the first nuclear utility with a boiling-water reactor to change to digitally controlled reactor recirculation pumps. The new RRC system provides improved flow control and maneuverability, when operating the nuclear reactor at reduced power levels. It controls coolant flow through the reactor core to control power during normal operation. There are two pumps rated at 47,200 gallons per minute (gpm). Each is driven by a vertical, totally enclosed, air/water-cooled, three-phase induction motor. The motor is rated at 8,900 horsepower (hp) and 1,782 revolutions per minute (rpm) and is operated from a 6,600-volt, 60-hertz (Hz) electrical power supply. THe ASD and digital control system replaced a hydraulically operated flow control valve and analog control system for throttling pump output. The replacement also resulted in removing the low-frequency motor generator set used for startup and slow-speed operation. The flow control valve system required a shift from low to high frequency at minimum flow control valve position to prevent excess reactor power conditions from forming during pump shift. 6 refs., 2 figs

  14. Effectiveness of Motorcycle speed controlled by speed hump

    Pornsiri Urapa

    2014-09-01

    Full Text Available Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road.

  15. AcEST: BP915640 [AcEST

    Full Text Available YMU001_000074_A01 462 Adiantum capillus-veneris mRNA. clone: YMU001_000074_A01. BP915640 CL3685C ... y: 462 GPLILRACLVYMQGAPVGSLAEDGIVSAATGKDMEQSTVGFRLMLAKI IHRLIAAFKEVG 283 G IL+AC YM+G +GSL +D V ++VGF+LMLAK ... : 1032 GYYILKACDAYMKGYLIGSLTKDASVIDERSS-ANSTSVGFKLMLAKI APKLFSALSEVG 1090 Query: 282 AYCDAYE 262 A C+ ++ Sb ... uery: 453 ILRACLVYMQGAPVGSLAEDGIVSAATGKDMEQSTVGFRLMLAKI IHRLIAAFKEVGAYC 274 +L AC YM+G PVGS A G ST GF++ML+K ... ame = -1 Query: 423 GAPVGSLAEDGIVSAATGKDMEQSTVGFRLMLAKI I----HRLIAAFKEVGAYCD 271 G P+ L D +S GK + S RL + L+ ...

  16. AcEST: DK955197 [AcEST

    Full Text Available TST39A01NGRL0022_H07 532 Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0022_H07. 5' end seq ... KDEVTALPLLK 192 Query: 194 RFAFGIACELLMSRYEKEEQEMLEEPF TTMMKGILQLPIKLPGTRFSKAIVAANMLRARF 373 R+ F +AC+L S ... KDEVMALPLLK 192 Query: 194 RFAFGIACELLMSRYEKEEQEMLEEPF TTMMKGILQLPIKLPGTRFSKAIVAANMLRARF 373 R+ F +AC+L S ... KDEVKVLP 189 Query: 185 LMKRFAFGIACELLMSRYEKEEQEMLEEPF TTMMKGILQLPIKLPGTRFSKAIVAANMLR 364 L++ F IA L + +Q+ ... KDEATVLP 177 Query: 185 LMKRFAFGIACELLMSRYEKEEQEMLEEPF TTMMKGILQLPIKLPGTRFSKAIVAANMLR 364 L+K F +A L E+ QE ...

  17. Delay Adjusted Incidence Infographic

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  18. Near-optimal order-reduced control for A/C (air-conditioning) system of EVs (electric vehicles)

    This work is aimed to investigate the regulation problem for thermal comfortableness and propose control strategies for cabin environment of EVs (electric vehicles) by constructing a reduced-scale A/C (air-conditioning) system which mainly consists of two modules: ECB (environmental control box) and AHU (air-handling unit). Temperature and humidity in the ECB can be regulated by AHU via cooling, heating, mixing air streams and adjusting speed of fans. To synthesize the near-optimal controllers, the mathematical model for the system thermodynamics is developed by employing the equivalent lumped heat capacity approach, energy/mass conservation principle and the heat transfer theories. In addition, from the clustering pattern of system eigenvalues, the thermodynamics of the interested system can evidently be characterized by two-time-scale property. That is, the studied system can be decoupled into two subsystems, slow mode and fast mode, by singular perturbation technique. As to the optimal control strategies for EVs, by taking thermal comfortableness, humidity and energy consumption all into account, a series of optimal controllers is synthesized on the base of the order-reduced thermodynamic model. The feedback control loop for the experimental test rig is examined and realized by the aid of the control system development kit dSPACE DS1104 and the commercial software MATLAB/Simulink. To sum up, the intensive computer simulations and experimental results verify that the performance of the near-optimal order-reduced control law is almost as superior as that of standard LQR (Linear-Quadratic Regulator). - Highlights: • A reduced-scale test rig for A/C (air-conditioning) system to imitate the temperature/humidity of cabin in EV (electric vehicle) is constructed. • The non-linear thermodynamic model of A/C system can be decoupled by singular perturbation technique. • The temperature/humidity in cabin is regulated to the desired values by proposed optimal

  19. Nuclear structure of $^{231}$Ac

    Boutami, R; Mach, H; Kurcewicz, W; Fraile, L M; Gulda, K; Aas, A J; García-Raffi, L M; Løvhøiden, G; Martínez, T; Rubio, B; Taín, J L; Tengblad, O

    2008-01-01

    The low-energy structure of 231Ac has been investigated by means of gamma ray spectroscopy following the beta-decay of 231Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a mini-orange electron spectrometer. The decay scheme of 231Ra --> 231Ac has been constructed for the first time. The Advanced Time Delayed beta-gamma-gamma(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus.

  20. Proactive Adjustments of Response Strategies in the Stop-Signal Paradigm

    Verbruggen, Frederick; Logan, Gordon D.

    2009-01-01

    In the stop-signal paradigm, fast responses are harder to inhibit than slow responses, so subjects must balance speed is the go task with successful stopping in the stop task. In theory, subjects achieve this balance by adjusting response thresholds for the go task, making proactive adjustments in response to instructions that indicate that…

  1. AcEST: BP920800 [AcEST

    Full Text Available DLNLALQVHSRMVRFGFNAEVEACGALINMYGKCGKVLYAQRVFDDT 298 Query: 206 RQQDVISWNDIISACAQRGHGTEALENFSQMLHEGIVPNSMTFTSVMQA---CNSIEGG...G L +A S F ++ +D+ISW +I +Q EA+ F Sbjct: 217 SEKNEATSNCLINGYMGLGNLEQAESLFNQMPVKDIISWTTMIKGYSQNKRYREAIAVFY 276 Query: 119 QMLHEG...EKAWRIFDGVSCKNLPSWNAIITGCVQGGLLEEAIDLYRHMK 281 Query: 110 HEGIVPNSMTFTSVMQAC---NSIEGGR 36 + + PN +T +V+ AC +...N IIS AQ G +EA+E ++ M Sbjct: 383 DITIGNAVVVMYAKLGLVDSARAVFNWLPNTDVISWNTIISGYAQNGFASEAIEMYNIME 442 Query: 110 HEG...EIDLGEQIHSLSVKTGFESDMYVSGVLIDMYSKYGWLEKARRVLEML 406 Query: 206 RQQDVISWNDIISACAQRGHGTEALENFSQMLHEGIVPNSMTFTSVMQACNSIEGG

  2. AcEST: DK945549 [AcEST

    Full Text Available AGGCGATTTCATCTTTTCTGAGAACCCTGATTTTGTGATTGTGTAATTACA ACTGTGGAACAGAAGGATGAGAAGTCTACTGACACAACAAGATATCTCTGGAGAGGAGA...A AATTGAGAAGGTTTGAGTTCTCAACAATGGGCTATGAGGCAATAATGGGAAGGCACCGAT TGTGGGCTTGTATAGGTTTTGAC...LCTG 239 L++R+LRR + + ++ G AC+ DP +P PLC+G Sbjct: 108 LQQRELRRKLLADSGALNTNSVNGPRNWKACVQQDPSSRPGTPLCSG 154 >sp|A6UUY8|RNZ_META3...49 Tissue type young leaves Developmental stage sporophyte Contig ID CL454Contig1 Sequence GATGAGCGA...CCACCTGTGCAACCGTCAGCGCCTTTGTGCACTGGTG CAATGTCCTGTGGTTACCTTGTTTGGAATCTTAATTGTTCTCATGTAT

  3. AcEST: BP917632 [AcEST

    Full Text Available YMU001_000103_D10 554 Adiantum capillus-veneris mRNA. clone: YMU001_000103_D10. BP917632 - Show ... YSKCKIHQKALELLVLML 154 Query: 466 KDSLEPDEVTYLNVLKACARE EDLKV 543 +D++ P+ TY +VL++C D+++ Sbjct: 155 RDNVRPN ... 185 Query: 415 GHSDSS--KEALKLLTQMRKDSLEPDEVTYLNVLKACARE EDLK 540 + EA KL +M+ ++ PDE+ N++ AC R +++ Sbjct: 18 ...

  4. AcEST: DK961189 [AcEST

    Full Text Available OS=A... 127 7e-29 sp|Q94B08|GCP1_ARATH Germination-specific cysteine protease 1 OS... 125 2e-28 sp|P00785|AC...IRNSWGLNWGDSGYVKLQRNIDDPFGKCGIAMMPSYP 347 >sp|Q94B08|GCP1_ARATH Germination-specific cysteine protease 1 OS=

  5. AcEST: DK946687 [AcEST

    Full Text Available YMU02A01NGRL0013_G11 544 Adiantum capillus-veneris mRNA. clone: YMU02A01NGRL0013_G11. 5' end seq ... + G P+ TY+ + AC+ E Sbjct: 97 YSFNYMIRGLTNTWN-------DHEA ---ALSLYRRMKFSGLKPDKFTYNFVFIACAKLE 146 Query: 214 A ... Sbjct: 71 LIPKAVELGDFNYSSFLFSVTEEPNHYSFNYMIRGLTNTWNDHEA ALSLYRRMKFSGLKP 130 Query: 469 DGATFSCVLRACGNVGALDV ...

  6. AcEST: DK949372 [AcEST

    Full Text Available TST38A01NGRL0005_N02 627 Adiantum capillus-veneris mRNA. clone: TST38A01NGRL0005_N02. 5' end seq ... 363 DQLREKTC-GVDKFDDIVMACXXXXXXXXXXXXXXXXXXKARVHAYGVCD DPEYFYDYVQ 539 Q++EK G+ FDDIV+AC KA+VHA+ VCD DP+YFYD ... 264 QQVQEKKVPGITFFDDIVVACGSGGSIAGLSLGSYLSNLKAKVHAFAVCD DPDYFYDYTQ 323 Query: 540 GLLDGMNANIASRDIVNVIDAKGLG ...

  7. Adjustment computations spatial data analysis

    Ghilani, Charles D

    2011-01-01

    the complete guide to adjusting for measurement error-expanded and updated no measurement is ever exact. Adjustment Computations updates a classic, definitive text on surveying with the latest methodologies and tools for analyzing and adjusting errors with a focus on least squares adjustments, the most rigorous methodology available and the one on which accuracy standards for surveys are based. This extensively updated Fifth Edition shares new information on advances in modern software and GNSS-acquired data. Expanded sections offer a greater amount of computable problems and their worked solu

  8. Metric-adjusted skew information

    Liang, Cai; Hansen, Frank

    2010-01-01

    We give a truly elementary proof of the convexity of metric-adjusted skew information following an idea of Effros. We extend earlier results of weak forms of superadditivity to general metric-adjusted skew information. Recently, Luo and Zhang introduced the notion of semi-quantum states on a...... bipartite system and proved superadditivity of the Wigner-Yanase-Dyson skew informations for such states. We extend this result to the general metric-adjusted skew information. We finally show that a recently introduced extension to parameter values 1 < p = 2 of the WYD-information is a special case of...... (unbounded) metric-adjusted skew information....

  9. Dissecting the PPP Puzzle: The Unconventional Roles of Nominal Exchange Rate and Price Adjustments

    Yin-wong Cheung; Lai, Kon S.; Michael Bergman

    2003-01-01

    The conventional view, as expounded by sticky-price models, is that price adjustment determines the PPP reversion rate. This study examines the mechanism by which PPP deviations are corrected. Nominal exchange rate adjustment, not price adjustment, is shown to be the key engine governing the speed of PPP convergence. Moreover, nominal exchange rates are found to converge much more slowly than prices. With the reversion being driven primarily by nominal exchange rates, real exchange rates also...

  10. Dissecting the PPP Puzzle: The Unconventional Roles of Nominal Exchange Rate and Price Adjustment

    Cheung, Yin-Wong; Lai, Kon S.; BERGMAN, MICHAEL

    2003-01-01

    The conventional view, as expounded by sticky-price models, is that price adjustment determines the PPP reversion rate. This study examines the mechanism by which PPP deviations are corrected. Nominal exchange rate adjustment, not price adjustment, is shown to be the key engine governing the speed of PPP convergence. Moreover, nominal exchange rates are found to converge much more slowly than prices. With the reversion being driven primarily by nominal exchange rates, real exchange rates also...

  11. Management Practices and Financial Performance of Agricultural Cooperatives: A Partial Adjustment Model

    Azzam, Azzeddine M.; Turner, Michael S.

    1991-01-01

    This paper uses the Nerlovian partial adjustment model to test the hypothesis that the rate of a cooperative's adjustment to a desired financial position is partially determined by its management practices. The results indicate that management practices that are board responsibilities are not contributing to the speed of adjustment in reaching the desired financial performance, which is the responsibility of the board of directors. But management, when independently pursuing management's resp...

  12. The adjustment of financial ratios in the presence of soft budget constraints: evidence from Bulgaria.

    Konings, Josef

    2004-01-01

    This paper is the first to study the behaviour of financial ratios in an emerging economy of Central Europe. Using the entire population of company accounts in Bulgaria we find that for the financial ratios we considered, adjustment towards a target takes place but the speed of adjustment is lower than that for Western companies reported in earlier studies. Also, we find the adjustment of financial ratios in Bulgaria to be far slower in firms characterized by soft budget constraints, a widesp...

  13. Speeding up Transportation

    2007-01-01

    @@ 2007 was an excellent year for the transportation industry, marked by high speed railway transportation, development of the national expressway network and launch of the Chang'e lunar probe satellite.

  14. High speed data acquisition

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab

  15. High speed data acquisition

    Cooper, P.S.

    1997-07-01

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab.

  16. High-Speed Photography

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) copyright 1998 Society of Photo-Optical Instrumentation Engineers

  17. High-Speed Photography

    Paisley, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Schelev, M.Y. [General Physics Institute, Moscow (Russia)

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  18. Wind_Speeds_Master

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included wind speeds for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came from...

  19. Variable Speed Wind Turbine Based on Multiple Generators Drive-Train Configuration

    Deng, Fujin; Chen, Zhe

    2010-01-01

    A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine. A cascaded multilevel converter interface based on the MPMSGs is developed to synthesize a desired high ac sinusoidal output voltage, which could be directly connected to the grids. What is more, such arrangement has been made so that the output ac voltage having a selected phase angle difference among the stator w...

  20. High Speed Economy

    Vadim Dumitrascu; Roxana Arabela Dumitrascu

    2013-01-01

    The use of knowledge in business opens vast possibilities for the spectacular intensification of the rhythms of the processes of economic value creation. High speeds are a fundamental feature of the knowledge economy. The sources of high speeds in business are certain economic, technological and commercial processes with the nature of some positive feedbacks. What generates it is the organization of knowledge in the form of networks. The organizations competitiveness is marked by the ability ...

  1. Optimization of target speeds of high-speed railway trains for traction energy saving and transport efficiency improvement

    In the pursuit of higher operation speed at the passenger train services in China, the impacts of high-speed operation on energy consumption and transport efficiency are however not clearly identified. This research attempts to analyze the traction energy cost and transport operation time per 10,000 passenger-kilometers of high-speed railway (HSR) trains with a range of target speeds on certain HSR lines in China through a simulation approach. Having considered the effect of inter-stop transport distances, traction characteristics of HSR trains and gradients, curvatures, etc. of the rail lines, this study has deduced that the target speed of a HSR train for an inter-stop transport distance shorter than 100 km should be below 190 km/h from the perspectives of traction energy saving and transport efficiency improvement. Moreover, the study results also indicate that, unlike the actual HSR operation, the target speed should be dynamically adjusted according to the transport distances between stops if the transport capacity of the rail line is not extensively used. The exact target speed for each inter-stop transport distance shorter than 100 km should be further determined according to the traction characteristics of the train and the track geometry of the rail line. - Highlights: ► We simulate traction processes of different high-speed trains. ► We study trains' target speeds, energy costs and transport efficiencies. ► Short stop-spacings increase energy cost especially for high target speeds. ► Transport efficiency decreases with shortening stop-spacing for high target speeds. ► Target speed should be dynamically adjusted according to inter-stop distances.

  2. Police enforcement and driving speed.

    2008-01-01

    Speed limits are violated frequently in the Netherlands. As speed is an important factor in road crashes, the surveillance of driving speeds is one of the spearheads in the policy plans of the Dutch police. Different methods of speed enforcement have proved to be effective in reducing speed and cras

  3. Speed Control Of Induction Motor Using Dspic30f2023

    M. S. Aspalli

    2013-09-01

    Full Text Available AC motor drives are widely used to control the speed of conveyor systems, blower speeds, pump speeds, machine tool speeds and other applications that require variable speed with variable torque. The main aim of the work is to design and develop an electronic system that can be used to control the speed of a three phase induction motor.The speed of the three phase induction motor can be controlled by various methods. The stator frequency control is one of the simplest methods to control the speed of IM and the same method is employed.In the proposed scheme, dsPIC30F2023 controller is used to produce control signals for switches (IGBTs. It is a 44 pin IC. As compared to the PIC controller and DSP, dsPIC is cheaper and most reliable. The dsPIC DSC has the “heart” of a 16-bit MCU with robust peripherals and fast interrupt handling capability and the “brain” of a DSP that manages high computation activities, creating the optimum single chip solution for embedded system designs.

  4. Apuntes de Acústica

    Martín Domingo, Agustín

    2014-01-01

    Esta publicacion contiene unos apuntes para la parte de Acústica de las asignaturas de la ETSAM, junto con cierta cantidad de material adicional que excede el ámbito del curso. Aunque está lejos de ser completa y de estar libre de errores, el autor espera sea útil.

  5. SSTI Clark ACS Technology Demonstrations

    Freesland, Douglas

    1997-01-01

    SSTI Clark, one of two spacecraft built under NASA's Small Satellite Technology Initiative, includes seven ACS technology demonstrations. The technologies redefine the performance cost envelope, providing improved sensor and actuator performance at reduced costs. Six sensing technologies are being flown consisting of both hardware and algorithmic demonstrations: autonomous star tracker, hemispherical resonating gyro, GPS attitude determination, miniature horizon sensors, low cost course sun s...

  6. Energy saving in ac generators

    Nola, F. J.

    1980-01-01

    Circuit cuts no-load losses, without sacrificing full-load power. Phase-contro circuit includes gate-controlled semiconductor switch that cuts off applied voltage for most of ac cycle if generator idling. Switch "on" time increases when generator is in operation.

  7. Speed Control of Induction Motor using FOC Method

    Hafeezul Haq

    2015-03-01

    Full Text Available An increasing number of applications in high performing electrical drive systems use nowadays, squirrel-cage induction motors. This paper describes a simplified method for the speed control of a three phase AC drive using Proportional-Integral controller. The simulation results show that the step response of the model is very fast, steady and able to work in four quadrants, and robustness and high performance is achieved.

  8. How Fast Wages Adjust to Prices: A Multi Country Analysis

    Mohsen Bahmani-oskooee; Massoumeh Hajilee

    2011-01-01

    The adjustment of nominal wages to inflation has implications on the labor market as well as on other areas in economics. In this paper, we employ the Blanchard and Katz (1997, 1999) model of nominal wage determination and try to estimate the adjustment speed. By using the bounds testing approach for cointegration and error-correction modeling we distinguish the short run from the long run. The model is estimated for 29 countries using annual data over the period 1975-2006. We find that infla...

  9. Variance Adjusted Actor Critic Algorithms

    Tamar, Aviv; Mannor, Shie

    2013-01-01

    We present an actor-critic framework for MDPs where the objective is the variance-adjusted expected return. Our critic uses linear function approximation, and we extend the concept of compatible features to the variance-adjusted setting. We present an episodic actor-critic algorithm and show that it converges almost surely to a locally optimal point of the objective function.

  10. Mood Adjustment via Mass Communication.

    Knobloch, Silvia

    2003-01-01

    Proposes and experimentally tests mood adjustment approach, complementing mood management theory. Discusses how results regarding self-exposure across time show that patterns of popular music listening among a group of undergraduate students differ with initial mood and anticipation, lending support to mood adjustment hypotheses. Describes how…