WorldWideScience

Sample records for high speed operating

  1. Potential scenarios of concern for high speed rail operations

    Science.gov (United States)

    2011-03-16

    Currently, multiple operating authorities are proposing the : introduction of high-speed rail service in the United States. : While high-speed rail service shares a number of basic : principles with conventional-speed rail service, the operational : ...

  2. A High-Speed Train Operation Plan Inspection Simulation Model

    Directory of Open Access Journals (Sweden)

    Yang Rui

    2018-01-01

    Full Text Available We developed a train operation simulation tool to inspect a train operation plan. In applying an improved Petri Net, the train was regarded as a token, and the line and station were regarded as places, respectively, in accordance with the high-speed train operation characteristics and network function. Location change and running information transfer of the high-speed train were realized by customizing a variety of transitions. The model was built based on the concept of component combination, considering the random disturbance in the process of train running. The simulation framework can be generated quickly and the system operation can be completed according to the different test requirements and the required network data. We tested the simulation tool when used for the real-world Wuhan to Guangzhou high-speed line. The results showed that the proposed model can be developed, the simulation results basically coincide with the objective reality, and it can not only test the feasibility of the high-speed train operation plan, but also be used as a support model to develop the simulation platform with more capabilities.

  3. Generation of an Optimum High Speed High Accuracy Operational Amplifier.

    Science.gov (United States)

    1985-09-01

    certainly will have gains and emitter resistances that are not identical. In mono- lithic op-amps, it is highly desirable that all of the tran- sistors on a...external resistances ( a and K . altered). In general, w and Q are functions of a and K. p .p , "It is desirable to select these values such that the...220),OMEGA(220) COMPLEX HH,S,DENOM REAL K,ANUM c THE FOLLOWING ARE CONSTANTS TO BE UTILIZED:A01=>DC GAIN OF FIRST c OPAMP ;A02=>DC GAIN OF SECOND OPAMP

  4. Machining Chatter Analysis for High Speed Milling Operations

    Science.gov (United States)

    Sekar, M.; Kantharaj, I.; Amit Siddhappa, Savale

    2017-10-01

    Chatter in high speed milling is characterized by time delay differential equations (DDE). Since closed form solution exists only for simple cases, the governing non-linear DDEs of chatter problems are solved by various numerical methods. Custom codes to solve DDEs are tedious to build, implement and not error free and robust. On the other hand, software packages provide solution to DDEs, however they are not straight forward to implement. In this paper an easy way to solve DDE of chatter in milling is proposed and implemented with MATLAB. Time domain solution permits the study and model of non-linear effects of chatter vibration with ease. Time domain results are presented for various stable and unstable conditions of cut and compared with stability lobe diagrams.

  5. Premiere in high speed materials inter-operability

    Energy Technology Data Exchange (ETDEWEB)

    Brun, D.

    1995-07-01

    The Eurostar trains have been designed to meet the safety requirements of the Channel Tunnel. In particular, ti must be possible to remove the train from the tunnel in most fault scenarios. The train design is based upon an optimal capacity/price ratio. As far as the installation of electrical equipment is concerned (power supply, power conversion, motor units), the variety of track configurations is another consideration in addition to the questions of safety. The original solutions adopted give traction and braking performance that are satisfactory by comparison with the high-speed trains (TGV) in service on appropriate track, and the best possible for the British track. The trains are heavier and less powerful, but they are capable of getting out of the tunnel with only one motor out of three in service. (author). 6 figs.

  6. Dynamic Control of High-speed Train Following Operation

    Directory of Open Access Journals (Sweden)

    Deng Pan

    2014-08-01

    Full Text Available Both safety and efficiency should be considered in high-speed train following control. The real-time calculation of dynamic safety following distance is used by the following train to understand the quality of its own following behavior. A new velocity difference control law can help the following train to adjust its own behavior from a safe and efficient steady-following state to another one if the actual following distance is greater than the safe following distance. Meanwhile, the stopping control law would work for collision avoidance when the actual following distance is less than the safe following distance. The simulation shows that the dynamic control of actual inter-train distance can be well accomplished by the behavioral adjustment of the following train, and verifies the effectiveness and feasibility of our presented methods for train following control.

  7. The high-speed operation of single phase switched reluctance motor considering magnetic saturation

    Science.gov (United States)

    Ahn, Joonseon; Won, Sung Hong; Lee, Ju

    2006-04-01

    In the high-speed operation of SRM, the conventional pulse width modulation (PWM) drive method is not available because of the limitation of switching speed; therefore the single-pulse drive method is commonly employed. On the contrary, the use of the single-pulse drive method cannot avoid the overcurrent in the low-speed operation because of the insufficient back emf and the difficulty of duty control. With these reasons, the switching method is commonly changed from PWM at the low-speed operation to the single-pulse method at the high-speed operation. In the fan application, the required load torque increases as a square of the fan speed; it requires more current for the torque generation. Therefore at the mode transition between PWM and single-pulse drive, it is unavoidable that the phase current rapidly increases if the nonlinearity of inductance to the current is not considered. In this paper, by using finite element method (FEM) which is considered with the nonlinearity of the inductance with respect to the current, the speed of mode transition is calculated (18 000 rpm) and verified by the experiment.

  8. Investigating technical challenges and research needs related to shared corridors for high speed passenger and railroad freight operations.

    Science.gov (United States)

    2013-05-01

    The development of both incremental and dedicated high-speed rail lines in the United States poses a number of questions. Despite nearly 50 years of international experience in planning, designing, building and operating high-speed passenger infrastr...

  9. Providing wireless bandwidth for high-speed rail operations : final report.

    Science.gov (United States)

    2016-07-01

    This project examined the possibility of providing wireless communication for train control systems on American high-speed trains. In this : study, the key issue is that the frequencies allocated for rail operations in the U.S. and the frequencies us...

  10. ON EFFICIENT OPERATIONAL CONCEPT OF FUTURE HIGH-SPEED RAILWAY IN THE CZECH REPUBLIC

    Directory of Open Access Journals (Sweden)

    Michal Drábek

    2016-09-01

    Full Text Available The aim of this paper is to elaborate a layout of the first operational concept of Rapid Services with 1 hour system travel time between Praha and Brno. Two basic methods are used – Integrated Periodic Timetable (periodic rendezvous of all services in IPT-nodes and Operational Concept Economy Approach, as defined below by the author. In this paper, three recent high-speed railway concepts for the future so-called Rapid Services network of the Czech Republic are followed-up. The first one is an operational traffic planning study by Kalcík, Janoš et al. on behalf of Czech Ministry of Transport from 2010. The second one is the high-speed railway promoting book High Speed Rail Even in the Czech Republic by Šlegr et al. from 2012, with likely the most detailed concept of Rapid Services network. The third one is a paper on progress of the official spatial-technical studies for some future Czech high-speed lines by Šulc from 2014. The importance of achievement of 1 hour travel time between the largest agglomerations is briefly presented. The presented methodological approach, although soft and manager-oriented, comprises some firm principles: segmentation of high-speed train offer, so that more expensive rolling stock is not wasted by operation on long conventional line sections, consideration of system travel times for efficient rolling stock circuit, restriction of need for links from high-speed to conventional lines, and utilization of high-speed lines as a "rail highway". This approach is intended to be particularized iteratively, with every application. So, in this paper, first version of Operational Concept Economy Approach is introduced. The key idea is that passengers should be offered such travel times and service intervals (headways and such number of direct services, which are adequate to their potential demand, but as much synergistic effect as possible should be strived to be achieved for every proposed construction (new or

  11. Operational Influence on Thermal Behavior of High-Speed Helical Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Kilmain, Charles J.

    2006-01-01

    An experimental effort has been conducted on an aerospace-quality helical gear train to investigate the thermal behavior of the gear system as many important operational conditions were varied. Drive system performance measurements were made at varying speeds and loads (to 5,000 hp and 15,000 rpm). Also, an analytical effort was undertaken for comparison to the measured results. The influence of the various loss mechanisms from the analysis for this high speed helical gear train gearbox will be presented and compared to the experimental results.

  12. High speed rail trends, technologies and operational patterns: a comparison of established and emerging networks

    Directory of Open Access Journals (Sweden)

    Roberto PALACIN

    2014-10-01

    Full Text Available This paper is set within the framework of the RailNewcastle Summer School program 2014 run by Newcastle University (UK. It presents a short history of high speed rail describing its main design and operational characteristics. The focus of the paper is on assessing the two key distinct models emerging from this trend: the Japanese or Shinkansen model and the French or TGV model. The study then applies these two models to an emerging high speed network such as the planned corridors in California (U.S. to assess the extent of applicability and suitability of applying established high speed models to the Californian network. The results suggest that a suitable possibility would be to apply the French model for the operational aspects given the similarities in terms of geography, population distribution and distance. Implementing the lessons learned from the Japanese model in terms of construction and infrastructure design would be more suitable given the striking similarities in geological characteristics linked to the latent earthquake threat.

  13. Design and Operating Characteristics of High-Speed, Small-Bore Cylindrical-Roller Bearings

    Science.gov (United States)

    Pinel, Stanley, I.; Signer, Hans R.; Zaretsky, Erwin V.

    2000-01-01

    The computer program SHABERTH was used to analyze 35-mm-bore cylindrical roller bearings designed and manufactured for high-speed turbomachinery applications. Parametric tests of the bearings were conducted on a high-speed, high-temperature bearing tester and the results were compared with the computer predictions. Bearings with a channeled inner ring were lubricated through the inner ring, while bearings with a channeled outer ring were lubricated with oil jets. Tests were run with and without outer-ring cooling. The predicted bearing life decreased with increasing speed because of increased contact stresses caused by centrifugal load. Lower temperatures, less roller skidding, and lower power losses were obtained with channeled inner rings. Power losses calculated by the SHABERTH computer program correlated reasonably well with the test results. The Parker formula for XCAV (used in SHABERTH as a measure of oil volume in the bearing cavity) needed to be adjusted to reflect the prevailing operating conditions. The XCAV formula will need to be further refined to reflect roller bearing lubrication, ring design, cage design, and location of the cage-controlling land.

  14. Design and Operating Characteristics of High-Speed, Small-Bore, Angular-Contact Ball Bearings

    Science.gov (United States)

    Pinel, Stanley I.; Signer, Hans R.; Zaretsky, Erwin V.

    1998-01-01

    The computer program SHABERTH was used to analyze 35-mm-bore, angular-contact ball bearings designed and manufactured for high-speed turbomachinery applications. Parametric tests of the bearings were conducted on a high-speed, high-temperature bearing tester and were compared with the computer predictions. Four bearing and cage designs were studied. The bearings were lubricated either by jet lubrication or through the split inner ring with and without outer-ring cooling. The predicted bearing life decreased with increasing speed because of increased operating contact stresses caused by changes in contact angle and centrifugal load. For thrust loads only, the difference in calculated life for the 24 deg. and 30 deg. contact-angle bearings was insignificant. However, for combined loading, the 24 deg. contact-angle bearing gave longer life. For split-inner-ring bearings, optimal operating conditions were obtained with a 24 deg. contact angle and an inner-ring, land-guided cage, using outer-ring cooling in conjunction with low lubricant flow rates. Lower temperature and power losses were obtained with a single-outer-ring, land-guided cage for the 24 deg. contact-angle bearing having a relieved inner ring and partially relieved outer ring. Inner-ring temperatures were independent of lubrication mode and cage design. In comparison with measured values, reasonably good engineering correlation was obtained using the computer program SHABERTH for predicted bearing power loss and for inner- and outer-ring temperatures. The Parker formula for XCAV (used in SHABERTH, a measure of oil volume in the bearing cavity) may need to be refined to reflect bearing lubrication mode, cage design, and location of cage-controlling land.

  15. Small Horizontal Axis Wind Turbine under High Speed Operation: Study of Power Evaluation

    Science.gov (United States)

    Moh. M. Saad, Magedi; Mohd, Sofian Bin; Zulkafli, Mohd Fadhli Bin; Abdullah, Aslam Bin; Rahim, Mohammad Zulafif Bin; Subari, Zulkhairi Bin; Rosly, Nurhayati Binti

    2017-10-01

    Mechanical energy is produced through the rotation of wind turbine blades by air that convert the mechanical energy into electrical energy. Wind turbines are usually designed to be use for particular applications and design characteristics may vary depending on the area of use. The variety of applications is reflected on the size of turbines and their infrastructures, however, performance enhancement of wind turbine may start by analyzing the small horizontal axis wind turbine (SHAWT) under high wind speed operation. This paper analyzes the implementations of SHAWT turbines and investigates their performance in both simulation and real life. Depending on the real structure of the rotor geometry and aerodynamic test, the power performance of the SHAWT was simulated using ANSYS-FLUENT software at different wind speed up to 33.33 m/s (120km/h) in order to numerically investigate the actual turbine operation. Dynamic mesh and user define function (UDF) was used for revolving the rotor turbine via wind. Simulation results were further validated by experimental data and hence good matching was yielded. And for reducing the energy producing cost, car alternator was formed to be used as a small horizontal wind turbine. As a result, alternator-based turbine system was found to be a low-cost solution for exploitation of wind energy.

  16. Assessment of potential aerodynamic effects on personnel and equipment in proximity to high-speed train operations : safety of high-speed ground transportation systems

    Science.gov (United States)

    1999-12-01

    Amtrak is planning to provide high-speed passenger train service at speeds significantly higher than their current top speed of 125 mph, and with these higher speeds, there are concerns with safety from the aerodynamic effects created by a passing tr...

  17. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.

    2016-01-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...

  18. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.

    2016-01-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluat...... score, TS ≈ 0.37). The predicted high-speed streams show typical uncertainties in the arrival time of about 1 day and uncertainties in the speed of about 100 km/s. General advantages and disadvantages of the investigated solar wind models are diagnosed and outlined.......High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...

  19. Parallel point-multiplication architecture using combined group operations for high-speed cryptographic applications.

    Science.gov (United States)

    Hossain, Md Selim; Saeedi, Ehsan; Kong, Yinan

    2017-01-01

    In this paper, we propose a novel parallel architecture for fast hardware implementation of elliptic curve point multiplication (ECPM), which is the key operation of an elliptic curve cryptography processor. The point multiplication over binary fields is synthesized on both FPGA and ASIC technology by designing fast elliptic curve group operations in Jacobian projective coordinates. A novel combined point doubling and point addition (PDPA) architecture is proposed for group operations to achieve high speed and low hardware requirements for ECPM. It has been implemented over the binary field which is recommended by the National Institute of Standards and Technology (NIST). The proposed ECPM supports two Koblitz and random curves for the key sizes 233 and 163 bits. For group operations, a finite-field arithmetic operation, e.g. multiplication, is designed on a polynomial basis. The delay of a 233-bit point multiplication is only 3.05 and 3.56 μs, in a Xilinx Virtex-7 FPGA, for Koblitz and random curves, respectively, and 0.81 μs in an ASIC 65-nm technology, which are the fastest hardware implementation results reported in the literature to date. In addition, a 163-bit point multiplication is also implemented in FPGA and ASIC for fair comparison which takes around 0.33 and 0.46 μs, respectively. The area-time product of the proposed point multiplication is very low compared to similar designs. The performance ([Formula: see text]) and Area × Time × Energy (ATE) product of the proposed design are far better than the most significant studies found in the literature.

  20. Gain-scheduled Linear Quadratic Control of Wind Turbines Operating at High Wind Speed

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

    2007-01-01

    are then interpolated linearly to get a control law for the entire operating envelope. A nonlinear state estimator is designed as a combination of two unscented Kalman filters and a linear disturbance estimator. The gain-scheduling variable (wind speed) is then calculated from the output of these state estimators...

  1. IMPROVED METHOD OF DETERMINATION OF ECONOMIC EFFICIENCY OF CONSTRUCTION AND OPERATION OF HIGH SPEED MAINLINE IN UKRAINE

    Directory of Open Access Journals (Sweden)

    YU. S. Barash

    2014-01-01

    Full Text Available Purpose. To develop an advanced methodology and formulate the measures concerning the definition of economic efficiency of high-speed movement organization taking into account the operating experience of rapid transportations in Ukraine, travel time, number of stops on the route, schedule and the demand for these transportations. Methodology. The economic feasibility for appropriateness of high-speed movement organization in Ukraine is an investment project, which involves step-by-step money investment to the construction. To solve such problems one uses net present value, which UZ or newly created companies can get during the project realization and after its completion. Findings. On the basis of obtained studies one can state that the methodology of complex determination of construction efficiency and high-speed passenger trains operation taking into account the cost of infrastructure, rolling stock, impact of environmental factors, etc. was developed in the article. Originality. We propose a scientific approach to determine the economic efficiency of the construction and high-speed main lines operation. This approach, unlike the existing one, includes the improved principles of determining the passenger traffic, the cost of high-speed mainline construction, the number of rolling stock; optimizes income and expenditure calculations in the context of competitive advantages and impact of the external factors on the company. For the first time it was taken into account the transit flow of passengers departing from CIS countries to the vacation in the Crimea, the Carpathians, Odessa and Lviv regions. The account of these factors increases the feasibility of administrative decisions concerning ensuring the efficiency of high-speed traffic functioning. Practical value. The proposed methodology and the research results allowed determining the construction reasonability of high-speed mainline for the passenger trains with a speed at least250 km/h in

  2. Cutting efficiency of diamond burs operated with electric high-speed dental handpiece on zirconia.

    Science.gov (United States)

    Nakamura, Keisuke; Katsuda, Yusuke; Ankyu, Shuhei; Harada, Akio; Tenkumo, Taichi; Kanno, Taro; Niwano, Yoshimi; Egusa, Hiroshi; Milleding, Percy; Örtengren, Ulf

    2015-08-28

    Zirconia-based dental restorations are becoming used more commonly. However, limited attention has been given to the difficulties experienced, concerning cutting, in removing the restorations when needed. The aim of the present study was to compare the cutting efficiency of diamond burs, operated using an electric high-speed dental handpiece, on zirconia (Zir) with those on lithium disilicate glass-ceramic (LD) and leucite glass-ceramic (L). In addition, evaluation of the cutting efficiency of diamond burs on Zir of different thicknesses was performed. Specimens of Zir were prepared with thicknesses of 0.5, 1.0, 2.0, and 4.0 mm, and specimens of LD and L were prepared with a thickness of 1.0 mm. Cutting tests were performed using diamond burs with super coarse (SC) and coarse (C) grains. The handpiece was operated at 150,000 rpm with a cutting force of 0.9 N. The results demonstrated that cutting of Zir took about 1.5- and 7-fold longer than cutting of LD and L, respectively. The SC grains showed significantly higher cutting efficiency on Zir than the C grains. However, when the thickness of Zir increased, the cutting depth was significantly decreased. As it is suggested that cutting of zirconia is time consuming, this should be taken into consideration in advance when working with zirconia restorations. © 2015 Eur J Oral Sci.

  3. Progress Towards High-Speed Operation of the Magnetorotational Instability Experiment and Diagnostic Development

    Science.gov (United States)

    Gilson, E. P.; Caspary, K.; Choi, D.; Ebrahimi, F.; Goodman, J.; Ji, H.; Lysandrou, M.; Sloboda, P.; Tabbutt, M.

    2017-10-01

    Estimates and simulations both suggest that the Princeton MRI experiment must operate with inner cylinder rotation rates > 1,500 rpm, corresponding to magnetic Reynolds numbers Rm > 3 , in order for the flow to be unstable to the MRI. Results will be presented demonstrating progress towards high-speed operation while avoiding adverse effects from large dynamic pressure and heat. Recent studies show that conductive end caps increase the magnitude of the saturated MRI signal, enabling easier detection. However, motor control feedback and pneumatically-driven brakes must be used to maintain control when forces arise from the interaction between induced currents in the rotating end caps and the 3,000 G applied magnetic field. The use of Hall probes and strain gauges to measure the azimuthal magnetic field and the torque at the inner cylinder will be discussed. Results from the Spectral Finite Element and Navier Stokes code have been used to better understand the expected shape of the MRI threshold curve with conducting end caps, the nature of the forces on the end caps, and to predict the magnetic fields and torques at the inner cylinder that result from the onset of the MRI.

  4. High speed data converters

    CERN Document Server

    Ali, Ahmed MA

    2016-01-01

    This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.

  5. Series operation of power MOSFETs for high-speed, high-voltage switching applications

    Science.gov (United States)

    Baker, R. J.; Johnson, B. P.

    1993-06-01

    Series operation of power metal-oxide semiconductor field-effect transistors (MOSFETs) to increase their effective hold off voltage is described. The design procedure presented is a modification of a recently reported [Baker and Johnson, Rev. Sci. Instrum. 63, 5799 (1992)] method. Comments are made on implementing MOSFET stacks in various types of instrumentation.

  6. Novel HDD-type SNDM ferroelectric data storage system aimed at high-speed data transfer with single probe operation.

    Science.gov (United States)

    Hiranaga, Yoshiomi; Uda, Tomoya; Kurihashi, Yuichi; Tanaka, Kenkou; Cho, Yasuo

    2007-12-01

    In this study, several read/write tests were conducted using a novel ferroelectric data storage test system equipped with a spindle motor, targeted at high-speed data transfer using a single probe head. A periodically inverted signal can be read out correctly with a bit rate of 100 kbps using this test system, and 10 Mbps data transfer is also possible during writing operations. The effect of a dc-offset voltage applied to the writing waveform with high-speed probe scanning is discussed. In addition, a novel noncontact probe height control technique was adopted to solve the problem of tip abrasion.

  7. Robustness of Multiple High Speed TCP CUBIC Connections Under Severe Operating Conditions

    DEFF Research Database (Denmark)

    Pilimon, Artur; Ruepp, Sarah Renée; Berger, Michael Stübert

    2015-01-01

    on and supported by packet-level simulations. The results show that the aggressive nature of CUBIC’s nonlinear congestion window control principle causes a degradation of the time-average throughput at the moderate level of random packet loss even under increasing Round-Trip-Time of the flow. However......We study the adaptation capabilities and robustness of the high-speed TCP CUBIC algorithm. For this purpose we consider a network environment with variable and high random packet loss and a large Bandwidth-Delay product, shared by multiple heterogeneous TCP connections. The analysis is based...

  8. Assessment of Gearbox Operational Loads and Reliability under High Mean Wind Speeds

    DEFF Research Database (Denmark)

    Dabrowski, Dariusz; Natarajan, Anand

    2015-01-01

    This paper investigates the dynamic loads occurring in the drivetrain of wind turbines with a focus on offshore applications. Herein a model of the gearbox of the 5 MW wind turbine is presented. The model is developed in a multi-body framework using commercial software MSC ADAMS. Validation...... of the model was based on the experimental data provided by NREL for 750 kW prototype gearbox. Failures of gearboxes caused by high dynamic loads have a significant influence on the cost of operation of wind farms. For these reasons in the study, the probability of failure of the gearbox working in an offshore...... operating gust, normal turbulence model and extreme turbulence model. In the paper, loads in the planetary gear are quantified as well as the torsional moments in the main shaft. On the basis of simulation results the annual probability of failure of the gearbox in a wind turbine with soft storm controller...

  9. Theoretical Study of Operational Limits of High-Speed Quantum Dot Lasers

    Science.gov (United States)

    2012-09-09

    strained -layer InGaAs quantum - well improvement of an InAs quantum dot AlGaAs –GaAs– InGaAs –InAs... AlGaAs –GaAs– InGaAs heterostructure diode laser operation Appl. Phys. Lett. 80 1126–8 [20] Walter G, Chung T and Holonyak N 2002 Coupled-stripe quantum - well ...8] Tokranov V, Yakimov M, van Eisden J and Oktyabrsky S 2006 Tunnel quantum well -on-dots InGaAs –InAs high-gain medium for laser diodes Proc.

  10. Modern Trends Used In Operating Systems For High Speed Computing Applications

    OpenAIRE

    Qurat-ul-Ain Malik; M. Aqeel Iqbal; Nauman Khan,; Hamza Khan; Haider Ali

    2010-01-01

    Operating system researches traditionally consist of adding new functions to the operating system in other words inventing and evaluating new methods for performing functions. Operating systems are the single most complex piece of software in a computer system, which contains hundreds of thousands, if not millions, of lines of code. Today’s operating system research is directed at finding new ways to structure the operating system in order to increase its flexibility, allowing it to adapt to ...

  11. High speed heterostructure devices

    CERN Document Server

    Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard

    1994-01-01

    Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

  12. DEVELOPMENT OF NEUROMORPHIC SIFT OPERATOR WITH APPLICATION TO HIGH SPEED IMAGE MATCHING

    Directory of Open Access Journals (Sweden)

    M. Shankayi

    2015-12-01

    Full Text Available There was always a speed/accuracy challenge in photogrammetric mapping process, including feature detection and matching. Most of the researches have improved algorithm's speed with simplifications or software modifications which increase the accuracy of the image matching process. This research tries to improve speed without enhancing the accuracy of the same algorithm using Neuromorphic techniques. In this research we have developed a general design of a Neuromorphic ASIC to handle algorithms such as SIFT. We also have investigated neural assignment in each step of the SIFT algorithm. With a rough estimation based on delay of the used elements including MAC and comparator, we have estimated the resulting chip's performance for 3 scenarios, Full HD movie (Videogrammetry, 24 MP (UAV photogrammetry, and 88 MP image sequence. Our estimations led to approximate 3000 fps for Full HD movie, 250 fps for 24 MP image sequence and 68 fps for 88MP Ultracam image sequence which can be a huge improvement for current photogrammetric processing systems. We also estimated the power consumption of less than10 watts which is not comparable to current workflows.

  13. Development of Neuromorphic Sift Operator with Application to High Speed Image Matching

    Science.gov (United States)

    Shankayi, M.; Saadatseresht, M.; Bitetto, M. A. V.

    2015-12-01

    There was always a speed/accuracy challenge in photogrammetric mapping process, including feature detection and matching. Most of the researches have improved algorithm's speed with simplifications or software modifications which increase the accuracy of the image matching process. This research tries to improve speed without enhancing the accuracy of the same algorithm using Neuromorphic techniques. In this research we have developed a general design of a Neuromorphic ASIC to handle algorithms such as SIFT. We also have investigated neural assignment in each step of the SIFT algorithm. With a rough estimation based on delay of the used elements including MAC and comparator, we have estimated the resulting chip's performance for 3 scenarios, Full HD movie (Videogrammetry), 24 MP (UAV photogrammetry), and 88 MP image sequence. Our estimations led to approximate 3000 fps for Full HD movie, 250 fps for 24 MP image sequence and 68 fps for 88MP Ultracam image sequence which can be a huge improvement for current photogrammetric processing systems. We also estimated the power consumption of less than10 watts which is not comparable to current workflows.

  14. Analysis of foil bearings for high speed operation in cryogenic applications

    Science.gov (United States)

    Carpino, Marc

    1991-01-01

    The general objective of this project is to develop analysis tools which are required for the design of foil bearings to be used in cryogenic applications. During the second year of this project, a general analysis approach and code for journal bearings operating under steady state conditions will be completed. This will be followed by the initiation of an investigation into transient behavior of foil bearings to determine their performance in rotor systems. Foil bearings have been proposed as an alternative to rolling element bearings for use in cryogenic turbopumps in liquid propellant rocket engines. This type of bearing offers several advantages over rolling element bearings since they would use the cryogenic pump fluid for a lubricant and have structural flexibility. These bearings have the potential of high reliability and long life. The bearing surface is constructed of a 'foil' which resists deflection by a combination of bending, membrane, and elastic foundation effects. The relative motion between the rotating shaft and the foil causes pressure in the fluid film to develop. This pressure deflects the the foil surface away from the shaft. Once a full fluid film is established between the foil and the rotor shaft, contact no longer takes place and there is no subsequent wear of the surfaces. The flexible foil structure of the bearing allows it to compensate for minor tolerance and manufacturing defects. This same flexibility also has a significant effect on the dynamic performance of the rotor-bearing system.

  15. High Speed Ice Friction

    Science.gov (United States)

    Seymour-Pierce, Alexandra; Sammonds, Peter; Lishman, Ben

    2014-05-01

    Many different tribological experiments have been run to determine the frictional behaviour of ice at high speeds, ostensibly with the intention of applying results to everyday fields such as winter tyres and sports. However, experiments have only been conducted up to linear speeds of several metres a second, with few additional subject specific studies reaching speeds comparable to these applications. Experiments were conducted in the cold rooms of the Rock and Ice Physics Laboratory, UCL, on a custom built rotational tribometer based on previous literature designs. Preliminary results from experiments run at 2m/s for ice temperatures of 271 and 263K indicate that colder ice has a higher coefficient of friction, in accordance with the literature. These results will be presented, along with data from further experiments conducted at temperatures between 259-273K (in order to cover a wide range of the temperature dependent behaviour of ice) and speeds of 2-15m/s to produce a temperature-velocity-friction map for ice. The effect of temperature, speed and slider geometry on the deformation of ice will also be investigated. These speeds are approaching those exhibited by sports such as the luge (where athletes slide downhill on an icy track), placing the tribological work in context.

  16. A Soft Rough-Fuzzy Preference Set-Based Evaluation Method for High-Speed Train Operation Diagrams

    Directory of Open Access Journals (Sweden)

    Dingjun Chen

    2016-01-01

    Full Text Available This paper proposes a method of high-speed railway train operation diagram evaluation based on preferences of locomotive operation, track maintenance, S & C, vehicles and other railway departments, and customer preferences. The application of rough set-based attribute reduction obtains the important relative indicators by eliminating excessive and redundant evaluation indicators. Soft fuzzy set theory is introduced for the overall evaluation of train operation diagrams. Each expert utilizes a set of indicators during evaluation based on personal preference. In addition, soft fuzzy set theory is applied to integrate the information obtained via expert evaluation in order to obtain an overall evaluation. The proposed method was validated by a case study. Results demonstrate that the proposed method flexibly expresses the subjective judgments of experts while effectively and reasonably handling the uncertainty of information, which is consistent with the judgment process of humans. The proposed method is also applicable to the evaluation of train operation schemes which consist of multiple diagrams.

  17. High Speed On-Wafer Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  18. Conceptual design and kinematic analysis of a novel parallel robot for high-speed pick-and-place operations

    Science.gov (United States)

    Meng, Qizhi; Xie, Fugui; Liu, Xin-Jun

    2017-11-01

    This paper deals with the conceptual design, kinematic analysis and workspace identification of a novel four degrees-of-freedom (DOFs) high-speed spatial parallel robot for pick-and-place operations. The proposed spatial parallel robot consists of a base, four arms and a 1½ mobile platform. The mobile platform is a major innovation that avoids output singularity and offers the advantages of both single and double platforms. To investigate the characteristics of the robot's DOFs, a line graph method based on Grassmann line geometry is adopted in mobility analysis. In addition, the inverse kinematics is derived, and the constraint conditions to identify the correct solution are also provided. On the basis of the proposed concept, the workspace of the robot is identified using a set of presupposed parameters by taking input and output transmission index as the performance evaluation criteria.

  19. High-speed pulse techniques

    CERN Document Server

    Coekin, J A

    1975-01-01

    High-Speed Pulse Techniques covers the many aspects of technique in digital electronics and encompass some of the more fundamental factors that apply to all digital systems. The book describes the nature of pulse signals and their deliberate or inadvertent processing in networks, transmission lines and transformers, and then examines the characteristics and transient performance of semiconductor devices and integrated circuits. Some of the problems associated with the assembly of these into viable systems operating at ultra high speed are also looked at. The book examines the transients and w

  20. BRAKING OF HIGH-SPEED PASSENGER TRAINS WITH REGARD TO THE OPERATION OF AN ELECTROMAGNETIC RAIL BRAKE

    Directory of Open Access Journals (Sweden)

    N. Je. Naumenko

    2009-03-01

    Full Text Available The research of the braking process of high-speed passenger train with the use of compressed-air, electropneumatic and electromagnetic track brakes is carried out. The dependences of braking distance on motion speed for vehicles equipped by block or disk brakes as well as for a case of electromagnetic track brakes used in addition to existing braking means.

  1. 75 FR 25927 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

    Science.gov (United States)

    2010-05-10

    ... plane of the rails. For every curve, there is a balance speed at which the cant deficiency is zero based... includes a proposal that vehicles with minor variations in their physical properties (such as suspension... represented to FRA to have truck and suspension components nearly identical to the Comet IV car already in...

  2. 78 FR 16051 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

    Science.gov (United States)

    2013-03-13

    ... plane of the rails. For every curve, there is a balance speed at which the cant deficiency is zero based... suspension, mass, interior arrangements, or dimensions) that do not result in significant changes to their.... The Comet V car was represented to FRA to have truck and suspension components nearly identical to the...

  3. HIGH SPEED CAMERA

    Science.gov (United States)

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  4. High speed curving performance of rail vehicles

    Science.gov (United States)

    2015-03-23

    On March 13, 2013, the Federal Railroad Administration (FRA) published a final rule titled Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations which amended the Track Safety Standards (49 CFR Part213) and ...

  5. High Speed Viterbi Decoder Architecture

    DEFF Research Database (Denmark)

    Paaske, Erik; Andersen, Jakob Dahl

    1998-01-01

    The fastest commercially available Viterbi decoders for the (171,133) standard rate 1/2 code operate with a decoding speed of 40-50 Mbit/s (net data rate). In this paper we present a suitable architecture for decoders operating with decoding speeds of 150-300 Mbit/s....

  6. Remote operation over low speed, high latency links; Operacao remota confiavel usando circuitos de baixa velocidade e alta latencia

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Marcelo D.; Nunes, Ildemar P. [Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    Remote Control and monitoring of a compressor station with more than 3000 tags can be a hard task to accomplish over a low speed satellite link. This paper presents Datasync, an application specially developed to provide acceptable performance levels over a VSAT link. One of its main features is to enable the establishment of communication dead bands. The dead bands can be altered while the application is running (no restart is needed), so that the operator is able to increase a specific tag's dead band immediately after detecting that it is reporting too many exceptions, which would cause an increase on the traffic and response times. (author)

  7. Jane's high-speed marine transportation

    National Research Council Canada - National Science Library

    Phillips, S.J

    1998-01-01

    The purpose of this book is to provide a comprehensive reference yearbook covering the design, build and operation of high-speed marine transportation, worldwide, an annually updated reference book...

  8. High-Speed and Low-Energy Flip-Flop Operation of Asymmetric Active-Multimode Interferometer Bi-Stable Laser Diodes

    DEFF Research Database (Denmark)

    Jiang, Haisong; Chaen, Yutaka; Hagio, Takuma

    2011-01-01

    High-speed (121/25 ps rise/fall time) and low-switching energy (7.1 and 3.4 fJ) alloptical flip-flop operation of single-wavelength high-mesa asymmetric active-MMI bi-stable laser diodes is demonstrated for the first time using 25 ps long switching pulses.......High-speed (121/25 ps rise/fall time) and low-switching energy (7.1 and 3.4 fJ) alloptical flip-flop operation of single-wavelength high-mesa asymmetric active-MMI bi-stable laser diodes is demonstrated for the first time using 25 ps long switching pulses....

  9. High speed preprocessing system

    Indian Academy of Sciences (India)

    (a) Digitizing and writing the video data in the memory at HR rate, and (b) once the data are ready in the memory, reading the data and generating the LR image. Thus the execution time mainly depends on (i) processor speed, and (ii) the time taken for fetching video information/data. Figure 1. Hardware block diagram. 514.

  10. 14 CFR 23.253 - High speed characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High speed characteristics. 23.253 Section... Requirements § 23.253 High speed characteristics. If a maximum operating speed VMO/MMO is established under § 23.1505(c), the following speed increase and recovery characteristics must be met: (a) Operating...

  11. High-speed highly temperature stable 980 nm VCSELs operating at 25 Gb/s at up to 85 °C for short reach optical interconnects

    Science.gov (United States)

    Mutig, Alex; Lott, James A.; Blokhin, Sergey A.; Moser, Philip; Wolf, Philip; Hofmann, Werner; Nadtochiy, Alexey M.; Bimberg, Dieter

    2011-03-01

    The progressive penetration of optical communication links into traditional copper interconnect markets greatly expands the applications of vertical cavity surface emitting lasers (VCSELs) for the next-generation of board-to-board, moduleto- module, chip-to-chip, and on-chip optical interconnects. Stability of the VCSEL parameters at high temperatures is indispensable for such applications, since these lasers typically reside directly on or near integrated circuit chips. Here we present 980 nm oxide-confined VCSELs operating error-free at bit rates up to 25 Gbit/s at temperatures as high as 85 °C without adjustment of the drive current and peak-to-peak modulation voltage. The driver design is therefore simplified and the power consumption of the driver electronics is lowered, reducing the production and operational costs. Small and large signal modulation experiments at various temperatures from 20 up to 85 °C for lasers with different oxide aperture diameters are presented in order to analyze the physical processes controlling the performance of the VCSELs. Temperature insensitive maximum -3 dB bandwidths of around 13-15 GHz for VCSELs with aperture diameters of 10 μm and corresponding parasitic cut-off frequencies exceeding 22 GHz are observed. Presented results demonstrate the suitability of our VCSELs for practical high speed and high temperature stable short-reach optical links.

  12. Ultra high-speed sorting.

    Science.gov (United States)

    Leary, James F

    2005-10-01

    Cell sorting has a history dating back approximately 40 years. The main limitation has been that, although flow cytometry is a science, cell sorting has been an art during most of this time. Recent advances in assisting technologies have helped to decrease the amount of expertise necessary to perform sorting. Droplet-based sorting is based on a controlled disturbance of a jet stream dependent on surface tension. Sorting yield and purity are highly dependent on stable jet break-off position. System pressures and orifice diameters dictate the number of droplets per second, which is the sort rate limiting step because modern electronics can more than handle the higher cell signal processing rates. Cell sorting still requires considerable expertise. Complex multicolor sorting also requires new and more sophisticated sort decisions, especially when cell subpopulations are rare and need to be extracted from background. High-speed sorting continues to pose major problems in terms of biosafety due to the aerosols generated. Cell sorting has become more stable and predictable and requires less expertise to operate. However, the problems of aerosol containment continue to make droplet-based cell sorting problematical. Fluid physics and cell viability restraints pose practical limits for high-speed sorting that have almost been reached. Over the next 5 years there may be advances in fluidic switching sorting in lab-on-a-chip microfluidic systems that could not only solve the aerosol and viability problems but also make ultra high-speed sorting possible and practical through massively parallel and exponential staging microfluidic architectures.

  13. High-speed AC motors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. High-Speed Rail & Air Transport Competition

    NARCIS (Netherlands)

    Adler, Nicole; Nash, Chris; Pels, Eric

    2008-01-01

    This paper develops a methodology to assess transport infrastructure investments and their effects on a Nash equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub and spoke legacy airlines and low cost carriers,

  15. High-speed Rail & air transport competition

    NARCIS (Netherlands)

    Adler, N; Nash, C.; Pels, E.

    2010-01-01

    This research develops a methodology to assess infrastructure investments and their effects on transport equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub-and-spoke legacy airlines and regional low-cost

  16. High speed rail distribution study.

    Science.gov (United States)

    2016-08-01

    The Texas Central Partners are in the process of developing a high speed rail line connecting : Houston and Dallas, Texas. Ultimately, plans are for 8 car trains that accommodate 200 people per : vehicle scheduled every 30 minutes. In addition, Texas...

  17. High-Speed Electrochemical Imaging.

    Science.gov (United States)

    Momotenko, Dmitry; Byers, Joshua C; McKelvey, Kim; Kang, Minkyung; Unwin, Patrick R

    2015-09-22

    The design, development, and application of high-speed scanning electrochemical probe microscopy is reported. The approach allows the acquisition of a series of high-resolution images (typically 1000 pixels μm(-2)) at rates approaching 4 seconds per frame, while collecting up to 8000 image pixels per second, about 1000 times faster than typical imaging speeds used up to now. The focus is on scanning electrochemical cell microscopy (SECCM), but the principles and practicalities are applicable to many electrochemical imaging methods. The versatility of the high-speed scan concept is demonstrated at a variety of substrates, including imaging the electroactivity of a patterned self-assembled monolayer on gold, visualization of chemical reactions occurring at single wall carbon nanotubes, and probing nanoscale electrocatalysts for water splitting. These studies provide movies of spatial variations of electrochemical fluxes as a function of potential and a platform for the further development of high speed scanning with other electrochemical imaging techniques.

  18. EAM-based high-speed 100-km OFDM transmission featuring tolerant modulator operation enabled using SSII cancellation.

    Science.gov (United States)

    Chen, Hsing-Yu; Wei, Chia-Chien; Lu, I-Cheng; Chen, Yu-Chao; Chu, Hsuan-Hao; Chen, Jyehong

    2014-06-16

    In this study, a technique was developed to compensate for nonlinear distortion through cancelling subcarrier-to-subcarrier intermixing interference (SSII) in an electroabsorption modulator (EAM)-based orthogonal frequency-division multiplexing (OFDM) transmission system. The nonlinear distortion to be compensated for is induced by both EAM nonlinearity and fiber dispersion. Because an OFDM signal features an inherently high peak-to-average power ratio, a trade-off exists between the optical modulation index (OMI) and modulator nonlinearity. Therefore, the nonlinear distortion limits the operational tolerance of the bias voltage and the driving power to a small region. After applying the proposed SSII cancellation, the OMI of an OFDM signal was increased yielding only a small increment of nonlinear distortion, and the tolerance region of the operational conditions was also increased. By employing the proposed scheme, this study successfully demonstrates 50-Gbps OFDM transmission over 100-km dispersion-uncompensated single-mode fiber based on a single 10-GHz EAM.

  19. High Speed Compressor Study

    Science.gov (United States)

    2011-12-21

    Davey G. The Design and Testing of a Stirling Cycle Domestic Freezer. Proc. of Conference on Applications for Natural Refrigerants , held in Aarhus...carried out on a relatively old design of compressor, initially developed for use with a Stirling cycle domestic freezer12, and subsequently used in a...limit’, and is suitable for high cycle fatigue. Beryllium copper has been largely superseded by stainless steel, which is more readily available

  20. High-speed photonics interconnects

    CERN Document Server

    Chrostowski, Lukas

    2013-01-01

    Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed

  1. 14 CFR 25.253 - High-speed characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High-speed characteristics. 25.253 Section...-speed characteristics. (a) Speed increase and recovery characteristics. The following speed increase and recovery characteristics must be met: (1) Operating conditions and characteristics likely to cause...

  2. Spray-irrigation system attached to high-speed drills for simultaneous prevention of local heating and preservation of a clear operative field in spinal surgery.

    Science.gov (United States)

    Sasaki, Manabu; Morris, Shayne; Goto, Tetsu; Iwatsuki, Koichi; Yoshimine, Toshiki

    2010-01-01

    Heat generation due to drilling during spinal surgery is potentially hazardous to nerves. Saline irrigation is often performed to prevent such local heating, but sometimes floods and obscures the operative field. We have developed a spray-irrigation system for attachment to high-speed drills, which sprays saline solution with an air-jet in the direction of the surface cut by the drill. We anticipated that this air jet would create a clearer operative view by displacing excess fluid, and would also provide an added cooling effect greater than that of irrigation with saline. This study was designed to evaluate these predicted effects of the spray-irrigation system compared to conventional irrigation. A thermography study was performed to confirm the cooling effect of the spray-irrigation system. A plaster board coated with adhesives was drilled at 100,000 rpm along a 10-cm line for a duration of 20 seconds. Thermograms were recorded every minute, without cooling, with irrigation, and with the spray-irrigation system. To examine the operative views, continuous drilling for a period of seconds was performed with conventional irrigation and with the spray-irrigation system. Local heating was inhibited by the spray-irrigation system to 14-30% of that with irrigation. A clear operative field was maintained during continuous drilling using the spray-irrigation system through the air-jet action of the system. The spray-irrigation system can simultaneously provide effective cooling and a clear operative field during surgical manipulations with high-speed drills.

  3. High-speed OTDM switching

    DEFF Research Database (Denmark)

    Jepsen, Kim Stokholm; Mikkelsen, Benny; Clausen, Anders

    1998-01-01

    Optical TDM (OTDM) continues to be of interest both for point-point transmission and as a networking technology for both LANs and long-distance fibre transmission. Recent research has demonstrated enabling techniques for OTDM networks at high speeds. In conclusion, OTDM is emerging as an attracti...

  4. Resonance control of a silicon micro-ring resonator modulator under high-speed operation using the intrinsic defect-mediated photocurrent.

    Science.gov (United States)

    Wang, Zhao; Paez, Dixon; El-Rahman, Ahmed I Abd; Wang, Peng; Dow, Liam; Cartledge, John C; Knights, Andrew P

    2017-10-02

    A method to stabilize the resonance wavelength of a depletion-type silicon micro-ring resonator modulator during high-speed operation is described. The method utilizes the intrinsic defect-mediated photo-absorption of a silicon waveguide and results in a modulator chip fabrication process that is free of heterogeneous integration (for example using germanium), thus significantly reducing the complexity and cost of manufacture. Residual defects, present after p-n junction formation, are found to produce an adequate photocurrent for use as a feedback signal, while an integrated heater is used to compensate for thermal drift via closed-loop control. The photocurrent is measured by a source-meter, which simultaneously provides a DC bias to the integrated heater during high-speed operation. A drop-port or an integrated extrinsic detector is not needed. This feedback control method is experimentally demonstrated via a computer-aided proportional-integral-differential loop. The resonance locking is validated for 12.5 Gb/s intensity modulation in a back-to-back bit-error-rate measurement. The stabilization method described is not limited to a specific modulator design and is compatible with speeds greatly in excess of 12.5 Gb/s, in contrast to the bandwidth limitation of other stabilization methods that rely on intrinsic photo-carrier generation through non-linear processes such as two-photon-absorption. Further, the use of intrinsic defects present after standard fabrication insures that no excess loss is associated with this stabilization method.

  5. High-Speed Rail & Air Transport Competition

    OpenAIRE

    Nicole Adler; Chris Nash; Eric Pels

    2008-01-01

    This paper develops a methodology to assess transport infrastructure investments and their effects on a Nash equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub and spoke legacy airlines and low cost carriers, maximize profit functions via prices, frequency and train/plane sizes, given infrastructure provision and costs and environmental charges. The methodology is subsequently applied to all 27 Europea...

  6. Study and implementation high speed operating of induced magnetization machines; Etude et mise en oeuvre de machines a aimantation induite fonctionnant a haute vitesse

    Energy Technology Data Exchange (ETDEWEB)

    Alhassoun, Y.

    2005-05-15

    Actually, electromechanical machines are characterized by their low cost and reduced maintenance. Therefore, new types of magnetic materials such as soft magnetic composites (SMC), have to be considered not only for multiple applications (small motors for automotive) for cost reduction, but also when considering other special requirements such as high speed drive (aircraft and space applications). Our report of thesis is articulated around four chapters: The first chapter show the various types of magnetic interactions used in the electromagnetic actuators. The second chapter is devoted to the modelling of the induced magnetic machines by analytical resolution of equations of the field in two dimensions. The third chapter presents the four configurations prototypes of switched reluctance machine which mix the exploitation of laminated materials and the soft magnetic powders. The fourth chapter discusses the critical conditions of this machines operating at high speed. We conclude, insisting on the efforts carried out in term of analytical modelling of the induced magnetization machines for their dimensions and exploited in this same structure, the soft magnetic composite materials. The results show the potential of soft magnetic powders when considering in particular the high frequency losses and their ability to favour the heat dissipation in this structure. (author)

  7. High speed cryogenic monodisperse targets

    Science.gov (United States)

    Boukharov, A.; Vishnevkii, E.

    2017-11-01

    The basic possibility of creation of high speed cryogenic monodisperse targets is shown. According to calculations at input of thin liquid cryogenic jets with a velocity of bigger 100 m/s in vacuum the jets don’t manage to freeze at distance to 1 mm and can be broken into monodisperse drops. Drops due to evaporation are cooled and become granules. High speed cryogenic monodisperse targets have the following advantages: direct input in vacuum (there is no need for a chamber of a triple point chamber and sluices), it is possible to use the equipment of a cluster target, it is possible to receive targets with a diameter of D 100m/s), exact synchronization of the target hitting moment in a beam with the moment of sensors turning on.

  8. High Speed SPM of Functional Materials

    Energy Technology Data Exchange (ETDEWEB)

    Huey, Bryan D. [Univ. of Connecticut, Storrs, CT (United States)

    2015-08-14

    The development and optimization of applications comprising functional materials necessitates a thorough understanding of their static and dynamic properties and performance at the nanoscale. Leveraging High Speed SPM and concepts enabled by it, efficient measurements and maps with nanoscale and nanosecond temporal resolution are uniquely feasible. This includes recent enhancements for topographic, conductivity, ferroelectric, and piezoelectric properties as originally proposed, as well as newly developed methods or improvements to AFM-based mechanical, friction, thermal, and photoconductivity measurements. The results of this work reveal fundamental mechanisms of operation, and suggest new approaches for improving the ultimate speed and/or efficiency, of data storage systems, magnetic-electric sensors, and solar cells.

  9. Aerodynamic design on high-speed trains

    Science.gov (United States)

    Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li

    2016-04-01

    Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

  10. CONSIDERATION OF AERODYNAMIC IMPACT IN SETTING THE MAXIMUM PERMISSIBLE SPEEDS OF HIGH-SPEED TRAIN

    Directory of Open Access Journals (Sweden)

    S. T. Djabbarov

    2017-10-01

    Full Text Available Purpose. Studies of the effect of aerodynamic pressure on the maximum permissible speeds of a high-speed train on the existing railway infrastructure. Methodology. The study of the magnitude and direction of the aerodynamic pressure, its effect on the maximum speeds of a high-speed train was carried out on a train model composed of axisymmetric bodies with conical forms of head and tail parts. Findings. Determined the values of the aerodynamic pressure at different distances from the train are, when the high-speed train moves at a speed of 200 km/h or more. The maximum speeds of a high-speed train are determined taking into account the state of the infrastructure of the existing railway, ensuring the safe operation of a high-speed railway. Originality. Theoretical studies of aerodynamic pressure from secondary air currents formed during the movement of high-speed trains are performed on a model of a train composed of identical axisymmetric bodies with conical forms of head and tail moving in a compressible medium. The results of the research allow the regularity of the change in aerodynamic pressure during the movement of a high-speed train. Practical value. The obtained results allow to establish: 1 the maximum permissible speeds of a high-speed train taking into account the technical condition of permanent devices and structures of the existing railway infrastructure; 2 technical parameters of individual objects and structural elements of the infrastructure of high-speed iron subjected to the effect of aerodynamic pressure for a given maximum speed of high-speed trains.

  11. Belt conveyor dynamics in transient operation for speed control

    NARCIS (Netherlands)

    He, D.; Pang, Y.; Lodewijks, G.

    2016-01-01

    Belt conveyors play an important role in continuous dry bulk material transport, especially at the mining industry. Speed control is expected to reduce the energy consumption of belt conveyors. Transient operation is the operation of increasing or decreasing conveyor speed for speed control.

  12. Towards high-speed scanning tunneling microscopy

    NARCIS (Netherlands)

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  13. High speed nanofluidic protein accumulator.

    Science.gov (United States)

    Wu, Dapeng; Steckl, Andrew J

    2009-07-07

    Highly efficient preconcentration is a crucial prerequisite to the identification of important protein biomarkers with extremely low abundance in target biofluids. In this work, poly(dimethylsiloxane) microchips integrated with 10 nm polycarbonate nanopore membranes were utilized as high-speed protein accumulators. Double-sided injection control of electrokinetic fluid flow in the sample channel resulted in highly localized protein accumulation at a very sharp point in the channel cross point. This greatly enhanced the ability to detect very low levels of initial protein concentration. Fluorescein labeled human serum albumin solutions of 30 and 300 pM accumulated to 3 and 30 microM in only 100 s. Initial solutions as low as 0.3 and 3 pM could be concentrated within 200 s to 0.3 and 3 microM, respectively. This demonstrates a approximately 10(5)-10(6) accumulation factor, and an accumulation rate as high as 5000/sec, yielding a >10x improvement over most results reported to date.

  14. Next Generation Modeling Technology for High Speed Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a new generation of high speed rotorcraft has been hampered by both an absence of strong predictive methods for rotors operating at very high advance...

  15. Robust Diagnosis Method Based on Parameter Estimation for an Interturn Short-Circuit Fault in Multipole PMSM under High-Speed Operation

    Directory of Open Access Journals (Sweden)

    Jewon Lee

    2015-11-01

    Full Text Available This paper proposes a diagnosis method for a multipole permanent magnet synchronous motor (PMSM under an interturn short circuit fault. Previous works in this area have suffered from the uncertainties of the PMSM parameters, which can lead to misdiagnosis. The proposed method estimates the q-axis inductance (Lq of the faulty PMSM to solve this problem. The proposed method also estimates the faulty phase and the value of G, which serves as an index of the severity of the fault. The q-axis current is used to estimate the faulty phase, the values of G and Lq. For this reason, two open-loop observers and an optimization method based on a particle-swarm are implemented. The q-axis current of a healthy PMSM is estimated by the open-loop observer with the parameters of a healthy PMSM. The Lq estimation significantly compensates for the estimation errors in high-speed operation. The experimental results demonstrate that the proposed method can estimate the faulty phase, G, and Lq besides exhibiting robustness against parameter uncertainties.

  16. Robust Diagnosis Method Based on Parameter Estimation for an Interturn Short-Circuit Fault in Multipole PMSM under High-Speed Operation.

    Science.gov (United States)

    Lee, Jewon; Moon, Seokbae; Jeong, Hyeyun; Kim, Sang Woo

    2015-11-20

    This paper proposes a diagnosis method for a multipole permanent magnet synchronous motor (PMSM) under an interturn short circuit fault. Previous works in this area have suffered from the uncertainties of the PMSM parameters, which can lead to misdiagnosis. The proposed method estimates the q-axis inductance (Lq) of the faulty PMSM to solve this problem. The proposed method also estimates the faulty phase and the value of G, which serves as an index of the severity of the fault. The q-axis current is used to estimate the faulty phase, the values of G and Lq. For this reason, two open-loop observers and an optimization method based on a particle-swarm are implemented. The q-axis current of a healthy PMSM is estimated by the open-loop observer with the parameters of a healthy PMSM. The Lq estimation significantly compensates for the estimation errors in high-speed operation. The experimental results demonstrate that the proposed method can estimate the faulty phase, G, and Lq besides exhibiting robustness against parameter uncertainties.

  17. High-tech maintenance for high-speed trains

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Javier Rutz [Nertus Mantenimiento Ferroviario, S.A., Madrid (Spain); Hofmann, Manfred [Siemens AG, Erlangen (Germany). Mobility Div., Integrated Services

    2011-03-15

    Reliable, punctual trains cannot do without professional maintenance. Nertus S.A., a joint subsidiary of Siemens and Renfe, is responsible for providing precisely this for the Spanish high-speed train, Velaro E (AVE S103), which operates between Madrid and Barcelona. (orig.)

  18. Short-Term Wind Speed Forecasting for Power System Operations

    KAUST Repository

    Zhu, Xinxin

    2012-04-01

    The emphasis on renewable energy and concerns about the environment have led to large-scale wind energy penetration worldwide. However, there are also significant challenges associated with the use of wind energy due to the intermittent and unstable nature of wind. High-quality short-term wind speed forecasting is critical to reliable and secure power system operations. This article begins with an overview of the current status of worldwide wind power developments and future trends. It then reviews some statistical short-term wind speed forecasting models, including traditional time series approaches and more advanced space-time statistical models. It also discusses the evaluation of forecast accuracy, in particular, the need for realistic loss functions. New challenges in wind speed forecasting regarding ramp events and offshore wind farms are also presented. © 2012 The Authors. International Statistical Review © 2012 International Statistical Institute.

  19. Wake flow characteristics at high wind speed

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Larsen, Torben J.; Larsen, Gunner Chr.

    2016-01-01

    Wake flow characteristic at high wind speeds is the main subject of this paper. Although the wake losses decrease at high wind speeds it has been found in a recent study that for multiple wake inflow the increase in loading due to wake effects are substantial even at wind speeds well above rated ...

  20. Next Generation Modeling Technology for High Speed Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent R&D associated with designing high speed rotorcraft has been greatly hampered by a lack of test data and confidence in predictions for rotors operating...

  1. High-speed optical signal processing using time lenses

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Guan, Pengyu

    2015-01-01

    This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle.......This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle....

  2. The Paris - Strasbourg high-speed line; Hochgeschwindigkeitsstrecke Paris - Strassburg

    Energy Technology Data Exchange (ETDEWEB)

    Brux, G.

    2007-07-01

    On 10th June 2007, TGV high-speed trains operated by French state railways SNCF, and ICE high-speed trains of Deutsche Bahn, will commence operations of France's eastern highspeed line Paris - Strasbourg, running services from Paris to Luxembourg, Frankfurt am Main and Stuttgart, and also to Basel and Zurich. As from the start of the new timetable on 9th December 2007, the service will also extend to Munich. The new high-speed line will shorten rail travels on these connections by several hours. (orig.)

  3. High speed imaging - An important industrial tool

    Science.gov (United States)

    Moore, Alton; Pinelli, Thomas E.

    1986-01-01

    High-speed photography, which is a rapid sequence of photographs that allow an event to be analyzed through the stoppage of motion or the production of slow-motion effects, is examined. In high-speed photography 16, 35, and 70 mm film and framing rates between 64-12,000 frames per second are utilized to measure such factors as angles, velocities, failure points, and deflections. The use of dual timing lamps in high-speed photography and the difficulties encountered with exposure and programming the camera and event are discussed. The application of video cameras to the recording of high-speed events is described.

  4. HIGH SPEED SHIP TOTAL RESISTANCE CALCULATION (AN EMPIRICAL STUDY

    Directory of Open Access Journals (Sweden)

    Dimas Endro W

    2014-02-01

    Full Text Available High speed design studies became very intense studies. One of the subject that can be explore is obtaining total resistace. A high speed ship has four stages of condition when she operates. Starting from low speed condition until developent of dinamics lift force. These four states that happened on high speed ship when she cuise on her operational speed, make a specific consideration on predicting her total resistance.  As high speed ship become more widely built and operate in Indonesia, the study of the state of art of high speed vessel  especially for obtaining total resistance has became more challenging In this paper is foccused on proposing an applicative methods for high speed resistance calculation based on savitsky method. Result which obtained form empirical study is compared to numerical software. Result of this study shows that there are no significant differences between empirical method and result form software application. Considering of sea margin would be effective to made the empirical method would be applicable. There is a 128,0812 KN of total resistance using empirical method, by considering sea margine factor, and a 128,512 KN of total resistance resulted form software calculation

  5. High-speed imaging in fluids

    NARCIS (Netherlands)

    Versluis, Michel

    2013-01-01

    High-speed imaging is in popular demand for a broad range of experiments in fluids. It allows for a detailed visualization of the event under study by acquiring a series of image frames captured at high temporal and spatial resolution. This review covers high-speed imaging basics, by defining

  6. High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

    Science.gov (United States)

    Taveniku, Mikael

    2013-01-01

    A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges. The current generation data recor - ders used within the VLBI community are aging, special-purpose machines that are both slow (do not meet today's requirements) and are very expensive to maintain and operate. Furthermore, they are not easily upgraded to take advantage of commercial technology development, and are not scalable to multiple 10s of Gbit/s data rates required by new applications. The innovation provides a softwaredefined, high-speed data recorder that is scalable with technology advances in the commercial space. It maximally utilizes current technologies without being locked to a particular hardware platform. The innovation also provides a cost-effective way of streaming large amounts of data from sensors to disk, enabling many applications to store raw sensor data and perform post and signal processing offline. This recording system will be applicable to many applications needing realworld, high-speed data collection, including electronic warfare, softwaredefined radar, signal history storage of multispectral sensors, development of autonomous vehicles, and more.

  7. Construction and operation of a high-speed, high-precision eye tracker for tight stimulus synchronization and real-time gaze monitoring in human and animal subjects

    Directory of Open Access Journals (Sweden)

    Reza Farivar

    2016-09-01

    Full Text Available Measurements of the fast and precise movements of the eye—critical to many vision, oculomotor, and animal behaviour studies—can be made non-invasively by video oculography. The protocol here describes the construction and operation of a research-grade video oculography system with 0.1° precision over the full typical viewing range at over 450Hz with tight synchronization with stimulus onset. The protocol consists of three stages: (1 system assembly, (2 calibration for both cooperative and for minimally cooperative subjects (e.g., animals or infants, and (3 gaze monitoring and recording.

  8. ACTS High-Speed VSAT Demonstrated

    Science.gov (United States)

    Tran, Quang K.

    1999-01-01

    The Advanced Communication Technology Satellite (ACTS) developed by NASA has demonstrated the breakthrough technologies of Ka-band transmission, spot-beam antennas, and onboard processing. These technologies have enabled the development of very small and ultrasmall aperture terminals (VSAT s and USAT's), which have capabilities greater than have been possible with conventional satellite technologies. The ACTS High Speed VSAT (HS VSAT) is an effort at the NASA Glenn Research Center at Lewis Field to experimentally demonstrate the maximum user throughput data rate that can be achieved using the technologies developed and implemented on ACTS. This was done by operating the system uplinks as frequency division multiple access (FDMA), essentially assigning all available time division multiple access (TDMA) time slots to a single user on each of two uplink frequencies. Preliminary results show that, using a 1.2-m antenna in this mode, the High Speed VSAT can achieve between 22 and 24 Mbps of the 27.5 Mbps burst rate, for a throughput efficiency of 80 to 88 percent.

  9. Green operations of belt conveyors by means of speed control

    NARCIS (Netherlands)

    He, D.; Pang, Y.; Lodewijks, G.

    2017-01-01

    Belt conveyors can be partially loaded due to the variation of bulk material flow loaded onto the conveyor. Speed control attempts to reduce the belt conveyor energy consumption and to enable the green operations of belt conveyors. Current research of speed control rarely takes the conveyor dynamics

  10. High-speed electrical motor evaluation

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-03

    Under this task, MTI conducted a general review of state-of-the-art high-speed motors. The purpose of this review was to assess the operating parameters, limitations and performance of existing motor designs, and to establish commercial sources for a motor compatible with the requirements of the Brayton-cycle system. After the motor requirements were established, a list of motor types, manufacturers and designs capable of achieving the requisite performance was compiled. This list was based on an in-house evaluation of designs. Following the establishment of these options, a technical evaluation of the designs selected was conducted. In parallel with their evaluations, MTI focused on the establishment of commercial sources.

  11. Application of variable speed operation on Francis Turbines

    Directory of Open Access Journals (Sweden)

    G. P. Heckelsmueller

    2015-04-01

    Full Text Available Francis turbines that are directly coupled to a synchronous generator operate at constant rotational speed around a design point characterized by a given water head, flow and guide vane aperture. When important changes occur in headwater level in power stations with large reservoirs, the turbines suffer a significant loss of efficiency. By applying variable speed technology it may be possible to adapt the runner speed and to operate with a higher efficiency over a wide range of water heads. This investigation is intended to reveal the possible benefits of using variable speed operation in regard to gains in efficiency and power output. Based on model test data it is possible to determine the characteristic curves of unitary speed and unitary flow of the respective prototype turbine for varying guide vane apertures. By varying rotor speed it is possible to maintain values that correspond to maximum efficiency. An analysis is made keeping guide vane aperture constant and introducing a proportionality factor of water flow to corresponding power output. The results show that for guide vane apertures and heads different from the design point, best efficiencies can be kept by adjusting rotor speed. At heads lower than the design head, significant efficiency gains can be achieved. Consequently, a significant proportion of the flow can be saved while generating the same amount of power.

  12. Switching speed limitations of high power IGBT modules

    DEFF Research Database (Denmark)

    Incau, Bogdan Ioan; Trintis, Ionut; Munk-Nielsen, Stig

    2015-01-01

    In this paper the switching speed limits of high power IGBT modules are investigated. The limitation of turn-on and turn-off switching speeds of the IGBTs are experimentally detected in a pulse tester. Different dc-bus stray inductances are considered, as well as the worst case scenario for the b......In this paper the switching speed limits of high power IGBT modules are investigated. The limitation of turn-on and turn-off switching speeds of the IGBTs are experimentally detected in a pulse tester. Different dc-bus stray inductances are considered, as well as the worst case scenario...... for the blocking dc-link voltage. Switching losses are analyzed upon a considerable variation of resistor value from turn-on gate driver side. Short circuit operations are investigated along with safe operating area for entire module to validate electrical capabilities under extreme conditions....

  13. High-speed modulation of vertical cavity surface emitting lasers

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Armendariz, M.G.; Choquette, K.D.; Lear, K.L.

    1998-03-01

    This report summarizes work on the development of high-speed vertical cavity surface emitting lasers (VCSELs) for multi-gigabit per second optical data communications applications (LDRD case number 3506.010). The program resulted in VCSELs that operate with an electrical bandwidth of 20 GHz along with a simultaneous conversion efficiency (DC to light) of about 20%. To achieve the large electrical bandwidth, conventional VCSELs were appropriately modified to reduce electrical parasitics and adapted for microwave probing for high-speed operation.

  14. High speed rail : challenges for the high speed rail project in Norway

    OpenAIRE

    Ringstad, Vidar

    2012-01-01

    This Master Thesis has focus on parts of the public transport system in Norway. The main topic in this thesis is: What variables must be calculated for the decision concerning the construction and implementation of the Norwegian High Speed Rail project, and how are the variables calculated? High Speed Rail does not have a single standard definition. High Speed Rail definition, given in the European Union definition, Directive 96/48 is suitable for many different systems of rolling stock...

  15. Scientific Visualization in High Speed Network Environments

    Science.gov (United States)

    Vaziri, Arsi; Kutler, Paul (Technical Monitor)

    1997-01-01

    In several cases, new visualization techniques have vastly increased the researcher's ability to analyze and comprehend data. Similarly, the role of networks in providing an efficient supercomputing environment have become more critical and continue to grow at a faster rate than the increase in the processing capabilities of supercomputers. A close relationship between scientific visualization and high-speed networks in providing an important link to support efficient supercomputing is identified. The two technologies are driven by the increasing complexities and volume of supercomputer data. The interaction of scientific visualization and high-speed networks in a Computational Fluid Dynamics simulation/visualization environment are given. Current capabilities supported by high speed networks, supercomputers, and high-performance graphics workstations at the Numerical Aerodynamic Simulation Facility (NAS) at NASA Ames Research Center are described. Applied research in providing a supercomputer visualization environment to support future computational requirements are summarized.

  16. Brandaris ultra high-speed imaging facility

    NARCIS (Netherlands)

    Lajoinie, Guillaume; de Jong, Nico; Versluis, Michel; Tsuji, K.

    2017-01-01

    High-speed imaging is in popular demand for a broad range of scientific applications, including fluid physics, and bubble and droplet dynamics. It allows for a detailed visualization of the event under study by acquiring a series of images captured at high temporal and spatial resolution. The

  17. High Speed Digital Camera Technology Review

    Science.gov (United States)

    Clements, Sandra D.

    2009-01-01

    A High Speed Digital Camera Technology Review (HSD Review) is being conducted to evaluate the state-of-the-shelf in this rapidly progressing industry. Five HSD cameras supplied by four camera manufacturers participated in a Field Test during the Space Shuttle Discovery STS-128 launch. Each camera was also subjected to Bench Tests in the ASRC Imaging Development Laboratory. Evaluation of the data from the Field and Bench Tests is underway. Representatives from the imaging communities at NASA / KSC and the Optical Systems Group are participating as reviewers. A High Speed Digital Video Camera Draft Specification was updated to address Shuttle engineering imagery requirements based on findings from this HSD Review. This draft specification will serve as the template for a High Speed Digital Video Camera Specification to be developed for the wider OSG imaging community under OSG Task OS-33.

  18. Survey of variable speed operation of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ola; Hylander, J.; Thorborg, K. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-01

    During the last five years the production and operation of variable-speed wind turbines have advanced from a few experimental machines to a serial production of at least 10 MW of installed capacity of variable speed machines per week. The rated power of serial wind turbines is today around 600 kW and for the prototypes up to 3000 kW. Variable speed operation of wind turbines can be obtained with several different types of electrical generating systems, such as synchronous generators with diode rectifiers and thyristor inverters or induction generators with IGBT-converters, for the wide speed range. For the narrow speed range the wound motor induction generator with a rotor cascade or a controlled rotor resistance is preferable. The development of permanent magnetic material and the reduction of costs of the power electronic components have opened a possibility of designing cost-effective wind turbines with a directly driven generator. Pitch control together with variable speed will make it possible to limit the power variation within a few percent, 2 to 5 %, of the rated power. 7 refs, 4 figs, 2 tabs

  19. High Speed Wireless Signal Generation and Demodulation

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Sambaraju, Rakesh; Zibar, Darko

    We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation.......We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation....

  20. High-speed dynamic-clamp interface

    Science.gov (United States)

    Yang, Yang; Adowski, Timothy; Ramamurthy, Bina; Neef, Andreas

    2015-01-01

    The dynamic-clamp technique is highly useful for mimicking synaptic or voltage-gated conductances. However, its use remains rare in part because there are few systems, and they can be expensive and difficult for less-experienced programmers to implement. Furthermore, some conductances (such as sodium channels) can be quite rapid or may have complex voltage sensitivity, so high speeds are necessary. To address these issues, we have developed a new interface that uses a common personal computer platform with National Instruments data acquisition and WaveMetrics IGOR to provide a simple user interface. This dynamic clamp implements leak and linear synaptic conductances as well as a voltage-dependent synaptic conductance and kinetic channel conductances based on Hodgkin-Huxley or Markov models. The speed of the system can be assayed using a testing mode, and currently speeds of >100 kHz (10 μs per cycle) are achievable with short latency and little jitter. PMID:25632075

  1. Crew Rostering for the High Speed Train

    NARCIS (Netherlands)

    R.M. Lentink (Ramon); M.A. Odijk; E. van Rijn

    2002-01-01

    textabstractAt the time of writing we entered the final stage of implementing the crew rostering system Harmony CDR to facilitate the planning of catering crews on board of the Thalys, the High Speed Train connecting Paris, Cologne, Brussels, Amsterdam, and Geneva. Harmony CDR optimally supports the

  2. Controllable High-Speed Rotation of Nanowires

    Science.gov (United States)

    Fan, D. L.; Zhu, F. Q.; Cammarata, R. C.; Chien, C. L.

    2005-06-01

    We report a versatile method for executing controllable high-speed rotation of nanowires by ac voltages applied to multiple electrodes. The rotation of the nanowires can be instantly switched on or off with precisely controlled rotation speed (to at least 1800 rpm), definite chirality, and total angle of rotation. We have determined the torque due to the fluidic drag force on nanowire of different lengths. We also demonstrate a micromotor using a rotating nanowire driving a dust particle into circular motion. This method has been used to rotate magnetic and nonmagnetic nanowires as well as carbon nanotubes.

  3. High speed, high current pulsed driver circuit

    Science.gov (United States)

    Carlen, Christopher R.

    2017-03-21

    Various technologies presented herein relate to driving a LED such that the LED emits short duration pulses of light. This is accomplished by driving the LED with short duration, high amplitude current pulses. When the LED is driven by short duration, high amplitude current pulses, the LED emits light at a greater amplitude compared to when the LED is driven by continuous wave current.

  4. Radiation-Tolerant High-Speed Camera

    Science.gov (United States)

    2017-03-01

    Radiation -Tolerant High-Speed Camera Esko Mikkola, Andrew Levy, Matt Engelman Alphacore, Inc. Tempe, AZ 85281 Abstract: As part of an... radiation -hardened CMOS image sensor and camera system. Radiation -hardened cameras with frame rates as high as 10 kfps and resolution of 1Mpixel are not...camera solution that is under development with a similar architecture. It also includes a brief description of the radiation -hardened camera that

  5. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.

    1999-03-01

    Secondary containment for high speed rotating machinery, such as a centrifuge, is extremely important for operating personnel safety. Containment techniques can be very costly, ungainly and time consuming to construct. A novel containment concept is introduced which is fabricated out of modular sections of polycarbonate glazed into a Unistrut metal frame. A containment study for a high speed centrifuge is performed which includes the development of parameters for secondary containment design. The Unistrut/polycarbonate shield framing concept is presented including design details and proof testing procedures. The economical fabrication and modularity of the design indicates a usefulness for this shielding system in a wide variety of containment scenarios.

  6. PMSM sensorless control with separate control strategies and smooth switch from low speed to high speed.

    Science.gov (United States)

    Chen, SiYi; Luo, Ying; Pi, YouGuo

    2015-09-01

    This paper proposes a smooth switching scheme with separate control strategies on low speed mode and high speed mode for permanent magnet synchronous motor (PMSM) sensorless control to improve the overall performance in full speed range. Constant voltage/frequency tuning method is used on low speed mode because the rotor position can hardly be estimated precisely at low speed. Along with the increasing speed, the control strategy can be switched to high speed mode smoothly when current and speed meet the given requirements. In this high speed mode, the current tracking with a sliding mode observer (SMO) and speed tracking with a sliding mode controller (SMC) are handled, respectively. Experimental demonstration is presented to show the desired performance in full speed range of the PMSM sensorless control using the proposed control scheme in this paper. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  7. CMOS Image Sensors for High Speed Applications.

    Science.gov (United States)

    El-Desouki, Munir; Deen, M Jamal; Fang, Qiyin; Liu, Louis; Tse, Frances; Armstrong, David

    2009-01-01

    Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4∼5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps).

  8. CMOS Image Sensors for High Speed Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen

    2009-01-01

    Full Text Available Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps.

  9. Developing course lecture notes on high-speed rail.

    Science.gov (United States)

    2017-07-15

    1. Introduction a. World-wide Development of High-Speed Rail (Japan, Europe, China) b. High-speed Rail in the U.S. 2. High-Speed Rail Infrastructure a. Geometric Design of High Speed Rail i. Horizontal Curve ii. Vertical Curve iii. Grade and Turnout ...

  10. Gas turbine for high speed trains

    Energy Technology Data Exchange (ETDEWEB)

    Chenard, J.-L. [Turbomeca (France)

    1994-12-31

    This presentation will show how the gas turbine engines can be the right compromise to face the challenges raised by the demand for high speed trains through out the world. From the steam locomotive still in use in China to the TGV or ICE in Europe and Shinkensen in Japan able to run at more than 300 kms/hour, the modes of traction for trains have been greatly improved during the last fifty years. Even more faster trains are under studies for the future with the magnetic levitation system. Three main propulsion system, diesel, electric and gas turbines are actually competing in the high speed train market. They will have to comply with the new environmental regulations, better efficiency and customers` requirements for the developed countries, and with the necessity to use the existing tracks for most of the applications

  11. High-speed inline holographic Stokesmeter imaging.

    Science.gov (United States)

    Liu, Xue; Heifetz, Alexander; Tseng, Shih C; Shahriar, M S

    2009-07-01

    We demonstrate a high-speed inline holographic Stokesmeter that consists of two liquid crystal retarders and a spectrally selective holographic grating. Explicit choices of angles of orientation for the components in the inline architecture are identified to yield higher measurement accuracy than the classical architecture. We show polarimetric images of an artificial scene produced by such a Stokesmeter, demonstrating the ability to identify an object not recognized by intensity-only imaging systems.

  12. Unsteady Flow Simulation of High-speed Turbopumps

    Science.gov (United States)

    Kiris, Cetin C.; Kwak, dochan; Chan, William; Housman, Jeffrey A.

    2006-01-01

    Computation of high-speed hydrodynamics requires high-fidelity simulation to resolve flow features involving transient flow, cavitation, tip vortex and multiple scales of unsteady fluctuations. One example of this type in aerospace is related to liquid-fueled rocket turbopump. Rocket turbopumps operate under severe conditions at very high rotational speeds typically at thousands of rpm. For example, the Shuttle orbiter low-pressure-fuel-turbopump creates transient flow features associated with reverse flows, tip clearance effects, secondary flows, vortex shedding, junction flows, and cavitation effects. Flow unsteadiness originating from the orbiter Low-Pressure-Fuel-Turbopump (LPFTP) inducer is one of the major contributors to the high frequency cyclic loading that results in high cycle fatigue damage to the flow liners just upstream of the LPFTP. The reverse flow generated at the tip of the inducer blades travels upstream and interacts with the bellows cavity. Simulation procedure for this type high-speed hydrodynamic problems requires a method for quantifying multi-scale and multi-phase flow as well as an efficient high-end computing strategy. The current paper presents a high-fidelity computational procedure for unsteady hydrodynamic problems using a high-speed liquid-fueled rocket turbopump.

  13. High-speed cinematography of compressible mixing layers

    Science.gov (United States)

    Mahadevan, R.; Loth, Eric

    1994-07-01

    Experiments are performed using high-speed film cinematography to temporally resolve compressible planar mixing layer structures using shadowgraphs and planar light sheet visualization. The technique is relatively inexpensive and allows multiple images. The time-dependent shadowgraph and Mie scattering images are documented with a rotating mirror camera operating at approximately 350 kHz. The results show the presence of large scale structures in the mixing layer which flatten as they convect downstream. Both spatial and temporal covariances have been obtained through digital image processing which yield, on average, elliptical structures with convective speeds above the isentropic prediction, and non-isotropic streamwise and transverse scalar transport fluctuations.

  14. All aboard for high-speed rail

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D.

    1996-09-01

    A sleek, bullet-nosed train whizzing across the countryside is a fairly common sight in many nations. Since the Train a Grande Vitesse (TGV)--the record-setting ``train with great speed``--was introduced in France in 1981, Germany, Japan, and other countries have joined the high-speed club. In addition, the Eurostar passenger train, which travels between Great Britain and France through the Channel Tunnel, can move at 186 miles per hour once it reaches French tracks. Despite the technology`s growth elsewhere, rapid rail travel has not been seen on US shores beyond a few test runs by various manufacturers. Before the end of the century, however, American train spotters will finally be able to see some very fast trains here too. In March, Washington, DC-based Amtrak announced the purchase of 18 American Flyer high-speed train sets for the Northeast Corridor, which stretches from Boston through new York to the nation`s capital. Furthermore, Florida will get its own system by 2004, and other states are now taking a look at the technology. The American Flyer--designed by Montreal-based Bombardier and TGV manufacturer GEC Alsthom Transport in Paris--should venture onto US rails by 1999. Traveling at up to 150 miles per hour, the American Flyer will cut the New York-Boston run from 4 1/2 hours to 3 hours and reduce New York-Washington trip time from 3 hours to less than 2 3/4. Amtrak hopes the new trains and better times will earn it a greater share of travelers from air shuttles and perhaps from Interstate 95. This article describes how technologies that tilt railcars and propel the world`s fastest trains will be merged into one train set for the American Flyer, Amtrak`s first trip along high-speed rails.

  15. Ultra-high-speed optical and electronic distributed devices

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.

    1995-08-01

    This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

  16. Standard Operating Procedure for the Grinding and Extraction of Lead in Paint using Nitric Acid and a Rotor/Stator System Powered by a High Speed Motor

    Science.gov (United States)

    This Standard Operating Procedure (SOP) describes a new, rapid, and relatively inexpensive one step procedure which grinds the paint samples removed from the substrate and simultaneously quantitatively extracts the Pb from the paint in only one step in preparation for quantitativ...

  17. Noise in the passenger cars of high-speed trains.

    Science.gov (United States)

    Hong, Joo Young; Cha, Yongwon; Jeon, Jin Yong

    2015-12-01

    The aim of this study is to investigate the effects of both room acoustic conditions and spectral characteristics of noises on acoustic discomfort in a high-speed train's passenger car. Measurement of interior noises in a high-speed train was performed when the train was operating at speeds of 100 km/h and 300 km/h. Acoustic discomfort caused by interior noises was evaluated by paired comparison methods based on the variation of reverberation time (RT) in a passenger car and the spectral differences in interior noises. The effect of RT on acoustic discomfort was not significant, whereas acoustic discomfort significantly varied depending on spectral differences in noise. Acoustic discomfort increased with increment of the sound pressure level (SPL) ratio at high frequencies, and variation in high-frequency noise components were described using sharpness. Just noticeable differences of SPL with low- and high-frequency components were determined to be 3.7 and 2.9 dB, respectively. This indicates that subjects were more sensitive to differences in SPLs at the high-frequency range than differences at the low-frequency range. These results support that, for interior noises, reduction in SPLs at high frequencies would significantly contribute to improved acoustic quality in passenger cars of high-speed trains.

  18. Network Based High Speed Product Innovation

    DEFF Research Database (Denmark)

    Lindgren, Peter

    In the first decade of the 21st century, New Product Development has undergone major changes in the way NPD is managed and organised. This is due to changes in technology, market demands, and in the competencies of companies. As a result NPD organised in different forms of networks is predicted...... to be of ever-increasing importance to many different kinds of companies. This happens at the same times as the share of new products of total turnover and earnings is increasing at unprecedented speed in many firms and industries. The latter results in the need for very fast innovation and product development...... - a need that can almost only be resolved by organising NPD in some form of network configuration. The work of Peter Lindgren is on several aspects of network based high speed product innovation and contributes to a descriptive understanding of this phenomenon as well as with normative theory on how NPD...

  19. High-speed and high-fidelity system and method for collecting network traffic

    Science.gov (United States)

    Weigle, Eric H [Los Alamos, NM

    2010-08-24

    A system is provided for the high-speed and high-fidelity collection of network traffic. The system can collect traffic at gigabit-per-second (Gbps) speeds, scale to terabit-per-second (Tbps) speeds, and support additional functions such as real-time network intrusion detection. The present system uses a dedicated operating system for traffic collection to maximize efficiency, scalability, and performance. A scalable infrastructure and apparatus for the present system is provided by splitting the work performed on one host onto multiple hosts. The present system simultaneously addresses the issues of scalability, performance, cost, and adaptability with respect to network monitoring, collection, and other network tasks. In addition to high-speed and high-fidelity network collection, the present system provides a flexible infrastructure to perform virtually any function at high speeds such as real-time network intrusion detection and wide-area network emulation for research purposes.

  20. High speed flux feedback for tuning a universal field oriented controller capable of operating in direct and indirect field orientation modes

    Science.gov (United States)

    De Doncker, R.W.A.A.

    1992-09-01

    The direct (d) and quadrature (q) components of flux, as sensed by flux sensors or determined from voltage and current measurements in a direct field orientation scheme, are processed rapidly and accurately to provide flux amplitude and angular position values for use by the vector rotator of a universal field-oriented (UFO) controller. Flux amplitude (linear or squared) is provided as feedback to tune the UFO controller for operation in direct and indirect field orientation modes and enables smooth transitions from one mode to the other. 3 figs.

  1. Operational amplifier speed and accuracy improvement analog circuit design with structural methodology

    CERN Document Server

    Ivanov, Vadim V

    2004-01-01

    Operational Amplifier Speed and Accuracy Improvement proposes a new methodology for the design of analog integrated circuits. The usefulness of this methodology is demonstrated through the design of an operational amplifier. This methodology consists of the following iterative steps: description of the circuit functionality at a high level of abstraction using signal flow graphs; equivalent transformations and modifications of the graph to the form where all important parameters are controlled by dedicated feedback loops; and implementation of the structure using a library of elementary cells. Operational Amplifier Speed and Accuracy Improvement shows how to choose structures and design circuits which improve an operational amplifier's important parameters such as speed to power ratio, open loop gain, common-mode voltage rejection ratio, and power supply rejection ratio. The same approach is used to design clamps and limiting circuits which improve the performance of the amplifier outside of its linear operat...

  2. Quiet High Speed Fan II (QHSF II): Final Report

    Science.gov (United States)

    Kontos, Karen; Weir, Don; Ross, Dave

    2012-01-01

    This report details the aerodynamic, mechanical, structural design and fabrication of a Honey Engines Quiet High Speed Fan II (lower hub/tip ratio and higher specific flow than the Baseline I fan). This fan/nacelle system incorporates features such as advanced forward sweep and an advanced integrated fan/fan exit guide vane design that provides for the following characteristics: (1) Reduced noise at supersonic tip speeds, in comparison to current state-of-the-art fan technology; (2) Improved aeroelastic stability within the anticipated operating envelope; and (3) Aerodynamic performance consistent with current state-of-the-art fan technology. This fan was fabricated by Honeywell and tested in the NASA Glenn 9- by 15-Ft Low Speed Wind Tunnel for aerodynamic, aeromechanical, and acoustic performance.

  3. An Alternative Approach for High Speed Railway Carrying Capacity Calculation Based on Multiagent Simulation

    Directory of Open Access Journals (Sweden)

    Mo Gao

    2016-01-01

    Full Text Available It is a multiobjective mixed integer programming problem that calculates the carrying capacity of high speed railway based on mathematical programming method. The model is complex and difficult to solve, and it is difficult to comprehensively consider the various influencing factors on the train operation. The multiagent theory is employed to calculate high speed railway carrying capacity. In accordance with real operations of high speed railway, a three-layer agent model is developed to simulate the operating process of high speed railway. In the proposed model, railway network agent, line agent, station agent, and train agent are designed, respectively. To validate the proposed model, a case study is performed for Beijing–Shanghai high speed railway by using NetLogo software. The results are consistent with the actual data, which implies that the proposed multiagent method is feasible to calculate the carrying capacity of high speed railway.

  4. High Speed White Dwarf Asteroseismology with the Herty Hall Cluster

    Science.gov (United States)

    Gray, Aaron; Kim, A.

    2012-01-01

    Asteroseismology is the process of using observed oscillations of stars to infer their interior structure. In high speed asteroseismology, we complete that by quickly computing hundreds of thousands of models to match the observed period spectra. Each model on a single processor takes five to ten seconds to run. Therefore, we use a cluster of sixteen Dell Workstations with dual-core processors. The computers use the Ubuntu operating system and Apache Hadoop software to manage workloads.

  5. High-speed multispectral confocal biomedical imaging.

    Science.gov (United States)

    Carver, Gary E; Locknar, Sarah A; Morrison, William A; Ramanujan, V Krishnan; Farkas, Daniel L

    2014-03-01

    A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues.

  6. Theory Of High-Speed Stereophotogrammetry

    Science.gov (United States)

    Hongxun, Song; Junren, Chen

    1989-06-01

    The general equations of direct linear transformation (DLT) are derived according to the actual process of high-speed stereophotogrammetry. The equations are not only applicable to the ordinary photographic system, but also to the photographic system with reflectors or stereo-reflectors. The equations are also suitable to the enlarged, copied and projected measurements of photographic film. The linear and non-linear errors in photogrammetric process can be corrected. Finally, the equations of right angle intersection photogrammetry are given and the merits and demerits of this method are discussed.

  7. Study of high-speed civil transports

    Science.gov (United States)

    1989-01-01

    A systems study to identify the economic potential for a high-speed commercial transport (HSCT) has considered technology, market characteristics, airport infrastructure, and environmental issues. Market forecasts indicate a need for HSCT service in the 2000/2010 time frame conditioned on economic viability and environmental acceptability. Design requirements focused on a 300 passenger, 3 class service, and 6500 nautical mile range based on the accelerated growth of the Pacific region. Compatibility with existing airports was an assumed requirement. Mach numbers between 2 and 25 were examined in conjunction with the appropriate propulsion systems, fuels, structural materials, and thermal management systems. Aircraft productivity was a key parameter with aircraft worth, in comparison to aircraft price, being the airline-oriented figure of merit. Aircraft screening led to determination that Mach 3.2 (TSJF) would have superior characteristics to Mach 5.0 (LNG) and the recommendation that the next generation high-speed commercial transport aircraft use a kerosene fuel. The sensitivity of aircraft performance and economics to environmental constraints (e.g., sonic boom, engine emissions, and airport/community noise) was identified together with key technologies. In all, current technology is not adequate to produce viable HSCTs for the world marketplace. Technology advancements must be accomplished to meet environmental requirements (these requirements are as yet undetermined for sonic boom and engine emissions). High priority is assigned to aircraft gross weight reduction which benefits both economics and environmental aspects. Specific technology requirements are identified and national economic benefits are projected.

  8. Operation and performance evaluation of high-speed filter using porous non-woven filamentous fibre for the treatment of turbid water.

    Science.gov (United States)

    Niu, Siping; Park, Kisoo; Yu, Jianghua; Kim, Youngchul

    2016-01-01

    This study was carried out to identify the filter performance of fibre filter module treating high-turbidity water at extremely high filtration rates (1000-2500 m/day). The effects of filter aid chemical (polyaluminium chloride (PAC)), filtration rate and particles size on filter performance were investigated. It was found that PAC was a crucial factor influencing the separation process. Even though the optimum PAC dose for the raw water with turbidity of 50 nephelometric turbidity units (NTU) was 0.5 mg/L, the turbidity removal efficiencies were similar as the raw water turbidity was no more than 50 NTU. As expected, the filter performance was negatively affected by the increased filtration rate. However, the turbidity removal efficiency at an extremely high filtration rate still was amazing and attractive (∼80% at 2500 m/day). Moreover, the D50 and uniformity coefficient of the particles in raw water were not the factors greatly affecting the filter performance. The empirical model for the filter processes of granular filters did not work; therefore, an empirical model towards fibre filters at a high flow rate was suggested, which can be used to predict the treatment performance.

  9. Laser beam welding by high-speed beam deflection; Laserstrahlschweissen durch High-Speed-Strahlbewegung

    Energy Technology Data Exchange (ETDEWEB)

    Klotzbach, A.; Morgenthal, L.; Beyer, E. [Fraunhofer-Institut fuer Werkstoff- und Strahltechnik, Dresden (Germany)

    1999-04-01

    The beam deflection system developed at Fraunhofer IWS can be used for rapid moving of a high power laser beam over the workpiece surface. Therefore it is possible to scan even rather small paths with high speed. The system contents two galvanometer scanner with specially designed lightweight mirrors in combination with a beam focusing unit. (Fig. 1). The high-speed welding of contours with small diameter is favorably done with both focusing optics and workpiece fixed (Fig. 2,3). Thus all notorius problems of conventional handling systems, as limited velocity and accuracy resulting from the inertia of the moved focusing head or workpiece, vanish. (orig.)

  10. Automatic in-process chatter avoidance in the high-speed milling process

    NARCIS (Netherlands)

    Dijk, N.J.M. van; Doppenberg, E.J.J.; Faassen, R.P.H.; Wouw, N. van de; Oosterling, J.A.J.; Nijmeijer, H.

    2010-01-01

    High-speed milling is often used in industry to maximize productivity of the manufacturing of high-technology components, such as aeronautical components, mold, and dies. The occurrence of chatter highly limits the efficiency and accuracy of high-speed milling operations. In this paper, two control

  11. Limitation of Hot-Carrier Generated Heat Dissipation on the Frequency of Operation and Reliability of Novel Nitride-Based High-Speed HFETs

    Science.gov (United States)

    2012-01-18

    Matulionis, „Hot-electron transport in graded AlGaN alloys“ COST Action MP0805: training school: Izmir, Turkey, April 12-14, 2011. Distribution A...Matulionis, I. Matulionien, “Hot-phonon lifetime in a modulation- doped AlInAs/GaInAs/AlInAs/InP”, Semiconductor Science and Technology 20 (2), 109–114...in high-power microwave HEMT and FET channels“, in „Advanced semiconductor materials and devices research - SiC and III-Nitrides”, Ho-Young Cha, ed

  12. High speed electromechanical response of ionic microactuators

    Science.gov (United States)

    Maziz, Ali; Plesse, Cedric; Soyer, Caroline; Cattan, Eric; Vidal, Frederic

    2015-04-01

    This paper presents the synthesis and characterization of thin and ultra-fast conducting polymer microactuators which can operate in the open air. Compared to all previous existing electronic conducting polymer based microactuators, this approach deals with the synthesis of robust interpenetrating polymer networks (IPNs) combined with a spincoating technique in order to tune and drastically reduce the thickness of conducting IPN microactuators using a so-called "trilayer" configuration. Patterning of electroactive materials has been performed with existing technologies, such as standard photolithography and dry etching. The smallest air-operating microbeam actuator based on conducting polymer is then described with dimensions as low as 160x30x6 μm3. Under electrical stimulation the translations of small ion motion into bending deformations are used as tools to demonstrate that small ion vibrations can still occur at frequency as several hundreds of Hz. Conducting IPN microactuators are then promising candidates to develop new MEMS combining downscaling, softness, low driving voltage, and fast response speed.

  13. Flexible, High-Speed CdSe Nanocrystal Integrated Circuits.

    Science.gov (United States)

    Stinner, F Scott; Lai, Yuming; Straus, Daniel B; Diroll, Benjamin T; Kim, David K; Murray, Christopher B; Kagan, Cherie R

    2015-10-14

    We report large-area, flexible, high-speed analog and digital colloidal CdSe nanocrystal integrated circuits operating at low voltages. Using photolithography and a newly developed process to fabricate vertical interconnect access holes, we scale down device dimensions, reducing parasitic capacitances and increasing the frequency of circuit operation, and scale up device fabrication over 4 in. flexible substrates. We demonstrate amplifiers with ∼7 kHz bandwidth, ring oscillators with <10 μs stage delays, and NAND and NOR logic gates.

  14. High-speed analog CMOS pipeline system

    Science.gov (United States)

    Möschen, J.; Caldwell, A.; Hervas, L.; Hosticka, B.; Kötz, U.; Sippach, B.

    1990-03-01

    We present a switched-capacitor readout system for high speed analog signals. It consists of a 10 MHz four-channel delay-line chip with 58 samples per channel and a 12 channel buffer chip with a sampling rate of 1 MHz and a depth of nine samples. In addition the buffer chip includes an analog multiplexer with 25 inputs for the buffer channels and for 13 additional unbuffered signals. Both chips have been fabricated in CMOS-technology and will be used for the readout of the ZEUS high resolution calorimeter. The circuit and chip concept will be presented and some design optimizations will be discussed. Measurements from integrated prototypes will be given including some experimental data from irradiated chips.

  15. High Speed Imaging of Cavitation around Dental Ultrasonic Scaler Tips.

    Science.gov (United States)

    Vyas, Nina; Pecheva, Emilia; Dehghani, Hamid; Sammons, Rachel L; Wang, Qianxi X; Leppinen, David M; Walmsley, A Damien

    2016-01-01

    Cavitation occurs around dental ultrasonic scalers, which are used clinically for removing dental biofilm and calculus. However it is not known if this contributes to the cleaning process. Characterisation of the cavitation around ultrasonic scalers will assist in assessing its contribution and in developing new clinical devices for removing biofilm with cavitation. The aim is to use high speed camera imaging to quantify cavitation patterns around an ultrasonic scaler. A Satelec ultrasonic scaler operating at 29 kHz with three different shaped tips has been studied at medium and high operating power using high speed imaging at 15,000, 90,000 and 250,000 frames per second. The tip displacement has been recorded using scanning laser vibrometry. Cavitation occurs at the free end of the tip and increases with power while the area and width of the cavitation cloud varies for different shaped tips. The cavitation starts at the antinodes, with little or no cavitation at the node. High speed image sequences combined with scanning laser vibrometry show individual microbubbles imploding and bubble clouds lifting and moving away from the ultrasonic scaler tip, with larger tip displacement causing more cavitation.

  16. Performance analysis of WAVE communication under high-speed driving

    Directory of Open Access Journals (Sweden)

    Bo-young Kang

    2017-12-01

    Full Text Available Although WAVE (Wireless Access in Vehicular Environments is a technology designed for the high-speed mobile environments, WAVE communication performance in a real road environment is highly dependent on the surrounding environments such as moving vehicles, road shape, and topography. In particular, when a vehicle moves at high speed, the location of the vehicle and its proximity to the road-side device are rapidly changed and thus affect communication performance. Accordingly, we build a performance evaluation system based on the WAVE-LTE network cooperative operation. We also analyzed the performance differences based on external environmental factors, such as information volume and velocity, from the data acquired through actual vehicle tests.

  17. Using a High-Speed Camera to Measure the Speed of Sound

    Science.gov (United States)

    Hack, William Nathan; Baird, William H.

    2012-01-01

    The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

  18. High-speed ground transportation noise and vibration impact assessment.

    Science.gov (United States)

    2012-09-01

    This report is the second edition of a guidance manual originally issued in 2005, which presents procedures for predicting and assessing noise and vibration impacts of high-speed ground transportation projects. Projects involving high-speed trains us...

  19. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of this proposal is to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight,...

  20. South Carolina southeast high speed rail corridor improvement study

    Science.gov (United States)

    2001-02-01

    The Southeast Rail Corridor was originally designated as a high-speed corridor in Section 1010 of the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991. More specifically, it involved the high-speed grade-crossing improvement program o...

  1. High-speed and intercity passenger rail testing strategy.

    Science.gov (United States)

    2013-05-01

    This high-speed and intercity passenger rail (HSIPR) testing strategy addresses the requirements for testing of high-speed train sets and technology before introduction to the North American railroad system. The report documents the results of a surv...

  2. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight, low voltage beam...

  3. Double Helical Gear Performance Results in High Speed Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles

    2010-01-01

    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  4. Controlling high speed automated transport network operations

    NARCIS (Netherlands)

    de Feijter, R.

    2006-01-01

    This thesis presents a framework for the control of automated guided vehicles (AGVs). The framework implements the transport system as a community of cooperating agents. Besides the architecture and elements of the framework a wide range of infrastructure scene templates is described. These scene

  5. HIGH SPEED KERR CELL FRAMING CAMERA

    Science.gov (United States)

    Goss, W.C.; Gilley, L.F.

    1964-01-01

    The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

  6. High Speed/ Low Effluent Process for Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    M. Clark Dale

    2006-10-30

    n this project, BPI demonstrated a new ethanol fermentation technology, termed the High Speed/ Low Effluent (HS/LE) process on both lab and large pilot scale as it would apply to wet mill and/or dry mill corn ethanol production. The HS/LE process allows very rapid fermentations, with 18 to 22% sugar syrups converted to 9 to 11% ethanol ‘beers’ in 6 to 12 hours using either a ‘consecutive batch’ or ‘continuous cascade’ implementation. This represents a 5 to 8X increase in fermentation speeds over conventional 72 hour batch fermentations which are the norm in the fuel ethanol industry today. The ‘consecutive batch’ technology was demonstrated on a large pilot scale (4,800 L) in a dry mill corn ethanol plant near Cedar Rapids, IA (Xethanol Biofuels). The pilot demonstrated that 12 hour fermentations can be accomplished on an industrial scale in a non-sterile industrial environment. Other objectives met in this project included development of a Low Energy (LE) Distillation process which reduces the energy requirements for distillation from about 14,000 BTU/gal steam ($0.126/gal with natural gas @ $9.00 MCF) to as low as 0.40 KW/gal electrical requirements ($0.022/gal with electricity @ $0.055/KWH). BPI also worked on the development of processes that would allow application of the HS/LE fermentation process to dry mill ethanol plants. A High-Value Corn ethanol plant concept was developed to produce 1) corn germ/oil, 2) corn bran, 3) ethanol, 4) zein protein, and 5) nutritional protein, giving multiple higher value products from the incoming corn stream.

  7. High-Speed Low-Jitter Frequency Multiplication in CMOS

    NARCIS (Netherlands)

    van de Beek, R.C.H.

    2004-01-01

    This thesis deals with high-speed Clock and Frequency Multiplication. The term `high-speedù applies to both the output and the reference frequency of the multiplier. Much emphasis is placed on analysis and optimization of the total timing inaccuracies, and on implementing a high-speed feedback

  8. Videokymography : High-speed line scanning of vocal fold vibration

    NARCIS (Netherlands)

    Svec, JG; Schutte, HK

    A digital technique for high-speed visualization of vibration, called videokymography, was developed and applied to the vocal folds. The system uses a modified video camera able to work in two modes: high-speed (nearly 8,000 images/s) and standard (50 images/s in CCIR norm). In the high-speed mode,

  9. High-speed gears for gas turbine drive

    Energy Technology Data Exchange (ETDEWEB)

    Kane, J.

    1995-06-01

    Recently, Lufkin Industries, Power Transmission Div., full-load tested a high-speed gear designed to couple a 50 Hz electric power generator to a GE LM6000 gas turbine for a power generation project in Australia. The gear is rated 52.2 MW to match the output of the LM6000 gas turbine believed to be one of the largest gear testing operations for this type and size of gear. Each gear drive manufactured by Lufkin is full-speed tested to verify its performance. Tests performed on high-speed units duplicate field conditions, as closely as possible, in order to verify critical speed analysis results and new bearing designs, if used. Lufkin also tests design techniques used in the development of new products. The finite element analysis performed to predict housing deflection in the thrust bearing area of a new extruder driveline was verified by testing of a prototype unit housing. Recently, housing structure stiffness and natural frequencies were predicted and verified on the test stand for some 50 MW vertically offset gear units. A complete data acquisition system is used to gather data from bearing, inlet and drain temperature monitoring points. The temperature monitoring system will accommodate type T,K,J, and E thermocouples and platinum and nickel RTDs.

  10. FPGA Flash Memory High Speed Data Acquisition

    Science.gov (United States)

    Gonzalez, April

    2013-01-01

    The purpose of this research is to design and implement a VHDL ONFI Controller module for a Modular Instrumentation System. The goal of the Modular Instrumentation System will be to have a low power device that will store data and send the data at a low speed to a processor. The benefit of such a system will give an advantage over other purchased binary IP due to the capability of allowing NASA to re-use and modify the memory controller module. To accomplish the performance criteria of a low power system, an in house auxiliary board (Flash/ADC board), FPGA development kit, debug board, and modular instrumentation board will be jointly used for the data acquisition. The Flash/ADC board contains four, 1 MSPS, input channel signals and an Open NAND Flash memory module with an analog to digital converter. The ADC, data bits, and control line signals from the board are sent to an Microsemi/Actel FPGA development kit for VHDL programming of the flash memory WRITE, READ, READ STATUS, ERASE, and RESET operation waveforms using Libero software. The debug board will be used for verification of the analog input signal and be able to communicate via serial interface with the module instrumentation. The scope of the new controller module was to find and develop an ONFI controller with the debug board layout designed and completed for manufacture. Successful flash memory operation waveform test routines were completed, simulated, and tested to work on the FPGA board. Through connection of the Flash/ADC board with the FPGA, it was found that the device specifications were not being meet with Vdd reaching half of its voltage. Further testing showed that it was the manufactured Flash/ADC board that contained a misalignment with the ONFI memory module traces. The errors proved to be too great to fix in the time limit set for the project.

  11. Design and Analysis of High Speed Capacitive Pipeline DACs

    OpenAIRE

    Duong, Quoc-Tai; Dabrowski, Jerzy; Alvandpour, Atila

    2014-01-01

    Design of a high speed capacitive digital-to-analog converter (SC DAC) is presented for 65 nm CMOS technology. SC pipeline architecture is used followed by an output driver. For GHz frequency operation with output voltage swing suitable for wireless applications (300 mVpp) the DAC performance is shown to be limited by the capacitor array imperfections. While it is possible to design a highly linear output driver with HD3 < -70 dB and HD2 < -90 dB over 0.55 GHz band as we show, the maxi...

  12. Fusion: ultra-high-speed and IR image sensors

    Science.gov (United States)

    Etoh, T. Goji; Dao, V. T. S.; Nguyen, Quang A.; Kimata, M.

    2015-08-01

    Most targets of ultra-high-speed video cameras operating at more than 1 Mfps, such as combustion, crack propagation, collision, plasma, spark discharge, an air bag at a car accident and a tire under a sudden brake, generate sudden heat. Researchers in these fields require tools to measure the high-speed motion and heat simultaneously. Ultra-high frame rate imaging is achieved by an in-situ storage image sensor. Each pixel of the sensor is equipped with multiple memory elements to record a series of image signals simultaneously at all pixels. Image signals stored in each pixel are read out after an image capturing operation. In 2002, we developed an in-situ storage image sensor operating at 1 Mfps 1). However, the fill factor of the sensor was only 15% due to a light shield covering the wide in-situ storage area. Therefore, in 2011, we developed a backside illuminated (BSI) in-situ storage image sensor to increase the sensitivity with 100% fill factor and a very high quantum efficiency 2). The sensor also achieved a much higher frame rate,16.7 Mfps, thanks to the wiring on the front side with more freedom 3). The BSI structure has another advantage that it has less difficulties in attaching an additional layer on the backside, such as scintillators. This paper proposes development of an ultra-high-speed IR image sensor in combination of advanced nano-technologies for IR imaging and the in-situ storage technology for ultra-highspeed imaging with discussion on issues in the integration.

  13. Cleveland-Columbus-Cincinnati high-speed rail study

    Science.gov (United States)

    2001-07-01

    In the past five years, the evaluation of different high-speed rail (HSR) studies in the Midwest has resulted in a realization that high speed rail, with speeds greater than 110 miles per hour, is too expensive in the short term to be implemented in ...

  14. High speed turning of compacted graphite iron using controlled modulation

    Science.gov (United States)

    Stalbaum, Tyler Paul

    Compacted graphite iron (CGI) is a material which emerged as a candidate material to replace cast iron (CI) in the automotive industry for engine block castings. Its thermal and mechanical properties allow the CGI-based engines to operate at higher cylinder pressures and temperatures than CI-based engines, allowing for lower fuel emissions and increased fuel economy. However, these same properties together with the thermomechanical wear mode in the CGI-CBN system result in poor machinability and inhibit CGI from seeing wide spread use in the automotive industry. In industry, machining of CGI is done only at low speeds, less than V = 200 m/min, to avoid encountering rapid wear of the cutting tools during cutting. Studies have suggested intermittent cutting operations such as milling suffer less severe tool wear than continuous cutting. Furthermore, evidence that a hard sulfide layer which forms over the cutting edge in machining CI at high speeds is absent during machining CGI is a major factor in the difference in machinability of these material systems. The present study addresses both of these issues by modification to the conventional machining process to allow intermittent continuous cutting. The application of controlled modulation superimposed onto the cutting process -- modulation-assisted machining (MAM) -- is shown to be quite effective in reducing the wear of cubic boron nitride (CBN) tools when machining CGI at high machining speeds (> 500 m/min). The tool life is at least 20 times greater than found in conventional machining of CGI. This significant reduction in wear is a consequence of reduction in the severity of the tool-work contact conditions with MAM. The propensity for thermochemical wear of CBN is thus reduced. It is found that higher cutting speed (> 700 m/min) leads to lower tool wear with MAM. The MAM configuration employing feed-direction modulation appears feasible for implementation at high speeds and offers a solution to this challenging

  15. L1 Adaptive Manoeuvring Control of Unmanned High-speed Water Craft

    DEFF Research Database (Denmark)

    Svendsen, Casper H.; Holck, Niels Ole; Galeazzi, Roberto

    2012-01-01

    This work addresses the issue of designing an adaptive robust control system to govern the steering of a high speed unmanned personal watercraft (PWC) maintaining equal performance across the craft’s envelope of operation. The maneuvering dynamics of a high speed PWC is presented and a strong...

  16. Evaluation of a new device for sterilizing dental high-speed handpieces

    DEFF Research Database (Denmark)

    Larsen, T; Andersen, H K; Fiehn, N E

    1997-01-01

    Dental high-speed turbines and handpieces can take up and expel microorganisms during operation and thus need regular sterilization. This study established a method for validating devices used to sterilize high-speed turbines and handpieces. The air and water channels and turbine chambers were...

  17. Dynamics of High-Speed Rotors Supported in Sliding Bearings

    Science.gov (United States)

    Šimek, J.; Svoboda, R.

    The higher the operating speed, the more serious are problems with rotor stability. Three basic groups of rotors are analyzed and some methods of suppressing instability are shown. In the first group are classical elastic rotors supported in hydrodynamic bearings. Practically all high-speed rotors now run in tilting pad bearings, which are inherently stable, but in specific conditions even tiling pad bearings may not ensure rotor stability. The second group is composed of combustion engines turbocharger rotors, which are characteristic by heavy impellers at both overhung ends of elastic shaft. These rotors are in most cases supported in floating ring bearings, which bring special features to rotor behaviour. The third group of rotors with gas bearings exhibits special features.

  18. High Speed and High Accuracy Control of Industrial Articulated Robot Arms with Jerk Restraint by Spline Interpolated Taught Data

    Science.gov (United States)

    Goto, Satoru; Iwanaga, Takuya; Kyura, Nobuhiro; Nakamura, Masatoshi

    In industrial robot arms, high speed and high accurate operation is required. However in case of high speed operation, it often arises high jerk, i, e., rapid change of acceleration. Jerk causes deterioration of control performance such as vibration of a tip of a robot arm. It is, therefore, important to reduce jerk during robot arm operation. In this research, spline interpolation is used to reduce jerk under torque and speed constraints. Effectiveness of the proposed method was assured by experimental results and simulation results of an actual robot arm.

  19. Analysis of coupling between high-speed railway and common speed railway system in transportation corridor

    Science.gov (United States)

    Zhou, Hongchang; Li, Haijun; Chen, Xiaohong; Zhu, Changfeng

    2017-04-01

    The high-speed railway and common speed railway subsystems as important components of the railway transportation system, can make railway traffic organization more orderly, when there are a rational division and balance development between them. In order to quantitatively evaluate the coordinate relations between high-speed railway subsystem and common speed railway subsystem, this paper takes the railway transportation corridor from Baoji to Lanzhou as an example. Firstly, using Logit model and grey forecasting model predict the passenger volume, passenger turnover and time value of high-speed railway and common speed railway in the Baoji-Lanzhou corridor. And then, the coupling forecast model of these two subsystems is established. Lastly, the coupling and coupling coordination of these two subsystems using are predicted and analyzed at theatrically level.

  20. INFLUENCE OF OPERABILITY CRITERIA LIMITING VALUES ON SHIP SPEED

    Directory of Open Access Journals (Sweden)

    Jasna Prpić-Oršić

    2016-09-01

    Full Text Available When the ship is caught in heavy seas, there are two manoeuvres that the shipmaster can undertake to avoid excessive ship motion and hull damage: changing course or voluntary speed reduction. This paper presents a study of the effect of the various voluntary speed reduction criteria to attainable speed of ship on seaway. The speed loss is calculated by taking into account wind and wave effect on ship speed, the engine and propeller performance in actual seas as well as the mass inertia of the ship. The attainable ship speed for ship in head, following and beam waves by accounting for voluntary speed reduction is estimated for various significant wave height. The criteria of slamming, deck wetness, propeller emergence, excessive accelerations and roll are taken into account. The impact of variations of the limiting values of certain criteria due to which the captain intentionally reduces the ship speed is analysed and discussed.

  1. Software Developed for Analyzing High- Speed Rolling-Element Bearings

    Science.gov (United States)

    Fleming, David P.

    2005-01-01

    COBRA-AHS (Computer Optimized Ball & Roller Bearing Analysis--Advanced High Speed, J.V. Poplawski & Associates, Bethlehem, PA) is used for the design and analysis of rolling element bearings operating at high speeds under complex mechanical and thermal loading. The code estimates bearing fatigue life by calculating three-dimensional subsurface stress fields developed within the bearing raceways. It provides a state-of-the-art interactive design environment for bearing engineers within a single easy-to-use design-analysis package. The code analyzes flexible or rigid shaft systems containing up to five bearings acted upon by radial, thrust, and moment loads in 5 degrees of freedom. Bearing types include high-speed ball, cylindrical roller, and tapered roller bearings. COBRA-AHS is the first major upgrade in 30 years of such commercially available bearing software. The upgrade was developed under a Small Business Innovation Research contract from the NASA Glenn Research Center, and incorporates the results of 30 years of NASA and industry bearing research and technology.

  2. High-Speed Interferometry Under Impacting Drops

    KAUST Repository

    Langley, Kenneth R.

    2017-08-31

    Over the last decade the rapid advances in high-speed video technology, have opened up to study many multi-phase fluid phenomena, which tend to occur most rapidly on the smallest length-scales. One of these is the entrapment of a small bubble under a drop impacting onto a solid surface. Here we have gone from simply observing the presence of the bubble to detailed imaging of the formation of a lubricating air-disc under the drop center and its subsequent contraction into the bubble. Imaging the full shape-evolution of the air-disc has required μm and sub-μs space and time resolutions. Time-resolved 200 ns interferometry with monochromatic light, has allowed us to follow individual fringes to obtain absolute air-layer thicknesses, based on the eventual contact with the solid. We can follow the evolution of the dimple shape as well as the compression of the gas. The improved imaging has also revealed new levels of detail, like the nature of the first contact which produces a ring of micro-bubbles, highlighting the influence of nanometric surface roughness. Finally, for impacts of ultra-viscous drops we see gliding on ~100 nm thick rarified gas layers, followed by extreme wetting at numerous random spots.

  3. HORNET: High-speed Onion Routing at the Network Layer

    OpenAIRE

    Chen, Chen; Asoni, Daniele Enrico; Barrera, David; Danezis, George; Perrig, Adrian

    2015-01-01

    We present HORNET, a system that enables high-speed end-to-end anonymous channels by leveraging next generation network architectures. HORNET is designed as a low-latency onion routing system that operates at the network layer thus enabling a wide range of applications. Our system uses only symmetric cryptography for data forwarding yet requires no per-flow state on intermediate nodes. This design enables HORNET nodes to process anonymous traffic at over 93 Gb/s. HORNET can also scale as requ...

  4. Variable speed induction motor operation from a 20-kHz power bus

    Science.gov (United States)

    Hansen, Irving G.

    Induction motors are recognized for their simple rugged construction to date, however, their application to variable speed or servo drives has been hampered by limitations on their control. Induction motor drives tend to be complex and to display troublesome low speed characteristics due in part to nonsinusoidal driving voltages. A technique was developed which involves direct synthesis of sinusoidal driving voltages from a high frequency power bus and independent control of frequency and voltages. Separation offrequency and voltage allows independent control of rotor and stator flux, full four-quadrant operation, and instantaneous torque control. Recent test results, current status of the technology, and proposed aerospace applications will be discussed.

  5. High Speed Link Radiated Emission Reduction

    Science.gov (United States)

    Bisognin, P.; Pelissou, P.; Cissou, R.; Giniaux, M.; Vargas, O.

    2016-05-01

    To control the radiated emission of high-speed link and associated unit, the current approach is to implement overall harness shielding on cables bundles. This method is very efficient in the HF/ VHF (high frequency/ very high frequency) and UHF (ultra-high frequency) ranges when the overall harness shielding is properly bonded on EMC back-shell. Unfortunately, with the increasing frequency, the associated half wavelength matches with the size of Sub-D connector that is the case for the L band. Therefore, the unit connectors become the main source of interference emission. For the L-band and S-band, the current technology of EMC back-shell leaves thin aperture matched with the L band half wavelength and therefore, the shielding effectiveness is drastically reduced. In addition, overall harness shielding means significant increases of the harness mass.Airbus D&S Toulouse and Elancourt investigated a new solution to avoid the need of overall harness shielding. The objective is to procure EM (Electro-Magnetic) clean unit connected to cables bundles free of any overall harness shielding. The proposed solution is to implement EMC common mode filtering on signal interfaces directly on unit PCB as close as possible the unit connector.Airbus D&S Elancourt designed and manufactured eight mock-ups of LVDS (Low Voltage Differential Signaling) interface PCBs' with different solutions of filtering. After verification of the signal integrity, three mock-ups were retained (RC filter and two common mode choke coil) in addition to the reference one (without EMC filter).Airbus D&S Toulouse manufactured associated LVDS cable bundles and integrated the RX (Receiver) and TX (Transmitter) LVDS boards in shielded boxes.Then Airbus D&S performed radiated emission measurement of the LVDS links subassemblies (e.g. RX and TX boxes linked by LVDS cables) according to the standard test method. This paper presents the different tested solutions and main conclusions on the feasibility of such

  6. An assessment of high-speed rail safety issues and research needs

    Science.gov (United States)

    1990-12-01

    The objectives of the study were to provide the Federal Railroad Administration Office of Research and Development with the following information: A general description and operating characteristics of high-speed rail systems likely to be installed i...

  7. The Use of Shock Isolation mounts in Small High-Speed Craft to Protect Equipment from Wave Slam Effects

    Science.gov (United States)

    2017-07-01

    including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services , Directorate for Information Operations and... failure during high-speed operations in rough seas is discussed. 15. SUBJECT TERMS Shock mounts planing craft equipment data...shock isolation systems. An alternative method for minimizing the risk of equipment failure during high-speed operations in rough seas is discussed

  8. High speed flow cytometric separation of viable cells

    Science.gov (United States)

    Sasaki, Dennis T.; Van den Engh, Gerrit J.; Buckie, Anne-Marie

    1995-01-01

    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  9. Experimental Performance Study of a High Speed Oil Lubricated Polymer Thrust Bearing

    Directory of Open Access Journals (Sweden)

    Jie Zhou

    2015-01-01

    Full Text Available With the demand for turbomachinery to operate at higher speeds, loads, and power, fluid film bearings that support turbomachinery must be capable of operating in these more demanding applications. Thrust bearings operating at high speeds and loads can experience high surface temperatures and thin fluid film thickness. Typically, babbitt (white metal is the bearing lining material for most turbomachinery bearings but is limited in operating temperature and allowable film thickness. Polymer based materials are alternative materials that can operate at high temperatures and with thin films and have been in use for many decades in high load applications, such as electric submersible pumps (ESP. Test results of polymer lined thrust bearings subjected to modern turbomachinery speeds and loads are presented and compared to babbitt lined bearings of the same design and under similar conditions. The test results show polymer lined thrust bearings can operate at higher bearing unit loads than babbitt.

  10. Water Containment Systems for Testing High-Speed Flywheels

    Science.gov (United States)

    Trase, Larry; Thompson, Dennis

    2006-01-01

    Water-filled containers are used as building blocks in a new generation of containment systems for testing high-speed flywheels. Such containment systems are needed to ensure safety by trapping high-speed debris in the event of centrifugal breakup or bearing failure. Traditional containment systems for testing flywheels consist mainly of thick steel rings. The effectiveness of this approach to shielding against high-speed debris was demonstrated in a series of tests.

  11. Chicago-St. Louis high speed rail plan

    Energy Technology Data Exchange (ETDEWEB)

    Stead, M.E.

    1994-12-31

    The Illinois Department of Transportation (IDOT), in cooperation with Amtrak, undertook the Chicago-St. Louis High Speed Rail Financial and Implementation Plan study in order to develop a realistic and achievable blueprint for implementation of high speed rail in the Chicago-St. Louis corridor. This report presents a summary of the Price Waterhouse Project Team`s analysis and the Financial and Implementation Plan for implementing high speed rail service in the Chicago-St. Louis corridor.

  12. High-speed Stochastic Fatigue Testing

    DEFF Research Database (Denmark)

    Brincker, Rune; Sørensen, John Dalsgaard

    1990-01-01

    testing, quite unacceptable errors are introduced. Usually this problem is solved by running the tests at very low speeds and by editing the load history in order to reduce the duration of the test. In this paper a new method for control of stochastic fatigue tests is proposed. It is based on letting...

  13. Aerodynamic effects of high-speed passenger trains on other trains.

    Science.gov (United States)

    2002-04-01

    This study assesses the potential safety risks associated with aerodynamic loads produced by the Acela high-speed train when passing freight and bi-level commuter passenger cars. Acela operates at speeds up to 150 mph, on tangent tracks adjacent to n...

  14. Effect of Cutting Fluids on the Flank Wear of High Speed and ...

    African Journals Online (AJOL)

    The effect of some cutting fluids namely: Mentholated spirit, paraffin, and soluble oil on the flank wear of High-speed steel and carbide tipped tools by orthogonal cutting has been studied. Cente lathe was used for cylindrical turning operated at a speed of 370rpm and depth of cut of 1mm to machine aluminum, brass, mild ...

  15. Environmental impact statement : Chicago-St. Louis high speed rail project

    Science.gov (United States)

    2000-05-16

    The proposed action would provide High-Speed Rail (HSR) passenger service between Chicago and St. Louis, operating at top speeds of 110 mph (180 kph) through most of the project area, except for a 29-kilometer (18-mile) segment between Lincoln and Sp...

  16. High-speed rail aerodynamic assessment and mitigation report : final report.

    Science.gov (United States)

    2015-12-01

    This report advances the current state of knowledge, as well as shared understanding and evaluation of present procedures used to : mitigate the impacts effects from high-speed trains (HST) operating at speeds between 110 mph and 250 mph. This work g...

  17. High-speed rail-coming to America?

    Science.gov (United States)

    Cameron, David Ossian

    2009-01-01

    The United States lags many parts of the world when it comes to high-speed rail. But investing in high-speed rail could help us through current problems. Funds- $8 billion-in the economic stimulus package passed by Congress are designated for high-speed rail. Other funds in the pipeline total approximately $15.5 billion. High-speed rail can relieve congestion, free up national airspace, provide reliable transportation and positive economic development, create jobs, and is more energy efficient than other modes of travel.

  18. The high-speed train and its spatial effects

    OpenAIRE

    Javier Gutiérrez Puebla

    2004-01-01

    This paper analyses the high-speed train from a spatial point of view. The basic characteristics of this transportation mode,the evolution of high-speed networks in several countries and the building of a trans-European high-speed railway network are studied.The paper analyses also the process of space-time convergence and its consequences on competitivity and cohesion;the tunel effect;the impact of the high speed-train on transportation demand;and the impacts on the city.

  19. Development of High Speed Inverter Rotary Compressor for the Air-conditioning System

    Science.gov (United States)

    Kang, Seoung-Min; Yang, Eun-soo; Shin, Jin-Ung; Park, Joon-Hong; Lee, Se-Dong; Ha, Jong-Hun; Son, Young-Boo; Lee, Byeong-Chul

    2015-08-01

    In order to meet the various operating loads of an air-conditioning system, an inverter compressor with a wide operational range is necessary. One of the ways to achieve a wide operation range is to drive a small capacity compressor at high speed. Moreover, it is possible to maximize the efficiency in part-load operation condition close to actual operating conditions and to reduce the cost by compact design of a small capacity compressor. In addition, the shortage of maximum capacity, due to the small rated capacity, is covered through high speed operation. However, in general, if the compressor operates at high speed, problems occurs such as reduced efficiency due to friction, increased noise, increased amount of oil discharge and decreased durability of the main components. In order to solve these problems the following have been investigated: optimized dimension parameters of the compression chamber, enhanced shaft design and the structure for the reduction of oil discharge and noise at high speed operation. Finally the high speed inverter rotary compressor with high efficiency and more compact size has been developed as compared with the conventional rotary compressor.

  20. High Speed and Wide Bandwidth Delta-Sigma ADCs

    NARCIS (Netherlands)

    Bolatkale, M.

    2013-01-01

    This thesis describes the theory, design and implementation of a high-speed, high-performance continuous-time delta-sigma (CT??) ADC for applications such as medical imaging, high-definition video processing, and wireline and wireless communications. In order to achieve a GHz clocking speed, this

  1. Time optimal paths for high speed maneuvering

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Lenhart, S.M.

    1993-01-01

    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  2. Design and Analysis of a High Speed Carry Select Adder

    OpenAIRE

    Simarpreet Singh Chawla; Swapnil Aggarwal; Anshika; Nidhi Goel

    2015-01-01

    An optimal high-speed and low-power VLSI architecture requires an efficient arithmetic processing unit that is optimized for speed and power consumption. Adders are one of the widely used in digital integrated circuit and system design. High speed adder is the necessary component in a data path, e.g. Microprocessors and a Digital signal processor. The present paper proposes a novel high-speed adder by combining the advantages of Carry Look Ahead Adder (CLAA) and Carry Select Adder (CSA), devi...

  3. Design and Analysis of a High Speed Carry Select Adder

    OpenAIRE

    Simarpreet Singh Chawla; Swapnil Aggarwal; Anshika; Nidhi Goel

    2015-01-01

    An optimal high-speed and low-power VLSI architecture requires an efficient arithmetic processing unit that is optimized for speed and power consumption. Adders are one of the widely used in digital integrated circuit and system design.High speed adder is the necessary component in a data path, e.g. Microprocessors and a Digital signal processor. The present paper proposes a novel high-speed adder by combining the advantages of Carry Look Ahead Adder (CLAA) and Carry Select Adder (CSA), devis...

  4. HIGH SPEED RAILWAY LINES – FUTURE PART OF CZECH RAILWAY NETWORK?

    Directory of Open Access Journals (Sweden)

    Lukáš Týfa

    2017-08-01

    Full Text Available The paper first describes high speed rail generally and explains the relationship between high speed and conventional railway networks (according to the vehicle types in operation on the network. The core of the paper is comprised of the methodology for choosing the best route for a railway line and its application to the high speed railway connection Praha – Brno. The Algorithm used assumes the existence of more route proposals, which could be different in terms of the operational conception, line routing or types of vehicles used. The optimal variant is the one with the lowest daily cost, which includes infrastructure and vehicle costs; investment and operational costs. The results from applying this model confirmed the assumption, that a dedicated high speed railway line, only for high speed trains, has the same or lower investment costs than a line for both high speed and conventional trains. Furthermore, a dedicated high line also has a lower cost for infrastructure maintenance but a higher cost for buying high speed multiple units.

  5. Reflectively coupled waveguide photodetector for high speed optical interconnection.

    Science.gov (United States)

    Hsu, Shih-Hsiang

    2010-01-01

    To fully utilize GaAs high drift mobility, techniques to monolithically integrate In0.53Ga0.47As p-i-n photodetectors with GaAs based optical waveguides using total internal reflection coupling are reviewed. Metal coplanar waveguides, deposited on top of the polyimide layer for the photodetector's planarization and passivation, were then uniquely connected as a bridge between the photonics and electronics to illustrate the high-speed monitoring function. The photodetectors were efficiently implemented and imposed on the echelle grating circle for wavelength division multiplexing monitoring. In optical filtering performance, the monolithically integrated photodetector channel spacing was 2 nm over the 1,520-1,550 nm wavelength range and the pass band was 1 nm at the -1 dB level. For high-speed applications the full-width half-maximum of the temporal response and 3-dB bandwidth for the reflectively coupled waveguide photodetectors were demonstrated to be 30 ps and 11 GHz, respectively. The bit error rate performance of this integrated photodetector at 10 Gbit/s with 2(7)-1 long pseudo-random bit sequence non-return to zero input data also showed error-free operation.

  6. High Speed Water Sterilization Using One-Dimensional Nanostructures

    KAUST Repository

    Schoen, David T.

    2010-09-08

    The removal of bacteria and other organisms from water is an extremely important process, not only for drinking and sanitation but also industrially as biofouling is a commonplace and serious problem. We here present a textile based multiscale device for the high speed electrical sterilization of water using silver nanowires, carbon nanotubes, and cotton. This approach, which combines several materials spanning three very different length scales with simple dying based fabrication, makes a gravity fed device operating at 100000 L/(h m2) which can inactivate >98% of bacteria with only several seconds of total incubation time. This excellent performance is enabled by the use of an electrical mechanism rather than size exclusion, while the very high surface area of the device coupled with large electric field concentrations near the silver nanowire tips allows for effective bacterial inactivation. © 2010 American Chemical Society.

  7. Florida High Speed Rail Authority - 2003 report to the legislature

    Science.gov (United States)

    2003-01-01

    Since its last full report to the Legislature in January 2002, the Florida High Speed Rail Authority (FHSRA) has continued to fulfill the duties defined in the Florida High Speed Rail Authority Act, Section 341.8201 to 341.842, Florida Statutes. The ...

  8. Advancing high-speed rail policy in the United States.

    Science.gov (United States)

    2012-06-01

    This report builds on a review of international experience with high-speed rail projects to develop recommendations for a High-speed rail policy framework for the United States. The international review looked at the experience of Korea, Taiwan, Chin...

  9. Optical Systems for Ultra-High-Speed TDM Networking

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Mulvad, Hans Christian Hansen

    2014-01-01

    This paper discusses key results in the field of high speed optical networking with particular focus on packet-based systems. Schemes for optical packet labeling, packet switching and packet synchronization will be discussed, along with schemes for optical clock recovery, channel identification...... and detection of ultra-high-speed optical signals....

  10. Optical Systems for Ultra-High-Speed TDM Networking

    Directory of Open Access Journals (Sweden)

    Michael Galili

    2014-04-01

    Full Text Available This paper discusses key results in the field of high speed optical networking with particular focus on packet-based systems. Schemes for optical packet labeling, packet switching and packet synchronization will be discussed, along with schemes for optical clock recovery, channel identification and detection of ultra-high-speed optical signals.

  11. Rounding Technique for High-Speed Digital Signal Processing

    Science.gov (United States)

    Wechsler, E. R.

    1983-01-01

    Arithmetic technique facilitates high-speed rounding of 2's complement binary data. Conventional rounding of 2's complement numbers presents problems in high-speed digital circuits. Proposed technique consists of truncating K + 1 bits then attaching bit in least significant position. Mean output error is zero, eliminating introducing voltage offset at input.

  12. CMOS Image Sensors for High Speed Applications

    OpenAIRE

    Jamal Deen, M.; Qiyin Fang; Louis Liu; Frances Tse; David Armstrong; Munir El-Desouki

    2009-01-01

    Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm) due to ...

  13. DEVELOPMENT OF THE COMPLEX-ALLOYED STEEL OF INCREASED HARDENABILITY, VISCOSITY AND HEAT-RESISTANCE FOR CUTTING PARTS OF HIGH-SPEED INSTRUMENT, OPERATING IN CONDITIONS OF HEATING UP AND DYNAMIC LOADS

    Directory of Open Access Journals (Sweden)

    V. N. Fedulov

    2006-01-01

    Full Text Available The theoretical aspects of development of the complex-alloyed steel compounds for cutting parts of high-speed instrument, particularly influence of alloying elements on its structure and characteristics are considered. It is shown that combined alloying of steel by carbon, chrome, silicon, manganese, vanadium and molybdenum in a certain proportion allows to reach the intended aim, achieving at the same time increase of solidity, impact elasticity and heat stability.

  14. An examination of loads and responses of a wind turbine undergoing variable-speed operation

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A.D.; Buhl, M.L. Jr.; Bir, G.S.

    1996-11-01

    The National Renewable Energy Laboratory has recently developed the ability to predict turbine loads and responses for machines undergoing variable-speed operation. The wind industry has debated the potential benefits of operating wind turbine sat variable speeds for some time. Turbine system dynamic responses (structural response, resonance, and component interactions) are an important consideration for variable-speed operation of wind turbines. The authors have implemented simple, variable-speed control algorithms for both the FAST and ADAMS dynamics codes. The control algorithm is a simple one, allowing the turbine to track the optimum power coefficient (C{sub p}). The objective of this paper is to show turbine loads and responses for a particular two-bladed, teetering-hub, downwind turbine undergoing variable-speed operation. The authors examined the response of the machine to various turbulent wind inflow conditions. In addition, they compare the structural responses under fixed-speed and variable-speed operation. For this paper, they restrict their comparisons to those wind-speed ranges for which limiting power by some additional control strategy (blade pitch or aileron control, for example) is not necessary. The objective here is to develop a basic understanding of the differences in loads and responses between the fixed-speed and variable-speed operation of this wind turbine configuration.

  15. Analysis of Contact Stresses in High Speed Sheet Metal Forming Processes

    OpenAIRE

    Bonnen, J.; Gillard, A.; Golovashchenko, S.; Ibrahim, R.; Mamutov, A.; SMITH, L.

    2012-01-01

    In high speed metal forming, determination of contact stresses applied to forming dies is necessary in order to identify the requirements to the die material. Contact stresses greatly control the die design due to their effects on die durability. Very high contact stresses and fracture under impulsive loading have been reported in literature on contact type of high speed forming. In pulsed forming operations using electro-hydraulic forming (EHF), a work piece is often accelerat...

  16. High-speed OCT light sources and systems [Invited

    OpenAIRE

    Klein, Thomas; Huber, Robert

    2017-01-01

    Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems.

  17. High-speed OCT light sources and systems [Invited].

    Science.gov (United States)

    Klein, Thomas; Huber, Robert

    2017-02-01

    Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems.

  18. High-speed OCT light sources and systems [Invited

    Science.gov (United States)

    Klein, Thomas; Huber, Robert

    2017-01-01

    Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems. PMID:28270988

  19. Investigation of a Plasma Ball using a High Speed Camera

    Science.gov (United States)

    Laird, James; Zweben, Stewart; Raitses, Yevgeny; Zwicker, Andrew; Kaganovich, Igor

    2008-11-01

    The physics of how a plasma ball works is not clearly understood. A plasma ball is a commercial ``toy'' in which a center electrode is charged to a high voltage and lightning-like discharges fill the ball with many plasma filaments. The ball uses high voltage applied on the center electrode (˜5 kV) which is covered with glass and capacitively coupled to the plasma filaments. This voltage oscillates at a frequency of ˜26 kHz. A Nebula plasma ball from Edmund Scientific was filmed with a Phantom v7.3 camera, which can operate at speeds up to 150,000 frames per second (fps) with a limit of >=2 μsec exposure per frame. At 100,000 fps the filaments were only visible for ˜5 μsec every ˜40 μsec. When the plasma ball is first switched on, the filaments formed only after ˜800 μsec and initially had a much larger diameter with more chaotic behavior than when the ball reached its final plasma filament state at ˜30 msec. Measurements are also being made of the final filament diameter, the speed of the filament propagation, and the effect of thermal gradients on the filament density. An attempt will be made to explain these results from plasma theory and movies of these filaments will be shown. Possible theoretical models include streamer-like formation, thermal condensation instability, and dielectric barrier discharge instability.

  20. Active resonant subwavelength grating devices for high speed spectroscopic sensing

    Science.gov (United States)

    Gin, A. V.; Kemme, S. A.; Boye, R. R.; Peters, D. W.; Ihlefeld, J. F.; Briggs, R. D.; Wendt, J. R.; Marshall, L. H.; Carter, T. R.; Samora, S.

    2009-02-01

    In this paper, we describe progress towards a multi-color spectrometer and radiometer based upon an active resonant subwavelength grating (RSG). This active RSG component acts as a tunable high-speed optical filter that allows device miniaturization and ruggedization not realizable using current sensors with conventional bulk optics. Furthermore, the geometrical characteristics of the device allow for inherently high speed operation. Because of the small critical dimensions of the RSG devices, the fabrication of these sensors can prove challenging. However, we utilize the state-of-the-art capabilities at Sandia National Laboratories to realize these subwavelength grating devices. This work also leverages previous work on passive RSG devices with greater than 98% efficiency and ~1nm FWHM. Rigorous coupled wave analysis has been utilized to design RSG devices with PLZT, PMN-PT and BaTiO3 electrooptic thin films on sapphire substrates. The simulated interdigitated electrode configuration achieves field strengths around 3×107 V/m. This translates to an increase in the refractive index of 0.05 with a 40V bias potential resulting in a 90% contrast of the modulated optical signal. We have fabricated several active RSG devices on selected electro-optic materials and we discuss the latest experimental results on these devices with variable electrostatic bias and a tunable wavelength source around 1.5μm. Finally, we present the proposed data acquisition hardware and system integration plans.

  1. High-speed digital fiber optic links for satellite traffic

    Science.gov (United States)

    Daryoush, A. S.; Ackerman, E.; Saedi, R.; Kunath, R. R.; Shalkhauser, K.

    1989-01-01

    Large aperture phased array antennas operating at millimeter wave frequencies are designed for space-based communications and imaging platforms. Array elements are comprised of active T/R modules which are linked to the central processing unit through high-speed fiber-optic networks. The system architecture satisfying system requirements at millimeter wave frequency is T/R level data mixing where data and frequency reference signals are distributed independently before mixing at the T/R modules. This paper demonstrates design procedures of a low loss high-speed fiber-optic link used for transmission of data signals over 600-900 MHz bandwidth inside satellite. The fiber-optic link is characterized for transmission of analog and digital data. A dynamic range of 79 dB/MHz was measured for analog data over the bandwidth. On the other hand, for bursted SMSK satellite traffic at 220 Mbps rates, BER of 2 x 10 to the -7th was measured for E(b)/N(o) of 14.3 dB.

  2. Recent high-speed rail vehicles; Kosoku tetsudo sharyo

    Energy Technology Data Exchange (ETDEWEB)

    Sone, S. [The University of Tokyo, Tokyo (Japan); Ishizu, K. [Central Japan Railway Company, Nagoya (Japan); Yoshie, N. [Nishi-Nippon Railroad Co. Ltd., Fukuoka (Japan); Hata, T. [East Japan Railway Co., Tokyo (Japan); Watanabe, T.; Hata, H. [Railway Technical Research Institute, Tokyo (Japan); Brun, D.

    1997-05-01

    This paper describes the latest progress in high speed rail vehicles. It was in 1981 when TGV has inaugurated commercial operation with a speed of 260 km/h. Japan is trying to recover from a setback by putting forward the 300-line vehicle of discrete motive force system, and the 500-line vehicle of complete discrete motive force system featured by reduced weight and a unique power collection system. Central Japan Railway is moving forward a 700-line train aimed at improving comfortability and reducing noise. The 500-line vehicle has vehicular features such as the sharpened head shape, weight reduction and adoption of vibration control, and also such features in electric circuits as centralized main circuit devices and improved monitoring devices. The vehicle`s running test verified stable run at 300 km/h. The Shinkansen vehicle designed by East Japan Railway adopted collective control on the main circuit system, and transferred to a system in which large capacity GTOs are used to drive three-phase induction motors. The Inter City Express has been put into practical use in Germany, with traction vehicles arranged on both ends of a train. Technological characteristics in TGV may be pointed out as avoidance of curves and high gradient. Exchange of electric train technologies is in progress between Japan and Europe. 19 refs., 27 figs., 6 tabs.

  3. Advanced Ultra-High Speed Motor for Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Impact Technologies LLC; University of Texas at Arlington

    2007-03-31

    Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at

  4. Parametric Optimization for High Speed FLIM Implementation

    Directory of Open Access Journals (Sweden)

    Kim Jayul

    2015-01-01

    Full Text Available FLIM (Fluorescence Lifetime Imaging Microscopy has been considered an effective technique to investigate chemical properties of the specimens, especially of biological samples. Despite of this advantageous trait, researchers in this field have had difficulties applying FLIM to their systems because acquiring an image using FLIM consumes too much time. To increase the FLIM speed, many methodologies have been developed and applied to the system. One of the recent methodologies is an analogue mean delay based FLIM using a PMT and digitizer for image reconstruction. In this system, however, imaging time is largely dependent upon several parameters such as data transfer rate, sampling rate of an A/D converter, and signal width etc. In this paper, such parametric optimization method is introduced for faster acquisition of the image.

  5. The use of high-speed imaging in education

    Science.gov (United States)

    Kleine, H.; McNamara, G.; Rayner, J.

    2017-02-01

    Recent improvements in camera technology and the associated improved access to high-speed camera equipment have made it possible to use high-speed imaging not only in a research environment but also specifically for educational purposes. This includes high-speed sequences that are created both with and for a target audience of students in high schools and universities. The primary goal is to engage students in scientific exploration by providing them with a tool that allows them to see and measure otherwise inaccessible phenomena. High-speed imaging has the potential to stimulate students' curiosity as the results are often surprising or may contradict initial assumptions. "Live" demonstrations in class or student- run experiments are highly suitable to have a profound influence on student learning. Another aspect is the production of high-speed images for demonstration purposes. While some of the approaches known from the application of high speed imaging in a research environment can simply be transferred, additional techniques must often be developed to make the results more easily accessible for the targeted audience. This paper describes a range of student-centered activities that can be undertaken which demonstrate how student engagement and learning can be enhanced through the use of high speed imaging using readily available technologies.

  6. Modern trends in designing high-speed trains

    Directory of Open Access Journals (Sweden)

    Golubović Snežana D.

    2015-01-01

    Full Text Available Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains. Not only do these types of trains comply with the need for increased speed of transportation and make the duration of the journey shorter, but they also meet the demands for increased reliability, safety and direct application of energy efficiency to the transportation system itself. Along with increased train speed, the motion resistance is increased as well, whereby at speeds over 200 km/h the proportion of air resistance becomes the most dominant member. One of the most efficient measures for reducing air resistance, as well as other negative consequences of high-speed motion, is the development of the aerodynamic shape of the train. This paper presents some construction solutions that affect the aerodynamic properties of high-speed trains, first and foremost, the nose shape, as well as the similarities and differences of individual subsystems necessary for the functioning of modern high-speed rail systems. We analysed two approaches to solving the problem of the aerodynamic shape of the train and the appropriate infrastructure using the examples of Japan and France. Two models of high-speed trains, Shinkansen (Japan and TGV, i.e. AGV (France, have been discussed.

  7. Yonjung High-Speed Railway Bridge Assessment Using Output-Only Structural Health Monitoring Measurements under Train Speed Changing

    Directory of Open Access Journals (Sweden)

    Mosbeh R. Kaloop

    2016-01-01

    Full Text Available Yonjung Bridge is a hybrid multispan bridge that is designed to transport high-speed trains (HEMU-430X with maximum operating speed of 430 km/h. The bridge consists of simply supported prestressed concrete (PSC and composite steel girders to carry double railway tracks. The structural health monitoring system (SHM is designed and installed to investigate and assess the performance of the bridge in terms of acceleration and deformation measurements under different speeds of the passing train. The SHM measurements are investigated in both time and frequency domains; in addition, several identification models are examined to assess the performance of the bridge. The drawn conclusions show that the maximum deflection and acceleration of the bridge are within the design limits that are specified by the Korean and European codes. The parameters evaluation of the model identification depicts the quasistatic and dynamic deformations of PSC and steel girders to be different and less correlated when higher speeds of the passing trains are considered. Finally, the variation of the frequency content of the dynamic deformations of the girders is negligible when high speeds are considered.

  8. Closed-loop controlled pantograph for high-speed applications; Geregelter Stromabnehmer fuer Hochgeschwindigkeitsanwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Baldauf, W.; Kolbe, M. [Deutsche Bahn AG, Muenchen (Germany). Technik/Beschaffung, DB Systemtechnik T.TZF72; Kroetz, W. [Deutsche Bahn AG, Frankfurt am Main (Germany). Technik/Beschaffung, DB Systemtechnik T.TZF72

    2005-04-15

    Passive high-speed pantographs have achieved an excellent level of performance; however, they reach their limits when increasing the operational speed at existing contact line installations. The new actively controlled single-arm pantograph, which has been developed by German Railway (DB) and industry, allows raising the operational speeds on DB's existing network reducing at the same time the wear and the noise emission. Simulations, tests of prototypes in a wind tunnel and in test stands and in-service trials confirmed the expectations. (orig.)

  9. On-line high-speed rail defect detection.

    Science.gov (United States)

    2004-10-01

    This report presents the results of phase 2 of the project On-line high-speed rail defect detection aimed at improving the reliability and the speed of current defect detection in rails. Ultrasonic guided waves, traveling in the rail running di...

  10. WIND TURBINE OPERATION PARAMETER CHARACTERISTICS AT A GIVEN WIND SPEED

    Directory of Open Access Journals (Sweden)

    Zdzisław Kamiński

    2014-06-01

    Full Text Available This paper discusses the results of the CFD simulation of the flow around Vertical Axis Wind Turbine rotor. The examined rotor was designed following patent application no. 402214. The turbine operation is characterised by parameters, such as opening angle of blades, power, torque, rotational velocity at a given wind velocity. Those parameters have an impact on the performance of entire assembly. The distribution of forces acting on the working surfaces in the turbine can change, depending on the angle of rotor rotation. Moreover, the resultant force derived from the force acting on the oncoming and leaving blades should be as high as possible. Accordingly, those parameters were individually simulated over time for each blade in three complete rotations. The attempts to improve the performance of the entire system resulted in a new research trend to improve the performance of working turbine rotor blades.

  11. High Speed Railway Environment Safety Evaluation Based on Measurement Attribute Recognition Model

    Directory of Open Access Journals (Sweden)

    Qizhou Hu

    2014-01-01

    Full Text Available In order to rationally evaluate the high speed railway operation safety level, the environmental safety evaluation index system of high speed railway should be well established by means of analyzing the impact mechanism of severe weather such as raining, thundering, lightning, earthquake, winding, and snowing. In addition to that, the attribute recognition will be identified to determine the similarity between samples and their corresponding attribute classes on the multidimensional space, which is on the basis of the Mahalanobis distance measurement function in terms of Mahalanobis distance with the characteristics of noncorrelation and nondimensionless influence. On top of the assumption, the high speed railway of China environment safety situation will be well elaborated by the suggested methods. The results from the detailed analysis show that the evaluation is basically matched up with the actual situation and could lay a scientific foundation for the high speed railway operation safety.

  12. Radio Wave Propagation Scene Partitioning for High-Speed Rails

    Directory of Open Access Journals (Sweden)

    Bo Ai

    2012-01-01

    Full Text Available Radio wave propagation scene partitioning is necessary for wireless channel modeling. As far as we know, there are no standards of scene partitioning for high-speed rail (HSR scenarios, and therefore we propose the radio wave propagation scene partitioning scheme for HSR scenarios in this paper. Based on our measurements along the Wuhan-Guangzhou HSR, Zhengzhou-Xian passenger-dedicated line, Shijiazhuang-Taiyuan passenger-dedicated line, and Beijing-Tianjin intercity line in China, whose operation speeds are above 300 km/h, and based on the investigations on Beijing South Railway Station, Zhengzhou Railway Station, Wuhan Railway Station, Changsha Railway Station, Xian North Railway Station, Shijiazhuang North Railway Station, Taiyuan Railway Station, and Tianjin Railway Station, we obtain an overview of HSR propagation channels and record many valuable measurement data for HSR scenarios. On the basis of these measurements and investigations, we partitioned the HSR scene into twelve scenarios. Further work on theoretical analysis based on radio wave propagation mechanisms, such as reflection and diffraction, may lead us to develop the standard of radio wave propagation scene partitioning for HSR. Our work can also be used as a basis for the wireless channel modeling and the selection of some key techniques for HSR systems.

  13. High speed high dynamic range high accuracy measurement system

    Science.gov (United States)

    Deibele, Craig E.; Curry, Douglas E.; Dickson, Richard W.; Xie, Zaipeng

    2016-11-29

    A measuring system includes an input that emulates a bandpass filter with no signal reflections. A directional coupler connected to the input passes the filtered input to electrically isolated measuring circuits. Each of the measuring circuits includes an amplifier that amplifies the signal through logarithmic functions. The output of the measuring system is an accurate high dynamic range measurement.

  14. High-speed optical measurement for the drumhead vibration

    Science.gov (United States)

    Zhang, Qican; Su, Xianyu

    2005-04-01

    In this paper, a high-speed optical measurement for the vibrating drumhead is presented and verified by experiment. A projected sinusoidal fringe pattern on the measured drumhead is dynamically deformed with the vibration of the membrane and grabbed by a high-speed camera. The shape deformation of the drumhead at each sampling instant can be recovered from this sequence of obtained fringe patterns. The vibration of the membrane of a Chinese drum has been measured with a high speed sampling rate (1,000 fps) and a standard deviation (0.075 mm). The restored vibration of the drumhead is also presented in an animation.

  15. New high-speed line Nuremberg - Ingolstadt - Electrical engineering equipment; Neubaustrecke (NBS) Nuernberg - Ingolstadt - Technische Ausruestung

    Energy Technology Data Exchange (ETDEWEB)

    Krems, S. [Balfour Beatty Rail GmbH, Berlin (Germany); Matthes, U. [DB Projektbau GmbH, Nuernberg (Germany)

    2007-07-01

    The Bavarian fast railway line Nuremberg - Ingolstadt is equipped with most recent railway infrastructure for a 300 km/h fast high-speed traffic. The electrical engineering installations were implemented within a seven years period. Since December 2006 the line has been integrated into scheduled services and operated with high-speed trains. So far, the installations complied fully with all the requirements. (orig.)

  16. Material Derivative Measurements in High-Speed Flows by Four-Pulse Tomographic PIV

    NARCIS (Netherlands)

    Lynch, K.; Scarano, F.

    2013-01-01

    A tomographic PIV system is introduced for the instantaneous measurement of the material derivative of velocity (VMD). The system is able to operate with very short temporal separation and is therefore suitable for applications in high-speed flows. The method of operation consists of the imaging of

  17. Wayside noise and vibration signatures of high-speed trains in the Northeast Corridor

    Science.gov (United States)

    1973-09-01

    Measurements were made of the wayside noise and ground vibration levels generated during the passby of high-speed Metroliner and Trubo-trains operating on the tracks of the Penn Central Railroad. The Metroliner in operation on the Nnew York-to-Washin...

  18. Development and Performance of the ACTS High Speed VSAT

    Science.gov (United States)

    Quintana, J.; Tran, Q.; Dendy, R.

    1999-01-01

    The Advanced Communication Technology Satellite (ACTS), developed by the U.S. National Aeronautics and Space Administration (NASA) has demonstrated the breakthrough technologies of Ka-band, spot beam antennas, and on-board processing. These technologies have enabled the development of very small aperture terminals (VSAT) and ultra-small aperture terminals (USAT) which have capabilities greater than were previously possible with conventional satellite technologies. However, the ACTS baseband processor (BBP) is designed using a time division multiple access (TDMA) scheme, which requires each earth station using the BBP to transmit data at a burst rate which is much higher than the user throughput data rate. This tends to mitigate the advantage of the new technologies by requiring a larger earth station antenna and/or a higher-powered uplink amplifier than would be necessary for a continuous transmission at the user data rate. Conversely, the user data rate is much less than the rate that can be supported by the antenna size and amplifier. For example, the ACTS TI VSAT operates at a burst rate of 27.5 Mbps, but the maximum user data rate is 1.792 Mbps. The throughput efficiency is slightly more than 6.5%. For an operational network, this level of overhead will greatly increase the cost of the user earth stations, and that increased cost must be repeated thousands of times, which may ultimately reduce the market for such a system. The ACTS High Speed VSAT (HS VSAT) is an effort to experimentally demonstrate the maximum user throughput data rate which can be achieved using the technologies developed and implemented on ACTS. Specifically, this was done by operating the system uplinks as frequency division multiple access (FDMA), essentially assigning all available TDMA time slots to a single user on each of two uplink frequencies. Preliminary results show that using a 1.2-m antenna in this mode, the HS VSAT can achieve between 22 and 24 Mbps out of the 27.5 Mbps burst

  19. Method for upgrading the performance at track transitions for high-speed service : next generation high-speed rail program

    Science.gov (United States)

    2001-09-01

    High-speed trains in the speed range of 100 to 160 mph require tracks of nearly perfect geometry and mechanical uniformity, when subjected to moving wheel loads. Therefore, this report briefly describes the remedies being used by various railroads to...

  20. Gait speed predicts post-operative medical complications in elderly gastric cancer patients undergoing gastrectomy.

    Science.gov (United States)

    Chandoo, Arvine; Chi, Chu-Huai; Ji, Weiping; Huang, Yingpeng; Chen, Xiao-Dong; Zhang, Wei-Teng; Wu, Rui-Sen; Shen, Xian

    2017-12-11

    Gait speed is a clinical outcome that can measure the physical performance of elderly gastric patients. The purpose of this study was to determine the importance of gait speed in predicting post-operative morbidities in elderly patients undergoing curative gastrectomy. We conducted a prospective study of 357 elderly patients (≥65 years old) undergoing curative gastrectomy. Preoperative gait speed was measured in a 6-m well-lit and unobstructed hallway. Patients were followed up for the post-operative clinical outcomes. Factors contributing to the post-operative morbidities were analysed using univariate and multivariate analyses. Slow gait speed was present in 95 out of 357 patients (26.61%) which was significantly associated with age (P operative medical complications (P = 0.022). In univariate analysis, age (P = 0.015) and slow gait speed (P = 0.029) were risk factors of post-operative complications. In multivariate analysis, we found that age (P operative medical complications. Slow gait speed is an independent predictor of post-operative medical complications in elderly patients undergoing curative gastrectomy. Those patients should be managed with appropriate perioperative nutritional support and physical exercise which can improve gait speed and reduce the risk of post-operative medical complications. © 2017 Royal Australasian College of Surgeons.

  1. High Speed and High Spatial Density Parameter Measurement Using Fiber Optic Sensing Technology

    Science.gov (United States)

    Parker, Allen R. Jr. (Inventor); Chan, Hon Man (Inventor); Richards, William Lance (Inventor); Piazza, Anthony (Inventor); Hamory, Philip J (Inventor)

    2017-01-01

    The present invention is an improved fiber optic sensing system (FOSS) having the ability to provide both high spatial resolution and high frequency strain measurements. The inventive hybrid FOSS fiber combines sensors from high acquisition speed and low spatial resolution Wavelength-Division Multiplexing (WDM) systems and from low acquisition speed and high spatial resolution Optical Frequency Domain Reflection (OFDR) systems. Two unique light sources utilizing different wavelengths are coupled with the hybrid FOSS fiber to generate reflected data from both the WDM sensors and OFDR sensors operating on a single fiber optic cable without incurring interference from one another. The two data sets are then de-multiplexed for analysis, optionally with conventionally-available WDM and OFDR system analyzers.

  2. Effects of High-Speed Power Training on Muscle Performance and Braking Speed in Older Adults

    Directory of Open Access Journals (Sweden)

    Stephen P. Sayers

    2012-01-01

    Full Text Available We examined whether high-speed power training (HSPT improved muscle performance and braking speed using a driving simulator. 72 older adults (22 m, 50 f; age = 70.6 ± 7.3 yrs were randomized to HSPT at 40% one-repetition maximum (1RM (HSPT: n=25; 3 sets of 12–14 repetitions, slow-speed strength training at 80%1RM (SSST: n=25; 3 sets of 8–10 repetitions, or control (CON: n=22; stretching 3 times/week for 12 weeks. Leg press and knee extension peak power, peak power velocity, peak power force/torque, and braking speed were obtained at baseline and 12 weeks. HSPT increased peak power and peak power velocity across a range of external resistances (40–90% 1RM; P<0.05 and improved braking speed (P<0.05. Work was similar between groups, but perceived exertion was lower in HSPT (P<0.05. Thus, the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST.

  3. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1996-01-01

    The purpose of Phase 1 of the study is to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. The systems we consider are high data rate space communication systems. Also...... components. Node synchronization performed within a Viterbi decoder is discussed, and algorithms for frame synchronization are described and analyzed. We present a list of system configurations that we find potentially useful. Further, the high level architecture of units that contain frame synchronization...

  4. Parallelism and pipelining in high-speed digital simulators

    Science.gov (United States)

    Karplus, W. J.

    1983-01-01

    The attainment of high computing speed as measured by the computational throughput is seen as one of the most challenging requirements. It is noted that high speed is cardinal in several distinct classes of applications. These classes are then discussed; they comprise (1) the real-time simulation of dynamic systems , (2) distributed parameter systems, and (3) mixed lumped and distributed systems. From the 1950s on, the quest for high speed in digital simulators concentrated on overcoming the limitations imposed by the so-called von Neumann bottleneck. Two major architectural approaches have made ig possible to circumvent this bottleneck and attain high speeds. These are pipelining and parallelism. Supercomputers, peripheral array processors, and microcomputer networks are then discussed.

  5. Railroad Embankment Stabilization Demonstration for High-Speed Rail Corridors

    Science.gov (United States)

    2003-02-09

    The development of high-speed railroad corridors in the United States is being considered by Congress as a fuel efficient and economical alternative to air or highway passenger travel. The exisiting infrastructure is, in many ways, suitable for freig...

  6. Promoting intermodal connectivity at California's high-speed rail stations.

    Science.gov (United States)

    2015-07-01

    High-speed rail (HSR) has emerged as one of the most revolutionary and transformative transportation technologies, having a : profound impact on urban-regional accessibility and inter-city travel across Europe, Japan, and more recently China and othe...

  7. Florida High Speed Rail Authority - 2002 report to the legislature

    Science.gov (United States)

    2002-01-01

    This report addresses a legislative requirement that the Authority issue a report of its actions, findings and recommendations. Previous high speed ground transportation studies were reviewed as part of the preparation of this report. Independent ana...

  8. High-speed rail turnout literature review : final report.

    Science.gov (United States)

    2016-08-01

    High-speed rail (HSR) turnout design criteria generally address unbalanced lateral acceleration or cant deficiency (CD), cant deficiency change rate (CDCR), and entry and exit jerk. Various countries have adopted different design values for their HSR...

  9. Safety evaluation of high-speed rail bogie concepts.

    Science.gov (United States)

    2013-10-01

    The study defines the basic design concepts required to provide a safe, reliable, high-speed bogie for the next generation PRIIA passenger locomotive. The requirements and conditions for the U.S. market create unique design challenges that currently ...

  10. High-Speed-/-Hypersonic-Weapon-Development-Tool Integration

    National Research Council Canada - National Science Library

    Duchow, Erin M; Munson, Michael J; Alonge, Jr, Frank A

    2006-01-01

    Multiple tools exist to aid in the design and evaluation of high-speed weapons. This paper documents efforts to integrate several existing tools, including the Integrated Hypersonic Aeromechanics Tool (IHAT)1-7...

  11. High speed railway track dynamics models, algorithms and applications

    CERN Document Server

    Lei, Xiaoyan

    2017-01-01

    This book systematically summarizes the latest research findings on high-speed railway track dynamics, made by the author and his research team over the past decade. It explores cutting-edge issues concerning the basic theory of high-speed railways, covering the dynamic theories, models, algorithms and engineering applications of the high-speed train and track coupling system. Presenting original concepts, systematic theories and advanced algorithms, the book places great emphasis on the precision and completeness of its content. The chapters are interrelated yet largely self-contained, allowing readers to either read through the book as a whole or focus on specific topics. It also combines theories with practice to effectively introduce readers to the latest research findings and developments in high-speed railway track dynamics. It offers a valuable resource for researchers, postgraduates and engineers in the fields of civil engineering, transportation, highway & railway engineering.

  12. High-Speed Thermal Characterization of Cryogenic Flows Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna proposes to continue development on a high-speed fiber optic sensor and readout system for cryogenic temperature measurements in liquid oxygen (LOX) and liquid...

  13. Modern trends in designing high-speed trains

    National Research Council Canada - National Science Library

    Golubović, Snežana D; Rašuo, Boško P; Lučanin, Vojkan J

    2015-01-01

    Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains...

  14. Application of Beyond Bound Decoding for High Speed Optical Communications

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Vegas Olmos, Juan José

    2013-01-01

    This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB....

  15. Characterising argon-bomb balloons for high-speed photography

    CSIR Research Space (South Africa)

    Olivier, M

    2013-08-01

    Full Text Available -1 SABO 2013 TME Workshop Alkantpan Characterising Argon-bomb balloons for High-speed Photography M Olivier and FJ Mostert Landward Sciences, Defence Peace Safety and Security, CSIR, Meiring Naude Road, Pretoria, RSA. Abstract A...

  16. Engineering Data on Selected High Speed Passenger Trucks

    Science.gov (United States)

    1978-07-01

    The purpose of this project is to compile a list of high speed truck engineering parameters for characterization in dynamic performance modeling activities. Data tabulations are supplied for trucks from France, Germany, Italy, England, Japan, U.S.S.R...

  17. Minimum Plate Thickness in High-Speed Craft

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    The minimum plate thickness requirements specified by the classification societies for high-speed craft are supposed to ensure adequate resistance to impact loads such as collision with floating objects and objects falling on the deck. The paper presents analytical methods of describing such impact...... phenomena and proposes performance requirements instead of thickness requirements for hull panels in high-speed craft made of different building materials....

  18. From periphery to core: economic adjustments to high speed rail

    OpenAIRE

    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...

  19. High speed QWIP FPAs on InP substrates

    Science.gov (United States)

    Eker, S. U.; Arslan, Y.; Besikci, C.

    2011-05-01

    Quantum well infrared photodetector (QWIP) technology has allowed the realization of low cost staring focal plane arrays (FPAs). However, AlGaAs/(In)GaAs QWIP FPAs suffer from low quantum and conversion efficiencies under high frame rate and/or low background conditions. We extensively discuss the effect of sensor gain on the FPA performance under various operating conditions, and highlight the superiority of the InP/InGaAs material system with respect to AlGaAs/GaAs for high speed/low background thermal imaging applications. InP/InGaAs QWIPs, providing a bias adjustable gain in a wide range, offer the flexibility of adapting the FPA to strict operating conditions. We also present an experimental comparison of large format AlGaAs/GaAs and (strained) InP/InGaAs QWIP FPAs under different operating conditions. A 640 × 512 QWIP FPA constructed with the 40-well strained InP/In 0.48Ga 0.52As material system displays a cut-off wavelength of 9.7 μm ( λ p = 8.9 μm) with a BLIP temperature higher than 65 K ( f/2), and a peak quantum efficiency as high as 12% with a broad spectral response (Δ λ/ λ p = 17%). The conversion efficiency of the FPA pixels is as high as 20% under large bias (4 V) where the detectivity is reasonably high (˜3 × 10 10 cm Hz 1/2/W, f/2, 65 K). While providing a considerably higher quantum efficiency than the pixels of a similar AlGaAs/GaAs FPA, the InP/InGaAs QWIP provides similar NETD values with much shorter integration times and, being less sensitive to the read noise, successfully operates with sub-millisecond integration times. The results clearly demonstrate that InP based material systems display high potential for single- and dual-band QWIP FPAs by overcoming the limitations of the standard GaAs based QWIPs under high frame rate and/or low background conditions.

  20. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1998-01-01

    The study has been divided into two phases. The purpose of Phase 1 of the study was to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. After selection of which specific...... potentially useful.Algorithms for frame synchronization are described and analyzed. Further, the high level architecture of units that contain frame synchronization and various other functions needed in a complete system is presented. Two such units are described, one for placement before the Viterbi decoder...... towards a realization in an FPGA.Node synchronization performed within a Viterbi decoder is discussed, and the high level architectures of three possible implementations of Viterbi decoders are described: The first implementation uses a number of commercially available decoders while the the two others...

  1. Nanotechnology: high-speed integrated nanowire circuits.

    Science.gov (United States)

    Friedman, Robin S; McAlpine, Michael C; Ricketts, David S; Ham, Donhee; Lieber, Charles M

    2005-04-28

    Macroelectronic circuits made on substrates of glass or plastic could one day make computing devices ubiquitous owing to their light weight, flexibility and low cost. But these substrates deform at high temperatures so, until now, only semiconductors such as organics and amorphous silicon could be used, leading to poor performance. Here we present the use of low-temperature processes to integrate high-performance multi-nanowire transistors into logical inverters and fast ring oscillators on glass substrates. As well as potentially enabling powerful electronics to permeate all aspects of modern life, this advance could find application in devices such as low-cost radio-frequency tags and fully integrated high-refresh-rate displays.

  2. Optimization Based High-Speed Railway Train Rescheduling with Speed Restriction

    Directory of Open Access Journals (Sweden)

    Li Wang

    2014-01-01

    Full Text Available A decision support framework with four components is proposed for high-speed railway timetable rescheduling in case of speed restriction. The first module provides the speed restriction information. The capacity evaluation module is used to evaluate whether the capacity can fulfill the demand before rescheduling timetable based on deduction factor method. The bilayer rescheduling module is the key of the decision support framework. In the bilayer rescheduling module, the upper-layer objective is to make an optimal rerouting plan with selected rerouting actions. Given a specific rerouting plan, the lower-layer focuses on minimizing the total delay as well as the number of seriously impacted trains. The result assessment module is designed to invoke the rescheduling model iteratively with different settings. There are three prominent features of the framework, such as realized interaction with dispatchers, emphasized passengers’ satisfaction, and reduced computation complexity with a bilayer modeling approach. The proposed rescheduling model is simulated on the busiest part of Beijing to Shanghai high-speed railway in China. The case study shows the significance of rerouting strategy and utilization of the railway network capacity in case of speed restriction.

  3. First Deminsys (high speed FBG interrogator) flight

    Science.gov (United States)

    van Els, Thomas J.

    2009-03-01

    Deminsys is the world's fastest multi sensor / multi channel FBG interrogator, identifies one till four channels with typically 8 sensors per channel. The system is especially developed for the interrogation of signals up to 19,3 kHz for each sensor and the sample frequency is independent of the number of sensors. By having multiple sensors per fibre you can create a very compact network of sensors. Due to its revolutionary (light weight, compact and solid state) design, Deminsys seems to fit perfectly into (research) programs for aerospace, medic & life science, maritime, industrial, crash test and all other fast detection applications. Technobis Fibre Technologies (TFT) and NLR made a first test flight with the Deminsys optical fibre measurement system using the NLR test aircraft on October 24th 2008. This flight was a first step in the further development of the current system in order to make it suitable for operation on-board an aircraft and bring it from TRL3 towards TRL5, a functional model for aerospace applications.

  4. High-speed quantum networking by ship.

    Science.gov (United States)

    Devitt, Simon J; Greentree, Andrew D; Stephens, Ashley M; Van Meter, Rodney

    2016-11-02

    Networked entanglement is an essential component for a plethora of quantum computation and communication protocols. Direct transmission of quantum signals over long distances is prevented by fibre attenuation and the no-cloning theorem, motivating the development of quantum repeaters, designed to purify entanglement, extending its range. Quantum repeaters have been demonstrated over short distances, but error-corrected, global repeater networks with high bandwidth require new technology. Here we show that error corrected quantum memories installed in cargo containers and carried by ship can provide a exible connection between local networks, enabling low-latency, high-fidelity quantum communication across global distances at higher bandwidths than previously proposed. With demonstrations of technology with sufficient fidelity to enable topological error-correction, implementation of the quantum memories is within reach, and bandwidth increases with improvements in fabrication. Our approach to quantum networking avoids technological restrictions of repeater deployment, providing an alternate path to a worldwide Quantum Internet.

  5. High-speed scanning: an improved algorithm

    Science.gov (United States)

    Nachimuthu, A.; Hoang, Khoi

    1995-10-01

    In using machine vision for assessing an object's surface quality, many images are required to be processed in order to separate the good areas from the defective ones. Examples can be found in the leather hide grading process; in the inspection of garments/canvas on the production line; in the nesting of irregular shapes into a given surface... . The most common method of subtracting the total area from the sum of defective areas does not give an acceptable indication of how much of the `good' area can be used, particularly if the findings are to be used for the nesting of irregular shapes. This paper presents an image scanning technique which enables the estimation of useable areas within an inspected surface in terms of the user's definition, not the supplier's claims. That is, how much useable area the user can use, not the total good area as the supplier estimated. An important application of the developed technique is in the leather industry where the tanner (the supplier) and the footwear manufacturer (the user) are constantly locked in argument due to disputed quality standards of finished leather hide, which disrupts production schedules and wasted costs in re-grading, re- sorting... . The developed basic algorithm for area scanning of a digital image will be presented. The implementation of an improved scanning algorithm will be discussed in detail. The improved features include Boolean OR operations and many other innovative functions which aim at optimizing the scanning process in terms of computing time and the accurate estimation of useable areas.

  6. High-Speed Edge-Detecting Line Scan Smart Camera

    Science.gov (United States)

    Prokop, Norman F.

    2012-01-01

    A high-speed edge-detecting line scan smart camera was developed. The camera is designed to operate as a component in a NASA Glenn Research Center developed inlet shock detection system. The inlet shock is detected by projecting a laser sheet through the airflow. The shock within the airflow is the densest part and refracts the laser sheet the most in its vicinity, leaving a dark spot or shadowgraph. These spots show up as a dip or negative peak within the pixel intensity profile of an image of the projected laser sheet. The smart camera acquires and processes in real-time the linear image containing the shock shadowgraph and outputting the shock location. Previously a high-speed camera and personal computer would perform the image capture and processing to determine the shock location. This innovation consists of a linear image sensor, analog signal processing circuit, and a digital circuit that provides a numerical digital output of the shock or negative edge location. The smart camera is capable of capturing and processing linear images at over 1,000 frames per second. The edges are identified as numeric pixel values within the linear array of pixels, and the edge location information can be sent out from the circuit in a variety of ways, such as by using a microcontroller and onboard or external digital interface to include serial data such as RS-232/485, USB, Ethernet, or CAN BUS; parallel digital data; or an analog signal. The smart camera system can be integrated into a small package with a relatively small number of parts, reducing size and increasing reliability over the previous imaging system..

  7. High-speed analog-to-digital conversion

    CERN Document Server

    Demler, Michael J

    1991-01-01

    This book covers the theory and applications of high-speed analog-to-digital conversion. An analog-to-digital converter takes real-world inputs (such as visual images, temperature readings, and rates of speed) and transforms them into digital form for processing by computer. This book discusses the design and uses of such circuits, with particular emphasis on improving the speed of the conversion process and the accuracy of its output--how well the output is a corresponding digital representation of the output*b1input signal. As computers become increasingly interfaced to the outside world, ""

  8. The Long-Term Settlement Deformation Automatic Monitoring System for the Chinese High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Xu Wang

    2015-01-01

    Full Text Available The Beijing-Shanghai high-speed railway is one of the milestones of China’s high-speed railway development and its security plays a significant role in China’s economic and social development. However, the evaluation methods used for large-scale security operations and important infrastructure systems, such as the high-speed railways, are discrete and nonlinear; thus they cannot issue emergency warnings in a timely manner. The emergence of optical fiber sensing technology can solve this problem. This technology has progressed rapidly in its application to the monitoring of railway security and it has attracted much attention within the industry. This study considers the newly built passenger railway line between Shijiazhuang and Jinan as an example. The web-based, all-in-one fiber Bragg grating static level is described as well as a set of online monitoring systems, which is automated, real-time, remote, visual, and adaptable to the standards of the Beijing-Shanghai high-speed railway. According to our theoretical analysis, the planned automated monitoring of settlement deformation for the Beijing-Shanghai high-speed railway and the real-time analysis and calculation of monitoring data can ensure the operational security of this section of China’s high-speed railway system.

  9. High Speed Imaging of Diesel Fuel Sprays

    Science.gov (United States)

    Jackson, Ja'kira; Bittle, Joshua

    2016-11-01

    Fuel sprays primarily serve as methods for fuel distribution, fuel/air mixing, and atomization. In this research, a constant pressure flow rig vessel is being tested at various pressures and temperatures using n-heptane. The experiment requires two imaging techniques: color Schlieren and Mie-scatter. Schlieren captures density gradients in a spray which includes both liquid and vapor phases while Mie-scatter is only sensitive to the liquid phase of the fuel spray. Essentially, studies are mainly focused on extracting the liquid boundary from the Schlieren to possibly eliminate the need for acquiring the Mie-Scatter technique. Four test conditions (combination of low and high pressure and temperatures) are used in the application to attempt to find the liquid boundary independent of the Mie-scatter technique. In this pursuit the following methods were used: a color threshold, a value threshold, and the time variation in color. All methods provided some indication of the liquid region but none were able to capture the full liquid boundary as obtained by the Mie-scatter results. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

  10. ALICE HLT high speed tracking on GPU

    CERN Document Server

    Gorbunov, Sergey; Aamodt, Kenneth; Alt, Torsten; Appelshauser, Harald; Arend, Andreas; Bach, Matthias; Becker, Bruce; Bottger, Stefan; Breitner, Timo; Busching, Henner; Chattopadhyay, Sukalyan; Cleymans, Jean; Cicalo, Corrado; Das, Indranil; Djuvsland, Oystein; Engel, Heiko; Erdal, Hege Austrheim; Fearick, Roger; Haaland, Oystein Senneset; Hille, Per Thomas; Kalcher, Sebastian; Kanaki, Kalliopi; Kebschull, Udo Wolfgang; Kisel, Ivan; Kretz, Matthias; Lara, Camillo; Lindal, Sven; Lindenstruth, Volker; Masoodi, Arshad Ahmad; Ovrebekk, Gaute; Panse, Ralf; Peschek, Jorg; Ploskon, Mateusz; Pocheptsov, Timur; Ram, Dinesh; Rascanu, Theodor; Richter, Matthias; Rohrich, Dieter; Ronchetti, Federico; Skaali, Bernhard; Smorholm, Olav; Stokkevag, Camilla; Steinbeck, Timm Morten; Szostak, Artur; Thader, Jochen; Tveter, Trine; Ullaland, Kjetil; Vilakazi, Zeblon; Weis, Robert; Yin, Zhong-Bao; Zelnicek, Pierre

    2011-01-01

    The on-line event reconstruction in ALICE is performed by the High Level Trigger, which should process up to 2000 events per second in proton-proton collisions and up to 300 central events per second in heavy-ion collisions, corresponding to an inp ut data stream of 30 GB/s. In order to fulfill the time requirements, a fast on-line tracker has been developed. The algorithm combines a Cellular Automaton method being used for a fast pattern recognition and the Kalman Filter method for fitting of found trajectories and for the final track selection. The tracker was adapted to run on Graphics Processing Units (GPU) using the NVIDIA Compute Unified Device Architecture (CUDA) framework. The implementation of the algorithm had to be adjusted at many points to allow for an efficient usage of the graphics cards. In particular, achieving a good overall workload for many processor cores, efficient transfer to and from the GPU, as well as optimized utilization of the different memories the GPU offers turned out to be cri...

  11. Modern trends in designing high-speed trains

    OpenAIRE

    Golubović Snežana D.; Rašuo Boško P.; Lučanin Vojkan J.

    2015-01-01

    Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains. Not only do these types of trains comply with the need for increased speed of transportation and make the duration of the journey shorter, but they also meet the demands for increased reliability, safety and direct application of energy efficiency to the transportation system itself...

  12. Study on the subgrade deformation under high-speed train loading and water-soil interaction

    Science.gov (United States)

    Han, Jian; Zhao, Guo-Tang; Sheng, Xiao-Zhen; Jin, Xue-Song

    2016-04-01

    It is important to study the subgrade characteristics of high-speed railways in consideration of the water-soil coupling dynamic problem, especially when high-speed trains operate in rainy regions. This study develops a nonlinear water-soil interaction dynamic model of slab track coupling with subgrade under high-speed train loading based on vehicle-track coupling dynamics. By using this model, the basic dynamic characteristics, including water-soil interaction and without water induced by the high-speed train loading, are studied. The main factors-the permeability coefficient and the porosity-influencing the subgrade deformation are investigated. The developed model can characterize the soil dynamic behaviour more realistically, especially when considering the influence of water-rich soil.

  13. High speed bending of 2nd level interconnects on printed circuit boards for automotive electronics

    NARCIS (Netherlands)

    Kouters, M.H.M.; Ubachs, R.; Wiel, H.J. van de; Waal, A. van der; Veer, J. van der

    2011-01-01

    Standard drop tests for portable electronics are not representative for the qualification of automotive electronics. High-frequency vibrations are more dominant than abrupt shocks during normal operation. In this work a high speed board bending (HSB) method is developed to mimic the constant cyclic

  14. High-speed, image-based eye tracking with a scanning laser ophthalmoscope

    NARCIS (Netherlands)

    Sheehy, C.K.; Yang, Q.; Arathorn, D.W.; Teeruveedhula, P.; de Boer, J.F.; Roorda, A.J.

    2012-01-01

    We demonstrate a high-speed, image-based tracking scanning laser ophthalmoscope (TSLO) that can provide high fidelity structural images, real-time eye tracking and targeted stimulus delivery. The system was designed for diffraction-limited performance over an 8° field of view (FOV) and operates with

  15. Extremely high-speed imaging based on tubeless technology

    Science.gov (United States)

    Li, Jingzhen

    2008-11-01

    This contribution focuses on the tubeless imaging, the extreme-high speed imaging. A detail discussion is presented on how and why to make them, which would be the most important in the high speed imaging field in the future. Tubeless extreme-high speed imaging can not only be used to observe the transient processes like collision, detonating, and high voltage discharge, but also to research the processes like disintegration and transfer of phonon and exacton in solid, photosynthesis primitive reaction, and electron dynamics inside atom shell. Its imaging frequency is about 107~1015fps. For this kind of imaging, the mechanism of how forming both high speed and framing would better make fine use of the light speed, the light parallelism, the parameters of light wave such as its amplitude, phase, polarization and wave length, and even quantum characteristics of photons. In the cascade connection system of electromagnetic wave and particle wave, it is able to simultaneously realize high level both the temporal resolution and the spatial resolution, and it would be possible to break through the limit of the Heisenberg uncertainty correlation of the optical frequency band.

  16. Assessment of rural soundscapes with high-speed train noise.

    Science.gov (United States)

    Lee, Pyoung Jik; Hong, Joo Young; Jeon, Jin Yong

    2014-06-01

    In the present study, rural soundscapes with high-speed train noise were assessed through laboratory experiments. A total of ten sites with varying landscape metrics were chosen for audio-visual recording. The acoustical characteristics of the high-speed train noise were analyzed using various noise level indices. Landscape metrics such as the percentage of natural features (NF) and Shannon's diversity index (SHDI) were adopted to evaluate the landscape features of the ten sites. Laboratory experiments were then performed with 20 well-trained listeners to investigate the perception of high-speed train noise in rural areas. The experiments consisted of three parts: 1) visual-only condition, 2) audio-only condition, and 3) combined audio-visual condition. The results showed that subjects' preference for visual images was significantly related to NF, the number of land types, and the A-weighted equivalent sound pressure level (LAeq). In addition, the visual images significantly influenced the noise annoyance, and LAeq and NF were the dominant factors affecting the annoyance from high-speed train noise in the combined audio-visual condition. In addition, Zwicker's loudness (N) was highly correlated with the annoyance from high-speed train noise in both the audio-only and audio-visual conditions. © 2013.

  17. Evaluation of sounds for hybrid and electric vehicles operating at low speed

    Science.gov (United States)

    2012-10-22

    Electric vehicles (EV) and hybrid electric vehicles (HEVs), operated at low speeds may reduce auditory cues used by pedestrians to assess the state of nearby traffic creating a safety issue. This field study compares the auditory detectability of num...

  18. Submonolayer Quantum Dots for High Speed Surface Emitting Lasers

    Directory of Open Access Journals (Sweden)

    Zakharov ND

    2007-01-01

    Full Text Available AbstractWe report on progress in growth and applications of submonolayer (SML quantum dots (QDs in high-speed vertical-cavity surface-emitting lasers (VCSELs. SML deposition enables controlled formation of high density QD arrays with good size and shape uniformity. Further increase in excitonic absorption and gain is possible with vertical stacking of SML QDs using ultrathin spacer layers. Vertically correlated, tilted or anticorrelated arrangements of the SML islands are realized and allow QD strain and wavefunction engineering. Respectively, both TE and TM polarizations of the luminescence can be achieved in the edge-emission using the same constituting materials. SML QDs provide ultrahigh modal gain, reduced temperature depletion and gain saturation effects when used in active media in laser diodes. Temperature robustness up to 100 °C for 0.98 μm range vertical-cavity surface-emitting lasers (VCSELs is realized in the continuous wave regime. An open eye 20 Gb/s operation with bit error rates better than 10−12has been achieved in a temperature range 25–85 °Cwithout current adjustment. Relaxation oscillations up to ∼30 GHz have been realized indicating feasibility of 40 Gb/s signal transmission.

  19. New Drive Train Concept with Multiple High Speed Generator

    Science.gov (United States)

    Barenhorst, F.; Serowy, S.; Andrei, C.; Schelenz, R.; Jacobs, G.; Hameyer, K.

    2016-09-01

    In the research project RapidWind (financed by the German Federal Ministry for Economic Affairs and Energy under Grant 0325642) an alternative 6 MW drive train configuration with six high-speed (n = 5000 rpm) permanent magnet synchronous generators for wind turbine generators (WTG) is designed. The gearbox for this drive train concept is assembled with a six fold power split spur gear stage in the first stage, followed by six individual 1 MW geared driven generators. Switchable couplings are developed to connect and disconnect individual geared generators depending on the input power. With this drive train configuration it is possible to improve the efficiency during partial load operation, increasing the energy yield about 1.15% for an exemplary low-wind site. The focus of this paper is the investigation of the dynamic behavior of this new WTG concept. Due to the high gear ratio the inertia relationship between rotor and generator differs from conventional WT concepts, possibly leading to intensified vibration behavior. Moreover there are switching procedures added, that might also lead to vibration issues.

  20. HDR {sup 192}Ir source speed measurements using a high speed video camera

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Viana, Rodrigo S. S.; Yoriyaz, Hélio [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Podesta, Mark [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Rubo, Rodrigo A.; Sales, Camila P. de [Hospital das Clínicas da Universidade de São Paulo—HC/FMUSP, São Paulo 05508-000 (Brazil); Reniers, Brigitte [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Research Group NuTeC, CMK, Hasselt University, Agoralaan Gebouw H, Diepenbeek B-3590 (Belgium); Verhaegen, Frank, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec H3G 1A4 (Canada)

    2015-01-15

    Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

  1. High-sensitivity, high-speed continuous imaging system

    Science.gov (United States)

    Watson, Scott A; Bender, III, Howard A

    2014-11-18

    A continuous imaging system for recording low levels of light typically extending over small distances with high-frame rates and with a large number of frames is described. Photodiode pixels disposed in an array having a chosen geometry, each pixel having a dedicated amplifier, analog-to-digital convertor, and memory, provide parallel operation of the system. When combined with a plurality of scintillators responsive to a selected source of radiation, in a scintillator array, the light from each scintillator being directed to a single corresponding photodiode in close proximity or lens-coupled thereto, embodiments of the present imaging system may provide images of x-ray, gamma ray, proton, and neutron sources with high efficiency.

  2. Thermal Behavior of High-Speed Helical Gear Trains Investigated

    Science.gov (United States)

    Handschuh, Robert F.

    2003-01-01

    High-speed and heavily loaded gearing are commonplace in the rotorcraft systems employed in helicopter and tiltrotor transmissions. The components are expected to deliver high power from the gas turbine engines to the high-torque, low-speed rotor, reducing the shaft rotational speed in the range of 25:1 to 100:1. These components are designed for high power-to-weight ratios, thus the components are fabricated as light as possible with the best materials and processing to transmit the required torque and carry the resultant loads without compromising the reliability of the drive system. This is a difficult task that is meticulously analyzed and thoroughly tested experimentally prior to being applied on a new or redesigned aircraft.

  3. High-Performance Operating Systems

    DEFF Research Database (Denmark)

    Sharp, Robin

    1999-01-01

    Notes prepared for the DTU course 49421 "High Performance Operating Systems". The notes deal with quantitative and qualitative techniques for use in the design and evaluation of operating systems in computer systems for which performance is an important parameter, such as real-time applications......, communication systems and multimedia systems....

  4. Tactile shoe inlays for high speed pressure monitoring

    DEFF Research Database (Denmark)

    Drimus, Alin; Mátéfi-Tempfli, Stefan

    2015-01-01

    pressure sensitive cells and the use of high speed electronics and multiplexing algorithms provides frame rates of 100 Hz. The sensors tolerate overloads while showing a consistent output. The developed prototypes show a high potential not only for robotics, but also for use in sensorised human prosthetics....

  5. High-speed T-38A landing gear extension loads

    Science.gov (United States)

    Schmitt, A. L.

    1980-01-01

    Testing of T-38A landing gear extension at high speed and high altitude is described. The mechanisms are shown together with peak hydraulic pressure data during landing gear deployment with active and inactive strut door flaps. Results of strain gage measurements of stress on various structural members are included.

  6. Improving the Efficiency of a High Speed Catamaran Through the Replacement of the Propulsion System

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez

    2015-12-01

    Full Text Available The high speed vessels are primarily designed for short distances services as public transport of passengers and vehicles. The range of high speed, according to the Code of high-speed vessels begins at 20 knots, which depends on the cruise speed you desire for your vessel; you will have to use the most appropriate type of propellant. In general, in the past 20 years, they have been building high-speed vessels with speeds above 33 knots, which meant installing water jet propellants coupled to powerful engines and therefore of high consumption of fuel, increasing operating costs and causing increased air pollution. Although the prices of fuel have been reduced to half, due to the sharp fall in oil prices, the consumption of fuel and the air pollution remains high at these speeds and powers used, in addition to that the reduction of the time spent on each trip is not excessive, mainly in short routes that are less than an hour . This article is about adapting a ship of high-speed service, with a maximum speed in tests of 34 knots and to reduce its operating costs (fuel, maintenance, etc. and make it economically viable; before the transformation, this vessel was operating with a service speed of 22 knots, and with a consumption per mile of 135 litters of MGO. The transformation process has consisted by: – Replacement of the two original water jet with four shaft lines with fix pitch propeller. – Replacement of the two original main engines (2 x 6500 kW = 13000 kW by four engines (4 x 1380kW = 5.520 kW. – Changing the underwater hull shape to fit the new propellers and maximize its efficiency. – Relocation of auxiliary engines, to achieve the most efficient trim. – Installation of two lateral propellers to improve maneuverability and shorten the total time of journey. After the reform and the return to service of the vessel with a service speed of over 22 knots, it has been verified that the consumption per mile is of 45 litters MGO

  7. Research on high-speed railway's vibration analysis checking based on intelligent mobile terminal

    Science.gov (United States)

    Li, Peigang; Xie, Shulin; Zhao, Xuefeng

    2017-04-01

    Recently, the development of high-speed railway meets the requirement of society booming and it has gradually become the first choice for long-length journey. Since ensuring the safety and stable operation are of great importance to high-speed trains owing to its unique features, vibration analysis checking is one of main means to be adopted. Due to the popularization of Smartphone, in this research, a novel public-participating method to achieve high-speed railway's vibration analysis checking based on smartphone and an inspection application of high-speed railway line built in the intelligent mobile terminal were proposed. Utilizing the accelerometer, gyroscope, GPS and other high-performance sensors which were integrated in smartphone, the application can obtain multiple parameters like acceleration, angle, etc and pinpoint the location. Therefore, through analyzing the acceleration data in time domain and frequency domain using fast Fourier transform, the research compared much of data from monitoring tests under different measure conditions and measuring points. Furthermore, an idea of establishing a system about analysis checking was outlined in paper. It has been validated that the smartphone-based high-speed railway line inspection system is reliable and feasible on the high-speed railway lines. And it has more advantages, such as convenience, low cost and being widely used. Obviously, the research has important practical significance and broad application prospects.

  8. RPC operation at high temperature

    CERN Document Server

    Aielli, G; Cardarelli, R; Di Ciaccio, A; Di Stante, L; Liberti, B; Paoloni, A; Pastori, E; Santonico, R

    2003-01-01

    The resistive electrodes of RPCs utilised in several current experiments (ATLAS, CMS, ALICE, BABAR and ARGO) are made of phenolic /melaminic polymers, with room temperature resistivities ranging from 10**1**0 Omega cm, for high rate operation in avalanche mode, to 5 multiplied by 10**1**1 Omega cm, for streamer mode operation at low rate. The resistivity has however a strong temperature dependence, decreasing exponentially with increasing temperature. We have tested several RPCs with different electrode resistivities in avalanche as well as in streamer mode operation. The behaviours of the operating current and of the counting rate have been studied at different temperatures. Long-term operation has also been studied at T = 45 degree C and 35 degree C, respectively, for high and low resistivity electrodes RPCs.

  9. Entrainment characteristics of fine particles under high speed airflow

    Directory of Open Access Journals (Sweden)

    Yin Shaowu

    2017-01-01

    Full Text Available Fine silicon particles (mean size of 2.7 μm are used as entrained materials, and the entrainment characteristics of fine particles are investigated in a cylindrical fluidized-bed (inner diameter of 28 mm and height of 1000 mm under high speed airflow. The effects of the volume flow of gas (Q, 1 m3/h to 2.5 m3/h, the number of holes (N, 1 to 4, the size of holes (D, 1 mm to 3 mm, and the distance between holes and the upper surface of the material layer (H, -100 mm to 200 mm on the entrainment characteristics (entrainment rate W and entrained powder-gas ratio R are experimentally studied through orthogonal experiment. The experimental results show that an increase in Q and H constantly improves the entrainment characteristics; a decrease in D enhances such characteristics, whereas the number of holes N has no significant effect on the entrainment characteristics. An optimal operating condition can result in optimal entrainment characteristics (W, 3.1 g/min and R, 0.058 g/g, which can be achieved with a Q of 2.5 m3/h, N of 1, D of 2 mm and H of 200 mm.

  10. Increasing the life of high-speed steel cutting tools

    Energy Technology Data Exchange (ETDEWEB)

    Plyusnin, Y.G.

    1984-05-01

    The paper describes work on determining the rational area of use, mastering of production operations, and introduction into the plants of the industry of various methods of increasing the life of high-speed tools. Among these methods are carbonitriding, treatment of the tool by shock cooling and by application of a magnetic field, and the application of wear resistant coatings by the method of cathodic-ionic bombardment. The article briefly characterizes each method. Experience in the introduction of the carbonitriding process has shown that the greatest increase in life is obtained for relatively large cutting tools such as hubs and large diameter drills. The effectiveness of shock cooling depends to a great degree upon the original structure of the tool material and upon the requirements imposed on it in service (for stability). Experience in the magnetic treatment of drills and end mills up to 30mm in diameter has shown that the life of a magnetically treated tool with subsequent demagnetization increases by 1.2-1.4 times and without demagnetization by 1.7-2 times. The effectiveness of magnetic hardening depends not only upon the correctly selected strength of the magnetic field and time of application, but also upon the time of postmagnetic aging. Wear resistant coatings applied by the cathodic-ionic bombardment method increases by 2-5 times the life of a cutting tool. However, careful preparation of the tool surface is required as well as careful control of the temperature and thickness of the coating.

  11. Method for high-speed Manchester encoded optical signal generation

    DEFF Research Database (Denmark)

    Zhang, Jianfeng; Chi, Nan; Holm-Nielsen, Pablo Villanueva

    2004-01-01

    A method for high-speed Manchester encoded optical signal generation is proposed and demonstrated with a specially configured electro-optical modulator. A 10 Gb/s Manchester encoded optical signal was generated, and its bit-error-ratio (BER) performance was evaluated.......A method for high-speed Manchester encoded optical signal generation is proposed and demonstrated with a specially configured electro-optical modulator. A 10 Gb/s Manchester encoded optical signal was generated, and its bit-error-ratio (BER) performance was evaluated....

  12. Miniature high speed compressor having embedded permanent magnet motor

    Science.gov (United States)

    Zhou, Lei (Inventor); Zheng, Liping (Inventor); Chow, Louis (Inventor); Kapat, Jayanta S. (Inventor); Wu, Thomas X. (Inventor); Kota, Krishna M. (Inventor); Li, Xiaoyi (Inventor); Acharya, Dipjyoti (Inventor)

    2011-01-01

    A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing supports.

  13. Research and Development of High-speed Laser Scanning Galvanometer System

    Directory of Open Access Journals (Sweden)

    Chao-Ching Ho

    2013-12-01

    Full Text Available This study developed and controlled laser scanning mechanism and circuit design, in order to reduce the vibratory magnitude resulted from high-speed operation. The principle of mechanism design is that the output end mirror can swing within ± 3° when the laser scanning mechanism is in operation, the accuracy value is ± 0.2°. The static simulation and dynamic measurement were carried out for mutual validation. The vibration generated in the operation of machine causes dynamic unbalance, influencing the stability of machine. In order to overcome and improve the dynamic unbalance generated when the mechanism is in motion, different solutions were proposed, such as changing the output end mass, to add elastic material in or to change constant speed control of input end motor to variable speed control.

  14. Study on transient hydrodynamic performance and cavitation characteristic of high-speed mixed-flow pump

    Science.gov (United States)

    Chen, T.; Sun, Y. B.; Liu, Y. L.; Wu, D. Z.; Wang, L. Q.

    2013-12-01

    In order to analyse the hydrodynamic performance and cavitation characteristic of a high-speed mixed-flow pump during transient operations, experimental studies were carried out. The transient hydrodynamic performance and cavitation characteristics of the mixed-flow pump with guide vane during start-up operation processes were tested on the pump performance test-bed. Performance tests of the pump were carried out under various inlet pressures and speed-changing operations. The real-time instantaneous external characteristics such as rotational speed, hydraulic head, flow rate, suction pressure and discharge pressure of the pump were measured. Based on the experimental results, the effect of fluid acceleration on the hydrodynamic performances and cavitation characteristics of the mixed-flow pump were analysed and evaluated.

  15. Effects of high sound speed confiners on ANFO detonations

    Science.gov (United States)

    Kiyanda, Charles; Jackson, Scott; Short, Mark

    2011-06-01

    The interaction between high explosive (HE) detonations and high sound speed confiners, where the confiner sound speed exceeds the HE's detonation speed, has not been thoroughly studied. The subsonic nature of the flow in the confiner allows stress waves to travel ahead of the main detonation front and influence the upstream HE state. The interaction between the detonation wave and the confiner is also no longer a local interaction, so that the confiner thickness now plays a significant role in the detonation dynamics. We report here on larger scale experiments in which a mixture of ammonium nitrate and fuel oil (ANFO) is detonated in aluminium confiners with varying charge diameter and confiner thickness. The results of these large-scale experiments are compared with previous large-scale ANFO experiments in cardboard, as well as smaller-scale aluminium confined ANFO experiments, to characterize the effects of confiner thickness.

  16. Defect visualization in FRP-bonded concrete by using high speed camera and motion magnification technique

    Science.gov (United States)

    Qiu, Qiwen; Lau, Denvid

    2017-04-01

    High speed camera has the unique capacity of recording fast-moving objects. By using the video processing technique (e.g. motion magnification), the small motions recorded by the high speed camera can be visualized. Combined use of video camera and motion magnification technique is strongly encouraged to inspect the structures from a distant scene of interest, due to the commonplace availability, operational convenience, and cost-efficiency. This paper presents a non-contact method to evaluate the defect in FRP-bonded concrete structural element based on the surface motion analysis of high speed video. In this study, an instant air pressure is used to initiate the vibration of FRP-bonded concrete and cause the distinct vibration for the interfacial defects. The entire structural surface under the air pressure is recorded by a high-speed camera and the surface motion in video is amplified by motion magnification processing technique. The experimental results demonstrate that motion in the interfacial defect region can be visualized in the high-speed video with motion magnification. This validates the effectiveness of the new NDT method for defect detection in the whole composites structural member. The use of high-speed camera and motion magnification technique has the advantages of remote detection, efficient inspection, and sensitive measurement, which would be beneficial to structural health monitoring.

  17. Novel Model to Predict Minimum Coating Thickness for High Speed Slot Coating

    Science.gov (United States)

    Jang, Ilhoon; Song, Simon

    2012-11-01

    Recently slot coating is often applied to printed electronics for a flat display and in battery industry due to advantages such as the fast production rate and cost effectiveness. The accurate prediction of minimum coating thickness, closely related to coating stability, is a key issue in slot coating. It is because trial-and-error should be minimized when determining operating conditions of slot coating of which inks with metallic nano-particles are very expensive. So far, the viscocapillay model is known to provide good physical insight in a range of a low or moderate coating speed. However, its predictions are inaccurate for high coating speed since it doesn't consider the inertia of the ink flow arising at the high speed coating. In this study, we propose a novel model which accounts for the inertial effects. We performed detailed numerical analysis on ink flows of a slot coating to find out the cause of inaccurate prediction at a high speed coating and minimum coating thicknesses under various operating conditions. We found that the novel model prediction and numerical results are in excellent agreement in a wide coating speed range and that the new model can be applicable to an operating Reynolds number of an order higher than the viscocapillary model.

  18. Nanopatterned Quantum Dot Lasers for High Speed, High Efficiency, Operation

    Science.gov (United States)

    2015-04-27

    Jiming, et al. "Optical properties of rotationally twinned InP nanowire heterostructures ." Nano letters 8.3 (2008): 836-841. 19. Shtrikman, Hadas, et...confinement heterostructure (SCH) as shown in Fig 7. 1.5μm thick n: InP( 5 × 1017cm−3) and 150nm thick InGaAsP( λg = 1.15μm) lattice-matched to InP...context of nanowire (NW) growth in the literature, originated from the coexistence of zinc blende(ZB) and wurtzite(WZ) crystal structure when grown

  19. A multidimensional examination of performances of HSR (High-speed rail) systems

    NARCIS (Netherlands)

    Janic, M.

    2016-01-01

    This paper deals with a multidimensional examination of the infrastructural, technical/technological, operational, economic, social, and environmental performances of high-speed rail (HSR) systems, including their overview, analysis of some real-life cases, and limited (analytical) modeling. The

  20. Identification of high-speed rail ballast flight risk factors and risk mitigation strategies - final report.

    Science.gov (United States)

    2015-04-01

    The phenomenon of flying ballast is well-documented in high-speed rail operations. Displaced ballast particles from the track bed : may cause damage to rolling stock as well as the track infrastructure, and wayside structures close to the right of wa...

  1. High speed forging of solid powder discs of large slenderness ratio

    Indian Academy of Sciences (India)

    The paper reports an investigation into the forging of a solid powder circular disc with large slenderness ratio (L/D) between two flat dies at high speed. The deformation pattern during the operation is influenced by many factors, which interact with one another in a complex manner. The decisive factors are the interfacial ...

  2. Fatigue resistance of welded joints in aluminium high-speed craft : A total stress concept

    NARCIS (Netherlands)

    Den Besten, J.H.

    2015-01-01

    Crew transfers, surveillance duties and {security, rescue, interception} operations at sea typically require high-speed craft. Aluminium is quite often selected as hull structure material because of its weight save potential in comparison to steel. The fatigue strength, however, may become a point

  3. Recent Advances in Ultra-High-Speed Optical Signal Processing

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Palushani, Evarist; Hu, Hao

    2012-01-01

    We review recent advances in the optical signal processing of ultra-high-speed serial data signals up to 1.28 Tbit/s, with focus on applications of time-domain optical Fourier transformation. Experimental methods for the generation of symbol rates up to 1.28 Tbaud are also described....

  4. A high-speed interconnect network using ternary logic

    DEFF Research Database (Denmark)

    Madsen, Jens Kargaard; Long, S. I.

    1995-01-01

    This paper describes the design and implementation of a high-speed interconnect network (ICN) for a multiprocessor system using ternary logic. By using ternary logic and a fast point-to-point communication technique called STARI (Self-Timed At Receiver's Input), the communication between...

  5. High Speed Rail (HSR) in the United States

    Science.gov (United States)

    2009-12-08

    Magnetic Levitation (Maglev) ...............................................................................................5 High Speed Rail In...conventional steel wheel on steel rail technology, or magnetic levitation (in which superconducting magnets levitate a train above a guide rail...transported.14 Magnetic Levitation (Maglev) Maglev train technology was developed in the United States in the 1960s. It uses electromagnets to suspend

  6. Visualization of Projectile Flying at High Speed in Dusty Atmosphere

    Science.gov (United States)

    Masaki, Chihiro; Watanabe, Yasumasa; Suzuki, Kojiro

    2017-10-01

    Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in such environment was experimentally simulated by using the ballistic range. At high-speed collision of particles on the projectile surface, they may be reflected with cracking into smaller pieces. On the other hand, the projectile surface will be damaged by the collision. To obtain the fundamental characteristics of such complicated phenomena, a projectile was launched at the velocity up to 400 m/s and the collective behaviour of particles around projectile was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on only the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 400μm diameter were scattered and formed a sheet of particles in the test chamber by using two-dimensional funnel with a narrow slit. The projectile was launched into the particle sheet in the tangential direction, and the high-speed camera captured both projectile and particle motions. From the movie, the interaction between the projectile and particle sheet was clarified.

  7. Time-interleaved high-speed D/A converters

    NARCIS (Netherlands)

    Olieman, E.

    2016-01-01

    This thesis is on power efficient very high-speed digital-to-analog converters (DACs) in CMOS technology, intended to generate signals from DC to RF. Components in RF signal chains are nowadays often moved from the analog domain to the digital domain. This allows for more flexibility and better

  8. Bottom Raking Damage to High-Speed Craft

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    This paper presents a comparative study of the raking damage to high speed craft (HSC) and conventional ships. The analysis is based on a detailed theoretical model for the raking resistance of an assembled ship bottom structure and on the idea that the impact conditions for various ship types have...

  9. Research notes : high-speed rail survey results.

    Science.gov (United States)

    2010-08-01

    The survey was conducted from April 2010 to June 2010 using both a print and a web version with identical questions. The print version of the survey was distributed at open house meetings on high-speed rail held in Eugene, Junction City, Albany, Sale...

  10. The impact of high speed rail on airport competition

    NARCIS (Netherlands)

    Terpstra, I.; Lijesen, M.G.

    2015-01-01

    We study the effects of introducing a high speed train connection on competition between airports, focusing on the new HST-link between Amsterdam and Brussels. We conduct a detailed analysis regarding the airport choice of passengers living in the Netherlands, Belgium, Luxembourg, Northern France

  11. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

    Ghani, Arfan; Usmani, S. H.; Stassen, Flemming

    2004-01-01

    Static CMOS design displays benefits such as low power consumption, dominated by dynamic power consumption. In contrast, MOS Current Mode Logic (MCML) displays static rather than dynamic power consumption. High-speed low-power design is one of the many application areas in VLSI that require...

  12. High-speed photodiodes in standard CMOS technology

    NARCIS (Netherlands)

    Radovanovic, S.

    2004-01-01

    This thesis describes high-speed photodiodes in standard CMOS technology which allow monolithic integration of optical receivers for short-haul communication. The electronics for (multiple users) long-haul communication is very expensive (InP, GaAs), but the usage is justified by the large number of

  13. Optimization and performance of a high-speed plasma position ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 62; Issue 1. Optimization and performance of a high-speed plasma position digital control system. M Emami A R Babazadeh H Rasouli. Research Articles Volume 62 Issue 1 January 2004 pp 53-60 ...

  14. Faster than "g", Revisited with High-Speed Imaging

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter

    2012-01-01

    The introduction of modern high-speed cameras in physics teaching provides a tool not only for easy visualization, but also for quantitative analysis of many simple though fast occurring phenomena. As an example, we present a very well-known demonstration experiment--sometimes also discussed in the context of falling chimneys--which is commonly…

  15. High speed ultrafast laser surface processing (Conference Presentation)

    Science.gov (United States)

    Mincuzzi, Girolamo; Kling, Rainer; Lopez, John; Hoenninger, Clemens; Audouard, Eric; Mottay, Eric P.

    2017-03-01

    Surface functionalization is a rapidly growing application for industrial ultrafast lasers. There is an increasing interest for high throughput surface processing, especially for texturing and engraving large manufacturing tools for different industrial fields such as injection molding, embossing and printing. Hydrophobic and hydrophilic surfaces, colored or deep black metal surfaces can now be industrially produced. The engraving speed is continuously improving following improvements in beam scanning technology and high average power industrial ultrafast lasers. Several tenths of MHz for the laser repetition rate and several hundreds of meter per second for the beam speed are available. More than 100 m/s scanning speed is then possible for laser surface structuring. But these surfaces are quite hard to produce since it is necessary to have a good compromise between high removal rate and high surface quality (low roughness, burr-free, narrow heat affected zone). In this work, we apply a simple engineering model based on the two temperature description of ultra-fast ablation to estimate key processing parameters. In particular, the pulse-to-pulse overlap which depends on the scanning velocity, the spot size, and the laser repetition rate all have to be adjusted to optimize the depth and roughness, otherwise heat accumulation and heat affected zone may appear. Optimal sequences of time and spatial superposition of pulses are determined and applied with a polygonal scanner. Ablation depth and processing speed obtained are compared with experimental results.

  16. Optimization and performance of a high-speed plasma position ...

    Indian Academy of Sciences (India)

    a time domain of the order of few milliseconds. In order to achieve maximum performance it is essential to optimize the control system. In this paper plasma position measurement and the details of implementing high-speed PID controllers based on a TMS320c25 digital signal processor along with the system optimization ...

  17. Parallel and distributed processing in high speed traffic monitoring

    NARCIS (Netherlands)

    Cristea, Mihai Lucian

    2008-01-01

    This thesis presents a parallel and distributed approach for the purpose of processing network traffic at high speeds. The proposed architecture provides the processing power required to run one or more traffic processing applications at line rates by means of processing full packets at

  18. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    All these facts are the outcome of research on optical solitons in fibers in spite of the fact that the commonly used RZ format is not always called a soliton format. The overview presented here attempts to incorporate the role of soliton-based communications research in present day ultra-high speed communications.

  19. Investigations in high speed blanking: cutting forces and microscopic observations

    Directory of Open Access Journals (Sweden)

    Larue A.

    2010-06-01

    Full Text Available A new hopefull technique, called high speed blanking, has been investigated since few years. To understand the cutting process and how the tools have to be designed, this study is interrested in the cutting force measurement. A new cutting force measurement device has to be designed consider the industrial interest of such a study. The designed test bench induces a calibration process in order to stucy the cutting forces evolution. The paper is discussing the result that the peack load seems to decrease when the punch speed increases. Finally microscopic observations are made in order to find Adiabatic Shear Bands.

  20. Speed Acquisition Methods for High-Bandwidth Servo Drives

    OpenAIRE

    Bähr, Alexander

    2005-01-01

    A servo control needs the actual values of speed and position.Usually, the latter is computed from the signals of a position encoder; its 1st derivative is smoothed by a low-pass filter and used as actual speed signal. A number of enhanced and alternative methods is experimentally investigated in this thesis. Based on an equal steady-state behavior, the controlled servo's dynamic stiffness is used as the performance measure. The used setup has a special feature: because of its rather high res...

  1. Very High Speed Discrete Time Optical Signal Generation and Filtering

    Science.gov (United States)

    Narayan, Vishwa

    Optical lattice filters constitute a class of devices that generate and operate upon high bandwidth optical signals. This dissertation describes the design, analysis, construction and testing of such devices. We derive elegant z-transform based filter transfer functions and develop a convenient state variable based scattering matrix filter description. A variety of filters are designed and analyzed. We also design locally optimal optical lattice filters with mirror imperfections such as losses and finite reflectivity round-off error. We conduct a quantitative sensitivity analysis of the degrading effects of these imperfections on system performance, and study the distorting effects of phase error on pulse train shape. Experimentally, we use mirror based optical lattice filters to generate 667 GHz repetition rate pulse bursts with step and ramp envelopes, and coded pulse bursts. We also demonstrate the quadrupling and octupling of the 76 MHz repetition rate of a mode-locked laser. We demonstrate the low pass filtering property of optical lattice filters by realizing a high speed discrete time optical integrator. Step functions are integrated to ramps, and ramps to quadratics, at 667 GHz. We also constructed a mechanical variable repetition rate filter with a tuning range of 2.14 to 100 GHz. We design and analyze a gain based mirror filter with active gain elements. Small signal linear constant gain tends to improve filter performance by increasing the output, and reducing fluctuations in the frequency response. We study the behavior of these filters at the stability limit, characterized by large fluctuations in the frequency response. Optical lattice filters may be used as wavelength multiplexers/demultiplexers in lightwave systems, as variable repetition rate pulse train generators for tunable repetition rate optical spectroscopy, as optical clock generators, and as discrete time/analog optical signal filters.

  2. Imaging acoustic sources moving at high-speed

    Science.gov (United States)

    Bodony, Daniel; Papanicolaou, George

    2006-11-01

    In the quantification of the noise radiated by a turbulent flow the source motion is important. It is well known that moving acoustic sources radiate sound preferrentially in the direction of motion in a phenomenon termed `convective amplification.' Modern acoustic theories have utilized this behavior in their predictions. In the inverse problem the imaging of noise sources, by techniques such as beam forming, the source motion is not explicitly taken into account. In this talk we consider the imaging of acoustic sources moving at speeds on the order of the the ambient speed of sound, as typical of high-speed jets, for which the D"oppler shift approximation is not appropriate. An analysis will be presented that can be used to estimate the source motion based on the radiated acoustic field.

  3. Features of economic indicators calculation for high speed pilot boat on stage of conceptual design

    OpenAIRE

    Kleva, Yana A.

    2017-01-01

    During the last decades a vast amount of research has been focused on the issues of design, operations, and development of more optimized structures of high-speed craft. The right choice of the criterion function is crucial. Fundamentally, efficiency can be increased with the reduction of production costs, operational costs, and environmental impact, while maintaining or improving craft performance, reliability, and safety. The estimation of economic performances of pilot boats in conceptual ...

  4. Modeling Compressibility Effects in High-Speed Turbulent Flows

    Science.gov (United States)

    Sarkar, S.

    2004-01-01

    Man has strived to make objects fly faster, first from subsonic to supersonic and then to hypersonic speeds. Spacecraft and high-speed missiles routinely fly at hypersonic Mach numbers, M greater than 5. In defense applications, aircraft reach hypersonic speeds at high altitude and so may civilian aircraft in the future. Hypersonic flight, while presenting opportunities, has formidable challenges that have spurred vigorous research and development, mainly by NASA and the Air Force in the USA. Although NASP, the premier hypersonic concept of the eighties and early nineties, did not lead to flight demonstration, much basic research and technology development was possible. There is renewed interest in supersonic and hypersonic flight with the HyTech program of the Air Force and the Hyper-X program at NASA being examples of current thrusts in the field. At high-subsonic to supersonic speeds, fluid compressibility becomes increasingly important in the turbulent boundary layers and shear layers associated with the flow around aerospace vehicles. Changes in thermodynamic variables: density, temperature and pressure, interact strongly with the underlying vortical, turbulent flow. The ensuing changes to the flow may be qualitative such as shocks which have no incompressible counterpart, or quantitative such as the reduction of skin friction with Mach number, large heat transfer rates due to viscous heating, and the dramatic reduction of fuel/oxidant mixing at high convective Mach number. The peculiarities of compressible turbulence, so-called compressibility effects, have been reviewed by Fernholz and Finley. Predictions of aerodynamic performance in high-speed applications require accurate computational modeling of these "compressibility effects" on turbulence. During the course of the project we have made fundamental advances in modeling the pressure-strain correlation and developed a code to evaluate alternate turbulence models in the compressible shear layer.

  5. Transient flow characteristics of a high speed rotary valve

    Science.gov (United States)

    Browning, Patrick H.

    were experimentally mapped as a function of valve speed, inter-cylinder pressure ratios and volume ratios and the results were compared to compressible flow theoretical models. Specifically, the transient behavior suggested a short-lived loss-mode initiation closely resembled by shock tube theory followed by a quasi-steady flow regime resembling choked flow behavior. An empirical model was then employed to determine the useful range of the CCV design as applied to a four-stroke CIBAI engine cycle modeled using a 1-D quasi-steady numerical method, with particular emphasis on the cyclic timing of the CCV opening. Finally, a brief discussion of a high-temperature version of the CCV design is presented.

  6. Sound transmission loss of windows on high speed trains

    Science.gov (United States)

    Zhang, Yumei; Xiao, Xinbiao; Thompson, David; Squicciarini, Giacomo; Wen, Zefeng; Li, Zhihui; Wu, Yue

    2016-09-01

    The window is one of the main components of the high speed train car body structure through which noise can be transmitted. To study the windows’ acoustic properties, the vibration of one window of a high speed train has been measured for a running speed of 250 km/h. The corresponding interior noise and the noise in the wheel-rail area have been measured simultaneously. The experimental results show that the window vibration velocity has a similar spectral shape to the interior noise. Interior noise source identification further indicates that the window makes a contribution to the interior noise. Improvement of the window's Sound Transmission Loss (STL) can reduce the interior noise from this transmission path. An STL model of the window is built based on wave propagation and modal superposition methods. From the theoretical results, the window's STL property is studied and several factors affecting it are investigated, which provide indications for future low noise design of high speed train windows.

  7. Robust and Stable Disturbance Observer of Servo System for Low-Speed Operation

    DEFF Research Database (Denmark)

    Lee, Kyo Beum; Blaabjerg, Frede

    2007-01-01

    A new scheme to estimate the moment of inertia in the servo motor drive system in very low speed is proposed in this paper. The speed estimation scheme in most servo drive systems for low-speed operation is sensitive to the variation of machine parameter, especially the moment of inertia....... To estimate the motor inertia value, the observer using the Radial Basis Function Network (RBFN) is applied. A control law for stabilizing the system and adaptive laws for updating both of the weights in the RBFN and a bounding constant are established so that the whole closed-loop system is stable...

  8. Spectral domain optical coherence tomography - Ultra-high speed, ultra-high resolution ophthalmic imaging

    NARCIS (Netherlands)

    Chen, T.; Cense, B.; Pierce, M. C.; Nassif, N. A.; Park, B. H.; Yun, S. H.; White, B.; Bouma, B. E.; Tearney, G. J.; de Boer, J.F.

    2005-01-01

    Objective: To introduce a new ophthalmic optical coherence tomography technology that allows unprecedented simultaneous ultra-high speed and ultra-high resolution. Methods: Using a superluminescent diode source, a clinically viable ultra-high speed, ultra-high resolution spectral domain optical

  9. High speed tracking control of ball screw drives

    Science.gov (United States)

    Liu, Chao-Yi; Huang, Ruei-Yu; Lee, An-Chen

    2017-10-01

    This paper presents a new method to achieve the requirement of high speed and high precision for ball screw drive. First, a PI controller is adopted to increase the equivalent structural damping in the velocity loop. Next, the design of the position controller is implemented by a two-stage method. The Doubly Coprime Factorization Disturbance Observer (DCFDOB) is developed to suppress disturbance and resist modelling error in the inner loop, while the outer loop is then designed based on method to extend the system bandwidth over first resonant frequency so that high speed and high accuracy can be achieved. Finally, a feedforward controller is implemented to improve tracking performance. The experiment results showed that the proposed method has smaller tracking error and better performance for suppressing disturbance when compared to the conventional cascaded P-PI control.

  10. Ping-Pong Robotics with High-Speed Vision System

    DEFF Research Database (Denmark)

    Li, Hailing; Wu, Haiyan; Lou, Lei

    2012-01-01

    The performance of vision-based control is usually limited by the low sampling rate of the visual feedback. We address Ping-Pong robotics as a widely studied example which requires high-speed vision for highly dynamic motion control. In order to detect a flying ball accurately and robustly......, a multithreshold legmentation algorithm is applied in a stereo-vision running at 150Hz. Based on the estimated 3D ball positions, a novel two-phase trajectory prediction is exploited to determine the hitting position. Benefiting from the high-speed visual feedback, the hitting position and thus the motion planning...... of the manipulator are updated iteratively with decreasing error. Experiments are conducted on a 7 degrees of freedom humanoid robot arm. A successful Ping-Pong playing between the robot arm and human is achieved with a high successful rate of 88%....

  11. Development of Industrial High-Speed Transfer Parallel Robot

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung In; Kyung, Jin Ho; Do, Hyun Min; Jo, Sang Hyun [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2013-08-15

    Parallel robots used in industry require high stiffness or high speed because of their structural characteristics. Nowadays, the importance of rapid transportation has increased in the distribution industry. In this light, an industrial parallel robot has been developed for high-speed transfer. The developed parallel robot can handle a maximum payload of 3 kg. For a payload of 0.1 kg, the trajectory cycle time is 0.3 s (come and go), and the maximum velocity is 4.5 m/s (pick amp, place work, adept cycle). In this motion, its maximum acceleration is very high and reaches approximately 13g. In this paper, the design, analysis, and performance test results of the developed parallel robot system are introduced.

  12. Embedded systems design for high-speed data acquisition and control

    CERN Document Server

    Di Paolo Emilio, Maurizio

    2015-01-01

    This book serves as a practical guide for practicing engineers who need to design embedded systems for high-speed data acquisition and control systems. A minimum amount of theory is presented, along with a review of analog and digital electronics, followed by detailed explanations of essential topics in hardware design and software development. The discussion of hardware focuses on microcontroller design (ARM microcontrollers and FPGAs), techniques of embedded design, high speed data acquisition (DAQ) and control systems. Coverage of software development includes main programming techniques, culminating in the study of real-time operating systems. All concepts are introduced in a manner to be highly-accessible to practicing engineers and lead to the practical implementation of an embedded board that can be used in various industrial fields as a control system and high speed data acquisition system.   • Describes fundamentals of embedded systems design in an accessible manner; • Takes a problem-solving ...

  13. Preliminary Investigation of the Thermal Behavior of High-Speed Helical Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Kilmain, Charles J.

    2002-01-01

    A preliminary experimental investigation of the thermal behavior of high-speed helical gears will be presented. A full-scale torque regenerative test stand has been built to test a representative helical gear train as that used in tiltrotor aircraft. Power loss and temperature data from a wide range of operating conditions were measured. Loop power ranged up to 3730 kW (5000 hp). Drive system components representative of flight quality hardware were used in the test program. The results attained in this initial study indicated that windage losses due to the high rotational speeds that were tested were far more important than the losses due to the gear meshing losses.

  14. Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains.

    Directory of Open Access Journals (Sweden)

    Boliang Lin

    Full Text Available This paper presents a 0-1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China's high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers.

  15. Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains

    Science.gov (United States)

    Wang, Jiaxi; Wang, Huasheng; Wang, Zhongkai; Li, Jian; Lin, Ruixi; Xiao, Jie; Wu, Jianping

    2017-01-01

    This paper presents a 0–1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China’s high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers. PMID:28472097

  16. Twenty years of high-speed lines in Spain; Zwanzig Jahre Hochgeschwindigkeitsstrecken in Spanien

    Energy Technology Data Exchange (ETDEWEB)

    Vega Vega, Tomas [ADIF, Madrid (Spain); Gil Ortiz, Jose Miguel [Balfour Beatty Rail Iberica, Alcobendas (Spain)

    2012-07-15

    In April 1992, i.e. 20 years ago, fast train services started in Spain when high-speed trains were put into operation on the almost 500 km long Madrid-Cordoba-Sevilla railway line. Both the 1,435 mm UIC standard gauge and the 1 AC 25 kV 50 Hz overhead line voltage level meant a big step in the development. Today the Spanish high-speed network covers some 2,200 km of railway line, and more lines are planned or already under construction. (orig.)

  17. Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains.

    Science.gov (United States)

    Lin, Boliang; Wang, Jiaxi; Wang, Huasheng; Wang, Zhongkai; Li, Jian; Lin, Ruixi; Xiao, Jie; Wu, Jianping

    2017-01-01

    This paper presents a 0-1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China's high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers.

  18. High Speed Genetic Lips Detection by Dynamic Search Domain Control

    Science.gov (United States)

    Akashi, Takuya; Wakasa, Yuji; Tanaka, Kanya; Karungaru, Stephen; Fukumi, Minoru

    In this paper, high-speed size and orientation invariant lips detection of a talking person in an active scene using template matching and genetic algorithms is proposed. As part of the objectives, we also try to acquire numerical parameters to represent the lips. The information is very important for many applications, where high performance is required, such as audio-visual speech recognition, speaker identification systems, robot perception and personal mobile devices interfaces. The difficulty in lips detection is mainly due to deformations and geometric changes of the lips during speech and the active scene by free camera motion. In order to enhance the performance in speed and accuracy, initially, the performance is improved on a single still image, that is, the base of video processing. Our proposed system is based on template matching using genetic algorithms (GA). Only one template is prepared per experiment. The template is the closed mouth of a subject, because the application is for personal devices. In our previous study, the main problem was trade-off between search accuracy and search speed. To overcome this problem, we use two methods: scaling window and dynamic search domain control (SD-Control). We therefore focus on the population size of the GA, because it has a direct effect on search accuracy and speed. The effectiveness of the proposed system is demonstrated by performing computer simulations. We achieved a lips detection accuracy of 91.33% at an average processing time of 33.70 milliseconds per frame.

  19. A monolithic MEMS position sensor for closed-loop high-speed atomic force microscopy

    Science.gov (United States)

    Hosseini, N.; Nievergelt, A. P.; Adams, J. D.; Stavrov, V. T.; Fantner, G. E.

    2016-04-01

    The accuracy and repeatability of atomic force microscopy (AFM) imaging significantly depend on the accuracy of the piezoactuator. However, nonlinear properties of piezoactuators can distort the image, necessitating sensor-based closed-loop actuators to achieve high accuracy AFM imaging. The advent of high-speed AFM has made the requirements on the position sensors in such a system even more stringent, requiring higher bandwidths and lower sensor mass than traditional sensors can provide. In this paper, we demonstrate a way for high-speed, high-precision closed-loop AFM nanopositioning using a novel, miniaturized micro-electro-mechanical system position sensor in conjunction with a simple PID controller. The sensor was developed to respond to the need for small, lightweight, high-bandwidth, long-range and sub-nm-resolution position measurements in high-speed AFM applications. We demonstrate the use of this sensor for closed-loop operation of conventional as well as high-speed AFM operation to provide distortion-free images. The presented implementation of this closed-loop approach allows for positioning precision down to 2.1 Å, reduces the integral nonlinearity to below 0.2%, and allows for accurate closed loop imaging at line rates up to 300 Hz.

  20. Difference in muscle activation patterns during high-speed versus standard-speed yoga: A randomized sequence crossover study.

    Science.gov (United States)

    Potiaumpai, Melanie; Martins, Maria Carolina Massoni; Wong, Claudia; Desai, Trusha; Rodriguez, Roberto; Mooney, Kiersten; Signorile, Joseph F

    2017-02-01

    To compare the difference in muscle activation between high-speed yoga and standard-speed yoga and to compare muscle activation of the transitions between poses and the held phases of a yoga pose. Randomized sequence crossover trial SETTING: A laboratory of neuromuscular research and active aging Interventions: Eight minutes of continuous Sun Salutation B was performed, at a high speed versus a standard-speed, separately. Electromyography was used to quantify normalized muscle activation patterns of eight upper and lower body muscles (pectoralis major, medial deltoids, lateral head of the triceps, middle fibers of the trapezius, vastus medialis, medial gastrocnemius, thoracic extensor spinae, and external obliques) during the high-speed and standard-speed yoga protocols. Difference in normalized muscle activation between high-speed yoga and standard-speed yoga. Normalized muscle activity signals were significantly higher in all eight muscles during the transition phases of poses compared to the held phases (pyoga across the entire session. Our results show that transitions from one held phase of a pose to another produces higher normalized muscle activity than the held phases of the poses and that overall activity is greater during highspeed yoga than standard-speed yoga. Therefore, the transition speed and associated number of poses should be considered when targeting specific improvements in performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Holistic design in high-speed optical interconnects

    Science.gov (United States)

    Saeedi, Saman

    receiver sensitivity is measured to be -8.8dBm at 32Gb/s. Next, on the optical transmitter side, three new techniques will be presented. First one is a differential ring modulator that breaks the optical bandwidth/quality factor trade-off known to limit the speed of high-Q ring modulators. This structure maintains a constant energy in the ring to avoid pattern-dependent power droop. As a first proof of concept, a prototype has been fabricated and measured up to 10Gb/s. The second technique is thermal stabilization of micro-ring resonator modulators through direct measurement of temperature using a monolithic PTAT temperature sensor. The measured temperature is used in a feedback loop to adjust the thermal tuner of the ring. A prototype is fabricated and a closed-loop feedback system is demonstrated to operate at 20Gb/s in the presence of temperature fluctuations. The third technique is a switched-capacitor based pre-emphasis technique designed to extend the inherently low bandwidth of carrier injection micro-ring modulators. A measured prototype of the optical transmitter achieves energy efficiency of 342fJ/bit at 10Gb/s and the wavelength stabilization circuit based on the monolithic PTAT sensor consumes 0.29mW. Lastly, a first-order frequency synthesizer that is suitable for high-speed on-chip clock generation will be discussed. The proposed design features an architecture combining an LC quadrature VCO, two sample-and-holds, a PI, digital coarse-tuning, and rotational frequency detection for fine-tuning. In addition to an electrical reference clock, as an extra feature, the prototype chip is capable of receiving a low jitter optical reference clock generated by a high-repetition-rate mode-locked laser. The output clock at 8GHz has an integrated RMS jitter of 490fs, peak-to-peak periodic jitter of 2.06ps, and total RMS jitter of 680fs. The reference spurs are measured to be 64.3dB below the carrier frequency. At 8GHz the system consumes 2.49mW from a 1V supply.

  2. HIGH-SPEED HOT EXTRUSION IN HIGH TEMPERATURE MECHANICAL TREATMENT MODE OF BIMETALLIC ROD PARTS OF THE STAMPS

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2016-01-01

    Full Text Available Processes of high-speed shaping change and especially high-speed hot extrusion create efficient conditions for treatment of low plastic and difficult-to-form materials which are widely used in tool making production. Due to the fact that high-speed stamping provides accurate billets with increased mechanical properties, it can be used as a technological process for manufacturing rod parts of die tooling operating under the increased loads and high wear. The purpose of the paper is to carry out experimental investigation of the possibility to obtain bimetallic rod stamping tooling by high-speed hot extrusion in high-temperature mode treatment in order to save die steels and improve the quality of the products obtained. Microstructures of the bimetallic compounds obtained with the help of high-speed hot extrusion method for compositions of structural and high-alloy steels have been investigated and their high quality has been proved during the investigations. Dependences of micro-hardness distribution have been established outbound two steel contact plane in the zone of connection that are characterized by a minimum micro-hardness value in the connection joint. Availability of more plastic zone in the contact plane contributes to reduction of residual stresses due to their relaxation in this zone and higher joint strength. 

  3. Irregular GIS Curve Fitting based High Speed Railway Earthquake Influence Range Calculation Model

    Directory of Open Access Journals (Sweden)

    Hu Zhaobing

    2017-01-01

    Full Text Available In this paper, to guarantee that the train can take measures to reduce the damage caused by the earthquake, it propose an irregular GI S curve fitting based high-speed railway earthquake influence range calculation model. Firstly, this model eliminates the abnormal points, calculates feature points and finds demarcation points of the high- speed railway GI S curve to get the processed point collection in Mercator coordinate. Secondly, though usin g the processed point collection, this model applies least square polynomial segmentation fitting method to implement complex high-speed GI S curve fitting. Thirdly, calculate the earthquake influence rang on high-seed railway line, according to the scope of the earthquake equation and the high-speed railway GI S curve fitt ed equation. Finally, the paper selects the Beijing So uth to Dezhou East high-speed railway section which is part of Beijing-Shanghai line as a case study, which proves that the model can calculate the earthquake influence scope on the railway line offering decision support for train operation to ensure safety.

  4. High-speed atomic force microscopy combined with inverted optical microscopy for studying cellular events.

    Science.gov (United States)

    Suzuki, Yuki; Sakai, Nobuaki; Yoshida, Aiko; Uekusa, Yoshitsugu; Yagi, Akira; Imaoka, Yuka; Ito, Shuichi; Karaki, Koichi; Takeyasu, Kunio

    2013-01-01

    A hybrid atomic force microscopy (AFM)-optical fluorescence microscopy is a powerful tool for investigating cellular morphologies and events. However, the slow data acquisition rates of the conventional AFM unit of the hybrid system limit the visualization of structural changes during cellular events. Therefore, high-speed AFM units equipped with an optical/fluorescence detection device have been a long-standing wish. Here we describe the implementation of high-speed AFM coupled with an optical fluorescence microscope. This was accomplished by developing a tip-scanning system, instead of a sample-scanning system, which operates on an inverted optical microscope. This novel device enabled the acquisition of high-speed AFM images of morphological changes in individual cells. Using this instrument, we conducted structural studies of living HeLa and 3T3 fibroblast cell surfaces. The improved time resolution allowed us to image dynamic cellular events.

  5. Optical Amplication for Terabit-per-Second Ultra-High Speed Communication Systems

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh

    amplification response time and flexible operation spectral range, FOPAs are able to simultaneously operate as amplifiers and all-optical signal processors in high-speed Tbaud networks. In this thesis, we study the performance of FOPAs in detail in the linear and nonlinear (saturated) regimes where they can...... and saturation effect in order to assess the degradation of the amplified signal. In a very good agreement with the performed experiments, it is shown that the noise transferred to the signal can be effectively suppressed by operating in the saturation regime. The amplification of short few picosecond......The present thesis is concerned with fiber optical parametric amplification and regeneration for high-speed optical communication systems. Fiber optical parametric amplifiers (FOPAs) have multi-functional applications depending on their implementation in optical systems. Based on a few femtosecond...

  6. Quantification of the uncertainties of high-speed camera measurements

    Directory of Open Access Journals (Sweden)

    Robbe C.

    2014-01-01

    Full Text Available This article proposes a combined theoretical and experimental approach to assess and quantify the global uncertainty of a high-speed camera velocity measurement. The study is divided in five sections: firstly, different sources of measurement uncertainties performed by a high-speed camera are identified and quantified. They consist of geometrical uncertainties, pixel discretisation uncertainties or optical uncertainties. Secondly, a global uncertainty factor, taking into account the previously identified sources of uncertainties, is computed. Thirdly, a sensibility study of the camera set-up parameters is performed, allowing the experimenter to optimize these parameters in order to minimize the final uncertainties. Fourthly, the theoretical computed uncertainty is compared with experimental measurements. Good concordance has been found. Finally, the velocity measurement uncertainty study is extended to continuous displacement measurements as a function of time. The purpose of this article is to propose all the mathematical tools necessary to quantify the individual and global uncertainties, to highlight the important aspects of the experimental set-up, and to give recommendations on how to improve a specific set-up in order to minimize the global uncertainty. Taking all these into account, it has been shown that highly dynamic phenomena such as a ballistic phenomenon can be measured using a high-speed camera with a global uncertainty of less than 2%.

  7. Model Based Research of Dynamic Performance of Shaft-Bearing System in High-Speed Field

    Directory of Open Access Journals (Sweden)

    Teng Hu

    2014-01-01

    Full Text Available Dynamic performance of the high-speed running shaft-bearing system (SBS is different from that of idle state system due to the high-speed effects (HSE, including shaft centrifugal force, gyroscopic moment, and nonlinear bearing operational stiffness. In this paper, aiming at improving the operation stability, dynamic performance of SBS operating in high-speed field is investigated based on a finite element (FE dynamic model. Firstly, the Timoshenko beam elements are applied to develop the SBS FE model with full consideration of HSE. Secondly, idle state frequency response function at the front tip is obtained analytically and experimentally to validate that the FE model can illustrate the system dynamic behaviors in static condition. Finally, by substituting various rotational velocities into the FE model, the HSE on system natural frequencies are studied one by one as well as together. The results show that, when bearing is being extremely light preloaded, SBS frequencies are affected by the HSE of shaft more than bearing, especially where the gyroscopic moment effect of shaft is the most influential factor. Moreover, the nonmonotonic variation of bearing operational stiffness is analyzed. The “stiffen” phenomenon explained in this paper provides a more comprehensive understanding of the nonlinear bearing operational stiffness.

  8. Plasma Perturbations in High-Speed Probing of Hall Thruster Discharge Chambers: Quantification and Mitigation

    Science.gov (United States)

    Jorns, Benjamin A.; Goebel, Dan M.; Hofer, Richard R.

    2015-01-01

    An experimental investigation is presented to quantify the effect of high-speed probing on the plasma parameters inside the discharge chamber of a 6-kW Hall thruster. Understanding the nature of these perturbations is of significant interest given the importance of accurate plasma measurements for characterizing thruster operation. An array of diagnostics including a high-speed camera and embedded wall probes is employed to examine in real time the changes in electron temperature and plasma potential induced by inserting a high-speed reciprocating Langmuir probe into the discharge chamber. It is found that the perturbations onset when the scanning probe is downstream of the electron temperature peak, and that along channel centerline, the perturbations are best characterized as a downstream shift of plasma parameters by 15-20% the length of the discharge chamber. A parametric study is performed to investigate techniques to mitigate the observed probe perturbations including varying probe speed, probe location, and operating conditions. It is found that the perturbations largely disappear when the thruster is operated at low power and low discharge voltage. The results of this mitigation study are discussed in the context of recommended methods for generating unperturbed measurements of the discharge chamber plasma.

  9. High Speed Mobility Through On-Demand Aviation

    Science.gov (United States)

    Moore, Mark D.; Goodrich, Ken; Viken, Jeff; Smith, Jeremy; Fredericks, Bill; Trani, Toni; Barraclough, Jonathan; German, Brian; Patterson, Michael

    2013-01-01

    automobiles. ?? Community Noise: Hub and smaller GA airports are facing increasing noise restrictions, and while commercial airliners have dramatically decreased their community noise footprint over the past 30 years, GA aircraft noise has essentially remained same, and moreover, is located in closer proximity to neighborhoods and businesses. ?? Operating Costs: GA operating costs have risen dramatically due to average fuel costs of over $6 per gallon, which has constrained the market over the past decade and resulted in more than 50% lower sales and 35% less yearly operations. Infusion of autonomy and electric propulsion technologies can accomplish not only a transformation of the GA market, but also provide a technology enablement bridge for both larger aircraft and the emerging civil Unmanned Aerial Systems (UAS) markets. The NASA Advanced General Aviation Transport Experiments (AGATE) project successfully used a similar approach to enable the introduction of primary composite structures and flat panel displays in the 1990s, establishing both the technology and certification standardization to permit quick adoption through partnerships with industry, academia, and the Federal Aviation Administration (FAA). Regional and airliner markets are experiencing constant pressure to achieve decreasing levels of community emissions and noise, while lowering operating costs and improving safety. But to what degree can these new technology frontiers impact aircraft safety, the environment, operations, cost, and performance? Are the benefits transformational enough to fundamentally alter aircraft competiveness and productivity to permit much greater aviation use for high speed and On-Demand Mobility (ODM)? These questions were asked in a Zip aviation system study named after the Zip Car, an emerging car-sharing business model. Zip Aviation investigates the potential to enable new emergent markets for aviation that offer "more flexibility than the existing transportation solutions

  10. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false High-speed rail cars... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to those using “maglev” or high speed...

  11. High-speed measurement of firearm primer blast waves

    CERN Document Server

    Courtney, Michael; Eng, Jonathan; Courtney, Amy

    2012-01-01

    This article describes a method and results for direct high-speed measurements of firearm primer blast waves employing a high-speed pressure transducer located at the muzzle to record the blast pressure wave produced by primer ignition. Key findings are: 1) Most of the lead styphnate based primer models tested show 5.2-11.3% standard deviation in the magnitudes of their peak pressure. 2) In contrast, lead-free diazodinitrophenol (DDNP) based primers had standard deviations of the peak blast pressure of 8.2-25.0%. 3) Combined with smaller blast waves, these large variations in peak blast pressure of DDNP-based primers led to delayed ignition and failure to fire in brief field tests.

  12. Characterizing pyrotechnic igniter output with high-speed schlieren imaging

    Science.gov (United States)

    Skaggs, M. N.; Hargather, M. J.; Cooper, M. A.

    2017-01-01

    Small-scale pyrotechnic igniter output has been characterized using a high-speed schlieren imaging system for observing critical features of the post-combustion flow. The diagnostic, with laser illumination, was successfully applied towards the quantitative characterization of the output from Ti/KClO_4 and TiH_{1.65}/KClO_4 pyrotechnic igniters. The high-speed image sequences showed shock motion, burned gas expansion, and particle motion. A statistical-based analysis methodology for tracking the full-field shock motion enabled straightforward comparisons across the experimental parameters of pyrotechnic material and initial density. This characterization of the mechanical energy of the shock front within the post-combustion environment is a necessary addition to the large body of literature focused on pyrotechnic combustion behavior within the powder bed. Ultimately, understanding the role that the combustion behavior has on the resulting multiphase environment is required for tailored igniter development and comparative performance assessments.

  13. High-speed imaging polarimetry using liquid crystal modulators

    Directory of Open Access Journals (Sweden)

    Ambs P.

    2010-06-01

    Full Text Available This paper deals with dynamic polarimetric imaging techniques. The basics of modern polarimetry have been known for one and a half century, but no practical high-speed implementation providing the full polarization information is currently available. Various methods are reviewed which prove to be a trade-off between the complexity of the optical set-up and the amount of polarimetric information they provide (ie the number of components of the Stokes vector. Techniques using liquid crystal devices, incepted in the late 1990's, are emphasized. Optical set-ups we implemented are presented. We particularly focus on high-speed techniques (i.e. faster than 200 Hz using ferroelectric liquid crystal devices.

  14. Clinical application of high speed B mode echocardiography.

    Science.gov (United States)

    Kambe, T; Nishimura, K; Hibi, N; Sakakibara, T; Kato, T

    1977-06-01

    This study discusses the clinical application of high speed B mode echocardiography to a wide variety of heart diseases. We used a rapid mechanical sector scan at 30 frames per second and 120 scanning lines per frame, resulting in real time observation of cardiac structures. The sector angle was relatively wide (maximum 90 degrees). The tomograms were synchronized with the electrocardiogram and recorded on ordinary 35 mm or Polaroid film in conjunction with 8 mm cinematography. Heart cross sections could be recorded even in the presence of arrhythmia. We used a flat or focused, 10 mm diameter transducer made of lead zirconate-titanate with a resonant frequency of 2 or 3 MHz at a repetition rate of 3.6 kHz. High speed B mode echocardiography is a means of observing cross sections of the heart that can contribute to the improvement of accuracy in cardiac diagnosis.

  15. HIPO: a high-speed imaging photometer for occultations

    Science.gov (United States)

    Dunham, Edward W.; Elliot, James L.; Bida, Thomas A.; Taylor, Brian W.

    2004-09-01

    HIPO is a special purpose instrument for SOFIA, the Stratospheric Observatory For Infrared Astronomy. It is a high-speed, imaging photometer that will be used for a variety of time-resolved precise photometry observations, including stellar occultations by solar system objects and transits by extrasolar planets. HIPO has two independent CCD detectors and can also co-mount with FLITECAM, an InSb imager and spectrometer, making simultaneous photometry at three wavelengths possible. HIPO's flexible design and high-speed imaging capability make it well suited to carry out initial test observations on the completed SOFIA system, and to this end a number of additional features have been incorporated. Earlier papers have discussed the design requirements and optical design of HIPO. This paper provides an overview of the instrument, describes the instrument's features, and reviews the actual performance, in most areas, of the completed instrument.

  16. Embedded function methods for compressible high speed turbulent flow

    Science.gov (United States)

    Walker, J. D. A.

    1994-09-01

    This is the final report on the work performed on the grant 'Embedded Function Methods for Compressible High Speed Turbulent Flow' carried out at Lehigh University during the contract period from September, 1987, to October of 1991. Work has continued at Lehigh on this project on an unfunded basis to the present. The original proposed work had two separate thrusts which were associated with developing embedded function methods in order to obviate the need to expend computational resources on turbulent wall layers in Navier Stokes and boundary-layer calculations. Previous work on the incompressible problem had indicated that this could be done successfully for two-dimensional and three-dimensional incompressible flows. The central objective here was to extend the basic approach to the high speed compressible problem.

  17. High-Speed Coherent Raman Fingerprint Imaging of Biological Tissues

    CERN Document Server

    Camp, Charles H; Heddleston, John M; Hartshorn, Christopher M; Walker, Angela R Hight; Rich, Jeremy N; Lathia, Justin D; Cicerone, Marcus T

    2014-01-01

    We have developed a coherent Raman imaging platform using broadband coherent anti-Stokes Raman scattering (BCARS) that provides an unprecedented combination of speed, sensitivity, and spectral breadth. The system utilizes a unique configuration of laser sources that probes the Raman spectrum over 3,000 cm$^{-1}$ and generates an especially strong response in the typically weak Raman "fingerprint" region through heterodyne amplification of the anti-Stokes photons with a large nonresonant background (NRB) while maintaining high spectral resolution of $<$ 13 cm$^{-1}$. For histology and pathology, this system shows promise in highlighting major tissue components in a non-destructive, label-free manner. We demonstrate high-speed chemical imaging in two- and three-dimensional views of healthy murine liver and pancreas tissues and interfaces between xenograft brain tumors and the surrounding healthy brain matter.

  18. Comparison of high-speed rail and maglev systems

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, F.T. [Univ. of Florida, Gainesville, FL (United States). Dept. of Civil Engineering; Nassar, F.E. [Keith and Schnars, Fort Lauderdale, FL (United States)

    1996-07-01

    European and Japanese high-speed rail (HSR) and magnetically levitated (maglev) systems were each developed to respond to specific transportation needs within local economic, social, and political constraints. Not only is maglev technology substantially different from that of HSR, but also HSR and maglev systems differ in trainset design, track characteristics, cost structure, and cost sensitivity to design changes. This paper attempts to go beyond the traditional technology comparison table and focuses on the characteristics and conditions for which existing European and Japanese systems were developed. The technologies considered are the French train a grand vitesse (TGV), the Swedish X2000, the German Intercity Express (ICE) and Transrapid, and the Japanese Shinkansen, MLU, and high-speed surface train (HSST).

  19. Optical communication equalized technique suitable for high-speed transmission

    Science.gov (United States)

    Zhu, Yaolin; Guan, Hao

    2017-07-01

    To solve the phase distortion and high error rate in optical signal transmission, an equalized technique is proposed, which aims to improve the constant modulus algorithm (CMA). In order to correct phase rotating and reduce the error rate with 64 quadrature amplitude modulation (QAM), the method takes the mean square error as the judgment and utilizes the time-varying step size. Simulation results demonstrate that the proposed algorithm can improve the convergence speed of constellation points, make the eye opening larger, and the signal noise ratio (SNR) can be increased by 4 dB under the same bit error rate (BER), which is efficient for the recovery of information in high-speed transmission.

  20. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

  1. High-speed FPGA-based phase measuring profilometry architecture.

    Science.gov (United States)

    Zhan, Guomin; Tang, Hongwei; Zhong, Kai; Li, Zhongwei; Shi, Yusheng; Wang, Congjun

    2017-05-01

    This paper proposes a high-speed FPGA architecture for the phase measuring profilometry (PMP) algorithm. The whole PMP algorithm is designed and implemented based on the principle of full-pipeline and parallelism. The results show that the accuracy of the FPGA system is comparable with those of current top-performing software implementations. The FPGA system achieves 3D sharp reconstruction using 12 phase-shifting images and completes in 21 ms with 1024 × 768 pixel resolution. To the best of our knowledge, this is the first fully pipelined architecture for PMP systems, and this makes the PMP system very suitable for high-speed embedded 3D shape measurement applications.

  2. High-speed cell sorting: fundamentals and recent advances.

    Science.gov (United States)

    Ibrahim, Sherrif F; van den Engh, Ger

    2003-02-01

    Cell sorters have undergone dramatic technological improvements in recent years. Driven by the increased ability to differentiate between cell types, modern advances have yielded a new generation of cytometers, known as high-speed cell sorters. These instruments are capable of higher throughput than traditional sorters and can distinguish subtler differences between particles by measuring and processing more optical parameters in parallel. These advances have expanded their use to facilitate genomic and proteomic discovery, and as vehicles for many emerging cell-based therapies. High-speed cell sorting is becoming established as an essential research tool across a broad range of scientific fields and is poised to play a pivotal role in the latest therapeutic modalities.

  3. Numerical Investigation of Aerodynamic Characteristics of High Speed Train

    Science.gov (United States)

    Ali, J. S. Mohamed; Omar, Ashraf Ali; Ali, Muhammad ‘Atif B.; Baseair, Abdul Rahman Bin Mohd

    2017-03-01

    In this work, initially the effect of nose shape on the drag characteristics of a high speed train is studied. Then the influence of cross winds on the aerodynamics and hence the stability of such modern high speed trains is analyzed. CFD analysis was conducted using STAR-CCM+ on trains with different features and important aerodynamic coefficients such as the drag, side force and rolling moment coefficients have been calculated for yaw angles of crosswinds ranging from 0° to 90°. The results show that the modification on train nose shape can reduce the drag up to more than 50%. It was also found that, bogie faring only reduces small percentage of drag but significantly contributed to higher rolling moment and side force coefficient hence induced train instability.

  4. Robust adaptive cruise control of high speed trains.

    Science.gov (United States)

    Faieghi, Mohammadreza; Jalali, Aliakbar; Mashhadi, Seyed Kamal-e-ddin Mousavi

    2014-03-01

    The cruise control problem of high speed trains in the presence of unknown parameters and external disturbances is considered. In particular a Lyapunov-based robust adaptive controller is presented to achieve asymptotic tracking and disturbance rejection. The system under consideration is nonlinear, MIMO and non-minimum phase. To deal with the limitations arising from the unstable zero-dynamics we do an output redefinition such that the zero-dynamics with respect to new outputs becomes stable. Rigorous stability analyses are presented which establish the boundedness of all the internal states and simultaneously asymptotic stability of the tracking error dynamics. The results are presented for two common configurations of high speed trains, i.e. the DD and PPD designs, based on the multi-body model and are verified by several numerical simulations. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Analysis and design technology for high-speed aircraft structures

    Science.gov (United States)

    Starnes, James H., Jr.; Camarda, Charles J.

    1992-01-01

    Recent high-speed aircraft structures research activities at NASA Langley Research Center are described. The following topics are covered: the development of analytical and numerical solutions to global and local thermal and structural problems, experimental verification of analysis methods, identification of failure mechanisms, and the incorporation of analysis methods into design and optimization strategies. The paper describes recent NASA Langley advances in analysis and design methods, structural and thermal concepts, and test methods.

  6. Ocular Imaging Combining Ultrahigh Resolution and High Speed OCT

    Science.gov (United States)

    Schmoll, Tilman; Leitgeb, Rainer A.

    The impact of ultrahigh-resolution and ultrahigh-speed OCT technique on corneal and retinal imaging is shown. The capabilities of advanced OCT system for imaging of the cornea and the thickness determination of the tear film, corneal epithelium, and Bowman's layer over a wide field of view are demonstrated. The high transverse and axial resolution of OCT system allowing one to image individual nerve fiber bundles, the parafoveal capillary network, and individual cone photoreceptors is described.

  7. High-speed deformation processing of a titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Tamirisakandala, S.; Medeiros, S.C.; Malas, J.C. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433 (United States); Yellapregada, P.V.R.K. [Department of Metallurgy, Indian Institute of Science Bangalore, Karnataka 560 012 (India); Frazier, W.G. [NCPA Coliseum Drive, University, MS 38677 (United States); Dutta, B. [Department of Materials Science, Darmstadt University of Technology, Petersenstrasse 23, D-64287 Darmstadt (Germany)

    2003-09-01

    The deformation rate is the critical parameter for the phase transforming mechanism and subsequently the morphology of Ti-Al-V alloys, which in turn determines the feasibility of high-speed deformation. The evolution of defect-free equiaxed microstructures is due to dislocation-induced heterogeneous nucleation and growth. The Figure shows a microstructure of a Ti-6Al-4V specimen deformed at 1000 C in a backscattered SEM image. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  8. Design and specification of a high speed transport protocol

    OpenAIRE

    McArthur, Robert C.

    1992-01-01

    Approved for public release; distribution is unlimited Due to the increase in data throughput potential provided by high speed (fiber optic) networks, existing transport protocols are becoming increasingly incapable of providing reli­able and timely transfer of data. Whereas in networks of the past it was the transmission medium that caused the greatest communications delay, it is the case today that the transport protocols themselves have become the bottleneck. This thesis provides de...

  9. Study and improvement of a high speed hydraulic jack

    Science.gov (United States)

    Garcia, M. S.; Nouillant, M.; Viot, P.

    2006-08-01

    This paper describes the control problem of a high speed hydraulic jack. We shall estimate the performances of a servo-control with a classic controlled correction of type PD (Proportional Derivate). The study will be performed from a model (servo valve + jack + load), whose simulation will be performed in the Matlab-SimulinK environment. The aim of this article is to characterize, by simulating, the interdependence between the experimental apparatus and the tested object.

  10. Gearbox Reliability Collaborative High-Speed Shaft Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; McNiff, B.

    2014-09-01

    Instrumentation has been added to the high-speed shaft, pinion, and tapered roller bearing pair of the Gearbox Reliability Collaborative gearbox to measure loads and temperatures. The new shaft bending moment and torque instrumentation was calibrated and the purpose of this document is to describe this calibration process and results, such that the raw shaft bending and torque signals can be converted to the proper engineering units and coordinate system reference for comparison to design loads and simulation model predictions.

  11. On the reversed Brayton cycle with high speed machinery

    Energy Technology Data Exchange (ETDEWEB)

    Backman, J.

    1996-12-31

    This work was carried out in the laboratory of Fluid Dynamics, at Lappeenranta University of Technology during the years 1991-1996. The research was a part of larger high speed technology development research. First, there was the idea of making high speed machinery applications with the Brayton cycle. There was a clear need to deepen the knowledge of the cycle itself and to make a new approach in the field of the research. Also, the removal of water from the humid air seemed very interesting. The goal of this work was to study methods of designing high speed machinery for the reversed Brayton cycle, from theoretical principles to practical applications. The reversed Brayton cycle can be employed as an air dryer, a heat pump or a refrigerating machine. In this research the use of humid air as a working fluid has an environmental advantage, as well. A new calculation method for the Brayton cycle is developed. In this method especially the expansion process in the turbine is important because of the condensation of the water vapour in the humid air. This physical phenomena can have significant effects on the level of performance of the application. Also, the influence of calculating the process with actual, achievable process equipment efficiencies is essential for the development of future machinery. The above theoretical calculations are confirmed with two different laboratory prototypes. (53 refs.)

  12. Direct Numerical Simulation of Disperse Multiphase High-Speed Flows

    Energy Technology Data Exchange (ETDEWEB)

    Nourgaliev, R R; Dinh, T N; Theofanous, T G; Koning, J M; Greenman, R M; Nakafuji, G T

    2004-02-17

    A recently introduced Level-Set-based Cartesian Grid (LSCG) Characteristics-Based Matching (CBM) method is applied for direct numerical simulation of shock-induced dispersal of solid material. The method incorporates the latest advancements in the level set technology and characteristics-based numerical methods for solution of hyperbolic conservation laws and boundary treatment. The LSCG/CBM provides unique capabilities to simulate complex fluid-solid (particulate) multiphase flows under high-speed flow conditions and taking into account particle-particle elastic and viscoelastic collisions. The particular emphasis of the present study is placed on importance of appropriate modeling of particle-particle collisions, which are demonstrated to crucially influence the global behavior of high-speed multiphase particulate flows. The results of computations reveal the richness and complexity of flow structures in compressible disperse systems, due to dynamic formation of shocks and contact discontinuities, which provide an additional long-range interaction mechanism in dispersed high-speed multiphase flows.

  13. Algorithms for High-Speed Noninvasive Eye-Tracking System

    Science.gov (United States)

    Talukder, Ashit; Morookian, John-Michael; Lambert, James

    2010-01-01

    Two image-data-processing algorithms are essential to the successful operation of a system of electronic hardware and software that noninvasively tracks the direction of a person s gaze in real time. The system was described in High-Speed Noninvasive Eye-Tracking System (NPO-30700) NASA Tech Briefs, Vol. 31, No. 8 (August 2007), page 51. To recapitulate from the cited article: Like prior commercial noninvasive eyetracking systems, this system is based on (1) illumination of an eye by a low-power infrared light-emitting diode (LED); (2) acquisition of video images of the pupil, iris, and cornea in the reflected infrared light; (3) digitization of the images; and (4) processing the digital image data to determine the direction of gaze from the centroids of the pupil and cornea in the images. Most of the prior commercial noninvasive eyetracking systems rely on standard video cameras, which operate at frame rates of about 30 Hz. Such systems are limited to slow, full-frame operation. The video camera in the present system includes a charge-coupled-device (CCD) image detector plus electronic circuitry capable of implementing an advanced control scheme that effects readout from a small region of interest (ROI), or subwindow, of the full image. Inasmuch as the image features of interest (the cornea and pupil) typically occupy a small part of the camera frame, this ROI capability can be exploited to determine the direction of gaze at a high frame rate by reading out from the ROI that contains the cornea and pupil (but not from the rest of the image) repeatedly. One of the present algorithms exploits the ROI capability. The algorithm takes horizontal row slices and takes advantage of the symmetry of the pupil and cornea circles and of the gray-scale contrasts of the pupil and cornea with respect to other parts of the eye. The algorithm determines which horizontal image slices contain the pupil and cornea, and, on each valid slice, the end coordinates of the pupil and cornea

  14. Dynamic characteristics of priority control system for high-speed on–off digital valve

    Directory of Open Access Journals (Sweden)

    Yishan Zeng

    2015-04-01

    Full Text Available Dynamic characteristics of the priority control system are of great influence to the control effect, response speed, and working stability of the high-speed on–off digital valve. The main focus of this study is on revealing the dynamic properties of the priority control system for a developed high-speed on–off digital valve. In this article, a detailed introduction to the high-speed on–off digital valve and its priority control system is performed first, which includes the system function, structural composition, and operation principle. Thereafter, a simulation model of the priority control system is established using the AMESim software and the dynamic characteristics are simulated. Simulation results including the variations in the pulse-width modulation signal, coil current, and the main spool displacement of the directional valve are presented and discussed. They indicate that the opening time of the main spool increases with the duty ratio of the voltage signal. Moreover, the main spool displacement is basically equal in one single pulse-width modulation signal cycle, and thus, it is proportional to the cycle number of the pulse-width modulation signal. As a consequence, the priority control system possesses a good dynamic characteristic for the high-speed on–off digital valve as a pilot valve to achieve proportional control of main spool displacement for the directional valve.

  15. Development of High-speed Machining Database with Case-based Reasoning

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Applying high-speed machining technology in shop floor has many benefits, such as manufacturing more accurate parts with better surface finishes. The selection of the appropriate machining parameters plays a very important role in the implementation of high-speed machining technology. The case-based reasoning is used in the developing of high-speed machining database to overcome the shortage of available high-speed cutting parameters in machining data handbooks and shop floors. The high-speed machining data...

  16. Determination of acceleration for belt conveyor speed control in transient operation

    NARCIS (Netherlands)

    He, D.; Pang, Y.; Lodewijks, G.

    2016-01-01

    Speed control has been found a feasible mean to reduce the energy consumption of belt conveyors. However, the current research has not taken the determination of the acceleration in transient operation into account sufficiently. With respect to the belt tension rating, demanded safety factor and the

  17. Numerical analysis of dipole sound source around high speed trains.

    Science.gov (United States)

    Takaishi, Takehisa; Sagawa, Akio; Nagakura, Kiyoshi; Maeda, Tatsuo

    2002-06-01

    As the maximum speed of high speed trains increases, the effect of aeroacoustic noise on the sound level on the ground becomes increasingly important. In this paper, the distribution of dipole sound sources at the bogie section of high speed trains is predicted numerically. The three-dimensional unsteady flow around a train is solved by the large eddy simulation technique. The time history of vortices shows that unstable shear layer separation at the leading edge of the bogie section sheds vortices periodically. These vortices travel downstream while growing to finally impinge upon the trailing edge of the section. The wavelength of sound produced by these vortices is large compared to the representative length of the bogie section, so that the source region can be regarded as acoustically compact. Thus a compact Green's function adapted to the shape can be used to determine the sound. By coupling the instantaneous flow properties with the compact Green's function, the distribution of dipole sources is obtained. The results reveal a strong dipole source at the trailing edge of the bogie section where the shape changes greatly and the variation of flow with time is also great. On the other hand, the bottom of the bogie section where the shape does not change, or the leading edge and boundary layer where the variation of flow with time is small, cannot generate a strong dipole source.

  18. Phoenix: Preliminary design of a high speed civil transport

    Science.gov (United States)

    Aguilar, Joseph; Davis, Steven; Jett, Brian; Ringo, Leslie; Stob, John; Wood, Bill

    1992-01-01

    The goal of the Phoenix Design Project was to develop a second generation high speed civil transport (HSCT) that will meet the needs of the traveler and airline industry beginning in the 21st century. The primary emphasis of the HSCT is to take advantage of the growing needs of the Pacific Basin and the passengers who are involved in that growth. A passenger load of 150 persons, a mission range of 5150 nautical miles, and a cruise speed of Mach 2.5 constitutes the primary design points of this HSCT. The design concept is made possible with the use of a well designed double delta wing and four mixed flow engines. Passenger comfort, compatibility with existing airport infrastructure, and cost competitive with current subsonic aircraft make the Phoenix a viable aircraft for the future.

  19. High speed coding for velocity by archerfish retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    Kretschmer Viola

    2012-06-01

    Full Text Available Abstract Background Archerfish show very short behavioural latencies in response to falling prey. This raises the question, which response parameters of retinal ganglion cells to moving stimuli are best suited for fast coding of stimulus speed and direction. Results We compared stimulus reconstruction quality based on the ganglion cell response parameters latency, first interspike interval, and rate. For stimulus reconstruction of moving stimuli using latency was superior to using the other stimulus parameters. This was true for absolute latency, with respect to stimulus onset, as well as for relative latency, with respect to population response onset. Iteratively increasing the number of cells used for reconstruction decreased the calculated error close to zero. Conclusions Latency is the fastest response parameter available to the brain. Therefore, latency coding is best suited for high speed coding of moving objects. The quantitative data of this study are in good accordance with previously published behavioural response latencies.

  20. Analog parallel processor hardware for high speed pattern recognition

    Science.gov (United States)

    Daud, T.; Tawel, R.; Langenbacher, H.; Eberhardt, S. P.; Thakoor, A. P.

    1990-01-01

    A VLSI-based analog processor for fully parallel, associative, high-speed pattern matching is reported. The processor consists of two main components: an analog memory matrix for storage of a library of patterns, and a winner-take-all (WTA) circuit for selection of the stored pattern that best matches an input pattern. An inner product is generated between the input vector and each of the stored memories. The resulting values are applied to a WTA network for determination of the closest match. Patterns with up to 22 percent overlap are successfully classified with a WTA settling time of less than 10 microsec. Applications such as star pattern recognition and mineral classification with bounded overlap patterns have been successfully demonstrated. This architecture has a potential for an overall pattern matching speed in excess of 10 exp 9 bits per second for a large memory.

  1. High speed cutting of AZ31 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Liwei Lu

    2016-06-01

    Full Text Available Using LBR-370 numerical control lathe, high speed cutting was applied to AZ31 magnesium alloy. The influence of cutting parameters on microstructure, surface roughness and machining hardening were investigated by using the methods of single factor and orthogonal experiment. The results show that the cutting parameters have an important effect on microstructure, surface roughness and machine hardening. The depth of stress layer, roughness and hardening present a declining tendency with the increase of the cutting speed and also increase with the augment of the cutting depth and feed rate. Moreover, we established a prediction model of the roughness, which has an important guidance on actual machining process of magnesium alloy.

  2. Adaptations to speed endurance training in highly trained soccer players

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders

    2016-01-01

    PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects......-Yo Intermittent Recovery Test level 1 (YYIRT-1) was performed and a muscle biopsy was obtained at rest. RESULTS: YYIRT-1 performance was 11.6±6.4% (mean±SD) better (2803±330 vs. 3127±383 m, P

  3. High Speed Gear Sized and Configured to Reduce Windage Loss

    Science.gov (United States)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)

    2013-01-01

    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  4. Mid- to high-frequency noise from high-speed boats and its potential impacts on humpback dolphins.

    Science.gov (United States)

    Li, Songhai; Wu, Haiping; Xu, Youhou; Peng, Chongwei; Fang, Liang; Lin, Mingli; Xing, Luru; Zhang, Peijun

    2015-08-01

    The impact of noise made by vessels on marine animals has come under increased concern. However, most measurements on noise from vessels have only taken into account the low-frequency components. For cetaceans operating in the mid- and high-frequencies, such as the Indo-Pacific humpback dolphin (Sousa chinensis), mid- to high-frequency noise components may be of more concern, in terms of their potential impacts. In this study, noise made by a small high-speed boat was recorded using a broadband recording system in a dolphin watching area focusing on the effects on humpback dolphins in Sanniang Bay, China. The high-speed boat produced substantial mid- to high-frequency noise components with frequencies to >100 kHz, measured at three speeds: ∼40, 30, and 15 km/h. The noise from the boat raised the ambient noise levels from ∼5 to 47 decibels (dB) root-mean-square (rms) across frequency bands ranging from 1 to 125 kHz at a distance of 20 to 85 m, with louder levels recorded at higher speeds and at closer distances. To conclude, the noise produced by the small high-speed boat could be heard by Sousa chinensis and therefore potentially had adverse effects on the dolphins.

  5. Implementation of High Speed Distributed Data Acquisition System

    Science.gov (United States)

    Raju, Anju P.; Sekhar, Ambika

    2012-09-01

    This paper introduces a high speed distributed data acquisition system based on a field programmable gate array (FPGA). The aim is to develop a "distributed" data acquisition interface. The development of instruments such as personal computers and engineering workstations based on "standard" platforms is the motivation behind this effort. Using standard platforms as the controlling unit allows independence in hardware from a particular vendor and hardware platform. The distributed approach also has advantages from a functional point of view: acquisition resources become available to multiple instruments; the acquisition front-end can be physically remote from the rest of the instrument. High speed data acquisition system transmits data faster to a remote computer system through Ethernet interface. The data is acquired through 16 analog input channels. The input data commands are multiplexed and digitized and then the data is stored in 1K buffer for each input channel. The main control unit in this design is the 16 bit processor implemented in the FPGA. This 16 bit processor is used to set up and initialize the data source and the Ethernet controller, as well as control the flow of data from the memory element to the NIC. Using this processor we can initialize and control the different configuration registers in the Ethernet controller in a easy manner. Then these data packets are sending to the remote PC through the Ethernet interface. The main advantages of the using FPGA as standard platform are its flexibility, low power consumption, short design duration, fast time to market, programmability and high density. The main advantages of using Ethernet controller AX88796 over others are its non PCI interface, the presence of embedded SRAM where transmit and reception buffers are located and high-performance SRAM-like interface. The paper introduces the implementation of the distributed data acquisition using FPGA by VHDL. The main advantages of this system are high

  6. Signal Conditioning in Process of High Speed Imaging

    Directory of Open Access Journals (Sweden)

    Libor Hargas

    2015-01-01

    Full Text Available The accuracy of cinematic analysis with camera system depends on frame rate of used camera. Specific case of cinematic analysis is in medical research focusing on microscopic objects moving with high frequencies (cilia of respiratory epithelium. The signal acquired by high speed video acquisition system has very amount of data. This paper describes hardware parts, signal condition and software, which is used for image acquiring thru digital camera, intelligent illumination dimming hardware control and ROI statistic creation. All software parts are realized as virtual instruments.

  7. High-speed optical links for UAV applications

    Science.gov (United States)

    Chen, C.; Grier, A.; Malfa, M.; Booen, E.; Harding, H.; Xia, C.; Hunwardsen, M.; Demers, J.; Kudinov, K.; Mak, G.; Smith, B.; Sahasrabudhe, A.; Patawaran, F.; Wang, T.; Wang, A.; Zhao, C.; Leang, D.; Gin, J.; Lewis, M.; Nguyen, D.; Quirk, K.

    2017-02-01

    High speed optical backbone links between a fleet of UAVs is an integral part of the Facebook connectivity architecture. To support the architecture, the optical terminals need to provide high throughput rates (in excess of tens of Gbps) while achieving low weight and power consumption. The initial effort is to develop and demonstrate an optical terminal capable of meeting the data rate requirements and demonstrate its functions for both air-air and air-ground engagements. This paper is a summary of the effort to date.

  8. Development of FPGA-based High-Speed serial links for High Energy Physics Experiments

    OpenAIRE

    Perrella, Sabrina

    2016-01-01

    High Energy Physics (HEP) experiments generate high volumes of data which need to be transferred over long distance. Then, for data read out, reliable and high-speed links are necessary. Over the years, due to their extreme high bandwidth, serial links (especially optical) have been preferred over the parallel ones. So that, now, high-speed serial links are commonly used in Trigger and Data Acquisition (TDAQ) systems of HEP experiments, not only for data transfer, but also for the distributio...

  9. Investigation of high-speed shaft bearing loads in wind turbine gearboxes through dynamometer testing

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y. [National Wind Technology Center, National Renewable Energy Laboratory, Golden Colorado USA; Keller, J. [National Wind Technology Center, National Renewable Energy Laboratory, Golden Colorado USA

    2017-11-10

    Many wind turbine gearboxes require repair or replacement well before reaching the end of their design life. The most common failure is bearing axial cracks, commonly called white etching cracks (WECs), which typically occur in the inner raceways of the high-speed parallel-stage rolling element bearings. Although the root causes of WECs are debated, one theory is that they are related to routine dynamic operating conditions and occasional transient events prevalent in wind turbines that can result in high bearing stress and sliding of the rolling elements. This paper examined wind turbine gearbox high-speed shaft bearing loads and stresses through modeling and full-scale dynamometer testing. Bearing outer race loads were directly measured and predicted using a variety of modeling tools in normal operations, misaligned conditions, and transient events particularly prone to bearing sliding. Test data and models of bearing loads were well correlated. Neither operational misalignment due to rotor moments nor static generator misalignment affected the bearing loads when compared with pure-torque conditions. Thus, it is not likely that generator misalignment is a causal factor of WECs. In contrast, during transient events, the bearings experienced alternating periods of high stress, torque reversals, and loads under the minimum requisite at high rotating speeds while showing indications of sliding, all of which could be related to the formation of WECs.

  10. Design of an Experimental Setup for Testing Multiphysical Effects on High Speed Mini Rotors

    NARCIS (Netherlands)

    Dikmen, E.; van der Hoogt, Peter; de Boer, Andries; Aarts, Ronald G.K.M.; Jonker, Jan B.

    2011-01-01

    Recently, there have been numerous research projects on the development of minirotating machines. These machines mostly operate at speeds above the first critical speed and have special levitation systems. Besides, the multiphysical effects become significant in small scale. Therefore, advanced

  11. AC_ICAP: A Flexible High Speed ICAP Controller

    Directory of Open Access Journals (Sweden)

    Luis Andres Cardona

    2015-01-01

    Full Text Available The Internal Configuration Access Port (ICAP is the core component of any dynamic partial reconfigurable system implemented in Xilinx SRAM-based Field Programmable Gate Arrays (FPGAs. We developed a new high speed ICAP controller, named AC_ICAP, completely implemented in hardware. In addition to similar solutions to accelerate the management of partial bitstreams and frames, AC_ICAP also supports run-time reconfiguration of LUTs without requiring precomputed partial bitstreams. This last characteristic was possible by performing reverse engineering on the bitstream. Besides, we adapted this hardware-based solution to provide IP cores accessible from the MicroBlaze processor. To this end, the controller was extended and three versions were implemented to evaluate its performance when connected to Peripheral Local Bus (PLB, Fast Simplex Link (FSL, and AXI interfaces of the processor. In consequence, the controller can exploit the flexibility that the processor offers but taking advantage of the hardware speed-up. It was implemented in both Virtex-5 and Kintex7 FPGAs. Results of reconfiguration time showed that run-time reconfiguration of single LUTs in Virtex-5 devices was performed in less than 5 μs which implies a speed-up of more than 380x compared to the Xilinx XPS_HWICAP controller.

  12. High Performance Variable Speed Drive System and Generating System with Doubly Fed Machines

    Science.gov (United States)

    Tang, Yifan

    Doubly fed machines are another alternative for variable speed drive systems. The doubly fed machines, including doubly fed induction machine, self-cascaded induction machine and doubly excited brushless reluctance machine, have several attractive advantages for variable speed drive applications, the most important one being the significant cost reduction with a reduced power converter rating. With a better understanding, improved machine design, flexible power converters and innovated controllers, the doubly fed machines could favorably compete for many applications, which may also include variable speed power generations. The goal of this research is to enhance the attractiveness of the doubly fed machines for both variable speed drive and variable speed generator applications. Recognizing that wind power is one of the favorable clean, renewable energy sources that can contribute to the solution to the energy and environment dilemma, a novel variable-speed constant-frequency wind power generating system is proposed. By variable speed operation, energy capturing capability of the wind turbine is improved. The improvement can be further enhanced by effectively utilizing the doubly excited brushless reluctance machine in slip power recovery configuration. For the doubly fed machines, a stator flux two -axis dynamic model is established, based on which a flexible active and reactive power control strategy can be developed. High performance operation of the drive and generating systems is obtained through advanced control methods, including stator field orientation control, fuzzy logic control and adaptive fuzzy control. System studies are pursued through unified modeling, computer simulation, stability analysis and power flow analysis of the complete drive system or generating system with the machine, the converter and the control. Laboratory implementations and tested results with a digital signal processor system are also presented.

  13. Substructure method in high-speed monorail dynamic problems

    Science.gov (United States)

    Ivanchenko, I. I.

    2008-12-01

    The study of actions of high-speed moving loads on bridges and elevated tracks remains a topical problem for transport. In the present study, we propose a new method for moving load analysis of elevated tracks (monorail structures or bridges), which permits studying the interaction between two strained objects consisting of rod systems and rigid bodies with viscoelastic links; one of these objects is the moving load (monorail rolling stock), and the other is the carrying structure (monorail elevated track or bridge). The methods for moving load analysis of structures were developed in numerous papers [1-15]. At the first stage, when solving the problem about a beam under the action of the simplest moving load such as a moving weight, two fundamental methods can be used; the same methods are realized for other structures and loads. The first method is based on the use of a generalized coordinate in the expansion of the deflection in the natural shapes of the beam, and the problem is reduced to solving a system of ordinary differential equations with variable coefficients [1-3]. In the second method, after the "beam-weight" system is decomposed, just as in the problem with the weight impact on the beam [4], solving the problem is reduced to solving an integral equation for the dynamic weight reaction [6, 7]. In [1-3], an increase in the number of retained forms leads to an increase in the order of the system of equations; in [6, 7], difficulties arise when solving the integral equations related to the conditional stability of the step procedures. The method proposed in [9, 14] for beams and rod systems combines the above approaches and eliminates their drawbacks, because it permits retaining any necessary number of shapes in the deflection expansion and has a resolving system of equations with an unconditionally stable integration scheme and with a minimum number of unknowns, just as in the method of integral equations [6, 7]. This method is further developed for

  14. How sand grains stop a high speed intruder

    Science.gov (United States)

    Behringer, Robert

    When a speeding intruder impacts on a granular material, it comes rapidly to rest after penetrating only a modest distance. Empirical dynamical models, dating to the 19th century (if not earlier), describe the drag on the intruder in terms of two types of depth-dependent forces: one a static force, which also includes gravity, and the other a collisional force proportional to the square of the instantaneous speed of the intruder. What processes occur in the material to so quickly decelerate the intruder? We address this question through experiments and simulations (work of Lou Kondic and collaborators). We first probe the granular response using quasi-two-dimensional granular materials consisting of photoelastic discs. When such a particle experiences a force, it appears bright under cross-polarized illumination. High speed video reveals dynamic force transmission into the material along force chains that form in response to the intruder motion. These chains are nearly normal to the intruder surface, implying that collisional rather than frictional forces dominate the momentum transfer from intruder to grains. These observations allow the formation of a collision-based model that correctly captures the collisional drag force for both 2D and 3D intruders of a variety of shapes. This talk will develop a collisional picture of impact, and also explore the change in the system response as the impact speed increases. Experimental collaborators include Abe Clark, Cacey Stevens Bester, and Alec Petersen. This work supported by DTRA, NSF Grant DMR1206351, NASA Grant NNX15AD38G, and the William M. Keck Foundation.

  15. High-Speed Superconductive Decimation Filter for Sigma-Delta Analog to Digital Converter

    Science.gov (United States)

    Wakamatsu, Tomu; Yamanashi, Yuki; Yoshikawa, Nobuyuki

    2017-07-01

    A superconducting decimation filter is required to convert high-speed output data from a superconducting sigma-delta analog to digital (A/D) modulator to low-speed data for data acquisition by room-temperature electronics. Because the operating frequency of the conventional superconducting decimation filter is lower than that of the maximum operation frequency of A/D modulator, the system performance of the superconducting A/D converter is limited by the decimation filter. We propose a decimation filter that can operate at the sampling frequency of the A/D modulator by hybridizing a shift-register-based and a counter-based decimation filters. The investigated decimation filter can be implemented with a practical circuit area. We designed and tested the investigated decimation filter. The simulation result indicates that the maximum operation frequency of the designed decimation filter is 39.8 GHz assuming the 2.5 kA/cm2 Nb fabrication process. We experimentally confirmed the low-speed operation of the designed decimation filter with the bias margin of 93.8%-110.8%.

  16. Field measurements and analyses of environmental vibrations induced by high-speed Maglev.

    Science.gov (United States)

    Li, Guo-Qiang; Wang, Zhi-Lu; Chen, Suwen; Xu, You-Lin

    2016-10-15

    Maglev, offers competitive journey-times compared to the railway and subway systems in markets for which distance between the stations is 100-1600km owing to its high acceleration and speed; however, such systems may have excessive vibration. Field measurements of Maglev train-induced vibrations were therefore performed on the world's first commercial Maglev line in Shanghai, China. Seven test sections along the line were selected according to the operating conditions, covering speeds from 150 to 430km/h. Acceleration responses of bridge pier and nearby ground were measured in three directions and analyzed in both the time and frequency domain. The effects of Maglev train speed on vibrations of the bridge pier and ground were studied in terms of their peak accelerations. Attenuation of ground vibration was investigated up to 30m from the track centerline. Effects of guideway configuration were also analyzed based on the measurements through two different test sections with same train speed of 300km/h. The results showed that peak accelerations exhibited a strong correlation with both train speed and distance off the track. Guideway configuration had a significant effect on transverse vibration, but a weak impact on vertical and longitudinal vibrations of both bridge pier and ground. Statistics indicated that, contrary to the commonly accepted theory and experience, vertical vibration is not always dominant: transverse and longitudinal vibrations should also be considered, particularly near turns in the track. Moreover, measurements of ground vibration induced by traditional high-speed railway train were carried out with the same testing devices in Bengbu in the Anhui Province. Results showed that the Maglev train generates significantly different vibration signatures as compared to the traditional high-speed train. The results obtained from this paper can provide good insights on the impact of Maglev system on the urban environment and the quality of human life

  17. High-speed two-dimensional laser scanner based on Bragg gratings stored in photothermorefractive glass.

    Science.gov (United States)

    Yaqoob, Zahid; Arain, Muzammil A; Riza, Nabeel A

    2003-09-10

    A high-speed free-space wavelength-multiplexed optical scanner with high-speed wavelength selection coupled with narrowband volume Bragg gratings stored in photothermorefractive (PTR) glass is reported. The proposed scanner with no moving parts has a modular design with a wide angular scan range, accurate beam pointing, low scanner insertion loss, and two-dimensional beam scan capabilities. We present a complete analysis and design procedure for storing multiple tilted Bragg-grating structures in a single PTR glass volume (for normal incidence) in an optimal fashion. Because the scanner design is modular, many PTR glass volumes (each having multiple tilted Bragg-grating structures) can be stacked together, providing an efficient throughput with operations in both the visible and the infrared (IR) regions. A proof-of-concept experimental study is conducted with four Bragg gratings in independent PTR glass plates, and both visible and IR region scanner operations are demonstrated.

  18. Profile parameters of wheelset detection for high speed freight train

    Science.gov (United States)

    Yang, Kai; Ma, Li; Gao, Xiaorong; Wang, Li

    2012-04-01

    Because of freight train, in China, transports goods on railway freight line throughout the country, it does not depart from or return to engine shed during a long phase, thus we cannot monitor the quality of wheel set effectively. This paper provides a system which uses leaser and high speed camera, applies no-contact light section technology to get precise wheel set profile parameters. The paper employs clamping-track method to avoid complex railway ballast modification project. And detailed descript an improved image-tracking algorithm to extract central line from profile curve. For getting one pixel width and continuous line of the profile curve, uses local gray maximum points as direction control points to direct tracking direction. The results based on practical experiment show the system adapted to detection environment of high speed and high vibration, and it can effectively detect the wheelset geometric parameters with high accuracy. The system fills the gaps in wheel set detection for freight train in main line and has an enlightening function on monitoring the quality of wheel set.

  19. Strategy for the Operation of Cooling Towers with variable Speed Fans

    CERN Document Server

    Iñigo-Golfín, J

    2001-01-01

    Within the SPS Cooling Water Project at CERN aimed at the reduction of water consumption, this primary open cooling loop will be closed and all the primary cooling circuit components will be upgraded to the new required duty and brought to the necessary safety and operability standards. In particular the tower fans will be fitted with variable frequency drives to replace the existing two speed motors. This paper presents a study to optimize the operation of SPS cooling towers taking into account outdoor conditions (wet and dry bulb temperatures) and the entirety of the primary circuit in which they will operate.

  20. High-speed signal processing using highly nonlinear optical fibres

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen

    2009-01-01

    We review recent progress in all-optical signal processing techniques making use of conventional silica-based highly nonlinear fibres. In particular, we focus on recent demonstrations of ultra-fast processing at 640 Gbit/s and above, as well as on signal processing of novel modulation formats...... relying on the phase of the optical field. Topics covered include all-optical switching of 640 Gbit/s and 1.28 Tbit/s serial data, wavelength conversion at 640 Gbit/s, optical amplitude regeneration of differential phase shift keying (DPSK) signals, as well as midspan spectral inversion for differential 8......-state phase shift keying (D8PSK) signals....

  1. Deutsche Bahn's new high-speed multiple units

    Energy Technology Data Exchange (ETDEWEB)

    Panier, Frank [Deutsche Bahn, Muenchen (Germany). Engineering and Purchasing Dept.

    2011-03-15

    Given the strong growth in international high-speed passenger business. Deutsche Bahn has decided to expand its relatively small fleet of four-voltage ICE 3s (class 406). The new ICE 3s are to be known as the class 407 and, in addition to operating on Deutsche Bahn's own network as well as in northern und eastern France and in Belgium, it is intended to have them running for the first time in southern France too. (orig.)

  2. Exploring THz band for high speed wireless communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhang, Hangkai; Jia, Shi

    2016-01-01

    We overview recent trend in developing high speed wireless communication systems by exploring large bandwidth available in the THz band, and we also present our recent experimental achievements on 400 GHz wireless transmission with a data rate of up to 60 Gbit/s by using a uni-travelling carrier...... photodiode (UTC-PD) as emitter and a Schottky diode as receiver. This system is foreseen to be capable of accommodating faster data rates beyond 100 Gbit/s, and would find application in bandwidth hungry scenarios....

  3. An adaptive finite element method for high speed flows

    Science.gov (United States)

    Peraire, J.; Morgan, K.; Peiro, J.; Zienkiewicz, O. C.

    1987-01-01

    The solution of the equations of compressible high speed flow, on unstructured triangular grids in 2D and tetrahedral grids in 3D, is considered. Solution methods based upon both Taylor-Galerkin and Runge-Kutta time-stepping techniques are presented and the incorporation of the ideas of flux corrected transport (FCT) is discussed. These methods are combined with an adaptive mesh regeneration procedure and are employed in the solution of several examples, consisting of Euler flows in both 2D and 3D and Navier-Stokes flows in 2D.

  4. 3D high-speed cinematography and its problems

    Science.gov (United States)

    Eisfeld, Fritz

    1999-06-01

    Many fast events are three dimensional but the normal high- speed cameras are only suitable for 2-D images. Therefore it was investigated which stereoscopic methods could be used to study three dimensional processes. The choice of the optimal method is dependent on the investigated event. To record the 3-D spreading of an injection jet in a laboratory has to use other methods as to record an explosion from a smoke bomb in open air. Three methods are described and critically compared. Furthermore it is shown how from films with double pictures a cinematographic film can be made.

  5. High-Speed EMU TCMS Design and LCC Technology Research

    Directory of Open Access Journals (Sweden)

    Hongwei Zhao

    2017-02-01

    Full Text Available This paper introduces the high-speed electrical multiple unit (EMU life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system (TCMS software development platform, the TCMS testing and verification bench, the EMU driving simulation platform, and the EMU remote data transmittal and maintenance platform. All these platforms and benches combined together make up the EMU life cycle cost (LCC system. Each platform facilitates EMU LCC management and is an important part of the system.

  6. Pushbroom Stereo for High-Speed Navigation in Cluttered Environments

    OpenAIRE

    Barry, Andrew J.; Tedrake, Russ

    2014-01-01

    We present a novel stereo vision algorithm that is capable of obstacle detection on a mobile ARM processor at 120 frames per second. Our system performs a subset of standard block-matching stereo processing, searching only for obstacles at a single depth. By using an onboard IMU and state-estimator, we can recover the position of obstacles at all other depths, building and updating a local depth-map at framerate. Here, we describe both the algorithm and our implementation on a high-speed, sma...

  7. Photonic Technologies for Ultra-High-Speed Information Highways

    DEFF Research Database (Denmark)

    Bouchoule, S; Lèfevre, R.; Legros, E.

    1999-01-01

    The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbeds....... This paper reviews the current status of 40 Gbit/s TDM components and subsystem technologies achieved in HIGHWAY. The results of HIGHWAY 40 Gbit/s TDM systems and field tests will be reported in a subsequent paper. (C) 1999 Academic Press....

  8. Preliminary results from the High Speed Airframe Integration Research project

    Science.gov (United States)

    Coen, Peter G.; Sobieszczanski-Sobieski, Jaroslaw; Dollyhigh, Samuel M.

    1992-01-01

    A review is presented of the accomplishment of the near term objectives of developing an analysis system and optimization methods during the first year of the NASA Langley High Speed Airframe Integration Research (HiSAIR) project. The characteristics of a Mach 3 HSCT transport have been analyzed utilizing the newly developed process. In addition to showing more detailed information about the aerodynamic and structural coupling for this type of vehicle, this exercise aided in further refining the data requirements for the analysis process.

  9. A quick-retrieval high-speed digital framing camera

    OpenAIRE

    Sato, A.H.; Yee, J; Bellan, P. M.

    1993-01-01

    A new high-speed digital framing camera is described. The design is built around a rotating polygon mirror that provides a framing rate of 24 000 frames/s. The camera electronics digitizes an image into a 32×104 grid of pixels, where the second dimension of the grid can be varied and is determined by the 8 bit computer-aided measurement and control digitizer sampling rate. Available digitizer memory provides for 314 frames at this horizontal resolution. The advantages over other available hig...

  10. High-speed digital-to-analog converter concepts

    Science.gov (United States)

    Schmidt, Christian; Kottke, Christoph; Jungnickel, Volker; Freund, Ronald

    2017-01-01

    In today's fiber-optic communication systems, the bandwidth of the photonic components, i.e. modulators and photo diodes, is way greater than that of their electrical counterparts, i.e. digital-to-analog converters (DACs) and analog-to-digital converters (ADCs). In order to increase the transmission capacity, the bandwidth limitations need to be overcome. We review the progress and the recent results in the field of high-speed DACs, which are desirable for software-defined transmitters. Furthermore, we evaluate interleaving concepts regarding their ability to overcome the above mentioned limitations and demonstrate recent experimental results for a bandwidth interleaved DAC with 40 GHz analog electrical bandwidth.

  11. High Speed Capacitor-Inverter Based Carbon Nanotube Full Adder

    Directory of Open Access Journals (Sweden)

    Rashtian M

    2010-01-01

    Full Text Available Abstract Carbon Nanotube filed-effect transistor (CNFET is one of the promising alternatives to the MOS transistors. The geometry-dependent threshold voltage is one of the CNFET characteristics, which is used in the proposed Full Adder cell. In this paper, we present a high speed Full Adder cell using CNFETs based on majority-not (Minority function. Presented design uses eight transistors and eight capacitors. Simulation results show significant improvement in terms of delay and power-delay product in comparison to contemporary CNFET Adder Cells. Simulations were carried out using HSPICE based on CNFET model with 0.6 V VDD.

  12. A current review of high speed railways experiences in Asia and Europe

    Science.gov (United States)

    Purba, Aleksander; Nakamura, Fumihiko; Dwsbu, Chatarina Niken; Jafri, Muhammad; Pratomo, Priyo

    2017-11-01

    High-Speed Railways (HSR) is currently regarded as one of the most significant technological breakthroughs in passenger transportation developed in the second half of the 20th century. At the beginning of 2008, there were about 10,000 kilometers of new high-speed lines in operation in Asia and Europe regions to provide high-speed services to passengers willing to pay for lower travel time and quality improvement in rail transport. And since 2010, HSR itself has received a great deal of attention in Indonesia. Some transportation analysts contend that Indonesia, particularly Java and Sumatera islands need a high-speed rail network to be economically competitive with countries in Asia and Europe. On April 2016, Indonesia-China consortium Kereta Cepat Indonesia China (KCIC) signed an engineering, procurement, and construction contract to build the HSR with a consortium of seven companies called the High-Speed Railway Contractor Consortium. The HSR is expected to debut by May 2019, offering a 45-minute trip covering a roughly 150 km route. However, building, maintaining and operating HSR line is expensive; it involves a significant amount of sunk costs and may substantially compromise both the transport policy of a country and the development of its transport sector for decades. The main objective of this paper is to discuss some characteristics of the HSR services from an economic viewpoint, while simultaneously developing an empirical framework that should help us to understand, in more detail, the factors determining the success of the HSR as transport alternative based on current experiences of selected Asian and European countries.

  13. Ultra-High-Speed Image Signal Accumulation Sensor

    Directory of Open Access Journals (Sweden)

    Takeharu Goji Etoh

    2010-04-01

    Full Text Available Averaging of accumulated data is a standard technique applied to processing data with low signal-to-noise ratios (SNR, such as image signals captured in ultra-high-speed imaging. The authors propose an architecture layout of an ultra-high-speed image sensor capable of on-chip signal accumulation. The very high frame rate is enabled by employing an image sensor structure with a multi-folded CCD in each pixel, which serves as an in situ image signal storage. The signal accumulation function is achieved by direct connection of the first and the last storage elements of the in situ storage CCD. It has been thought that the multi-folding is achievable only by driving electrodes with complicated and impractical layouts. Simple configurations of the driving electrodes to overcome the difficulty are presented for two-phase and four-phase transfer CCD systems. The in situ storage image sensor with the signal accumulation function is named Image Signal Accumulation Sensor (ISAS.

  14. Storage and compression design of high speed CCD

    Science.gov (United States)

    Cai, Xichang; Zhai, LinPei

    2009-05-01

    In current field of CCD measurement, large area and high resolution CCD is used to obtain big measurement image, so that, speed and capacity of CCD requires high performance of later storage and process system. The paper discusses how to use SCSI hard disk to construct storage system and use DSPs and FPGA to realize image compression. As for storage subsystem, Because CCD is divided into multiplex output, SCSI array is used in RAID0 way. The storage system is com posed of high speed buffer, DM A controller, control M CU, SCSI protocol controller and SCSI hard disk. As for compression subsystem, according to requirement of communication and monitor system, the output is fixed resolution image and analog PA L signal. The compression means is JPEG 2000 standard, in which, 9/7 wavelets in lifting format is used. 2 DSPs and FPGA are used to com pose parallel compression system. The system is com posed of FPGA pre-processing module, DSP compression module, video decoder module, data buffer module and communication module. Firstly, discrete wavelet transform and quantization is realized in FPGA. Secondly, entropy coding and stream adaption is realized in DSPs. Last, analog PA L signal is output by Video decoder. Data buffer is realized in synchronous dual-port RAM and state of subsystem is transfer to controller. Through subjective and objective evaluation, the storage and compression system satisfies the requirement of system.

  15. High speed optical filtering using active resonant subwavelength gratings

    Science.gov (United States)

    Gin, A. V.; Kemme, S. A.; Boye, R. R.; Peters, D. W.; Ihlefeld, J. F.; Briggs, R. D.; Wendt, J. R.; Ellis, A. R.; Marshall, L. H.; Carter, T. R.; Hunker, J. D.; Samora, S.

    2010-02-01

    In this work, we describe the most recent progress towards the device modeling, fabrication, testing and system integration of active resonant subwavelength grating (RSG) devices. Passive RSG devices have been a subject of interest in subwavelength-structured surfaces (SWS) in recent years due to their narrow spectral response and high quality filtering performance. Modulating the bias voltage of interdigitated metal electrodes over an electrooptic thin film material enables the RSG components to act as actively tunable high-speed optical filters. The filter characteristics of the device can be engineered using the geometry of the device grating and underlying materials. Using electron beam lithography and specialized etch techniques, we have fabricated interdigitated metal electrodes on an insulating layer and BaTiO3 thin film on sapphire substrate. With bias voltages of up to 100V, spectral red shifts of several nanometers are measured, as well as significant changes in the reflected and transmitted signal intensities around the 1.55um wavelength. Due to their small size and lack of moving parts, these devices are attractive for high speed spectral sensing applications. We will discuss the most recent device testing results as well as comment on the system integration aspects of this project.

  16. High speed and wide bandwidth delta-sigma ADCs

    CERN Document Server

    Bolatkale, Muhammed; Makinwa, Kofi A A

    2014-01-01

    This book describes techniques for realizing wide bandwidth (125MHz) over-sampled analog-to-digital converters (ADCs) in nanometer-CMOS processes.  The authors offer a clear and complete picture of system level challenges and practical design solutions in high-speed Delta-Sigma modulators.  Readers will be enabled to implement ADCs as continuous-time delta-sigma (CT∆Σ) modulators, offering simple resistive inputs, which do not require the use of power-hungry input buffers, as well as offering inherent anti-aliasing, which simplifies system integration. The authors focus on the design of high speed and wide-bandwidth ΔΣMs that make a step in bandwidth range which was previously only possible with Nyquist converters. More specifically, this book describes the stability, power efficiency, and linearity limits of ΔΣMs, aiming at a GHz sampling frequency.   • Provides overview of trends in Wide Bandwidth and High Dynamic Range analog-to-digital converters (ADCs); • Enables the design of a wide band...

  17. Large area high-speed metrology SPM system

    Science.gov (United States)

    Klapetek, P.; Valtr, M.; Picco, L.; Payton, O. D.; Martinek, J.; Yacoot, A.; Miles, M.

    2015-02-01

    We present a large area high-speed measuring system capable of rapidly generating nanometre resolution scanning probe microscopy data over mm2 regions. The system combines a slow moving but accurate large area XYZ scanner with a very fast but less accurate small area XY scanner. This arrangement enables very large areas to be scanned by stitching together the small, rapidly acquired, images from the fast XY scanner while simultaneously moving the slow XYZ scanner across the region of interest. In order to successfully merge the image sequences together two software approaches for calibrating the data from the fast scanner are described. The first utilizes the low uncertainty interferometric sensors of the XYZ scanner while the second implements a genetic algorithm with multiple parameter fitting during the data merging step of the image stitching process. The basic uncertainty components related to these high-speed measurements are also discussed. Both techniques are shown to successfully enable high-resolution, large area images to be generated at least an order of magnitude faster than with a conventional atomic force microscope.

  18. Role of the eye in high-speed motion analysis

    Science.gov (United States)

    Hyzer, William G.

    1997-05-01

    Prior to the investigation of the photographic process over 150 years ago, the analyses of rapid motions were limited by the dynamic efficacies of the human eye, which has a temporal resolution of approximately 1/10 sec and a maximum information acquisition rate estimated at 103 to 104 bits/sec. At high rates of object motion, only the simplest actions can be resolved, comprehended and retained in human memory. Advances in the field of high-speed photography drastically changed all this by providing us with the ability today to capture permanent images of transient events at acquisition rates in excess of 1012 bits/sec. As remarkable as these improvements in temporal resolution and image retention may be, the final step in correctly interpreting any image still rests largely upon the analyst's ability to process visual data. Those who enter the field of image analysis soon learn how capricious the eye can be in this task. It is incumbent upon anyone performing important image analyses to have at least a basic understanding of the eye's performance characteristics, especially its limitations and capricious anomalies. Exemplary data presented in this paper are drawn from the scientific literature and the author's forty years of experience as a researcher, author and educator in the field of high-speed imaging.

  19. Parametric studies on floating pad journal bearing for high speed cryogenic turboexpanders

    Science.gov (United States)

    Jain, A.; Jadhav, M. M.; Karimulla, S.; Chakravarty, A.

    2017-12-01

    Most modern medium and large capacity helium liquefaction/refrigeration plants employ high speed cryogenic turboexpanders in their refrigeration/liquefaction cycles as active cooling devices. The operating speed of these turboexpanders is in the range of 3000-5000 Hz and hence specialized types of bearings are required. Floating pad journal bearing, which is a special type of tilting pad journal bearing, where mechanical pivots are absent and pads are fully suspended in gas, can be a good solution for stable operation of these high speed compact rotors. The pads are separated from shaft as well as from housing by fluid film between them, and both these sides of pad are interconnected by a network of feed holes. The work presented in this article aims to characterize floating pad journal bearings through parametric studies. The steady state performance characteristics of the bearing are represented by load capacity, stiffness coefficients and heat generation rate of the bearing. The geometrical parameters such as bearing clearances, preload of pads, etc. are varied and performance characteristics of the floating pad journal bearing are studied and presented. The dependence of stiffness coefficients on rotational speed of shaft is also analyzed.

  20. Fault Diagnosis of a High-Speed Cam-Driven Pin Assembly System

    Directory of Open Access Journals (Sweden)

    Chi-Cheng Cheng

    2016-01-01

    Full Text Available A cam-driven mechanical system applied for pin assembly of connectors of electrical devices is studied in this paper. Three cooperative cams are involved in the tasks of approaching, cutting, insertion, and restoring. In order to meet the demanded productivity growth, the operation speed tends to be elevated. However, high running speeds usually cause deficiencies of pin dropping and inaccurate positioning. Diagnosis is therefore conducted to explore their physical reasons so that modification of future mechanical design can be made. Frequency responses of experimental measurements show greater natural frequency and system stiffness caused by nonlinear dynamics for higher operation speed. It also appears that the clamping force is reduced and drift of the locked pin’s location is induced for higher running speed. In addition, separation of the fixture system induced by contact oscillation generates clearance larger than the thickness of the pin. Based on the mathematical models obtained from the technique of system identification, deeper insight of the mechanical system and future system improvement can be highly expected.

  1. Stingray: high-speed control of small UGVs in urban terrain

    Science.gov (United States)

    Yamauchi, Brian; Massey, Kent

    2009-05-01

    For the TARDEC-funded Stingray Project, iRobot Corporation and Chatten Associates are developing technologies that will allow small UGVs to operate at tactically useful speeds. In previous work, we integrated a Chatten Head-Aimed Remote Viewer (HARV) with an iRobot Warrior UGV, and used the HARV to drive the Warrior, as well as a small, high-speed, gas-powered UGV surrogate. In this paper, we describe our continuing work implementing semiautonomous driver-assist behaviors to help an operator control a small UGV at high speeds. We have implemented an IMU-based heading control behavior that enables tracked vehicles to maintain accurate heading control even over rough terrain. We are also developing a low-latency, low-bandwidth, high-quality digital video protocol to support immersive visual telepresence. Our experiments show that a video compression codec using the H.264 algorithm can produce several times better resolution than a Motion JPEG video stream, while utilizing the same limited bandwidth, and the same low latency. With further enhancements, our H.264 codec will provide an order of magnitude greater quality, while retaining a low latency comparable to Motion JPEG, and operating within the same bandwidth.

  2. High-speed 3D imaging using two-wavelength parallel-phase-shift interferometry.

    Science.gov (United States)

    Safrani, Avner; Abdulhalim, Ibrahim

    2015-10-15

    High-speed three dimensional imaging based on two-wavelength parallel-phase-shift interferometry is presented. The technique is demonstrated using a high-resolution polarization-based Linnik interferometer operating with three high-speed phase-masked CCD cameras and two quasi-monochromatic modulated light sources. The two light sources allow for phase unwrapping the single source wrapped phase so that relatively high step profiles having heights as large as 3.7 μm can be imaged in video rate with ±2  nm accuracy and repeatability. The technique is validated using a certified very large scale integration (VLSI) step standard followed by a demonstration from the semiconductor industry showing an integrated chip with 2.75 μm height copper micro pillars at different packing densities.

  3. Material Properties of High-Speed Steel Rolls

    Directory of Open Access Journals (Sweden)

    Shaohua Wu

    2017-03-01

    Full Text Available Recently, it has been required to improve the material properties of high-speed steel (HSS rolls, because of the low wear resistance and low mechanical properties. To improve them, several new steels have been proposed, which have high wear resistance as well as excellent mechanical properties, e.g., hardness and tensile properties, where additional elements (V, Cr and W were employed. However, their steels may have still technical issues, as the roll surfaces become roughened during the production process. The reason for this problem is found to be affected by the oxidation of the HSS surface. In this work, we have provided the suggestions to make high wear resistance of the HSS rolls

  4. Unbalance Response Analysis and Experimental Validation of an Ultra High Speed Motor-Generator for Microturbine Generators Considering Balancing

    Directory of Open Access Journals (Sweden)

    Do-Kwan Hong

    2014-08-01

    Full Text Available The objective of the present study was to deal with the rotordynamics of the rotor of an ultra-high speed PM type synchronous motor-generator for a 500 W rated micro gas turbine generator. This paper introduces dynamic analysis, and experiments on the motor-generator. The focus is placed on an analytical approach considering the mechanical dynamic problems. It is essential to deal with dynamic stability at ultra-high speeds. Unbalance response analysis is performed by calculating the unbalance with and without balancing using a balancing machine. Critical speed analysis is performed to determine the operating speed with sufficient separation margin. The unbalance response analysis is compared with the experimental results considering the balancing grade (ISO 1940-1 and predicted vibration displacement with and without balancing. Based on these results, a high-speed motor-generator was successfully developed.

  5. Unbalance Response Analysis and Experimental Validation of an Ultra High Speed Motor-Generator for Microturbine Generators Considering Balancing

    Science.gov (United States)

    Hong, Do-Kwan; Joo, Dae-Suk; Woo, Byung-Chul; Koo, Dae-Hyun; Ahn, Chan-Woo

    2014-01-01

    The objective of the present study was to deal with the rotordynamics of the rotor of an ultra-high speed PM type synchronous motor-generator for a 500 W rated micro gas turbine generator. This paper introduces dynamic analysis, and experiments on the motor-generator. The focus is placed on an analytical approach considering the mechanical dynamic problems. It is essential to deal with dynamic stability at ultra-high speeds. Unbalance response analysis is performed by calculating the unbalance with and without balancing using a balancing machine. Critical speed analysis is performed to determine the operating speed with sufficient separation margin. The unbalance response analysis is compared with the experimental results considering the balancing grade (ISO 1940-1) and predicted vibration displacement with and without balancing. Based on these results, a high-speed motor-generator was successfully developed. PMID:25177804

  6. Unbalance response analysis and experimental validation of an ultra high speed motor-generator for microturbine generators considering balancing.

    Science.gov (United States)

    Hong, Do-Kwan; Joo, Dae-Suk; Woo, Byung-Chul; Koo, Dae-Hyun; Ahn, Chan-Woo

    2014-08-29

    The objective of the present study was to deal with the rotordynamics of the rotor of an ultra-high speed PM type synchronous motor-generator for a 500 W rated micro gas turbine generator. This paper introduces dynamic analysis, and experiments on the motor-generator. The focus is placed on an analytical approach considering the mechanical dynamic problems. It is essential to deal with dynamic stability at ultra-high speeds. Unbalance response analysis is performed by calculating the unbalance with and without balancing using a balancing machine. Critical speed analysis is performed to determine the operating speed with sufficient separation margin. The unbalance response analysis is compared with the experimental results considering the balancing grade (ISO 1940-1) and predicted vibration displacement with and without balancing. Based on these results, a high-speed motor-generator was successfully developed.

  7. Energy and economic analysis of an ICE-based variable speed-operated micro-cogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Caresana, Flavio; Bartolini, Carlo Maria [Universita Politecnica delle Marche, Dipartimento di Energetica, Via Brecce Bianche, Ancona (AN) 60100 (Italy); Brandoni, Caterina [Universita Telematica e-Campus, Ingegneria Energetica, Via Isimbardi 10, Novedrate (CO) 22060 (Italy); Feliciotti, Petro [Universita Politecnica delle Marche, Dipartimento di Ingegneria Informatica, Gestionale e dell' Automazione, Via Brecce Bianche, Ancona (AN) 60100 (Italy)

    2011-03-15

    Micro-combined heat and power (CHP) systems are a key resource to meet the EUCO{sub 2} reduction agreed in the Kyoto Protocol. In the near future they are likely to spread significantly through applications in the residential and service sectors, since they can provide considerably higher primary energy efficiencies than plants generating electricity and heat separately. A 28 kW{sub e} natural gas, automotive-derived internal combustion engine CHP system was modeled with a view to comparing constant and variable speed operation modes. Besides their energy performances, the paper addresses the major factors involved in their economic evaluation and describes a method to assess their economic feasibility. Typical residential and service sector applications were chosen as test cases and the results discussed in terms of energy performances and of profitability. They showed that interesting savings can be obtained with respect to separate generation, and that they are higher for the household application in variable speed operating conditions. In fact the plant's energy performance is greatly enhanced by the possibility, for any given power, to regulate the engine's rotational speed. From the economic viewpoint, despite the higher initial cost of the variable speed concept, the system involves a shorter pay-back period and ensures greater profit. (author)

  8. Design of Stirrer Impeller with Variable Operational Speed for a Food Waste Homogenizer

    Directory of Open Access Journals (Sweden)

    Idris A. Kayode

    2016-05-01

    Full Text Available A conceptualized impeller called KIA is designed for impact agitation of food waste in a homogenizer. A comparative analysis of the performance of KIA is made with three conventional impeller types, Rushton, Anchor, and Pitched Blade. Solid–liquid mixing of a moisture-rich food waste is simulated under various operational speeds, in order to compare the dispersions and thermal distributions at homogenous slurry conditions. Using SolidWorks, the design of the impellers employs an Application Programming Interface (API which acts as the canvas for creating a graphical user interface (GUI for automation of its assembly. A parametric analysis of the homogenizer, at varying operational speeds, enables the estimation of the critical speed of the mixing shaft diameter and the deflection under numerous mixing conditions and impeller configurations. The numerical simulation of the moisture-rich food waste (approximated as a Newtonian carrot–orange soup is performed with ANSYS CFX v.15.0. The velocity and temperature field distribution of the homogenizer for various impeller rotational speeds are analyzed. It is anticipated that the developed model will help in the selection of a suitable impeller for efficient mixing of food waste in the homogenizer.

  9. Dark matter phenomenology of high-speed galaxy cluster collisions

    Energy Technology Data Exchange (ETDEWEB)

    Mishchenko, Yuriy [Izmir University of Economics, Faculty of Engineering, Izmir (Turkey); Ji, Chueng-Ryong [North Carolina State University, Department of Physics, Raleigh, NC (United States)

    2017-08-15

    We perform a general computational analysis of possible post-collision mass distributions in high-speed galaxy cluster collisions in the presence of self-interacting dark matter. Using this analysis, we show that astrophysically weakly self-interacting dark matter can impart subtle yet measurable features in the mass distributions of colliding galaxy clusters even without significant disruptions to the dark matter halos of the colliding galaxy clusters themselves. Most profound such evidence is found to reside in the tails of dark matter halos' distributions, in the space between the colliding galaxy clusters. Such features appear in our simulations as shells of scattered dark matter expanding in alignment with the outgoing original galaxy clusters, contributing significant densities to projected mass distributions at large distances from collision centers and large scattering angles of up to 90 {sup circle}. Our simulations indicate that as much as 20% of the total collision's mass may be deposited into such structures without noticeable disruptions to the main galaxy clusters. Such structures at large scattering angles are forbidden in purely gravitational high-speed galaxy cluster collisions. Convincing identification of such structures in real colliding galaxy clusters would be a clear indication of the self-interacting nature of dark matter. Our findings may offer an explanation for the ring-like dark matter feature recently identified in the long-range reconstructions of the mass distribution of the colliding galaxy cluster CL0024+017. (orig.)

  10. Control-Surface Instability on High-Speed Airplanes

    Science.gov (United States)

    Phillips, William H.

    1942-01-01

    Tests of several modern airplanes indicate that control surfaces with a high degree of aerodynamic balance are likely to possess characteristics which make them unsatisfactory or dangerous in high-speed flight. Dive tests made in the spring of 1940 at the NACA on a naval fighter-type airplane illustrate one form of instability that may be encountered. During a dive at an indicated airspeed of 365 miles per hour, the ailerons suddenly overbalanced. The efforts of the pilot to bring the ailerons back to neutral resulted in a violent oscillation of the control stick from side to side. Fortunately, the force required to return the ailerons to neutral was within the pilot's capabilities. A time history of the maneuver is given in figure1 and typical frames from motion pictures of the cockpit and of the wing, taken during the maneuver, are given in figure 2. In the illustrated case, the occurrence of aerodynamic overbalance was attributed to a slight bulge, approximately 1/16 inch thick, on the lower surface of the leading edges of the ailerons, caused by the installation of additional mass balance ahead of the hinge line. A drawing showing the shape of the bulge is given in figure 3. After this slight protuberance had been eliminated, dives were successfully made at higher speeds.

  11. Preliminary design of nine high speed civil transports

    Science.gov (United States)

    Sandlin, Doral; Vantriet, Robert; Soban, Dani; Hoang, TY

    1992-01-01

    Sixty senior design students at Cal Poly, SLO have completed a year-long project to design the next generation of High Speed Civil Transports (HSCT). The design process was divided up into three distinct phases. The first third of the project was devoted entirely to research into the special problems associated with an HSCT. These included economic viability, airport compatibility, high speed aerodynamics, sonic boom minimization, environmental impact, and structures and materials. The result of this research was the development of nine separate Requests for Proposal (RFP) that outlined reasonable yet challenging design criteria for the aircraft. All were designed to be technically feasible in the year 2015. The next phase of the project divided the sixty students into nine design groups. Each group, with its own RFP, completed a Class 1 preliminary design of an HSCT. The nine configurations varied from conventional double deltas to variable geometry wings to a pivoting oblique wing design. The final phase of the project included a more detailed Class 2 sizing as well as performance and stability and control analysis. Cal Poly, San Luis Obispo presents nine unique solutions to the same problem: that of designing an economically viable, environmentally acceptable, safe and comfortable supersonic transport.

  12. High-speed stimulated Brillouin scattering spectroscopy at 780 nm

    Directory of Open Access Journals (Sweden)

    Itay Remer

    2016-09-01

    Full Text Available We demonstrate a high-speed stimulated Brillouin scattering (SBS spectroscopy system that is able to acquire stimulated Brillouin gain point-spectra in water samples and Intralipid tissue phantoms over 2 GHz within 10 ms and 100 ms, respectively, showing a 10-100 fold increase in acquisition rates over current frequency-domain SBS spectrometers. This improvement was accomplished by integrating an ultra-narrowband hot rubidium-85 vapor notch filter in a simplified frequency-domain SBS spectrometer comprising nearly counter-propagating continuous-wave pump-probe light at 780 nm and conventional single-modulation lock-in detection. The optical notch filter significantly suppressed stray pump light, enabling detection of stimulated Brillouin gain spectra with substantially improved acquisition times at adequate signal-to-noise ratios (∼25 dB in water samples and ∼15 dB in tissue phantoms. These results represent an important step towards the use of SBS spectroscopy for high-speed measurements of Brillouin gain resonances in scattering and non-scattering samples.

  13. High-speed atomic force microscopy: imaging and force spectroscopy.

    Science.gov (United States)

    Eghiaian, Frédéric; Rico, Felix; Colom, Adai; Casuso, Ignacio; Scheuring, Simon

    2014-10-01

    Atomic force microscopy (AFM) is the type of scanning probe microscopy that is probably best adapted for imaging biological samples in physiological conditions with submolecular lateral and vertical resolution. In addition, AFM is a method of choice to study the mechanical unfolding of proteins or for cellular force spectroscopy. In spite of 28 years of successful use in biological sciences, AFM is far from enjoying the same popularity as electron and fluorescence microscopy. The advent of high-speed atomic force microscopy (HS-AFM), about 10 years ago, has provided unprecedented insights into the dynamics of membrane proteins and molecular machines from the single-molecule to the cellular level. HS-AFM imaging at nanometer-resolution and sub-second frame rate may open novel research fields depicting dynamic events at the single bio-molecule level. As such, HS-AFM is complementary to other structural and cellular biology techniques, and hopefully will gain acceptance from researchers from various fields. In this review we describe some of the most recent reports of dynamic bio-molecular imaging by HS-AFM, as well as the advent of high-speed force spectroscopy (HS-FS) for single protein unfolding. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  14. High-speed digital video tracking system for generic applications

    Science.gov (United States)

    Walton, James S.; Hallamasek, Karen G.

    2001-04-01

    The value of high-speed imaging for making subjective assessments is widely recognized, but the inability to acquire useful data from image sequences in a timely fashion has severely limited the use of the technology. 4DVideo has created a foundation for a generic instrument that can capture kinematic data from high-speed images. The new system has been designed to acquire (1) two-dimensional trajectories of points; (2) three-dimensional kinematics of structures or linked rigid-bodies; and (3) morphological reconstructions of boundaries. The system has been designed to work with an unlimited number of cameras configured as nodes in a network, with each camera able to acquire images at 1000 frames per second (fps) or better, with a spatial resolution of 512 X 512 or better, and an 8-bit gray scale. However, less demanding configurations are anticipated. The critical technology is contained in the custom hardware that services the cameras. This hardware optimizes the amount of information stored, and maximizes the available bandwidth. The system identifies targets using an algorithm implemented in hardware. When complete, the system software will provide all of the functionality required to capture and process video data from multiple perspectives. Thereafter it will extract, edit and analyze the motions of finite targets and boundaries.

  15. Quantitative Image Analysis Techniques with High-Speed Schlieren Photography

    Science.gov (United States)

    Pollard, Victoria J.; Herron, Andrew J.

    2017-01-01

    Optical flow visualization techniques such as schlieren and shadowgraph photography are essential to understanding fluid flow when interpreting acquired wind tunnel test data. Output of the standard implementations of these visualization techniques in test facilities are often limited only to qualitative interpretation of the resulting images. Although various quantitative optical techniques have been developed, these techniques often require special equipment or are focused on obtaining very precise and accurate data about the visualized flow. These systems are not practical in small, production wind tunnel test facilities. However, high-speed photography capability has become a common upgrade to many test facilities in order to better capture images of unsteady flow phenomena such as oscillating shocks and flow separation. This paper describes novel techniques utilized by the authors to analyze captured high-speed schlieren and shadowgraph imagery from wind tunnel testing for quantification of observed unsteady flow frequency content. Such techniques have applications in parametric geometry studies and in small facilities where more specialized equipment may not be available.

  16. High-Speed Solar Wind and Geomagnetic Activity

    Science.gov (United States)

    Olyak, M. R.

    2015-03-01

    The impact of high-speed solar wind disturbances on the occurrence of geomagnetic storms is analyzed. The solar wind velocity values, determined from scintillation observations at the UTR-2 and URAN-2 Ukrainian decameter radio telescopes are analyzed together with the solar wind parameters at the Earth’s orbit and geomagnetic indices Ap. The solar wind velocity increase during observations was chiefly caused by the high-speed streams from coronal holes. At the time of February 2011, the X-class solar flare, accompanied by coronal mass ejections, was also observed. It was found that the geomagnetic disturbances of that period occurred at negative daily values of the interplanetary magnetic field component being perpendicular to the ecliptic plane. It was shown that the increasing solar wind velocity observed with the UTR-2 and URAN-2 within a wide range of helio- latitudes leads to increase in geomagnetic index Ap and to geomagnetic disturbance. Whereas the increase of solar wind velocity in a narrow range of helio-latitudes near to the ecliptic plane was never accompanied by geomagnetic perturbations.

  17. High-speed visual feedback for realizing high-performance robotic manipulation

    Science.gov (United States)

    Huang, S.; Bergström, N.; Yamakawa, Y.; Senoo, T.; Ishikawa, M.

    2017-02-01

    High-speed vision sensing becomes a driving factor in developing new methods for robotic manipulation. In this paper we present two such methods in order to realize high-performance manipulation. First, we present a dynamic compensation approach which aims to achieve simultaneously fast and accurate positioning under various (from system to external environment) uncertainties. Second, a high-speed motion strategy for manipulating flexible objects is introduced to address the issue of deformation uncertainties. Both methods rely on high-speed visual feedback and are model independent, which we believe is essential to ensure good flexibility in a wide range of applications. The high-speed visual feedback tracks the relative error between the working tool and the target in image coordinates, which implies that there is no need for accurate calibrations of the vision system. Tasks for validating these methods were implemented and experimental results were provided to illustrate the effectiveness of the proposed methods.

  18. High-speed bridge circuit for InGaAs avalanche photodiode single-photon detector

    Science.gov (United States)

    Hashimoto, Hirofumi; Tomita, Akihisa; Okamoto, Atsushi

    2014-02-01

    Because of low power consumption and small footprint, avalanche photodiodes (APD) have been commonly applied to photon detection. Recently, high speed quantum communication has been demonstrated for high bit-rate quantum key distribution. For the high speed quantum communication, photon detectors should operate at GHz-clock frequencies. We propose balanced detection circuits for GHz-clock operation of InGaAs-APD photon detectors. The balanced single photon detector operates with sinusoidal wave gating. The sinusoidal wave appearing in the output is removed by the subtraction from APD signal without sharp band-elimination filters. Omission of the sharp filters removes the constraint on the operating frequency of the single photon detector. We present two designs, one works with two identical APDs, the other with one APD and a low-pass filter. The sinusoidal gating enables to eliminate the gating noise even with the simple configuration of the latter design. We demonstrated the balanced single photon detector operating with 1.020GHz clock at 233 K, 193 K, and 186.5 K. The dark count probability was 4.0 x 10-4 counts/pulse with the quantum efficiency of 10% at 233K, and 1.6 x 10-4 counts/pulse at 186.5 K. These results were obtained with easily available APDs (NR8300FP-C.C, RENESASS) originally developed for optical time-domain reflectmeters.

  19. Influence of “J”-Curve Spring Stiffness on Running Speeds of Segmented Legs during High-Speed Locomotion

    Directory of Open Access Journals (Sweden)

    Runxiao Wang

    2016-01-01

    Full Text Available Both the linear leg spring model and the two-segment leg model with constant spring stiffness have been broadly used as template models to investigate bouncing gaits for legged robots with compliant legs. In addition to these two models, the other stiffness leg spring models developed using inspiration from biological characteristic have the potential to improve high-speed running capacity of spring-legged robots. In this paper, we investigate the effects of “J”-curve spring stiffness inspired by biological materials on running speeds of segmented legs during high-speed locomotion. Mathematical formulation of the relationship between the virtual leg force and the virtual leg compression is established. When the SLIP model and the two-segment leg model with constant spring stiffness and with “J”-curve spring stiffness have the same dimensionless reference stiffness, the two-segment leg model with “J”-curve spring stiffness reveals that (1 both the largest tolerated range of running speeds and the tolerated maximum running speed are found and (2 at fast running speed from 25 to 40/92 m s−1 both the tolerated range of landing angle and the stability region are the largest. It is suggested that the two-segment leg model with “J”-curve spring stiffness is more advantageous for high-speed running compared with the SLIP model and with constant spring stiffness.

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

    Directory of Open Access Journals (Sweden)

    Urs Giger

    2017-01-01

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

  1. HYDROGEN ADDITION ON COMBUSTION AND EMISSION CHARACTERISTICS OF HIGH SPEED SPARK IGNITION ENGINE- AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    SHIVAPRASAD K. V.

    2016-11-01

    Full Text Available The present article aims at characterizing the combustion and emission parameters of a single cylinder high speed SI engine operating with different concentrations of hydrogen with gasoline fuel. The conventional carburetted SI engine was modified into an electronically controllable engine, wherein ECU was used to control the injection timings and durations of gasoline. The engine was maintained at a constant speed of 3000 rpm and wide open throttle position. The experimental results demonstrated that heat release rate and cylinder pressure were increased with the addition of hydrogen until 20%. The CO and HC emissions were reduced considerably whereas NOx emission was increased with the addition of hydrogen in comparison with pure gasoline engine operation.

  2. Detecting and Blocking Network Attacks at Ultra High Speeds

    Energy Technology Data Exchange (ETDEWEB)

    Paxson, Vern

    2010-11-29

    Stateful, in-depth, in-line traffic analysis for intrusion detection and prevention has grown increasingly more difficult as the data rates of modern networks rise. One point in the design space for high-performance network analysis - pursued by a number of commercial products - is the use of sophisticated custom hardware. For very high-speed processing, such systems often cast the entire analysis process in ASICs. This project pursued a different architectural approach, which we term Shunting. Shunting marries a conceptually quite simple hardware device with an Intrusion Prevention System (IPS) running on commodity PC hardware. The overall design goal is was to keep the hardware both cheap and readily scalable to future higher speeds, yet also retain the unparalleled flexibility that running the main IPS analysis in a full general-computing environment provides. The Shunting architecture we developed uses a simple in-line hardware element that maintains several large state tables indexed by packet header fields, including IP/TCP flags, source and destination IP addresses, and connection tuples. The tables yield decision values the element makes on a packet-by-packet basis: forward the packet, drop it, or divert ('shunt') it through the IPS (the default). By manipulating table entries, the IPS can, on a fine-grained basis: (i) specify the traffic it wishes to examine, (ii) directly block malicious traffic, and (iii) 'cut through' traffic streams once it has had an opportunity to 'vet' them, or (iv) skip over large items within a stream before proceeding to further analyze it. For the Shunting architecture to yield benefits, it needs to operate in an environment for which the monitored network traffic has the property that - after proper vetting - much of it can be safely skipped. This property does not universally hold. For example, if a bank needs to examine all Web traffic involving its servers for regulatory compliance, then a

  3. Demonstration, Testing and Qualification of a High Temperature, High Speed Magnetic Thrust Bearing

    Science.gov (United States)

    DeWitt, Kenneth

    2005-01-01

    The gas turbine industry has a continued interest in improving engine performance and reducing net operating and maintenance costs. These goals are being realized because of advancements in aeroelasticity, materials, and computational tools such as CFD and engine simulations. These advancements aid in increasing engine thrust-to-weight ratios, specific fuel consumption, pressure ratios, and overall reliability through higher speed, higher temperature, and more efficient engine operation. Currently, rolling element bearing and squeeze film dampers are used to support rotors in gas turbine engines. Present ball bearing configurations are limited in speed (bearings require extensive preventative maintenance in order to assure their safe operation. Since these bearings are at their operational limits, new technologies must be found in order to take advantage of other advances. Magnetic bearings are well suited to operate at extreme temperatures and higher rotational speeds and are a promising solution to the problems that conventional rolling element bearings present. Magnetic bearing technology is being developed worldwide and is considered an enabling technology for new engine designs. Using magnetic bearings, turbine and compressor spools can be radically redesigned to be significantly larger and stiffer with better damping and higher rotational speeds. These advances, a direct result of magnetic bearing technology, will allow significant increases in engine power and efficiency. Also, magnetic bearings allow for real-time, in-situ health monitoring of the system, lower maintenance costs and down time.

  4. RESOURCE-SAVING TECHNOLOGY FOR HIGH-SPEED HOT EXTRUSION OF BIMETALLIC ROD PARTS

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2016-01-01

    Full Text Available Processes of high-speed shaping changes and especially high-speed hot extrusion create efficient conditions for treatment of weakly plastic and poorly deformable materials which are widely used in tool making facilities. Due to the fact that high-speed stamping provides accurate billets with increased mechanical properties, it can be used as a technological process for manufacturing rod parts of die tooling operating under conditions of increased loads and wear. The purpose of the given paper is to carry out experimental investigations on the possibility to obtain a bimetallic rod tool where structural steel is considered as a basis of the tool and a working cavity is made of high-alloyed tool steel with its saving up to 90 %. A scheme of loading and geometry of conjugated surfaces of the composite billet have been developed in the paper. Technology for obtaining bimetallic rod parts of die tooling with deformation at speed of vд = 70–80 m/s and composite billet temperature of Т = (1150±20 ºС has been experimentally tested with formation of a compound due to plastic flow of two billet parts on contact surface with removal of surface oxide films. Microstructures of the bimetallic compounds obtained with the help of high-speed hot extrusion method for compositions of structural and high-alloy steels have been investigated and their high quality has been proved during the investigations. Dependences of micro-hardness distribution have been established outbound two steel contact plane in the zone of connection that are characterized by a minimum micro-hardness value in the connection joint. Availability of more plastic zone in the contact plane contributes to reduction of residual stresses due to their relaxation in this zone and higher joint strength.

  5. High-Pressure Turbulent Flame Speeds and Chemical Kinetics of Syngas Blends with and without Impurities

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Eric; Mathieu, Olivier; Morones, Anibal; Ravi, Sankar; Keesee, Charles; Hargis, Joshua; Vivanco, Jose

    2014-12-01

    This Topical Report documents the first year of the project, from October 1, 2013 through September 30, 2014. Efforts for this project included experiments to characterize the atmospheric-pressure turbulent flame speed vessel over a range of operating conditions (fan speeds and turbulent length scales). To this end, a new LDV system was acquired and set up for the detailed characterization of the turbulence field. Much progress was made in the area of impurity kinetics, which included a numerical study of the effect of impurities such as NO2, NO, H2S, and NH3 on ignition delay times and laminar flame speeds of syngas blends at engine conditions. Experiments included a series of laminar flame speed measurements for syngas (CO/H2) blends with various levels of CH4 and C2H6 addition, and the results were compared to the chemical kinetics model of NUI Galway. Also, a final NOx kinetics mechanism including ammonia was assembled, and a journal paper was written and is now in press. Overall, three journal papers and six conference papers related to this project were published this year. Finally, much progress was made on the design of the new high-pressure turbulent flame speed facility. An overall design that includes a venting system was decided upon, and the detailed design is in progress.

  6. Numerical analysis to determine the impact of land subsidence on high-speed railway routes in Beijing, China

    Directory of Open Access Journals (Sweden)

    C. Ye

    2015-11-01

    Full Text Available More than 10 high-speed railway routes with top speeds of 300 km h−1 are expected to be operational from Beijing by the year 2020. However, the safety of these routes is affected by the occurrence of land subsidence. This paper focuses on the Beijing–Tianjin Intercity High-Speed Railway (BTR, the first high-speed railway in China, to analyze the operational safety of high-speed railway routes by analyzing both regional land subsidence and local differential subsidence caused by groundwater drawing. The Beijing construction stratum is mainly composed of cohesive soil, and the BTR has a maximum accumulative subsidence of > 800 mm and a maximum subsidence rate of > 80 mm a−1. In this paper, finite-element software ABAQUS is used to analyze groundwater drawdown and land subsidence caused by local water drawing, and its effect on the bearing capacity of railway bridge pile foundations and the orbit concrete supporting course. The analysis provides a technical basis for developing prevention and control engineering measures against land subsidence so as to guarantee the safe operation of these high-speed railway routes.

  7. Ultra-high-speed Optical Signal Processing using Silicon Photonics

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Jensen, Asger Sellerup

    on silicon photonics. In particular we use nano-engineered silicon waveguides (nanowires) [1] enabling efficient phasematched four-wave mixing (FWM), cross-phase modulation (XPM) or self-phase modulation (SPM) for ultra-high-speed optical signal processing of ultra-high bit rate serial data signals. We show......— In supercomputers, the optical inter-connects are getting closer and closer to the processing cores. Today, a single supercomputer system has as many optical links as the whole worldwide web together, and it is envisaged that future computing chips will contain multiple electronic processor cores...... that silicon can indeed be used to control Tbit/s serial data signals [2], perform 640 Gbit/s wavelength conversion [3] 640 Gbit/s serial-to-parallel conversion [4], 160 Gbit/s packet switching as well as all-optical regeneration [5]. We will also discuss the performance limitations of crystalline silicon...

  8. High speed MSM photodetector based on Ge nanowires network

    Science.gov (United States)

    Dhyani, Veerendra; Das, Samaresh

    2017-05-01

    This paper presents the photoresponse characteristics of a high speed Ge nanowires (NWs) network metal-semiconductor-metal photodetector. Ge NWs with different diameters (30 nm-100 nm) were grown by a vapour-liquid-solid method on SiO2/Si (100) wafers. Responsivity up to 1.75 A W-1 has been observed for a 30 nm NWs device compared to 0.5 A W-1 for a 100 nm NWs detector. A large population of surface states results in higher responsivity in a smaller diameter NWs device. The high gain in photocurrent has been explained using back-to-back Schottky junctions in a NWs network. The 30 nm NWs detector shows a fast photoresponse with a rise time of 95 μs and a fall time of 100 μs. The observed diameter-dependent time response in network NWs devices has been explained using barrier-dominant photo-conductance.

  9. Physiological consequences of military high-speed boat transits.

    Science.gov (United States)

    Myers, Stephen D; Dobbins, Trevor D; King, Stuart; Hall, Benjamin; Ayling, Ruth M; Holmes, Sharon R; Gunston, Tom; Dyson, Rosemary

    2011-09-01

    The purpose of this study was to investigate the consequences of a high-speed boat transit on physical performance. Twenty-four Royal Marines were randomly assigned to a control (CON) or transit (TRAN) group. The CON group sat onshore for 3 h whilst the TRAN group completed a 3-h transit in open-boats running side-by-side, at 40 knots in moderate-to-rough seas, with boat deck and seat-pan acceleration recorded. Performance tests (exhaustive shuttle-run, handgrip, vertical-jump, push-up) were completed pre- and immediately post-transit/sit, with peak heart rate (HRpeak) and rating of perceived exertion (RPE) recorded. Serial blood samples (pre, 24, 36, 48, 72 h) were analyzed for creatine kinase (CK) activity. The transit was typified by frequent high shock impacts, but moderate mean heart rates (boat transits.

  10. High-Speed, Three Dimensional Object Composition Mapping Technology

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, M Y

    2001-02-14

    This document overviews an entirely new approach to determining the composition--the chemical-elemental, isotopic and molecular make-up--of complex, highly structured objects, moreover with microscopic spatial resolution in all 3 dimensions. The front cover depicts the new type of pulsed laser system at the heart of this novel technology under adjustment by Alexis Wynne, and schematically indicates two of its early uses: swiftly analyzing the 3-D composition governed structure of a transistor circuit with both optical and mass-spectrometric detectors, and of fossilized dinosaur and turtle bones high-speed probed by optical detection means. Studying the composition-cued 3-D micro-structures of advanced composite materials and the microscopic scale composition-texture of biological tissues are two near-term examples of the rich spectrum of novel applications enabled by this field-opening analytic tool-set.

  11. High Speed Running and Sprinting Profiles of Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Miñano-Espin Javier

    2017-08-01

    Full Text Available Real Madrid was named as the best club of the 20th century by the International Federation of Football History and Statistics. The aim of this study was to compare if players from Real Madrid covered shorter distances than players from the opposing team. One hundred and forty-nine matches including league, cup and UEFA Champions League matches played by the Real Madrid were monitored during the 2001-2002 to the 2006-2007 seasons. Data from both teams (Real Madrid and the opponent were recorded. Altogether, 2082 physical performance profiles were examined, 1052 from the Real Madrid and 1031 from the opposing team (Central Defenders (CD = 536, External Defenders (ED = 491, Central Midfielders (CM = 544, External Midfielders (EM = 233, and Forwards (F = 278. Match performance data were collected using a computerized multiple-camera tracking system (Amisco Pro®, Nice, France. A repeated measures analysis of variance (ANOVA was performed for distances covered at different intensities (sprinting (>24.0 km/h and high-speed running (21.1-24.0 km/h and the number of sprints (21.1-24.0 km/h and >24.0 km/h during games for each player sectioned under their positional roles. Players from Real Madrid covered shorter distances in high-speed running and sprint than players from the opposing team (p 0.01 from Real Madrid covered shorter distances in high-intensity running and sprint and performed less sprints than their counterparts. Finally, no differences were found in the high-intensity running and sprint distances performed by players from Real Madrid depending on the quality of the opposition.

  12. Ultra-high-speed wavelength conversion in a silicon photonic chip

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Galili, Michael

    2011-01-01

    with high data integrity and indicate that high-speed operation can be obtained at moderate power levels where nonlinear absorption due to TPA and free-carrier absorption (FCA) is not detrimental. This demonstration can potentially enable highspeed optical networks on a silicon photonic chip.......We have successfully demonstrated all-optical wavelength conversion of a 640-Gbit/s line-rate return-to-zero differential phase-shift keying (RZ-DPSK) signal based on low-power four wave mixing (FWM) in a silicon photonic chip with a switching energy of only ~110 fJ/bit. The waveguide dispersion...... of the silicon nanowire is nano-engineered to optimize phase matching for FWM and the switching power used for the signal processing is low enough to reduce nonlinear absorption from twophoton- absorption (TPA). These results demonstrate that high-speed wavelength conversion is achievable in silicon chips...

  13. A Parallel Strategy for High-speed Interpolation of CNC Using Data Space Constraint Method

    Directory of Open Access Journals (Sweden)

    Shuan-qiang Yang

    2013-12-01

    Full Text Available A high-speed interpolation scheme using parallel computing is proposed in this paper. The interpolation method is divided into two tasks, namely, the rough task executing in PC and the fine task in the I/O card. During the interpolation procedure, the double buffers are constructed to exchange the interpolation data between the two tasks. Then, the data space constraint method is adapted to ensure the reliable and continuous data communication between the two buffers. Therefore, the proposed scheme can be realized in the common distribution of the operation systems without real-time performance. The high-speed and high-precision motion control can be achieved as well. Finally, an experiment is conducted on the self-developed CNC platform, the test results are shown to verify the proposed method.

  14. Development and Evaluation of Bus Operation Control System Based on Cooperative Speed Guidance

    Directory of Open Access Journals (Sweden)

    Jing Teng

    2015-01-01

    Full Text Available Buses often have strong bunching or large interval tendency when traveling further along the route. To restrain this further deterioration of operation service, this paper developed a bus operation control system to dynamically adjust bus speed, bus dwell time, and traffic signal timings along the running path. In addition, a simulation platform was developed to evaluate the proposed control system with the actual data collected from bus route number 210 in Shanghai. The simulation results show that the proposed control system can mitigate the amplification trend of the headway deviation along the route to produce headways within a given tolerance.

  15. Propulsion challenges and opportunities for high-speed transport aircraft

    Science.gov (United States)

    Strack, William C.

    1987-01-01

    For several years there was a growing interest in the subject of efficient sustained supersonic cruise technology applied to a high-speed transport aircraft. The major challenges confronting the propulsion community for supersonic transport (SST) applications are identified. Both past progress and future opportunities are discussed in relation to perceived technology shortfalls for an economically successful SST that satisfies environmental constraints. A very large improvement in propulsion system efficiency is needed both at supersonic and subsonic cruise conditions. Toward that end, several advanced engine concepts are being considered that, together with advanced discipline and component technologies, promise at least 40 percent better efficiency that the Concorde engine. The quest for higher productivity through higher speed is also thwarted by the lack of a conventional, low-priced fuel that is thermally stable at the higher temperatures associated with faster flight. Airport noise remains a tough challenge because previously researched concepts fall short of achieving FAR 36 Stage 3 noise levels. Innovative solutions may be necessary to reach acceptably low noise. While the technical challenges are indeed formidable, it is reasonable to assume that the current shortfalls in fuel economy and noise can be overcome through an aggressive propulsion research program.

  16. Numerical Simulation of Oil Jet Lubrication for High Speed Gears

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli

    2015-01-01

    Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

  17. Changes of indicators of high-speed and high-speed and power preparedness at volleyball players of 12–13 years old

    OpenAIRE

    Oleg Shevchenko

    2016-01-01

    Purpose: to define changes of indicators of high-speed and high-speed and power preparedness of volleyball players of 12–13 years old. Material & Methods: the test exercises, which are recommended by the training program of CYSS on volleyball, were used for the definition of the level of development of high-speed and high-speed and power abilities of volleyball players. 25 young volleyball players from the group of the previous basic preparation took part in the experiment. Sports experie...

  18. Lighting Systems For High Speed Photography Applying Special Metal Halide Discharge Lamps

    Science.gov (United States)

    Gillum, Keith M.; Steuernagel, K. H.

    1983-03-01

    High speed photography requires, in addition to a good color quality of the light source, a very high level of illumination. Conventional lighting systems utilizing incandescent lamps or other metal halide lamp types has inherent problems of inefficient light output or poor color quality. Heat generated by incandescent lamps and the power these sources require drive up operating and installation costs. A most economical and practical solution was devised by using the metal halide discharge lamp developed by OSRAM, GmbH of Munich, West Germany. This lamp trade marked the HMITM Metallogen was primarily developed for the needs of the television and motion picture film industry. Due to their high efficiency and other consistent operating qualities these lamps also fulfill the needs of high speed photography, e.g. in crash test facilities, when special engineering activities are carried out. The OSRAM HMITM lamp is an AC discharge metal halide lamp with rare earth additives to increase both the efficiency and light output qualities. Since the lamp is an AC source, a special method had to be developed to overcome the strobing effect, which is normal for AC lamps given their modulated light output, when used with high speed cameras, (e.g. with >1000 fps). This method is based on an increased frequency for the lamp supply voltage coupled with a mix of the light output achieved using a multiphase mains power supply. First developed in 1977, this system using the OSRAM HMITM lamps was installed in a crash test facility of a major automotive manufacturer in West Germany. The design resulted in the best lighting and performance ever experienced. Since that time several other motor companies have made use of this breakthrough. Industrial and scientific users are now considering additional applications use of this advanced high speed lighting system.

  19. Examination of Operation Quality for High-frequent Railway Operation

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.

    2009-01-01

    The examination of operation quality for high-frequent operation requires other approaches than the typical evaluation of punctuality (trains on time) and reliability (operated trains). This is because passengers in high-frequent railway systems do not necessarily notice train delays as they just...... take the first train in their direction. The article examines four different approaches to examine operation quality for high-frequent operation that are based on the experiences of the passengers. These approaches are the service frequency of the operation, travel time extension, a combination...... operation simulation software. Combining the passenger delay model with simulation software gives the possibility to forecast future infrastructure and operation scenarios which make it possible to improve the planning....

  20. High-speed single-pixel digital holography

    Science.gov (United States)

    González, Humberto; Martínez-León, Lluís.; Soldevila, Fernando; Araiza-Esquivel, Ma.; Tajahuerce, Enrique; Lancis, Jesús

    2017-06-01

    The complete phase and amplitude information of biological specimens can be easily determined by phase-shifting digital holography. Spatial light modulators (SLMs) based on liquid crystal technology, with a frame-rate around 60 Hz, have been employed in digital holography. In contrast, digital micro-mirror devices (DMDs) can reach frame rates up to 22 kHz. A method proposed by Lee to design computer generated holograms (CGHs) permits the use of such binary amplitude modulators as phase-modulation devices. Single-pixel imaging techniques record images by sampling the object with a sequence of micro-structured light patterns and using a simple photodetector. Our group has reported some approaches combining single-pixel imaging and phase-shifting digital holography. In this communication, we review these techniques and present the possibility of a high-speed single-pixel phase-shifting digital holography system with phase-encoded illumination. This system is based on a Mach-Zehnder interferometer, with a DMD acting as the modulator for projecting the sampling patterns on the object and also being used for phase-shifting. The proposed sampling functions are phaseencoded Hadamard patterns generated through a Lee hologram approach. The method allows the recording of the complex amplitude distribution of an object at high speed on account of the high frame rates of the DMD. Reconstruction may take just a few seconds. Besides, the optical setup is envisaged as a true adaptive system, which is able to measure the aberration induced by the optical system in the absence of a sample object, and then to compensate the wavefront in the phasemodulation stage.

  1. High-speed neutron Laue diffraction comes of age

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Garry J. [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)]. E-mail: mcintyre@ill.fr; Lemee-Cailleau, Marie-Helene [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Wilkinson, Clive [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France): Department of Chemistry, University of Durham, Durham DH1 3LE (United Kingdom)

    2006-11-15

    The first years of operation of the Laue diffractometer VIVALDI at the ILL are reviewed. Neutron Laue diffraction with image-plate detection on a thermal beam is now a high-performance technique especially well suited to small crystals, rapid chemical crystallography, reciprocal-space surveys and studies of structural and magnetic phase transitions.

  2. Oxide confined 850-nm VCSELs for high-speed datacom applications

    Science.gov (United States)

    Moser, Philip; Mutig, Alex; Lott, James A.; Blokhin, Sergey; Fiol, Gerrit; Nadtochiy, Alexey M.; Ledentsov, Nikolai N.; Bimberg, Dieter

    2010-04-01

    Vertical cavity surface emitting lasers (VCSELs) are low cost and reliable light sources for high-speed local area and storage area network (LAN/SAN) optical fiber data communication systems and all other short-reach high-speed data transfer applications. The intrinsic limitations of copper-based electrical links at data rates exceeding 10 Gbit/s leads to a progressive movement wherein optical communication links replace traditional short-reach (300 m or shorter) copper interconnects. The wavelength of 850 nm is the standard for LAN/SAN applications as well as for several other evolving short-reach application areas including Fibre Channel, InfiniBand, Universal Serial Bus (optical USB), and active optical cables. Here we present our recent results on 850 nm oxide-confined VCSELs operating at data bit rates up to 40 Gbit/s at low current densities of ~10 kA/cm2 ensuring device reliability and long-term stability based on conventional industry certification specifications. The relaxation resonance frequencies, damping factors, and parasitic cut-off frequencies are determined for VCSELs with oxide-confined apertures of various diameters. At the highest optical modulation rates the VCSELs' high speed operation is limited by parasitic cut-off frequencies of 24-28 GHz. We believe that by further reducing device parasitics we will produce current modulated VCSELs with optical modulation bandwidths larger than 30 GHz and data bit rates beyond 40 Gbit/s.

  3. High-Speed Rail for Central and Eastern European Countries: A Conference Report

    Directory of Open Access Journals (Sweden)

    Jandová Monika

    2016-09-01

    Full Text Available The European transport strategy promotes the role of railways and expects that the key role in passenger transport should be played by high-speed rail (HSR. Although the core network of high-speed lines has already been built and is operating in Western Europe, there has been little coverage so far in Central and Eastern Europe (CEE. The aim of the conference “High-Speed Rail for CEE Countries” that took place in Prague in June 2016 was to put together academics, policy-makers, and practitioners interested in HSR and to formulate recommendations for CEE countries based on West European countries’ experience. Based on the conference presentations and subsequent discussion, the following conclusions were formulated. Firstly, there are many crucial differences in national HSR build-up and operation, which means that former experience of Western Europe is not directly applicable to CEE countries. Secondly, in comparing presentations discussing experiences in France, Britain, Italy, and Germany, it was concluded that the German approach-upgrading existing lines where possible and only building new lines for bottleneck sections-was the most likely appropriate solution in CEE. Lastly, CEE has the additional problem of many border crossings, with a reduction of traffic in comparison with purely domestic routes, and this effect has to be taken into account.

  4. Integration and test of high-speed transmitter electronics for free-space laser communications

    Science.gov (United States)

    Soni, Nitin J.; Lizanich, Paul J.

    1994-01-01

    The NASA Lewis Research Center in Cleveland, Ohio, has developed the electronics for a free-space, direct-detection laser communications system demonstration. Under the High-Speed Laser Integrated Terminal Electronics (Hi-LITE) Project, NASA Lewis has built a prototype full-duplex, dual-channel electronics transmitter and receiver operating at 325 megabit S per second (Mbps) per channel and using quaternary pulse-position modulation (QPPM). This paper describes the integration and testing of the transmitter portion for future application in free-space, direct-detection laser communications. A companion paper reviews the receiver portion of the prototype electronics. Minor modifications to the transmitter were made since the initial report on the entire system, and this paper addresses them. The digital electronics are implemented in gallium arsenide integrated circuits mounted on prototype boards. The fabrication and implementation issues related to these high-speed devices are discussed. The transmitter's test results are documented, and its functionality is verified by exercising all modes of operation. Various testing issues pertaining to high-speed circuits are addressed. A description of the transmitter electronics packaging concludes the paper.

  5. High-speed cinematography of gas-metal atomization

    Energy Technology Data Exchange (ETDEWEB)

    Ting, Jason [ALCOA Specialty Metals Division, 100 Technical Drive, Alcoa Center, PA 15069 (United States)]. E-mail: jason.ting@alcoa.com; Connor, Jeffery [Material Science Engineering Department, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Ridder, Stephen [Metallurgical Processing Group, NIST, 100 Bureau Dr. Stop 8556, Gaithersburg, MD 20899 (United States)

    2005-01-15

    A high-speed cinematographic footage of a 304L stainless steel gas atomization, recorded at the National Institute of Standard and Technology (NIST), was analyzed using a discrete Fourier transform (DFT) algorithm. The analysis showed the gas atomization process possesses two prominent frequency ranges of melt oscillation (pulsation). A low-frequency oscillation in the melt flow occurring between 5.41 and 123 Hz, with a dominant frequency at 9.93 Hz, was seen in the recirculation zone adjacent to the melt orifice. A high-frequency melt oscillation range was observed above 123 Hz, and was more prominent one melt-tip-diameter downstream in the melt atomization image than upstream near the melt tip. This high-frequency range may reflect the melt atomization frequency used to produce finely atomized powder. This range also included a prominent high frequency at 1273 Hz, which dominated in the image further away downstream from the melt tip. This discrete high-frequency oscillation is most probably caused by the aeroacoustic ''screech'' phenomenon, intrasound (<20 kHz), a result of the atomizing gas jets undergoing flow resonance. It is hypothesized that this discrete intrinsic aeroacoustic tone may enhance melt breakup in the atomization process with evidence of this fact in the melt images.

  6. High-speed Integrated Circuits for electrical/Optical Interfaces

    DEFF Research Database (Denmark)

    Jespersen, Christoffer Felix

    2008-01-01

    of LC-oscillators with oscillator criteria, phase noise and different topologies are given as background. The theory of PLL circuits is also presented. Guidelines and suggestions for static divider, VCO, LA and CDR design are presented using static divider, 50-100 GHz VCO and 100Gb/s LA+CDR circuits......This thesis is a continuation of the effort to increase the bandwidth of communicationnetworks. The thesis presents the results of the design of several high-speed electrical ircuits for an electrical/optical interface. These circuits have been a contribution to the ESTA project in collaboration...... circuits at the receiver interface, though VCOs are also found in the transmitter where a multitude of independent sources have to be mutually synchronized before multiplexing. The circuits are based on an InP DHBT process (VIP-2) supplied by Vitesse and made publicly available as MPW. The VIP-2 process...

  7. Simplified Dynamic Model for High-Speed Checkweigher

    Science.gov (United States)

    Yamakawa, Yuji; Yamazaki, Takanori

    In this paper, we concern with the dynamic behaviors of a high speed mass measurement system with conveyor belt (a checkweigher). The goal of this paper is to construct a simple model of the measurement system so as to duplicate a response of the system. The checkweigher with electromagnetic force compensation can be approximated by the combined spring-mass-damper systems as the physical model, and the equation of motion is derived. The model parameters (a damping coefficient and a spring constant) can be obtained from the experimental data for open-loop system. Finally, the validity of the proposed model can be confirmed by comparison of the simulation results with the realistic responses. The simple dynamic model obtained offers practical and useful information to examine control scheme.

  8. AGAINTS AND FOR THE HIGH SPEED TRAINS’ MULTIMPLICATION

    Directory of Open Access Journals (Sweden)

    Benea Ciprian

    2008-05-01

    Full Text Available In this exposure we intend to make visible the situation in which global warming is given by road and air transport, how could be revitalized railways, and how high speed trains could become a preferred mode of transport. But there is manifesting an opposition to railway development, nurtured by different interests, ranking from governments themselves, to oil importing countries, oil exporting countries, oil companies with their colligate partners situated along the oil distribution chain. But, there could be identified some voices which could create themselves the possibility to speak lauder in order to promote railway transportation. The greens, NGOs, the epistemic communities, for example, could unite their force to make something in order to provide the framework for rail transportation’s development, and for road and air transport reduction, for the benefit of while humankind.

  9. Design implications of high-speed digital PPM

    Science.gov (United States)

    Sibley, Martin J. N.

    1993-11-01

    Work in the area of digital pulse position modulation (digital PPM) has shown that this type of modulation can yield sensitivities that are typically 4 - 5 dB better than an equivalent PCM system. Recent experimental work has shown that the receiver in a digital PPM system does not need to have a wide bandwidth. Instead, the bandwidth can be very low so that the receiver is effectively impulsed by the digital PPM signal. The advent of very high speed Si digital ICs, and fast lasers, means that digital PPM can now be used to code gigabit PCM signals. This paper presents original theoretical results for a digital PPM system coding 1 Gbit/s PCM signals into 8 Gbit/s digital PPM signals. The paper also addresses the difficulties that the system designer is likely to encounter, and discusses some possible solutions.

  10. Towards high-speed autonomous navigation of unknown environments

    Science.gov (United States)

    Richter, Charles; Roy, Nicholas

    2015-05-01

    In this paper, we summarize recent research enabling high-speed navigation in unknown environments for dynamic robots that perceive the world through onboard sensors. Many existing solutions to this problem guarantee safety by making the conservative assumption that any unknown portion of the map may contain an obstacle, and therefore constrain planned motions to lie entirely within known free space. In this work, we observe that safety constraints may significantly limit performance and that faster navigation is possible if the planner reasons about collision with unobserved obstacles probabilistically. Our overall approach is to use machine learning to approximate the expected costs of collision using the current state of the map and the planned trajectory. Our contribution is to demonstrate fast but safe planning using a learned function to predict future collision probabilities.

  11. High-speed counters in Fibonacci numerical system

    Science.gov (United States)

    Azarov, Olexiy; Chernyak, Olexandr; Komada, Paweł; Kozhambardiyeva, Miergul; Kalizhanova, Aliya

    2017-08-01

    Possibility of executing the carriers and borrowings by means of elementary additive transformations in the process of calculation in Fibonacci numerical system is substantiated. Methods of counting in the given numerical system, based on the usage of information redundancy are suggested. The methods consist in the fact that at every step executed all possible elementary addition transformations of code in the counter simultaneously with adding one. The suggested methods enable to construct up-, down- and up/down counters with high speed, independent on the data capacity and small hardware cost that linearly grow with the increase of the capacity. Schemes of structural organization of one digit for each of the suggested methods are given.

  12. Experimental Study of the Influence of Speed and Load on Thermal Behavior of High-Speed Helical Gear Trains

    Science.gov (United States)

    Handschuh, R.; Kilmain, C.

    2005-01-01

    An experimental effort has been conducted on an aerospace-quality helical gear train to investigate the thermal behavior of the gear system as speed, load, and lubricant flow rate were varied. Temperature test data from a helical gear train at varying speeds and loads (to 5000 hp and 15000 rpm) was collected using thermocouple rakes and axial arrays. The instrumentation was able to capture the radial and axial expelled lubricant-air environment (fling-off lubricant) that is expelled during the gear meshing process. Effects of operational characteristics are presented.

  13. Parallel scanning laser ophthalmoscope (PSLO) for high-speed retinal imaging

    NARCIS (Netherlands)

    Vienola, K.V.; Braaf, Boy; Damodaran, Mathi; Vermeer, Koenraad A.; de Boer, Johannes F.

    2014-01-01

    Purpose High-speed imaging of the retina is crucial for obtaining high quality images in the presence of eye motion. To improve the speed of traditional scanners, a high-speed ophthalmic device is presented using a digital micro-mirror device (DMD) for confocal imaging with multiple simultaneous

  14. 49 CFR 236.1007 - Additional requirements for high-speed service.

    Science.gov (United States)

    2010-10-01

    ... by this subpart, and which have been utilized on high-speed rail systems with similar technical and... 49 Transportation 4 2010-10-01 2010-10-01 false Additional requirements for high-speed service..., AND APPLIANCES Positive Train Control Systems § 236.1007 Additional requirements for high-speed...

  15. Dual-camera system for high-speed imaging in particle image velocimetry

    CERN Document Server

    Hashimoto, K; Hara, T; Onogi, S; Mouri, H

    2012-01-01

    Particle image velocimetry is an important technique in experimental fluid mechanics, for which it has been essential to use a specialized high-speed camera. However, the high speed is at the expense of other performances of the camera, i.e., sensitivity and image resolution. Here, we demonstrate that the high-speed imaging is also possible with a pair of still cameras.

  16. Regulation of the Dynamic Live Load Factor for Calculation of Bridge Structures on High-Speed Railway Mainlines

    Science.gov (United States)

    Dyachenko, Leonid K.; Benin, Andrey V.

    2017-06-01

    When the high-speed railway traffic is being organized, it becomes necessary to elaborate bridge design standards for high-speed railways (HSR). Methodology of studying the issues of HSR bridge design is based on the comprehensive analysis of domestic research as well as international experience in design, construction and operation of high-speed railways. Serious requirements are imposed on the HSR artificial structures, which raise a number of scientific tasks associated mainly with the issues of the dynamic interaction of the rolling stock and the bridge elements. To ensure safety of traffic and reliability of bridges during the whole period of operation one needs to resolve the dynamic problems of various types of high-speed trains moving along the structures. The article analyses dependences of the magnitude of inertial response on the external stress parameters and proposes a simplified method of determination of the dynamic live load factor caused by the passage of high-speed trains. The usefulness of the given research arises from the reduction of complexity of the complicated dynamic calculations needed to describe a high-speed train travelling along the artificial structures.

  17. Regulation of the Dynamic Live Load Factor for Calculation of Bridge Structures on High-Speed Railway Mainlines

    Directory of Open Access Journals (Sweden)

    Dyachenko Leonid K.

    2017-06-01

    Full Text Available When the high-speed railway traffic is being organized, it becomes necessary to elaborate bridge design standards for high-speed railways (HSR. Methodology of studying the issues of HSR bridge design is based on the comprehensive analysis of domestic research as well as international experience in design, construction and operation of high-speed railways. Serious requirements are imposed on the HSR artificial structures, which raise a number of scientific tasks associated mainly with the issues of the dynamic interaction of the rolling stock and the bridge elements. To ensure safety of traffic and reliability of bridges during the whole period of operation one needs to resolve the dynamic problems of various types of high-speed trains moving along the structures. The article analyses dependences of the magnitude of inertial response on the external stress parameters and proposes a simplified method of determination of the dynamic live load factor caused by the passage of high-speed trains. The usefulness of the given research arises from the reduction of complexity of the complicated dynamic calculations needed to describe a high-speed train travelling along the artificial structures.

  18. Design and Development of a High Speed Sorting System Based on Machine Vision Guiding

    Science.gov (United States)

    Zhang, Wenchang; Mei, Jiangping; Ding, Yabin

    In this paper, a vision-based control strategy to perform high speed pick-and-place tasks on automation product line is proposed, and relevant control software is develop. Using Delta robot to control a sucker to grasp disordered objects from one moving conveyer and then place them on the other in order. CCD camera gets one picture every time the conveyer moves a distance of ds. Objects position and shape are got after image processing. Target tracking method based on "Servo motor + synchronous conveyer" is used to fulfill the high speed porting operation real time. Experiments conducted on Delta robot sorting system demonstrate the efficiency and validity of the proposed vision-control strategy.

  19. Linearity Analysis on a Series-Split Capacitor Array for High-Speed SAR ADCs

    Directory of Open Access Journals (Sweden)

    Yan Zhu

    2010-01-01

    Full Text Available A novel Capacitor array structure for Successive Approximation Register (SAR ADC is proposed. This circuit efficiently utilizes charge recycling to achieve high-speed of operation and it can be applied to high-speed and low-to-medium-resolution SAR ADC. The parasitic effects and the static linearity performance, namely, the INL and DNL, of the proposed structure are theoretically analyzed and behavioral simulations are performed to demonstrate its effectiveness under those nonidealities. Simulation results show that to achieve the same conversion performance the proposed capacitor array structure can reduce the average power consumed from the reference ladder by 90% when compared to the binary-weighted splitting capacitor array structure.

  20. Design and Build of an Electrical Machines’ High Speed Measurement System at Low Cost

    Directory of Open Access Journals (Sweden)

    Constantinos C. Kontogiannis

    2014-01-01

    Full Text Available The principal objective of this paper is to demonstrate the capability of high speed measurement and acquisition equipment design and build in the laboratory at a very low cost. The presented architecture employees highly integrated market components eliminating thus the complexity of the hardware and software stack. The key element of the proposed system is a Hi-Speed USB to Serial/FIFO development module that is provided with full software and driver support for most popular operating systems. This module takes over every single task needed to get the data from the A/D to the user software gluelessly and transparently, solving this way the most difficult problem in data acquisition systems which is the fast and reliable communication with a host computer. Other ideas tested and included in this document offer Hall Effect measuring solutions using some excellent features and very low cost ICs widely available on the market today.

  1. High Speed Rail Learning System (HSRLS – Taking Advantage of Online Technologies in Railway Education

    Directory of Open Access Journals (Sweden)

    Pasi T. Lautala, Ph.D., P.E.

    2015-06-01

    Full Text Available The United States has taken initial steps toward developing a high speed rail (HSR network, but the domestic workforce experience and institutional knowledge necessary for the planning, design, construction, and operations of HSR is underdeveloped. This paper describes and provides preliminary assessment of the High Speed Rail Learning System (HSRLS, a demonstration project that seeks to address gaps in HSR knowledge and skills in the US. The HSRLS developers designed an online education system to serve as a clearinghouse for rail-related information and content, connect teachers, trainers, and students at pre-, and postgraduate levels, and to collect demographic and professional information on groups and individuals interested in HSR. The paper explores the technology review, selection process, and content developed. Website visits and demographic information from over 4,000 unique individuals and 600 HSRLS course registrations are analyzed and assessed.

  2. Design of high-speed turnouts and crossings

    Science.gov (United States)

    Raif, Lukáš; Puda, Bohuslav; Havlík, Jiří; Smolka, Marek

    2017-09-01

    Recently, the new ways to improve the railway switches and crossings have been sought, as the railway transport increases its operating speed. The expectation of these adjustments is to decrease the dynamic load, which usually increases together with velocity, and this influences the comfort of the vehicle passage, the wear of the structural parts and the cost of maintenance. These adjustments are primarily the turnout elements such as the optimized geometry of the turnout branch line by means of transition curves application, which minimizes the lateral acceleration during the vehicle passage through the track curve. The rail inclination is solved either by means of inclination in fastening system, or by machining of the rail head shape, because this ways of adjustment retain the wheel-rail interaction characteristics along the whole length of the turnout. Secondly, it is the crossing with movable part, which excludes the interruption of the running surface and optimization of the railway stiffness throughout the whole turnout length as well. We can see that the different stiffness along the turnout influences the dynamic load and it is necessary to optimize the discontinuities in the stiffness along the whole length of the turnout. For this purpose, the numeric modeling is carried out to seek the areas with the highest stiffness and subsequently, the system of stiffness optimization will be designed.

  3. SELF-ALIGNED SINGLE CRYSTAL CONTACTED HIGH-SPEED SILICON BIPOLAR TRANSISTOR UTILIZING SELECTIVE (SEG) AND CONFINED SELECTIVE EPITAXIAL GROWTH (CLSEG)

    OpenAIRE

    Siekkinen, James W.; Neudeck, Gerold W.

    1992-01-01

    A new high-speed bipolar transistor structure, the ELOBJT-3, is proposed as a novel application of selective epitaxy technology. The new structure is greatly suited to high-speed ECL circuits, where Ccb, C,, and Rbx are of prime importance. The reduction of these parasitics to their nearly theoretical minimums is accomplished through the use of dielectric isolation and concentric contacting. For extremely high speed operation, dimensions can be scaled to sub-micron size due to the completely ...

  4. An Ultra-High Speed Whole Slide Image Viewing System

    Directory of Open Access Journals (Sweden)

    Yukako Yagi

    2012-01-01

    Full Text Available Background: One of the goals for a Whole Slide Imaging (WSI system is implementation in the clinical practice of pathology. One of the unresolved problems in accomplishing this goal is the speed of the entire process, i.e., from viewing the slides through making the final diagnosis. Most users are not satisfied with the correct viewing speeds of available systems. We have evaluated a new WSI viewing station and tool that focuses on speed.

  5. Design of high-speed planing hulls for the improvement of resistance and seakeeping performance

    Directory of Open Access Journals (Sweden)

    Dong Jin Kim

    2013-03-01

    Full Text Available High-speed vessels require good resistance and seakeeping performance for safe operations in rough seas. The resistance and seakeeping performance of high-speed vessels varies significantly depending on their hull forms. In this study, three planing hulls that have almost the same displacement and principal dimension are designed and the hydrodynamic characteristics of those hulls are estimated by high-speed model tests. All model ships are deep-V type planing hulls. The bows of no.2 and no.3 model ships are designed to be advantageous for wave-piercing in rough water. No. 2 and no. 3 model ships have concave and straight forebody cross-sections, respectively. And length-to-beam ratios of no.2 and no.3 models are larger than that of no.1 model. In calm water tests, running attitude and resistance of model ships are measured at various speeds. And motion tests in regular waves are performed to measure the heave and pitch motion responses of the model ships. The required power of no.1 (VPS model is smallest, but its vertical motion amplitudes in waves are the largest. No.2 (VWC model shows the smallest motion amplitudes in waves, but needs the greatest power at high speed. The resistance and seakeeping performance of no.3 (VWS model ship are the middle of three model ships, respectively. And in regular waves, no.1 model ship experiences ‘fly over’ phenomena around its resonant frequency. Vertical accelerations at specific locations such as F.P., center of gravity of model ships are measured at their resonant frequency. It is necessary to measure accelerations by accelerometers or other devices in model tests for the accurate prediction of vertical accelerations in real ships.

  6. New York state high-speed surface transportation study: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    In 1990, New York State Governor Mario M. Cuomo created an interagency task force under the leadership of Lt. Governor Stan Lundine to investigate the potential of high speed ground transportation (HSGT) systems. Building on information from previous agency activities, including consultant efforts contracted by the New York State Energy Research and Development Authority (NYSERDA), the New York State Thruway Authority (NYSTA), and in-house analyses performed by New York State Department of Transportation (NYSDOT), the task force focused on the corridor between New York City and the Niagara Frontier. In December 1991, NYSERDA issued a contract for a study of high speed ground transportation options for New York State. The study`s objective was to assess potential rights-of-way, ridership, energy and environmental impacts, economic benefits, capital, operating, and maintenance costs, and financial viability of HSGT systems. This study builds upon and supplements previous and on-going HSGT activities conducted by the members of the interagency task force. These activities include: Maglev Technical and Economic Feasibility Study (NYSERDA); Maglev Demonstration Site Investigation (NYSTA); and New York/Massachusetts High Speed Ground Transportation Study (NYSDOT). This study is intended to verify and refine previous information and analyses and provide supplemental information and insights to be used in determining if additional investigation and activities involving HSGT are desirable for New York State. This study evaluates HSGT technologies capable of speeds significantly higher than those achieved with the present rail system. Three HSGT categories are used in this study: incremental rail improvement, very high-speed rail, and Maglev.

  7. High-Speed, Low-Power Digitizer II (2007037) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future detectors and arrays for visible, IR, and submillimeter imaging and spectroscopy require much higher speed digitizers than are currently available. In...

  8. High-Speed, Low-Power Digitizer (9725) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future detectors and arrays for visible, IR, and submillimeter imaging and spectroscopy require much higher speed digitizers than are currently available. In...

  9. Efficient, high-speed ablation of soft tissue with few-microjoule, femtosecond pulse bursts

    CERN Document Server

    Kerse, Can; Kalaycıoğlu, Hamit; Aşık, Mehmet D; Akçaalan, Önder; Ilday, F Ömer

    2014-01-01

    Femtosecond pulses hold great promise for high-precision tissue removal. However, ablation rates are severely limited by the need to keep average laser power low to avoid collateral damage due to heat accumulation. Furthermore, previously reported pulse energies preclude delivery in flexible fibers, hindering in vivo operation. Both of these problems can be addressed through use of groups of high-repetition-rate pulses, or bursts. Here, we report a novel fiber laser and demonstrate ultrafast burst-mode ablation of brain tissue at rates approaching 1 mm$^3$/min, an order of magnitude improvement over previous reports. Burst mode operation is shown to be superior in terms of energy required and avoidance of thermal effects, compared to uniform repetition rates. These results can pave the way to in vivo operation at medically relevant speeds, delivered via flexible fibers to surgically hard-to-reach targets, or with simultaneous magnetic resonance imaging.

  10. Field-tested technology for gas compression: using high-speed induction motors to replace conventional solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Karina Velloso; Pradurat, Jean Francois [Institut National Polytechnique de Lorraine (INPL), Nancy (France). Converteam Rotating Machines Division

    2009-07-01

    Industry leaders are all concerned about rationalization of electric power use, increase of efficiency and flexibility, environmental impact, installations size and maintenance efforts diminution. The high-speed induction motors are a good solution when addressing these parameters. How this technology works and how using it can help pipelines operators meet growing operational and environmental challenges is the main subject of this paper, that also explain how it can be used to replace conventional solutions. As a conclusion the future opportunities of electric high-speed drive systems application in production, transport and storage for natural gas industry are going to be discussed. (author)

  11. Progress on High-Speed 980 nm VCSELs for Short-Reach Optical Interconnects

    Directory of Open Access Journals (Sweden)

    Alex Mutig

    2011-01-01

    Full Text Available Progress of high-speed vertical cavity surface emitting lasers (VCSEL operating around 980 nm is reviewed. A special focus is on their applications for future short-reach optical interconnects, for example, in high-performance computers (HPC. The wavelength of 980 nm has fundamental advantages for these applications and plays a significant role in VCSEL research today. The present data rates of 980 nm VCSELs exceed 40 Gbit/s, and excellent temperature stability has been reported. The major concepts leading to these impressive developments are presented.

  12. An On-Chip Memory for Testing of High-Speed Mixed-Signal Circuits

    OpenAIRE

    Omar, Omar Jaber

    2013-01-01

    Mixed-signal processing systems especially data converters can be reliably tested at high frequencies using on-chip testing schemes based on memory. In this thesis, an on-chip testing strategy based on shift registers/memory (2 k bits) has been proposed for digital-to-analog converters (DACs) operating at 5 GHz. The proposed design uses word length of 8 bits in order to test DAC at high speed of 5 GHz. The proposed testing strategy has been designed in standard 65 nm CMOS technology with addi...

  13. Plastic straw: future of high-speed signaling

    Science.gov (United States)

    Song, Ha Il; Jin, Huxian; Bae, Hyeon-Min

    2015-11-01

    The ever-increasing demand for bandwidth triggered by mobile and video Internet traffic requires advanced interconnect solutions satisfying functional and economic constraints. A new interconnect called E-TUBE is proposed as a cost-and-power-effective all-electrical-domain wideband waveguide solution for high-speed high-volume short-reach communication links. The E-TUBE achieves an unprecedented level of performance in terms of bandwidth-per-carrier frequency, power, and density without requiring a precision manufacturing process unlike conventional optical/waveguide solutions. The E-TUBE exhibits a frequency-independent loss-profile of 4 dB/m and has nearly 20-GHz bandwidth over the V band. A single-sideband signal transmission enabled by the inherent frequency response of the E-TUBE renders two-times data throughput without any physical overhead compared to conventional radio frequency communication technologies. This new interconnect scheme would be attractive to parties interested in high throughput links, including but not limited to, 100/400 Gbps chip-to-chip communications.

  14. Changes of indicators of high-speed and high-speed and power preparedness at volleyball players of 12–13 years old

    Directory of Open Access Journals (Sweden)

    Oleg Shevchenko

    2016-04-01

    Full Text Available Purpose: to define changes of indicators of high-speed and high-speed and power preparedness of volleyball players of 12–13 years old. Material & Methods: the test exercises, which are recommended by the training program of CYSS on volleyball, were used for the definition of the level of development of high-speed and high-speed and power abilities of volleyball players. 25 young volleyball players from the group of the previous basic preparation took part in the experiment. Sports experience of sportsmen is 3–4 years. The analysis of scientifically-methodical literature, pedagogical testing, pedagogical experiment, methods of mathematical statistics were carried out. Results: the analyzed level of high-speed and high-speed and power abilities of volleyball players. Conclusions: the results had reliable changes (t=2,2–2,4 at р<0,05 of the level of high-speed and high-speed and power abilities of volleyball players of 12–13years old in the experimental group at the end of the experiment, except run on 30 m that demonstrates a positive influence of application of special exercises in the educational-training process.

  15. EFFICIENCY OF LINEAR PULSE ELECTROMECHANICAL CONVERTERS DESIGNED TO CREATE IMPACT LOADS AND HIGH SPEEDS

    Directory of Open Access Journals (Sweden)

    V.F. Bolyukh

    2015-06-01

    Full Text Available Considered linear impulse electromechanical converters (LIEC are used to create a significant impact and high-acceleration actuators on a short active site. The most effective types of LIEC are induction-dynamic (IDC, electro-dynamic (EDC and electro-magnetic (EMC converters. In all these types of short-term excitement LIEC carried briefly of the inductor from a pulsed source. This occurs when the magnetic field of the inductor causes the electro-dynamic or electromagnetic forces, leading to a linear movement of the armature. However, the issue at evaluating the effects of IDC, EDC and EMC, for creating a shock simultaneously with high speed to the specified criteria in the presence of ferromagnetic core virtually unexplored. The paper presents the simulated computer-WIDE 2D model of LIEC of coaxial configuration with ferromagnetic core by using software package COMSOL Multiphysics 4.4, taking into account the related electro-magnetic, thermal, and magnetic fields. In addition a synthesis of high-performance IDC, EDC and EMC to ensure maximum impact and speed of the operating element, whereby the comparative analysis of the effectiveness of the IDC, EDC and EMC via an integral index, taking into account the maximum value and momentum of electro-dynamic or electromagnetic force acting on the armature, maximum and average speed armature, efficiency, mass and dimensions performance transducer stray field, the maximum current density in the inductor is carried out. On the basis of the eight selection policies set the most efficient types of power and speed LIEC. It is shown that any one of the strategies IDC selection is not the best. To ensure maximum impact force is the most effective EMC and to ensure the greatest speed – EDC.

  16. Towards real-time feedback in high performance speed skating

    NARCIS (Netherlands)

    van der Eb, Jeroen; Zandee, Willem; van den Bogaard, Timo; Geraets, Sjoerd; Veeger, H.E.J.; Beek, Peter; Potthast, Wolfgang; Niehoff, Anja; David, Sina

    2017-01-01

    The aim of the current study is to evaluate several performance indicators to be used as real-time feedback in the coming experiments to enhance performance of elite speeds skaters. Six speed skaters, wearing one IMU per skate, collected data over one full training season to evaluate and pinpoint

  17. An enhanced high-speed multi-digit BCD adder using quantum-dot cellular automata

    Science.gov (United States)

    Ajitha, D.; Ramanaiah, K. V.; Sumalatha, V.

    2017-02-01

    The advent of development of high-performance, low-power digital circuits is achieved by a suitable emerging nanodevice called quantum-dot cellular automata (QCA). Even though many efficient arithmetic circuits were designed using QCA, there is still a challenge to implement high-speed circuits in an optimized manner. Among these circuits, one of the essential structures is a parallel multi-digit decimal adder unit with significant speed which is very attractive for future environments. To achieve high speed, a new correction logic formulation method is proposed for single and multi-digit BCD adder. The proposed enhanced single-digit BCD adder (ESDBA) is 26% faster than the carry flow adder (CFA)-based BCD adder. The multi-digit operations are also performed using the proposed ESDBA, which is cascaded innovatively. The enhanced multi-digit BCD adder (EMDBA) performs two 4-digit and two 8-digit BCD addition 50% faster than the CFA-based BCD adder with the nominal overhead of the area. The EMDBA performs two 4-digit BCD addition 24% faster with 23% decrease in the area, similarly for 8-digit operation the EMDBA achieves 36% increase in speed with 21% less area compared to the existing carry look ahead (CLA)-based BCD adder design. The proposed multi-digit adder produces significantly less delay of (N -1) + 3.5 clock cycles compared to the N* One digit BCD adder delay required by the conventional BCD adder method. It is observed that as per our knowledge this is the first innovative proposal for multi-digit BCD addition using QCA.

  18. Fire protection for high speed line tunnels; Risk analysis and exceptional robotic application results

    NARCIS (Netherlands)

    Linde, F.W.J. van de; Gijsbers, F.B.J.; Klok, G.J.

    2006-01-01

    The Green Hart Tunnel in The Netherlands is a 7 km long high speed railway tunnel with an exterior diameter of 14.5 metres. A separation wall devides the tunnel into two single tubes. High speed trains will pass the tunnel at speeds of more than 300 kph. Inside the tunnel 200,000 m2 fire resistant

  19. Improvement of vocal pathologies diagnosis using high-speed videolaryngoscopy.

    Science.gov (United States)

    Tsuji, Domingos Hiroshi; Hachiya, Adriana; Dajer, Maria Eugenia; Ishikawa, Camila Cristina; Takahashi, Marystella Tomoe; Montagnoli, Arlindo Neto

    2014-07-01

    Introduction The study of the dynamic properties of vocal fold vibration is important for understanding the vocal production mechanism and the impact of organic and functional changes. The advent of high-speed videolaryngoscopy (HSV) has provided the possibility of seeing the real cycle of vocal fold vibration in detail through high sampling rate of successive frames and adequate spatial resolution. Objective To describe the technique, advantages, and limitations of using HSV and digital videokymography in the diagnosis of vocal pathologies. Methods We used HSV and digital videokymography to evaluate one normophonic individual and four patients with vocal fold pathologies (nodules, unilateral paralysis of the left vocal fold, intracordal cyst, and adductor spasmodic dysphonia). The vocal fold vibration parameters (glottic closure, vibrational symmetry, periodicity, mucosal wave, amplitude, and glottal cycle phases) were assessed. Results Differences in the vocal vibration parameters were observed and correlated with the pathophysiology. Conclusion HSV is the latest diagnostic tool in visual examination of vocal behavior and has considerable potential to refine our knowledge regarding the vocal fold vibration and voice production, as well as regarding the impact of pathologic conditions have on the mechanism of phonation.

  20. Improvement of Vocal Pathologies Diagnosis Using High-Speed Videolaryngoscopy

    Directory of Open Access Journals (Sweden)

    Tsuji, Domingos Hiroshi

    2014-04-01

    Full Text Available Introduction The study of the dynamic properties of vocal fold vibration is important for understanding the vocal production mechanism and the impact of organic and functional changes. The advent of high-speed videolaryngoscopy (HSV has provided the possibility of seeing the real cycle of vocal fold vibration in detail through high sampling rate of successive frames and adequate spatial resolution. Objective To describe the technique, advantages, and limitations of using HSV and digital videokymography in the diagnosis of vocal pathologies. Methods We used HSV and digital videokymography to evaluate one normophonic individual and four patients with vocal fold pathologies (nodules, unilateral paralysis of the left vocal fold, intracordal cyst, and adductor spasmodic dysphonia. The vocal fold vibration parameters (glottic closure, vibrational symmetry, periodicity, mucosal wave, amplitude, and glottal cycle phases were assessed. Results Differences in the vocal vibration parameters were observed and correlated with the pathophysiology. Conclusion HSV is the latest diagnostic tool in visual examination of vocal behavior and has considerable potential to refine our knowledge regarding the vocal fold vibration and voice production, as well as regarding the impact of pathologic conditions have on the mechanism of phonation.

  1. Lagrangian transported MDF methods for compressible high speed flows

    Science.gov (United States)

    Gerlinger, Peter

    2017-06-01

    This paper deals with the application of thermochemical Lagrangian MDF (mass density function) methods for compressible sub- and supersonic RANS (Reynolds Averaged Navier-Stokes) simulations. A new approach to treat molecular transport is presented. This technique on the one hand ensures numerical stability of the particle solver in laminar regions of the flow field (e.g. in the viscous sublayer) and on the other hand takes differential diffusion into account. It is shown in a detailed analysis, that the new method correctly predicts first and second-order moments on the basis of conventional modeling approaches. Moreover, a number of challenges for MDF particle methods in high speed flows is discussed, e.g. high cell aspect ratio grids close to solid walls, wall heat transfer, shock resolution, and problems from statistical noise which may cause artificial shock systems in supersonic flows. A Mach 2 supersonic mixing channel with multiple shock reflection and a model rocket combustor simulation demonstrate the eligibility of this technique to practical applications. Both test cases are simulated successfully for the first time with a hybrid finite-volume (FV)/Lagrangian particle solver (PS).

  2. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.

    2014-07-01

    Full Text Available Gears are one of the most widely applied precision machine elements in power transmission systems employed in automotive, aerospace, marine, rail and industrial applications because of their reliability, precision, efficiency and versatility. Fundamentally, gears provide a very practical mechanism to transmit motion and mechanical power between two rotating shafts. However, their performance and accuracy are often hampered by tooth failure, vibrations and whine noise. This is most acute in high-speed, high power density geared rotor systems, which is the primary scope of this paper. The present study focuses on the development of a gear pair mathematical model for use to analyze the dynamics of power transmission systems. The theory includes the gear mesh representation derived from results of the quasi-static tooth contact analysis. This proposed gear mesh theory comprising of transmission error, mesh point, mesh stiffness and line-of-action nonlinear, time-varying parameters can be easily incorporated into a variety of transmission system models ranging from the lumped parameter type to detailed finite element representation. The gear dynamic analysis performed led to the discovery of the out-of-phase gear pair torsion modes that are responsible for much of the mechanical problems seen in gearing applications. The paper concludes with a discussion on effectual design approaches to minimize the influence of gear dynamics and to mitigate gear failure in practical power transmission systems.

  3. Prototype high speed optical delay line for stellar interferometry

    Science.gov (United States)

    Colavita, M. M.; Hines, B. E.; Shao, M.; Klose, G. J.; Gibson, B. V.

    1991-01-01

    The long baselines of the next-generation ground-based optical stellar interferometers require optical delay lines which can maintain nm-level path-length accuracy while moving at high speeds. NASA-JPL is currently designing delay lines to meet these requirements. The design is an enhanced version of the Mark III delay line, with the following key features: hardened, large diameter wheels, rather than recirculating ball bearings, to reduce mechanical noise; a friction-drive cart which bears the cable-dragging forces, and drives the optics cart through a force connection only; a balanced PZT assembly to enable high-bandwidth path-length control; and a precision aligned flexural suspension for the optics assembly to minimize bearing noise feedthrough. The delay line is fully programmable in position and velocity, and the system is controlled with four cascaded software feedback loops. Preliminary performance is a jitter in any 5 ms window of less than 10 nm rms for delay rates of up to 28 mm/s; total jitter is less than 10 nm rms for delay rates up to 20 mm/s.

  4. The Kaye effect revisited: High speed imaging of leaping shampoo

    Science.gov (United States)

    Versluis, Michel; Blom, Cock; van der Meer, Devaraj; van der Weele, Ko; Lohse, Detlef

    2003-11-01

    When a visco-elastic fluid such as shampoo or shower gel is poured onto a flat surface the fluid piles up forming a heap on which rather irregular combinations of fluid buckling, coiling and folding are observed. Under specific conditions a string of fluid leaps from the heap and forms a steady jet fed by the incoming stream. Momentum transfer of the incoming jet, combined with the shear-thinning properties of the fluid, lead to a spoon-like dimple in the highly viscous fluid pool in which the jet recoils. The jet can be stable for several seconds. This effect is known as the Kaye effect. In order to reveal its mechanism we analyzed leaping shampoo through high-speed imaging. We studied the jet formation, jet stability and jet disruption mechanisms. We measured the velocity of both the incoming and recoiled jet, which was found to be thicker and slower. By inclining the surface on which the fluid was poured we observed jets leaping at upto five times.

  5. Composite flywheel material design for high-speed energy storage

    Directory of Open Access Journals (Sweden)

    Michael A. Conteh

    2016-06-01

    Full Text Available Lamina and laminate mechanical properties of materials suitable for flywheel high-speed energy storage were investigated. Low density, low modulus and high strength composite material properties were implemented for the constant stress portion of the flywheel while higher density, higher modulus and strength were implemented for the constant thickness portion of the flywheel. Design and stress analysis were used to determine the maximum energy densities and shape factors for the flywheel. Analytical studies along with the use of the CADEC-online software were used to evaluate the lamina and laminate properties. This study found that a hybrid composite of M46J/epoxy–T1000G/epoxy for the flywheel exhibits a higher energy density when compared to known existing flywheel hybrid composite materials such as boron/epoxy–graphite/epoxy. Results from this study will contribute to further development of the flywheel that has recently re-emerged as a promising application for energy storage due to significant improvements in composite materials and technology.

  6. High-Speed Visualisation of Combustion in Modern Gasoline Engines

    Science.gov (United States)

    Sauter, W.; Nauwerck, A.; Han, K.-M.; Pfeil, J.; Velji, A.; Spicher, U.

    2006-07-01

    Today research and development in the field of gasoline engines have to face a double challenge: on the one hand, fuel consumption has to be reduced, while on the other hand, ever more stringent emission standards have to be fulfilled. The development of engines with its complexity of in-cylinder processes requires modern development tools to exploit the full potential in order to reduce fuel consumption. Especially optical, non-intrusive measurement techniques will help to get a better understanding of the processes. With the presented high-speed visualisation system the electromagnetic radiation from combustion in the UV range is collected by an endoscope and transmitted to a visualisation system by 10, 000 optical fibres. The signal is projected to 1, 920 photomultipliers, which convert the optical into electric signals with a maximum temporal resolution of 200 kHz. This paper shows the systematic application of flame diagnostics in modern combustion systems. For this purpose, a single-cylinder SI engine has been modified for a spray guided combustion strategy as well as for HCCI. The characteristics of flame propagation in both combustion modes were recorded and correlated with thermodynamic analyses. In case of the spray guided GDI engine, high pressure fuel injection was applied and evaluated.

  7. Materials, structures, and devices for high-speed electronics

    Science.gov (United States)

    Woollam, John A.; Snyder, Paul G.

    1992-01-01

    Advances in materials, devices, and instrumentation made under this grant began with ex-situ null ellipsometric measurements of simple dielectric films on bulk substrates. Today highly automated and rapid spectroscopic ellipsometers are used for ex-situ characterization of very complex multilayer epitaxial structures. Even more impressive is the in-situ capability, not only for characterization but also for the actual control of the growth and etching of epitaxial layers. Spectroscopic ellipsometry has expanded from the research lab to become an integral part of the production of materials and structures for state of the art high speed devices. Along the way, it has contributed much to our understanding of the growth characteristics and material properties. The following areas of research are summarized: Si3N4 on GaAs, null ellipsometry; diamondlike carbon films; variable angle spectroscopic ellipsometry (VASE) development; GaAs-AlGaAs heterostructures; Ta-Cu diffusion barrier films on GaAs; GaAs-AlGaAs superlattices and multiple quantum wells; superconductivity; in situ elevated temperature measurements of III-V's; optical constants of thermodynamically stable InGaAs; doping dependence of optical constants of GaAs; in situ ellipsometric studies of III-V epitaxial growth; photothermal spectroscopy; microellipsometry; and Si passivation and Si/SiGe strained-layer superlattices.

  8. Circuity analyses of HSR network and high-speed train paths in China

    Science.gov (United States)

    Zhao, Shuo; Huang, Jie; Shan, Xinghua

    2017-01-01

    Circuity, defined as the ratio of the shortest network distance to the Euclidean distance between one origin–destination (O-D) pair, can be adopted as a helpful evaluation method of indirect degrees of train paths. In this paper, the maximum circuity of the paths of operated trains is set to be the threshold value of the circuity of high-speed train paths. For the shortest paths of any node pairs, if their circuity is not higher than the threshold value, the paths can be regarded as the reasonable paths. With the consideration of a certain relative or absolute error, we cluster the reasonable paths on the basis of their inclusion relationship and the center path of each class represents a passenger transit corridor. We take the high-speed rail (HSR) network in China at the end of 2014 as an example, and obtain 51 passenger transit corridors, which are alternative sets of train paths. Furthermore, we analyze the circuity distribution of paths of all node pairs in the network. We find that the high circuity of train paths can be decreased with the construction of a high-speed railway line, which indicates that the structure of the HSR network in China tends to be more complete and the HSR network can make the Chinese railway network more efficient. PMID:28945757

  9. Circuity analyses of HSR network and high-speed train paths in China.

    Science.gov (United States)

    Hu, Xinlei; Zhao, Shuo; Shi, Feng; Huang, Jie; Shan, Xinghua

    2017-01-01

    Circuity, defined as the ratio of the shortest network distance to the Euclidean distance between one origin-destination (O-D) pair, can be adopted as a helpful evaluation method of indirect degrees of train paths. In this paper, the maximum circuity of the paths of operated trains is set to be the threshold value of the circuity of high-speed train paths. For the shortest paths of any node pairs, if their circuity is not higher than the threshold value, the paths can be regarded as the reasonable paths. With the consideration of a certain relative or absolute error, we cluster the reasonable paths on the basis of their inclusion relationship and the center path of each class represents a passenger transit corridor. We take the high-speed rail (HSR) network in China at the end of 2014 as an example, and obtain 51 passenger transit corridors, which are alternative sets of train paths. Furthermore, we analyze the circuity distribution of paths of all node pairs in the network. We find that the high circuity of train paths can be decreased with the construction of a high-speed railway line, which indicates that the structure of the HSR network in China tends to be more complete and the HSR network can make the Chinese railway network more efficient.

  10. Hall thruster plume measurements from High-speed Dual Langmuir Probes with Ion Saturation Reference

    Science.gov (United States)

    Sekerak, M.; McDonald, M.; Hofer, R.; Gallimore, A.

    The plasma plume of a 6 kW Hall Effect Thruster (HET) has been investigated in order to determine time-averaged and time-resolved plasma properties in a 2-D plane. HETs are steady-state devices with a multitude of kilohertz and faster plasma oscillations that are poorly understood yet impact their performance and may interact with spacecraft subsystems. HETs are known to operate in different modes with differing efficiencies and plasma characteristics, particularly the axial breathing mode and the azimuthal spoke mode. In order to investigate these phenomena, high-speed diagnostics are needed to observe time-resolved plasma properties and correlate them to thruster operating conditions. A new technique called the High-speed Dual Langmuir Probe with Ion Saturation Reference (HDLP-ISR) builds on recent results using an active and an insulated or null probe in conjunction with a third, fixed-bias electrode maintained in ion saturation for ion density measurements. The HDLP-ISR was used to measure the plume of a 6-kW-class single-channel HET called the H6 operated at 300 V and 20 A at 200 kHz. Time-averaged maps of electron density, electron temperature and plasma potential were determined in a rectangular region from the exit plane to over five channel radii downstream and from the centrally mounted cathode radially out to over three channel radii. The power spectral density (PSD) of the time-resolved plasma density oscillations showed four discrete peaks between 16 and 28 kHz which were above the broad breathing mode peak between 10 and 15 kHz. Using a high-speed camera called FastCam imaging at 87,500 frames per second, the plasma oscillations were correlated with visible rotating spokes in the discharge channel. Probes were vertically spaced in order to identify azimuthal plasma transients around the discharge channel where density delays of 14.4 μ s were observed correlating to a spoke velocity of 1800 m/s in the E× B direction. The results presented- here are

  11. Numerical study of a high-speed miniature centrifugal compressor

    Science.gov (United States)

    Li, Xiaoyi

    A miniature centrifugal compressor is a key component of reverse Brayton cycle cryogenic cooling system. The system is commonly used to generate a low cryogenic temperature environment for electronics to increase their efficiency, or generate, store and transport cryogenic liquids, such as liquid hydrogen and oxygen, where space limit is also an issue. Because of space limitation, the compressor is composed of a radial IGV, a radial impeller and an axial-direction diffuser (which reduces the radial size because of smaller diameter). As a result of reduction in size, rotating speed of the impeller is as high as 313,000 rpm, and Helium is used as the working fluid, in order to obtain the required static pressure ratio/rise. Two main characteristics of the compressor---miniature and high-speed, make it distinct from conventional compressors. Higher compressor efficiency is required to obtain a higher COP (coefficient of performance) system. Even though miniature centrifugal compressors start to draw researchers' attention in recent years, understanding of the performance and loss mechanism is still lacking. Since current experimental techniques are not advanced enough to capture details of flow at miniature scale, numerical methods dominate miniature turbomachinery study. This work numerically studied a high speed miniature centrifugal compressor with commercial CFD code. The overall performance of the compressor was predicted with consideration of interaction between blade rows by using sliding mesh model. The law of similarity of turbomachinery was validated for small scale machines. It was found that the specific ratio effect needs to be considered when similarity law is applied. But Reynolds number effect can be neglected. The loss mechanism of each component was analyzed. Loss due to turning bend was significant in each component. Tip leakage loss of small scale turbomachines has more impact on the impeller performance than that of large scale ones. Because the

  12. Evaluation of pavement skid resistance using high speed texture measurement

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2015-12-01

    Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

  13. High speed ultrasound monitoring in the field of sports biomechanics

    Science.gov (United States)

    Zakir Hossain, M.; Twerdowski, E.; Grill, W.

    2008-03-01

    Ultrasonic monitoring allowing the evaluation of the performance of muscles under training has been developed. The monitoring scheme is suitable to determine muscle movement and is based on the measurement of the transit time of longitudinally polarized ultrasound propagating across the observed muscle. Variations of the length of the muscle lead to variations of the lateral extension since the volume of the muscle is conserved. The corresponding variations of the observed time-of-flight result dominantly from the variation of the path length. This allows the time-resolved detection of the movement of the muscles in the path of the ultrasonic beam. In this way not only the degree of contraction or relaxation, but also the speed of these processes can be quantitatively monitored. The muscle thickness has been determined with a resolution of +/- 0.02 mm corresponding to about +/- 0.2 % of the thickness of the relaxed muscle. This resolution is already in the range of unavoidable uncertainties caused by the surface structure of the individual muscles. Similarly, the already obtained resolution in time corresponds to a fraction 1/750 of the time of the fastest known human muscle movement of 7.5 ms, observed for the full contraction of the eye lid muscle. The time of flight is measured along a line between two electro-acoustic transducers positioned on the skin on opposite sides of the monitored muscle. The transducers can be placed at any desired position but should be positioned such, that no bones or intestines are obstructing the path between them. The time-of-flight from which all other data is derived is observed with the aid of a computer-controlled arbitrary function generator and a synchronized transient recorder. Even in the demonstrated developmental state the equipment is already rather compact (lap-top size) and can be battery operated.

  14. A Novel High Dimensional and High Speed Data Streams Algorithm: HSDStream

    OpenAIRE

    Irshad Ahmed; Irfan Ahmed; Waseem Shahzad

    2016-01-01

    This paper presents a novel high speed clustering scheme for high-dimensional data stream. Data stream clustering has gained importance in different applications, for example, network monitoring, intrusion detection, and real-time sensing. High dimensional stream data is inherently more complex when used for clustering because the evolving nature of the stream data and high dimensionality make it non-trivial. In order to tackle this problem, projected subspace within the high dimensions and l...

  15. A comparative analysis of high speed rail station development into destination and/or multi-use facilities : the case of San Jose Diridon.

    Science.gov (United States)

    2017-02-01

    As a burgeoning literature on high-speed rail development indicates, good station-area planning is a very important prerequisite for the : eventual successful operation of a high-speed rail station; it can also trigger opportunities for economic deve...

  16. A comparative analysis of high-speed rail station development into destination and multi-use facilities : the case of San Jose Diridon.

    Science.gov (United States)

    2017-02-01

    As a burgeoning literature on high-speed rail development indicates, good station-area planning is a very important prerequisite for the eventual successful operation of a high-speed rail station; it can also trigger opportunities for economic develo...

  17. Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

    Directory of Open Access Journals (Sweden)

    Wenchuan Cai

    2014-01-01

    Full Text Available Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate the adhesion force or/and the resistance, based on which simple traction/braking control schemes are established under the consideration of actual wheel-rail adhesion condition. It is shown that the proposed controllers have simple structure and can be easily implemented from real applications. Numerical simulation also validates the effectiveness of the proposed control scheme.

  18. High-speed image processing systems in non-destructive testing

    Science.gov (United States)

    Shashev, D. V.; Shidlovskiy, S. V.

    2017-08-01

    Digital imaging systems are using in most of both industrial and scientific industries. Such systems effectively solve a wide range of tasks in the field of non-destructive testing. There are problems in digital image processing for decades associated with the speed of the operation of such systems, sufficient to efficiently process and analyze video streams in real time, ideally in mobile small-sized devices. In this paper, we consider the use of parallel-pipeline computing architectures in image processing problems using the example of an algorithm for calculating the area of an object on a binary image. The approach used allows us to achieve high-speed performance in the tasks of digital image processing.

  19. Boundary layer receptivity phenomena in three-dimensional and high-speed boundary layers

    Science.gov (United States)

    Choudhari, Meelan; Streett, Craig L.

    1990-01-01

    The process by which the boundary layer internalizes the environmental disturbances in the form of instability waves is known as the boundary-layer receptivity. The paper discusses the importance of receptivity in transition research. The receptivity scenario for three-dimensional and high-speed boundary layers is examined. It is found that, while receptivity mechanisms present in the low-speed case are also operative in these complex flows, certain uniquely 'compressible' receptivity mechanisms may come into play as well. Both numerical, and where convenient, asymptotic procedures are utilized to develop quantitative predictions of the localized generation of a variety of instability types (Tollmien-Schlichting, inflectional, higher modes, crossflow vortices) in boundary layer flows relevant to the National Aero-Space Plane (NASP).

  20. High speed low damage grinding of advanced ceramics - Phase II Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, J.A.; Malkin, S.

    2000-02-01

    In the manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. As a result, one of the most challenging tasks faced by manufacturing process engineers is the development of a ceramic finishing process to maximize part throughput while minimizing costs and associated scrap levels. The efforts summarized in this report represent the second phase of a program whose overall objective was to develop a single-step, roughing-finishing process suitable for producing high-quality silicon nitride parts at high material removal rates and at substantially lower cost than traditional, multi-stage grinding processes. More specifically, this report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding which employs elevated wheel speeds to achieve the small grain depths of cut necessary for low-damage grinding while operating at relatively high material removal rates. The study employed the combined use of laboratory grinding tests, mathematical grinding models, and characterization of the resultant surface condition. A single-step, roughing-finishing process operating at high removal rates was developed and demonstrated.