WorldWideScience

Sample records for high speed train

  1. Aerodynamics of High-Speed Trains

    Science.gov (United States)

    Schetz, Joseph A.

    This review highlights the differences between the aerodynamics of high-speed trains and other types of transportation vehicles. The emphasis is on modern, high-speed trains, including magnetic levitation (Maglev) trains. Some of the key differences are derived from the fact that trains operate near the ground or a track, have much greater length-to-diameter ratios than other vehicles, pass close to each other and to trackside structures, are more subject to crosswinds, and operate in tunnels with entry and exit events. The coverage includes experimental techniques and results and analytical and numerical methods, concentrating on the most recent information available.

  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...... in type I and II fibers did not change. CONCLUSION: In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers...

  3. 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.)

  4. Research on Aerodynamic Noise Reduction for High-Speed Trains

    OpenAIRE

    Yadong Zhang; Jiye Zhang; Tian Li; Liang Zhang; Weihua Zhang

    2016-01-01

    A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES) using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H)...

  5. Research on Aerodynamic Noise Reduction for High-Speed Trains

    OpenAIRE

    Yadong Zhang; Jiye Zhang; Tian Li; Liang Zhang; Weihua Zhang

    2016-01-01

    A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES) using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H)...

  6. 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.

  7. Research on Aerodynamic Noise Reduction for High-Speed Trains

    Directory of Open Access Journals (Sweden)

    Yadong Zhang

    2016-01-01

    Full Text Available A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD/Ffowcs Williams-Hawkings (FW-H acoustic analogy. An analysis of noise reduction methods based on the main noise sources was performed. An aerodynamic noise model for a full-scale high-speed train, including three coaches with six bogies, two inter-coach spacings, two windscreen wipers, and two pantographs, was established. Several low-noise design improvements for the high-speed train were identified, based primarily on the main noise sources; these improvements included the choice of the knuckle-downstream or knuckle-upstream pantograph orientation as well as different pantograph fairing structures, pantograph fairing installation positions, pantograph lifting configurations, inter-coach spacings, and bogie skirt boards. Based on the analysis, we designed a low-noise structure for a full-scale high-speed train with an average sound pressure level (SPL 3.2 dB(A lower than that of the original train. Thus, the noise reduction design goal was achieved. In addition, the accuracy of the aerodynamic noise calculation method was demonstrated via experimental wind tunnel tests.

  8. 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.

  9. Flow structure around high-speed train in open air

    Institute of Scientific and Technical Information of China (English)

    田红旗; 黄莎; 杨明智

    2015-01-01

    According to the analysis of the turbulent intensity level around the high-speed train, the maximum turbulent intensity ranges from 0.2 to 0.5 which belongs to high turbulent flow. The flow field distribution law was studied and eight types of flow regions were proposed. They are high pressure with air stagnant region, pressure decreasing with air accelerating region, low pressure with high air flow velocity region I, turbulent region, steady flow region, low pressure with high air flow velocity region II, pressure increasing with air decelerating region and wake region. The analysis of the vortex structure around the train shows that the vortex is mainly induced by structures with complex mutation and large curvature change. The head and rear of train, the underbody structure, the carriage connection section and the wake region are the main vortex generating sources while the train body with even cross-section has rare vortexes. The wake structure development law studied lays foundation for the train drag reduction.

  10. Research of inverse mathematical model to high-speed trains

    Institute of Scientific and Technical Information of China (English)

    朱涛; 肖守讷; 马卫华; 阳光武

    2014-01-01

    Operation safety and stability of the train mainly depend on the interaction between the wheel and rail. Knowledge of wheel/rail contact force is important for vehicle control systems that aim to enhance vehicle stability and passenger safety. Since wheel/rail contact forces of high-speed train are very difficult to measure directly, a new estimation process for wheel/rail contact forces was introduced in this work. Based on the state space equation, dynamic programming methods and the Bellman principle of optimality, the main theoretical derivation of the inversion mathematical model was given. The new method overcomes the weakness of large fluctuations which exist in current inverse techniques. High-speed vehicle was chosen as the research object, accelerations of axle box as input conditions, 10 degrees of freedom vertical vibration model and 17 degrees of freedom lateral vibration model were established, respectively. Under 250 km/h, the vertical and lateral wheel/rail forces were identified. From the time domain and frequency domain, the comparison of the results between inverse and SIMPACK models were given. The results show that the inverse mathematical model has high precision for inversing the wheel/rail contact forces of an operation high-speed vehicle.

  11. Improving the critical speeds of high-speed trains using magnetorheological technology

    Science.gov (United States)

    Sun, Shuaishuai; Deng, Huaxia; Li, Weihua; Du, Haiping; Qing Ni, Yi; Zhang, Jin; Yang, Jian

    2013-11-01

    With the rapid development of high-speed railways, vibration control for maintaining stability, passenger comfort, and safety has become an important area of research. In order to investigate the mechanism of train vibration, the critical speeds of various DOFs with respect to suspension stiffness and damping are first calculated and analyzed based on its dynamic equations. Then, the sensitivity of the critical speed is studied by analyzing the influence of different suspension parameters. On the basis of these analyses, a conclusion is drawn that secondary lateral damping is the most sensitive suspension damper. Subsequently, the secondary lateral dampers are replaced with magnetorheological fluid (MRF) dampers. Finally, a high-speed train model with MRF dampers is simulated by a combined ADAMS and MATLAB simulation and tested in a roller rig test platform to investigate the mechanism of how the MRF damper affects the train’s stability and critical speed. The results show that the semi-active suspension installed with MRF dampers substantially improves the stability and critical speed of the train.

  12. 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.

  13. 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.

  14. 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.

  15. The effect of high load training on psychomotor speed

    NARCIS (Netherlands)

    Nederhof, E.; Lemmink, K.; Zwerver, J.; Mulder, T.

    The purpose of the present study was to investigate whether overreached athletes show psychomotor slowness after a period of high load training. Fourteen well-trained cyclists (10 male, 4 female, mean age 25.3 [SD = 4.1] years, mean maximal oxygen consumption 65.5 [SD=8.1] ml/ kg-min) performed a

  16. 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.

  17. NUMERICAL AND EXPERIMENTAL INVESTIGATION OF WAVE DYNAMIC PROCESSES IN HIGH-SPEED TRAIN/TUNNELS

    Institute of Scientific and Technical Information of China (English)

    姜宗林; K.Matsuoka; A.Sasoh; K.Takayama

    2002-01-01

    Numerical and experimental investigation on wave dynamic processes induced by high-speed trains entering railway tunnels are presented. Experiments were conducted by using a 1:250 scaled train-tunnel simulator. Numerical simulations were carried out by solving the axisymmetric Euler equations with the dispersioncontrolled scheme implemented with moving boundary conditions. Pressure histories at various positions inside the train-tunnel simulator at different distance measured from the entrance of the simulator are recorded both numerically and experimentally,and then compared with each other for two train speeds. After the validation of nonlinear wave phenomena, detailed numerical simulations were then conducted to account for the generation of compression waves near the entrance, the propagation of these waves along the train tunnel, and their gradual development into a weak shock wave. Four wave dynamic processes observed are interpreted by combining numerical results with experiments. They are: high-speed trains moving over a free terrain before entering railway tunnels; the abrupt-entering of high-speed trains into railway tunnels; the abrupt-entering of the tail of high-speed trains into railway tunnels; and the interaction of compression and expansion waves ahead of high-speed trains. The effects of train-tunnel configurations, such as the train length and the train-tunnel blockage ratio, on these wave processes have been investigated as well.

  18. Sensor network architecture for intelligent high-speed train on-board monitoring

    Institute of Scientific and Technical Information of China (English)

    Xiao-fan WU; Chun CHEN; Jia-jun BU; Gang CHEN

    2011-01-01

    The China's high-speed railway is experiencing a rapid growth.Its operating mileage and the number of operating trains will exceed 45000 km and 1500 trains by 2015,respectively.During the long range and constant high-speed operation,the high-speed trains have extremely complex and varied work conditions.Such a situation creates a huge demand for high-speed train on-board monitoring.In this paper,architecture for high-speed train on-board monitoring sensor network is proposed.This architecture is designed to achieve the goals of reliable sensing,scalable data transporting,and easy management.The three design goals are realized separately.The reliable sensing is achieved by deploying redundant sensor nodes in the same components.Then a hierarchal transporting scheme is involved to meet the second goal.Finally,an electronic-tag based addressing method is introduced to solve the management problem.

  19. Pressure Distribution Characters of Flow Field around High-Speed Train

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on incompressible viscous fluid Navier-Stokes equation and k-ε 2-equationsturbulent model, an investigation on 3D turbulent flow field around four kinds of train models has been made by finite element method. From the calculation, the pressure distribution characters of flow field around high-speed trains have been obtained. It is significant for strength design of the high-speed train body, for resisting wind design of the facilities beside the high-speed railways and for determining the aerodynamic force of induced air to the human body near the railways.

  20. Dynamic analysis of a high-speed train operating on a curved track with failed fasteners

    Institute of Scientific and Technical Information of China (English)

    Li ZHOU; Zhi-yun SHEN

    2013-01-01

    A high-speed train-track coupling dynamic model is used to investigate the dynamic behavior of a high-speed train operating on a curved track with failed fasteners.The model considers a high-speed train consisting of eight vehicles coupled with a ballasted track.The vehicle is modeled as a multi-body system,and the rail is modeled with a Timoshenko beam resting on the discrete sleepers.The vehicle model considers the effect of the end connections of the neighboring vehicles on the dynamic behavior.The track model takes into account the lateral,vertical,and torsional deformations of the rails and the effect of the discrete sleeper support on the coupling dynamics of the vehicles and the track.The sleepers are assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed.The train model couples with the track model by using a Hertzian contact model for the wheel/rail normal force calculation,and the nonlinear creep theory by Shen et al.(1984) is used for wheel/rail tangent force calculation.In the analysis,a curved track of 7000-m radius with failed fasteners is selected,and the effects of train operational speed and the number of failed fasteners on the dynamic behaviors of the train and the track are investigated in detail.Furthermore,the wheel/rail forces and derailment coefficient and the wheelset loading reduction are analyzed when the high-speed train passes over the curved track with the different number of continuously failed fasteners at different operational speeds.Through the detailed numerical analysis,it is found that the high-speed train can operate normally on the curved track of 7000-m radius at the speeds of 200 km/h to 350 km/h.

  1. Fire ventilation for the high-speed line south train tunnels

    NARCIS (Netherlands)

    Leur, P.H.E. van de; Oerle, N.J. van; Lemaire, A.D.; Molag, M.

    1999-01-01

    In The Netherlands, the High-Speed Line South project currently under development as a part of the European railway network for high speed trains. In support of a Quantitative Risk Assessment, CFD calculations provide data on the consequences of fire scenarios for escaping passengers. The paper repo

  2. INVESTIGATION OF AERODYNAMIC PRESSURE DURING THE HIGH-SPEED TRAIN PASSAGE

    Directory of Open Access Journals (Sweden)

    S. T. Djabbarov

    2016-10-01

    Full Text Available Purpose. The scientific paper highlights research of aerodynamic pressure and distribution of airflow velocity field along the moving high-speed train. Methodology. The study of velocity field distribution around the moving high-speed train is produced by simulating its movement as axially symmetric body with the ogive-shaped head and tail parts in compressible (acoustic environment. Findings. The values of the absolute velocity (theoretical of air flow generated by the body movement is determined (for the case when the body moves at a constant speed (200, 250, 350, 400 km / h at a certain height from the ground, for the points located at different distances from the axis of the moving body (high-speed train. The calculations results allowed building the graphs of the air flow velocity in the acoustic environment along the moving body at different distances from it. Using the Bernoulli law (pressure change dependences on the flow velocity, the values of the overpressure generated by the air stream from the moving body were determined. Originality. This is the first theoretical study of the aerodynamics of the high-speed train as axially symmetric body with the ogive-shaped head and tail parts in compressible (acoustic environment, moving with steady speed. The research results allow us to establish the distribution of the excess air flow pressure generated along the moving high-speed train. Practical value. The obtained results allows determining of the following parameters: 1 requirements for physical-mechanical and strength characteristics of the individual elements of the railway infrastructure in the areas of high-speed train movement, subject to aerodynamic pressure; 2 minimum distance from the track safe for people location during high-speed train passage.

  3. Modeling and simulation of high-speed passenger train movements in the rail line

    Institute of Scientific and Technical Information of China (English)

    Cao Cheng-Xuan; Xu Yan; Li Ke-Ping

    2013-01-01

    In this paper,we propose a new formula of the real-time minimum safety headway based on the relative velocity of consecutive trains and present a dynamic model of high-speed passenger train movements in the rail line based on the proposed formula of the minimum safety headway.Moreover,we provide the control strategies of the high-speed passenger train operations based on the proposed formula of the real-time minimum safety headway and the dynamic model of highspeed passenger train movements.The simulation results demonstrate that the proposed control strategies of the passenger train operations can greatly reduce the delay propagation in the high-speed rail line when a random delay occurs.

  4. Field acoustic measurements of high-speed train sound along BTIR

    Science.gov (United States)

    Yu, HuaHua; Li, JiaChun

    2013-02-01

    In this paper, single-point field measurements of noise radiated from high-speed trains were performed at two sites along Beijing-Tianjin intercity railway (BTIR), aiming at acquiring the realistic acoustic data for validation and verification of physical model and computational prediction. The measurements showed that A-weighted sound pressure levels (SPLs) were between 80 and 87 dBA as trains passed. The maximum noise occurred at the moment when the pantograph arrived, suggesting that pantograph noise was one of the most significant sources. Sound radiated from high-speed trains of BTIR was a typical broadband spectrum with most acoustic power restricted in the range of medium-high frequency from about 400 Hz to 5 kHz. Aerodynamic noise was shown to be the dominant one over other acoustic sources for high-speed trains.

  5. SIMULATION STUDY OF AERODYNAMIC FORCE FOR HIGH-SPEED MAGNETICALLY-LEVITATED TRAINS

    Institute of Scientific and Technical Information of China (English)

    LI Renxian; LIU Yingqing; ZHAI Wanming

    2006-01-01

    Based on Reynolds average Navier-Storkes equations of viscous incompressible fluid and k-ε two equations turbulent model, the aerodynamic forces of high-speed magnetically-levitated(maglev) trains in transverse and longitudinal wind are investigated by finite volume method. Near 80 calculation cases for 2D transverse wind fields and 20 cases for 3D longitudinal wind fields are and lyzed. The aerodynamic side force, yawing, drag, lift and pitching moment for different types of maglev trains and a wheel/rail train are compared under the different wind speeds. The types of maglev train models for 2D transverse wind analysis included electromagnetic suspension (EMS) type train,electrodynamic suspension (EDS) type train, EMS type train with shelter wind wall in one side or two sides of guideway and the walls, which are in different height or/and different distances from train body. The situation of maglev train running on viaduct is also analyzed. For 3D longitudinal wind field analysis, the model with different sizes of air clearances beneath maglev train is examined for the different speeds. Calculation result shows that: ① Different transverse effects are shown in different types of maglev trains. ② The shelter wind wall can fairly decrease the transverse effect on the maglev train. ③ When the shelter wall height is 2 m, there is minimum side force on the train.When the shelter wall height is 2.5 m, there is minimum yawing moment on the train. ④ When the distance between inside surfaces of the walls and center of guideway is 4.0 m, there is minimum transverse influence on the train. ⑤ The size of air clearance beneath train body has a small influence on aerodynamic drag of the train, but has a fairly large effect on aerodynamic lift and pitching moment of the train. ⑥ The calculating lift and pitching moment for maglev train models are minus values.

  6. Aerodynamic simulation of high-speed trains based on the Lattice Boltzmann Method (LBM)

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Aerodynamic simulation of high-speed trains has been carried out by using Lattice Boltzmann Method (LBM). Non-simplified train model was used and the number of space grids reached tens of millions. All results under different working conditions reflected the actual situation.

  7. Moving Model Test of High-Speed Train Aerodynamic Drag Based on Stagnation Pressure Measurements.

    Science.gov (United States)

    Yang, Mingzhi; Du, Juntao; Li, Zhiwei; Huang, Sha; Zhou, Dan

    2017-01-01

    A moving model test method based on stagnation pressure measurements is proposed to measure the train aerodynamic drag coefficient. Because the front tip of a high-speed train has a high pressure area and because a stagnation point occurs in the center of this region, the pressure of the stagnation point is equal to the dynamic pressure of the sensor tube based on the obtained train velocity. The first derivation of the train velocity is taken to calculate the acceleration of the train model ejected by the moving model system without additional power. According to Newton's second law, the aerodynamic drag coefficient can be resolved through many tests at different train speeds selected within a relatively narrow range. Comparisons are conducted with wind tunnel tests and numerical simulations, and good agreement is obtained, with differences of less than 6.1%. Therefore, the moving model test method proposed in this paper is feasible and reliable.

  8. Outage Analysis of Train-to-Train Communication Model over Nakagami-m Channel in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Pengyu Liu

    2013-01-01

    Full Text Available This paper analyzes the end-to-end outage performance of high-speed-railway train-to-train communication model in high-speed railway over independent identical and nonidentical Nakagami-m channels. The train-to-train communication is inter-train communication without an aid of infrastructure (for base station. Source train uses trains on other rail tracks as relays to transmit signals to destination train on the same track. The mechanism of such communication among trains can be divided into three cases based on occurrence of possible-occurrence relay trains. We first present a new closed form for the sum of squared independent Nakagami-m variates and then derive an expression for the outage probability of the identical and non-identical Nakagami-m channels in three cases. In particular, the problem is improved by the proposed formulation that statistic for sum of squared Nakagami-m variates with identical m tends to be infinite. Numerical analysis indicates that the derived analytic results are reasonable and the outage performance is better over Nakagami-m channel in high-speed railway scenarios.

  9. Combustion performance of flame-ignited high-speed train seats via full-scale tests

    Directory of Open Access Journals (Sweden)

    Jie Zhu

    2015-10-01

    Full Text Available Determining the combustion characteristics of combustibles in high-speed trains is the foundation of evaluating the fire hazard on high-speed trains scientifically, and establishing effective active and passive fire precautions. In this study, the double seats in the compartments of CRH1 high-speed trains were used as the main research object. Under different test conditions, including the power of ignition sources and ventilation rates, full-scale furniture calorimeter tests were conducted to study important fire combustion characteristics such as the ignition characteristics of seats, heat release rate, mass loss rate, total heat release, temperature variation, and smoke release rate. The relationships among these parameters were analyzed and summarized into combustion behavior and characteristics, thus providing fundamental data and reference for the development of fire precautions and safety design of high-speed trains. The results in this test are as follows: (i The double seats of high-speed trains are relatively easy to ignite and susceptible to the fire ground environment. (ii The combustion temperature in the test apparatus exceeded 600 °C in only 2 min for the larger ignition source. (iii The heat release rate exceeded 800 kW. (iv The total heat release resulted mainly from flame combustion. (v The final mass loss rate was ∼30%. (vi The lowest light transmittance was <25%. (vii The change process of temperature with time has the same trend as the change process of heat release rate. (viii Suppressing flame combustion and controlling the smoke generated from the seat materials themselves played key roles in retarding the combustion of high-speed train seats.

  10. 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.

  11. Fuzzy Constrained Predictive Optimal Control of High Speed Train with Actuator Dynamics

    Directory of Open Access Journals (Sweden)

    Xi Wang

    2016-01-01

    Full Text Available We investigate the problem of fuzzy constrained predictive optimal control of high speed train considering the effect of actuator dynamics. The dynamics feature of the high speed train is modeled as a cascade of cars connected by flexible couplers, and the formulation is mathematically transformed into a Takagi-Sugeno (T-S fuzzy model. The goal of this study is to design a state feedback control law at each decision step to enhance safety, comfort, and energy efficiency of high speed train subject to safety constraints on the control input. Based on Lyapunov stability theory, the problem of optimizing an upper bound on the cruise control cost function subject to input constraints is reduced to a convex optimization problem involving linear matrix inequalities (LMIs. Furthermore, we analyze the influences of second-order actuator dynamics on the fuzzy constrained predictive controller, which shows risk of potentially deteriorating the overall system. Employing backstepping method, an actuator compensator is proposed to accommodate for the influence of the actuator dynamics. The experimental results show that with the proposed approach high speed train can track the desired speed, the relative coupler displacement between the neighbouring cars is stable at the equilibrium state, and the influence of actuator dynamics is reduced, which demonstrate the validity and effectiveness of the proposed approaches.

  12. A Control Simulation Method of High-Speed Trains on Railway Network with Irregular Influence

    Institute of Scientific and Technical Information of China (English)

    杨立兴; 李想; 李克平

    2011-01-01

    Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains' movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and reseheduling trains on the rail network.

  13. Surrogate Based Optimization of Aerodynamic Noise for Streamlined Shape of High Speed Trains

    Directory of Open Access Journals (Sweden)

    Zhenxu Sun

    2017-02-01

    Full Text Available Aerodynamic noise increases with the sixth power of the running speed. As the speed increases, aerodynamic noise becomes predominant and begins to be the main noise source at a certain high speed. As a result, aerodynamic noise has to be focused on when designing new high-speed trains. In order to perform the aerodynamic noise optimization, the equivalent continuous sound pressure level (SPL has been used in the present paper, which could take all of the far field observation probes into consideration. The Non-Linear Acoustics Solver (NLAS approach has been utilized for acoustic calculation. With the use of Kriging surrogate model, a multi-objective optimization of the streamlined shape of high-speed trains has been performed, which takes the noise level in the far field and the drag of the whole train as the objectives. To efficiently construct the Kriging model, the cross validation approach has been adopted. Optimization results reveal that both the equivalent continuous sound pressure level and the drag of the whole train are reduced in a certain extent.

  14. Numerical investigation of piled raft foundation in mitigating embankment vibrations induced by high-speed trains

    Institute of Scientific and Technical Information of China (English)

    付强; 刘汉龙; 丁选明; 郑长杰

    2015-01-01

    A three-dimensional dynamic finite element model of track-ballast-embankment and piled raft foundation system is established. Dynamic response of a railway embankment to a high-speed train is simulated for two cases: soft ground improved by piled raft foundation, and untreated soft ground. The obtained results are compared both in time domain and frequency domain to evaluate the effectiveness of the ground improvement in mitigating the embankment vibrations induced by high-speed trains. The results show that ground improving methods can significantly reduce the embankment vibrations at all considered train speeds(36-432 km/h). The ground response to a moving load is dictated largely by the relationship between load speed and characteristic value of wave velocities of the ground medium. At low speeds, the ground response from a moving load is essentially quasi-static. That is, the displacements fields are essential the static fields under the load simply moving with it. For the soft ground, the displacement on the ballast surface is large at all observed train speeds. For the model case where the ground is improved by piled raft foundation, the peak displacement is reduced at all considered train speeds compared with the case without ground improvement. Based on the effect of energy-dissipating of ballast-embankment-ground system with damping, the train-induced vibration waves moving in ballast and embankment are trapped and dissipated, and thus the vibration amplitudes of dynamic displacement outside the embankment are significantly reduced. But for the vibration amplitude of dynamic velocity, the vibration waves in embankment are absorbed or reflected back, and the velocity amplitudes at the ballast and embankment surface are enhanced. For the change of the vibration character of embankment and ballast, the bearing capacity and dynamic character are improved. Therefore, both of the static and dynamic displacements are reduced by ground improvement; the dynamic

  15. Numerical investigation of piled raft foundation in mitigating embankment vibrations induced by high-speed trains

    Institute of Scientific and Technical Information of China (English)

    付强; 刘汉龙; 丁选明; 郑长杰

    2015-01-01

    A three-dimensional dynamic finite element model of track-ballast-embankment and piled raft foundation system is established. Dynamic response of a railway embankment to a high-speed train is simulated for two cases: soft ground improved by piled raft foundation, and untreated soft ground. The obtained results are compared both in time domain and frequency domain to evaluate the effectiveness of the ground improvement in mitigating the embankment vibrations induced by high-speed trains. The results show that ground improving methods can significantly reduce the embankment vibrations at all considered train speeds (36− 432 km/h). The ground response to a moving load is dictated largely by the relationship between load speed and characteristic value of wave velocities of the ground medium. At low speeds, the ground response from a moving load is essentially quasi-static. That is, the displacements fields are essential the static fields under the load simply moving with it. For the soft ground, the displacement on the ballast surface is large at all observed train speeds. For the model case where the ground is improved by piled raft foundation, the peak displacement is reduced at all considered train speeds compared with the case without ground improvement. Based on the effect of energy-dissipating of ballast-embankment-ground system with damping, the train-induced vibration waves moving in ballast and embankment are trapped and dissipated, and thus the vibration amplitudes of dynamic displacement outside the embankment are significantly reduced. But for the vibration amplitude of dynamic velocity, the vibration waves in embankment are absorbed or reflected back, and the velocity amplitudes at the ballast and embankment surface are enhanced. For the change of the vibration character of embankment and ballast, the bearing capacity and dynamic character are improved. Therefore, both of the static and dynamic displacements are reduced by ground improvement; the dynamic

  16. 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.

  17. 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.

  18. Dynamic response analysis of single-span guideway caused by high speed maglev train

    OpenAIRE

    2011-01-01

    High speed maglev is one of the most important reformations in the ground transportation systems because of its no physical contact nature. This paper intends to study the dynamic response of the single-span guideway induced by moving maglev train. The dynamic model of the maglev train-guideway system is established. In this model, a maglev train consists of three vehicles and each vehicle is regarded as a multibody system with 34 degrees-of-freedom. The guideway is modeled as a simply suppor...

  19. Design of relative position sensing system for high-speed maglev train

    Institute of Scientific and Technical Information of China (English)

    Qian Cunyuan; Han Zhengzhi; Xie Weida; Shao Derong

    2008-01-01

    In the high-speed maglev system, accurate real-time information of the train position is essential for stable, safe and efficient train operation. To detect the relative position of the high-speed maglev train from a reference position, a location method based on long stator slot detection was proposed. Besides, a prototype system has been successfully developed. The hardware structure of the system, as well as its working principle was described. Moreover, a subdivision algorithm for calculating the pole location angle signal was elucidated. Experiments show that the proposed method is feasible. The technical indexes of the detection system satisfy the requirements of the vehicle operation control system. The relative position sensing system can be put into practice.

  20. Study on Evaluation Methods for Lateral Stability of High-Speed Trains

    Institute of Scientific and Technical Information of China (English)

    YAO Jianwei; SUN Lixia; HOU Fuguo

    2012-01-01

    Taking a high-speed train in China as an example,using computer simulation technology and comparing with the test data,the three current methods including linear stability analysis method,nonlinear stability analysis method and the field testing criterion are studied to evaluate stability of high-speed trains.A new stability evaluation method is proposed which can be used to evaluate lateral stability of high-speed vehicle based on the codes of UIC 515 and UIC 518.From the viewpoint of taking the most unfavorable track conditions into account and improving the safety margin,the new method uses the root mean square of bogie lateral acceleration as a criterion to evaluate the lateral stability of high-speed trains.Numerical example shows that the proposed method not only considers the forced vibration caused by track irregularities in the actual practice,but also takes the instability self-excited vibration into account,so it can realize early warning of bogie slight unstable oscillation,meanwhile the method itself does not involve complex algorithms which has the possibility of engineering applications.

  1. 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.

  2. Numerical investigation on the aerodynamic characteristics of high-speed train under turbulent crosswind

    Institute of Scientific and Technical Information of China (English)

    Mulugeta Biadgo Asress; Jelena Svorcan

    2014-01-01

    Increasing velocity combined with decreasing mass of modern high-speed trains poses a question about the influence of strong crosswinds on its aerodynamics. Strong crosswinds may affect the running stability of high-speed trains via the amplified aerodynamic forces and moments. In this study, a simulation of turbulent crosswind flows over the leading and end cars of ICE-2 high-speed train was performed at different yaw angles in static and moving ground case scenarios. Since the train aerodynamic problems are closely associated with the flows occurring around train, the flow around the train was considered as incompressible and was obtained by solving the incom-pressible form of the unsteady Reynolds-averaged Navier–Stokes (RANS) equations combined with the realizable k-epsilon turbulence model. Important aerodynamic coef-ficients such as the side force and rolling moment coeffi-cients were calculated for yaw angles ranging from-30? to 60? and compared with the results obtained from wind tunnel test. The dependence of the flow structure on yaw angle was also presented. The nature of the flow field and its structure depicted by contours of velocity magnitude and streamline patterns along the train’s cross-section were presented for different yaw angles. In addition, the pressure coefficient around the circumference of the train at dif-ferent locations along its length was computed for yaw angles of 30? and 60?. The computed aerodynamic coef-ficient outcomes using the realizable k-epsilon turbulence model were in good agreement with the wind tunnel data. Both the side force coefficient and rolling moment coeffi-cients increase steadily with yaw angle till about 50? before starting to exhibit an asymptotic behavior. Contours of velocity magnitude were also computed at different cross-sections of the train along its length for different yaw angles. The result showed that magnitude of rotating vortex in the lee ward side increased with increasing yaw angle, which

  3. Exposure to electromagnetic fields aboard high-speed electric multiple unit trains.

    Science.gov (United States)

    Niu, D; Zhu, F; Qiu, R; Niu, Q

    2016-01-01

    High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.

  4. TECHNICAL APPROACH TO THE EFFICIENCY DETERMINATION OF HIGH-SPEED TRAINS

    Directory of Open Access Journals (Sweden)

    A. V. Momot

    2013-11-01

    Full Text Available Purpose. The aim of this article is to develop an approach and formulate arrangements concerning the definition of the economic appropriateness of high-speed movement implementation in Ukraine. Methodology. The economic feasibility for appropriateness of high-speed movement organization in Ukraine is an investment project, which involves step-by-step money investment into the construction. It will let get an annual profits from the passenger carriage. To solve such problems we use net present value, which UZ or newly created companies can get during the project realization and after its completion. Findings. Obtained studies can state the fact that the technical approach for full effectiveness definition of a construction and high-speed passenger trains service taking into account the cost of infrastructure, rolling stock, the impact of environmental factors, etc. was determined. Originality. We propose a scientific approach to determine the economic effectiveness of the construction and high-speed main lines service. It includes improved principles of defining the passenger traffic, the cost of high-speed rails construction, the number of rolling stock; optimizes income and expenditure calculations in the context of competitive advantages and the external factors impact on the company. A technical approach for the calculation of future traffic volumes along the high-speed line was improved. It differs essentially from the European one proposed by the French firm «SYSTRA», as it allows taking into account additional transit traffic through Ukraine. It helps to distribute the passengers on separate sections proportionally to the number of cities population, which are combined by high-speed main line, subject to the average population mobility, travel time and the coefficient that takes into account the frequency of additional passenger trips on a given section, depending on the purpose (business trip, transfer to a plane, recreation, etc

  5. Investigation of the effects of sleeper-passing impacts on the high-speed train

    Science.gov (United States)

    Wu, Xingwen; Cai, Wubin; Chi, Maoru; Wei, Lai; Shi, Huailong; Zhu, Minhao

    2015-12-01

    The sleeper-passing impact has always been considered negligible in normal conditions, while the experimental data obtained from a High-speed train in a cold weather expressed significant sleeper-passing impacts on the axle box, bogie frame and car body. Therefore, in this study, a vertical coupled vehicle/track dynamic model was developed to investigate the sleeper-passing impacts and its effects on the dynamic performance of the high-speed train. In the model, the dynamic model of vehicle is established with 10 degrees of freedom. The track model is formulated with two rails supported on the discrete supports through the finite element method. The contact forces between the wheel and rail are estimated using the non-linear Hertz contact theory. The parametric studies are conducted to analyse effects of both the vehicle speeds and the discrete support stiffness on the sleeper-passing impacts. The results show that the sleeper-passing impacts become extremely significant with the increased support stiffness of track, especially when the frequencies of sleeper-passing impacts approach to the resonance frequencies of wheel/track system. The damping of primary suspension can effectively lower the magnitude of impacts in the resonance speed ranges, but has little effect on other speed ranges. Finally, a more comprehensively coupled vehicle/track dynamic model integrating with a flexible wheel set is developed to discuss the sleeper-passing-induced flexible vibration of wheel set.

  6. Traction electrification system planning for California high-speed train project

    Energy Technology Data Exchange (ETDEWEB)

    Schmedes, Richard [Parsons Brinckerhoff, Inc., San Francisco, CA (United States). Transit and Railway Div.

    2011-04-15

    The California High-Speed Train Project will be a $ 43 Billion dedicated 1 300 km (800 miles) system and will connect California's major metropolitan centers with completely new dedicated tracks and infrastructure which will support train operations at up to 400 km/h (250 mph). It will be electrified with a 2 AC 25 kV autotransformer configuration with 50 km (30 miles) spacing between utility connections. The planning of 115 kV and 230 kV connections involves coordination with four utility companies and completion of five-year permitting and planning processes by 2016. (orig.)

  7. Rail temperature rise characteristics caused by linear eddy current brake of high-speed train

    Directory of Open Access Journals (Sweden)

    Xiaoshan Lu

    2014-12-01

    Full Text Available The rail temperature rises when the linear eddy current brake of high-speed train is working, which may lead to a change of rail physical characteristics or an effect on train operations. Therefore, a study concerning the characteristics of rail temperature rise caused by eddy current has its practical necessity. In the research, the working principle of a linear eddy current brake is introduced and its FEA model is established. According to the generation mechanism of eddy current, the theoretical formula of the internal energy which is produced by the eddy current is deduced and the thermal load on the rail is obtained. ANSYS is used to simulate the rail temperature changes under different conditions of thermal loads. The research result shows the main factors which contribute to the rising of rail temperature are the train speed, brake gap and exciting current. The rail temperature rises non-linearly with the increase of train speed. The rail temperature rise curve is more sensitive to the exciting current than the air gap. Moreover, the difference stimulated by temperature rising between rails of 60 kg/m and 75 kg/m is presented as well.

  8. High-Speed Train Stop-Schedule Optimization Based on Passenger Travel Convenience

    Directory of Open Access Journals (Sweden)

    Dingjun Chen

    2016-01-01

    Full Text Available The stop-schedules for passenger trains are important to the operation planning of high-speed trains, and they decide the quality of passenger service and the transportation efficiency. This paper analyzes the specific manifestation of passenger travel convenience and proposes the concepts of interstation accessibility and degree of accessibility. In consideration of both the economic benefits of railway corporations and the travel convenience of passengers, a multitarget optimization model is established. The model aims at minimizing stop cost and maximizing passenger travel convenience. Several constraints are applied to the model establishment, including the number of stops made by individual trains, the frequency of train service received by each station, the operation section, and the 0-1 variable. A hybrid genetic algorithm is designed to solve the model. Both the model and the algorithm are validated through case study.

  9. Muscle performance and functional capacity retention in older women after high-speed power training cessation.

    Science.gov (United States)

    Pereira, Ana; Izquierdo, Mikel; Silva, António J; Costa, Aldo M; González-Badillo, Juan José; Marques, Mário C

    2012-08-01

    Power declines more steeply than strength with advancing age and training cessation among older women and is associated with the loss of functional ability. We tested the hypothesis that the impact of 6 weeks of detraining (DT) subsequent to 12 weeks of high-speed power training on maximal strength (1RM) of the arm and leg muscles, power performance (counter movement jump and ball throwing) and functional task (sit-to-stand test) would decrease physical performance, and specifically power performance. Thirty-seven older women were divided into an experimental group and a control group [EG, n=20, 65.8 (2.5) years; CG: n=17, 64.8 (2.8) years]. Muscular strength, power and functional testings were conducted before the initiation of training (T1), after 12 weeks (T2) and after 6 weeks of DT (T3). During the 12 weeks of training, EG significantly increased their dynamic strength performance (range from 41.9 to 64.1%), muscle power output (range from 18.2 to 33.6%) (pmuscles than in muscle power (2-4.5%) and function (2.8%) (pmuscle strength than in power output and preserved physical independence, mediated in part, by the effectiveness of high-speed power training particularly developed for older women. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. The response of a high-speed train wheel to a harmonic wheel-rail force

    Science.gov (United States)

    Sheng, Xiaozhen; Liu, Yuxia; Zhou, Xin

    2016-09-01

    The maximum speed of China's high-speed trains currently is 300km/h and expected to increase to 350-400km/h. As a wheel travels along the rail at such a high speed, it is subject to a force rotating at the same speed along its periphery. This fast moving force contains not only the axle load component, but also many components of high frequencies generated from wheel-rail interactions. Rotation of the wheel also introduces centrifugal and gyroscopic effects. How the wheel responds is fundamental to many issues, including wheel-rail contact, traction, wear and noise. In this paper, by making use of its axial symmetry, a special finite element scheme is developed for responses of a train wheel subject to a vertical and harmonic wheel-rail force. This FE scheme only requires a 2D mesh over a cross-section containing the wheel axis but includes all the effects induced by wheel rotation. Nodal displacements, as a periodic function of the cross-section angle 6, can be decomposed, using Fourier series, into a number of components at different circumferential orders. The derived FE equation is solved for each circumferential order. The sum of responses at all circumferential orders gives the actual response of the wheel.

  11. Experimental investigation by laser ultrasonics for high speed train axle diagnostics.

    Science.gov (United States)

    Cavuto, A; Martarelli, M; Pandarese, G; Revel, G M; Tomasini, E P

    2015-01-01

    The present paper demonstrates the applicability of a laser-ultrasonic procedure to improve the performances of train axle ultrasonic inspection. The method exploits an air-coupled ultrasonic probe that detects the ultrasonic waves generated by a high-power pulsed laser. As a result, the measurement chain is completely non-contact, from generation to detection, this making it possible to considerably speed up inspection time and make the set-up more flexible. The main advantage of the technique developed is that it works in thermo-elastic regime and it therefore can be considered as a non-destructive method. The laser-ultrasonic procedure investigated has been applied for the inspection of a real high speed train axle provided by the Italian railway company (Trenitalia), on which typical fatigue defects have been expressly created according to standard specifications. A dedicated test bench has been developed so as to rotate the axle with the angle control and to speed up the inspection of the axle surface. The laser-ultrasonic procedure proposed can be automated and is potentially suitable for regular inspection of train axles. The main achievements of the activity described in this paper are: – the study of the effective applicability of laser-ultrasonics for the diagnostic of train hollow axles with variable sections by means of a numerical FE model, – the carrying out of an automated experiment on a real train axle, – the analysis of the sensitivity to experimental parameters, like laser source – receiving probe distance and receiving probe angular position, – the demonstration that the technique is suitable for the detection of surface defects purposely created on the train axle. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Control of interior surface materials for speech privacy in high-speed train cabins.

    Science.gov (United States)

    Jang, H S; Lim, H; Jeon, J Y

    2017-05-01

    The effect of interior materials with various absorption coefficients on speech privacy was investigated in a 1:10 scale model of one high-speed train cabin geometry. The speech transmission index (STI) and privacy distance (rP ) were measured in the train cabin to quantify speech privacy. Measurement cases were selected for the ceiling, sidewall, and front and back walls and were classified as high-, medium- and low-absorption coefficient cases. Interior materials with high absorption coefficients yielded a low rP , and the ceiling had the largest impact on both the STI and rP among the interior elements. Combinations of the three cases were measured, and the maximum reduction in rP by the absorptive surfaces was 2.4 m, which exceeds the space between two rows of chairs in the high-speed train. Additionally, the contribution of the interior elements to speech privacy was analyzed using recorded impulse responses and a multiple regression model for rP using the equivalent absorption area. The analysis confirmed that the ceiling was the most important interior element for improving speech privacy. These results can be used to find the relative decrease in rP in the acoustic design of interior materials to improve speech privacy in train cabins. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Innovation Analysis Approach to Design Parameters of High Speed Train Carriage and Their Intrinsic Complexity Relationships

    Science.gov (United States)

    Xiao, Shou-Ne; Wang, Ming-Meng; Hu, Guang-Zhong; Yang, Guang-Wu

    2017-09-01

    In view of the problem that it's difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out-in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary conditions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the application of forward design method to high-speed trains.

  14. Analysis theory of spatial vibration of high-speed train and slab track system

    Institute of Scientific and Technical Information of China (English)

    XIANG Jun; HE Dan; ZENG Qing-yuan

    2008-01-01

    The motor and trailer cars of a high-speed train were modeled as a multi-rigid body system with two suspensions. According to structural characteristic of a slab track, a new spatial vibration model of track segment element of the slab track was put forward. The spatial vibration equation set of the high-speed train and slab track system was then established on the basis of the principle of total potential energy with stationary value in elastic system dynarrties and the rule of "set-in-right-position" for formulating system matrices. The equation set was solved by the Wilson-0 direct integration method. The contents mentioned above constitute the analysis theory of spatial vibration of high-speed train and slab track system. The theory was then verified by the high-speed running experiment carried out on the slab track in the Qinghuangdao-Shenyang passenger transport line. The results show that the calculated results agree well with the measured results, such as the calculated lateral and vertical rail displacements are0.82 mm and 0.9 mm and the measured ones 0.75 mm and 0.93 mm, respectively; the calculated lateral and vertical wheel-rail forcesare 8.9 kN and 102.3 kN and the measured ones 8.6 kN and 80.2 kN, respectively. The interpolation method, that is, the lateral finitestrip and slab segment element, for slab deformation proposed is of simplification and applicability compared with the traditionalplate element method. All of these demonstrate the reliability of the theory proposed.

  15. High-Speed Imaging Analysis of Register Transitions in Classically and Jazz-Trained Male Voices.

    Science.gov (United States)

    Dippold, Sebastian; Voigt, Daniel; Richter, Bernhard; Echternach, Matthias

    2015-01-01

    Little data are available concerning register functions in different styles of singing such as classically or jazz-trained voices. Differences between registers seem to be much more audible in jazz singing than classical singing, and so we hypothesized that classically trained singers exhibit a smoother register transition, stemming from more regular vocal fold oscillation patterns. High-speed digital imaging (HSDI) was used for 19 male singers (10 jazz-trained singers, 9 classically trained) who performed a glissando from modal to falsetto register across the register transition. Vocal fold oscillation patterns were analyzed in terms of different parameters of regularity such as relative average perturbation (RAP), correlation dimension (D2) and shimmer. HSDI observations showed more regular vocal fold oscillation patterns during the register transition for the classically trained singers. Additionally, the RAP and D2 values were generally lower and more consistent for the classically trained singers compared to the jazz singers. However, intergroup comparisons showed no statistically significant differences. Some of our results may support the hypothesis that classically trained singers exhibit a smoother register transition from modal to falsetto register. © 2015 S. Karger AG, Basel.

  16. Component-based model to predict aerodynamic noise from high-speed train pantographs

    Science.gov (United States)

    Latorre Iglesias, E.; Thompson, D. J.; Smith, M. G.

    2017-04-01

    At typical speeds of modern high-speed trains the aerodynamic noise produced by the airflow over the pantograph is a significant source of noise. Although numerical models can be used to predict this they are still very computationally intensive. A semi-empirical component-based prediction model is proposed to predict the aerodynamic noise from train pantographs. The pantograph is approximated as an assembly of cylinders and bars with particular cross-sections. An empirical database is used to obtain the coefficients of the model to account for various factors: incident flow speed, diameter, cross-sectional shape, yaw angle, rounded edges, length-to-width ratio, incoming turbulence and directivity. The overall noise from the pantograph is obtained as the incoherent sum of the predicted noise from the different pantograph struts. The model is validated using available wind tunnel noise measurements of two full-size pantographs. The results show the potential of the semi-empirical model to be used as a rapid tool to predict aerodynamic noise from train pantographs.

  17. High-speed pulse train amplification in semiconductor optical amplifiers with optimized bias current.

    Science.gov (United States)

    Xia, Mingjun; Ghafouri-Shiraz, H; Hou, Lianping; Kelly, Anthony E

    2017-02-01

    In this paper, we have experimentally investigated the optimized bias current of semiconductor optical amplifiers (SOAs) to achieve high-speed input pulse train amplification with high gain and low distortion. Variations of the amplified output pulse duration with the amplifier bias currents have been analyzed and, compared to the input pulse duration, the amplified output pulse duration is broadened. As the SOA bias current decreases from the high level (larger than the saturated bias current) to the low level, the broadened pulse duration of the amplified output pulse initially decreases slowly and then rapidly. Based on the analysis, an optimized bias current of SOA for high-speed pulse train amplification is introduced. The relation between the SOA optimized bias current and the parameters of the input pulse train (pulse duration, power, and repetition rate) are experimentally studied. It is found that the larger the input pulse duration, the lower the input pulse power or a higher repetition rate can lead to a larger SOA optimized bias current, which corresponds to a larger optimized SOA gain. The effects of assist light injection and different amplifier temperatures on the SOA optimized bias current are studied and it is found that assist light injection can effectively increase the SOA optimized bias current while SOA has a lower optimized bias current at the temperature 20°C than that at other temperatures.

  18. 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.

  19. Numerical investigation on the aerodynamics of a simplified high-speed train under crosswinds

    Directory of Open Access Journals (Sweden)

    Yueqing Zhuang

    2015-08-01

    Full Text Available The yaw effect of the side flow around a high-speed train is studied by means of large eddy simulation at two typical yaw angles of φ=30° and 60°, respectively. Both the mean and fluctuating values of lift force and side force coefficients increase obviously as the yaw angle increases. The spectral analysis indicates that the time-dependent aerodynamic forces are dominated by several energetic frequencies and the frequency range is broadened to a higher extent for the large yaw angle. To have a better understanding of the train aerodynamic behaviors, the dedicate three-dimensional vortical structures are analyzed for the flow at the two yaw angles. Moreover, the time-averaged flow patterns, turbulent statistics and the surface forces are also studied on sectional planes along the train.

  20. Adjustments with running speed reveal neuromuscular adaptations during landing associated with high mileage running training.

    Science.gov (United States)

    Verheul, Jasper; Clansey, Adam C; Lake, Mark J

    2016-12-08

    It remains to be determined whether running training influences the amplitude of lower limb muscle activations prior to and during the first half of stance, and whether such changes are associated with joint stiffness regulation and usage of stored energy from tendons. Therefore, the aim of this study was to investigate neuromuscular and movement adaptations before and during landing in response to running training across a range of speeds. Two groups of high mileage (HM; >45 km/wk, n=13) and low mileage (LM; muscular activations before landing. Estimated elastic work about the ankle was found to be higher in the HM runners which might play a role in reducing weight acceptance phase muscle activation levels and improve muscle activation efficiency with running training.

  1. Mass splitting of train wheels in the numerical analysis of high speed train-track interactions

    Science.gov (United States)

    Dyniewicz, Bartłomiej; Bajer, Czesław I.; Matej, Jan

    2015-01-01

    We demonstrate that the dynamic simulation of a vehicle moving on a track requires the correct mass distribution in the wheel-rail system. A wheel travelling on a rail should be modelled as a pair of masses coupled as a double mass oscillator. One of the masses is attached to the rail and carries the moving inertial load, while the second one is treated classically, being connected to the rail only through an elastic spring. This model is called the 'mass splitting model'. The classical approach overestimates the accelerations by a factor of 10. The presented method produces displacements and velocities which agree well with the results of a precise finite element method and with measurements. Some real-life problems of a vehicle moving on a track at high speed are solved numerically by own computer program and the results are compared with measurements and with the solutions obtained using other codes.

  2. Multi-Directional Sprint Training Improves Change-Of-Direction Speed and Reactive Agility in Young Highly Trained Soccer Players

    Science.gov (United States)

    Born, Dennis-Peter; Zinner, Christoph; Düking, Peter; Sperlich, Billy

    2016-01-01

    The aim of this study was to evaluate the effect of a repeated sprint training with multi-directional change-of-direction (COD) movements (RSmulti) compared to repeated shuttle sprints (RSS) on variables related to COD speed and reactive agility. Nineteen highly-trained male U15 soccer players were assigned into two groups performing either RSmulti or RSS. For both groups, each training session involved 20 repeated 15 s sprints interspersed with 30 s recovery. With RSmulti the COD movements were randomized and performed in response to a visual stimulus, while the RSS involved predefined 180° COD movements. Before and following the six training sessions, performance in the Illinois agility test (IAT), COD speed in response to a visual stimulus, 20 m linear sprint time and vertical jumping height were assessed. Both groups improved their performance in the IAT (p sprint time (P=0.73, ES = 0.07; p = 0.14, ES = 0.28) or vertical jumping height (p = 0.46, ES = 0.11; p = 0.29, ES = 0.12) for the RSmulti and RSS, respectively. In conclusion, performance in the IAT improved with the RSmulti as well as RSS. With the RSmulti however, the COD movements are performed in response to a visual stimulus, which may result in specific adaptations that improve COD speed and reactive agility in young highly trained soccer players. Key points During soccer, the players perform repeated sprints involving multi-directional COD movements, while most of these turns and twists are not pre-planned but executed in response to an external stimulus, such as ball movement, several interacting opponents and changing game situations. Both groups improved performance in the IAT. With the RSmulti on the Speedcourt however, the COD movements are performed in response to a visual stimulus, which may result in specific adaptations that improve COD speed and reactive agility. The Speedcourt could serve as a valuable method to design and individualize specific conditioning drills for young highly-trained

  3. Design and analysis of the hybrid excitation rail eddy brake system of high-speed trains

    Institute of Scientific and Technical Information of China (English)

    Ji-en MA; Bin ZHANG; Xiao-yan HUANG; You-tong FANG; Wen-ping CAO

    2011-01-01

    Compared to the current eddy braking patterns using a single magnetic source,hybrid excitation rail eddy brakes have many advantages,such as controllability,energy saving,and various operating models.Considering the large braking power consumption of the high-speed train,a hybrid excitation rail eddy brake system,which is based on the principle of electromagnetic field,is proposed to fulfill the needs of safety and reliability.Then the working processes of the mechanical lifting system and electromagnetic system are demonstrated.With the electromagnetic system analyzed using the finite element method,the factors such as speed,air gap,and exciting current have influences on the braking force and attractive force.At last,the structure optimization of the brake system is discussed.

  4. Aerodynamic modeling and stability analysis of a high-speed train under strong rain and crosswind conditions

    Institute of Scientific and Technical Information of China (English)

    Xue-ming SHAO; Jun WAN; Da-wei CHEN; Hong-bing XIONG

    2011-01-01

    With the development of high-speed train,it is considerably concerned about the aerodynamic characteristics and operation safety issues of the high-speed train under extreme weather conditions.The aerodynamic performance of a high-speed train under heavy rain and strong crosswind conditions are modeled using the Eulerian two-phase model in this paper.The impact of heavy rainfall on train aerodynamics is investigated,coupling heavy rain and a strong crosswind.Results show that the lift force,side force,and rolling moment of the train increase significantly with wind speed up to 40 m/s under a rainfall rate of 60 mm/h.when considering the rain and wind conditions.The increases of the lift force,side force,and rolling moment may deteriorate the train operating safety and cause the train to overturn.A quasi-static stability analysis based on the moment balance is used to determine the limit safety speed of a train under different rain and wind levels.The results can provide a frame of reference for the train safe operation under strong rain and crosswind conditions.

  5. A SVM framework for fault detection of the braking system in a high speed train

    Science.gov (United States)

    Liu, Jie; Li, Yan-Fu; Zio, Enrico

    2017-03-01

    In April 2015, the number of operating High Speed Trains (HSTs) in the world has reached 3603. An efficient, effective and very reliable braking system is evidently very critical for trains running at a speed around 300 km/h. Failure of a highly reliable braking system is a rare event and, consequently, informative recorded data on fault conditions are scarce. This renders the fault detection problem a classification problem with highly unbalanced data. In this paper, a Support Vector Machine (SVM) framework, including feature selection, feature vector selection, model construction and decision boundary optimization, is proposed for tackling this problem. Feature vector selection can largely reduce the data size and, thus, the computational burden. The constructed model is a modified version of the least square SVM, in which a higher cost is assigned to the error of classification of faulty conditions than the error of classification of normal conditions. The proposed framework is successfully validated on a number of public unbalanced datasets. Then, it is applied for the fault detection of braking systems in HST: in comparison with several SVM approaches for unbalanced datasets, the proposed framework gives better results.

  6. Optimization of the head shape of the CRH3 high speed train

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Aiming at optimizing the head shape of the CRH3 high speed train, an efficient optimization approach is proposed. The CFD analysis by solving Navier-Stokes equations is coupled with optimization calculation based on the multi-objective genetic algorithm, meanwhile the arbitrary shape deformation technique (ASD) is also introduced into the design flow, which greatly shortens the time consumption for geometry regeneration and flow field remeshing. As a result, the efficiency of the optimization calculation is highly improved. Statistical analysis is done to the designs in the design space, and the correlation between the design variables and the objective is studied to find out the key variables that most affect the objective. Response surface analysis is also performed to get the nonlinear relationship between the key design variables and the objective with the Kriging algorithm. Finally, after the optimization, an aerodynamic performance comparison between the optimal shape and the original shape reveals that the original shape of CRH3 high speed train owns a very stable aerodynamic performance and can be trustingly used in industry.

  7. Energy-efficient two-hop LTE resource allocation in high speed trains with moving relays

    KAUST Repository

    Alsharoa, Ahmad M.

    2014-05-01

    High-speed railway system equipped with moving relay stations placed on the middle of the ceiling of each train wagon is investigated. The users inside the train are served in two hops via the 3GPP Long Term Evolution (LTE) technology. The objective of this work is to maximize the number of served users by respecting a specific quality-of-service constraint while minimizing the total power consumption of the eNodeB and the moving relays. We propose an efficient algorithm based on the Hungarian method to find the optimal resource allocation over the LTE resource blocks in order to serve the maximum number of users with the minimum power consumption. Moreover, we derive a closed-form expression for the power allocation problem. Our simulation results illustrate the performance of the proposed scheme and compare it with various previously developed algorithms as well as with the direct transmission scenario. © 2014 IFIP.

  8. Accumulative deformation in railway track induced by high-speed traffic loading of the trains

    Institute of Scientific and Technical Information of China (English)

    Bian Xuecheng; Jiang Hongguang; Chen Yunmin

    2010-01-01

    Prediction and control of the permanent settlement of a track caused by traffic loading from trains is crucial to high-speed railway design and maintenance. In this study, a unified prediction model of accumulative deformation of geomaterials used in railway construction subjected to cyclic loadings is introduced and calibrated using physical model testing. Based on this versatile model, a calculation approach to determine the track structure settlement under repeated loadings caused by the movement of the wheel axle of the train is proposed. Regression analysis on the physical model testing is adopted to determine the parameters involved in the computational approach. Comparison of model test data and computed results shows that the parameters obtained from the back-analysis are consistent throughout the various testing conditions, and the proposed calculation approach is capable of satisfactorily predicting the accumulative settlement of the railway roadbed and subgrade soil for various axle loads and loading cycles. A case study of a high-speed railway is performed to demonstrate the feasibility of the proposed approach in realistic engineering applications. The computation results from the settlement development of a roadbed and subgrade soil are presented and discussed.

  9. Numerical analysis of the slipstream development around a high-speed train in a double-track tunnel.

    Science.gov (United States)

    Fu, Min; Li, Peng; Liang, Xi-Feng

    2017-01-01

    Analysis of the slipstream development around the high-speed trains in tunnels would provide references for assessing the transient gust loads on trackside workers and trackside furniture in tunnels. This paper focuses on the computational analysis of the slipstream caused by high-speed trains passing through double-track tunnels with a cross-sectional area of 100 m2. Three-dimensional unsteady compressible Reynolds-averaged Navier-Stokes equations and a realizable k-ε turbulence model were used to describe the airflow characteristics around a high-speed train in the tunnel. The moving boundary problem was treated using the sliding mesh technology. Three cases were simulated in this paper, including two tunnel lengths and two different configurations of the train. The train speed in these three cases was 250 km/h. The accuracy of the numerical method was validated by the experimental data from full-scale tests, and reasonable consistency was obtained. The results show that the flow field around the high-speed trains can be divided into three distinct regions: the region in front of the train nose, the annular region and the wake region. The slipstream development along the two sides of train is not in balance and offsets to the narrow side in the double-track tunnels. Due to the piston effect, the slipstream has a larger peak value in the tunnel than in open air. The tunnel length, train length and length ratio affect the slipstream velocities; in particular, the velocities increase with longer trains. Moreover, the propagation of pressure waves also induces the slipstream fluctuations: substantial velocity fluctuations mainly occur in front of the train, and weaken with the decrease in amplitude of the pressure wave.

  10. The pulsed linear induction motor concept for high-speed trains

    Energy Technology Data Exchange (ETDEWEB)

    Turman, B.N.; Marder, B.M.; Rohwein, G.J.; Aeschliman, D.P.; Kelley, J.B.; Cowan, M.; Zimmerman, R.M.

    1995-06-01

    The SERAPBIM (SEgmented RAil PHased Induction Motor) concept is a linear induction motor concept which uses rapidly-pulsed magnetic fields and a segmented reaction rail, as opposed to low-frequency fields and continuous reaction rails found in conventional linear induction motors. These improvements give a high-traction, compact, and efficient linear motor that has potential for advanced high speed rail propulsion. In the SERAPBIM concept, coils on the vehicle push against a segmented aluminum rail, which is mounted on the road bed. Current is pulsed as the coils cross an edge of the segmented rail, inducing surface currents which repel the coil. The coils must be pulsed in synchronization with the movement by reaction rail segments. This is provided by a sense-and-fire circuit that controls the pulsing of the power modulators. Experiments were conducted to demonstrate the feasibility of the pulsed induction motor and to collect data that could be used for scaling calculations. A 14.4 kg aluminum plate was accelerated down a 4 m track to speeds of over 15 m/sec with peak thrust up to 18 kN per coilset. For a trainset capable of 200 mph speed, the SERAPHIM concept design is based on coils which are each capable of producing up to 3.5 kN thrust, and 30 coil pairs are mounted on each power car. Two power cars, one at each end of the train, provide 6 MW from two gas turbine prime power units. The thrust is about 210.000 N and is essentially constant up to 200 km/hr since wheel slippage does not limit thrust as with conventional wheeled propulsion. A key component of the SERAPHIM concept is the use of passive wheel-on-rah support for the high speed vehicle. Standard steel wheels are capable of handling over 200 mph. The SERAPHIM cost is comparable to that for steel-wheel high-speed rail, and about 10% to 25% of the projected costs for a comparable Maglev system.

  11. Design of a Fatigue Detection System for High-Speed Trains Based on Driver Vigilance Using a Wireless Wearable EEG

    Science.gov (United States)

    Zhang, Xiaoliang; Li, Jiali; Liu, Yugang; Zhang, Zutao; Wang, Zhuojun; Luo, Dianyuan; Zhou, Xiang; Zhu, Miankuan; Salman, Waleed; Hu, Guangdi; Wang, Chunbai

    2017-01-01

    The vigilance of the driver is important for railway safety, despite not being included in the safety management system (SMS) for high-speed train safety. In this paper, a novel fatigue detection system for high-speed train safety based on monitoring train driver vigilance using a wireless wearable electroencephalograph (EEG) is presented. This system is designed to detect whether the driver is drowsiness. The proposed system consists of three main parts: (1) a wireless wearable EEG collection; (2) train driver vigilance detection; and (3) early warning device for train driver. In the first part, an 8-channel wireless wearable brain-computer interface (BCI) device acquires the locomotive driver’s brain EEG signal comfortably under high-speed train-driving conditions. The recorded data are transmitted to a personal computer (PC) via Bluetooth. In the second step, a support vector machine (SVM) classification algorithm is implemented to determine the vigilance level using the Fast Fourier transform (FFT) to extract the EEG power spectrum density (PSD). In addition, an early warning device begins to work if fatigue is detected. The simulation and test results demonstrate the feasibility of the proposed fatigue detection system for high-speed train safety. PMID:28257073

  12. Design of a Fatigue Detection System for High-Speed Trains Based on Driver Vigilance Using a Wireless Wearable EEG

    Directory of Open Access Journals (Sweden)

    Xiaoliang Zhang

    2017-03-01

    Full Text Available The vigilance of the driver is important for railway safety, despite not being included in the safety management system (SMS for high-speed train safety. In this paper, a novel fatigue detection system for high-speed train safety based on monitoring train driver vigilance using a wireless wearable electroencephalograph (EEG is presented. This system is designed to detect whether the driver is drowsiness. The proposed system consists of three main parts: (1 a wireless wearable EEG collection; (2 train driver vigilance detection; and (3 early warning device for train driver. In the first part, an 8-channel wireless wearable brain-computer interface (BCI device acquires the locomotive driver’s brain EEG signal comfortably under high-speed train-driving conditions. The recorded data are transmitted to a personal computer (PC via Bluetooth. In the second step, a support vector machine (SVM classification algorithm is implemented to determine the vigilance level using the Fast Fourier transform (FFT to extract the EEG power spectrum density (PSD. In addition, an early warning device begins to work if fatigue is detected. The simulation and test results demonstrate the feasibility of the proposed fatigue detection system for high-speed train safety.

  13. Wear characteristics and prediction of wheel profiles in high-speed trains

    Institute of Scientific and Technical Information of China (English)

    韩鹏; 张卫华; 李艳

    2015-01-01

    Wheel/rail relationship is a fundamental problem of railway system. Wear of wheel profiles has great effect on vehicle performance. Thus, it is important not just for the analysis of wear characteristics but for its prediction. Actual wheel profiles of the high-speed trains on service were measured in the high-speed line and the wear characteristics were analyzed which came to the following results. The wear location was centralized from−15 mm to 25 mm. The maximum wear value appeared at the area of 5 mm from tread center far from wheel flange and it was less than 1.5 mm. Then, wheel wear was fitted to get the polynomial functions on different locations and operation mileages. A binary numerical prediction model was raised to predict wheel wear. The prediction model was proved by vehicle system dynamics and wheel/rail contact geometry. The results show that the prediction model can reflect wear characteristics of measured profiles and vehicle performances.

  14. Longitudinal type-line optimization of high-speed train for low aerodynamic noise

    Institute of Scientific and Technical Information of China (English)

    肖友刚; 杨群; 孙亮; 时彧

    2014-01-01

    The basic head shape of high-speed train is determined by its longitudinal type-line (LTL), so it is crucial to optimize its aerodynamic performance. Based on the parametric modeling of LTL constructed by non-uniform relational B-spline (NURBS) and the fluctuation pressure obtained by large eddy simulation (LES), the Kriging surrogate model (KSM) of LTL was constructed for low aerodynamic noise, and the accuracy of the KSM was improved gradually by adding the sample point with maximum expected improvement (EI) and the optimal point from optimization. The optimal objective was searched with genetic algorithm (GA). The results show that the total fluctuation pressure level (FPL) of the optimal LTL can be 8.7 dB less than that of original one, and the shape optimization method is feasible for low aerodynamic noise design.

  15. 高速列车服役性能研究%Study on high-speed train service performance

    Institute of Scientific and Technical Information of China (English)

    林建辉; 易彩; 张卫华; 丁建明; 刘璐; 张兵

    2015-01-01

    高速列车运行时空上的跨越所面临的振动、环境变化,使其服役状态与安全性态始终处于时变状态,给高速列车安全保障与健康维护带来极大的挑战。随着高速列车运营里程的增长,高速列车服役性能的研究成为保障我国高速列车技术持续发展的重要课题。在分析高速列车服役性能基本内容的基础上,提出了高速列车服役性能检测体系,阐明了其建设内容与方案,并发展了高速列车走行部跟踪试验技术,跟踪试验对高速列车服役性能的研究具有显著成效与提升。最后,指出了本领域今后的发展趋势及需重点关注与加强的研究工作。%Due to the space-time span,there always is variation on the vibration and climate, which makes the service status and safety state of high-speed trains remain the time-varying, and at the same time it brings huge challenges to high-speed train security assurance and health maintenance. As the growth of the high-speed train operation mileage,studying on the service performance of high-speed train become an important topic as a guarantee for sustainable devel-opment of China’s high-speed train technology. Based on the content analysis of the high-speed train service performance,the high-speed train service performance testing system is present-ed,and its construction content and scheme is expounded. On this basis,the high-speed train tracking test technology is developed,which has significant efficiency and promotion for the studying on service performance of high-speed train. Finally,the development trend and strengthen research work of this study field in the future is indicated.

  16. Focusing of Rayleigh waves generated by high-speed trains under the condition of ground vibration boom

    CERN Document Server

    Krylov, Victor V

    2015-01-01

    In the present paper, the effects of focusing of Rayleigh waves generated by high speed trains in the supporting ground under the condition of ground vibration boom are considered theoretically. These effects are similar to the effects of focusing of sound waves radiated by aircraft under the condition of sonic boom. In particular, if a railway track has a bend to provide the possibility of changing direction of train movement, the Rayleigh surface waves generated by high-speed trains under the condition of ground vibration boom may become focused. This results in concentration of their energy along a simple caustic line at one side of the track and in the corresponding increase in ground vibration amplitudes. The effect of focusing of Rayleigh waves may occur also if a train moves along a straight line with acceleration and its current speed is higher than Rayleigh wave velocity in the ground. The obtained results are illustrated by numerical calculations.

  17. Unsteady simulation for a high-speed train entering a tunnel

    Institute of Scientific and Technical Information of China (English)

    Xin-hua LI; Jian DENG; Da-wei CHEN; Fang-fang XIE; Yao ZHENG

    2011-01-01

    In order to study the unsteady aerodynamics effects in railway turmels,the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved,and the two-equation k-ε model is used in the simulation of turbulence,while the dynamic grid technique is employed for moving bodies.We focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface,and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel exit.It is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed,so are the microwave and the drag of the train.

  18. Acoustic model of micro-pressure wave emission from a high-speed train tunnel

    Science.gov (United States)

    Miyachi, T.

    2017-03-01

    The micro-pressure wave (MPW) radiated from a tunnel portal can, if audible, cause serious problems around tunnel portals in high-speed railways. This has created a need to develop an acoustic model that considers the topography around a radiation portal in order to predict MPWs more accurately and allow for higher speed railways in the future. An acoustic model of MPWs based on linear acoustic theory is developed in this study. First, the directivity of sound sources and the acoustical effect of topography are investigated using a train launcher facility around a portal on infinitely flat ground and with an infinite vertical baffle plate. The validity of linear acoustic theory is then discussed through a comparison of numerical results obtained using the finite difference method (FDM) and experimental results. Finally, an acoustic model is derived that considers sound sources up to the second order and Green's function to represent the directivity and effect of topography, respectively. The results predicted by this acoustic model are shown to be in good agreement with both numerical and experimental results.

  19. Reliable dissipative control of high-speed train with probabilistic time-varying delays

    Science.gov (United States)

    Kaviarasan, B.; Sakthivel, R.; Shi, Y.

    2016-12-01

    This paper investigates the reliable dissipative control problem for high-speed trains (HSTs) under probabilistic time-varying sampling with a known upper bound on the sampling intervals. In particular, random variables obeying the Bernoulli distribution are considered to account for the probabilistic time-varying delays. Based on Lyapunov-Krasovskii functional approach which considers full use of the available information about actual sampling pattern, a new set of sufficient condition is established to guarantee that the HST can well track the desired speed and the relative spring displacement between the two neighbouring carriages is asymptotically stable and the corresponding error system is strictly ?-dissipative. The existence condition of the dissipativity-based reliable sampled-data controller is obtained in terms of a set of linear matrix inequalities which are delay-distribution-dependent, i.e. the solvability of the condition depends on not only the variation range of the delay but also the probability distribution of it. Moreover, different control processes for the HST system can be obtained from the proposed design procedure and hence it can reduce the time and cost. Finally, the effectiveness and benefits of the proposed control law is demonstrated through a numerical example by taking the experimental values of Japan Shinkansen HST.

  20. Multi-Objective Aerodynamic Optimization of the Streamlined Shape of High-Speed Trains Based on the Kriging Model.

    Science.gov (United States)

    Xu, Gang; Liang, Xifeng; Yao, Shuanbao; Chen, Dawei; Li, Zhiwei

    2017-01-01

    Minimizing the aerodynamic drag and the lift of the train coach remains a key issue for high-speed trains. With the development of computing technology and computational fluid dynamics (CFD) in the engineering field, CFD has been successfully applied to the design process of high-speed trains. However, developing a new streamlined shape for high-speed trains with excellent aerodynamic performance requires huge computational costs. Furthermore, relationships between multiple design variables and the aerodynamic loads are seldom obtained. In the present study, the Kriging surrogate model is used to perform a multi-objective optimization of the streamlined shape of high-speed trains, where the drag and the lift of the train coach are the optimization objectives. To improve the prediction accuracy of the Kriging model, the cross-validation method is used to construct the optimal Kriging model. The optimization results show that the two objectives are efficiently optimized, indicating that the optimization strategy used in the present study can greatly improve the optimization efficiency and meet the engineering requirements.

  1. Zefiro 380. The new very high speed train for China; Zefiro 380. Der neue Hochgeschwindigkeitszug fuer China

    Energy Technology Data Exchange (ETDEWEB)

    Hoefler, Werner; Niklass, Ralf [Bombardier Transportation GmbH, Hennigsdorf (Germany)

    2013-04-01

    The Bombardier Zefiro 380 comprehensively redefines very high speed (VHS) travel by harmonizing the often-conflicting demands of economy and ecology. In China's visionary development of a national very high speed rail system, the Zefiro 380 train plays a key role: 70 of these train sets were ordered by the Ministry of Railways in September 2009. The world's fastest series-production train is also the world's most eco-friendly and one of the most economical VHS trains. Bombardier's energy-saving EC04 technologies and an advanced aerodynamic design that benefits from Bombardier's aviation know-how ensure that the Zefiro 380 train runs with an unprecedented degree of energy efficiency.

  2. Combined effect of noise and vibration produced by high-speed trains on annoyance in buildings.

    Science.gov (United States)

    Lee, Pyoung Jik; Griffin, Michael J

    2013-04-01

    The effects of noise and vibration on annoyance in buildings during the passage of a nearby high-speed train have been investigated in a laboratory experiment with recorded train noise and 20 Hz vibration. The noises included the effects of two types of façade: windows-open and windows-closed. Subjects were exposed to six levels of noise and six magnitudes of vibration, and asked to rate annoyance using an 11-point numerical scale. The experiment consisted of four sessions: (1) evaluation of noise annoyance in the absence of vibration, (2) evaluation of total annoyance from simultaneous noise and vibration, (3) evaluation of noise annoyance in the presence of vibration, and (4) evaluation of vibration annoyance in the absence of noise. The results show that vibration did not influence ratings of noise annoyance, but that total annoyance caused by combined noise and vibration was considerably greater than the annoyance caused by noise alone. The noise annoyance and the total annoyance caused by combined noise and vibration were associated with subject self-ratings of noise sensitivity. Two classical models of total annoyance due to combined noise sources (maximum of the single source annoyance or the integration of individual annoyance ratings) provided useful predictions of the total annoyance caused by simultaneous noise and vibration.

  3. Numerical study on the aerodynamic performance and safe running of high-speed trains in sandstorms

    Institute of Scientific and Technical Information of China (English)

    Hong-bing XIONG; Wen-guang YU; Da-wei CHEN; Xue-ming SHAO

    2011-01-01

    The influence of sandstorms on train aerodynamic performance and safe running was studied in response to the frequent occurrence of sandstorm weather in north China.An Eulerian two-phase model in the computational fluid dynamic (CFD) software FLUENT,validated with published data,was used to solve the gas-solid multiphase flow of a sandstorm around a train.The train aerodynamic performance under different sandstorm levels and no sand conditions was then simulated.Results showed that in sandstorm weather,the drag,lift,side forces and overturning moment increase by variable degrees.Based on a numerical analysis of aerodynamic characteristics,an equation of train stability was also derived using the theory of moment balance from the view of dynamics.A recommended speed limit of a train under different sandstorm levels was calculated based on the stability analysis.

  4. Optimal Design of the Absolute Positioning Sensor for a High-Speed Maglev Train and Research on Its Fault Diagnosis

    OpenAIRE

    2012-01-01

    This paper studies an absolute positioning sensor for a high-speed maglev train and its fault diagnosis method. The absolute positioning sensor is an important sensor for the high-speed maglev train to accomplish its synchronous traction. It is used to calibrate the error of the relative positioning sensor which is used to provide the magnetic phase signal. On the basis of the analysis for the principle of the absolute positioning sensor, the paper describes the design of the sending and rece...

  5. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    Science.gov (United States)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  6. Three-Dimensional Dynamic Analyses of Track-Embankment-Ground System Subjected to High Speed Train Loads

    Directory of Open Access Journals (Sweden)

    Qiang Fu

    2014-01-01

    Full Text Available A three-dimensional finite element model was developed to investigate dynamic response of track-embankment-ground system subjected to moving loads caused by high speed trains. The track-embankment-ground systems such as the sleepers, the ballast, the embankment, and the ground are represented by 8-noded solid elements. The infinite elements are used to represent the infinite boundary condition to absorb vibration waves induced by the passing of train load at the boundary. The loads were applied on the rails directly to simulate the real moving loads of trains. The effects of train speed on dynamic response of the system are considered. The effect of material parameters, especially the modulus changes of ballast and embankment, is taken into account to demonstrate the effectiveness of strengthening the ballast, embankment, and ground for mitigating system vibration in detail. The numerical results show that the model is reliable for predicting the amplitude of vibrations produced in the track-embankment-ground system by high-speed trains. Stiffening of fill under the embankment can reduce the vibration level, on the other hand, it can be realized by installing a concrete slab under the embankment. The influence of axle load on the vibration of the system is obviously lower than that of train speed.

  7. Three-Dimensional Dynamic Analyses of Track-Embankment-Ground System Subjected to High Speed Train Loads

    Science.gov (United States)

    2014-01-01

    A three-dimensional finite element model was developed to investigate dynamic response of track-embankment-ground system subjected to moving loads caused by high speed trains. The track-embankment-ground systems such as the sleepers, the ballast, the embankment, and the ground are represented by 8-noded solid elements. The infinite elements are used to represent the infinite boundary condition to absorb vibration waves induced by the passing of train load at the boundary. The loads were applied on the rails directly to simulate the real moving loads of trains. The effects of train speed on dynamic response of the system are considered. The effect of material parameters, especially the modulus changes of ballast and embankment, is taken into account to demonstrate the effectiveness of strengthening the ballast, embankment, and ground for mitigating system vibration in detail. The numerical results show that the model is reliable for predicting the amplitude of vibrations produced in the track-embankment-ground system by high-speed trains. Stiffening of fill under the embankment can reduce the vibration level, on the other hand, it can be realized by installing a concrete slab under the embankment. The influence of axle load on the vibration of the system is obviously lower than that of train speed. PMID:24723838

  8. Real Time Cardan Shaft State Estimation of High-Speed Train Based on Ensemble Empirical Mode Decomposition

    OpenAIRE

    Cai Yi; Jianhui Lin; Tengda Ruan; Yanping Li

    2015-01-01

    Due to the special location and structure of transmission system on high-speed train named CRH5, dynamic unbalance state of the cardan shaft will pose a threat to the train servicing safety, so effective methods that test the cardan shaft operating information and estimate the performance state in real time are needed. In this study a useful estimation method based on ensemble empirical mode decomposition (EEMD) is presented. By using this method, time-frequency characteristic of cardan shaft...

  9. Numerical simulation of flow around a simplified high-speed train model using OpenFOAM

    Science.gov (United States)

    Ishak, I. A.; Ali, M. S. M.; Shaikh Salim, S. A. Z.

    2016-10-01

    Detailed understanding of flow physics on the flow over a high-speed train (HST) can be accomplished using the vast information obtained from numerical simulation. Accuracy of any simulation in solving and analyzing problems related to fluid flow is important since it measures the reliability of the results. This paper describes a numerical simulation setup for the flow around a simplified model of HST that utilized open source software, OpenFOAM. The simulation results including pressure coefficient, drag coefficient and flow visualization are presented and they agreed well with previously published data. This shows that OpenFOAM software is capable of simulating fluid flows around a simplified HST model. Additionally, the wall functions are implemented in order to minimize the overall number of grid especially near the wall region. This resulted in considerably smaller numbers of mesh resolution used in the current study compared to previous work, which leads to achievement of much reasonable time simulation and consequently reduces the total computational effort without affecting the final outcome.

  10. Electromagnetic Field Analysis and Modeling of a Relative Position Detection Sensor for High Speed Maglev Trains

    Science.gov (United States)

    Xue, Song; He, Ning; Long, Zhiqiang

    2012-01-01

    The long stator track for high speed maglev trains has a tooth-slot structure. The sensor obtains precise relative position information for the traction system by detecting the long stator tooth-slot structure based on nondestructive detection technology. The magnetic field modeling of the sensor is a typical three-dimensional (3-D) electromagnetic problem with complex boundary conditions, and is studied semi-analytically in this paper. A second-order vector potential (SOVP) is introduced to simplify the vector field problem to a scalar field one, the solution of which can be expressed in terms of series expansions according to Multipole Theory (MT) and the New Equivalent Source (NES) method. The coefficients of the expansions are determined by the least squares method based on the boundary conditions. Then, the solution is compared to the simulation result through Finite Element Analysis (FEA). The comparison results show that the semi-analytical solution agrees approximately with the numerical solution. Finally, based on electromagnetic modeling, a difference coil structure is designed to improve the sensitivity and accuracy of the sensor. PMID:22778652

  11. DAMAGE TOLERANCE ANALYSIS ON HOLLOW AXLES OF HIGH SPEED MOTOR TRAINS

    Institute of Scientific and Technical Information of China (English)

    ZHOU Suxia; XIE Jilong; YANG Guangxue; XIAO Nan

    2008-01-01

    According to the rules of UIC515-3, the service loads of the axles are defined, which include some different loads cases as follows: the static loads; the impact loads resulted from running through the rail joints and unevenness rails; the loads through curves and from braking. Through the calculating and analysis, the stress distribution of the hollow axles is obtained for 200 km/h high speed motor trains used in China. At the same time, the fatigue crack growth of hollow axles is studied, and the initial surface cracks of 2 mm depth caused by hard objects strike or the other causes are discussed. On the basis of the linear elastic fracture mechanics theory, the stress intensity factor of the crack of the geometry transition outside the wheel seat is also studied. Associated with fatigue crack propagation equation and the corresponding crack propagation threshold, the crack propagation characteristics under different shapes are calculated. Then the running distances are educed with different shapes propagating to the critical length, and the estimation of the residual lives about hollow axles which are the reference values of examine and repair limit of the hollow axle is given.

  12. Numerical simulation of high-speed train induced ground vibrations using 2.5D finite element approach

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An efficient 2.5D finite element numerical modeling approach was developed to simulate wave motions generated in ground by high-speed train passages. Fourier transform with respect to the coordinate in the track direction was applied to re-ducing the three-dimensional dynamic problem to a plane strain problem which has been solved in a section perpendicular to the track direction. In this study, the track structure and supporting ballast layer were simplified as a composite Euler beam resting on the ground surface, while the ground with complicated geometry and physical properties was modeled by 2.5D quadrilateral elements. Wave dissipation into the far field was dealt with the transmitting boundary constructed with fre-quency-dependent dashpots. Three-dimensional responses of track structure and ground were obtained from the wavenumber expansion in the track direction. The simulated wave motions in ground were interpreted for train moving loads traveling at speeds below or above the critical velocity of a specific track-ground system. It is found that, in the soft ground area, the high-speed train operations can enter the transonic range, which can lead to resonances of the track structure and the sup-porting ground. The strong vibration will endanger the safe operations of high-speed train and accelerate the deterioration of railway structure.

  13. Numerical simulation of high-speed train induced ground vibrations using 2.5D finite element approach

    Institute of Scientific and Technical Information of China (English)

    BIAN XueCheng; OHEN YunMin; HU Ting

    2008-01-01

    An efficient 2.5D finite element numerical modeling approach was developed to simulate wave motions generated in ground by high-speed train passages.Fourier transform with respect to the coordinate in the track direction was applied to re-ducing the three-dimensional dynamic problem to a plane strain problem which has been solved in a section perpendicular to the track direction.In this study,the track structure and supporting ballast layer were simplified as a composite Euler beam resting on the ground surface,while the ground with complicated geometry and physical properties was modeled by 2.5D quadrilateral elements.Wave dissipation into the far field was dealt with the transmitting boundary constructed with fre-quency-dependent dashpots.Three-dimensional responses of track structure and ground were obtained from the wavenumber expansion in the track direction.The simulated wave motions in ground were interpreted for train moving loads traveling at speeds below or above the critical velocity of a specific track-ground system.It is found that,in the soft ground area,the high-speed train operations can enter the transonic range,which can lead to resonances of the track structure and the sup-porting ground.The strong vibration will endanger the safe operations of high-speed train and accelerate the deterioration of railway structure.

  14. On the Analytical Approach to Present Engineering Problems: Photovoltaic Systems Behavior, Wind Speed Sensors Performance, and High-Speed Train Pressure Wave Effects in Tunnels

    Directory of Open Access Journals (Sweden)

    Santiago Pindado

    2015-01-01

    Full Text Available At present, engineering problems required quite a sophisticated calculation means. However, analytical models still can prove to be a useful tool for engineers and scientists when dealing with complex physical phenomena. The mathematical models developed to analyze three different engineering problems: photovoltaic devices analysis; cup anemometer performance; and high-speed train pressure wave effects in tunnels are described. In all cases, the results are quite accurate when compared to testing measurements.

  15. Low-load high-repetition resistance training improves strength and gait speed in middle-aged and older adults.

    Science.gov (United States)

    Nicholson, Vaughan P; McKean, Mark R; Burkett, Brendan J

    2015-09-01

    To determine the effect of 26 weeks of low-load high-repetition resistance training (BodyPump™) on maximal strength, gait speed, balance and self-reported health status in healthy, active middle-aged and older adults. Two-group randomised control trial. Sixty-eight apparently healthy, active adults aged over 55 years completed either 26 weeks of BodyPump™ training (PUMP) or served as control participants (CON). The BodyPump™ group (n = 32, age = 66 ± 4 years) trained twice per week for 26 weeks while the control group (n = 36, age = 66 ± 5 years) continued with their normal activities. Leg-press and Smith-machine bench-press one repetition maximum (1RM), gait speed, balance, and self-reported health status were all assessed at baseline and follow-up. Significant group-by-time interactions in favour of the BodyPump™ group were found for leg-press 1RM (PUMP + 13%, CON + 3%, p = 0.007, partial eta(2) = 0.11), Smith-machine bench-press 1RM (PUMP + 14%, CON +5%, p = 0.001, partial eta(2) = 0.18), normal gait speed (PUMP + 23%, CON +9 %, p = 0.028, partial eta(2) = 0.08) and single leg balance right (PUMP + 24%, CON - 7%, p = 0.006, partial eta(2) = 0.12). There were no group-by-time interactions for health status measures. Three participants in the BodyPump™ group withdrew from training due to injury or fear of injury related to training. Low-load high-repetition resistance training in the form of BodyPump™ is effective at improving maximal strength, gait speed and some aspects of standing balance in adults over 55 years. The training was well tolerated by the majority of participants. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Prediction and mitigation analysis of ground vibration caused by running high-speed trains on rigid-frame viaducts

    Science.gov (United States)

    Sun, Liangming; Xie, Weiping; He, Xingwen; Hayashikawa, Toshiro

    2016-03-01

    In this study a 3D numerical analysis approach is developed to predict the ground vibration around rigid-frame viaducts induced by running high-speed trains. The train-bridge-ground interaction system is divided into two subsystems: the train-bridge interaction and the soil-structure interaction. First, the analytical program to simulate bridge vibration with consideration of train-bridge interaction is developed to obtain the vibration reaction forces at the pier bottoms. The highspeed train is described by a multi-DOFs vibration system and the rigid-frame viaduct is modeled with 3D beam elements. Second, applying these vibration reaction forces as input external excitations, the ground vibration is simulated by using a general-purpose program that includes soil-structure interaction effects. The validity of the analytical procedure is confirmed by comparing analytical and experimental results. The characteristics of high-speed train-induced vibrations, including the location of predominant vibration, are clarified. Based on this information a proposed vibration countermeasure using steel strut and new barrier is found effective in reducing train-induced vibrations and it satisfies environmental vibration requirements. The vibration screening efficiency is evaluated by reduction VAL based on 1/3 octave band spectral analysis.

  17. Effects of endurance training on reduction of plasma glucose during high intensity constant and incremental speed tests in Wistar rats.

    Science.gov (United States)

    Abreu, P; Vitzel, K F; Monteiro, I C C R; Lima, T I; Queiroz, A N; Leal-Cardoso, J H; Hirabara, S M; Ceccatto, V M

    2016-10-24

    The aim of this research was to investigate the effects of endurance training on reduction of plasma glucose during high intensity constant and incremental speed tests in Wistar rats. We hypothesized that plasma glucose might be decreased in the exercised group during heavy (more intense) exercise. Twenty-four 10-week-old male Wistar rats were randomly assigned to sedentary and exercised groups. The prescription of endurance exercise training intensity was determined as 60% of the maximum intensity reached at the incremental speed test. The animals were trained by running on a motorized treadmill, five days/week for a total period of 67 weeks. Plasma glucose during the constant speed test in the exercised group at 20 m/min was reduced at the 14th, 21st and 28th min compared to the sedentary group, as well at 25 m/min at the 21st and 28th min. Plasma glucose during the incremental speed test was decreased in the exercised group at the moment of exhaustion (48th min) compared to the sedentary group (27th min). Endurance training positively modulates the mitochondrial activity and capacity of substrate oxidation in muscle and liver. Thus, in contrast to other studies on high load of exercise, the effects of endurance training on the decrease of plasma glucose during constant and incremental speed tests was significantly higher in exercised than in sedentary rats and associated with improved muscle and hepatic oxidative capacity, constituting an important non-pharmacological intervention tool for the prevention of insulin resistance, including type 2 diabetes mellitus.

  18. Effects of endurance training on reduction of plasma glucose during high intensity constant and incremental speed tests in Wistar rats

    Directory of Open Access Journals (Sweden)

    P. Abreu

    Full Text Available The aim of this research was to investigate the effects of endurance training on reduction of plasma glucose during high intensity constant and incremental speed tests in Wistar rats. We hypothesized that plasma glucose might be decreased in the exercised group during heavy (more intense exercise. Twenty-four 10-week-old male Wistar rats were randomly assigned to sedentary and exercised groups. The prescription of endurance exercise training intensity was determined as 60% of the maximum intensity reached at the incremental speed test. The animals were trained by running on a motorized treadmill, five days/week for a total period of 67 weeks. Plasma glucose during the constant speed test in the exercised group at 20 m/min was reduced at the 14th, 21st and 28th min compared to the sedentary group, as well at 25 m/min at the 21st and 28th min. Plasma glucose during the incremental speed test was decreased in the exercised group at the moment of exhaustion (48th min compared to the sedentary group (27th min. Endurance training positively modulates the mitochondrial activity and capacity of substrate oxidation in muscle and liver. Thus, in contrast to other studies on high load of exercise, the effects of endurance training on the decrease of plasma glucose during constant and incremental speed tests was significantly higher in exercised than in sedentary rats and associated with improved muscle and hepatic oxidative capacity, constituting an important non-pharmacological intervention tool for the prevention of insulin resistance, including type 2 diabetes mellitus.

  19. Train Stop Scheduling in a High-Speed Rail Network by Utilizing a Two-Stage Approach

    Directory of Open Access Journals (Sweden)

    Huiling Fu

    2012-01-01

    Full Text Available Among the most commonly used methods of scheduling train stops are practical experience and various “one-step” optimal models. These methods face problems of direct transferability and computational complexity when considering a large-scale high-speed rail (HSR network such as the one in China. This paper introduces a two-stage approach for train stop scheduling with a goal of efficiently organizing passenger traffic into a rational train stop pattern combination while retaining features of regularity, connectivity, and rapidity (RCR. Based on a three-level station classification definition, a mixed integer programming model and a train operating tactics descriptive model along with the computing algorithm are developed and presented for the two stages. A real-world numerical example is presented using the Chinese HSR network as the setting. The performance of the train stop schedule and the applicability of the proposed approach are evaluated from the perspective of maintaining RCR.

  20. Gear Design Effects on the Performance of High Speed Helical Gear Trains as Used in Aerospace Drive Systems

    Science.gov (United States)

    Handschuh, R.; Kilmain, C.; Ehinger, R.; Sinusas, E.

    2013-01-01

    The performance of high-speed helical gear trains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction / torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High Speed Helical Gear Train Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160 to 250 degF) and lubricating jet pressure (60 to 80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears. The empirical data resulting from this study will be useful to the design of future helical gear train systems anticipated for next generation rotorcraft drive systems.

  1. Performance of IEE 802.15.4 Mac layer for lab & field test for high speed train

    OpenAIRE

    2009-01-01

    Several proposals are now in research and development for wireless sensor networks(WSN) to apply on railway systems for high speed lanes and others slow and medium speed systems, some are working between communications from train to Local Operation Point(LOP) and then to the Network Operation Center (NOC) and others from a specific sensorized network to the LOP and then to NOC, we are focus in between LOP and sensors. In order to monitor, control, secure, adapt, focus, and to have...

  2. 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.

  3. In situ health monitoring for bogie systems of CRH380 train on Beijing-Shanghai high-speed railway

    Science.gov (United States)

    Hong, Ming; Wang, Qiang; Su, Zhongqing; Cheng, Li

    2014-04-01

    Based on the authors' research efforts over the years, an in situ structural health monitoring (SHM) technique taking advantage of guided elastic waves has been developed and deployed via an online diagnosis system. The technique and the system were recently implemented on China's latest high-speed train (CRH380CL) operated on Beijing-Shanghai High-Speed Railway. The system incorporated modularized components including active sensor network, active wave generation, multi-channel data acquisition, signal processing, data fusion, and results presentation. The sensor network, inspired by a new concept—"decentralized standard sensing", was integrated into the bogie frames during the final assembly of CRH380CL, to generate and acquire bogie-guided ultrasonic waves, from which a wide array of signal features were extracted. Fusion of signal features through a diagnostic imaging algorithm led to a graphic illustration of the overall health state of the bogie in a real-time and intuitive manner. The in situ experimentation covered a variety of high-speed train operation events including startup, acceleration/deceleration, full-speed operation (300 km/h), emergency braking, track change, as well as full stop. Mock-up damage affixed to the bogie was identified quantitatively and visualized in images. This in situ testing has demonstrated the feasibility, effectiveness, sensitivity, and reliability of the developed SHM technique and the system towards real-world applications.

  4. Theoretical research and experimental validation of elastic dynamic load spectra on bogie frame of high-speed train

    Science.gov (United States)

    Zhu, Ning; Sun, Shouguang; Li, Qiang; Zou, Hua

    2016-05-01

    When a train runs at high speeds, the external exciting frequencies approach the natural frequencies of bogie critical components, thereby inducing strong elastic vibrations. The present international reliability test evaluation standard and design criteria of bogie frames are all based on the quasi-static deformation hypothesis. Structural fatigue damage generated by structural elastic vibrations has not yet been included. In this paper, theoretical research and experimental validation are done on elastic dynamic load spectra on bogie frame of high-speed train. The construction of the load series that correspond to elastic dynamic deformation modes is studied. The simplified form of the load series is obtained. A theory of simplified dynamic load-time histories is then deduced. Measured data from the Beijing-Shanghai Dedicated Passenger Line are introduced to derive the simplified dynamic load-time histories. The simplified dynamic discrete load spectra of bogie frame are established. Based on the damage consistency criterion and a genetic algorithm, damage consistency calibration of the simplified dynamic load spectra is finally performed. The computed result proves that the simplified load series is reasonable. The calibrated damage that corresponds to the elastic dynamic discrete load spectra can cover the actual damage at the operating conditions. The calibrated damage satisfies the safety requirement of damage consistency criterion for bogie frame. This research is helpful for investigating the standardized load spectra of bogie frame of high-speed train.

  5. Comparative Effect of Power Training and High-Speed Yoga on Motor Function in Older Patients With Parkinson Disease.

    Science.gov (United States)

    Ni, Meng; Signorile, Joseph F; Mooney, Kiersten; Balachandran, Anoop; Potiaumpai, Melanie; Luca, Corneliu; Moore, James G; Kuenze, Christopher M; Eltoukhy, Moataz; Perry, Arlette C

    2016-03-01

    To compare the effects of power training (PWT) and a high-speed yoga program on physical performances in older patients with Parkinson disease (PD), and to test the hypothesis that both training interventions would attenuate PD symptoms and improve physical performance. Randomized controlled trial. A laboratory of neuromuscular research and active aging. Patients with PD (N=41; mean age ± SD, 72.2 ± 6.5y). Two high-speed exercise interventions (specifically designed yoga program and PWT) were given for 12 weeks (twice a week), and 1 nonexercise control group. Unified Parkinson Disease Rating Scale motor score (UPDRSMS), Berg Balance Scale (BBS), Mini-Balance Evaluation Systems Test (Mini-BESTest), Timed Up and Go, functional reach, single leg stance (SLS), postural sway test, 10-m usual and maximal walking speed tests, 1 repetition maximum (RM), and peak power (PPW) for leg press. For the posttests, both training groups showed significant improvements (Pyoga program and PWT. Both the specially designed yoga program and PWT programs can significantly improve physical performance in older persons with PD. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  6. Mobile relays for enhanced broadband connectivity in high speed train systems

    KAUST Repository

    Yaacoub, Elias E.

    2014-09-01

    With the introduction of wireless modems and smart phones, the passenger transport industry is witnessing a high demand to ensure not only the safety of the trains, but also to provide users with Internet access all the time inside the train. When the Mobile Terminal (MT) communicates directly with the Base Station (BS), it will experience a severe degradation in the Quality of Service due to the path loss and shadowing effects as the wireless signal is traveling through the train. In this paper, we study the performance in the case of relays placed on top of each train car. In the proposed approach, these relays communicate with the cellular BS on one hand, and with the MTs inside the train cars on the other hand, using the Long Term Evolution (LTE) cellular technology. A low complexity heuristic LTE radio resource management approach is proposed and compared to the Hungarian algorithm, both in the presence and absence of the relays. The presence of the relays is shown to lead to significant enhancements in the effective data rates of the MTs. In addition, the proposed resource management approach is shown to reach a performance close to the optimal Hungarian algorithm. © 2014 Elsevier B.V.

  7. Application of sound intensity and partial coherence to identify interior noise sources on the high speed train

    Science.gov (United States)

    Fan, Rongping; Su, Zhongqing; Meng, Guang; He, Caichun

    2014-06-01

    In order to provide a quieter riding environment for passengers, sound quality refinement of rail vehicle is a hot issue. Identification of interior noise sources is the prerequisite condition to reduce the interior noise on high speed train. By considering contribution of noise sources such as rolling noise, mechanical equipment noise, structure-borne noise radiated by car body vibration to the interior noise, the synthesized measurement of sound intensity, sound pressure levels and vibration have been carried out in four different carriages on high speed train. The sound intensity and partial coherence methods have been used to identify the most significant interior noise sources. The statistical analysis results of sound intensity near window and floor on four carriages indicate that sound intensity near floor is higher than that near window at three traveling speeds. Ordinary and partial coherent analysis of vibro-acoustical signals show that the major internal noise source is structural-borne sound radiated by floor vibration. These findings can be utilized to facilitate the reduction of interior noise in the future.

  8. Coronal Heating and Acceleration of the High/Low-Speed Solar Wind by Fast/Slow MHD Shock Trains

    CERN Document Server

    Suzuki, T K

    2004-01-01

    We investigate coronal heating and acceleration of the high- and low-speed solar wind in the open field region by dissipation of fast and slow magnetohydrodynamical (MHD) waves through MHD shocks. Linearly polarized \\Alfven (fast MHD) waves and acoustic (slow MHD) waves travelling upwardly along with a magnetic field line eventually form fast switch-on shock trains and hydrodynamical shock trains (N-waves) respectively to heat and accelerate the plasma. We determine one dimensional structure of the corona from the bottom of the transition region (TR) to 1AU under the steady-state condition by solving evolutionary equations for the shock amplitudes simultaneously with the momentum and proton/electron energy equations. Our model reproduces the overall trend of the high-speed wind from the polar holes and the low-speed wind from the mid- to low-latitude streamer except the observed hot corona in the streamer. The heating from the slow waves is effective in the low corona to increase the density there, and plays ...

  9. Optimization of High-Speed Train Control Strategy for Traction Energy Saving Using an Improved Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Ruidan Su

    2014-01-01

    Full Text Available A parallel multipopulation genetic algorithm (PMPGA is proposed to optimize the train control strategy, which reduces the energy consumption at a specified running time. The paper considered not only energy consumption, but also running time, security, and riding comfort. Also an actual railway line (Beijing-Shanghai High-Speed Railway parameter including the slop, tunnel, and curve was applied for simulation. Train traction property and braking property was explored detailed to ensure the accuracy of running. The PMPGA was also compared with the standard genetic algorithm (SGA; the influence of the fitness function representation on the search results was also explored. By running a series of simulations, energy savings were found, both qualitatively and quantitatively, which were affected by applying cursing and coasting running status. The paper compared the PMPGA with the multiobjective fuzzy optimization algorithm and differential evolution based algorithm and showed that PMPGA has achieved better result. The method can be widely applied to related high-speed train.

  10. Stiffness Characteristics of High-Speed Railway Turnout and the Effect on the Dynamic Train-Turnout Interaction

    Directory of Open Access Journals (Sweden)

    Jingmang Xu

    2016-01-01

    Full Text Available Track stiffness in railway turnouts is variable due to differences in structural composition along the longitudinal direction, which will lead to severe dynamic interaction between train and turnout. In this paper, a transient analysis model is presented to investigate the stiffness characteristics of high-speed railway turnouts based on the finite element method and is applied to optimise the stiffness of railway turnouts. Furthermore, the effect of the stiffness variations on the dynamic train-turnout interaction is analysed. The calculation results show that the track stiffness characteristics are similar in the main and diverging line of railway turnout, except for the check rail sections. Due to the existence of shared baseplates and spacer blocks between different rails, the stiffness variations in the crossing panel are most severe in high-speed railway turnouts. The stiffness differences (calculated as the ratio of the maximum and minimum stiffness of the longitudinal and lateral direction for Chinese number 18 ballasted turnout are 216% and 229%, respectively. The graded stiffness of the tie pads has been redesigned to optimise the stiffness of railway turnout based on the transient analysis model and the stiffness differences of the turnout are decreased. Altogether, the dynamic train-turnout interaction is enhanced remarkably by considering the turnout’s stiffness characteristics.

  11. Optimal Design of the Absolute Positioning Sensor for a High-Speed Maglev Train and Research on Its Fault Diagnosis

    Directory of Open Access Journals (Sweden)

    Junge Zhang

    2012-08-01

    Full Text Available This paper studies an absolute positioning sensor for a high-speed maglev train and its fault diagnosis method. The absolute positioning sensor is an important sensor for the high-speed maglev train to accomplish its synchronous traction. It is used to calibrate the error of the relative positioning sensor which is used to provide the magnetic phase signal. On the basis of the analysis for the principle of the absolute positioning sensor, the paper describes the design of the sending and receiving coils and realizes the hardware and the software for the sensor. In order to enhance the reliability of the sensor, a support vector machine is used to recognize the fault characters, and the signal flow method is used to locate the faulty parts. The diagnosis information not only can be sent to an upper center control computer to evaluate the reliability of the sensors, but also can realize on-line diagnosis for debugging and the quick detection when the maglev train is off-line. The absolute positioning sensor we study has been used in the actual project.

  12. Optimal design of the absolute positioning sensor for a high-speed maglev train and research on its fault diagnosis.

    Science.gov (United States)

    Zhang, Dapeng; Long, Zhiqiang; Xue, Song; Zhang, Junge

    2012-01-01

    This paper studies an absolute positioning sensor for a high-speed maglev train and its fault diagnosis method. The absolute positioning sensor is an important sensor for the high-speed maglev train to accomplish its synchronous traction. It is used to calibrate the error of the relative positioning sensor which is used to provide the magnetic phase signal. On the basis of the analysis for the principle of the absolute positioning sensor, the paper describes the design of the sending and receiving coils and realizes the hardware and the software for the sensor. In order to enhance the reliability of the sensor, a support vector machine is used to recognize the fault characters, and the signal flow method is used to locate the faulty parts. The diagnosis information not only can be sent to an upper center control computer to evaluate the reliability of the sensors, but also can realize on-line diagnosis for debugging and the quick detection when the maglev train is off-line. The absolute positioning sensor we study has been used in the actual project.

  13. Real Time Cardan Shaft State Estimation of High-Speed Train Based on Ensemble Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Cai Yi

    2015-01-01

    Full Text Available Due to the special location and structure of transmission system on high-speed train named CRH5, dynamic unbalance state of the cardan shaft will pose a threat to the train servicing safety, so effective methods that test the cardan shaft operating information and estimate the performance state in real time are needed. In this study a useful estimation method based on ensemble empirical mode decomposition (EEMD is presented. By using this method, time-frequency characteristic of cardan shaft can be extracted effectively by separating the gearbox vibration acceleration data. Preliminary analysis suggests that the pinions rotating vibration separated from gearbox vibration by EEMD can be used as important assessment basis to estimate cardan shaft state. With two sets gearbox vibration signals collected from the in-service train at different running speed, the comparative analysis verifies that the proposed method has high effectiveness for cardan-shaft state estimate. Of course, it needs further research to quantify the performance state of cardan shaft based on this method.

  14. Transmit Power Minimization and Base Station Planning for High-Speed Trains with Multiple Moving Relays in OFDMA Systems

    KAUST Repository

    Ghazzai, Hakim

    2016-03-15

    High-speed railway system equipped with moving relay stations placed on the middle of the ceiling of each train wagon is investigated. The users inside the train are served in two hops via the orthogonal frequency-division multiple access (OFDMA) technology. In this work, we first focus on minimizing the total downlink power consumption of the base station (BS) and the moving relays while respecting specific quality of service (QoS) constraints. We first derive the optimal resource allocation solution in terms of OFDMA subcarriers and power allocation using the dual decomposition method. Then, we propose an efficient algorithm based on the Hungarian method in order to find a suboptimal but low complexity solution. Moreover, we propose an OFDMA planning solution for high-speed train by finding the maximal inter-BS distance given the required user data rates in order to perform seamless handover. Our simulation results illustrate the performance of the proposed resource allocation schemes in the case of the 3GPP Long Term Evolution-Advanced (LTE-A) and compare them with previously developed algorithms as well as with the direct transmission scenario. Our results also highlight the significant planning gain obtained thanks to the use of multiple relays instead of the conventional single relay scenario.

  15. Analysis of Electromagnetics Forces on Magnetically Suspended High-Speed Trains

    Directory of Open Access Journals (Sweden)

    Daniel Mayer

    2004-01-01

    Full Text Available High-speed superexpresses (HSST developed by Japanese airlines (JAL are based on the electrodynamics principle of magnetic suspension. The track contains short-circuited coils and interaction between them and superconductive coils in the vehicle produces its suspension. The paper includes a mathematical model for traction electrodynamics suspension device HSST represented by a system of linear differential equations with coefficients varying in time. Numerical analysis of this model fields the velocity-dependent lift and drag forces acting on the system. The time distribution of the lift force exhibits certain oscillations that may be suppressed by suitable placement of several superconductive levitation wings in the vehicle. The results obtained are in a good agreement with the knowledge found by various authors on prototype vehicles.

  16. One-Dimensional Simulation of the Pressure Wave near the Exit of a High-Speed Train Tunnel

    Institute of Scientific and Technical Information of China (English)

    杨宇光; 朱克勤; 席葆树

    2001-01-01

    The one-dimensional (1-D) unsteady flow induced by a high-speed train entering a tunnel isnumerically studied by the method of characteristics. The tube area is dependent on time and distance. Theenergy equation used by Kage et al. is corrected to avoid the conflict with the isentropic assumption. Theeffect of the tunnel hood on the pressure wave is studied near the tunnel exit. Results show that the tunnel hoodis useful in reducing the peak value and the time derivative of the pressure wave.``

  17. Data for The flow and flow-induced noise behaviour of a simplified high-speed train bogie in a cavity and including a fairing

    OpenAIRE

    Zhu, Jianyue; Hu, Zhiwei; Thompson, David

    2017-01-01

    Dataset for the main results of paper entitled 'The flow and flow-induced noise behaviour of a simplified high-speed train bogie in a cavity and including a fairing' published in Journal of Rail and Rapid Transit.

  18. Effects of high-speed power training on muscle strength and power in patients with multiple sclerosis.

    Science.gov (United States)

    Medina-Perez, Carlos; de Souza-Teixeira, Fernanda; Fernandez-Gonzalo, Rodrigo; Hernandez-Murua, Jose-Aldo; Antonio de Paz-Fernandez, Jose

    2016-01-01

    This study examined the effects of a high-speed power training program in peak muscle power and maximal voluntary isometric contraction (MVIC) of knee extensors in patients with relapsing-remitting multiple sclerosis (MS). Forty patients, 20 women (age 42.8 +/- 10.3 yr) and 20 men (age 44.0 +/- 8.7 yr) diagnosed with relapsing-remitting MS were randomly assigned, with respect to sex, to either an exercise group or a control group. Participants from the exercise group performed 12 wk of supervised muscle power training of knee extensors. All subjects were tested for MVIC and peak muscle power at baseline and after the training intervention. A strain gauge was used to measure the MVIC, and peak muscle power was assessed with a linear encoder at five relative loads. The training-related effects were assessed using a t-test. The results showed no significant changes in the control group from baseline to postintervention evaluation. In contrast, the exercise group significantly increased MVIC (10.8%; p muscle power at 40, 50, 60, 70, and 80% of the MVIC by 21.8, 14.5, 17.3, 19.4, and 22.3%, respectively (p power training improve both MVIC and muscle power at five different loads in patients with relapsing-remitting MS.

  19. Detached-eddy simulation of flow around high-speed train on a bridge under cross winds

    Institute of Scientific and Technical Information of China (English)

    陈敬文; 高广军; 朱春丽

    2016-01-01

    In order to describe an investigation of the flow around high-speed train on a bridge under cross winds using detached-eddy simulation (DES), a 1/8th scale model of a three-car high-speed train and a typical bridge model are employed, Numerical wind tunnel technology based on computational fluid dynamics (CFD) is used, and the CFD models are set as stationary models. The Reynolds number of the flow, based on the inflow velocity and the height of the vehicle, is 1.9×106. The computations are conducted under three cases, train on the windward track on the bridge (WWC), train on the leeward track on the bridge (LWC) and train on the flat ground (FGC). Commercial software FLUENT is used and the mesh sensitivity research is carried out by three different grids: coarse, medium and fine. Results show that compared with FGC case, the side force coefficients of the head cars for the WWC and LWC cases increases by 14% and 29%, respectively; the coefficients of middle cars for the WWC and LWC increase by 32% and 10%, respectively; and that of the tail car increases by 45% for the WWC whereas decreases by 2% for the LWC case. The most notable thing is that the side force and the rolling moment of the head car are greater for the LWC, while the side force and the rolling moment of the middle car and the tail car are greater for the WWC. Comparing the velocity profiles at different locations, the flow is significantly influenced by the bridge−train system when the air is close to it. For the three cases (WWC, LWC and FGC), the pressure on the windward side of train is mostly positive while that of the leeward side is negative. The discrepancy of train’s aerodynamic force is due to the different surface area of positive pressure and negative pressure zone. Many vortices are born on the leeward edge of the roofs. Theses vortices develop downstream, detach and dissipate into the wake region. The eddies develop irregularly, leading to a noticeably turbulent flow at leeward side

  20. Heterogeneous LTE/802.11a mobile relays for data rate enhancement and energy-efficiency in high speed trains

    KAUST Repository

    Atat, Rachad

    2012-12-01

    Performance enhancements of cellular networks for passengers in high speed railway systems are investigated. Relays placed on top of each train car are proposed. These relays communicate with the cellular base station (BS) over Long Term Evolution (LTE) long range links and with the mobile terminals (MTs) inside the train cars using IEEE 802.11a short range links. Scenarios with unicasting and multicasting from the BS are studied, both in the presence and absence of the relays. In addition, LTE resource allocation is taken into account. The presence of the relays is shown to lead to significant enhancements in the effective data rates of the MTs, in addition to leading to huge savings in the energy consumption from the batteries of the MTs. © 2012 IEEE.

  1. Speech privacy and annoyance considerations in the acoustic environment of passenger cars of high-speed trains.

    Science.gov (United States)

    Jeon, Jin Yong; Hong, Joo Young; Jang, Hyung Suk; Kim, Jae Hyeon

    2015-12-01

    It is necessary to consider not only annoyance of interior noises but also speech privacy to achieve acoustic comfort in a passenger car of a high-speed train because speech from other passengers can be annoying. This study aimed to explore an optimal acoustic environment to satisfy speech privacy and reduce annoyance in a passenger car. Two experiments were conducted using speech sources and compartment noise of a high speed train with varying speech-to-noise ratios (SNRA) and background noise levels (BNL). Speech intelligibility was tested in experiment I, and in experiment II, perceived speech privacy, annoyance, and acoustic comfort of combined sounds with speech and background noise were assessed. The results show that speech privacy and annoyance were significantly influenced by the SNRA. In particular, the acoustic comfort was evaluated as acceptable when the SNRA was less than -6 dB for both speech privacy and noise annoyance. In addition, annoyance increased significantly as the BNL exceeded 63 dBA, whereas the effect of the background-noise level on the speech privacy was not significant. These findings suggest that an optimal level of interior noise in a passenger car might exist between 59 and 63 dBA, taking normal speech levels into account.

  2. Investigation into external noise of a high-speed train at different speeds%不同速度高速列车车外噪声的调查研究

    Institute of Scientific and Technical Information of China (English)

    Bin HE; Xin-biao XIAO; Qiang ZHOU; Zhi-hui LI; Xue-song JIN‡

    2014-01-01

    This paper presents a detailed discussion of the experimental analysis of the external noise produced by a Chinese high-speed train traveling at different speeds. Based on the delay and sum beam-forming method, a microphone array with 78 microphones was used to measure the external noise produced by the train moving at speeds of up to 390 km/h. The experiment and its analysis showed that the main noise produced by the train originates in three areas: the wheel/rail system (or bogies), the pantograph, and the inter-coach gaps of the train. The frequency characteristics and sound exposure level (SEL) of these main sources were analyzed for different speeds. In the range of 5000 Hz, the SELs of the three main noise sources are clearly identified. Along the vertical height of the train, as seen from the rail head, the maximum noise levels always occur in the wheel/rail area. At different measurement field points, the predominant noise components of the total noise have different frequencies that vary with the train speed. Furthermore, at the measurement points, the rolling noise has a greater contribution to the total noise than the aerodynamic noise. The experimental results and their corresponding analysis are very useful for the control and reduction of the external noise produced by high-speed trains.

  3. Dynamic Analysis of the High Speed Train and Slab Track Nonlinear Coupling System with the Cross Iteration Algorithm

    Directory of Open Access Journals (Sweden)

    Xiaoyan Lei

    2016-01-01

    Full Text Available A model for dynamic analysis of the vehicle-track nonlinear coupling system is established by the finite element method. The whole system is divided into two subsystems: the vehicle subsystem and the track subsystem. Coupling of the two subsystems is achieved by equilibrium conditions for wheel-to-rail nonlinear contact forces and geometrical compatibility conditions. To solve the nonlinear dynamics equations for the vehicle-track coupling system, a cross iteration algorithm and a relaxation technique are presented. Examples of vibration analysis of the vehicle and slab track coupling system induced by China’s high speed train CRH3 are given. In the computation, the influences of linear and nonlinear wheel-to-rail contact models and different train speeds are considered. It is found that the cross iteration algorithm and the relaxation technique have the following advantages: simple programming; fast convergence; shorter computation time; and greater accuracy. The analyzed dynamic responses for the vehicle and the track with the wheel-to-rail linear contact model are greater than those with the wheel-to-rail nonlinear contact model, where the increasing range of the displacement and the acceleration is about 10%, and the increasing range of the wheel-to-rail contact force is less than 5%.

  4. High-Speed Rail Train Timetabling Problem: A Time-Space Network Based Method with an Improved Branch-and-Price Algorithm

    Directory of Open Access Journals (Sweden)

    Bisheng He

    2014-01-01

    Full Text Available A time-space network based optimization method is designed for high-speed rail train timetabling problem to improve the service level of the high-speed rail. The general time-space path cost is presented which considers both the train travel time and the high-speed rail operation requirements: (1 service frequency requirement; (2 stopping plan adjustment; and (3 priority of train types. Train timetabling problem based on time-space path aims to minimize the total general time-space path cost of all trains. An improved branch-and-price algorithm is applied to solve the large scale integer programming problem. When dealing with the algorithm, a rapid branching and node selection for branch-and-price tree and a heuristic train time-space path generation for column generation are adopted to speed up the algorithm computation time. The computational results of a set of experiments on China’s high-speed rail system are presented with the discussions about the model validation, the effectiveness of the general time-space path cost, and the improved branch-and-price algorithm.

  5. Passenger comfort on high-speed trains: effect of tunnel noise on the subjective assessment of pressure variations.

    Science.gov (United States)

    Sanok, Sandra; Mendolia, Franco; Wittkowski, Martin; Rooney, Daniel; Putzke, Matthias; Aeschbach, Daniel

    2015-01-01

    When passing through a tunnel, aerodynamic effects on high-speed trains may impair passenger comfort. These variations in atmospheric pressure are accompanied by transient increases in sound pressure level. To date, it is unclear whether the latter influences the perceived discomfort associated with the variations in atmospheric pressure. In a pressure chamber of the DLR-Institute of Aerospace Medicine, 71 participants (M = 28.3 years ± 8.1 SD) rated randomised pressure changes during two conditions according to a crossover design. The pressure changes were presented together with tunnel noise such that the sound pressure level was transiently elevated by either +6 dB (low noise condition) or +12 dB (high noise condition) above background noise level (65 dB(A)). Data were combined with those of a recent study, in which identical pressure changes were presented without tunnel noise (Schwanitz et al., 2013, 'Pressure Variations on a Train - Where is the Threshold to Railway Passenger Discomfort?' Applied Ergonomics 44 (2): 200-209). Exposure-response relationships for the combined data set comprising all three noise conditions show that pressure discomfort increases with the magnitude and speed of the pressure changes but decreases with increasing tunnel noise. Practitioner Summary: In a pressure chamber, we systematically examined how pressure discomfort, as it may be experienced by railway passengers, is affected by the presence of tunnel noise during pressure changes. It is shown that across three conditions (no noise, low noise (+6 dB), high noise (+12 dB)) pressure discomfort decreases with increasing tunnel noise.

  6. Random fields and associated statistical inverse problems for uncertainty quantification : application to railway track geometries for high-speed trains dynamical responses and risk assessment

    OpenAIRE

    Perrin, Guillaume

    2013-01-01

    High speed trains are currently meant to run faster and to carry heavier loads, while being less energy consuming and still ensuring the safety and comfort certification criteria. In order to optimize the conception of such innovative trains, a precise knowledge of the realm of possibilities of track conditions that the train is likely to be confronted to during its life cycle is necessary. Simulation has therefore a big to play in this context. However, to face these challenges, it has to be...

  7. Analysis of torque transmitting behavior and wheel slip prevention control during regenerative braking for high speed EMU trains

    Science.gov (United States)

    Xu, Kun; Xu, Guo-Qing; Zheng, Chun-Hua

    2016-04-01

    The wheel-rail adhesion control for regenerative braking systems of high speed electric multiple unit trains is crucial to maintaining the stability, improving the adhesion utilization, and achieving deep energy recovery. There remain technical challenges mainly because of the nonlinear, uncertain, and varying features of wheel-rail contact conditions. This research analyzes the torque transmitting behavior during regenerative braking, and proposes a novel methodology to detect the wheel-rail adhesion stability. Then, applications to the wheel slip prevention during braking are investigated, and the optimal slip ratio control scheme is proposed, which is based on a novel optimal reference generation of the slip ratio and a robust sliding mode control. The proposed methodology achieves the optimal braking performance without the wheel-rail contact information. Numerical simulation results for uncertain slippery rails verify the effectiveness of the proposed methodology.

  8. Changes in body surface temperature during speed endurance work-out in highly-trained male sprinters

    Science.gov (United States)

    Korman, Paweł; Straburzyńska-Lupa, Anna; Kusy, Krzysztof; Kantanista, Adam; Zieliński, Jacek

    2016-09-01

    The mechanism of thermoregulatory adaptation to exercise cannot yet be fully explained, however, infrared thermography (IRT) seems to have potential for monitoring physiological changes during exercise and training. It is a non-contact and easy to use technology to measure heat radiation from the body surface. The objective of the study was to examine the temperature changes over time on lower limbs in sprinters during speed endurance training session. Eight sprinters, specialized in distances 100 m and 200 m, aged 21-29 years, members of the Polish national team, were evaluated during an outdoor speed endurance work-out. Their track session comprised of warm-up, specific drills for sprinting technique, and speed endurance exercise. The surface temperature of lower limbs was measured and thermal images were taken using infrared camera after each part of the session. The speed endurance training session brought about specific time course of body surface (legs) temperature. The warm-up induced a significant decline in surface temperature by ∼2.5 °C, measured both on the front and back of lower limbs (p Body surface temperature may help identify an individual optimal time to terminate warm up and start the main part of the training session. It may also be useful for the assessment of muscle activity symmetry in cyclical activities, such as sprint running. This is of particular relevance when a training session is performed outdoors in changeable weather conditions.

  9. Time-frequency processing of track irregularities in high-speed train

    Science.gov (United States)

    Ning, Jing; Lin, Jianhui; Zhang, Bing

    2016-01-01

    Track irregularities are the main source of vehicle vibration. With the increase in the speed, the track irregularities have become a more significant issue of concerned. The axle box acceleration signals can be obtained for analyzing the track irregularities, but the signals are usually non-stationary and signal processing results are not normally satisfied with the ordinary way. Thus, time-frequency distribution analysis is proposed to use in this study. To minimize the cross-terms, a new method based on Empirical Mode Decomposition (EMD) and Cohen's class distribution has been developed and advanced. This approach has been tested with three typical simulation signals and then applied to analyze the track irregularities. The result is consistent with the result from track inspection cars. This indicates this new algorithm is suitable for analyzing the track irregularities. It can be applied in rail irregularity measurement to compensate some shortages of the track inspection cars.

  10. A combined simulation of high speed train permanent magnet traction system using dynamic reluctance mesh model and Simulink

    Institute of Scientific and Technical Information of China (English)

    Xiao-yan HUANG; Jian-cheng ZHANG; Chuan-ming SUN; Zhang-wen HUANG; Qin-fen LU; You-tong FANG; Li YAO

    2015-01-01

    This paper presents a combined dynamic parameter model (DPM) of a high speed train permanent magnet traction system using a dynamic reluctance mesh model and MATLAB Simulink. First, the dynamic reluctance model of the permanent magnet synchronous motor is introduced. Then the combined models of the traction system underid=0 and maximum torque per ampere control are built.Simulations using both constant parameter models and DPM models are carried out. The speed and torque characteristics are obtained. The results confirm that the DPM model provides higher accuracy without much sacrifice of time consumption or computation resource.%目的:提出基于动态磁网络和Simulink的高速铁路牵引传动系统的动态参数模型,提高高速铁路牵引传动系统仿真分析的准确度。  方法:将动态磁网络计算得出的动态参数Ld,Lq等以查表的形式嵌入 Simulink 模型,有效地实现动态参数。  结论:该动态参数模型能在不显著增加仿真运算量和仿真时间的条件下有效地提高计算的准确度。

  11. Use of cardio-diagnostics of D&K-TEST for individualizations of training process of skilled short track speed skaters high qualification

    Directory of Open Access Journals (Sweden)

    Kygayevskiy S.A.

    2009-10-01

    Full Text Available In the article possibilities of individualization of training process of short track speed skaters high qualification are resulted on the basis of influence of application of loadings of different orientation on the indexes of cardio-diagnostics of D&K-TEST. The influences of loadings of different physiological and metabolic orientation given about efficiency are resulted on the level of functional preparedness of short track speed skaters of high qualification.

  12. 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.

  13. A full-spectrum analysis of high-speed train interior noise under multi-physical-field coupling excitations

    Science.gov (United States)

    Zheng, Xu; Hao, Zhiyong; Wang, Xu; Mao, Jie

    2016-06-01

    High-speed-railway-train interior noise at low, medium, and high frequencies could be simulated by finite element analysis (FEA) or boundary element analysis (BEA), hybrid finite element analysis-statistical energy analysis (FEA-SEA) and statistical energy analysis (SEA), respectively. First, a new method named statistical acoustic energy flow (SAEF) is proposed, which can be applied to the full-spectrum HST interior noise simulation (including low, medium, and high frequencies) with only one model. In an SAEF model, the corresponding multi-physical-field coupling excitations are firstly fully considered and coupled to excite the interior noise. The interior noise attenuated by sound insulation panels of carriage is simulated through modeling the inflow acoustic energy from the exterior excitations into the interior acoustic cavities. Rigid multi-body dynamics, fast multi-pole BEA, and large-eddy simulation with indirect boundary element analysis are first employed to extract the multi-physical-field excitations, which include the wheel-rail interaction forces/secondary suspension forces, the wheel-rail rolling noise, and aerodynamic noise, respectively. All the peak values and their frequency bands of the simulated acoustic excitations are validated with those from the noise source identification test. Besides, the measured equipment noise inside equipment compartment is used as one of the excitation sources which contribute to the interior noise. Second, a full-trimmed FE carriage model is firstly constructed, and the simulated modal shapes and frequencies agree well with the measured ones, which has validated the global FE carriage model as well as the local FE models of the aluminum alloy-trim composite panel. Thus, the sound transmission loss model of any composite panel has indirectly been validated. Finally, the SAEF model of the carriage is constructed based on the accurate FE model and stimulated by the multi-physical-field excitations. The results show

  14. Application of the speed-duration relationship to normalize the intensity of high-intensity interval training.

    Directory of Open Access Journals (Sweden)

    Carrie Ferguson

    Full Text Available The tolerable duration of continuous high-intensity exercise is determined by the hyperbolic Speed-tolerable duration (S-tLIM relationship. However, application of the S-tLIM relationship to normalize the intensity of High-Intensity Interval Training (HIIT has yet to be considered, with this the aim of present study. Subjects completed a ramp-incremental test, and series of 4 constant-speed tests to determine the S-tLIM relationship. A sub-group of subjects (n = 8 then repeated 4 min bouts of exercise at the speeds predicted to induce intolerance at 4 min (WR4, 6 min (WR6 and 8 min (WR8, interspersed with bouts of 4 min recovery, to the point of exercise intolerance (fixed WR HIIT on different days, with the aim of establishing the work rate that could be sustained for 960 s (i.e. 4×4 min. A sub-group of subjects (n = 6 also completed 4 bouts of exercise interspersed with 4 min recovery, with each bout continued to the point of exercise intolerance (maximal HIIT to determine the appropriate protocol for maximizing the amount of high-intensity work that can be completed during 4×4 min HIIT. For fixed WR HIIT tLIM of HIIT sessions was 399±81 s for WR4, 892±181 s for WR6 and 1517±346 s for WR8, with total exercise durations all significantly different from each other (P0.050. However, there was significantly less high-intensity work completed during bouts 2 (153.5±40. 9 m, 3 (136.9±38.9 m, and 4 (136.7±39.3 m, compared with bout 1 (264.9±58.7 m; P>0.050. These data establish that WR6 provides the appropriate work rate to normalize the intensity of HIIT between subjects. Maximal HIIT provides a protocol which allows the relative contribution of the work rate profile to physiological adaptations to be considered during alternative intensity-matched HIIT protocols.

  15. Application of the speed-duration relationship to normalize the intensity of high-intensity interval training.

    Science.gov (United States)

    Ferguson, Carrie; Wilson, John; Birch, Karen M; Kemi, Ole J

    2013-01-01

    The tolerable duration of continuous high-intensity exercise is determined by the hyperbolic Speed-tolerable duration (S-tLIM) relationship. However, application of the S-tLIM relationship to normalize the intensity of High-Intensity Interval Training (HIIT) has yet to be considered, with this the aim of present study. Subjects completed a ramp-incremental test, and series of 4 constant-speed tests to determine the S-tLIM relationship. A sub-group of subjects (n = 8) then repeated 4 min bouts of exercise at the speeds predicted to induce intolerance at 4 min (WR4), 6 min (WR6) and 8 min (WR8), interspersed with bouts of 4 min recovery, to the point of exercise intolerance (fixed WR HIIT) on different days, with the aim of establishing the work rate that could be sustained for 960 s (i.e. 4×4 min). A sub-group of subjects (n = 6) also completed 4 bouts of exercise interspersed with 4 min recovery, with each bout continued to the point of exercise intolerance (maximal HIIT) to determine the appropriate protocol for maximizing the amount of high-intensity work that can be completed during 4×4 min HIIT. For fixed WR HIIT tLIM of HIIT sessions was 399±81 s for WR4, 892±181 s for WR6 and 1517±346 s for WR8, with total exercise durations all significantly different from each other (PHIIT, there was no difference in tLIM of each of the 4 bouts (Bout 1: 229±27 s; Bout 2: 262±37 s; Bout 3: 235±49 s; Bout 4: 235±53 s; P>0.050). However, there was significantly less high-intensity work completed during bouts 2 (153.5±40. 9 m), 3 (136.9±38.9 m), and 4 (136.7±39.3 m), compared with bout 1 (264.9±58.7 m; P>0.050). These data establish that WR6 provides the appropriate work rate to normalize the intensity of HIIT between subjects. Maximal HIIT provides a protocol which allows the relative contribution of the work rate profile to physiological adaptations to be considered during alternative intensity-matched HIIT protocols.

  16. A framework for categorizing risks in High Speed Train (HST projects: the example of the first HST in Brazil

    Directory of Open Access Journals (Sweden)

    Viviane GRUBISIC

    2015-12-01

    Full Text Available High Speed Train projects are exposed to risks of different natures, such as: low participation of private companies in the new railways construction, lack of skilled labor, high technology not available in the internal market, high costs with land acquisition, among others. Such risks if not managed properly can become real problems and compromise the achievement of the project objectives. The risk identification is the process of collection and description of events that can have negative effects on the project. This process should consider the project uncertainty elements in order to generate specific results. In the case of HST projects, examples of uncertainty elements are: politics, economy, environment, human resources and technology. Therefore, this study aims to present a framework for categorizing risks to be used in HST projects. Also, for each category proposed some risk examples are suggested. An overview of the first Brazil HST project is showed and the risk framework is proposed. A discussion on the risks in the first Brazil HST project are presented followed by final conclusions.

  17. High-speed train bogie technology research%高速列车转向架技术研究

    Institute of Scientific and Technical Information of China (English)

    赵明花; 梁树林; 宋春元

    2015-01-01

    ,take a great deal dynamic stress test,use the test data analysis maintenance vehicle operating cycle,different climatic conditions,different line conditions on the ballastless track of China,setup China high-speed train load spectrum. Through system integration of the structure design,suspension,trans-mission,brake,wheel rail noise,structure welding and so on,the high-speed train bogie technol-ogy system was founded.

  18. Dynamic unbalance detection of cardan shaft in high-speed train based on EMD-SVD-NHT

    Institute of Scientific and Technical Information of China (English)

    丁建明; 林建辉; 何刘; 赵洁

    2015-01-01

    Contrary to the aliasing defect between the adjacent intrinsic model functions (IMFs) existing in empirical model decomposition (EMD), a new method of detecting dynamic unbalance with cardan shaft in high-speed train was proposed by applying the combination between EMD, Hankel matrix, singular value decomposition (SVD) and normalized Hilbert transform (NHT). The vibration signals of gimbal installed base were decomposed through EMD to get different IMFs. The Hankel matrix constructed through the single IMF was orthogonally executed through SVD. The critical singular values were selected to reconstruct vibration signs on the basis of the key stack of singular values. Instantaneous frequencys (IFs) of reconstructed vibration signs were applied to detect dynamic unbalance with shaft and eliminated clutter spectrum caused by the aliasing defect between the adjacent IMFs, which highlighted the failure characteristics. The method was verified by test data in the unbalance condition of dynamic cardan shaft. The results show that the method effectively detects the fault vibration characteristics caused by cardan shaft dynamic unbalance and extracts the nature vibration features. With comparison to the traditional EMD-NHT, clarity and failure characterization force are significantly improved.

  19. Control entropy identifies differential changes in complexity of walking and running gait patterns with increasing speed in highly trained runners

    Science.gov (United States)

    McGregor, Stephen J.; Busa, Michael A.; Skufca, Joseph; Yaggie, James A.; Bollt, Erik M.

    2009-06-01

    Regularity statistics have been previously applied to walking gait measures in the hope of gaining insight into the complexity of gait under different conditions and in different populations. Traditional regularity statistics are subject to the requirement of stationarity, a limitation for examining changes in complexity under dynamic conditions such as exhaustive exercise. Using a novel measure, control entropy (CE), applied to triaxial continuous accelerometry, we report changes in complexity of walking and running during increasing speeds up to exhaustion in highly trained runners. We further apply Karhunen-Loeve analysis in a new and novel way to the patterns of CE responses in each of the three axes to identify dominant modes of CE responses in the vertical, mediolateral, and anterior/posterior planes. The differential CE responses observed between the different axes in this select population provide insight into the constraints of walking and running in those who may have optimized locomotion. Future comparisons between athletes, healthy untrained, and clinical populations using this approach may help elucidate differences between optimized and diseased locomotor control.

  20. Optimization of Fixed Microphone Array in High Speed Train Noises Identification Based on Far-Field Acoustic Holography

    Directory of Open Access Journals (Sweden)

    Rujia Wang

    2017-01-01

    Full Text Available Acoustical holography has been widely applied for noise sources location and sound field measurement. Performance of the microphones array directly determines the sound source recognition method. Therefore, research is very important to the performance of the microphone array, its array of applications, selection, and how to design instructive. In this paper, based on acoustic holography moving sound source identification theory, the optimization method is applied in design of the microphone array, we select the main side lobe ratio and the main lobe area as the optimization objective function and then put the optimization method use in the sound source identification based on holography, and finally we designed this paper to optimize microphone array and compare the original array of equally spaced array with optimization results; by analyzing the optimization results and objectives, we get that the array can be achieved which is optimized not only to reduce the microphone but also to change objective function results, while improving the far-field acoustic holography resolving effect. Validation experiments have showed that the optimization method is suitable for high speed trains sound source identification microphone array optimization.

  1. 高速列车空气阻力测量分析方法%Measurement Method for the Air Resistance of High Speed Train

    Institute of Scientific and Technical Information of China (English)

    康熊; 曾宇清; 张波

    2012-01-01

    To decouple air resistance and other resistance from the resistance of high speed train, based on the assumption that air resistance is independent of train mass while other resistance is proportional to train mass, correlation equations were built among air resistance, other resistance, train mass and speed u-sing the resistance measurement data of idling condition under the full and empty load of train. Such restrictions as zero crossing point and monotone increasing were imposed on air resistance term, and accordingly the formula was obtained for calculating air resistance and other resistance of high speed train. The air resistance of CRH3 EMU was analyzed using speed-acceleration fitting method and time-speed curve based train resistance optimization method. The results show that, based on the engineering assumption that air resistance is independent of train mass while other resistance is proportional to train mass, can a-chieve the decoupling of the air resistance from other resistance and coupling analysis. Both the quadratic term and linear term related to train speed are included in the equations for the air resistance and other resistance of CRH3 EMU. However, the linear term related to train speed in air resistance equation is rather small and can be ignored. For high speed train, train total resistance can describe the characteristics of train's resistance more accurately than unit basic resistance.%为从高速列车阻力中分离出空气阻力和其他阻力,基于空气阻力与列车质量基本无关、其他阻力与列车质量成正比的假设,以及列车满载和空载状态下的惰行工况阻力测量数据,建立列车空气阻力、其他阻力、质量和速度的关联方程组,并对空气阻力项施加过零点且单调递增的约束,从而得到高速列车的空气阻力及其他阻力的计算公式;然后采用速度加速度拟合和基于时间一速度曲线的列车阻力优化2种方法对CRH3型高速动车组的空

  2. High Speed Video Insertion

    Science.gov (United States)

    Janess, Don C.

    1984-11-01

    This paper describes a means of inserting alphanumeric characters and graphics into a high speed video signal and locking that signal to an IRIG B time code. A model V-91 IRIG processor, developed by Instrumentation Technology Systems under contract to Instrumentation Marketing Corporation has been designed to operate in conjunction with the NAC model FHS-200 High Speed Video Camera which operates at 200 fields per second. The system provides for synchronizing the vertical and horizontal drive signals such that the vertical sync precisely coincides with five millisecond transitions in the IRIG time code. Additionally, the unit allows for the insertion of an IRIG time message as well as other data and symbols.

  3. Effects of Heart Rate vs. Speed-Based High Intensity Interval Training on Aerobic and Anaerobic Capacity of Female Soccer Players

    Directory of Open Access Journals (Sweden)

    Hamid Arazi

    2017-08-01

    Full Text Available The purpose of this study was to compare the effects of two types of high-intensity interval training (HIIT programs on aerobic and anaerobic capacity of female soccer players. Regional-level female athletes were randomly divided into heart rate-based HIIT (n = 8; age 23.4 ± 1.1 year and speed-based HIIT groups (n = 8; age 23.4 ± 1.3 year. Athletes trained three days per week for six weeks. Before and after training, each athlete’s performance was assessed directly through the Hoff test, 30-15 Intermittent Fitness Test (VIFT, and repeated-sprint ability test (RAST; maximal oxygen consumption (VO2max, power and fatigue were estimated indirectly. Both experimental groups improved power, fatigue index and VO2max after training (p < 0.05. It was noteworthy that the speed-based group had greater gains in minimal power (effect size (ES: 3.99 vs. 0.75, average power (ES: 2.23 vs. 0.33, and fatigue index (ES: 2.53 vs. 0.17 compared to heart rate-based group (p < 0.05. In conclusion, both heart rate-based and speed-based HIIT induced meaningful improvements in power, VO2max, and fatigue index in female soccer players, although the speed-based HIIT group achieved greater gains in power and fatigue index compared to the heart rate-based group.

  4. High speed multiphoton imaging

    Science.gov (United States)

    Li, Yongxiao; Brustle, Anne; Gautam, Vini; Cockburn, Ian; Gillespie, Cathy; Gaus, Katharina; Lee, Woei Ming

    2016-12-01

    Intravital multiphoton microscopy has emerged as a powerful technique to visualize cellular processes in-vivo. Real time processes revealed through live imaging provided many opportunities to capture cellular activities in living animals. The typical parameters that determine the performance of multiphoton microscopy are speed, field of view, 3D imaging and imaging depth; many of these are important to achieving data from in-vivo. Here, we provide a full exposition of the flexible polygon mirror based high speed laser scanning multiphoton imaging system, PCI-6110 card (National Instruments) and high speed analog frame grabber card (Matrox Solios eA/XA), which allows for rapid adjustments between frame rates i.e. 5 Hz to 50 Hz with 512 × 512 pixels. Furthermore, a motion correction algorithm is also used to mitigate motion artifacts. A customized control software called Pscan 1.0 is developed for the system. This is then followed by calibration of the imaging performance of the system and a series of quantitative in-vitro and in-vivo imaging in neuronal tissues and mice.

  5. The motion simulation of high-speed train%高速列车运动仿真可视化建模研究

    Institute of Scientific and Technical Information of China (English)

    吕希奎; 周小平; 贾晓秋

    2013-01-01

    The three-dimensional dynamic simulation model based on varying parameters is established for the CRH high-speed train, and the real-time transfer and assembly of various train element models during the process of motion are achieved. A high-speed train movement simulation system is developed using Visual C++ 6.0, OpenGL 3D graphics library and the Oracle Database. A comprehensive integrated simulation system between High-speed train movement and three-dimensional line design is established. The experiments show that good simulation results are obtained.%以CRH系列高速列车为研究对象,建立了基于变参数的列车三维动态仿真模型,实现了多种列车单元模型在运动过程中的实时调入和装配,满足了高速列车运动仿真多样性的要求.采用Visual C++ 6.0、OpenGL三维图形库和Oracle数据库开发完成高速列车运动仿真系统,实现高速列车运动仿真可视化建模以及与线路设计之间的有效集成.通过实际应用,取得了较好的仿真效果.

  6. Effects of different doses of high-speed resistance training on physical performance and quality of life in older women: a randomized controlled trial

    Science.gov (United States)

    Ramirez-Campillo, Rodrigo; Diaz, Daniela; Martinez-Salazar, Cristian; Valdés-Badilla, Pablo; Delgado-Floody, Pedro; Méndez-Rebolledo, Guillermo; Cañas-Jamet, Rodrigo; Cristi-Montero, Carlos; García-Hermoso, Antonio; Celis-Morales, Carlos; Moran, Jason; Buford, Thomas W; Rodriguez-Mañas, Leocadio; Alonso-Martinez, Alicia M; Izquierdo, Mikel

    2016-01-01

    Objective This study aimed to compare the effects of two frequencies of high-speed resistance training (HSRT) on physical performance and quality of life of older women. Methods A total of 24 older women participated in a 12-week HSRT program composed of either two or three sessions/week (equated for volume and intensity). Women were randomized into three arms: a control group (CG, n=8), a resistance training group performing two sessions/week (RT2, n=8), and a resistance training group performing three sessions/week (RT3, n=8). The training program for both experimental groups included exercises that required high-speed concentric muscle actions. Results No baseline differences were observed among groups. Compared with the CG, both training groups showed similar small to moderate improvements (P<0.05) in muscle strength, power, functional performance, balance, and quality of life. Conclusion These results suggest that equated for volume and intensity, two and three training sessions/week of HSRT are equally effective for improving physical performance and quality of life of older women. PMID:28008239

  7. 高速列车车头的气动噪声数值分析%Numerical Analysis on Aerodynamic Noise of the High-speed Train Head

    Institute of Scientific and Technical Information of China (English)

    刘加利; 张继业; 张卫华

    2011-01-01

    Along with the raising of the train speed, aerodynamic noise of the high-speed train are generated more and more significantly and their reduction has become one of the key factors to control noises of the highspeed train. In this paper, aerodynamic noise radiated from the high-speed train head surface are analyzed numerically. The mathematical and physical models of the three dimensional flow field of the high-speed train are established and the external steady and unsteady flow fields of the high-speed train are calculated by using the standard k-e turbulence model and large eddy simulation (LES) respectively. On the basis of the steady flow field, aerodynamic noise sources on the car body surface of the high-speed train are calculated by using the broadband noise source model. On the basis of the unsteady flow field, the time domain and frequency domain characteristics of fluctuating pressures on the car body surface are analyzed. The far-field aerodynamic noise of the high-speed train are calculated by applying the Lighthill acoustic analogue theory and the time domain and frequency domain characteristics of aerodynamic noise in the far-field are analyzed. The computational research is significant to study and control of aerodynamic noise of the high-speed train.%随着列车运行速度的提高,列车气动噪声变得越来越明显,降低气动噪声已成为控制高速列车噪声的关键之一.本文对高速列车车头气动噪声进行数值分析.首先,建立高速列车三维绕流流场的数学物理模型,分别利用标准k-ε湍流模型和大涡模拟计算高速列车的外部稳态和瞬态流场.然后,基于稳态流场,利用宽频带噪声源模型计算高速列车车身表面气动噪声源;基于瞬态流场,分析车身表面脉动压力的时域及频域特性;利用Lighthill声学比拟理论,计算高速列车远场气动噪声,分析远场气动噪声的时域及频域特性.本文对研究和控制高速列车气动噪声具有一定意义.

  8. High speed flywheel

    Science.gov (United States)

    McGrath, Stephen V.

    1991-01-01

    A flywheel for operation at high speeds utilizes two or more ringlike coments arranged in a spaced concentric relationship for rotation about an axis and an expansion device interposed between the components for accommodating radial growth of the components resulting from flywheel operation. The expansion device engages both of the ringlike components, and the structure of the expansion device ensures that it maintains its engagement with the components. In addition to its expansion-accommodating capacity, the expansion device also maintains flywheel stiffness during flywheel operation.

  9. Calculation method of cross wind security domain for high-speed train%高速列车侧风安全域计算方法

    Institute of Scientific and Technical Information of China (English)

    崔涛; 张卫华

    2011-01-01

    Based on parameter transmission,solution to control and dynamic mesh techniques,the cross wind fluid dynamics model and the multi-body system dynamics model of high-speed train were established.By collaboratively simulating the external flow field and system response of train,the stable attitudes and aerodynamic loads under different cross wind environments were obtained.The running safety indexes were studied,the critical speeds of running safety under different cross wind environments were analyzed,and the security domain was defined.Calculation result indicates that with the increases of train speed and cross wind strength,the transfinite phenomena of wheel unloading rate,derailment coefficient and lateral wheelset force appear successively.While train speed is less than 300 km·h-1,all wheelsets of leading vehicle almost have upwind migration.While train speed is 300 km·h-1 and cross wind speed is 30 m·s-1,and train speed is 350 km·h-1 and cross wind speed is more than 25 m·s-1,the first and second wheelsets have downwind migration,the third and fourth wheelsets have upwind migration.The higher train speed is,the lower the cross wind resistance ability is,and the sensitivity of train critical speed on cross wind strength will increase.2 tabs,13 figs,14 refs.%使用参数传递、求解控制以及动态网格技术,建立了侧风流体动力学模型和高速列车多体动力学模型,通过对列车外流场和系统响应进行协同仿真,获得不同侧风环境下列车的稳定姿态和气动载荷,研究了列车运行的安全性指标,分析了不同侧风环境下列车安全运行的临界速度,确定了列车的侧风作用安全域。计算结果表明:随着列车运行速度和侧风强度的增大,轮重减载率、脱轨系数和轮轴横向力依次出现超限现象;当列车运行速度小于300 km.h-1时,列车头车所有轮对均逆风向偏移;当列车运行速度为300 km.h-1且侧风风速为30 m.s-1

  10. 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.

  11. Repression and Criminalization of the Ecologist Movement in the Basque Country: the Case of the High Speed Train Project

    Directory of Open Access Journals (Sweden)

    Carlos Alonso Cidad

    2014-01-01

    Full Text Available This article offers an analysis of the process of criminalization, which, in the authors’ opinion, the Basque Ecologist Movement (BEM has suffered in its fight against the High Speed Train (HST. The text is structured in five sections. The initial section highlights the main characteristics of the BEM from its origins to the present, indicating the importance in its development of the Basque national question and political violence on one side, and a combined discourse that is at once local and global on the other. The second section provides data referring to the HST project, indicating its political and socio-economic impacts, while the third section is dedicated to clarifying the main identity features and lines of action of the anti-HST movement. The fourth section shows both the repertory of collective action of the opponents of the HST and the policies of repression and criminalization exercised against them. The fifth and final section is situated in today’s new political cycle, which follows the end of ETA’s armed activity and sets out possible future scenarios. Rather than an academic article consisting of intellectual reflection, this article is intended as a political testimony of the long struggle of this social movement, involving 20 years of ecologist activism, a struggle that continues today, since the infrastructure project is still in force, although the conflict is little known at the international level. Este artículo ofrece un análisis del proceso de criminalización, que, en opinión de los autores, el Movimiento Ecologista Vasco ha sufrido en su lucha contra el Tren de Alta Velocidad (TAV. El texto se estructura en cinco partes. En la primera se destacan las principales características del Movimiento Ecologista Vasco, desde sus orígenes hasta la actualidad, subrayando la importancia en su desarrollo de la cuestión nacional vasca y la violencia política por un lado, y por otro, un discurso combinado local y

  12. Effect of high-speed treadmill training with a body weight support system in a sport acceleration program with female soccer players.

    Science.gov (United States)

    Johnson, A Wayne; Eastman, Carie S; Feland, Jeffery Brent; Mitchell, Ulrike H; Mortensen, Bartley Brett; Eggett, Dennis

    2013-06-01

    Maximum running speed and acceleration are essential components in many sports. The identification of specific training protocols to maximize sprint speed would be useful knowledge for coaches and players. The purpose of this study was to determine the effect of a high-speed treadmill (HST) with the use of a body weight support (BWS) system in a 6-week sport acceleration program (SAP) on female soccer athlete's 40-yard sprint time and maximal isometric knee flexor and extensor strength. Two treatment groups and one control group were created. Both treatment groups participated in a 12-session SAP. The first treatment group (n = 12) used a BWS system while running on a HST; the second group (n = 12) used a standard treadmill (ST) with no BWS system. The participants of the control group (n = 8), NT, did not participate in a sports acceleration program and did not alter their exercise routines outside of the study. An analysis of covariance was performed using baseline measures as the covariate. The 40-yard sprint times for both treatment groups were shown to improve significantly compared with the control group (p 0.05). Participants in the ST group had a much higher rate (66%) of shin splints and foot pain throughout the study than those in the HST (8%) and NT (0%) groups. These results can help high school coaches and athletes determine the optimal treadmill training regime.

  13. Review of active noise control technology in high speed train%高速列车车厢内噪声主动控制技术综述

    Institute of Scientific and Technical Information of China (English)

    靳光磊; 刘永明

    2011-01-01

    传统的高速列车噪声控制多采用隔音、减振等被动的降噪方法,仅对中高频噪声的控制有效,无法满足时速300 km以上高速列车的噪声控制要求.而主动噪声控制技术通过有目的地产生一个次级声信号来消弭低频噪声,适于高速列车车厢内噪声控制.无论次级声源控制还是次级力源控制,都要增强系统的可靠性和鲁棒性,而宽带噪声控制的多通道自适应噪声主动控制技术将会成为该领域的研究热点.%The traditional method of high-speed train noise control use passive noise reduction methods, such as sound insulation,vibration reduction and so on,but only the high-frequency noise control effective, which can't meet the requirements of more than 300 km/h high-speed train noise control. In order to eliminate low-frequency noise purposely, the active noise control for high-speed trains generate the secondary acoustic signal. Whether the secondary sound source control or secondary force source of control,the noise control methods should enhance system reliability and robustness, and the broadband multi-channel adaptive active noise control technology will become the research focus.

  14. Reducing the Drag and Damage of a High-Speed Train by Analyzing and Optimizing its Boundary Layer Separation and Roll-up into Wake Vortices

    Science.gov (United States)

    Jiang, Chung-Hsiang; Marcus, Philip

    2012-11-01

    We present numerical calculations of the boundary layers and shed wake vortices behind several aerodynamic bodies and generic models of high-speed trains. Our calculations illustrate new visual diagnostics that we developed that clearly show where the separation of a boundary layer occurs and where, how, and with what angles (with respect to the stream-wise direction) the wake vortices form. The calculations also illustrate novel 3D morphing and mesh ``pushing and pulling'' techniques that allow us to change the shapes of aerodynamic bodies and models in a controlled and automated manner without spurious features appearing. Using these tools we have examined the patterns of the shed vortices behind generic bodies and trains and correlated them with the changes in the drag as well as with the effects of the shed vortices on the environment. In particular, we have applied these techniques to the end car of a next-generation, high-speed train in order to minimize the drag and to minimize the adverse effects of the shed vortices on the track ballast.

  15. Contraception. Slow train gathers speed.

    Science.gov (United States)

    Hampton, N; Kubba, A

    The otherwise slow pace of contraceptive research developments has recently quickened, with new products developed, more on the way, and encouraging new data emerging about existing methods. While the 1995 UK pill scare called attention to a differential in the risk of venous thromboembolism (VTE) between pills containing levonorgestrel or norethisterone and those containing desogestrel or gestodene, there is only an extremely small level of excess mortality attributable to third-generation progestogens, less than 2 per million women per year. Tentative evidence suggests that pills with less anti-estrogenic progestogens are neutral with regard to coronary artery disease. The pill remains extremely safe for healthy young women, although additional research with larger numbers of participants is warranted. Salient research findings are that the combined oral contraceptive pill may protect against colon cancer, the pill appears to offer no protection against bone fractures, new products contain less estrogen and have a shortened pill-free interval, a WHO paper showed no significant association between cardiovascular disease and the use of oral or injectable progestogens, a UK study showed no correlation between bone density and plasma estrogen concentrations among long-term users of depot medroxyprogesterone acetate, and a WHO controlled trial found a progestogen-only method of emergency contraception to be considerably more effective in preventing expected pregnancies than the Yuzpe regimen. The T 380 copper IUD provides very high protection against intrauterine and extrauterine pregnancies for 10 years and is now available in an improved inserting mechanism, the Mirena levonorgestrel-releasing IUD system is now licensed for 5 years, and the GyneFIX IUD implant is a frameless device fixed during insertion to the fundal myometrium.

  16. The Effects of Heart Rate Versus Speed-Based High-Intensity Interval Training on Heart Rate Variability in Young Females

    Directory of Open Access Journals (Sweden)

    Maryam Rabbani

    2017-06-01

    Full Text Available Introduction: The aim of this study was to compare the effects of high-intensity interval training (HIT prescription by heart rate (HR-based and running speed (speed-based methods on natural logarithm of the square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals (Ln rMSSD as a measure of heart rate variability (HRV in young female student athletes. Methods: Seventeen female student athletes participated in this study and were divided into HR-based (n=9, age: 16.7 years and speed-based (n=8, age: 16.9 years HIT groups. 30-15 Intermittent Fitness Test was used for the speed-based group to detect the reference maximum speed (VIFT for prescribing the HIT intensity accordingly. Age predicted maximal HR was used for the HR-based group as the reference value. All subjects performed similar training protocol for 5 weeks, except the method of individualizing HIT sessions (2 weekly sessions of HIT=3 sets of 3 minutes work interspersed with 3 minutes passive recovery with the 15-15 seconds format during each working set; either according to 90%-95% of maximal HR or VIFT. Results: HR- and speed-based HIT groups showed the most likely large improvements in Ln rMSSD of +7.9%, 90% confidence limits [CL] (5.9; 10.0; standardized change: +1.75 (1.32; 2.19 and +5.5%, (2.8; 8.3; +1.41 (0.72; 2.09, respectively. In between group analyses, HR-based HIT produced likely a small greater improvement in Ln rMSSD than speed-based HIT (+1.9%, [-5.0; 4.4]; +0.50 [-0.14; 1.14], chances for greater/similar/lower values of 79/17/4. Conclusion: It is concluded that both HIT prescription strategies were effective in Ln rMSSD elevation, but using maximal HR as a reference may elicit higher parasympathetic dominance with small effect in young female student athletes.

  17. Research on Speed Controller Model for High-speed Train Based on Grey Genetic Algorithm%基于灰色遗传的高速列车速度控制器模型研究

    Institute of Scientific and Technical Information of China (English)

    高凡; 张友鹏; 高平

    2012-01-01

    速度控制器是列车自动驾驶系统(ATO)的核心,针对目前尚无研发成熟的速度控制器应用于高速列车的情况,引入灰色系统理论研究高速列车速度控制器模型;在灰色遗传预测模块中,对影响模型精度的λ值提出了基于遗传算法的求解方法.根据列车运行的4个目标设计其适应度函数,并加入先验知识判定对约束条件进行处理,同时建立新陈代谢GM(1,1)模型,在列车运行过程中不断求解新的模型参数a和b,实现模型在线校正,使系统可以进行长期预测;在灰色决策模块中,将高速列车的工况及运行目标转化为决策要素,应用灰靶决策产生最优策略控制列车运行;仿真结果显示了该模型应用于列车自动控速时的有效性和实时性,并使各项运行指标都有所提高.%The speed controller is the core of the automatic train operation (ATO) system. Gray System Theory that designs the high-speed train speed controller model was introduced according to the current circumstance that there is no mature speed controller used in high - speed train, In the grey genetic algorithm prediction module, genetic algorithm was proposed to solve X value which will impact the accuracy of the model. The fitness function was designed according to the four objectives of trains operation, and a priori knowledge of the determination was added to handle the constraint conditions. The new model parameter a and b were solved by the metabolic GM (1, 1) model during trains operating constantly, which achieve model correction on-line and make the system long-term predict. In the gray decision-making model, high-speed train conditions and objectives were transformed into the decision-making elements, and the gray target decision was introduced to make the optimal policy. Simulation verify the effectiveness and real -time performances of the proposed model, and the operation indicators were improved.

  18. 高速列车透射噪声与结构噪声的分离%High speed train transmission noise and structural noise separation

    Institute of Scientific and Technical Information of China (English)

    纳跃跃; 谢翀

    2013-01-01

    高速列车噪声是影响车内旅客舒适度和铁路沿线居民生活质量的重要因素,如何有效的降低噪声是高速列车设计者们所关心的问题之一.研究表明,高速列车的车内噪声由透射噪声与结构噪声组成,如何有效的从车内噪声中分离出这两种噪声成分将为列车的减振降噪设计提供一定的指导作用.本文以高速列车实车噪声数据为研究对象,首先运用多种数字信号处理的方法对高速列车噪声数据进行了分析,总结了高速列车噪声的主要特点;然后通过对列车静止时和运行时的噪声透射情形分别进行建模和分析,指出可以利用车体的频响特性作为反映车体隔声性能的声学参数,并提出了一种计算频响特性的简便算法;最后,利用该算法从实车噪声数据中计算出了车体的频响特性,并在此基础上实现了透射噪声与结构噪声的分离.%High speed train noise level is an important factor with respect to passenger comfort and life quality of residents along the railway.How to attenuate the noise level is an important research direction that train designers care about.Studies show that train interior noise is consist of transmission noise and structural noise.Separating these two kinds of components from their overall observations will provide further guide to high speed train noise reduction design.The research is based on the real-world high speed train noise data.First,data are analyzed by different digital signal processing methods and some basic properties of the train noise signal are concluded.Then,by modeling and analyzing the noise transmission circumstances when train is stationary and moving,train body frequency response is used to measure the noise insulation quality,and an algorithm is proposed to calculate the frequency response conveniently.At last,train body frequency response is calculated according to the real-world train noise data via the proposed algorithm

  19. 轨道梁在磁浮列车以共振速度通过时动力响应分析%DYNAMIC RESPONSE OF GUIDEWAY GIRDERS DUE TO HIGH-SPEED MAGLEV TRAINS MOVING AT RESONANT SPEEDS

    Institute of Scientific and Technical Information of China (English)

    时瑾; 姚忠达; 王英杰

    2012-01-01

    This paper presents the investigation of dynamic response of a guideway subjected to a maglev train moving with very high speeds. By using modal synthesis technology to establish the guideway-pier model, the equations of motion for the maglev train/guideway coupling system are derived and the dynamic response of the train-guideway system are computed using iterative methods. From the numerical studies of a 24m elevated guideway girder under a high-speed maglev train model of TR08, the results indicate increasing moving speeds may result in an amplified response of the guideway, and the second sub-resonance of the first mode of the guideway would be excited as well once the moving speed reaches around 350km/h. Furthermore, when the moving speed of the malgev train is higher than 400kin/h, the response amplitudes of the guideway girder and moving vehicles are both amplified significantly. To avoid possible train-induced resonance of guideway vibration, the first natural frequency of the guideway should be designed to be higher than the characteristic frequency of the maglev vehicle/guideway system, which is equal to the ratio of the designed speed to the carriage length.%该文研究了高速磁浮列车运行引起的轨道梁动力响应问题。采用模态综合技术建立了梁墩体系模型,推导了高速磁浮列车轨道梁运动方程,运用迭代技术求解了列车轨道梁系统动力学方程,计算分析了高速磁浮列车通过24m简支轨道梁引起的动力响应,结果表明:随着运行速度提高,轨道梁动力响应相应提高,在350km/h左右存在一阶二次谐波共振;当列车运行速度超过400km/h时,轨道梁和列车动力响应将被显着放大,为避免轨道梁出现一阶一次共振现象,在设计上,应使轨道梁的一阶自振频率远高于磁浮列车与轨道梁的特征频率(即设计速度与车长比值)。

  20. Measurement System for Dynamic Envelope Curve of High-Speed Train%高速列车动态包络线测量系统

    Institute of Scientific and Technical Information of China (English)

    郭寅; 刘常杰; 邾继贵; 刘刚; 高福来; 叶声华

    2013-01-01

    动态包络线是制定动态限界的主要依据,准确得到动态包络线是车辆设计过程中的一项重要内容,也是安全行车的重要保障.针对当前车辆动态包络线的获取主要通过计算手段这一情况,设计了高速列车动态包络线测量系统.系统基于双目视觉测量原理,利用大功率线激光瞬时光源构造测量特征,通过高速采集、处理、解算能反映列车动态偏移的被测信息,得到高速列车行驶过程中的动态包络线.提出了一种现场系统校准方法,快速、有效地建立双相机之间的位置关系、轨道中心坐标系及其与测量系统坐标系之间的转换关系.实验结果表明,系统测量精度可达±0.5 mm,实现了高速列车动态包络线的真实可靠测量,为高速列车动态限界的制定提供数据支持.%Dynamic envelope curve is one of the key factors to be considered when defining the dynamic gauge. To accurately obtain the dynamic envelope curve is one big step in design vehicle and also an insurance against dangers in driving. Since the major way to obtain dynamic envelope curve now is by enormous calculation, a measurement system is designed for measuring dynamic envelope curve of high-speed train. Based on binocular vision, the system produces the feature using high power pulse laser, and obtains the dynamic envelope curve of the high-speed train by high-speed acquisition, process and calculation of information that reflects the excursion of train. One field calibration method is proposed to build quickly and efficiently both the position relationship between the two cameras and the transformation between center coordinate system of railway and coordinate system of measurement system. It is proved by experimental results that the measurement precision of the system can reach up to ±0.5 mm, and that the measurement of the dynamic envelope curve of high-speed train is accomplished with high reliability, which can provide useful

  1. 高速列车交会时的风致振动研究%Flow-induced vibration of high-speed trains in passing events

    Institute of Scientific and Technical Information of China (English)

    李雪冰; 侯传伦; 张曙光; 张继业; 张卫华

    2009-01-01

    Considering effects of aerodynamics, vehicle dynamic responses of high-speed trains in passing events were studied here. For obtaining aerodynamic load, a simplified geometry model of a high-speed train (CRH-2) was built, and a 50-degree-of-freedom dynamic system was represented for modeling each of three cars constituting the train, a three-dimensional compressible Reynolds-averaged Navier-Stokes equation, combined with a k-e two-equation turbulence model, was solved by using finite volume method, and the motion of the train was carried out by using sliding meshes. The response of the train considering aerodynamic load or not were calculated by using multi-body simulation. The safety and riding quality of the train in passing events considering aerodynamics or not were discussed. It was found that, the aerodynamic force changes rapidly in the process of passing events, it has obvious effect on the vehicle system dynamics, it causes the train drastic vibration, the most serious deterioration of safety and riding quality can be found at the leading car and the tail one.%为了阐明高速列车交会过程中气动力对列车的系统动力学行为的影响,分别建立了CRH-2动车组的简化几何模型和50个自由度的车辆系统动力学模型.采用有限体积法对三维瞬态可压缩雷诺时均Navier-Stokes方程和k-ε两方程湍流模型进行求解,并通过滑移网格技术实现列车的运动,对考虑和不考虑气动力时的列车系统动力学响应进行了数值模拟,并对两种情况下列车的安全性和舒适性进行了分析讨论.研究发现:气动力在列车交会过程中变化剧烈,对列车系统动力学行为的影响非常明显,交会时列车振动剧烈,头车和尾车的安全性和舒适性明显降低.

  2. Exploration of the Comfort Design of High-speed Train Carriage Lighting%高速列车内室照明舒适性设计研究

    Institute of Scientific and Technical Information of China (English)

    章勇; 徐伯初

    2012-01-01

    从广义的舒适性角度探讨高速列车内室照明设计,分析了照明与视觉特性的关系及影响视觉舒适性的因素,就色温、照度、照射方式和照明的空间布置对心理舒适性的影响进行了详细的论述,并从环境照明、局部照明、装饰照明3个方面总结了高速列车内室照明舒适性设计策略。%It studied high-speed train carriage lighting in the generalized view of comfort and analyzed the relationship between lighting and human visual characteristics,and analyzed the factors which effect visual comfort.Then it was given thorough exploration of psychological comfort which effected by lighting color temperature,illuminance,ways of irradiation,space layout.The strategies of high-speed train carriage lighting comfort design were put forward from environment lighting,local lighting and decoration lighting.

  3. Adaptive Fault-Tolerant Cruise Control for a Class of High-Speed Trains with Unknown Actuator Failure and Control Input Saturation

    Directory of Open Access Journals (Sweden)

    Tao Tao

    2014-01-01

    Full Text Available This paper investigates the position and velocity tracking control of a class of high-speed trains (HST with unknown actuator failures (AF and control input saturation (CIS. Firstly, a nonlinear dynamic model for HST at normal operating status is built. The structure of traction system in HST is analyzed and the corresponding model for HST with unknown AF is presented as well. The type of AF under consideration is that some of the plant inputs are influenced by hopping function. An adaptive model-based fault detection and diagnosis (AMFDD module is proposed based on immersion and invariance (I&I method to make decisions on whether a fault has occurred. A new framework to design a monotone mapping is proposed in I&I method, that is, P(x-monotone. Using on-line obtained fault information, an adaptive law is designed to update the controller parameters to handle unknown AF and CIS in HST simultaneously when some of plant parameters are unknown. Closed-loop stability and asymptotic position and velocity tracking are ensured. Numerical simulations of China Railways High-speed 2 (CRH2 train are provided to verify the effectiveness of the presented scheme.

  4. 强化礼仪训练,培养气质型高铁客服人才%Strengthen Etiquette Training and Train High-speed Rail Temperament Type Customer Service Personnel

    Institute of Scientific and Technical Information of China (English)

    王琳

    2014-01-01

    Currently the rapid development of high-speed rail around the world, the overall quality of high-speed rail society's increasing emphasis on customer service, passenger service on the professional image of a higher requirement, this paper focuses on the methods through strengthening etiquette training by six aspects as morality, professional attitude, career image, communi-cation and communication skills to train temperament type high-speed rail train customer service personnel.%目前世界各地高铁迅速发展,社会对高铁客服人员的综合素质越来越重视,对客运服务人员的职业形象提出了更高的要求,本文主要探讨通过加强礼仪训练,从道德修养、职业心态、职业形象、交际与沟通技巧等六个方面培养气质型高铁客服人才的方法。

  5. 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.

  6. 横风作用下高速列车安全运行速度限值的研究%Research on the Limited Safe Speed of a High-speed Train under Cross Wind

    Institute of Scientific and Technical Information of China (English)

    郗艳红; 毛军; 高亮; 杨国伟; 曲文强

    2012-01-01

    横风作用下的列车安全运行速度限值应通过列车气动特性和车辆轨道动力学特性的分析得到.以我国CRH3型高速列车实车为原型,考虑真实受电弓、转向架等列车的细部特征,假定列车在平地上行驶,对列车速度分别为200、250、300、350和380 km/h,横风速度分别为10、15、20、25和30 m/s,风向角为90°的25个工况进行气动特性的数值模拟,并采用国内实测轨道谱和德国轨道谱分别对这25个工况的车辆轨道动力学性能进行仿真计算和对比分析.结合国家标准和技术规范,给出CRH3型列车在平地上运行时,横风风速与列车最大安全运行速度之间的对应关系,为横风作用下的列车运行安全控制提供参考.%The limited safe speed of a high-speed train under crosswind should be obtained by analyzing the aerodynamic and vehicle-track dynamic characteristics. A real high-speed train of Type CRH3 was taken for case study. The train was assumed to run on a plane area under 25 numerically simulated operating conditions when the train speeds were chosen as 200,250,300,350 and 380 km/h,the crosswind velocities as 10,15,20,25 and 30m/s and the wind direction angle as 90° The detailed characteristics of real bogies and pantographs and so on were taken into account. The dynamic vehicle-track charateristics corresponding to the above 25 operating conditions were calculated respectively and compared in line with the domestic measured track spectra and the German track spectra. In accordance with the National standards and technical specifications concerned, the relationship between the crosswind velocity and the maximum safe operating speed of the CRH3 train running on a plane area was found. The results will play a guiding role in control of safe operation of a train under cross-wind.

  7. 高速列车运行产生的轮轨噪声预测%Prediction of Wheel - rail Noise by Operating High Speed Train

    Institute of Scientific and Technical Information of China (English)

    杨新文; 翟婉明; 和振兴

    2011-01-01

    With the rising of train operation speed, wheel/rail noises are significantly increased. Based on vehicle-track coupled dynamics, random vibration theory and acoustics theory, a model is produced to predict wheel/rail noises by high speed hain operating due to wheel and rail surface roughness, geometric discontinuity in contact, and so on. And the corresponding software WRNOISE (Wheel/Rail Noise)is developed. Compared with existing prediction model TWINS (Track-Wheel Interaction Noise Software), the result shows that the main frequency ranges and trends of the noise of TWINS software simulation values and the present model computation values are consistent. Compared with the model STTIN (Simulation of Train-Track Interaction Noise), the present prediction model can be more fully taken into account the vibration and noise contribution in the axial direction of wheels and the lateral direction of rails. Compared with the noise test values of the high-speed train running on ballasted track and slab track, there are some differences between prediction values of the present model WRNOISE and noise test values, but both trends are in agreement mutually from the viewpoint of wheel-rail noise radiation dominant frequencies.%轮轨噪声随着列车运营速度的提高而显著增大,综合应用车辆-轨道耦合动力学、随机振动理论和声辐射理论,预测由轮轨表面粗糙度、接触不连续几何缺陷等激起的高速列车轮轨噪声,建立轮轨噪声预测模型,并开发相应软件WRNOISE(Wheel/rail Noise).与已有的轮轨噪声预测模型TWINS(Track-Wheel Interaction Noise Software)比较,预测的噪声主频和变化趋势与TWINS的预测结果一致;与STTIN(Simulation ofTrain-TrackInteraction Noise)模型相比,预测模型考虑车轮辐板和钢轨轨腰横向振动噪声的贡献;与有砟和无砟轨道路基区段噪声实测结果的对比表明,WRNOISE模型计算结果与实测结果仍存在一定差异,但

  8. High Speed Compressor Study

    Science.gov (United States)

    2011-12-21

    are listed below, and some of these are discussed at length later. o Heat capacity issues in low temperature regenerators o Pressure drop losses...carried out on a relatively old design of compressor, initially developed for use with a Stirling cycle domestic freezer12, and subsequently used in a...2003), pp 247-253. 3 Wang, X, Dai, W., et al, “Performance of a Stirling -Type Pulse Tube Cooler for High Efficiency Operation at 100Hz

  9. Facilities, Landscape, City. To the origins of a missed meeting. Travelling around the new high-speed Naples-Afragola train station.

    Directory of Open Access Journals (Sweden)

    Luisa Fatigati

    2014-02-01

    Full Text Available This article gives an account of a series of researches and town plans drawn up in the early 21st century about the areas nearby the settlement of the future high-speed train station in Afragola. Ten years later, during the construction of the facilities of the station, designed by the architect Zaha Hadid, it is probably about time to wonder why the hige cost that the construction of the railway required was not redistributed to the community in terms of utilities and improvement in the landscape. And why did no one, neither the public operators not the politic makers, act "rationally", by following up on the technical solutions concerning the problems caused by politics itself? The depressing landscape absolutely recalls the wide gap between design and town planning practices.

  10. High speed preprocessing system

    Indian Academy of Sciences (India)

    M Sankar Kishore

    2000-10-01

    In systems employing tracking, the area of interest is recognized using a high resolution camera and is handed overto the low resolution receiver. The images seen by the low resolution receiver and by the operator through the high resolution camera are different in spatial resolution. In order to establish the correlation between these two images, the high-resolution camera image needsto be preprocessed and made similar to the low-resolution receiver image. This paper discusses the implementation of a suitable preprocessing technique, emphasis being given to develop a system both in hardware and software to reduce processing time. By applying different software/hardware techniques, the execution time has been brought down from a few seconds to a few milliseconds for a typical set of conditions. The hardware is designed around i486 processors and software is developed in PL/M. The system is tested to match the images obtained by two different sensors of the same scene. The hardware and software have been evaluated with different sets of images.

  11. Future trends in coal mining technology at Ikeshima Colliery. Mainly, setup and actual results of high-speed man riding train; Ikeshima Tanko ni okeru tanko gijutsu no doko. Toku ni kosoku jinsha no donyu to jisseki ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Hiromoto, K.; Irie, T.; Murakami, M. [Matsushima Coal Mining Co. Ltd., Fukuoka (Japan); Takahashi, K. [The Coal Mining Research Center, Japan, Tokyo (Japan)

    1997-10-25

    This paper describes the introduction of high-speed man riding train at Ikeshima Coal Mine. The production area is below the sea bottom in the southern offshore of the Ikeshima Island. With increasing the depth of production faces, it is significant for the insurance of operation time to enhance the intensive and highly efficient transportation system and to reduce the transportation and movement time. A high-speed man riding train has been introduced as a transportation system for workers. It is operated in the base gallery at the -650 m level from No. 1 train stop to southern train stop with a distance of 5477 m. It is operated at the maximum speed of 50 km/h, and the single transportation time can be reduced from 18 to 12 minutes. Construction was started in 1995, and practical operation was started in November 1996. Various technical problems were solved concerning the high-speed operation, advanced management of tracks, and monitor and control of operation conditions and a signal system. This system was named as `Goddess-Jikai` which has been operated 19 times a day in the running interval with a return way of 11 km. It has been safely and comfortably operated in a total distance of 33700 km by the end of May 1997. Oscillation is measured by the continuous oscillation monitoring system, and track management is enhanced using a track inspection train. Future high-speed safe operation is expected. 6 figs., 6 tabs.

  12. High speed optical networks

    Science.gov (United States)

    Frankel, Michael Y.; Livas, Jeff

    2005-02-01

    This overview will discuss core network technology and cost trade-offs inherent in choosing between "analog" architectures with high optical transparency, and ones heavily dependent on frequent "digital" signal regeneration. The exact balance will be related to the specific technology choices in each area outlined above, as well as the network needs such as node geographic spread, physical connectivity patterns, and demand loading. Over the course of a decade, optical networks have evolved from simple single-channel SONET regenerator-based links to multi-span multi-channel optically amplified ultra-long haul systems, fueled by high demand for bandwidth at reduced cost. In general, the cost of a well-designed high capacity system is dominated by the number of optical to electrical (OE) and electrical to optical (EO) conversions required. As the reach and channel capacity of the transport systems continued to increase, it became necessary to improve the granularity of the demand connections by introducing (optical add/drop multiplexers) OADMs. Thus, if a node requires only small demand connectivity, most of the optical channels are expressed through without regeneration (OEO). The network costs are correspondingly reduced, partially balanced by the increased cost of the OADM nodes. Lately, the industry has been aggressively pursuing a natural extension of this philosophy towards all-optical "analog" core networks, with each demand touching electrical digital circuitry only at the in/egress nodes. This is expected to produce a substantial elimination of OEO costs, increase in network capacity, and a notionally simpler operation and service turn-up. At the same time, such optical "analog" network requires a large amount of complicated hardware and software for monitoring and manipulating high bit rate optical signals. New and more complex modulation formats that provide resiliency to both optical noise and nonlinear propagation effects are important for extended

  13. Performance evaluation of high speed compressors for high speed multipliers

    Directory of Open Access Journals (Sweden)

    Nirlakalla Ravi

    2011-01-01

    Full Text Available This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP. This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25°C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP and Energy Delay Product (EDP of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.

  14. 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

  15. Effects of different doses of high-speed resistance training on physical performance and quality of life in older women: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Ramirez-Campillo R

    2016-12-01

    Objective: This study aimed to compare the effects of two frequencies of high-speed resistance training (HSRT on physical performance and quality of life of older women.Methods: A total of 24 older women participated in a 12-week HSRT program composed of either two or three sessions/week (equated for volume and intensity. Women were randomized into three arms: a control group (CG, n=8, a resistance training group performing two sessions/week (RT2, n=8, and a resistance training group performing three sessions/week (RT3, n=8. The training program for both experimental groups included exercises that required high-speed concentric muscle actions.Results: No baseline differences were observed among groups. Compared with the CG, both training groups showed similar small to moderate improvements (P<0.05 in muscle strength, power, functional performance, balance, and quality of life.Conclusion: These results suggest that equated for volume and intensity, two and three training sessions/week of HSRT are equally effective for improving physical performance and quality of life of older women. Keywords: aging, muscle strength, adaptation, frailty

  16. 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

  17. 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...

  18. Influence of wheel polygonal wear on interior noise of high-speed trains%高速列车车轮多边形对车内噪声的影响

    Institute of Scientific and Technical Information of China (English)

    Jie ZHANG; Guang-xu HAN; Xin-biao XIAO; Rui-qian WANG; Yue ZHAO; Xue-song JIN

    2014-01-01

    This work presents a detailed investigation conducted into the relationships between wheel polygonal wear and wheel/rail noise, and the interior noise of high-speed trains through extensive experiments and numerical simulations. The field experiments include roundness measurement and characteristics analysis of the high-speed wheels in service, and analysis on the effect of re-profiling on the interior noise of the high-speed coach. The experimental analysis shows that wheel polygonal wear has a great impact on wheel/rail noise and interior noise. In the numerical simulation, the model of high-speed wheel/rail noise caused by the uneven wheel wear is developed by means of the high-speed wheel-track noise software (HWTNS). The calculation model of the interior noise of a high-speed coach is developed based on the hybrid of the finite element method and the statistic energy analysis (FE-SEA). The numerical simulation analyses the effect of the polygonal wear characteristics, such as roughness level, polygon order (or wavelength), and polygon phase, on wheel/rail noise and interior noise of a high-speed coach. The numerical results show that different polygon order with nearly the same roughness levels can cause different wheel/rail noises and interior noises. The polygon with a higher roughness level can cause a larger wheel/rail noise and a larger interior noise. The combination of different polygon phases can make a different wheel circle diameter difference due to wear, but its effect on the interior noise level is not great. This study can provide a basis for improving the criteria for high-speed wheel re-profiling of China’s high-speed trains.

  19. Thinking Improve High-speed Rail Passenger Train Service Training of No Interference%改进高铁客运列车无干扰服务培训的思考

    Institute of Scientific and Technical Information of China (English)

    刘俊英; 郝俊峰

    2014-01-01

    随着铁路的第六次提速,大量安全、便捷、舒适的高铁动车组列车开行。高铁动车组列车以新材料、新技术、新设备、新服务为特色投入铁路客运服务,受到广大旅客的青睐。由于乘务人员服务理念、意识与旅客的需求不匹配,对无干扰服务知识缺乏了解,尤其是列车出现例如超员、晚点等非正常状况,“有干扰无服务”短暂的现象,经传媒的无考量、多层次的放大和延伸,归咎于高铁的“无干扰服务”存在瑕疵,给铁路客服带来了无尽的负面影响。通过探讨无干扰服务和分析其在服务过程中存在的问题,提出了相应的改进方法,进一步提升铁路客服质量,更好地满足人民群众对铁路工作的新期望和新要求。%With the sixth speed railway, a large safe, convenient and comfortable high-speed rail EMU Train. High-speed rail EMU trains with new materials, new technology, new equipment, new service features into the railway passenger services by the majority of visitors of all ages. As the crew service philosophy, consciousness and do not match the needs of passengers, no disruption of service for lack of knowledge, especially in the train appeared such overcrowding, delays and other non-normal conditions,"there is no interference service"transient phenomenon, through the media without consideration multi-level amplification and extension of high-speed rail blamed "no disruption of service,"defective, the customer service to the railway brought endless negative impact. No disruption of service by exploring and analyzing its existence in the service process problem, a corresponding improvement methods to further improve the quality of railway customer service to better meet people's expectations of the new railway work and new requirements.

  20. 高速列车气动阻力地板效应数值研究%Numerical study of ground effects on high speed train aerodynamic drag

    Institute of Scientific and Technical Information of China (English)

    周健; 欧平; 刘沛清; 郭昊

    2016-01-01

    Based on wind tunnel tests of aerodynamic drag on two kinds of 1/25th scale CRH2 models,research of aerodynamic drag with different experimental ground planes was carried out by numerical simulation.The reliability of the numerical methods was verified by comparing the results of simulation and tests.By analyzing the variation of the flow field and resistance distribu-tion on the train body with the usage of the wind tunnel wall,the stationary ground plane,and the moving ground plane in simulation,it is found that:ground effects of different planes have a great influence on the drag measurement of the high speed train;the moving ground plane gives the best simulation performance;the results of drag computed with the other two ground planes are less than that with the moving plane and the difference increases with the increase of the body length,therefore,it is almost impossible to simulate the flow field of the real train operation.Fi-nally the mechanism of influence by ground planes is analyzed and references are provided for drag measurement of high speed train on different ground planes.%针对CRH2型动车组外形,在2种1∶25缩比模型风洞试验基础上,展开基于数值模拟的明线情况高速列车不同地板试验条件阻力测量影响研究。通过与风洞试验结果对比,确定数值方法的可靠性;通过数值模拟风洞壁地板、固定地板、移动地板下高速列车流场分布与阻力变化情况表明,不同试验地板的地面效应对高速列车阻力测量结果影响很大,移动地板模拟效果最佳,固定地板与风洞壁地板阻力测量值小于移动地板情况,且差距随车身长度的增加而增加,很难模拟真实列车运行的流场;通过深入分析不同地板条件的影响机理,为高速列车不同地板条件风洞阻力测量结果提供参考意见。

  1. 高速列车制动盘泵风效应分析%Air-pumping effect analysis for brake disc of high-speed train

    Institute of Scientific and Technical Information of China (English)

    左建勇; 罗卓军

    2014-01-01

    To study the air-pumping characteristics of brake disc during train operation,the finite element models including vehicle,rail,brake disc and related air flow field were put forward. The air-pumping power consumption of brake disc was calculated,and its effect on traction power was analyzed by using dynamic grid and flow-solid conjugation simulation method.Taking a 8-unit high-speed train composed of 4 motor cars and 4 trailers running at 300 km · h-1 as an example,the air-pumping effect of brake disc was simulated and compared.Simulation result indicates that the air-pumping power consumption of brake disc is in proportion to train running speed.The air-pumping power consumption of each car is about 54-70 kW.The air-pumping torque,independent of installation position of brake disc,is mainly influenced by the rotational velocity of brake disc.The proportion of air-pumping power consumption of brake disc reduces with the increase of train running velocity.When train running velocity increases from 200 km·h-1 to 400 km·h-1 ,the proportion of air-pumping power consumption reduces from 12% to 8%. Blocking air from the inlets of brake discs is helpful to reduce the influence of air-pumping power consumption.Taking the train running at 300 km·h-1 as an example,when the inlets of brake discs are blocked,the air-pumping power consumption of brake disc reduces from 489 kW to 68 kW,the basic resistance power consumption consumed by air-pumping power consumption reduces from 9. 0% to 1. 3%,so the method is effective.Obviously,it has greater realistic meanings for the cooling rib structure optimization of brake disc of high-speed train in considering the air-pumping power consumption issue.2 tabs,10 figs,15 refs.%为研究列车运行过程中制动盘泵风特性,建立了列车、轨道、制动盘及其附近空气流场的有限元模型,采用动网格流固耦合仿真方法,计算了制动盘泵风功耗,分析了制动盘泵风对牵引功率的

  2. 基于dSPACE的高速列车牵引传动系统%Drive system based on dSPACE platform for high-speed train

    Institute of Scientific and Technical Information of China (English)

    葛兴来; 宋文胜; 冯晓云

    2012-01-01

    The variable-frequency speed regulation based on rotor flux control for the traction inverter-motor system with three-level diode NPC (Neutral-Point-Clamped) topology is analyzed covering whole speed range of high-speed train. The functional block of rotor-flux-oriented indirect vector control is given and its implementation algorithm is discussed in detail. The compensation algorithm for the precise modeling of the main circuit of three-level traction drive is presented,which considers the effect of dead-time and PWM sampling error. Its simulation model is built based on the hardware-in-the-loop real-time simulation platform of dSPACE and the traction drive control algorithm is programmed based on TMS320F2812 DSP. The comparison of control performance among different main circuit realization methods and among different calculation steps demonstrates the validity of the real-time simulation modeling algorithm and the drive control algorithm.%针对高速列车二极管中点箝位三电平拓扑牵引逆变器-牵引电机系统运行控制的要求,对牵引电机运行全速度范围中基于转子磁通控制的变频调速控制方式进行了分析,给出了转子磁场定向间接矢量控制功能框图并对实现算法进行了详细阐述.考虑死区效应和PWM采样误差的影响提出了三电平牵引传动主电路精确建模的补偿算法,建立了基于dSPACE半实物仿真平台的牵引传动主电路实时仿真模型,根据上述理论分析编制了基于TMS320F2812型DSP的牵引传动控制实现算法.对该控制算法在不同的主电路模型实现算法和不同计算步长下的实时仿真实验结果进行了对比分析,结果验证了该牵引传动主电路实时仿真建模算法和传动控制算法的有效性.

  3. Small Scale High Speed Turbomachinery

    Science.gov (United States)

    London, Adam P. (Inventor); Droppers, Lloyd J. (Inventor); Lehman, Matthew K. (Inventor); Mehra, Amitav (Inventor)

    2015-01-01

    A small scale, high speed turbomachine is described, as well as a process for manufacturing the turbomachine. The turbomachine is manufactured by diffusion bonding stacked sheets of metal foil, each of which has been pre-formed to correspond to a cross section of the turbomachine structure. The turbomachines include rotating elements as well as static structures. Using this process, turbomachines may be manufactured with rotating elements that have outer diameters of less than four inches in size, and/or blading heights of less than 0.1 inches. The rotating elements of the turbomachines are capable of rotating at speeds in excess of 150 feet per second. In addition, cooling features may be added internally to blading to facilitate cooling in high temperature operations.

  4. Numerical study on the restriction speed of train passing curved rail in cross wind

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The results of numerical investigations of aerodynamic forces and moment coefficients of flow passing a simplified train geometry under different wind speeds are summarized. To compute numerically the different coefficients, the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations, combined with the k-ε turbulence model, were solved using finite volume technique. The pres-sure-velocity fields were coupled using the SIMPLE algorithm. At each iteration the pressure correction was obtained by solving a velocity divergence-derived Poisson-like equation. With the computed aerodynamic forces, the formula of the restriction speed at which the train passed curved rail in cross wind was deduced to analyse the influences of aerodynamic forces on the restriction speed. Results of numerical investigations showed that aerodynamic lift and overturn moment increased more and more rapidly with train speed and wind speed. The enhancement trends showed nonlinear phenomena and enhanced risk in the course of train movement. When the train travels at a high speed and encounters a huge cross wind, the influence involved by nonlinear risk increment will extremely impair safety of train. The following conclusion can also be drawn: The effect of aerodynamic lift makes restriction speed reduce, however, the influences of aerodynamic drag to the limit train speed rest on the direction of wind flow. When the wind blows from inner rail to outer rail, aerodynamic forces shall reduce the restriction speed, by contraries, when the wind blows from outer rail to inner rail, aerodynamic forces shall increase the restriction speed.

  5. Numerical study on the restriction speed of train passing curved rail in cross wind

    Institute of Scientific and Technical Information of China (English)

    CHEN RuiLin; ZENG QingYuan; ZHONG XinGu; XIANG Jun; GUO XiaoGang; ZHAO Gang

    2009-01-01

    The results of numerical investigations of aerodynamic forces and moment coefficients of flow passing a simplified train geometry under different wind speeds are summarized. To compute numerically the different coefficients, the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations,combined with the k-ε turbulence model, were solved using finite volume technique. The pressure-velocity fields were coupled using the SIMPLE algorithm. At each iteration the pressure correction was obtained by solving a velocity divergence-derived Poisson-Iike equation. With the computed aerodynamic forces, the formula of the restriction speed at which the train passed curved rail in cross wind was deduced to analyse the influences of aerodynamic forces on the restriction speed. Results of numerical investigations showed that aerodynamic lift and overturn moment increased more and more rapidly with train speed and wind speed. The enhancement trends showed nonlinear phenomena and enhanced risk in the course of train movement. When the train travels at a high speed and encounters a huge cross wind, the influence involved by nonlinear risk increment will extremely impair safety of train.The following conclusion can also he drawn: The effect of aerodynamic lift makes restriction speed reduce, however, the influences of aerodynamic drag to the limit train speed rest on the direction of wind flow. When the wind blows from inner rail to outer rail, aerodynamic forces shall reduce the restriction speed, by contraries, when the wind blows from outer rail to inner rail, aerodynamic forces shall increase the restriction speed.

  6. Exploring of Chinese High-speed Railways

    Institute of Scientific and Technical Information of China (English)

    liuYoumei

    2004-01-01

    Based ion experiences of high-speed railways in foreign countries,the speed-raise situation of the Chinese railways,the research & development and test of high-speed transportation carries,as well as the prospective of high-speed railway in China are introduced.

  7. High-Speed TCP Testing

    Science.gov (United States)

    Brooks, David E.; Gassman, Holly; Beering, Dave R.; Welch, Arun; Hoder, Douglas J.; Ivancic, William D.

    1999-01-01

    Transmission Control Protocol (TCP) is the underlying protocol used within the Internet for reliable information transfer. As such, there is great interest to have all implementations of TCP efficiently interoperate. This is particularly important for links exhibiting long bandwidth-delay products. The tools exist to perform TCP analysis at low rates and low delays. However, for extremely high-rate and lone-delay links such as 622 Mbps over geosynchronous satellites, new tools and testing techniques are required. This paper describes the tools and techniques used to analyze and debug various TCP implementations over high-speed, long-delay links.

  8. Cutting tool materials for high speed machining

    Institute of Scientific and Technical Information of China (English)

    LIU Zhanqiang; AI Xing

    2005-01-01

    High speed machining (HSM) is one of the emerging cutting processes, which is machining at a speed significantlyhigher than the speed commonly in use on the shop floor. In the last twenty years, high speed machining has received great attentions as a technological solution for high productivity in manufacturing. This article reviews the developments of tool materials in high speed machining operations, and the properties, applications and prospective developments of tool materials in HSM are also presented.

  9. 高速磁浮列车对轨道的动力作用及其与轮轨高速铁路的比较%Dynamic Interaction of High Speed Maglev Train on Girders and Its Comparison With the Case in Ordinary High Speed Railwys

    Institute of Scientific and Technical Information of China (English)

    沈志云

    2001-01-01

    Reviewing the achievements in vertical,lateral and longitudinal dynamics of high-speed train,the dynamic interaction between the high-speed ma glev and girders has been studied.A comparison of it with the case in wheel/rail typed high-speed trains was discussed in detail.The main conclus ion obtained is that around 300 km/h wheel/rail trains should be the backbone of the ground high-speed rail transit system.In the case that the extraordinary h igh speed,e.g.400~600 km/h,is required,then the maglev is feasible.The maglev s erves as a kind of complement of the main high-speed rail system.From this poin t of view,the high-speed maglev Pudong Airport Transit Line in Shanghai is imp ortant and should be well constructed.But to construct Beijing-Shanghai wheel/r ail high-speed railway is even more important,and should be put into action as soon as possible.%研究了现有文献关于高速列车动力学方面的论述,就高 速磁浮列车对轨道的动力作用及其与轮轨高速铁路的比较展开讨论。得到的主要结论是:地 面高速轨道交通应以300 km/h左右的轮轨高速铁路为主体;在需要400~600 km/h超高速 的特定条件下,也可以采用磁浮高速列车,作为一种补充。因此,一方面要积极修建上海浦 东机场高速磁浮试验线,一方面要尽早启动京沪轮轨高速铁路的建设。

  10. 口腔颌面部创伤111例患者的伤情分析%High Speed Train Accident Injuries of the Face and Jaws

    Institute of Scientific and Technical Information of China (English)

    王生; 葛若阳; 王靖虓; 蔡志斌; 陈冰; 赵翚; 许志勇

    2013-01-01

    Objective:A collective review and summary of the clinical characteristics of the patients sustained maxillofacial injuries admitted in the front-line hospitals during the "7·23" high speed train accident.Methods:A total of 111 patients with maxillofacial injuries treated in 11 hospitals in Wenzhou City were investigated and reviewed.Data regarding age,gender,causes and effects of injuries,types of fractures,and associated systemic damages and complications.Results:The male to female ratio of the patient was 1.27∶1,and 33.3% of patients were aged between 21 and 30 years.A total of 90 patients (81.1%) showed only soft tissue wounds but vary considerably.13 patients (11.7%)suffered fractures in facial bones and 8 patients (7.2%) had dental trauma.The mandibular fracture were the most frequent.3 patients had total 5 mandibular fractures,accounted for 29.4%.In addition,analysis revealed one-third of the injuries involved at least two body areas,the extremities (31.1%),followed by the chest(25.7%).Conclusions:"7·23"high speed train accident injuries were more prevalent in the maxillofacial region.Soft tissue wounds in various considerations were most common.Mandibular fracture was the most detected in bone damages.The extremities and the chest were the common body area involved in maxillofacial injuries.%目的:总结和探讨“7·23”重特大动车事故发生后一线医院收治的口腔颌面部创伤患者的伤情特点.方法:对温州市11家医院收治的111例动车事故中口腔颌面部创伤患者的病例资料进行统计和分析.结果:111例口腔颌面部创伤患者中男女比例为1.27:1;21~30岁(33.3%)为受伤高峰年龄段.在颌面部创伤中,颌面部软组织伤占81.1%,颌面部骨折占11.7%,牙外伤(牙槽突创伤)患者占7.2%.3例下颌骨骨折患者共发生5处骨折,占骨折的29.4%,发生率最高.合并损伤多发,以四肢损伤和胸部损伤最为多见,分别占31.1%和25.7%.结论:

  11. Flexible high-speed CODEC

    Science.gov (United States)

    Segallis, Greg P.; Wernlund, Jim V.; Corry, Glen

    1993-08-01

    This report is prepared by Harris Government Communication Systems Division for NASA Lewis Research Center under contract NAS3-25087. It is written in accordance with SOW section 4.0 (d) as detailed in section 2.6. The purpose of this document is to provide a summary of the program, performance results and analysis, and a technical assessment. The purpose of this program was to develop a flexible, high-speed CODEC that provides substantial coding gain while maintaining bandwidth efficiency for use in both continuous and bursted data environments for a variety of applications.

  12. Research on Numerical Simulation of Near-field Noise for High-speed TRAIN%高速列车近场气动噪声数值仿真研究

    Institute of Scientific and Technical Information of China (English)

    黄艳艺; 王能

    2015-01-01

    建立了带有空调导流罩,受电弓安装座及转向架安装槽的高速列车组及外部空间在内的气动噪声计算物理模型,结合列车实际运行的边界条件,采用大涡模拟和 FW-H 声学模型,求解高速列车达到一定时速的近场气动噪声。计算结果表明随着速度增加,高速列车声功率显著提高;高速列车表面曲率较大的部位,压力梯度变化大,其声压级也越大;高速列车车顶空调及受电弓导流罩等凸出物,使列车表面的声压增加。%The effect of air and train is increasing with the speed increases of the train, and then the aerodynamic noise is growing quickly. So it is very important to reduce the aerodynamic noise for the noise control of high-speed train. The physical model are three-dimension train dynamic models which consist of three cars (head car, intermediate car and tail car) and the space outside the high-speed train has been built in this paper.  According to the boundary condition of practical working state, base on large eddy simulation(LES) and Fowcs Williams and Hawkings Model, the near-field noise for high-speed train is calculated. The computational results show that with the promotion of the train’s operation speed, sound power of high-speed train increase obviously. While the curvature of the train’s body surface is large, the pressure gradient is big and the sound power level is high. The air-conditioning domes and wind deflector of pantograph make more noise.

  13. Improving Scheme of Train Stops of Shanghai-Nanjing Intercity High-speed Railway Based on Clustering%基于系统聚类的沪宁城际高铁列车停站改进方案

    Institute of Scientific and Technical Information of China (English)

    曲思源

    2015-01-01

    Train stop scheme is an important part of passenger train operation. Based on definition of the intercity high speed railway concept and analysis of Shanghai-Nanjing intercity high speed railway operation condition as well as the existed main problems in the train stop scheme, a system cluster grading method of the stations was put forward according to the passenger flow and the stations of Shanghai-Nanjing intercity high speed railway were divided into 5 grades. By comparing the train stop schemes and according to the concept of public bus, an improvement scheme and some improvement suggestions on the peak periods of different average service interval stop within Shanghai-Nanjing intercity high speed railway stations were presented so as to provide a powerful technical support for train operation organization.%列车停站方案是旅客列车开行方案优化的重要环节。在定义城际高铁概念和分析沪宁城际高铁运营状况以及列车停站方案存在主要问题的基础上,提出根据客流量采用系统聚类法对车站进行分级的方法,并将沪宁城际高铁各站分为5个等级。对比现行列车停站方案,按照公交化的理念,提出了沪宁城际高铁基于高峰和平峰时段车站不同平均服务间隔的停站改进方案和改进建议,为城际高铁运营组织提供有力的技术支撑。

  14. 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

  15. Analysis of external noise spectrum of high-speed railway

    Institute of Scientific and Technical Information of China (English)

    邓永权; 肖新标; 何宾; 金学松

    2014-01-01

    A schematic to make the spectra of the exterior noise of high speed railway was put forward. The exterior noise spectrum was defined based on the characteristics of the high-speed train exterior noise. Its characteristics considered here include identifying the exterior main sources and their locations, their frequency components including the Doppler effect due to the noise sources moving at high speed, the sound field intensity around the train in high-speed operation, the sound radiation path out of the train, and the pressure level and frequency components of the noise at the measuring points specified by the International Organization for Standardization(ISO). The characteristics of the high-speed train exterior noise of the high speed railways in operation were introduced. The advanced measuring systems and their principles for clearly indentifying the exterior noise sources were discussed in detail. Based on the concerned noise results measured at sites, a prediction model was developed to calculate the sound level and the characteristics of the exterior noise at any point where it is difficult to measure and to help to make the exterior noise spectrums. This model was also verified with the test results. The verification shows that there is a good agreement between the theoretical and experimental results.

  16. 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.......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....

  17. Finite Element Analysis on Gear Transmission System of High-Speed Train%高速列车齿轮系统有限元分析

    Institute of Scientific and Technical Information of China (English)

    付永佩; 张卫华; 黄冠华; 梁树林; 王兴宇

    2015-01-01

    To explore the inherent characteristic and the dynamic response of high-speed train gear system, the statics a-nalysis, modal analysis and dynamic analysis of the gear system have been done by establishing three-dimensional entity model and finite element model based on the vibration theory, Hertz contact theory and finite element method. Research on the stress distribution of the gear system under the maximum starting torque is performed, and then the static strength of the system is checked. The possibility of resonance invalidation is researched by identifying modal parameters of the gear system based on modal analysis. There is obvious periodicity in the gear meshing process, the system dynamic re-sponse under rated speed conditions is analyzed and determined by transient dynamics in this process. The results prove that the static strength is in the range of security and the gear system will not produce resonance. On the premise of con-stant input, the internal excitation such as stiffness excitation, error excitation, etc. produced due to gear mesh makes the system output have a cyclical fluctuation and has an impact on the system stability.%为探究高速列车齿轮系统的固有特性和动力响应情况,通过建立齿轮系统三维实体模型和有限元模型,基于振动理论、Hertz接触理论以及有限单元法,对系统进行静力学分析、模态分析和动力学分析。研究在最大启动扭矩作用下齿轮系统应力分布情况,对齿轮系统静强度进行校核;通过模态分析识别齿轮系统模态参数,研究系统共振失效可能性;齿轮啮合过程具有明显周期性,通过瞬态动力学分析确定齿轮啮合周期内,系统在额定转速工况下的动力学响应情况。结果表明:静力学分析表明齿轮系统静强度在安全范围内,模态分析表明系统不会产生共振,瞬态分析表明在输入恒定的前提下,由于齿轮啮合产生了刚度激励、误差

  18. 基于航空噪声指标的高速列车观光区噪声评价%Noise Evaluation in the Tourist Cabin of High-speed Train by Using Aircraft Noise Criterion

    Institute of Scientific and Technical Information of China (English)

    张捷; 肖新标; 张玉梅; 王瑞乾; 王谛; 金学松

    2013-01-01

    Based on field measurements,the noise characteristics in the tourist cabin of a high-speed train are analyzed at a high running speed between 300 to 400 km/h.So far,there is still no a unified criterion in the word to evaluate the noise level in the carriage of high-speed train reasonably,while A-weighted sound level has a shortcoming in the noise evaluation.In order to further clear the shortcoming,A-weighted sound level is discussed through the detailed contrast to white noise combined with increasing sound level in different frequency bands.An aircraft noise evaluation index is used to evaluate the interior noise of the high-speed train.The obtained results indicate that:the noise in the tourist cabin of the high-speed train is dominated by the components of low and middle frequencies.Such a noise would be underestimated when A-weighted sound level is used.There is high similarity of frequency characteristics between interior noise of high-speed train and it of aircraft.The aircraft noise evaluation index is more suitable for the characteristic evaluation of interior noise of high-speed train.This paper could provide evidence for framing new proper noise evaluation criterion for high-speed train.%基于现场测试结果,对300~400 km/h速度下高速列车观光区噪声进行分析,明确车内噪声动态特性.由于国内外还没有统一的高速列车车内噪声评价标准,传统的A计权声压级又在噪声评价中存在不足之处.为研究A计权声压级是否适合高速列车车内噪声评价,通过白噪声对比、分频段声压级比例增加等方法,讨论使用A计权声压级评价车内噪声时的不足之处.运用航空噪声评价指标对高速列车车内噪声进行评价研究.研究结果表明,300 km/h以上高速列车车内噪声具有显著的中低频特性,使用A计权声压级评价会低估车内噪声水平.高速列车观光区噪声频谱特性和飞机舱内噪声频谱特性具有很高的相似性,选择

  19. 高速铁路隧道列车风作用下接触网安全性分析%Analysis of catenary's safety under train wind action in high-speed railway tunnel

    Institute of Scientific and Technical Information of China (English)

    施成华; 杨伟超; 彭立敏; 王照伟; 雷明锋

    2012-01-01

    采用数值模拟方法,对高速列车在隧道内运行过程中所产生的列车风速度的变化过程进行分析,计算隧道内不同位置在列车运行过程中的最大风速和最大风压,进一步研究隧道内预留滑道槽型和螺栓锚固型接触网在列车反复冲击压力作用下的安全性.研究结果表明:隧道内不同断面的接触网设施只在列车车身运行至该断面的一段时间内才承受负向列车风(与列车运行方向相反);离列车表面越近的位置,列车风的速度越大;对于螺栓锚固型接触网悬挂件,在单线隧道350 km/h行车条件下,隧道衬砌混凝土中的最大拉应力已接近混凝土的疲劳抗拉强度,应采取适当的加强措施;对于滑道槽式接触网悬挂件,在列车风的反复作用下是安全的.%By using the numerical simulation method, the change process of wind speed when high-speed train running in tunnel was studied, the maximum wind speed and wind pressure at different positions in tunnel were calculated, and then the safety of slide-type and anchor-type catenary in tunnel under the repeated impact pressure caused by train running was studied. The calculated results show that at different cross-sections in tunnel, the negative train wind (opposite to train running direction) only occurs in a certain period when the whole train is through this section. The nearer the position is to the train surface, the greater the speed of the train wind. For the anchor-type catenary, the greatest tensile stress in the tunnel lining is close to the fatigue tensile strength of concrete at 350 km/h driving speed in single-track tunnel, and appropriate measures should be taken to strengthen it. For the slide-type catenary, it is safe under repeated action caused by train wind.

  20. Measures Study and Effect Analysis of Noise Reduction for High Speed Inspection Train%高速综合检测列车降噪措施研究与效果分析

    Institute of Scientific and Technical Information of China (English)

    张丽荣; 张志军; 王东川

    2011-01-01

    This paper shows the example of noise control measures for 400 km/h high speed inspection train and presents the measures study and effect analysis of noise reduction for high speed inspection train. Based on analyzing the source noise of high speed inspection train, aiming at reduce the source noise and noise path controlling technique, we used such noising reduction method as high damping on car body, sound insulation and absorbing material in equipment cabin, damping treatment in air condition tube and noise absorbing material in brake unit to reduce the sound pressure level in the train. The static and dynamic test results of the train shows that the noise reduction measures have reached the noise reduction target well. The sound pressure has been controlled bellow 68dB successfully.%以400 km/h高速综合检测列车噪声控制措施为例,在分析高速检测车的噪声来源的基础上,针对噪声产生的根源和有关噪声控制技术,分别采取车体高阻尼减震、设备舱隔音吸音、空调管路阻尼处理、制动单元吸音处理等降噪措施来降低车内噪声.从高速综合检测列车在静止状态和运行状态下的测试结果分析,针对车内采取的降噪措施,达到了预期的隔音降噪效果,整车声压值水平控制在68 dB以内.

  1. Speed endurance training is a powerful stimulus for physiological adaptations and performance improvements of athletes.

    Science.gov (United States)

    Iaia, F M; Bangsbo, J

    2010-10-01

    The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain the oxidative capacity and improve intense short-duration/repeated high-intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high-intensity sessions, speed endurance training is also useful in enhancing performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle substrate levels, glycolytic and oxidative enzymes activity, and membrane transport proteins involved in pH regulation. Instead they appear to be related to a reduced energy expenditure during submaximal exercise and a higher expression of muscle Na(+) ,K(+) pump α-subunits, which via a higher Na(+) ,K(+) pump activity during exercise may delay fatigue development during intense exercise. In conclusion, athletes from disciplines involving periods of intense exercise can benefit from the inclusion of speed endurance sessions in their training programs.

  2. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Science.gov (United States)

    2010-07-01

    ...) All cars for high-speed rail systems, including but not limited to those using “maglev” or high speed...., not used by freight trains) or guideway, in which stations are constructed in accordance with...

  3. Research on Exterior Aerodynamic Noise Prediction of High-speed Trains Based on Neural Network%基于神经网络方法的高速列车车外气动噪声预测

    Institute of Scientific and Technical Information of China (English)

    李辉; 肖新标; 金学松

    2015-01-01

    The neural network method was used to predict exterior aerodynamic noise of high-speed trains. Based on Lighthill’s acoustic analogy theory, an aerodynamic noise computation model of the high-speed train was built. Then, a neural network model for aerodynamic noise prediction was built up using Levenberg-Marquardt (LM) algorithm. The prediction model was trained by the sample data of the external aerodynamic noise signal, and the trained neural network model was used to predict the external aerodynamic noise. The results show that the neural network method for aerodynamic noise prediction is a quite accurate algorithm and can be used for exterior aerodynamic noise prediction of high-speed trains.%利用神经网络进行高速列车车外气动噪声预测研究。基于Lighthill声学类比理论,建立高速列车气动噪声计算模型。在此基础上采用Levenberg-Marquardt (LM)算法建立车外气动噪声的神经网络预测模型,选取车外气动噪声样本点对预测模型进行训练,用训练好的神经网络预测模型预测车外气动噪声。结果表明,建立的神经网络模型对车外噪声具有较好的预测效果,可以用来进行高速列车车外噪声预测。

  4. Explosive strength training improves speed and agility in wheelchair basketball athletes

    Directory of Open Access Journals (Sweden)

    Tarik Ozmen

    2014-04-01

    Full Text Available INTRODUCTION: Wheelchair basketball is a paralympic sport characterized by intermittent high-intensity activities that require explosive strength and speed. OBJECTIVE: To investigate the effect of explosive strength training on speed and agility performance in wheelchair basketball players. METHODS: Ten male wheelchair basketball players (Mage=31±4 yrs were divided into two groups [i.e. explosive strength training (ES; control (CN] based on International Wheelchair Basketball Federation (IWBF classification scores. The ES group underwent 6-weeks of training, twice weekly, at 50% 1RM, 10-12 repetitions and 3-4 sets in addition to routine training. Effects of training were measured by the 20 m sprint test and Illinois agility test. RESULTS: The ES group, showed significantly higher increases in speed and agility performance (p ≤ .05. CONCLUSION: A short-duration (i.e. 6-week explosive strength training programme in wheelchair basketball athletes results in significant improvements in sprint and agility performance.

  5. Experimental high-speed network

    Science.gov (United States)

    McNeill, Kevin M.; Klein, William P.; Vercillo, Richard; Alsafadi, Yasser H.; Parra, Miguel V.; Dallas, William J.

    1993-09-01

    Many existing local area networking protocols currently applied in medical imaging were originally designed for relatively low-speed, low-volume networking. These protocols utilize small packet sizes appropriate for text based communication. Local area networks of this type typically provide raw bandwidth under 125 MHz. These older network technologies are not optimized for the low delay, high data traffic environment of a totally digital radiology department. Some current implementations use point-to-point links when greater bandwidth is required. However, the use of point-to-point communications for a total digital radiology department network presents many disadvantages. This paper describes work on an experimental multi-access local area network called XFT. The work includes the protocol specification, and the design and implementation of network interface hardware and software. The protocol specifies the Physical and Data Link layers (OSI layers 1 & 2) for a fiber-optic based token ring providing a raw bandwidth of 500 MHz. The protocol design and implementation of the XFT interface hardware includes many features to optimize image transfer and provide flexibility for additional future enhancements which include: a modular hardware design supporting easy portability to a variety of host system buses, a versatile message buffer design providing 16 MB of memory, and the capability to extend the raw bandwidth of the network to 3.0 GHz.

  6. Simulation Study on Serodynamic Noise of the High Speed Trains Based on CAA%基于CAA的高速动车组气动噪声仿真研究

    Institute of Scientific and Technical Information of China (English)

    王成强; 邢海英; 郑继峰

    2015-01-01

    随着列车运行速度的提高,气动噪声在总噪声中所占的比重越来越大,降低气动噪声已成为影响高速铁路可持续发展的关键问题。在理论研究基础上,采用了混合法来研究高速动车组受电弓周围的气动噪声特性。首先,对高速列车在RANS(雷诺平均模拟)方法计算下的统计结果进行分析,研究高速列车受电弓区域的流场特征。然后,应用非线性声学求解方法(NLAS)研究近场噪声,分析了不同部位对气动噪声的贡献。最后,采用FW-H声学比拟方法来分析远场气动噪声,通过不同测试点研究了远场噪声分布特性。%With train speeding up, the aeroacoustics of the high-speed train is becoming more and more important. Reducing aerodynamic noise has become one of the most significant factors to control the noise of the high-speed train. This paper adopted the hybrid method to study the aerodynamic noise around the high-speed train panto⁃graph. The feature of the pantograph's flow field dominates the generation of aerodynamic noise, therefore the flow field obtained by the RANS solution is firstly analyzed. Then the nonlinear acoustics solver (NLAS) approach is ad⁃opted to study the aerodynamic noise in the near field of the CRH3 high speed train. Finally, far field aerodynamic noise study is carried out by solving the Ffowcs-Williams/Hawking (FW-H) equation. By use of probes, the contri⁃bution of different parts of the pantograph for aerodynamic noise is discussed.

  7. The effect of speed of processing training on microsaccade amplitude.

    Directory of Open Access Journals (Sweden)

    Stephen Layfield

    Full Text Available Older adults experience cognitive deficits that can lead to driving errors and a loss of mobility. Fortunately, some of these deficits can be ameliorated with targeted interventions which improve the speed and accuracy of simultaneous attention to a central and a peripheral stimulus called Speed of Processing training. To date, the mechanisms behind this effective training are unknown. We hypothesized that one potential mechanism underlying this training is a change in distribution of eye movements of different amplitudes. Microsaccades are small amplitude eye movements made when fixating on a stimulus, and are thought to counteract the "visual fading" that occurs when static stimuli are presented. Due to retinal anatomy, larger microsaccadic eye movements are needed to move a peripheral stimulus between receptive fields and counteract visual fading. Alternatively, larger microsaccades may decrease performance due to neural suppression. Because larger microsaccades could aid or hinder peripheral vision, we examine the distribution of microsaccades during stimulus presentation. Our results indicate that there is no statistically significant change in the proportion of large amplitude microsaccades during a Useful Field of View-like task after training in a small sample of older adults. Speed of Processing training does not appear to result in changes in microsaccade amplitude, suggesting that the mechanism underlying Speed of Processing training is unlikely to rely on microsaccades.

  8. 基于编织算法的复线高速磁浮列车运行图铺画方法%Method for drawing double-track high-speed maglev train diagram based on knitting algorithm

    Institute of Scientific and Technical Information of China (English)

    张其亮; 陈永生; 杜磊

    2011-01-01

    根据高速磁浮线路结构和运行控制系统的特点,建立了复线高速磁浮列车运行图编制模型,设计了编织算法对模型进行求解.该算法严格按照列车在各车站的发车时间顺序,对上、下行列车运行线如同“织毛衣”般交叉铺画,在遇到列车冲突时通过更改列车路由和增加发车间隔等方法予以及时化解,逐步得到整体优化的列车运行图.算例分析表明,该方法优化速度快,能够有效地进行高速磁浮列车运行图的铺画.%Based on the characteristics of high-speed maglev train line structure and operation control system, this paper set up a model for the high-speed maglev train diagram of double-track lines, and put forward the knitting algorithm to resolve the model. The algorithm drew the up and down maglev train running lines in chronological order of trains' departure time from stations, which tended to do some knitting. When meeting the conflict, the algorithm resolved it by changing the station tracks or increasing the departure time intervals, at last it gained global optimization maglev train diagram step by step. A numerical example shows that the method can draw the maglev train diagram quickly and effectively.

  9. 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.

  10. Comparison of High Speed Congestion Control Protocols

    Directory of Open Access Journals (Sweden)

    Jawhar Ben Abed

    2012-10-01

    Full Text Available Congestion control limits the quantity of information input at a rate less important than that of thetransmission one to ensure good performance as well as protect against overload and blocking of thenetwork. Researchers have done a great deal of work on improving congestion control protocols,especially on high speed networks.In this paper, we will be studying the congestion control alongside low and high speed congestion controlprotocols. We will be also simulating, evaluating, and comparing eight of high speed congestion controlprotocols : Bic TCP, Cubic TCP, Hamilton TCP, HighSpeed TCP, Illinois TCP, Scalable TCP,Compound TCP and YeAH TCP, with multiple flows.

  11. 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...

  12. 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...

  13. Effect of speed endurance and strength training on performance, running economy and muscular adaptations in endurance-trained runners

    DEFF Research Database (Denmark)

    Vorup Petersen, Jacob; Tybirk Nielsen, Jonas; Gunnarsson, Thomas Petursson;

    2016-01-01

    period. Maximal aerobic speed was 0.6 km h(-1) higher (P ...PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were...... randomly assigned to either a combined strength and SE training (CSS; n = 9) or a control (CON; n = 7) group. For 8 weeks, CSS replaced their normal moderate-intensity training (~63 km week(-1)) with SE (2 × week(-1)) and strength training (2 × week(-1)) as well as aerobic high (1 × week(-1)) and moderate...

  14. High-Speed Ring Bus

    Science.gov (United States)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There

  15. 基于THERP-Markov原理的高铁列调人因可靠性分析%Human Reliability Analysis on High-speed Train Dispatcher Based on THERP and Markov Theories

    Institute of Scientific and Technical Information of China (English)

    徐培娟; 彭其渊; 文超; 郭经纬; 占曙光

    2014-01-01

    In the dispatching system of high-speed railway, the dispatching terminal equipment is used by dispatchers who manage the running high-speed trains and related production activities, so reliability of dispatchers is directly related to the safety of high-speed trains. In this paper, THERP theory is introduced from nuclear plant industry to calculate the failure rate and the corresponding confidence intervals of dispatchers under static conditions, combining with the characteristics of their job content. According to the Markov chain theory, then the probability state transferring equations is established to study law of the dispatcher reliability under a certain influencing factor, by Laplace transform. Finally, the task about setting train speed limitation done by the dispatcher is taken for an example to analyze the static and dynamic reliability, when the person is under the influence of different level of pressure. The results show that human error rate about setting train speed limitation is lowest with 0.010 4 under medium pressure state.%在高速铁路调度指挥系统中,列调人员通过调度终端来指挥铁路现场的生产活动,调度员的操作直接影响列车的运行.本文引入核电工业中的THERP理论,结合列调操作特征来计算静态条件下列调操作失误率及其置信区间;并结合马尔科夫链原理,建立状态转移率方程,通过拉普拉斯变换得出单影响因子作用下列调可靠性的状态概率变化规律.最后,以执行列控限速任务为例,得出列调的静态失误率及压力影响因子作用下人因动态可靠性变化规律.研究结果表明:在压力适中的情况下,列控限速执行失败率最低,为0.0104.

  16. Noise Test and Analysis of 350 km/h High-speed Train with Different Distances%350km/h高速列车噪声随距离变化的衰减特性

    Institute of Scientific and Technical Information of China (English)

    董海山; 贺玉龙; 杨立中; 邓俊

    2012-01-01

    In order to investigate the noise level of different line forms of 350 km/h high-speed train, the noise intensity at different distance from the Beijing-Tianjin Inter-City high-speed railway was tested and analyzed. The result indicates that the noise level radiated by the train reaches the highest at 60m distance. Then the noise level decreases with the distance increasing. The result is significant for noise reduction design of the express train-sets.%为了研究350 km/h高速列车运行状态下噪声随距离衰减规律,对已开通运行的京津城际铁路列车运行时辐射噪声进行测试与分析,得出京津城际铁路噪声随距离衰减规律.结果表明,在高架桥路段(桥墩高6m),距离60m处噪声达到最大,在60m以后,噪声开始衰减明显.其研究结果对今后高速铁路降噪设计具有一定的参考价值.

  17. Reducing Heating In High-Speed Cinematography

    Science.gov (United States)

    Slater, Howard A.

    1989-01-01

    Infrared-absorbing and infrared-reflecting glass filters simple and effective means for reducing rise in temperature during high-speed motion-picture photography. "Hot-mirror" and "cold-mirror" configurations, employed in projection of images, helps prevent excessive heating of scenes by powerful lamps used in high-speed photography.

  18. 基于光纤陀螺的高速列车轨迹无线测试仪%Wireless Test Instruments of Track of High Speed Train Based on Fiber Optic-gyro

    Institute of Scientific and Technical Information of China (English)

    王锋; 张兵; 张占军; 谭佳丰

    2012-01-01

    For high—speed trains are totally enclosed trains, this paper gives an introduction for the wireless test instrument designed for the highspeed train track testing, based on the fiber optic gyroscope, the three—dimensional acceleration sensor and the low—power wireless communication module Zigbee's JN5139. The paper gives detailed description and illustration on the works and the features of the fiberoptic gyroscope and focuses on the hardware design and the software logical control of each functional module, such as the wireless communication module, the clock circuit, the high—capacity data storage systems and so on. The experiments show that the detection system can a-chieve the performance of high—speed train track detection, especially for closed highspeed train track test, the communication distance up to 1000 m , the battery lasts 72 hours , the data storage space of up to one month , which is very effective wireless test system.%针对高速列车是全封闭式的动车,介绍了基于光纤陀螺及三向加速度和Zigbee低功耗无线通信模块JN5139为基础,用于高速列车轨迹测试的无线测试仪设计,详细阐述了光纤陀螺的工作原理及特点、无线通信模块、时钟电路、大容量数据存储系统等功能模块的硬件设计以及相互之间软件逻辑控制.试验表明该测试仪能实现高速列车轨迹检测功能,特别适合于封闭的高速列车的试验,其通讯距离可以达1000米,电池可持续工作72小时,数据存储空间可达1个月,是非常有效的无线测试系统.

  19. Self-management: patient section. Training for speed.

    Science.gov (United States)

    Liebenson, Craig

    2009-10-01

    Speed is typically considered an inherited trait. While runners are born not made, everyone can improve their speed. There are some basic tips and training exercises that can improve any athlete or "weekend warrior's" speed. To optimize a person's running ability a specific stimulus is needed. This entails re-programming the muscle firing patterns by creating a new movement engram on a subcortical basis. In the young athlete, the nervous system is most plastic, so if good habits are programmed early enough in the developmental training of a young athlete, they will provide a solid foundation for the future (Balyi et al., 2005; Bompa, 1995; Bouchard et al., 1997; Higgs et al., 2008).

  20. 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.

  1. Design of high speed camera based on CMOS technology

    Science.gov (United States)

    Park, Sei-Hun; An, Jun-Sick; Oh, Tae-Seok; Kim, Il-Hwan

    2007-12-01

    The capacity of a high speed camera in taking high speed images has been evaluated using CMOS image sensors. There are 2 types of image sensors, namely, CCD and CMOS sensors. CMOS sensor consumes less power than CCD sensor and can take images more rapidly. High speed camera with built-in CMOS sensor is widely used in vehicle crash tests and airbag controls, golf training aids, and in bullet direction measurement in the military. The High Speed Camera System made in this study has the following components: CMOS image sensor that can take about 500 frames per second at a resolution of 1280*1024; FPGA and DDR2 memory that control the image sensor and save images; Camera Link Module that transmits saved data to PC; and RS-422 communication function that enables control of the camera from a PC.

  2. 高速列车气动噪声Lighthill声类比的有限元分析%Finite Elements Analysis of High - speed Train Wind Noise in Lighthill' s Acoustic Analogy

    Institute of Scientific and Technical Information of China (English)

    杨晓宇; 高阳; 程亚军; 刘凤华

    2011-01-01

    With the constant increase of the trains' speed, the aerodynamic noise gradually succeeds the traditional track noise and becomes the main noise source of the high-speed trains. In this paper, a hybrid CFD/CAA wind noise model for the high speed trains based on Lighthill' s analogy is constructed utilizing a professional finite elements acoustic simulator ACTRAN-Aeroacoustics. Numerical results of fluid and acoustic fields are reported and discussed. Some important issues for further development of the simulation model are discussed. The simulation results show that there are three dominant locations for the aerodynamic noise sources which depend on the shape of the train. With the use of this model, the influence of the train's shape on the wind noise can be analyzed, and the optimization for low noise design of the train can be realized.%随列车行驶速度逐年提高,气动噪声源逐渐超越轮轨噪声成为高速列车最主要噪声源.通过ACTRAN -Aeroacoustics建立基于Lighthill声类比理论的高速列车气动噪声CFD/CAA混合数值分析模型.计算并讨论非定常流场与气动声场计算结果,并分析此数值模型可以进一步完善的一些重要方面.目前数值模拟结果表明列车高速行驶状态气动噪声源主要集中在与车身气动外形密切相关的三类位置上,且通过当前模型可以有效剖析列车车身气动外形设计对气动噪声的影响以及相应的高速列车低噪音优化途径.

  3. [Effects of occupational stress and related factors to the mood of speed train drivers].

    Science.gov (United States)

    Zhou, Wenhui; Gu, Guizhen; Wu, Hui; Yu, Shanfa

    2014-04-01

    To explore the effect of occupational stress and related factors to the mood of speed train drivers. By using cluster sampling method, a cross-sectional study was conducted in 1 352 speed train drivers (including 291 passenger train drivers, 640 freight trains drivers, 342 passenger shunting train drivers, and 79 High Speed Rail drivers) from a Railway Bureau depot. The survey included mood, individual factors, occupational stress factors, personality factors and mitigating factors. The mood status was evaluated by mood scale, and the occupational stress factors, personality factors and mitigating factors were measured by the revised effort-reward imbalance (ERI) model questionnaires and occupational stress measurement scale. Correlation analysis showed that the mood score was negative correlated with age(r = -0.07, P = 0.01), working age (r = -0.07, P = 0.01), ERI(r = -0.53, P extrinsic effort(r = -0.41, P intrinsic effort(r = -0.39, P rewards(r = 0.42, P rewards, intrinsic effort, self-esteem, extrinsic effort and coping strategy were the predictors, which could explain the 74.36% of total variance. Most occupational stress factors may cause negative mood, but rewards, self-esteem, social support and coping strategy were the protection factors of mood; different train drivers had different mood status, High Speed Rail drivers were the worst, and passenger train drivers were the best.

  4. Active control system for high speed windmills

    Science.gov (United States)

    Avery, D.E.

    1988-01-12

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

  5. 高速列车流固耦合振动的研究方法及其应用%Research Method and Application of Fluid-solid Coupling Vibration for High-speed Train

    Institute of Scientific and Technical Information of China (English)

    崔涛; 张卫华; 孙帮成

    2013-01-01

    结合既有系统动力学分析方法和空气动力学研究方法,给出基于任意拉格朗日-欧拉法的高速列车与气流耦合振动的数值分析方法,包括离线耦合分析方法和在线耦合分析方法,在线耦合又可分为显式耦合分析方法和隐式耦合分析方法.介绍不同耦合分析方法在站台通过、高速交会、侧风等运行安全性方面的应用,考虑流固关系后,列车侧风安全性和交会安全性进一步降低.流固耦合数值分析方法在实例应用中得到直接或间接的验证,为高速列车流固关系研究提供1种方法和思路.%The new numeric analysis methodology based on Arbitrary Lagrangian-Eulerian(ALE) for high-speed train and airflow coupling vibration was presented by integrating the existing Finite Volume Method of Computational Fluid Dynamics and the numerical simulation method of Multi-Body Systems Dynamics.This methodology included off-line coupling and on-line coupling,and the latter included the explicit coupling method and implicit coupling method.The applications of these coupling methods in platform passing,high-speed crossing and side winds were introduced.Safety of train crossing and trains running in side winds was reduced when the coupling relationship of train system and airflow was taken into account.The methodology was verified in applications directly and indirectly.It offers a methodology and a idea for study of fluid-solid coupling relationship of high-speed trains.

  6. Characteristics of Train Wind and Analyses of Personnel Security in High-Speed Railway Double-Line Tunnel%高速铁路双线隧道列车风特性与人员安全性分析

    Institute of Scientific and Technical Information of China (English)

    费瑞振; 彭立敏; 施成华; 杨伟超; 雷明锋

    2013-01-01

    According to the three-dimensional incompressible Navier-Stokes equations and the standard turbulence model,the 100 double-line tunnel cross-section which is generally used in high-speed railway of China is studied,this paper has made a thorough study on the variation rules and distribution characteristics of train wind,and has calculated the maximum wind speed at different positions on the two evacuation passageways,at the same time the influence that train wind on personnel safety is further discussed.The results show that:Train wind is complex three-dimensional flow which is changed with time and space,person should avoid activities at dangerous time,personnel safety may be threatened by train wind on two train driving conditions:one is that a single train runs through tunnel normally while the other is that another train runs beside a train parked in the tunnel.Corresponding measures should be taken to avoid accidents.%根据三维不可压缩Navier-Stokes方程和标准k-ε湍流模型,以我国高速铁路普遍采用的100m2双线隧道为研究对象,对高速列车在隧道内运行时列车风的变化规律和分布特征进行了深入研究,计算隧道内两侧疏散通道上不同位置在列车运行过程中的最大风速,进一步分析在列车风作用下人员的安全性.研究表明:列车风是随时间和空间而变的复杂三维流动,人员应避免在危险时段活动,单车正常运行和存在列车事故时列车风均有可能对人员造成安全威胁,需采取相关措施避免事故发生.

  7. ERROR CORRECTION IN HIGH SPEED ARITHMETIC,

    Science.gov (United States)

    The errors due to a faulty high speed multiplier are shown to be iterative in nature. These errors are analyzed in various aspects. The arithmetic coding technique is suggested for the improvement of high speed multiplier reliability. Through a number theoretic investigation, a large class of arithmetic codes for single iterative error correction are developed. The codes are shown to have near-optimal rates and to render a simple decoding method. The implementation of these codes seems highly practical. (Author)

  8. High-intensity training in football.

    Science.gov (United States)

    Iaia, F Marcello; Rampinini, Ermanno; Bangsbo, Jens

    2009-09-01

    This article reviews the major physiological and performance effects of aerobic high-intensity and speed-endurance training in football, and provides insight on implementation of individual game-related physical training. Analysis and physiological measurements have revealed that modern football is highly energetically demanding, and the ability to perform repeated high-intensity work is of importance for the players. Furthermore, the most successful teams perform more high-intensity activities during a game when in possession of the ball. Hence, footballers need a high fitness level to cope with the physical demands of the game. Studies on football players have shown that 8 to 12 wk of aerobic high-intensity running training (> 85% HR(max)) leads to VO2(max) enhancement (5% to 11%), increased running economy (3% to 7%), and lower blood lactate accumulation during submaximal exercise, as well as improvements in the yo-yo intermittent recovery (YYIR) test performance (13%). Similar adaptations are observed when performing aerobic high-intensity training with small-sided games. Speed-endurance training has a positive effect on football-specific endurance, as shown by the marked improvements in the YYIR test (22% to 28%) and the ability to perform repeated sprints (approximately 2%). In conclusion, both aerobic and speed-endurance training can be used during the season to improve high-intensity intermittent exercise performance. The type and amount of training should be game related and specific to the technical, tactical, and physical demands imposed on each player.

  9. 高速列车节能运行优化控制方法研究%Research on Optimization Control Method of Energy-saving Operation of High-speed Trains

    Institute of Scientific and Technical Information of China (English)

    刘建强; 魏远乐; 胡辉

    2014-01-01

    Energy-saving operation of high-speed trains is of utmost importance to saving energy and reducing consumption .In this paper ,applying the modern optimal control theory and considering feedback of regenera-tive braking energy ,the minimum energy consumption calculation model of high-speed trains was established under constraint of fixed running time .The optimal control principle was worked cut with the minimum formu-la ,which was the combination of four kinds of operation modes ,i .e .,the maximum traction ,uniform speed , idle running and maximum braking .Then according to the actual train characteristic curve and measured resist-ance curve ,a new energy-saving operation control method was proposed .With this method ,the maximum train running speed corresponding to the lowest energy consumption was found .Thus every working point of the maximum traction ,uniform speed ,idle running and maximum braking versus the minimum energy con-sumption for the whole journey was calculated .In order to verify the effectiveness of the proposed method ,the energy-saving operation control method was applied to CRH3 (EMUs) running between Beijing and Tianjin . The results show that the energy consumption decreases about 14% compared with the actual test results .The study provides a basis for energy-saving operation control of high-speed trains .%高速列车节能运行控制对高速列车节能降耗至关重要。基于现代最优控制理论,考虑列车再生制动能量反馈,建立高速列车在定时约束条件下最小能耗计算模型,利用极小值公式推导得到最佳控制原则为最大牵引、匀速、惰行及最大制动这4种运行方式组合。在此基础上,依据高速列车牵引特性和阻力特性曲线,提出一种列车节能运行控制方法,基于此方法求解得到列车运行能量消耗最低所对应的最大速度值,从而计算得出整个运行过程中列车运行能量消耗最小时最大牵引、匀速、惰

  10. Damping Bearings In High-Speed Turbomachines

    Science.gov (United States)

    Von Pragenau, George L.

    1994-01-01

    Paper presents comparison of damping bearings with traditional ball, roller, and hydrostatic bearings in high-speed cryogenic turbopumps. Concept of damping bearings described in "Damping Seals and Bearings for a Turbomachine" (MFS-28345).

  11. On China's High-Speed Railway Technology

    Institute of Scientific and Technical Information of China (English)

    You-tong FANG

    2011-01-01

    Energy and environmental issues have become increasingly prominent in matters of transportation.Compared with road,air,and sea transportation,railway transportation has the advantages of a large transmission capacity,with rapid,safe,and on-time travel,requiring less land resources,with lower energy consumption,less environmental pollution,and the capacity to operate under most weather conditions.In particular,high-speed railway technology has been growing rapidly.Since the world's first high-speed railway was built in Japan in 1964,more than ten countries and regions have developed high-speed railways,operating over a total of more than 10000 km.High-speed railways not only provide the public with a new type of rapid,convenient,safe,and comfortable travel,but also greatly boost the socio-economic development of the country.

  12. Speed, Strength and Endurance Training for Adolescent Footballers in Kenya

    OpenAIRE

    Igendia, Mikael

    2012-01-01

    The subject of this thesis was speed, strength and endurance training for adolescent footballers in Kenya. The commissioner of this work was the Football Kenya Federation (FKF). Football is a popular sport in Kenya, but the development of football in Kenya has been ineffective due to poor coaching standards, lack of information and inadequate facilities. This has also resulted in Kenya being able to produce few world class footballers. The purpose of this thesis was to provide easily accessib...

  13. Flat belt continuously variable high speed drive

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley turbine'' (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the turbine'' corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the turbine'' belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  14. 77 FR 64183 - Notice of Availability of a Final General Conformity Determination for the California High-Speed...

    Science.gov (United States)

    2012-10-18

    ... California High-Speed Train System Merced to Fresno Section AGENCY: Federal Railroad Administration (FRA... Section of the California High-Speed Train (HST) System on September 18, 2012. FRA is the lead Federal... General Conformity requirements. The California High Speed Rail Authority (Authority), as the...

  15. 基于力觉交互的高速率精准操作技能训练方法%Precise high-speed motor skill training based on haptic interaction

    Institute of Scientific and Technical Information of China (English)

    卢可可; 刘冠阳; 张玉茹; 郭卫东; 周墨渊

    2011-01-01

    介绍了用力觉交互技术进行手眼协调高速率精准操作的动作技能训练方法.提出了记录播放和轨迹智能导引两种培训模式.在记录培训模式中,采用PD控制的方法使学员被动感受专家的运动信息.在智能导引纠正模式中,学员主动操作交互设备,计算机根据学员的操作情况控制交互设备输出导引力或纠正力.最后,采用Omega 3DOF建立了具备触觉显示和图形显示功能的"信封靶"描绘技能训练系统样机平台,分析了力模型参数对系统稳定性的影响.实验结果证明了培训方法的可行性.%A method for precise high-speed motor skill training based on a haptic interaction system is introduced. The record-play mode and intelligent guiding mode are proposed. In the record-play mode, the trainee is passive and experiences position playback of the expert's path with a Proportional-Derivative(PD) controller. In the intelligent guiding mode,the trainee traces the expert's path actively. The haptic device can output guidance force if the trainee cannot match the patch of the expert. Finally, the haptic interaction system for envelope drawing skill training is constructed with the haptic device Omega 3DOF. The parameters of the force model on system stability are analyzed. Experimental results demonstrate that the algorithm developed is feasible for precise high-speed motor skill training.

  16. A 3D model for coupling dynamics analysis of high-speed train/track system%一种高速列车-轨道三维空间耦合动力学模型

    Institute of Scientific and Technical Information of China (English)

    Liang LING; Xin-biao XIAO; Jia-yang XIONG; Li ZHOU; Ze-feng WEN; Xue-song JIN‡

    2014-01-01

    A 3D dynamic model of a high-speed train coupled with a flexible ballast track is developed and is presented in this study. In this model, each vehicle is modeled as a 42 degrees of freedom multi-body system, which takes into consideration the nonlinear dynamic characteristics of the suspensions. A detailed inter-vehicle connection model including nonlinear couplers and inter-vehicle dampers, and the linear tight-lock vestibule diaphragm is established to simulate the effect of the end connections of neighboring vehicles on dynamic behavior. The track is modeled as a traditional three-layer discrete elastic support model. The rails are assumed to be Timoshenko beams supported by discrete sleepers. Each sleeper is treated as an Euler beam and the ballast bed is replaced by equivalent rigid ballast bodies. The reliability of the present model is then validated through a detailed nu-merical simulation comparison with the commercial software SIMPACK, with the effect of the track flexibility on the train/track interaction being analyzed simultaneously. The proposed model is finally applied to investigate the difference between dynamic performances obtained using the entire-train/track model (TTM) and the single-vehicle/track model (VTM). Several key dynamic performances, including vibration frequency response, ride comfort, and curving performance, calculated by the two types of dynamic models are compared and discussed. The numerical results show that there is a significant difference between the dy-namic behaviors obtained by VTM and TTM, and that inter-vehicle connections have an important influence on the dynamic behavior of high-speed vehicles.

  17. 侧风风场特征对高速列车气动性能作用的研究%Research on Influence of Characteristics of Cross Wind Field on Aerodynamic Performance of a High-speed Train

    Institute of Scientific and Technical Information of China (English)

    毛军; 郗艳红; 杨国伟

    2011-01-01

    侧风风场特征,如均匀风和大气底层边界速度型对高速列车在侧风环境下运行的安全性评估有直接影响.为了准确地评估侧风对在平原上运行的高速列车的影响,基于三维定常可压缩流动的NS方程,采用SSTk-ω两方程湍流模型和有限体积法,对时速350 km的动车组在均匀风和大气底层边界速度型风场中的流场和气动力特性分别进行了数值模拟计算和分析.结果表明:对在平原上运行的高速列车而言,作用于列车的气动升力、侧向力及倾覆力矩均随侧风风向角的增大而迅速增大;当风场为大气底层边界速度型时,列车顶部与底部及两个侧面的压力差小于风场为均匀风时的压力差,侧向力及倾覆力矩均小于风场为均匀风时的力及力矩,升力则随侧风风向角的增加具有不确定性.采用均匀风场评估高速列车在平原侧风环境中运行的安全性,会高估侧风对列车运行安全影响的风险,使得过低地限制列车的安全行驶速度,从而影响列车的正常运行效率.建议采用大气底层边界速度型风场进行评估.%Characteristics of the cross wind field, such as uniform winds and lower atmospheric boundary layer winds,have directly influence on the operation safety of high-speed trains which run in the cross wind environment. In order to accurately assess the effect of cross winds on trains running on plains,on the basis of the three-dimensional steady compressible flow of NS equations, using the SST k-ω two-equation turbulence model and finite volume method, the flow field and aerodynamic characteristics of the high speed train running at 350 km/h in the cross wind field of uniform winds and lower atmospheric boundary layer winds were simulated numerically and analyzed. The results show as follows:For a high-speed train running under cross winds on a plain, the aerodynamic lift force, lateral force and overturning moment acting on the train

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

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2010-01-01

    A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine. A cascaded multilevel converter interface based on the MPMSGs is developed to synthesize a desired high ac sinusoidal...... reduce the fluctuation of the electromagnetic torque sum and results in a good performance for the MPMSGs structure. The simulation study is conducted using PSCAD/EMTDC, and the results verify the feasibility of this variable speed wind turbine based on multiple generators drive-train configuration....

  19. Design of a High Speed Adder

    OpenAIRE

    Aritra Mitra; Amit Bakshi; Bhavesh Sharma; Nilesh Didwania

    2015-01-01

    In this paper we have compared different addition algorithms such as Ripple Carry Adder, Carry Save Adder, Carry Select Adder, Carry Look Ahead Adder & Kogge Stone Adder for different performance parameters i.e. Area Utilization, Speed of operation and Power Consumption. A high speed Adder is then designed by merging Kogge Stone & Carry Select Algorithms. The circuits have been designed using Verilog HDL & Synthesize using TSMC 180 nm standard cell. The performance parameters are ...

  20. Compressibility, turbulence and high speed flow

    CERN Document Server

    Gatski, Thomas B

    2013-01-01

    Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and

  1. Real-time resource allocation algorithm on high-speed train mobile network%用于高速列车移动网络的资源分配实时算法

    Institute of Scientific and Technical Information of China (English)

    张永晖; 蒋新华; 林漳希

    2012-01-01

    High -speed train mobile scenarios is fitted to adopted multi-homing delay tolerant mobile network, alleviating high error rate and frequent disruptions effectively. However, its resource allocation algorithms on it are of computational complexity and poor real-time. Give an Initialization resource allocation algorithm, and ensure every step utility of processes non-decreasing with utility differential, gains O(n) algorithm time complexity.%误码率高、频繁中断的高速列车移动场景宜采用多宿主容迟网络.但其资源分配计算复杂,实时性较差.基于效用差分法设计初始化过程资源分配算法,以保证过程中每一步的效用单调不减,算法时间复杂度降至O(n).

  2. 基于模糊灰关联分析的高速列车运行状态识别%Running state recognition of high-speed train based on fuzzy grey correlation analysis

    Institute of Scientific and Technical Information of China (English)

    李家会; 金炜东; 熊莉英

    2014-01-01

    针对高速列车运行状态监测问题提出小波包能量熵与模糊灰关联度相结合的运行状态识别方法。对高速运行状态下列车10个关键部位传感器振动信号进行均匀分段及多层小波包分解,将小波包能量熵作为特征值;随机选取四种运行状态下各10段数据求其平均能量熵作为参考序列,其余数据能量熵作为待检测序列,采用灰色理论对参考、待检测序列进行模糊灰关联分析,获得待检测序列对各运行状态隶属度;实现对高速列车运行状态识别。实验结果表明,该方法能有效诊断高速列车运行状态,尤其小样本、故障特征不明显时明显优于支持向量机及概率神经网络方法。%Aiming at the high-speed train running state monitoring,a running state recognition method that couples wavelet packet energy entropy with fuzzy grey correlation degree technique was proposed.The vibration signals,which were acquired by ten sensors at the key positions of high-speed running train,were uniformly segmented and then decomposed by using multi-layer wavelet packets.The wavelet packet energy entropies,extracted from the vibration signals,were used as fault features.The average energy entropies of 10 pieces of random data of every running state were used as the reference sequences and the energy entropies of other data were used as the detected sequences.By analyzing the fuzzy grey correlation between the reference sequences and the detected sequences,the membership degree of the detected sequences belonging to four running states of the train was obtained and so the high-speed train running state recognition was realized.The experimental results show that the proposed method can effectively diagnose four running states of high-speed train,especially in the case of small samples and inconspicuous fault features.The proposed method is superior to the mothod of support vector machine and probabilistic neural network.

  3. Research on ergonomics experimental system of emergency operation for high-speed train%高速列车应急作业工效学实验系统研究

    Institute of Scientific and Technical Information of China (English)

    郭北苑; 巨建涛; 王雅楠; 方卫宁

    2013-01-01

    高速列车司机应急作业的可靠性对维护列车正点安全运行具有重要作用,但在实际列车运行中无法开展针对司机应急作业特性的工效学实验,因此有必要构建高速列车应急作业流程工效学实验系统,以便在实验室环境下开展相关研究.高速列车应急作业流程工效学实验系统由实验管理子系统、应急作业子系统和工效学数据采集子系统3个子系统组成,该系统设计中引入了故障注入技术,实现了故障注入、辅助处理等管理操作;系统还能完成司机应急作业操作中相关工效学数据采集功能.系统已成功应用于CRH2型高速列车应急作业流程工效学实验中.%Emergency operation reliability of the high-speed train drivers plays an important role in train safe operation maintenance, but in actual train operation, since the driver operation is forbidden from disturbance and the fault scenario is unable to be controlled, the ergonomics experiment about driver emergency operation characteristics can't be carried out, so it is necessary to construct an ergonomics experiment system with highspeed train emergency operation procedures and carry out some related experiments in laboratory environment. This system consists of experimental management subsystem, emergency operation subsystem and ergonomics data acquisition subsystem. In the design of the system, the fault injection technology is introduced to realize the two experimental management operations of fault injection and the auxiliary handle. Also this system can acquire the ergonomics data about the driver emergency operations. This system has been successfully used in the ergonomics experiment on the emergency operation procedures of CRH2 high-speed train.

  4. VLSI Circuits for High Speed Data Conversion

    Science.gov (United States)

    1994-05-16

    Meeting, pp. 289-292, Sept. 199 1. [4] Behzad Razavi , "High-Speed, Nigh-Resolution Analog-to-Digital Conversion in VLSI Technologies, Ph.D. Thesis... Behzad Razavi and Bruce A. Wooley, "Design Techniques for High-Speed, High- Resolution Comparators," IEEE J. Solid-State Circuits, vol. 27, pp. 1916-192...Dec. 1992. [8] Behzad Razavi and Bruce A. Wooley, "A 12-Bkt 5-MSamplesoc Two-Step CMOS A/D Converter," IEEE J. Solid-State Circuits, vol. 27, pp

  5. Wind environ ment research on the bridge section induced by high speed train under the bridge%桥下高速行驶列车对桥梁主梁位置风环境的影响研究

    Institute of Scientific and Technical Information of China (English)

    董国朝; 张建仁; 蔡春声; 韩艳

    2015-01-01

    The pressure and velocity fields will change greatly when the high-speed train is running through the bridge,and the intense ambient aerodynamic effects will be produced in areas around,thereby affecting the anti-wind safety of around buildings and structures.Due to the fact that there exist insurmountable technical prob-lems in using wind tunnel test,in this proposed project,the Fluent in CFD software was firstly used as the simu-lation platform with 'dynamic mesh'technology.Secondly,the UDF trains route procedures were programmed to monitor the speed and the pressure distribution through monitoring the bridge sections.Thirdly,the process when the high-speed trains cross through the bridge in different speeds was simulated under the situations of no cross-wind wind,small crosswind and the bridge design crosswind.Finally,the impact loads generated under three kinds of wind to the main section of the bridge were calculated in different crosswind speed.This paper studied the aerodynamic effects in various conditions of wind on the train to the bridge main sections,which provides a valuable reference and recommendation for bridge designers in the bridge design institution.%高速列车行驶时对周围的压力场和速度场产生强烈的变化,激烈的空气动力效应对周围环境产生一定作用,从而影响周围建筑和结构的抗风安全性。由于采用风洞试验测试手段研究此类问题在技术上尚存在难以克服的困难,因此,以计算流体力学Fluent软件为仿真平台,采用“动网格”技术,编写UDF列车行驶路线程序,对无侧风、微小侧风以及桥梁设计侧风速作用下高速列车以不同列车速度通过桥底的数值模拟,并对行车路线方向的桥梁主梁断面进行布点监测,给出高速列车通过桥底区域时的速度和压力空间分布规律,计算各侧风速、不同列车速度情况下列车风对桥梁主梁局部位置的冲击载荷,从而研究各

  6. Study on Causes and Prevention of Birds Striking at High-speed Railway Trains%高速铁路列车鸟击及防范研究

    Institute of Scientific and Technical Information of China (English)

    胡安华; 韩继公; 李阳

    2011-01-01

    There is no precedent study on birds striking at trains. This paper discusses the hazards of birds striking at trains, analysing the degree of the hazards, and gives a theoretical calculation formula to measure the hazards. Based on the records of birds striking, the causes of birds striking at trains are analysed. In order to prevent and control birds striking at trains, useful measures are suggested based on railway route selection, route environment, zoology and acclimatization of birds. These measures could ensure the safe operation of railways. Certain advice about further study is presented.%高速铁路列车鸟击及防范研究在国内外尚无先例.阐述高速铁路列车鸟击的危害,分析鸟击的危害并提出了理论计算模型及公式,论述鸟击的成因及防范鸟击的重要性.从高速铁路工程、沿线环境、生态及物种适应能力等方面系统性地提出了防范高速铁路列车鸟击的方法,力争减少鸟击,为高速铁路安全运营提供重要参考,为进一步研究提供了思路.

  7. Acute Response of Well-Trained Sprinters to a 100-m Race: Higher Sprinting Velocity Achieved With Increased Step Rate Compared With Speed Training.

    Science.gov (United States)

    Otsuka, Mitsuo; Kawahara, Taisuke; Isaka, Tadao

    2016-03-01

    This study aimed to clarify the contribution of differences in step length and step rate to sprinting velocity in an athletic race compared with speed training. Nineteen well-trained male and female sprinters volunteered to participate in this study. Sprinting motions were recorded for each sprinter during both 100-m races and speed training (60-, 80-, and 100-m dash from a block start) for 14 days before the race. Repeated-measures analysis of covariance was used to compare the step characteristics and sprinting velocity between race and speed training, adjusted for covariates including race-training differences in the coefficients of restitution of the all-weather track, wind speed, air temperature, and sex. The average sprinting velocity to the 50-m mark was significantly greater in the race than in speed training (8.26 ± 0.22 m·s vs. 8.00 ± 0.70 m·s, p sprinters achieve higher sprinting velocity and can run with higher exercise intensity and more rapid motion during a race than during speed training, even if speed training was performed at perceived high intensity.

  8. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating.

    Science.gov (United States)

    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-03-01

    The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs) were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour) for 8 weeks. Training intensity was determined within non-specific (cycling or running) and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m) and one non-specific (30s cycling or 200m running) all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa) and glucose (BGL) 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak) was significantly increased (+17%; p = 0.01) in both groups and highly correlated with the sprint performance (r = -0.71). BLa values decreased significantly (-18%, p = 0.02) after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04) in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group. Key pointsIn addition to a highly developed aerobic performance inline speed skaters also require a highly trained anaerobic capacity to be effective in the sprint sections such as the mass start, tactical attacks

  9. Analysis on Partial Friction Phenomenon of the Brake Disc for High-speed Train Brake%高速列车刹车片偏摩现象的研究

    Institute of Scientific and Technical Information of China (English)

    阎树田; 邹本涛; 高升

    2013-01-01

    Thermal structural coupled finite element method of brake pads for high speed train was given in this paper,calculate the boundary conditions, the finite element numerical simulation of brake pads was done by ABAQUS software and and make detailed analysis research of partial friction phenomenon for Brake pads.%研究了高速列车刹车片的热结构耦合有限元求解方法,确定其边界条件,利用ABAQUS软件对刹车片进行有限元数值模拟,并做了较为详细的分析研究,在此基础上分析了盘式制动器刹车片的偏摩现象.

  10. Optimization of the Sales Model and Sales strategies of the High Speed Train Ticket%高铁时代客票销售模式优化及策略探究

    Institute of Scientific and Technical Information of China (English)

    纪书景; 张进奎

    2015-01-01

    铁路售票全面实行实名制,实现计算机联网售票、发售异地票及车票的通签通退,并形成了车站窗口、互联网、自助售票机等多元化的格局,支付方式也从现金发展到网银、POS机等。由于售票系统设备滞后于IT的发展,售票网络时常发生故障,无法满足旅客的需求。所以,售票系统及设备应适时更新升级,不断提高从业人员素质,优化售票模式,才能满足旅客购票需求。%The sales model of the high speed train ticket was investigated. It is found out that the sales model of the high speed train ticket is diverse, including different selling services, selling places and ways of payment. It is also discovered that the ticket selling system is lagged behind the IT development and breaks down frequently, which is unable to fill the need of the customers. Thus, it is suggested that the ticket selling system should be updated on time, the quality of the sales staff should be improved and the sales model should be optimized.

  11. 高速列车车辆连接部位气动噪声数值模拟及降噪研究%Numerical simulation of aerodynamic noise and noise reduction of high-speed train connection section

    Institute of Scientific and Technical Information of China (English)

    黄莎; 梁习锋; 杨明智

    2012-01-01

    采用大涡模拟与声类比相结合的方法,对高速列车车辆连接部位不同尺寸参数时的气动噪声进行了数值模拟,并提出降噪改进方案.研究得到了高速列车以300km/h速度运行时车辆连接部位的气动噪声分布,结果表明:车辆连接部位气动噪声在很宽的频带内存在,是宽频噪声;各监测点气动噪声频谱在低频时幅值较大,随着频率的增大先增大后减小,1/3倍频程A声压级主要集中在315~1000Hz频率范围内;车辆连接部位不同尺寸参数中,气动噪声声压级幅值随着凹槽长度L和高度H的增大而有所增加;采用全风挡方案较无风挡时,有效避免气流在凹槽内剧烈扰动,气动噪声显著改善,声压级平均降幅约为9.4%,总声压级平均降幅4.27dBA;研究结果为低噪高速列车的初期研制设计提供科学依据.%Aerodynamic noise of high-speed train connection section with different parameters were simulated numerically adopting LES model companied with acoustic analogy and reducion improvement project was proposed. The aerodynamic noise distribution of high-speed train connection section at speed of 300km/h was obtained from the research, the results show that aerodynamic noise is a kind of wide frequency noise which exits in wide frequency band. The acoustic pressure amplitude of every test point is bigger at low frequency, increasing firstly then decreasing with the increase of frequency, and acoustic pressure level within 1/3 octave band frequency concentrates in the rage of 315~1000Hz; Among different parameters of train connection section, the acoustic pressure level amplitude increases with the increase of groove length and height; Compared with the project without windshield, the noise reduction effect of full windshield project is apparent, avoiding severe disturbance flow effectively, the average acoustic pressure level reductive amplitude is 9. 4% and the average total acoustic pressure level

  12. DAC 22 High Speed Civil Transport Model

    Science.gov (United States)

    1992-01-01

    Between tests, NASA research engineer Dave Hahne inspects a tenth-scale model of a supersonic transport model in the 30- by 60-Foot Tunnel at NASA Langley Research Center, Hampton, Virginia. The model is being used in support of NASA's High-Speed Research (HSR) program. Langley researchers are applying advance aerodynamic design methods to develop a wing leading-edge flap system which significantly improves low-speed fuel efficiency and reduces noise generated during takeoff operation. Langley is NASA's lead center for the agency's HSR program, aimed at developing technology to help U.S. industry compete in the rapidly expanding trans-oceanic transport market. A U.S. high-speed civil transport is expected to fly in about the year 2010. As envisioned, it would fly 300 passengers across the Pacific in about four hours at Mach 2.4 (approximately 1,600 mph/1950 kph) for a modest increase over business class fares.

  13. A high speed digital noise generator

    Science.gov (United States)

    Obrien, J.; Gaffney, B.; Liu, B.

    In testing of digital signal processing hardware, a high speed pseudo-random noise generator is often required to simulate an input noise source to the hardware. This allows the hardware to be exercised in a manner analogous to actual operating conditions. In certain radar and communication environments, a noise generator operating at speeds in excess of 60 MHz may be required. In this paper, a method of generating high speed pseudo-random numbers from an arbitrarily specified distribution (Gaussian, Log-Normal, etc.) using a transformation from a uniform noise source is described. A noise generator operating at 80 MHz has been constructed. Different distributions can be readily obtained by simply changing the ROM set. The hardware and test results will be described. Using this approach, the generation of pseudo-random sequences with arbitrary distributions at word rates in excess of 200 MHz can be readily achieved.

  14. 基于卫星导航系统的高速列车定位技术研究%Research on High-speed Train Positioning Technology Based on Satellite Navigation System

    Institute of Scientific and Technical Information of China (English)

    李卫东; 侯丽虹

    2016-01-01

    In this paper,we first introduce the development of a global navigation satellite system and analyze its per-formance.By combining our research results and the application of a train positioning technology that uses domestic and international satellite navigation systems,we divide the train positioning technology into four categories.Then, we comprehensively analyze the performance of the train positioning technology with respect to accuracy,effective-ness,and safety integrity;summarize the existing problems;and suggest solutions.Finally,we make recommenda-tions regarding the future development of high-speed train positioning technology based on satellite navigation.%首先,介绍全球卫星导航系统的发展状况,对比分析全球卫星导航系统性能。并结合国内外基于卫星导航系统的列车定位技术的研究成果和应用情况,将列车定位技术分为四大类。然后,从精准性、有效性、安全完整性三个方面对列车定位技术综合性能进行分析,总结其存在的问题并给出解决方法。最后对基于卫星导航的高速列车定位技术的未来发展趋势进行展望。

  15. High Speed and Slow Motion: The Technology of Modern High Speed Cameras

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter

    2011-01-01

    The enormous progress in the fields of microsystem technology, microelectronics and computer science has led to the development of powerful high speed cameras. Recently a number of such cameras became available as low cost consumer products which can also be used for the teaching of physics. The technology of high speed cameras is discussed,…

  16. The Effect of Two Speed Endurance Training Regimes on Performance of Soccer Players

    Science.gov (United States)

    Iaia, F. Marcello; Fiorenza, Matteo; Perri, Enrico; Alberti, Giampietro; Millet, Grégoire P.; Bangsbo, Jens

    2015-01-01

    In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg) reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6) or speed endurance maintenance (SEM; n = 7) training, three times per wk. SEP training consisted of 6–8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6–8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (prepeated sprint ability test (RSAt) by 2.5%. SEM training improved the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, psprint performances. In conclusion, these two training strategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles’ ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in trained young soccer players. PMID:26394225

  17. High speed technology development and evaluation

    Science.gov (United States)

    Parker, D. R.; Brown, E. R.; Dickson, J. F.

    1986-10-01

    Semiconductor technology suited to high on-board data handling rates was investigated. Very high speed discrete logic and high speed gate arrays; single chip digital signal processors and single chip floating point processing peripherals; and analog CCD technologies and custom designed CCD chips for synthetic aperture radar applications were assessed. The 2 micron CMOS technology is highly reliable, supporting semicustom design techniques. Process JGC, the CCD technology, is highly reliable except for tolerance to ionizing radiation. Reliability of the ECL 16-bit serial-parallel parallel-serial converter junction isolated bipolar process, process WZA, is compromised by a design error and oxide contamination contributing to high leakage levels. The bipolar circuit is tolerant to an ionizing radiation of 20kRad. Step stress environmental testing to 200 C produces no failures in CMOS and CCD technologies, but accelerates the degradation of the oxide contaminated bipolar process. All technologies are susceptible to single event upsets.

  18. 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....

  19. High-speed Power Line Communications

    Directory of Open Access Journals (Sweden)

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  20. 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,

  1. High speed adaptive liquid microlens array

    NARCIS (Netherlands)

    Murade, C.U.; van den Ende, Henricus T.M.; Mugele, Friedrich Gunther

    2012-01-01

    Liquid microlenses are attractive for adaptive optics because they offer the potential for both high speed actuation and parallelization into large arrays. Yet, in conventional designs, resonances of the liquid and the complexity of driving mechanisms and/or the device architecture have hampered a

  2. High speed multiplier design using Decomposition Logic

    Directory of Open Access Journals (Sweden)

    Ramanathan Palaniappan

    2009-01-01

    Full Text Available The multiplier forms the core of a Digital Signal Processor and is a major source of power dissipation. Often, the multiplier forms the limiting factor for the maximum speed of operation of a Digital Signal Processor. Due to continuing integrating intensity and the growing needs of portable devices, low-power, high-performance design is of prime importance. A new technique of implementing a multiplier circuit using Decomposition Logic is proposed here which improves speed with very little increase in power dissipation when compared to tree structured Dadda multipliers. Tanner EDA was used for simulation in the TSMC 180nm technology.

  3. 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.

  4. Sensor study for high speed autonomous operations

    Science.gov (United States)

    Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan

    2015-06-01

    As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.

  5. Requirements and structure design for high speed train windshield impact performance%高速动车风挡玻璃抗冲击性能要求与结构浅析

    Institute of Scientific and Technical Information of China (English)

    偰德翱; 臧曙光; 付静

    2016-01-01

    本文主要介绍了不同国家标准中对动车前风挡玻璃抗冲击试验方法的要求,以及试验所用弹体和弹速的相关规定,阐述了前风挡玻璃结构的组成及材料选择,以及不同材料对抗冲击性能所起到的作用。高速动车前风挡玻璃需要抵抗大的石块、飞鸟和小的碎石块的撞击,不同的冲机体对风挡玻璃的破坏作用不同。总体来说,抵抗飞鸟需要风挡玻璃有更大的刚度,抵抗大的石块冲击需要风挡玻璃采用更多的柔性中间层材料,依靠风挡玻璃的整体变形吸收冲机体的能量来阻止弹体穿透玻璃,抵抗小的碎石冲击需要外表面玻璃更厚且有高的表面压应力值和应力层深度。需要综合考虑3种弹体的破坏作用,来确定最优的风挡玻璃结构。%The impact test methods according to different national standards of high speed train windshield are introduced, described the detail of impact projectiles and impact speed requirement,and expounded the principle of design EMU windshield glass structure and composition of material selection.Explain different materials effect impact performance.High-speed train windshield need to resist large stones,birds and small ballast,different projectile will cause different damage of windscreen. Generally,the windshield stiffness more higher more better for resistance bird impact; but for resistance hard projectile impact,use more flexible middle layer material is better, interlayer and deformation of windshield will absorb impact energy and will prevent the hard projectile penetrates the glass;the thickness of outer side glass surface compressive stress value and the depth of the stress are important for resistant gravel impact. Need to consider the damage effect of 3 projectiles,to determine the optimal structure of the windshield glass.

  6. Test and analysis of high-speed trains induced environmental noise and sound barriers%高速列车引起的环境噪声及声屏障测试分析

    Institute of Scientific and Technical Information of China (English)

    陈建国; 夏禾; 蔡超勋; 于秀梅

    2011-01-01

    对武广客运专线上高速运行列车引起的环境噪声及声屏障降噪效果进行了实测,测得大量噪声数据.通过分析得到以下结论:高速列车的机车辐射噪声随列车速度的增大而增大;通过路基段时的辐射噪声为82.8~91.8 dB(A),通过桥梁段时为79.3~89.6 dB(A),随着桥梁和路基高度的逐渐增大,辐射噪声略有减小的趋势;噪声频率主要集中在低频段(f=40~80 Hz)和中频段(f=500~8 000 Hz),与桥梁区段相比,路基区段随频率的增加声能量衰减较为平缓.近期路基段铁路边界噪声值在60~65 dB(A),桥梁段为55~60dB(A);中期(2018年)边界噪声的预测噪声值较近期值有明显增大,最大值接近规范限值.路基声屏障降噪效果为6~8 dB(A),桥梁声屏障降噪效果为6~7 dB(A);声屏障越高降噪效果越明显,3.15 m高声屏障降噪效果较2.65 m高声屏障提升2 dB(A)左右.%A field experiment was carried out at the Wuhan-Guangzhou high-speed railway to study the train-induced environment noise and noise mitigation effect of the sound barriers.The measured results show that the noise emitted by the train vehicles was increase with train speed, it was 82.8~91.8 dB(A) when the train ran on the ground track, and 79.3~89.6 dB (A) when the train ran on the bridge; the emitted noise of the train was decrease with the height of the bridge and the subgrade; the noise was mainly at low frequency (f= 40~ 80 Hz)and medium frequency (f=500~ 8 000 Hz); The acoustic energy increasing with frequency on ground section attenuated more gently than on the bridges.Currently, the boundary noise alongside the ground track was 60~65 dB(A), and on bridges 55~60 dB(A); the predicted boundary noise alongside ground track by the year of 2018 will be much higher than present one, whose maximum value will be up to the code allowances.The noise reduction of sound barriers is 6~8 dB(A) on ground track, and 6~7 dB(A) on bridges.The higher

  7. High speed printing with polygon scan heads

    Science.gov (United States)

    Stutz, Glenn

    2016-03-01

    To reduce and in many cases eliminate the costs associated with high volume printing of consumer and industrial products, this paper investigates and validates the use of the new generation of high speed pulse on demand (POD) lasers in concert with high speed (HS) polygon scan heads (PSH). Associated costs include consumables such as printing ink and nozzles, provisioning labor, maintenance and repair expense as well as reduction of printing lines due to high through put. Targets that are applicable and investigated include direct printing on plastics, printing on paper/cardboard as well as printing on labels. Market segments would include consumer products (CPG), medical and pharmaceutical products, universal ID (UID), and industrial products. In regards to the POD lasers employed, the wavelengths include UV(355nm), Green (532nm) and IR (1064nm) operating within the repetition range of 180 to 250 KHz.

  8. Safety issues in high speed machining

    Science.gov (United States)

    1994-05-01

    There are several risks related to High-Speed Milling, but they have not been systematically determined or studied so far. Increased loads by high centrifugal forces may result in dramatic hazards. Flying tools or fragments from a tool with high kinetic energy may damage surrounding people, machines and devices. In the project, mechanical risks were evaluated, theoretic values for kinetic energies of rotating tools were calculated, possible damages of the flying objects were determined and terms to eliminate the risks were considered. The noise levels of the High-Speed Machining center owned by the Helsinki University of Technology (HUT) and the Technical Research Center of Finland (VTT) in practical machining situation were measured and the results were compared to those after basic preventive measures were taken.

  9. High speed, high current pulsed driver circuit

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. 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.

  11. THE EFFECT OF ROPE JUMPING TRAINING OF DIFFERENT SPEEDS ON ANAEROBIC POWER

    OpenAIRE

    ŞAHİN, Gülşah

    2017-01-01

    The objective of this study was to compare the effect of rope jumpingtraining on anaerobic vertical, horizontal, mean and peak power of rope jumpingat different speeds in trained females. The study was comprised of 20 trainedfemales as the low-speed jumping group (n=10, mean age 21.4±2.3 years, body weight54.30±6.03 kg, height 161.30±6.99 cm) and the high-speed jumping group (n=10,mean age 21±1.8 years, body weight: 56.50±5.91 kg, height 163.20±7.02 cm). Thejumping speed was adjusted using a ...

  12. Development of a Revolutionary High Speed Spindle

    Science.gov (United States)

    Agba, Emmanuel I.

    1999-01-01

    This report presents the development of a hydraulic motor driven spindle system to be employed for high speed machining of composite materials and metals. The spindle system is conceived to be easily retrofitted into conventional milling machines. The need for the hydraulic spindle arises because of the limitations placed on conventional electric motor driven spindles by the low cutting power and the presence of vibrational phenomena associated with voltage frequency at high rotational speeds. Also, the electric motors are usually large and expensive when power requirements are moderately high. In contrast, hydraulic motor driven spindles promise a distinct increase in spindle life over the conventional electric motor driven spindles. In this report, existing technologies applicable to spindle holder for severe operating conditions were reviewed, conceptual designs of spindle holder system were developed and evaluated, and a detailed design of an acceptable concept was conducted. Finally, a rapid prototype of the design was produced for design evaluation.

  13. Nanometer lapping technology at high speed

    Institute of Scientific and Technical Information of China (English)

    YANG JianDong; TIAN ChunLin; WANG ChangXing

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abrasives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  14. Nanometer lapping technology at high speed

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abra-sives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  15. 高速列车纵向对称面气动噪声计算及外形优化%Numerical prediction of aerodynamic noise radiated from longitudinal symmetric plane of high-speed train and shape optimization

    Institute of Scientific and Technical Information of China (English)

    肖友刚; 张平

    2013-01-01

    将大涡模拟法与Lighthill-Curle声学比拟理论相结合,计算了高速列车纵向对称面的气动噪声,探明了纵向对称面气动噪声的频谱特性及其变化规律,得出了车辆连接处的优化外形.结果表明,低频时,气动噪声幅值较大,随着频率升高,幅值下降.当列车运行速度一定时,距离气动噪声源越远,声压的衰减幅度越少.随着列车运行速度增加,距离气动噪声源越远,声压的增幅越小.脉动压力是气动噪声的源,在车辆连接处采用平滑的Nurbs曲线过渡,以减少列车运行过程中产生的脉动压力,能有效降低气动噪声.%The aerodynamic noise spectra of longitudinal symmetric plane of high-speed train were calculated and clarified by large eddy simulation and Lighthill-Curle acoustic theory. The optimal aerodynamic shape at vehicle junctions was got. The results show that the noise level of the aerodynamic noises is reduced greatly with the increase of frequency. When the train velocity is unchanged, the farther away from the aerodynamic noise sources, the less the attenuation rate of total noise level. With increase of the train velocity, the farther away from noise sources, the less the noise level increase. The fluctuation pressure is the source of aerodynamic noise, which can be reduced by using nurbs curve at vehicle junctions.

  16. High-speed pulse-shape generator, pulse multiplexer

    Science.gov (United States)

    Burkhart, Scott C.

    2002-01-01

    The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

  17. On the Comparison of Dynamic Effects on Bridges of Maglev Trains with High-Speed Wheel/Rail Trains%磁浮列车与轮轨高速列车对线桥动力作用的比较研究

    Institute of Scientific and Technical Information of China (English)

    翟婉明; 赵春发; 蔡成标

    2001-01-01

    以德国Transrapid高速磁浮列车和日本新干线高速列车 为基础,通过建立高速磁浮、轮轨列车与线桥动态相互作用模型,计算了不同行车速度(100 ~500 km/h)和不同桥跨(12~32 m)情形下高速列车与桥梁结构的动力响应,并进行了细致 的对比分析。结果表明:磁浮列车在高速特别是超高速运行条件下的乘坐舒适性明显优于轮 轨高速列车;磁浮与轮轨高速列车作用于轨道的每延米荷载大体相当;高速磁浮列车对小跨 度(22 m以下)桥梁的动力作用小于轮轨高速列车,而对中等跨度尤其是大跨度桥梁,轮轨高 速列车较高速磁浮列车具有明显的优越性。%A maglev vehicle/girder interaction model and a dynamic model of wheel/rail train and bridge are established,based on the configuration of Germ an high-speed maglev system and Japanese Shinkansen system,respectively.Dynamic responses of high-speed trains passing through a bridge have been calculated a nd compared for various running speeds and various spans of bridges.Numerical re sults show that the ride comfort of the maglev vehicle is much better than that of the wheel/rail vehicle,especially in the situation of extraordinary high-spe ed operation,the dynamic effect on bridge of the maglev train is smaller than th at of the wheel/rail train only when the span length of bridge is below 22 m,but for the bridge with middle and large spans the dynamic effect of the maglev tra in will be stronger than that of the wheel/rail train in high-speed operations.

  18. 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.

  19. 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).

  20. High-speed tensile test instrument.

    Science.gov (United States)

    Mott, P H; Twigg, J N; Roland, D F; Schrader, H S; Pathak, J A; Roland, C M

    2007-04-01

    A novel high-speed tensile test instrument is described, capable of measuring the mechanical response of elastomers at strain rates ranging from 10 to 1600 s(-1) for strains through failure. The device employs a drop weight that engages levers to stretch a sample on a horizontal track. To improve dynamic equilibrium, a common problem in high speed testing, equal and opposite loading was applied to each end of the sample. Demonstrative results are reported for two elastomers at strain rates to 588 s(-1) with maximum strains of 4.3. At the higher strain rates, there is a substantial inertial contribution to the measured force, an effect unaccounted for in prior works using the drop weight technique. The strain rates were essentially constant over most of the strain range and fill a three-decade gap in the data from existing methods.

  1. High speed functional magnetic resonance imaging

    CERN Document Server

    Gibson, A M

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated by reference, within the Magnetic Resonance Centre at the University of Nottingham during the period from October 1998 to October 2001. This thesis documents the implementation and application of a novel high-speed imaging technique, the multi-slice, echo shifted, echo planar imaging technique. This was implemented on the Nottingham 3 T imaging system, for functional magnetic resonance imaging. The technique uses echo shifting over the slices in a multi-slice echo planar imaging acquisition scheme, making the echo time longer than the repetition time per slice. This allows for rapid volumar sampling of the blood oxygen level dependent effect in the human brain. The new high-speed technique was used to investigate the variability of measuring the timing differences between haemodynamic responses, at the same cortical location, to simple cued motor tasks. The technique was also used in an investigation into motor cortex functional connect...

  2. High-speed massively parallel scanning

    Science.gov (United States)

    Decker, Derek E.

    2010-07-06

    A new technique for recording a series of images of a high-speed event (such as, but not limited to: ballistics, explosives, laser induced changes in materials, etc.) is presented. Such technique(s) makes use of a lenslet array to take image picture elements (pixels) and concentrate light from each pixel into a spot that is much smaller than the pixel. This array of spots illuminates a detector region (e.g., film, as one embodiment) which is scanned transverse to the light, creating tracks of exposed regions. Each track is a time history of the light intensity for a single pixel. By appropriately configuring the array of concentrated spots with respect to the scanning direction of the detection material, different tracks fit between pixels and sufficient lengths are possible which can be of interest in several high-speed imaging applications.

  3. The Aerodynamics of High Speed Aerial Weapons

    OpenAIRE

    Prince, Simon A.

    1999-01-01

    The focus of this work is the investigation of the complex compressible flow phenomena associated with high speed aerial weapons. A three dimen- sional multiblock finite volume flow solver was developed with the aim of studying the aerodynamics of missile configurations and their component structures. The first component of the study involved the aerodynamic investigation of the isolated components used in the design of conventional missile config- urations. The computati...

  4. A High-Speed Information Retrieval System

    Institute of Scientific and Technical Information of China (English)

    SHI Shu-dong; LI Zhi-tang

    2004-01-01

    We cleveloped a high-speed information retrieval system. The system hased on the IXP 2800 is one of the dedicute device. The velocily of the information retrieval is 6.8 Gb/s. The protocol support Telnet, FTP, SMTP, POP3 etc. various networks protocols. The information retrieval supports the key word and the natural language process. This paper explains the hardware system, software system and the index of the performance.

  5. 49 CFR 38.175 - High-speed rail cars, monorails and systems.

    Science.gov (United States)

    2010-10-01

    ... but not limited to those using “maglev” or high speed steel-wheel-on-steel rail technology, and monorail systems operating primarily on dedicated rail (i.e., not used by freight trains) or guideway,...

  6. Study on Sound Insulation and Lightening Design of Layered Composite Structures for High-speed Trains%高速列车车体轻量化层状复合结构隔声设计

    Institute of Scientific and Technical Information of China (English)

    伏蓉; 张捷; 姚丹; 肖新标; 金学松

    2016-01-01

    随着高速列车车体结构轻量化的发展,层状复合结构车体在高速列车上得到广泛应用,提高层状复合结构的隔声性能,是高速列车减振降噪的关键技术。基于传递矩阵法,建立“铝板+多孔材料层+空气层+碳纤维增强板”的典型高速列车层状复合结构车体隔声计算分析模型,并分析多孔材料和空气层对层状复合结构车体隔声性能的影响。结果显示,混响声场激励下,在铝板和碳纤维增强版之间仅增加空气层只能提高车体结构高频隔声量,低频部分会由于“板-空气-板”的系统耦合共振,形成显著吻合谷,导致其隔声性能在吻合谷频率处大幅下降。对此,利用多孔材料吸声原理,提出在空气层中增加吸声材料层,抑制隔声吻合低谷,通过优化设计,得出“铝板+空气层+吸声材料+空气层+碳纤维增强板”的优化结构形式,在实现车体轻量化目标同时,可有效提高其隔声性能。%The layered composite structure is widely used for the weight reduction in high-speed trains. Improving the sound insulation properties of the composite structure is the key technology for vibration and noise reduction of high-speed trains. In this paper, based on the transfer matrix method, a model of typical composite structure made of aluminum plate, porous material layer, air layer and carbon-fiber reinforced plate for high-speed trains was established. Influence of the property of the air layer and the porous material on the sound insulation performance of the composite structure was analyzed by numerical calculations. The results show that the air layer between the aluminum panel and the carbon fiber reinforced polymer panel can hardly improve the sound insulation property of the composite structure in the lower frequency band under a diffusing field excitation. Instead, the transmission loss curves have acoustic valleys at some specific frequencies

  7. 高速铁路桥梁及场地土交通振动分析%Analysis of bridge-ground vibrations induced by moving loads of high-speed train

    Institute of Scientific and Technical Information of China (English)

    朱志辉; 余志武; 蒋丽忠; 高芒芒

    2012-01-01

    A three-dimensional FEM analytical model for train-bridge-pier-pile-soil coupled vibration system considering soil-structure interactions is built using a high-speed train car simulated by 32m long simply supported beam as example. The car was modeled as a multiple degrees of freedom system with two layer suspensions. Soil foundation data were measured on-site at the Beijing-Shanghai high-speed railway, and as part of the soil modeling, visco-elastic artificial boundary elements were employed to simulate the soil in semi-infinite domain. Contacts between train-car wheels and the underlying rails were simulated using 3D dynamic contact elements which were based on a Coulomb's contact algorithm. The influences of the underlying structures, such as piers and piles, on vehicle-bridge coupled vibrations were analyzed, and the effects of the coupled vibrations on the vibrations of the surrounding soil were studied too. The results show that the coupled vehicle-bridge vibrations are significantly influenced by nearby piers and piles. Furthermore, vertical vibration levels are found to attenuate with increasing distance to foundation, whereas attenuation of horizontal vibrations is not so obvious. The high frequency components in field vibration attenuate more rapidly than low frequency ones, therefore remote field vibrations contain dominant low frequency components. Field vibration levels do not linearly correlate with vehicle speed, but they are largely affected by their superstructure vibrations.%以高速铁路32 m单箱单室简支梁为例,建立了考虑土-结构动力相互作用的车-桥-墩-桩-土耦合振动系统整体三维有限元分析模型.车辆采用具有二系悬挂的多自由度车辆模型,场地土采用京沪高速铁路沿线实勘软土地基土层数据,在土体截断处采用粘弹性人工边界模拟半无限域土体,采用基于库伦接触算法的动力三维接触单元模拟轮轨接触.分析了桥墩和桩基等下部结构对

  8. Speed endurance training is a powerful stimulus for physiological adaptations and performance improvements of athletes

    DEFF Research Database (Denmark)

    Iaia, F. M.; Bangsbo, Jens

    2010-01-01

    performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle......The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain...

  9. 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.

  10. An Algorithm for the Optimal Matching Speeds of Passenger and Freight Trains in Mixed Operations

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper models the calculation of the optimal matching speeds of passenger and freight trains with various stage control methods for speed in mixed operations, presents a algorithm for the solution and justifies it with a practical example.

  11. 高速列车车端关系综合试验台试验研究%Experimental study on the comprehensive test bench of high-speed train cabinet-end relationship

    Institute of Scientific and Technical Information of China (English)

    王英波; 李明; 丛大成; 许宏光; 韩俊伟

    2012-01-01

    To verify whether the comprehensive test bench of cabinet-end relationship for high-speed train can meet the demand or not, the positioning precision, maximum motion range, forward kinematics, dynamic tracking performance and maximum output speed tests were carried out. The results indicate that the maximum positioning error of translational motion is 0. 1 mm and the maximum positioning error of rotation motion is 0. 1 °, far superior to the actual demand. The forward kinematics of the Stewart parallel manipulator is precise enough and ean be used for monitoring the real-time state of the system. In the dynamic tracking test, the maximum aptitude attenuation and the maximum phase lag occur in the Ydirection, 0. 755 dB and 25.92°, respectively, significantly better than the amplitude attenuation 3 dB and phase lag 90°. The maximum output speed of three translational motion can meet the 0. 2 m/s requirement. The results show that cabinet-end relationship comprehensive test bench can fully meet the demand of the high-speed train cabinet-end relationship test and has space for further improving performance.%为了验证基于Stewart并联机器人的车端关系综合试验台能否满足车端关系试验的要求,进行静态定位精度、最大运动范围、运动学正解、动态跟踪特性和最大输出速度试验.结果表明,试验台最大平移运动定位误差0.1mm,最大旋转运动定位误差0.1°,远优于车端关系试验实际需求,Stewart并联机器人运动学正解精确,可用于系统状态实时监控;动态跟踪特性中,最大幅值衰减和相位滞后均发生在Y向,分别为0.755dB和25.92°,明显优于幅值衰减3dB和相位滞后小于90°的要求;三向平移运动最大输出速度均能够达到0.2m/s的要求.表明车端关系综合试验台完全能够满足高速列车车端关系试验的要求,并且具备进一步提升性能的空间.

  12. Failure Analysis of High-speed Train Body Beam of A7N01S Aluminum Alloy%高速列车A7N01S铝合金车体横梁失效原因分析

    Institute of Scientific and Technical Information of China (English)

    张明月; 谭梦蕾; 张民安; 陈辉; 周弋琳; 刘金博; 陈煜

    2013-01-01

    When welded with a reinforcement plate, the body beam of a high-speed train was found to have cracked and even fractured around the weld seams. The failure cause was investigated through macroscopic feature, metallographic examination, chemical composition analysis and fracture morphology etc. Results show that the cracking is mainly caused by liquation crack in the mother material near the weld, solidification cracking in the weld, incomplete fusion and stomata etc. High welding energy, unreasonable welding parameters and improper welding structure design are main reasons for those deficiencies.%某型高速列车车体横梁与补强板的焊缝处出现裂纹并发生断裂.为确定失效机理,对断裂部位宏观形貌、金相组织、化学成分及断口形貌等进行分析.研究表明,横梁失效主要是由近缝区母材的液化裂纹、焊缝处的结晶裂纹、未熔合和气孔等缺陷引起的.这些缺陷主要是源于焊接线能量过大、其它焊接参数选择不当以及焊接结构设计不合理.

  13. 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...

  14. Optimization and Verification of HMT Planetary Gear Train in High-speed Transplanter%高速插秧机 HMT 行星轮系机构的优化设计

    Institute of Scientific and Technical Information of China (English)

    李革; 李明杰; 俞高红

    2014-01-01

    This paper discussed the problem:The key to solve the hardness of the design of hydraulic mechanical trans-mission ( HMT) planetary gear train in High speed transplanter .The paper wrote with the design goal of the minimum volume of planetary gear train from some aspects , which is to meet the transmission requirements , reduce the weight , en-sure the tooth root bending fatigue strength and gear surface contact fatigue strength .With the establishment of objective function and constraint function , an optimum design math-model has been set up .By fmincon function for solving con-strained nonlinear programming problems in MATLAB optimization toolbox , the optimization problem was solved .At the same time , the specific steps of optimization of planetary gear system are given .Such as a real example calculation and a-nalysis of HMT planetary gear train , compared the optimization design results with the conventional design method re-sults, the volume and weight of HMT planetary gear train decreases by 24%, the space of assembly is reduce , what’ s more, the strength of the gear transmission is within the allowable range .%针对高速插秧机液压机械无级变速器( HMT )行星齿轮系设计困难的问题,从满足传动要求,保证齿轮弯曲疲劳强度、齿面接触疲劳强度及减轻质量的角度出发,以行星齿轮系体积最小或质量最轻为优化目标,确立目标函数与约束条件,建立最优设计的数学模型,选用 MATLAB 优化工具箱中求解约束非线性规划问题的 fmin-con函数进行优化问题的求解。通过对一种高速插秧机HMT行星齿轮系的实例设计,优化设计与常规设计方法得出的结果相比,优化设计后HMT行星齿轮系齿轮的体积减小了22.4%,质量减轻明显。

  15. Propagation Measurement on Earth-Sky Signal Effects for High Speed Train Satellite Channel in Tropical Region at Ku-Band

    Directory of Open Access Journals (Sweden)

    Abdulmajeed H. J. Al-Jumaily

    2015-01-01

    Full Text Available Recent advances in satellite communication technologies in the tropical regions have led to significant increase in the demand for services and applications that require high channel quality for mobile satellite terminals. Determination and quantification of these requirements are important to optimize service quality, particularly in the Malaysian region. Moreover, the tests on current satellite propagation models were carried out at temperate regions whose environmental characteristics are much different from those in Malaysia. This difference renders these propagation models inapplicable and irrelevant to tropical regions in general. This paper presents the link characteristics observations and performance analysis with propagation measurements done in tropical region to provide an accurate database regarding rain and power arches supply (PAs attenuations in the tropics for mobile scenarios. Hence, an extension for improving the performance assessment and analysis of satellite/transmission has been achieved. The Malaysia propagation measurement for mobile scenario (Malaysia-PMMS enables first-hand coarse estimation and attenuation analysis, because the attenuation resulting from rain and PAs becomes easily amenable for measurement. Parallel to that, the measured attenuation has been compared with that of the simulated output at noise floor level. The underlying analytical tool is validated by measurements specific at tropical region, for dynamic model of mobile satellite links operating at higher than 10 GHz.

  16. Using More Data to Speed-up Training Time

    CERN Document Server

    Shalev-Shwartz, Shai; Tromer, Eran

    2011-01-01

    In many recent applications, data is plentiful. By now, we have a rather clear understanding of how more data can be used to improve the accuracy of learning algorithms. Recently, there has been a growing interest in understanding how more data can be leveraged to reduce the required training runtime. In this paper, we study the runtime of learning as a function of the number of available training examples, and underscore the main high-level techniques. We provide some initial positive results showing that the runtime can decrease exponentially while only requiring a polynomial growth of the number of examples, and spell-out several interesting open problems.

  17. Design of noise barrier inspection system for high-speed railway

    Science.gov (United States)

    Liu, Bingqian; Shao, Shuangyun; Feng, Qibo; Ma, Le; Cholryong, Kim

    2016-10-01

    The damage of noise barriers will highly reduce the transportation safety of the high-speed railway. In this paper, an online inspection system of noise barrier based on laser vision for the safety of high-speed railway is proposed. The inspection system, mainly consisted of a fast camera and a line laser, installed in the first carriage of the high-speed CIT(Composited Inspection Train).A Laser line was projected on the surface of the noise barriers and the images of the light line were received by the camera while the train is running at high speed. The distance between the inspection system and the noise barrier can be obtained based on laser triangulation principle. The results of field tests show that the proposed system can meet the need of high speed and high accuracy to get the contour distortion of the noise barriers.

  18. High-Speed Propeller for Aircraft

    Science.gov (United States)

    Sagerser, D. A.; Gatzen, B. S.

    1986-01-01

    Engine efficiency increased. Propeller blades required to be quite thin and highly swept to minimize compressibility losses and propeller noise during high-speed cruise. Use of 8 or 10 blades with highpropeller-power loading allows overall propeller diameter to be kept relatively small. Area-ruled spinner and integrated nacelle shape reduce compressibility losses in propeller hub region. Finally, large modern turboshaft engine and gearbox provide power to advanced propeller. Fuel savings of 30 to 50 percent over present systems anticipated. Propfan system adaptable to number of applications, such as highspeed (subsonic) business and general-aviation aircraft, and military aircraft including V/STOL.

  19. ANALYSIS ON FLUID-STRUCTURE INTERACTION VIBRATION OF HIGH-SPEED TRAIN PASSING BY SOUND BARRIER%高速列车通过声屏障的流固耦合振动响应分析

    Institute of Scientific and Technical Information of China (English)

    张亮; 张继业; 张卫华

    2014-01-01

    Based on the three-dimensional unsteady incompressible Navier-Stokes equation and the turbulent model of k-two equations,and by using the CFD software FLUENT,this paper simulated numerically the aerody-namic characteristics of sound barriers on embankment when the train passes,and studied the changes of pressure fluctuation on sound barrier.The numerical calculation model of a high-speed train passing by the sound barrier on embankment was established,and the aerodynamic pressures on sound barrier were simulated by using the sliding mesh technology in FLUENT,considering the speeds of train 200km/h,250km/h,300km/h and 350km/h,respectively.The magnitude and variation of aerodynamic forces on sound barrier were obtained,and the characteristics of aerodynamic pressure along the vertical and longitude directions of the sound barrier were ana-lyzed.The relationship between the amplitude of the sound barrier pressure and train’s speed was fitted.The structural analysis model of sound barrier was established by ANSYS Workbench,and then the aerodynamic pres-sure was loaded to the sound barrier and the modal analysis and transient dynamic response were researched.%基于三维、非定常、不可压缩Navier-Stokes方程以及k-ε两方程湍流模型,利用计算流体软件FLU-ENT,对列车通过时路堤声屏障气动力特性进行数值仿真,研究了声屏障上脉动力的变化.建立了高速列车通过路堤声屏障的数值计算模型,采用FLUENT中的滑移网格技术,对声屏障时产生的气动力进行数值模拟,列车速度分别为200km/h、250km/h、300km/h、350km/h.通过计算得到不同列车速度下声屏障上气动力的大小和变化情况,分析了气动力沿声屏障垂向和声屏障纵向的变化规律,并拟合了声屏障压力波幅值与列车速度的关系式.在ANSYS Workbench软件中建立了声屏障的结构计算模型,将声屏障上的气动力作为外部荷载加到声屏障上,对其

  20. THE CORRELATION BETWEEN THE PHYSICAL TRAINING AND THE SPORT PERFORMANCES IN SPEED SKATING AT CHILDREN

    Directory of Open Access Journals (Sweden)

    VAIDA Marius

    2010-04-01

    Full Text Available Sport practice at an early age is a problem of high actuality, this being debated intensely by specialists,the solving of the problem in cause being appreciated as a highly important factor in the general conception ofthe complex process of sport practice, in this process a very important role being held by the physical training.The present paper approaches the complex problem of the connection between the physical training andthe sport performances at children through an experiment realized on 6 speed skaters, 4 boys and 2 girls, withages of 8-9, experiment that had as purpose the demonstration of the importance of the multilateral physical training at skaters of an early age, of course without excluding the importance of the other factors necessary for superior results.Through the obtained results we proved that there is a direct connection between the physical training and the sport performances at children, knowing that the superior results in speed skating, on a long period, depend also by the training quality at an early age

  1. Dynamics of high speed wheel/rail system and its modelling

    Institute of Scientific and Technical Information of China (English)

    ZHANG ShuGuang; ZHANG WeiHua; JIN XueSong

    2007-01-01

    With the fast increasing of train speed the interactions among the train, the track, and the power catenary system become very strong. Such interactions are also strongly coupled with the action of high speed airflow due to the high speed running. Hence, the existing research methods and numerical algorithms of railway vehicle/track systems are not fully available for characterizing the transient dynamic and long-term behaviors of train/track at higher speed. The present paper reviews the existing studies on coupling dynamics of railway vehicle/track, and clarifies their advantages and disadvantages and then puts forward an innovation stratagem for high speed railway based on rolling contact of wheel/rail systems. In the innovation stratagem, a comprehensive dynamic model of wheels/rails systems is developed to simultaneously consider the track system, the train, the rolling contact of wheel/rail, the catenary/pantograph system, and the high speed airflow with the train. The motion equations of the subsystems and their coupling boundaries are given and discussed. For the reliability and safety of the high speed train in service, the long-term behavior of the structures of the train and the track is considered in the comprehensive model. Moreover, a generalized failure model, considering the structures and the materials and working in the comprehensive dynamic model of wheels/rails system, as well as the simulation system of structure failure of the high speed train/track is established.Consequently, the present studies on the dynamics of the coupled vehicle/track will be further and largely extended.

  2. 高速列车驾驶台多功能显示器虚拟仿真%Simulation of multi-function displays in high-speed train cab

    Institute of Scientific and Technical Information of China (English)

    唐晴; 何润; 江永全; 李柯

    2013-01-01

    This paper studied on the virtual simulation technology of high-speed train cab based on XNA platform,especially the implementation of the multi-function displays (MFD) of the virtual cab in the virtual three-dimensional scene.It was mainly involved the creation,driving and interaction of the virtual monitor.The off-screen rendering technology was used which was based on XNA platform,dynamic parameter-driven MFD and model picking up algorithm.These methods could vividly implement the real-time display of the highspeed train cab operation information and the man-machine interactive control,make the virtual scene much more lifelike and immersive.%本文研究了基于XNA平台的高速列车驾驶台虚拟仿真技术,着重介绍了虚拟驾驶台中多功能显示器在虚拟三维场景中的实现方法.主要涉及虚拟显示器的创建、驱动及交互等功能的实现方法,采用基于XNA平台的离屏渲染技术、动态参数驱动MFD显示和模型拾取算法,逼真地实现了实时显示高速列车驾驶台运行信息和人机交互,提高了虚拟场景的真实感、沉浸感.

  3. THE CORRELATION BETWEEN THE PHYSICAL TRAINING AND THE SPORT PERFORMANCES IN SPEED SKATING AT CHILDREN

    National Research Council Canada - National Science Library

    VAIDA Marius

    2010-01-01

    ... training.The present paper approaches the complex problem of the connection between the physical training andthe sport performances at children through an experiment realized on 6 speed skaters, 4 boys and 2...

  4. High-speed train Oslo-Berlin

    DEFF Research Database (Denmark)

    Jespersen, Per Homann

    Indlæggets baggrund og formål I det såkaldte COINCO-projekt, et INTERREG-projekt støttet af regioner og byer mellem Oslo og Berlin, er der udviklet en strategi for et tættere samarbejde i korridoren (Jespersen et al. 2007). Udbygning af infrastrukturen for passagerer og gods er en væsentlig del h...

  5. 内外激励下高速列车齿轮箱箱体动态响应分析%Dynamic Response Analysis of Gearbox Housing System Subjected to Internal and External Excitation in High-speed Train

    Institute of Scientific and Technical Information of China (English)

    黄冠华; 王兴宇; 梅桂明; 张卫华; 梁树林

    2015-01-01

    对高速列车齿轮箱箱体结构的动态响应特性进行分析。对齿轮传动系统内部和外部动态激励进行数值模拟,建立考虑轮齿啮合的高速列车动力车整车动力学模型,内部激励主要考虑齿轮的时变啮合刚度、轮齿啮合阻尼和传递误差,外部激励主要考虑异步电动机的谐波转矩和轨道激励,得到恒功率牵引工况下齿轮传动系统的动态载荷。建立齿轮箱箱体的有限元模型,利用直接积分法分析动态载荷作用下箱体的动态响应,并针对相关频率进行谐响应分析。结果表明,考虑轮齿啮合才能得到齿轮传动系统的高频振动,箱体结构能够满足正常的运营需求,异步电动机谐波转矩频率和齿轮啮合频率在箱体动态响应的主频中都有体现,在箱体结构设计时,应注意箱体自身模态频率与外界频率的错开,以免发生共振。%In order to study the dynamic characteristics of gearbox housing in high-speed train, the internal and external dynamic excitations of gear transmission system in high-speed train are calculated by numerical simulation at first, and a multi-body dynamics model of motor car including the driving system subjected to internal and external excitation is established. In this model, the internal excitations include the time-varying stiffness, damping and transmission error, the external excitations include the harmonic torque of asynchronous motor and rail irregularity, then the dynamic forces generated in the gear mesh are calculated when the train running with constant power. What is more, the dynamic forces of housing bearing seats are obtained and loaded to the finite element model of gearbox housing, the dynamic response of housing is carried out using a direct integrate method and harmonic response analysis are also finished. The results show that the high frequency vibration of the gear transmission system can only be acquired when the gear

  6. Analysis of Air Flow Field in Air Conditioning System and Compartments of High-Speed Trains%高速列车空调系统及车内流场分析

    Institute of Scientific and Technical Information of China (English)

    刘杰; 李人宪; 陈琳; 李树典

    2012-01-01

    In order to test the rationality of the air-conditioning system design of high-speed trains, an entire geometry model for compartment and air-conditioning system of high-speed trains was built considering the characteristics of negative pressure at fresh-air inlet, complicated air-conditioning pipes and good airtightness. The airflow field in the entire geometry was simulated by solving the governing differential functions of computational fluid dynamics ( CFD) using the finite volume method. The distributions of velocity field, temperature field, humidity field, and CO2 concentration in the chamber were obtained, and the thermal comfort was evaluated by flow field indexes and comfort indexes. The results show that when a train is running at 350 km/h in summer, the temperature distribution is uniform in compartments; the average value of CO2 concentration is 0.07% to meet the demand for comfort (less than 0. 15% ); because of the high wind velocity, effective temperature difference at aisle is -4. 5 °C , which is 2. 8 °C below the standard value of the thermal comfort index; and an appropriate air supply and recycle mode is crucial to obtain uniform flow field and good thermal comfort.%为检验高速列车空调系统设计的合理性,针对高速列车新风入口负压大、空调管路系统复杂、密封性好的特点,建立了车厢内部与空调系统的整体模型.用有限体积法求解计算流体力学的控制微分方程,对整体流场进行数值模拟,得到了风速、温度、湿度和CO2体积浓度在客室内的分布,并用流场指标和热舒适性指标对客室内的热舒适性进行了评价.结果表明:夏季列车以350 km/h的速度行驶时,车厢内温度场分布比较均匀,CO2体积浓度平均值为0.07%,满足不大于0.15%的舒适性要求;过道处风速高,导致有效温度差最大为-4.5℃,低于舒适指标标准值2.8℃;送、回风方式是保证流场参数均匀分布及热舒适性的关键.

  7. Initial performance of the High Speed Photometer

    Science.gov (United States)

    Richards, Evan; Percival, Jeff; Nelson, Matt; Hatter, ED; Fitch, John; White, Rick

    1991-01-01

    The Hubble Space Telescope High Speed Photometer has four image dissector tubes, two with UV sensitive photocathodes, two sensitive to the near UV and to visual light, and a single red sensitive photomultiplier tube. The HSP is capable of photometric measurements from 1200 to 7500 A with time resolution of 11 microseconds and has no moving parts. An initial analysis of the on-orbit engineering performance of the HSP is presented with changes in operating procedures resulting from the primary mirror spherical aberration and experience gained during the verification period.

  8. High Speed Solid State Circuit Breaker

    Science.gov (United States)

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  9. Accident Safety Design for High Speed Elevator

    Directory of Open Access Journals (Sweden)

    Tawiwat Veeraklaew

    2012-12-01

    Full Text Available There have been many elevators exist in buildings for such a long time; however, an accident might happen as a free fall due to lacks of maintenance or some other accident such as firing. Although this situation is rarely occurred, many people are still concerned about it. The question here is how to make passengers to feel safe and confident when they are using an elevator, especially, high speed elevator. This problem is studied here in this paper as a free fall spring-mass-damper system with the stiffness and damping coefficient can be computed as minimum jerk of the system with given constraints on trajectories.

  10. The Effect of Two Speed Endurance Training Regimes on Performance of Soccer Players.

    Directory of Open Access Journals (Sweden)

    F Marcello Iaia

    Full Text Available In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6 or speed endurance maintenance (SEM; n = 7 training, three times per wk. SEP training consisted of 6-8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6-8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (p<0.01 the total time in a repeated sprint ability test (RSAt by 2.5%. SEM training improved the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, p<0.01 and had a likely beneficial impact on the percentage decrement score of the RSA test (from 4.07±1.28 to 3.55±1.01% but induced a very likely impairment in RSAt (from 83.81±2.37 to 84.65±2.27 s. The distance covered in the Yo-Yo Intermittent Recovery test level 2 was 10.1% (p<0.001 and 3.8% (p<0.05 higher after SEP and SEM training, respectively, with possibly greater improvements following SEP compared to SEM. No differences were observed in the 20- and 40-m sprint performances. In conclusion, these two training strategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles' ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in

  11. Research on new anti-wind facility of high-speed train in strong wind area%大风区高速铁路新型防风设施研究

    Institute of Scientific and Technical Information of China (English)

    李鲲

    2012-01-01

    兰新(甘肃兰州-新疆乌鲁木齐)第二双线是世界上1条已建成的最长高速铁路,也是世界首条穿越大风区的高速铁路,线路穿越大风区最大瞬时风速达64 m/s,严重威胁列车运行安全,针对既有防风设施(主要为挡风墙)难以满足大风条件下防止列车倾覆、保护受电弓和接触网安全及防沙等要求,提出一种新型防风设施即防风走廊,并通过数值计算、风洞试验、动模型试验等方法进行系统研究.研究结果表明:在防风走廊的防护下,动车组的倾覆力矩是无防风设施时的1%~2%,是有挡风墙时的4%左右;接触网处的风速度仅为环境风速的6%左右;半封闭防风走廊开口处的最大速度仅为6.08 m/s;而走廊内部和动车组表面的压力变化表明半封闭走廊更具优势,不会附带产生隧道空气动力效应等不利影响.这说明防风走廊既能实现对列车和接触网综合防护,兼具防沙功能,同时也不会产生隧道空气动力效应等不利影响,作为一种新型高等级铁路防风设施具有应用推广价值.%The second double line of Lanzhou-Xinjiang railway is not only the longest high-speed railway line in the world but also the first one crossing strong wind area, where the highest instantaneous wind speed across strong wind area is 60 m/s, which is a serious threat to train running safety, considering the existing anti-wind facility (mainly wind break wall) is difficult to meet the demands of train overturning prevention, pantograph-catenary system protection and sand prevention, a new anti-wind facility called anti-wind corridor through numerical simulation, wind tunnel test and dynamic model test was proposed and researched. The results show that electric multiple unit(EMU)'s overturning momentum with the protection of anti-wind corridor is \\%~2% of that without the protection of wind break wall, and account for 4% when it is with the protection of wind break wall. The

  12. 76 FR 18298 - Notice of Availability of a Final Environmental Impact Statement for the DesertXpress High-Speed...

    Science.gov (United States)

    2011-04-01

    ... Considering Environmental Impacts (64 FR 28545, May 26, 1999). The Bureau of Land Management (BLM), Surface... DesertXpress High-Speed Passenger Train Project AGENCY: Federal Railroad Administration (FRA), United... High-Speed Passenger Train Project (DesertXpress project). FRA is the Lead Agency for the...

  13. Operational Modal Analysis of Bogie Frame and Its Effect on Vibration Transfer of High-speed Train%转向架构架工作模态及其对车下振动传递影响初探

    Institute of Scientific and Technical Information of China (English)

    刘佳; 赵悦; 凌亮; 圣小珍

    2015-01-01

    In order to learn the dynamic characteristics of the bogie frames of high-speed trains in traveling status, an operational modal test of the bogie was carried out. The cross spectra between the response points of the bogie frame were obtained and the modal parameters were identified by using the Least Square Complex-Frequency Method. According to the results of the identification, the pseudo modals corresponding to the obvious vibration peaks in the acceleration of the bogie induced by the excitation of the axle box were removed so that the true modal parameters were obtained. According to the measured frequency spectrum of the axle box and floor vibration, sources of the floor vibration peak frequencies were found, and the effect of the bogie frame’s operational modes on the prominent peaks was analyzed. The measured data is very useful for understanding the dynamic characteristics of the train bogie frames in operation status and the mechanism of obvious peaks of the carriage’s floor vibration. The methods of the test and modal parameter identification may provide a reference for part’s operational modal test of high-speed trains.%为进一步了解运行过程中转向架构架的真实动态特性,对实际线路运行的某高速列车进行工作模态测试,获取构架响应点之间的互谱信号并进行模态参数识别。模态参数识别方法采用最小二乘复频域法。根据其识别结果,剔除由轴箱传至构架且引起构架显著峰值的虚假模态,获得构架真实工作模态参数。结合轴箱、车体外地板振动实测频谱,找到车体外地板显著振动频率来源,进而分析转向架工作模态对车体外地板振动显著峰值的影响。本文的相关实测结果为了解运行过程中转向架构架真实动力学行为、研究车体外地板振动显著频率的产生、传递机理提供依据;同时,测试及模态参数识别方法为车体运行部件工作模态试验提供参考。

  14. High Speed Telescopic Imaging of Sprites

    Science.gov (United States)

    McHarg, M. G.; Stenbaek-Nielsen, H. C.; Kanmae, T.; Haaland, R. K.

    2010-12-01

    A total of 21 sprite events were recorded at Langmuir Laboratory, New Mexico, during the nights of 14 and 15 July 2010 with a 500 mm focal length Takahashi Sky 90 telescope. The camera used was a Phantom 7.3 with a VideoScope image intensifier. The images were 512x256 pixels for a field of view of 1.3x0.6 degrees. The data were recorded at 16,000 frames per second (62 μs between images) and an integration time of 20 μs per image. Co-aligned with the telescope was a second similar high-speed camera, but with an 85 mm Nikon lens; this camera recorded at 10,000 frames per second with 100 μs exposure. The image format was also 512x256 pixels for a field of view of 7.3x3.7 degrees. The 21 events recorded include all basic sprite elements: Elve, sprite halos, C-sprites, carrot sprites, and large jellyfish sprites. We compare and contrast the spatial details seen in the different types of sprites, including streamer head size and the number of streamers subsequent to streamer head splitting. Telescopic high speed image of streamer tip splitting in sprites recorded at 07:06:09 UT on 15 July 2010.

  15. Aerodynamic noise numerical simulation and noise reduction of high-speed train bogie section%高速列车转向架部位气动噪声数值模拟及降噪研究

    Institute of Scientific and Technical Information of China (English)

    黄莎; 杨明智; 李志伟; 徐刚

    2011-01-01

    In order to decrease the aerodynamic noise of train bogie section, three-dimensional, large eddy simulation and FW-H acoustic model were adopted to simulate the aerodynamic noise outside high-speed train bogie section based on Lighthill acoustic theory, and noise reduction advice was proposed. The results show that the aerodynamic noise is a kind of wide frequency noise which exits in wide frequency band without obvious main frequency. The acoustic pressure amplitude of every test point is great at low frequency, decreasing with the increase of frequency, and the acoustic pressure level within 1/3 octave band frequency ranges from 315 Hz to 1 250 Hz. Given a certain incoming wind speed, the total acoustic pressure level is lower when the test point is farther from the noise source. Once aprons are set in bogie sections, acoustic pressure amplitude and total acoustic pressure level of each point reduce compared with that without apron, respectively with an average reduction of about 8% and 1.3 dBA at the speed of 300 km/h. Besides, the average reduction will come to 12% and 2.08 dBA when the apron area increases properly, making noise reduction more effective apparently.%基于Lighthill声学理论,采用三维、LES大涡模拟和FW-H声学模型对高速列车转向架部位气动噪声进行数值模拟,并提出降噪改进意见.研究结果表明:转向架部位气动噪声在很宽的频带内存在,无明显的主频率,是一种宽频噪声;各监测点气动噪声频谱在低频时幅值较大,随着频率的升高,幅值下降,1/3倍频程A声压级主要集中在315~1 250 Hz频率范围内;当来流速度一定时,距离气动噪声源越远,声压级幅值和总声压级越小;在列车转向架部位设置裙板后,运行速度为300 km/h时,车外声压级幅值较无裙板时有所减小,平均降幅约为8%,总声压级平均降幅1.3 dBA;适当增加裙板面积后,声压级幅值平均降幅达到12%,总声压级平均降幅2.08dBA,降噪效果较明显.

  16. High-Speed RaPToRS

    Science.gov (United States)

    Henchen, Robert; Esham, Benjamin; Becker, William; Pogozelski, Edward; Padalino, Stephen; Sangster, Thomas; Glebov, Vladimir

    2008-11-01

    The High-Speed Rapid Pneumatic Transport of Radioactive Samples (HS-RaPToRS) system, designed to quickly and safely move radioactive materials, was assembled and tested at the Mercury facility of the Naval Research Laboratory (NRL) in Washington D.C. A sample, which is placed inside a four-inch-diameter carrier, is activated before being transported through a PVC tube via airflow. The carrier travels from the reaction chamber to the end station where it pneumatically brakes prior to the gate. A magnetic latch releases the gate when the carrier arrives and comes to rest. The airflow, optical carrier-monitoring devices, and end gate are controlled manually or automatically with LabView software. The installation and testing of the RaPToRS system at NRL was successfully completed with transport times of less than 3 seconds. The speed of the carrier averaged 16 m/s. Prospective facilities for similar systems include the Laboratory for Laser Energetics and the National Ignition Facility.

  17. High-speed ACR/NEMA interface

    Science.gov (United States)

    Reijns, Gerard L.; Santilli, D.; Schellingerhout, G.; Jochem, A. J.; Ottes, Fenno P.; van Aken, I. W.

    1990-08-01

    The design and implementation of a standard high speed ACR-NEMA communications interface is described. The upper layers e.g. the Presentation layer, Session layer and part of the Transport/Network layer have been implemented in software. In order to reach the speed requirement of 8M byte/sec. the lower layers e.g. part of the Transport/Network layer and Data Link layer have been implemented in hardware. We have developed and built an interface for an IBM personal computer P5/2 model 50, working under the operating system OS/2. The PS/2, model 50 has been equipped with a fast micro-channel bus, which enables a large throughput. The operating systern OS/2 has a multitasking capability, which enables concurrent programming. In order to minimize the delays, we used this multitasking facility to create a number of parallel operating "threads". The Transport/Network layer functions have been implemented using a receive thread, two send threads and a device driver with three hardware registers. The time to transfer a packet by DMA, to initiate the DMA logic and to execute the required Kernal functions have each been measured and figures are shown. The Data Link layer provides for storage of two packets in two separate random access memories (RAM's). These two RAM's enable a pipelined operation, which minimizes the delay in the Data Link layer.

  18. High Speed Fibre Optic Backbone LAN

    Science.gov (United States)

    Tanimoto, Masaaki; Hara, Shingo; Kajita, Yuji; Kashu, Fumitoshi; Ikeuchi, Masaru; Hagihara, Satoshi; Tsuzuki, Shinji

    1987-09-01

    Our firm has developed the SUMINET-4100 series, a fibre optic local area network (LAN), to serve the communications system trunk line needs for facilities, such as steel refineries, automobile plants and university campuses, that require large transmission capacity, and for the backbone networks used in intelligent building systems. The SUMINET-4100 series is already in service in various fields of application. Of the networks available in this series, the SUMINET-4150 has a trunk line speed of 128 Mbps and the multiplexer used for time division multiplexing (TDM) was enabled by designing an ECL-TTL gate array (3000 gates) based custom LSI. The synchronous, full-duplex V.24 and V.3.5 interfaces (SUMINET-2100) are provided for use with general purpose lines. And the IBM token ring network, the SUMINET-3200, designed for heterogeneous PCs and the Ethernet can all be connected to sub loops. Further, the IBM 3270 TCA and 5080 CADAM can be connected in the local mode. Interfaces are also provided for the NTT high-speed digital service, the digital PBX systems, and the Video CODEC system. The built-in loop monitor (LM) and network supervisory processor (NSP) provide management of loop utilization and send loop status signals to the host CPU's network configuration and control facility (NCCF). These built-in functions allow both the computer system and LAN to be managed from a single source at the host. This paper outlines features of the SUMINET-4150 and provides an example of its installation.

  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. 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...

  1. 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…

  2. 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…

  3. HIGH SPEED INJECTION MOLDING OF HIGH DENSITY POLYETHYLENE - EFFECTS OF INJECTION SPEED ON STRUCTURE AND PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Kun Jiang; Feng Chen; Qiang Fu; Fei-long Yu; Run Su; Jing-hui Yang; Tian-nan Zhou; Jian Gao; Hua Deng; Ke Wang; Qin Zhang

    2011-01-01

    Thin wall samples of high density polyethylene (HDPE) were prepared via injection molding with differentinjection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young's moduluswas observed with increasing injection speed. In order to investigate the mechanism behind this decrease, the orientation,molecular weight, molecular weight distribution, melt flow rate, crystallinity and crystal morphology of HDPE werecharacterized using two-dimensional wide-angle X-ray diffraction (2D-WAXD), gel permeation chromatography (GPC),capillary rheometry and differential scanning calorimetry (DSC), respectively. It is demonstrated that the orientation,molecular weight, molecular weight distribution, melt flow rate and crystallinity have no obvious change with increasinginjection speed. Nevertheless, the content of extended chain crystals or large folded chain crystals was found to decreasewith increasing injection speed. Therefore, it is concluded that the decrease in tensile properties is mainly contributed by the reduced content of extended chain crystals or large folded chain crystals. This study provides industry with valuableinformation for the application of high speed injection molding.

  4. Design of A Novel High Speed Dynamic Comparator with Low Power Dissipation for High Speed ADCs

    Directory of Open Access Journals (Sweden)

    Sougata Ghosh

    2013-01-01

    Full Text Available A new CMOS dynamic comparator using dual input single output differential amplifier as latch stage suitable for high speed analog-to-digital converters with High Speed, low power dissipation and immune to noise than the previous reported work is proposed. Back to-back inverter in the latch stage is replaced with dual-input single output differential amplifier. This topology completely removes the noise that is present in the input. The structure shows lower power dissipation and higher speed than the conventional comparators. The circuit is simulated with 1V DC supply voltage and 250 MHz clock frequency. The proposed topology is based on two cross coupled differential pairs positive feedback and switchable current sources, has a lower power dissipation, higher speed, less area, and it is shown to be very robust against transistor mismatch, noise immunity. Previous reported comparators are designed and simulated their DC response and Transient response in Cadence®Virtuoso Analog Design Environment using GPDK 90nm technology. Layouts of the proposed comparator have been done in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS has been checked and compared with the corresponding circuits and RC extracted diagram has been generated. After that post layout simulation with 1V supply voltage has been done and compared the speed, power dissipation, Area, delay with the results before layout and the superior features of the proposed comparator are established

  5. 76 FR 71353 - Notice of Availability of the Record of Decision for the DesertXpress Enterprises, LLC High-Speed...

    Science.gov (United States)

    2011-11-17

    ... Enterprises, LLC High-Speed Passenger Train Project AGENCY: Bureau of Land Management, Interior. ACTION... Record of Decision (ROD) for the DesertXpress Enterprises, LLC High-Speed Passenger Train Project (Desert...-managed lands to build an Electrical Multiple Unit (EMU) high-speed passenger rail line in compliance...

  6. A High Speed Autofocusing System for Micro System Applications

    Institute of Scientific and Technical Information of China (English)

    Phuchong Sripolsaen; Pradit Mittrapiyanuruk; Pakorn Keawtrakulpong

    2016-01-01

    In this paper, we present a high speed autofocus system for micro system applications and design a look-up-table based autofocusing algorithm for applications when a target object is always visible, e.g., manufacturing parts with alignment fiducials. We perform an evaluation of 24 focus measures to verify that which focus measure is the best for the look-up-table based method. From the evaluation, we find that the Chebyshev moments-based focus measure (CHEB) is the most suitable. Furthermore, we also develop a look-up-table based autofocus system that uses CHEB as the focus measure. In training phase, we offline construct a table from training images of an object that are captured at several lens distances. Each entry of table consists of focus measure computed from image and lens distance. In working phase, given an input image, the algorithm first computes the focus measure and then finds the best match focus measure from the table and looks up the corresponding lens position for moving it into the in-focus position. Our algorithm can perform autofocusing within only 2 steps of lens moving. The experiment shows that the system can perform high speed autofocusing of micro objects.

  7. The effect of two speed endurance training regimes on performance of soccer players

    DEFF Research Database (Denmark)

    Iaia, F Marcello; Fiorenza, Matteo; Perri, Enrico

    2015-01-01

    -8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6-8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (prepeated sprint ability test (RSAt) by 2.5%. SEM training improved...... different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles' ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short...... the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, p

  8. Neutron and high speed photogrammetric arcjet diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, P.A.E.; Rogers, J.D.; Fowler, P.H.; Deininger, W.D.; Taylor, A.D.

    1989-01-01

    Two methods for real time internal diagnostics of arcjet engines are described. One method uses cold, thermal, or epithermal neutrons. Cold neutrons are used to detect the presence and location of hydrogenous propellants. Thermal neutrons are used to delineate the edge contours of anode and cathode surfaces and to measure stress/strain. Epithermal neutrons are used to measure temperatures on arcjet surfaces, bulk material temperatures, and point temperatures in bulk materials. It is found that this method, with an exposure time of 10 min, produces at temperature accuracy for W or Re of + or - 2.5 C. The other method uses visible-light high-speed photogrammetry to obtain images of the transient behavior of the arc during start-up and to relate this behavior to electrial supply characteristics such as voltage, current, and ripple.

  9. Merging of high speed argon plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Case, A.; Messer, S.; Brockington, S.; Wu, L.; Witherspoon, F. D. [HyperV Technologies Corp., Chantilly, Virginia 22180 (United States); Elton, R. [University of Maryland, College Park, Maryland 20742 (United States)

    2013-01-15

    Formation of an imploding plasma liner for the plasma liner experiment (PLX) requires individual plasma jets to merge into a quasi-spherical shell of plasma converging on the origin. Understanding dynamics of the merging process requires knowledge of the plasma phenomena involved. We present results from the study of the merging of three plasma jets in three dimensional geometry. The experiments were performed using HyperV Technologies Corp. 1 cm Minirailguns with a preionized argon plasma armature. The vacuum chamber partially reproduces the port geometry of the PLX chamber. Diagnostics include fast imaging, spectroscopy, interferometry, fast pressure probes, B-dot probes, and high speed spatially resolved photodiodes, permitting measurements of plasma density, temperature, velocity, stagnation pressure, magnetic field, and density gradients. These experimental results are compared with simulation results from the LSP 3D hybrid PIC code.

  10. 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)

  11. 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

  12. Photodetector having high speed and sensitivity

    Science.gov (United States)

    Morse, Jeffrey D.; Mariella, Jr., Raymond P.

    1991-01-01

    The present invention provides a photodetector having an advantageous combination of sensitivity and speed; it has a high sensitivity while retaining high speed. In a preferred embodiment, visible light is detected, but in some embodiments, x-rays can be detected, and in other embodiments infrared can be detected. The present invention comprises a photodetector having an active layer, and a recombination layer. The active layer has a surface exposed to light to be detected, and comprises a semiconductor, having a bandgap graded so that carriers formed due to interaction of the active layer with the incident radiation tend to be swept away from the exposed surface. The graded semiconductor material in the active layer preferably comprises Al.sub.1-x Ga.sub.x As. An additional sub-layer of graded In.sub.1-y Ga.sub.y As may be included between the Al.sub.1-x Ga.sub.x As layer and the recombination layer. The recombination layer comprises a semiconductor material having a short recombination time such as a defective GaAs layer grown in a low temperature process. The recombination layer is positioned adjacent to the active layer so that carriers from the active layer tend to be swept into the recombination layer. In an embodiment, the photodetector may comprise one or more additional layers stacked below the active and recombination layers. These additional layers may include another active layer and another recombination layer to absorb radiation not absorbed while passing through the first layers. A photodetector having a stacked configuration may have enhanced sensitivity and responsiveness at selected wavelengths such as infrared.

  13. 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.

  14. 风雨联合作用下高速列车受力数值模拟%Simulation of the action effect of wind-driven rain on high-speed train

    Institute of Scientific and Technical Information of China (English)

    敬俊娥; 高广军

    2013-01-01

    k-ε double equation turbulent model and discrete phase model were used in the research of the effect of different rainfall intensities,different wind speeds and different train velocityies on the flow field around the vehicle.The results show that the rain drops under the effect of cross wind crash on to the surface of the carriage and then splash,which change the roughness and smoothness of the surface of the carriage,So it leads to that the side force,lift force and capsizing moment increase gradually with the increase of wind speed,train speed and rainfall intensity.The dynamic load on train when bearing strong wind and rainfall is a little bigger than that when bearing only strong wind load.%采用双方程湍流模型和离散相模型相结合的方法,对不同降雨强度、横风风速和车速下高速运动车辆周围的流场进行研究.研究结果表明:在横风作用下,下落的雨滴与高速运行的列车发生碰撞,雨滴飞溅、改变了车身表面的粗糙度和不平整性,导致车辆运行横向力、升力和倾覆力矩均随着车速、风速和降雨强度的增大逐渐变大;伴随着降雨过程的强横风作用,车辆所受的气动载荷与强横风的单独作用情况下相比稍微增加.

  15. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating

    Directory of Open Access Journals (Sweden)

    Carolin Stangier, Thomas Abel, Julia Mierau, Wildor Hollmann, Heiko K. Strüder

    2016-03-01

    Full Text Available The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour for 8 weeks. Training intensity was determined within non-specific (cycling or running and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m and one non-specific (30s cycling or 200m running all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa and glucose (BGL 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak was significantly increased (+17%; p = 0.01 in both groups and highly correlated with the sprint performance (r = -0.71. BLa values decreased significantly (-18%, p = 0.02 after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04 in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group.

  16. 高速列车弹性车体与转向架耦合振动分析%Coupled vibration analysis of flexible car body and bogie for high-speed train

    Institute of Scientific and Technical Information of China (English)

    宫岛; 周劲松; 孙文静; 谢维达

    2011-01-01

    A finite element model of car body for a high-speed train was built,and the modal parameters were calculated by using Guyan reduction method.A system dynamics model including flexible car body was established by using multi-body dynamics software SIMPACK.The influence of car body elastic mode on riding quality was analyzed based on the model,and the vertical coupled vibration between flexible car body and bogie frame was studied.Analysis result shows that when the first vertical bending frequency of car body closes to the null nod response frequency of car body,the vertical flexible resonance of car body will happen.When the diagonal distortion frequency is higher than 9 Hz,and first vertical bending frequency is higher than 10 Hz,car body flexibility almost has no effect on riding quality.The primary suspension vertical stiffness of bogie for the train matches with the first vertical bending frequency of car body,even if frame bounce and nod frequencies coincide with the first vertical bending frequency,there will not have the flexible resonance of car body and bogie.1 tab,9 figs,15 refs.%建立了某高速列车车体有限元模型,采用Guyan缩减进行模态求解,结合SIMPACK多体动力学软件建立包含弹性车体的系统动力学模型。运用模型分析了车体弹性模态对运行平稳性的影响,研究了弹性车体与转向架构架垂向耦合振动。分析结果表明:当车体垂向一阶弯曲频率与车体点头振动空响应点频率接近时,会发生车体的垂向弹性共振;当车体菱形变形弯曲频率高于9 Hz,垂向一阶弯曲频率高于10 Hz时,车体弹性对运行平稳性影响不大;该高速列车转向架一系悬挂垂向刚度与车体垂向一阶弯曲频率匹配合适,即使构架浮沉及点头频率与车体垂向一

  17. VLSI circuits for high speed data conversion

    Science.gov (United States)

    Wooley, Bruce A.

    1994-05-01

    The focus of research has been the study of fundamental issues in the design and testing of data conversion interfaces for high performance VLSI signal processing and communications systems. Because of the increased speed and density that accompany the continuing scaling of VLSI technologies, digital means of processing, communicating, and storing information are rapidly displacing their analog counterparts across a broadening spectrum of applications. In such systems, the limitations on system performance generally occur at the interfaces between the digital representation of information and the analog environment in which the system is embedded. Specific results of this research include the design and implementation of low-power BiCMOS comparators and sample-and-hold amplifiers operating at clock rates as high as 200 MHz, the design and integration of a 12-bit, 5 MHz CMOS A/D converter employing a two-step architecture and a novel self-calibrating comparator, the design and integration of an optoelectronic communications receiver front-end in a GaAs-on-Si technology, the initiation of research into the use of an active silicon substrate probe card for fully testing high-performance mixed-signal circuits at the wafer level, and a preliminary study of means for correcting dynamic errors in high-performance A/D converters.

  18. High-Speed Smart Camera with High Resolution

    Directory of Open Access Journals (Sweden)

    J. Dubois

    2007-02-01

    Full Text Available High-speed video cameras are powerful tools for investigating for instance the biomechanics analysis or the movements of mechanical parts in manufacturing processes. In the past years, the use of CMOS sensors instead of CCDs has enabled the development of high-speed video cameras offering digital outputs, readout flexibility, and lower manufacturing costs. In this paper, we propose a high-speed smart camera based on a CMOS sensor with embedded processing. Two types of algorithms have been implemented. A compression algorithm, specific to high-speed imaging constraints, has been implemented. This implementation allows to reduce the large data flow (6.55 Gbps and to propose a transfer on a serial output link (USB 2.0. The second type of algorithm is dedicated to feature extraction such as edge detection, markers extraction, or image analysis, wavelet analysis, and object tracking. These image processing algorithms have been implemented into an FPGA embedded inside the camera. These implementations are low-cost in terms of hardware resources. This FPGA technology allows us to process in real time 500 images per second with a 1280×1024 resolution. This camera system is a reconfigurable platform, other image processing algorithms can be implemented.

  19. High-Speed Smart Camera with High Resolution

    Directory of Open Access Journals (Sweden)

    Mosqueron R

    2007-01-01

    Full Text Available High-speed video cameras are powerful tools for investigating for instance the biomechanics analysis or the movements of mechanical parts in manufacturing processes. In the past years, the use of CMOS sensors instead of CCDs has enabled the development of high-speed video cameras offering digital outputs, readout flexibility, and lower manufacturing costs. In this paper, we propose a high-speed smart camera based on a CMOS sensor with embedded processing. Two types of algorithms have been implemented. A compression algorithm, specific to high-speed imaging constraints, has been implemented. This implementation allows to reduce the large data flow (6.55 Gbps and to propose a transfer on a serial output link (USB 2.0. The second type of algorithm is dedicated to feature extraction such as edge detection, markers extraction, or image analysis, wavelet analysis, and object tracking. These image processing algorithms have been implemented into an FPGA embedded inside the camera. These implementations are low-cost in terms of hardware resources. This FPGA technology allows us to process in real time 500 images per second with a 1280×1024 resolution. This camera system is a reconfigurable platform, other image processing algorithms can be implemented.

  20. High-temperature MAS-NMR at high spinning speeds.

    Science.gov (United States)

    Kirchhain, Holger; Holzinger, Julian; Mainka, Adrian; Spörhase, Andreas; Venkatachalam, Sabarinathan; Wixforth, Achim; van Wüllen, Leo

    2016-09-01

    A low cost version to enable high temperature MAS NMR experiments at temperatures of up to 700°C and spinning speeds of up to 10kHz is presented. The method relies on inductive heating using a metal coated rotor insert. The metal coating is accomplished via a two step process involving physical vapor deposition and galvanization.

  1. THE EFFECTS OF SPECIFIC TRAINING ON THE FORMS OF SPEED MANIFESTATION IN JUDO

    Directory of Open Access Journals (Sweden)

    Galea Ioan

    2015-10-01

    Full Text Available The purpose of the study was to investigate the influences specific speed training on the forms of its manifestation in judo. Methods: The subjects of the survey were two 10-student groups practicing judo at C.S.S. Gloria of Arad – a control group (C.Gr.: M age = 11.5 ±1.35, M weight = 41.7 kg ±7.85kg, and an experimental group (E.Gr.: M age = 11.7 ±0.82, M weight = 48.8 kg ±7.90kg. There was an initial testing (I.T. for the two groups with the OptoJump device (MicroGate, 2005 for 3 forms of speed: reaction rate (R.R., running speed (R.S. and motion speed (M.S.. The following 14 training sessions included, for the E.Gr., 13-15 min. speed development exercises; the C.Gr. performed their usual training. The final testing (F.T. was similar for the two groups. Results: The subjects who completed a specific speed training (E.Gr. showed an improvement of the forms of expression of speed compared to those who did not participate in the program (C.Gr.. Conclusions: Conducting a specific training program to develop manifestations of speed at the age of 11-12 is a solution for optimizing the training of young judoka.

  2. Material constraints on high-speed design

    Science.gov (United States)

    Bucur, Diana; Militaru, Nicolae

    2015-02-01

    Current high-speed circuit designs with signal rates up to 100Gbps and above are implying constraints for dielectric and conductive materials and their dependence of frequency, for component elements and for production processes. The purpose of this paper is to highlight through various simulation results the frequency dependence of specific parameters like insertion and return loss, eye diagrams, group delay that are part of signal integrity analyses type. In low-power environment designs become more complex as the operation frequency increases. The need for new materials with spatial uniformity for dielectric constant is a need for higher data rates circuits. The fiber weave effect (FWE) will be analyzed through the eye diagram results for various dielectric materials in a differential signaling scheme given the fact that the FWE is a phenomenon that affects randomly the performance of the circuit on balanced/differential transmission lines which are typically characterized through the above mentioned approaches. Crosstalk between traces is also of concern due to propagated signals that have tight rise and fall times or due to high density of the boards. Criteria should be considered to achieve maximum performance of the designed system requiring critical electronic properties.

  3. Effects of Cycling vs. Running Training on Endurance Performance in Preparation for Inline Speed Skating.

    Science.gov (United States)

    Stangier, Carolin; Abel, Thomas; Hesse, Clemens; Claen, Stephanie; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-06-01

    Winter weather conditions restrict regular sport-specific endurance training in inline speed skating. As a result, this study was designed to compare the effects of cycling and running training programs on inline speed skaters' endurance performance. Sixteen (8 men, 8 women) high-level athletes (mean ± SD 24 ± 8 years) were randomly assigned to 1 of 2 groups (running and cycling). Both groups trained twice a week for 8 weeks, one group on a treadmill and the other on a cycle ergometer. Training intensity and duration was individually calculated (maximal fat oxidation: ∼52% of V[Combining Dot Above]O2peak: 500 kcal per session). Before and after the training intervention, all athletes performed an incremental specific (inline speed skating) and 1 nonspecific (cycling or running) step test according to the group affiliation. In addition to blood lactate concentration, oxygen uptake (V[Combining Dot Above]O2), ventilatory equivalent (VE/V[Combining Dot Above]O2), respiratory exchange ratio (RER), and heart rate were measured. The specific posttest revealed significantly increased absolute V[Combining Dot Above]O2peak values (2.9 ± 0.4, 3.4 ± 0.7, p = 0.01) and submaximal V[Combining Dot Above]O2 values (p ≤ 0.01). VE/V[Combining Dot Above]O2 and RER significantly decreased at maximal (46.6 ± 6.6, 38.5 ± 3.4, p = 0.005; 1.1 ± 0.03, 1.0 ± 0.04, p = 0.001) and submaximal intensities (p ≤ 0.04). None of the analysis revealed a significant group effect (p ≥ 0.15). The results indicate that both cycling vs. running exercise at ∼52% of V[Combining Dot Above]O2peak had a positive effect on the athletes' endurance performance. The increased submaximal V[Combining Dot Above]O2 values indicate a reduction in athletes' inline speed skating technique. Therefore, athletes would benefit from a focus on technique training in the subsequent period.

  4. 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.

  5. Differential Effects of Reasoning and Speed Training in Children

    Science.gov (United States)

    Mackey, Allyson P.; Hill, Susanna S.; Stone, Susan I.; Bunge, Silvia A.

    2011-01-01

    The goal of this study was to determine whether intensive training can ameliorate cognitive skills in children. Children aged 7 to 9 from low socioeconomic backgrounds participated in one of two cognitive training programs for 60 minutes/day and 2 days/week, for a total of 8 weeks. Both training programs consisted of commercially available…

  6. High Speed, Low Weight Momentum/Reaction Wheels

    OpenAIRE

    1999-01-01

    Advancements in several critical areas have made possible lightweight, strong and highly reliable momentum / reaction wheels. The development of reliable bearings with design features that allow high speed operation for space flight applications has significantly altered the weight / speed / wheel design considerations. Current designs typically operate at speeds at or below 6,000 RPM The new retainerless can achieve speeds 10 times that and meet or improve all other significant bearing opera...

  7. 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

  8. Modeling of high-speed electronic devices

    Directory of Open Access Journals (Sweden)

    V. G. Kudrya

    2013-09-01

    Full Text Available Introduction. The theme of this publication is the modeling of electronic tools that operate in the frequency range from zero to terahertz and higher. Application of new concepts and technologies, including biotechnology and nanotechnology in the development of monolithic integrated circuits led to a backlog of technologies of projecting from technologies and experimental research and manufacturing. The aim of this work is to develop algorithms for analysis, reflecting not only topological as well as morphological properties of the object, that is designing within the framework of accounting EMI communicational  transmission of energy and information in the volume of the monolithic integrated circuit. Basic steps for constructing the algorithm. The object of design is presented in the form of basic elements, which can be combined with a communication structure. The object of design is presented in the form of basic elements, which can be combined with a communication structure. There are three types of matrix equations: component; component - communication structure; communication structure. Systems of equations are reduced to standardized descriptors of mathematical model by which to understand current of poles and voltage arcs whole set of basic elements. In this way obtained mathematical model that can be implemented in CAD nano and micro technology electronics. Conclusions. Mathematical models of analysis of high-speed digital and analog electronic means. The algorithm allows morphological optimization is to minimize the adverse effects outside the system of electromagnetic interaction between the components and communicator.

  9. Enhanced high-speed coherent diffraction imaging

    Science.gov (United States)

    Potier, Jonathan; Fricker, Sebastien; Idir, Mourad

    2011-03-01

    Due to recent advances in X-ray microscopy, we are now able to image objects with nanometer resolution thanks to Synchrotron beam lines or Free Electron Lasers (FEL). The PCI (Phase Contrast Imaging) is a robust technique that can recover the wavefront from measurements of only few intensity pictures in the Fresnel diffraction region. With our fast straightforward calculus methods, we manage to provide the phase induced by a microscopic specimen in few seconds. We can therefore obtain high contrasted images from transparent materials at very small scales. To reach atomic resolution imaging and thus make a transition from the near to the far field, the Coherent Diffraction Imaging (CDI) technique finds its roots in the analysis of diffraction patterns to obtain the phase of the altered complex wave. Theoretical results about existence and uniqueness of this retrieved piece of information by both iterative and direct algorithms have already been released. However, performances of algorithms remain limited by the coherence of the X-ray beam, presence of random noise and the saturation threshold of the detector. We will present reconstructions of samples using an enhanced version of HIO algorithm improving the speed of convergence and its repeatability. As a first step toward a practical X-Ray CDI system, initial images for reconstructions are acquired with the laser-based CDI system working in the visible spectrum.

  10. Balancing rotor speed regulation and drive train loads of floating wind turbines

    Science.gov (United States)

    Fischer, Boris; Loepelmann, Peter

    2016-09-01

    The interaction of the blade pitch controller with structural motion is particularly important for wind turbines mounted on floating platforms. A controls-based approach to overcome the related technical challenges is to feed back the nacelle's motion to the demanded generator torque. This work aims to further improve this approach by feeding back only a narrow fraction of the available frequency range. Simulations show that, in doing so, unrealistically high torque magnitudes are avoided, and better a trade-off between rotor speed regulation and drive train loads is achieved.

  11. 高速列车波纹外地板低噪声优化设计%Low-noise optimization design of external corrugated floor for high-speed train

    Institute of Scientific and Technical Information of China (English)

    沈火明; 张玉梅; 肖新标; 金学松

    2011-01-01

    Based on the hybrid finite element and statistical energy analysis(hybrid FE-SEA) and the principle of periodic substructure, a acoustic characteristic simulation model of external corrugated floor used in high-speed train was established. According to the transmission loss of external corrugated floor structure, the sound insulation property was evaluated. Corrugated floor structure, corrugated floor structure with top plate, corrugated floor structure with bottom plate, corrugated floor structure with splint were chosen, and the sound insulation properties of the structures were analyzed under different web angles. Calculation result shows that the sound insulation losses of corrugated floor structure and corrugated floor structure with top plate are bigger than the other two structures at every angle. Corrugated floor structure with bottom plate has the worst sound insulation property, but corrugated floor structure with top plate has the best sound insulation property, and their sound insulation difference is 6.9 dB while the web angle is 55°. Through the analysis of sound insulation loss, the best combinations of external corrugated structures and web angles under different frequency noises are obtained, which can provide evidence for the low-nosie structure design of external corrugated floor for high-speed strain.%基于混合有限元一统计能量法及周期子结构原理,建立了高速列车波纹外地板声学特性仿真模型,根据波纹外地板结构的传递损失评价隔声性能,分析了波纹板结构、波纹板加上板结构、波纹板加下板结构和波纹板加夹板结构在不同腹板倾角下的隔声性能.计算结果表明:波纹板和波纹板加上板结构在各个角度的隔声量都明显高于其他两种结构;波纹板加下板结构隔声效果最差,波纹板加上板结构隔声效果最好,两者在腹板倾角为55°时隔声量差值为6.9 dB.通过隔声量分析,得出了不同频率噪声下的腹板倾

  12. High-speed image matching with coaxial holographic optical correlator

    Science.gov (United States)

    Ikeda, Kanami; Watanabe, Eriko

    2016-09-01

    A computation speed of more than 100 Gbps is experimentally demonstrated using our developed ultrahigh-speed optical correlator. To verify this high computation speed practically, the computation speeds of our optical correlator and conventional digital image matching are quantitatively compared. We use a population count function that achieves the fastest calculation speed when calculating binary matching by a central processing unit (CPU). The calculation speed of the optical correlator is dramatically faster than that using a CPU (2.40 GHz × 4) and 16 GB of random access memory, especially when the calculation data are large-scale.

  13. 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.)

  14. METHODOLOGY OF DETERMINATION OF ADMISSIBLE SPEEDS OF TRAIN MOVEMENT ON DIFFICULT SECTIONS OF RAILROAD PLAN

    Directory of Open Access Journals (Sweden)

    M. B. Kurhan

    2014-03-01

    Full Text Available Purpose. Determination of improvement ways of admissible speeds of train movement on the difficult sections of а railroad plan. Methodology. Mathematical modeling of the train traffic is used to achieve the purpose of research. The average weighted speed and elevation of outer rail is predicted on this basis. Findings. The case analysis of the speeds determination in curved sections of track was carried out. The above mentioned track sections adversely affect the ride comfort and the intensity of the way disorder, as well as the reasons that contribute to the speed limits traffic on the railways of Ukraine. The technique of performing the calculations for determining the permissible train speeds was developed and tested on real curves of railways, were the accelerated movement of trains was introduced. Proposals on automate calculations in distances and services by way of determining the permissible speeds in curves were developed. Originality. Methodology of determining the permissible motion speeds and elevation of outer rails on the difficult sections of the railway plan was developed. This approach allows you to get a rational decisions on reorganization of plan based on local conditions. Practical value. The developed technique of definition of admissible speeds of motion in curves was implemented as a program DopShvid. The program was tested on real railway sections, where the accelerated train motion was introduced.

  15. High Speed Dynamics in Brittle Materials

    Science.gov (United States)

    Hiermaier, Stefan

    2015-06-01

    Brittle Materials under High Speed and Shock loading provide a continuous challenge in experimental physics, analysis and numerical modelling, and consequently for engineering design. The dependence of damage and fracture processes on material-inherent length and time scales, the influence of defects, rate-dependent material properties and inertia effects on different scales make their understanding a true multi-scale problem. In addition, it is not uncommon that materials show a transition from ductile to brittle behavior when the loading rate is increased. A particular case is spallation, a brittle tensile failure induced by the interaction of stress waves leading to a sudden change from compressive to tensile loading states that can be invoked in various materials. This contribution highlights typical phenomena occurring when brittle materials are exposed to high loading rates in applications such as blast and impact on protective structures, or meteorite impact on geological materials. A short review on experimental methods that are used for dynamic characterization of brittle materials will be given. A close interaction of experimental analysis and numerical simulation has turned out to be very helpful in analyzing experimental results. For this purpose, adequate numerical methods are required. Cohesive zone models are one possible method for the analysis of brittle failure as long as some degree of tension is present. Their recent successful application for meso-mechanical simulations of concrete in Hopkinson-type spallation tests provides new insight into the dynamic failure process. Failure under compressive loading is a particular challenge for numerical simulations as it involves crushing of material which in turn influences stress states in other parts of a structure. On a continuum scale, it can be modeled using more or less complex plasticity models combined with failure surfaces, as will be demonstrated for ceramics. Models which take microstructural

  16. Experimental determination of the critical welding speed in high speed MAG welding

    Institute of Scientific and Technical Information of China (English)

    Hu Zhikun; Wu Chuansong

    2008-01-01

    In high speed MAG welding process, some weld formation defects may be encountered. To get good weld quality, the critical welding speed beyond which humping or undercutting weld bead can occur must be known for different conditions. In this research, high speed MAG welding tests were carried out to check out the effects of different factors on the critical welding speed. Through observing the weld bead profiles and the macrographs of the transverse sections of MAG welds, the occurrence tendency of humping weld was analyzed, and the values of critical welding speed were determined under different levels of welding current or voltage, and the effect of shielding gas compositions on the critical welding speed was also investigated.

  17. 622 Mbps High-speed satellite communication system for WINDS

    Science.gov (United States)

    Ogawa, Yasuo; Hashimoto, Yukio; Yoshimura, Naoko; Suzuki, Ryutaro; Gedney, Richard T.; Dollard, Mike

    2006-07-01

    WINDS is the experimental communications satellite currently under joint development by Japanese Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). The high-speed satellite communication system is very effective for quick deployment of high-speed networks economically. The WINDS will realize ultra high-speed networking and demonstrate operability of satellite communication systems in high-speed internet. NICT is now developing high-speed satellite communication system for WINDS. High-speed TDMA burst modem with high performance TPC error correction is underdevelopment. Up to the DAC on the transmitter and from the ADC on the receiver, all modem functions are performed in the digital processing technology. Burst modem has been designed for a user data rate up to 1244 Mbps. NICT is developing the digital terminal as a user interface and a network controller for this earth station. High compatibility with the Internet will be provided.

  18. 现代三级跳远运动员的速度训练%Speed training of modern triple jumper

    Institute of Scientific and Technical Information of China (English)

    郭元奇

    2001-01-01

    The triple jump skill has been developed a speed type from the high jump and the flat jump types. In order to suit the needs of this kind of skill, we should understand the speed training of modem triple jumper again. The speed training of modem triple jumper should include the developing running speed (the capacity of running, absolute speed, approach speed), speed strength and speed jumping.%三级跳远技术由高跳型、平跳型已经发展成速度型。为了适应这种技术,应该重新认识现代三级跳远运动员的速度训练,它包括发展运动员跑的速度(跑的能力、绝对速度、助跑速度)、速度性力量和快速跳跃能力。

  19. Agile Port and High Speed Ship Technologies

    Science.gov (United States)

    2009-12-31

    Ports" Press-Telegram. November 17, 2006. Weikel, Dan. "Ports Considering Maglev Trains to Cut Smog." Los Angeles Times. Page B2. November 28, 2006...approved Expeditionary Theater Opening (ETO) Joint Doctrine; Organizations; Training ; Materiel; Leadership and Education; Personnel; and Facilities...Alternative Shipboard Powering Systems for Naval and Regulatory Review • The Evaluation and Implementation Plan for Southern California Maglev

  20. 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

  1. 高速列车锻钢制动盘多裂纹间作用机制研究%Study on Interaction Mechanism between Cracks at Forged Steel Brake Disc for High Speed Train

    Institute of Scientific and Technical Information of China (English)

    石晓玲; 李强; 薛海; 赵方伟

    2016-01-01

    To address the multiple crack problem occurring to the forged steel brake discs of high-speed train in the practical application,the interaction mechanism between cracks was studied by combining the 1 ∶1 bench test with finite element calculation.The findings from the 1∶1 bench test on brake disc proved a certain regu-larity in crack propagation.In order to further investigate the interaction mechanism between cracks,the ther-mal stress on brake disc was calculated in the case of emergency braking three times with the speed of 200 km/h by using the finite element method.Based on the above research,the crack model of brake disk surface was established using FRANC3D software to analyze the stress intensity factor of crack front and the interaction mechanism between cracks.The results showed that the interaction between the main cracks and secondary cracks changed with the change of the number of cracks and the crack location.Different ratio between the depth and length had different effect.The more the number of the radial cracks was,the slower surface crack growth.As a result,the fatigue failure of the brake disc was effectively delayed.The analysis results were con-sistent with the interaction regularity of the brake disc from the 1∶1 bench test.%针对高速列车锻钢制动盘在实际运用中出现的多裂纹问题,通过1∶1台架试验与有限元计算相结合的方法研究了制动盘多裂纹间的作用机制。依据制动盘1∶1台架试验结果发现,盘面裂纹的扩展具有一定的规律性。为进一步研究裂纹间的作用机制,运用有限元方法计算了制动盘在3次连续200 km/h 紧急制动后的热应力。在此基础上,采用 FRANC3D 软件建立了制动盘盘面的裂纹模型,分析研究了制动盘裂纹前缘的应力强度因子及多裂纹间的作用机制。分析结果表明,主、副裂纹间的相互作用随着裂纹数量和空间位置的变化而变化,不同的深长比有不同的

  2. 基于多源信息的高速列车走行部故障识别方法%High-speed train running gear fault recognition based on information fusion of multi-source

    Institute of Scientific and Technical Information of China (English)

    朱建渠; 金炜东; 郑高; 朱斌

    2014-01-01

    针对高速列车安全性能跟踪监测点多、监测数据量大而导致的走行部故障识别难的问题,提出了一种基于模糊证据理论的多特征、多源信息融合的走行部故障识别方法。首先根据不同传感器信息的某类特征属于不同故障模式下的隶属度间的差异来计算传感器间的信息融合度,利用融合度来确定不同传感器在融合中的权重,从而得到同类特征不同传感器间信息融合后的隶属度;然后由融合后的隶属度转化为基本概率分配函数;最后用证据理论对不同特征间信息进行融合。实验结果表明,该方法能有效地识别列车正常、空气弹簧失气、抗蛇形减震器全拆、横向减震器全拆四种情况,同时在不同速度下均取得了满意的识别率,验证了该方法的有效性。%To solve the problem that it is difficult to identify faults of high-speed train running gears caused by multiple detection points and large amount of data,a running gear fault recognition method with multi-feature and multi-source information fusion was proposed based on the fuzzy evidence theory.Firstly,the information fusion levels of sensors were obtained by calculating the difference of membership degrees reflecting a certain feature of different sensors belonging to different fault modes.The fusion levels were used to determine the weights of different sensors during fusion,thus the membership degrees after information fusion between different sensors with similar characteristics were obtained.Then,the fused membership degrees were converted into the basic probability assignment functions.Finally,the information of different characteristics was fused on the basis of the evidence theory.Experimental results showed that the four cases including normal running,air loss of air spring,without anti-yaw shock absorber and without transverse shock absorber can be identified effectively with the proposed method,and the

  3. 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.

  4. Brain training game boosts executive functions, working memory and processing speed in the young adults: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Rui Nouchi

    Full Text Available BACKGROUND: Do brain training games work? The beneficial effects of brain training games are expected to transfer to other cognitive functions. Yet in all honesty, beneficial transfer effects of the commercial brain training games in young adults have little scientific basis. Here we investigated the impact of the brain training game (Brain Age on a wide range of cognitive functions in young adults. METHODS: We conducted a double-blind (de facto masking randomized controlled trial using a popular brain training game (Brain Age and a popular puzzle game (Tetris. Thirty-two volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris. Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into eight categories (fluid intelligence, executive function, working memory, short-term memory, attention, processing speed, visual ability, and reading ability. RESULTS AND DISCUSSION: Our results showed that commercial brain training game improves executive functions, working memory, and processing speed in young adults. Moreover, the popular puzzle game can engender improvement attention and visuo-spatial ability compared to playing the brain training game. The present study showed the scientific evidence which the brain training game had the beneficial effects on cognitive functions (executive functions, working memory and processing speed in the healthy young adults. CONCLUSIONS: Our results do not indicate that everyone should play brain training games. However, the commercial brain training game might be a simple and convenient means to improve some cognitive functions. We believe that our findings are highly relevant to applications in educational and clinical fields

  5. High-speed Stochastic Fatigue Testing

    DEFF Research Database (Denmark)

    Brincker, Rune; Sørensen, John Dalsgaard

    1990-01-01

    Good stochastic fatigue tests are difficult to perform. One of the major reasons is that ordinary servohydraulic loading systems realize the prescribed load history accurately at very low testing speeds only. If the speeds used for constant amplitude testing are applied to stochastic fatigue...... the analog control device remain as the basic control mechanism in the system, but distorting the input signal by computer in order to minimize the errors of the load history extremes. The principle proves to be very efficient to reduce all kinds of system errors and has shown to be able to increase...

  6. Comparison between two types of anaerobic speed endurance training in competitive soccer players

    DEFF Research Database (Denmark)

    Mohr, Magni; Krustrup, Peter

    2016-01-01

    speed endurance production (SEP) or speed endurance maintenance (SEM) training (two additional sessions/wk for 4 weeks) during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2) and a repeated sprint test (RST) pre- and postintervention. Yo-Yo IR2 performance...

  7. DeceptiBike: Assessing the Perception of Speed Deception in a Virtual Reality Training Bike System

    DEFF Research Database (Denmark)

    Löchtefeld, Markus; Krüger, Antonio; Gellersen, Hans

    2016-01-01

    investigate the performance of participants exposed to speed deception in virtual reality environments controlled by a training bike. With DeceptiBike we created a bike simulator that allows to manipulate speed perception via visual- and haptic cues. Our results show that we effectively can increase the users...

  8. 33 CFR 84.24 - High-speed craft.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false High-speed craft. 84.24 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.24 High-speed craft. (a) The masthead light of high-speed craft with a length to breadth ratio of less than 3.0 may be placed at...

  9. 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.

  10. High Speed Switching Micoplasma in High Pressure Gases

    Science.gov (United States)

    Wakim, Dani; Staack, David

    2012-10-01

    Micro-plasma discharges with switching times approaching 1 ns are studied at pressures from 1 to 16 atm. Applications of these devices are robust high speed switching transistors able to withstand electric interference, high temperatures and harsh environments. Measured discharge conditions at 250 psia in Nitrogen are: gas temperature 2900 K, discharge diameter ˜7 μm and electron density ˜10^17 cm-3. High speed switching is achieved by taking advantage of rapid dynamics of instabilities at high pressure and high electron density. The capacitance and inductance of the circuit also significantly affect transients. Tradeoffs are observed in switching times. By reducing capacitances from 10 pF to ˜1pF attainment of steady state conditions can be reduced from 1 us to ˜ 20 ns. However current rise times increase from 1 ns at high capacitance to 20 ns at low capacitance. A decrease in switching time with increased pressure is also observed. Also investigated are configurations with a third electrode acting as a gate or trigger and various high temperature (>2000K) materials such as platinum rhodium alloys and ceria stabilized zirconia ceramics for device fabrication.

  11. 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 (CTΔΣ) 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

  12. 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 (CTΔΣ) 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 th

  13. Installation position determination of wind speed sensors on steel pole along a high-speed railway

    Institute of Scientific and Technical Information of China (English)

    熊小慧; 梁习锋

    2016-01-01

    In order to consider the influence of steel pole on the measurement of wind speed sensors and determinate the installation position of wind speed sensors, the flow field around wind speed sensors was investigated. Based on the three-dimensional steady Reynolds-averaged Navier-Stokes equations andk-ε double equations turbulent model, the field flow around the wind speed sensor and the steel pole along a high-speed railway was simulated on an unstructured grid. The grid-independent validation was conducted and the accuracy of the present numerical simulation method was validated by experiments and simulations carried out by previous researchers. Results show that the steel pole has a significant influence on the measurement results of wind speed sensors. As the distance between two wind speed sensors is varied from 0.3 to 1.0 m, the impact angles are less than ±20°, it is proposed that the distance between two wind speed sensors is 0.8 m at least, and the interval between wind speed sensors and the steel pole is more than 1.0 m with the sensors located on the upstream side.

  14. Improving word reading speed: individual differences interact with a training focus on successes or failures

    NARCIS (Netherlands)

    Steenbeek-Planting, E.G.; Bon, W.H.J. van; Schreuder, R.

    2012-01-01

    The effect of two training procedures on the development of reading speed in poor readers is examined. One training concentrates on the words the children read correctly (successes), the other on the words they read incorrectly (failures). Children were either informed or not informed about the

  15. 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.

  16. 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...

  17. 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...

  18. High speed twin roll casting of 6061 alloy strips

    OpenAIRE

    T. Haga; Sakaguchi, H.; H. Watari; S. Kumai

    2008-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin strips of two aluminum alloys:6061 and recycled 6061. Mechanical properties of the roll cast 6061 and recycled 6061 strips were investigated inthe frame of this purpose.Design/methodology/approach: Methods used in the present study were high speed twin roll caster and lowtemperature casting. These methods were used to realize rapid solidification and increase the casting speed.Findings: are that 6061 and rec...

  19. The effect of two speed endurance training regimes on performance of soccer players

    DEFF Research Database (Denmark)

    Iaia, F Marcello; Fiorenza, Matteo; Perri, Enrico;

    2015-01-01

    (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg) reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6) or speed endurance maintenance (SEM; n = 7) training, three times per wk. SEP training consisted of 6......-8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6-8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (ptotal time in a repeated sprint ability test (RSAt) by 2.5%. SEM training improved...

  20. Evaluating the time limit at maximum aerobic speed in elite swimmers. Training implications.

    Science.gov (United States)

    Renoux, J C

    2001-12-01

    The aim of the present study was to make use of the concepts of maximum aerobic speed (MAS) and time limit (tlim) in order to determine the relationship between these two elements, and this in an attempt to significantly improve both speed and swimming performance during a training season. To this same end, an intermittent training model was used, which was adapted to the value obtained for the time limit at maximum aerobic speed. During a 12 week training period, the maximum aerobic speed for a group of 9 top-ranking varsity swimmers was measured on two occasions, as was the tlim. The values generated indicated that: 1) there was an inverse relationship between MAS and the time this speed could be maintained, thus confirming the studies by Billat et al. (1994b); 2) a significant increase in MAS occurred over the 12 week period, although no such evolution was seen for the tlim; 3) there was an improvement in results; 4) the time limit could be used in designing a training program based on intermittent exercises. In addition, results of the present study should allow swimming coaches to draw up individualized training programs for a given swimmer by taking into consideration maximum aerobic speed, time limit and propelling efficiency.

  1. Effects of Continuous and Interval Training on Running Economy, Maximal Aerobic Speed and Gait Kinematics in Recreational Runners.

    Science.gov (United States)

    González-Mohíno, Fernando; González-Ravé, José M; Juárez, Daniel; Fernández, Francisco A; Barragán Castellanos, Rubén; Newton, Robert U

    2016-04-01

    The purpose of this study was to evaluate the effects on running economy (RE), V[Combining Dot Above]O2max, maximal aerobic speed (MAS), and gait kinematics (step length [SL] and frequency, flight and contact time [CT]) in recreational athletes, with 2 different training methods, Interval and Continuous (CON). Eleven participants were randomly distributed in an interval training group (INT; n = 6) or CON training group (CON; n = 5). Interval training and CON performed 2 different training programs (95-110% and 70-75% of MAS, respectively), which consisted of 3 sessions per week during 6 weeks with the same external workload (%MAS × duration). An incremental test to exhaustion was performed to obtain V[Combining Dot Above]O2max, MAS, RE, and gait variables (high speed camera) before and after the training intervention. There was a significant improvement (p ≤ 0.05) in RE at 60 and 90% of MAS by the CON group; without changes in gait. The INT group significantly increased MAS and higher stride length at 80, 90, and 100% of MAS and lower CT at 100% of MAS. As expected, training adaptations are highly specific to the overload applied with CON producing improvements in RE at lower percentage of MAS whereas INT produces improvements in MAS. The significantly increased stride length and decreased CT for the INT group are an important outcome of favorable changes in running gait.

  2. Structural vulnerability and intervention of high speed railway networks

    Science.gov (United States)

    Zhang, Jianhua; Hu, Funian; Wang, Shuliang; Dai, Yang; Wang, Yixing

    2016-11-01

    This paper employs complex network theory to assess the structural vulnerability of high speed railway networks subjected to two different malicious attacks. Chinese, US and Japanese high speed railway networks are used to discuss the vulnerable characteristics of systems. We find that high speed railway networks are very fragile when suffering serious disturbances and two attack rules can cause analogous damages to one high speed railway network, which illustrates that the station with large degree possesses high betweenness, vice versa. Meanwhile, we discover that Japanese high speed railway network has the best global connectivity, but Chinese high speed railway network has the best local connectivity and possesses the largest transport capacity. Moreover, we find that there exist several redundant paths in Chinese high speed railway network and discover the critical stations of three HSRNs. Furthermore, the nearest-link method is adopted to implement topological interventions and to improve the connectivity and reliability of high speed railway networks. In addition, the feasibility and effectiveness of topological interventions are shown by simulations.

  3. 多物理场耦合激励下的高铁车内中频噪声计算%High-speed train medium-f requency interior noise calculation under multi-physical-field coupling excitations

    Institute of Scientific and Technical Information of China (English)

    毛杰; 郝志勇; 孙强; 郑旭; 马晓龙; 张强

    2015-01-01

    Hybrid finite element‐statistical energy analysis (FE‐SEA) theory was employed to construct the medium‐frequency acoustic model of a high‐speed railway train coach .Acoustic attributes of trim parts were taken into consideration to study the interior noise of a fully‐trimmed coach .The calculation scheme for the high‐speed train interior structural radiated noise under multi‐physical‐field coupled excitations was proposed ,w hich adopted fast multi‐pole boundary element analysis ,rigid multi‐body dynamics ,and large‐eddy simulation integrated with Ffowcs Williams‐Hawkings (FW‐H) acoustic analogy method to extract the wheel‐rail noise ,secondary suspension forces ,and aerodynamic noise at 350 km/h .The excitations were coupled to stimulate the hybrid train model to calculate the interior noise in the frequency range of 200~1600 Hz .Finally ,the simulated and measured sound pressure levels of an observation point w hich is 1 .2 m above the interior center floor at the same speed were contrasted .The results indicate that the changing trends of two curves are generally consistent ,and the deviation of the overall sound pressure level is 2 .7 dB ,which validates the accuracy of the hybrid model and coupled excitations in accordance with engineering permission .%采用混合有限元‐统计能量分析(FE‐SEA)理论搭建某高速列车车厢的中频声学模型,考虑内饰件的声学性能,研究整备车厢的车内噪声.提出多物理场耦合激励下的高速列车车内结构辐射噪声计算方案,分别采用快速多极边界元、刚性多体动力学和大涡模拟结合Ffowcs Williams‐Hawkings (FW‐H)声类比法提取了350 km/h下的轮轨噪声、二系悬挂力和空气动力噪声,将这些激励源耦合后作用在列车混合模型上,计算200~1600 Hz内的车内噪声.在相同车速下,选取车内中心距离地板1.2m高度处的仿真与试验声压级

  4. High speed matrix processors using floating point representation

    Energy Technology Data Exchange (ETDEWEB)

    Birkner, D.A.

    1980-01-01

    The author describes the architecture of a high-speed matrix processor which uses a floating-point format for data representation. It is shown how multipliers and other LSI devices are used in the design to obtain the high speed of the processor.

  5. High-Speed Photo-Polarimetry of Magnetic Cataclysmic Variables

    Directory of Open Access Journals (Sweden)

    S. B. Potter

    2015-02-01

    Full Text Available I review recent highlights of the SAAO High-speed Photo-POlarimeter (HIPPO on the study of magnetic Cataclysmic Variables. Its high-speed capabilities are demonstrated with example observations made of the intermediate polar NY Lup and the polar IGRJ14536-5522.

  6. 高速列车万向轴动不平衡检测的EEMD-Hankel-SVD方法%Detection of the Dynamic Imbalance with Cardan Shaft in High-speed Train Applying EEMD-Hankel-SVD

    Institute of Scientific and Technical Information of China (English)

    丁建明; 林建辉; 赵洁

    2015-01-01

    A new method of detecting dynamic imbalance with cardan shaft in the high-speed train is proposed applying the combination between ensemble empirical model decomposition(EEMD), Hankel matrix and singular value decomposition(SVD) contrary to the aliasing defect between the adjacent intrinsic model functions existing in the EEMD. The vibration acceleration signals of gimbal are decomposed through EEMD to get the different intrinsic model components. The Hankel matrix, which is constructed throng the single decomposition model component, is orthogonally executed through SVD. The key singular values are selected to reconstruct vibration signs on the base of the key stack of singular values. Fourier spectrum of the reconstructed signal is applied to detect dynamic imbalance with shaft and eliminates clutter spectrum caused by the aliasing defect between the adjacent intrinsic model functions, highlights the failure characteristics. The method is verified by test data in the condition of dynamic imbalance, the results show this method can effectively detect the fault vibration characteristics caused by cardan shaft dynamic imbalance and extract the nature vibration features. With comparison to the simple EEMD, the clarity and failure characterization force are significantly improved.%针对聚合经验模式分解(Ensemble empirical model decomposition, EEMD)的等效滤波特性依然存在模式分量间频带重叠较大的根本缺陷,提出一种高速列车万向轴动不平衡动态检测的新方法.该方法的核心是对万向节安装机座的振动信号进行EEMD分解得到基本模式分量,应用基本模式分量信号来构造Hankel矩阵,对该矩阵进行正交化奇异值(Singular value decomposition, SVD)分解,以奇异值关键叠层作为奇异值的选择准则对信号进行重构,应用重构信号的傅里叶谱来检测高速列车万向轴的动不平衡,消除 EEMD 分解模式频带重叠对故障特征的淹没和混淆效应,提高了

  7. Sound Transmission Loss of Sandwich Panels Floor of High-speed Trains%高速列车夹芯地板结构隔声特性研究

    Institute of Scientific and Technical Information of China (English)

    孙加平; 张丽荣; 孙海荣; 王志海; 王永成

    2014-01-01

    采用传递矩阵法,建立高速列车内地板的声学特性分析模型,探索不同三明治夹芯板材料和结构对高速列车内地板隔声特性的影响,并根据内地板结构的传递损失评价具有不同参数的三明治夹芯板的隔声性能。通过不同的表层材质(木材、铝材、钢材)、厚度和蜂窝夹层密度,进行了内地板隔声量变化规律的分析和比较。探寻拟定隔声性能优越的三明治夹芯板材料类型和结构型式。结果表明,(1)表层夹板厚度一定,钢材作为表层材料,内地板隔声量最好,其次是铝材,最后是木材;(2)表层厚度影响,木材夹层板,厚度每增加1 mm,各个频段隔声量增加1 dB~1.5 dB。铝材夹层板,厚度每增加1 mm,各个频段隔声量增加1 dB~3 dB。钢材夹层板,厚度每增加1 mm,各个频段隔声量增加1 dB~5 dB;(3)蜂窝板密度降低一半,内地板隔声量有增加趋势,但影响较小。%The model for analyzing the acoustic characteristics of interior floor of high-speed trains is established. The sandwich panels with three different materials, timber, aluminum and steel, and the honeycomb cores with different thicknesses and densities, are used for the interior floor. The transfer matrix method is employed for analyzing the model. The sound insulation effects of different materials and structures of the sandwich panels are evaluated and compared. The results show that (1) when the thickness of the surface layer of the sandwich panel keeps constant, the interior floor with steel as the surface layer has the best sound transmission loss effect, and followed by aluminum, and timber;(2) when the thickness of the surface layer is additionally increased by 1 mm, the transmission loss of the floor can be increased by 1 dB~1.5 dB for timber sandwich panel, 1 dB ~3 dB for aluminum sandwich panel and 1 dB ~5 dB for steel sandwich panel respectively;(3) the density

  8. High Speed Linear Induction Motor Efficiency Optimization

    Science.gov (United States)

    2005-06-01

    rotor d. 2 heightrotor ae + overhang length scon p-r length~~ 0 .5 7eto siemens .85 cru=5. 7-10 7 ___ se esc l:-z2.-17 siemens width: 100ikn 3.5 N:= 3...Vsnhs1482 Fp ot( slip1 ot) I K_______iplo)slppo speed ( slippiot) Vsych’ I~ nx sip (lipot 7t 2.106 1.5-.10 6 _ F~l0(s 5-100~ 5 50~ 0.9 0.8 0.7 0.6 0.5

  9. High Speed Laser 3D Measurement System

    Institute of Scientific and Technical Information of China (English)

    SONG Yuan-he; FAN Chang-zhou; GUO Ying; LI Hong-wei; ZHAO Hong

    2003-01-01

    Using the method of line structure light produced by a laser diode,three dimensional profile measurement is deeply researched.A hardware circuit developed is used to get the center position of light section for the improvement of the measurement speed.A double CCD compensation technology is used to improve the measurement precision. An easy and effective calibration method of the least squares to fit the parameter of system structure is used to get the relative coordinate relationship of objects and images of light section in the directions of height and axis. Sensor scanning segment by segment and layer by layer makes the measurement range expand greatly.

  10. Maneuverability Estimation of High-Speed Craft

    Science.gov (United States)

    2015-06-01

    different g-forces. The air-to-surface missile (Penguin anti-ship missile , AGM-114B/K/M Hellfire missile ) has a maximum speed around Mach 1.2. I assume...attacked by a missile . Three different attacking situations are analyzed in missile -vessel interactions for the safety of the vessel, and the optimum...distance has been found to start the escape maneuver. According to these escape situations, the missile should maintain a certain g-force to make an

  11. High Speed Sonar Array Depressor Program

    Science.gov (United States)

    1981-11-30

    were conducted in the Exuma Sound In August 1981. 33 Report 12482 1000 4000 z 3000 2000 - 500 1000 0 1I 0 0 5 10 15 20 25 30 SPEED-KNOTS 700 1:11 IS z...the ONR Sea Trial 1A6 on the R/V ATHENA. The depressor was deployed during that portion of the trials occuring on 5, 6, 7 and 8 August 1981 in Exuma ...Before the Exuma Sound runs the bolt holes in tVe depressor were permanently plugged and faired. From then on no relation was seen between the sign

  12. Spontaneous sidebanding in high speed rotordynamics

    Science.gov (United States)

    Ehrich, F. F.

    1992-10-01

    It is noted that the spontaneous sideband spacing frequency seems to be a whole number fraction (1/J) of the operating speed which indicates that the wave form is periodic and completes a full cycle every J rotations of the rotor. Employing a numerical model of a rotor that simulates local contact with a stator in close proximity as a bilinear spring, studies have been conducted to explore the circumstances for this spontaneous sidebanding. Two general classes of this type of response are determined in a system that is effectively single-degree-of-freedom.

  13. Buzz Groups and Videotape Speed Training at Ernst & Ernst

    Science.gov (United States)

    Larick, Donald

    1971-01-01

    Using videotape for short lectures at the end of buzz group problems takes the burden off staff when training 360 auditors in computer techniques. Money conscious Ernst & Ernst puts the cost at $1.90 per lecture, per man. (Journal/EB)

  14. Concurrent speed endurance and resistance training improves performance, running economy, and muscle NHE1 in moderately trained runners.

    Science.gov (United States)

    Skovgaard, Casper; Christensen, Peter M; Larsen, Sonni; Andersen, Thomas Rostgaard; Thomassen, Martin; Bangsbo, Jens

    2014-11-15

    The purpose of this study was to examine whether speed endurance training (SET, repeated 30-s sprints) and heavy resistance training (HRT, 80-90% of 1 repetition maximum) performed in succession are compatible and lead to performance improvements in moderately trained endurance runners. For an 8-wk intervention period (INT) 23 male runners [maximum oxygen uptake (V̇O(2max)) 59 ± 1 ml·min(-1)·kg(-1); values are means ± SE] either maintained their training (CON, n = 11) or performed high-intensity concurrent training (HICT, n = 12) consisting of two weekly sessions of SET followed by HRT and two weekly sessions of aerobic training with an average reduction in running distance of 42%. After 4 wk of HICT, performance was improved (P < 0.05) in a 10-km run (42:30 ± 1:07 vs. 44:11 ± 1:08 min:s) with no further improvement during the last 4 wk. Performance in a 1,500-m run (5:10 ± 0:05 vs. 5:27 ± 0:08 min:s) and in the Yo-Yo IR2 test (706 ± 97 vs. 491 ± 65 m) improved (P < 0.001) only following 8 wk of INT. In HICT, running economy (189 ± 4 vs. 195 ± 4 ml·kg(-1)·km(-1)), muscle content of NHE1 (35%) and dynamic muscle strength was augmented (P < 0.01) after compared with before INT, whereas V̇O(2max), muscle morphology, capillarization, content of muscle Na(+)/K(+) pump subunits, and MCT4 were unaltered. No changes were observed in CON. The present study demonstrates that SET and HRT, when performed in succession, lead to improvements in both short- and long-term running performance together with improved running economy as well as increased dynamic muscle strength and capacity for muscular H(+) transport in moderately trained endurance runners.

  15. Intelligent high-speed cutting database system development

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,the components of a high-speed cutting system are analyzed firstly.The component variables of the high-speed cutting system are classified into four types:uncontrolled variables,process variables,control variables,and output variables.The relationships and interactions of these variables are discussed.Then,by analyzing and comparing intelligent reasoning methods frequently used,the hybrid reasoning is employed to build the high-speed cutting database system.Then,the data structures of high-speed cutting case base and databases are determined.Finally,the component parts and working process of the high-speed cutting database system on the basis of hybrid reasoning are presented.

  16. Wake flow characteristics at high wind speed

    DEFF Research Database (Denmark)

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

    2016-01-01

    power. In the present study we simulate the wake flow for a row of turbines with the wind aligned with the row using a simplified approach. The velocity deficit, being a function of the thrust coefficient, is simulated based on the BEM solution for wake expansion. An axis-symmetric boundary layer...... equation model (the same as implemented in the DWM model) is subsequently used to develop the deficit down to the next turbine, and then the approach is successively repeated. Simulation results for four different spacing’s in a row with eight turbines show that there are two major flow regimes...... in the intersection region between the two flow regimes a strong variation in power and thrust occur, e.g. going from almost zero power to rated power for a wind speed change of 4m/s. Another result is that the inflow profile to the last turbine in the row at a wind speed of 16m/s for a spacing of 3D shows...

  17. Effect of welding current and speed on occurrence of humping bead in high-speed GMAW

    Institute of Scientific and Technical Information of China (English)

    Chen Ji; Wu Chuansong

    2009-01-01

    The developed mathematical model of humping formation mechanism in high-speed gas metal arc welding (GMAW) is used to analyze the effects of welding current and welding speed on the occurrence of humping bead. It considers both the momentum and heat content of backward flowing molten jet inside weld pool. Three-dimensional geometry of weld pool, the spacing between two adjacent humps and hump height along humping weld bead are calculated under different levels of welding current and welding speed. It shows that wire feeding rate, power intensity and the moment of backward flowing molten jet are the major factors on humping bead formation.

  18. Evaluation of Dynamic Load Factors for a High-Speed Railway Truss Arch Bridge

    Directory of Open Access Journals (Sweden)

    Ding Youliang

    2016-01-01

    Full Text Available Studies on dynamic impact of high-speed trains on long-span bridges are important for the design and evaluation of high-speed railway bridges. The use of the dynamic load factor (DLF to account for the impact effect has been widely accepted in bridge engineering. Although the field monitoring studies are the most dependable way to study the actual DLF of the bridge, according to previous studies there are few field monitoring data on high-speed railway truss arch bridges. This paper presents an evaluation of DLF based on field monitoring and finite element simulation of Nanjing DaShengGuan Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The DLFs in different members of steel truss arch are measured using monitoring data and simulated using finite element model, respectively. The effects of lane position, number of train carriages, and speed of trains on DLF are further investigated. By using the accumulative probability function of the Generalized Extreme Value Distribution, the probability distribution model of DLF is proposed, based on which the standard value of DLF within 50-year return period is evaluated and compared with different bridge design codes.

  19. 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...

  20. The effects of variable speed and drive train component efficiencies on wind turbine energy capture

    Energy Technology Data Exchange (ETDEWEB)

    Fingersh, L.J.; Robinson, M.C.

    1998-05-01

    A wind turbine rotor achieves optimal aerodynamic efficiency at a single tip-speed ratio (TSR). To maintain that optimal TSR and maximize energy capture in the stochastic wind environment, it is necessary to employ variable-speed operation. Conventional constant-speed wind turbines have, in the past, been converted into variable-speed turbines by attaching power electronics to the conventional induction generator and gearbox drive train. Such turbines have shown marginal, if any, improvement in energy capture over their constant-speed counterparts. These discrepancies have been shown to be the result of drive train components that are not optimized for variable-speed operation. Traditional drive trains and power electronic converters are designed to achieve maximum efficiency at full load and speed. However, the main energy producing winds operate the turbine at light load for long periods of time. Because of this, significant losses to efficiency occur. This investigation employs a quasi-static model to demonstrate the dramatic effect that component efficiency curves can have on overall annual energy capture.

  1. RIDING THE HIGH-SPEED RAILS

    Institute of Scientific and Technical Information of China (English)

    LAN XINZHEN

    2010-01-01

    @@ Travel between Wuhan,capital of central China's Hubei Province,and Guangzhou,capital of Guangdong Province in south China,used to take 10 hours.But now,the 1,000-km journey can be made in three hours.When factoring in time spent getting to the airport and then waiting to board the aircraft,travel time between the two cities by air or rail is roughly the same.But the cost effectiveness of train travel trumps air utansportation,luring a considerable number of people to stay grounded when traveling.

  2. High-speed camera characterization of voluntary eye blinking kinematics.

    Science.gov (United States)

    Kwon, Kyung-Ah; Shipley, Rebecca J; Edirisinghe, Mohan; Ezra, Daniel G; Rose, Geoff; Best, Serena M; Cameron, Ruth E

    2013-08-01

    Blinking is vital to maintain the integrity of the ocular surface and its characteristics such as blink duration and speed can vary significantly, depending on the health of the eyes. The blink is so rapid that special techniques are required to characterize it. In this study, a high-speed camera was used to record and characterize voluntary blinking. The blinking motion of 25 healthy volunteers was recorded at 600 frames per second. Master curves for the palpebral aperture and blinking speed were constructed using palpebral aperture versus time data taken from the high-speed camera recordings, which show that one blink can be divided into four phases; closing, closed, early opening and late opening. Analysis of data from the high-speed camera images was used to calculate the palpebral aperture, peak blinking speed, average blinking speed and duration of voluntary blinking and compare it with data generated by other methods previously used to evaluate voluntary blinking. The advantages of the high-speed camera method over the others are discussed, thereby supporting the high potential usefulness of the method in clinical research.

  3. High speed sampling circuit design for pulse laser ranging

    Science.gov (United States)

    Qian, Rui-hai; Gao, Xuan-yi; Zhang, Yan-mei; Li, Huan; Guo, Hai-chao; Guo, Xiao-kang; He, Shi-jie

    2016-10-01

    In recent years, with the rapid development of digital chip, high speed sampling rate analog to digital conversion chip can be used to sample narrow laser pulse echo. Moreover, high speed processor is widely applied to achieve digital laser echo signal processing algorithm. The development of digital chip greatly improved the laser ranging detection accuracy. High speed sampling and processing circuit used in the laser ranging detection system has gradually been a research hotspot. In this paper, a pulse laser echo data logging and digital signal processing circuit system is studied based on the high speed sampling. This circuit consists of two parts: the pulse laser echo data processing circuit and the data transmission circuit. The pulse laser echo data processing circuit includes a laser diode, a laser detector and a high sample rate data logging circuit. The data transmission circuit receives the processed data from the pulse laser echo data processing circuit. The sample data is transmitted to the computer through USB2.0 interface. Finally, a PC interface is designed using C# language, in which the sampling laser pulse echo signal is demonstrated and the processed laser pulse is plotted. Finally, the laser ranging experiment is carried out to test the pulse laser echo data logging and digital signal processing circuit system. The experiment result demonstrates that the laser ranging hardware system achieved high speed data logging, high speed processing and high speed sampling data transmission.

  4. Characterizing speed-independence of high-level designs

    DEFF Research Database (Denmark)

    Kishinevsky, Michael; Staunstrup, Jørgen

    1994-01-01

    types, and internal as well as external non-determinism. This makes it possible to verify the speed-independence of a design without providing an explicit realization of the environment. The verification can be done mechanically. A number of experimental designs have been verified including a speed......This paper characterizes the speed-independence of high-level designs. The characterization is a condition on the design description ensuring that the behavior of the design is independent of the speeds of its components. The behavior of a circuit is modeled as a transition system, that allows data...

  5. Review of High-Speed Fiber Optic Grating Sensors Systems

    Energy Technology Data Exchange (ETDEWEB)

    Udd, E; Benterou, J; May, C; Mihailov, S J; Lu, P

    2010-03-24

    Fiber grating sensors can be used to support a wide variety of high speed measurement applications. This includes measurements of vibrations on bridges, traffic monitoring on freeways, ultrasonic detection to support non-destructive tests on metal plates and providing details of detonation events. This paper provides a brief overview of some of the techniques that have been used to support high speed measurements using fiber grating sensors over frequency ranges from 10s of kHz, to MHZ and finally toward frequencies approaching the GHz regime. Very early in the development of fiber grating sensor systems it was realized that a high speed fiber grating sensor system could be realized by placing an optical filter that might be a fiber grating in front of a detector so that spectral changes in the reflection from a fiber grating were amplitude modulated. In principal the only limitation on this type of system involved the speed of the output detector which with the development of high speed communication links moved from the regime of 10s of MHz toward 10s of GHz. The earliest deployed systems involved civil structures including measurements of the strain fields on composite utility poles and missile bodies during break tests, bridges and freeways. This was followed by a series of developments that included high speed fiber grating sensors to support nondestructive testing via ultrasonic wave detection, high speed machining and monitoring ship hulls. Each of these applications involved monitoring mechanical motion of structures and thus interest was in speeds up to a few 10s of MHz. Most recently there has been interest in using fiber grating to monitor the very high speed events such as detonations and this has led to utilization of fiber gratings that are consumed during an event that may require detection speeds of hundreds of MHz and in the future multiple GHz.

  6. Incorporating YBCO Coated Conductors in High-speed Superconducting Generators

    Science.gov (United States)

    2008-07-01

    4.0 kW/lb (8.82 kW/kg). The machine configuration chosen by GE for design was a homopolar inductor alternator (HIA) which locates the...extremely severe ac loss environment. Even if this is ultimately impossible for high speed generators, it may not preclude lower speed motors and

  7. High-speed display system for animation using multimicrocomputer

    Energy Technology Data Exchange (ETDEWEB)

    Onda, K.; Oako, Y.

    1983-01-01

    A high-speed display system architecture for computer animation is proposed. Many picture memories, each of which is connected to a microcomputer, and display controller are used for producing and displaying pictures in parallel. This system can be realized with low-speed processors without specific hardwares to display natural movement. 1 ref.

  8. HULL GESTURE AND RESISTANCE PREDICTION OF HIGH-SPEED VESSELS*

    Institute of Scientific and Technical Information of China (English)

    NI Chong-ben; ZHU Ren-chuan; MIAO Guo-ping; FAN Ju

    2011-01-01

    Since trim and sinkage are significant while vessels are advancing forward with high speed, the predicted vessel resistance based on restrained model theory or experiment may not be real resistance of vessels during voyage. It is necessary to take the influence of hull gesture into account for oredicting the resistance of high-speed ship. In the present work the resistance problem of high speed ship is treated with the viscous flow theory, and the dynamic mesh technique is adopted to coincide with variation of hull gesture of high speed vessel on voyage. The simulation of the models of S60 ship and a trimaran moving in towing tank with high speed are conducted by using the above theory and technique. The corresponding numerical results are in good agreement with the experimental data. It indicates that the resistance prediction for high speed vessels should take hull gesture into consideration and the dynamic mesh method proposed here is effective in calculating the resistance of high speed vessels.

  9. Application Of High Speed Photography In Science And Technology

    Science.gov (United States)

    Wu Ji-Zong, Wu; Yu-Ju, Lin

    1983-03-01

    The service works in high-speed photography carried out by the Department of Precision Instruments, Tianjin University are described in this paper. A compensation type high-speed camera was used in these works. The photographic methods adopted and better results achieved in the studies of several technical fields, such as velocity field of flow of overflow surface of high dam, combustion process of internal combustion engine, metal cutting, electrical are welding, experiment of piling of steel tube piles for supporting the marine platforms and characteristics of motion of wrist watch escape mechanism and so on are illustrated in more detail. As the extension of human visual organs and for increasing the abi-lities of observing and studying the high-speed processes, high-speed photography plays a very important role. In order to promote the application and development on high-speed photography, we have carried out the consultative and service works inside and outside Tianjin Uni-versity. The Pentazet 35 compensation type high-speed camera, made in East Germany, was used to record the high-speed events in various kinds of technical investigations and necessary results have been ob-tained. 1. Measurement of flow velocity on the overflow surface of high dam. In the design of a key water control project with high head, it is extremely necessary to determinate various characteristics of flow velocity field on the overflow surface of high dam. Since the water flow on the surface of high overflow dam possesses the features of large flow velocity and shallow water depth, therefore it is difficult to use the conventional current meters such as pilot tube, miniature cur-rent meter or electrical measuring methods of non-electrical quantities for studying this problem. Adopting the high-speed photographic method to study analogously the characteristics of flow velocity field on the overflow surface of high dam is a kind of new measuring method. People

  10. Influence of ballastless track constraint on the seismic responses of high-speed railway train-bridge system%无砟轨道约束对高速铁路列车-桥梁系统地震响应的影响

    Institute of Scientific and Technical Information of China (English)

    陈令坤; 蒋丽忠; 余志武

    2013-01-01

    The high-speed train (motor car/trailer car) model with 38 DOFs was build up ,based on the nonlinear Hertz contact theory and the Kalker creep theory ,the strong earthquake records of PEER-NGA were introduced ,the fine model of the high-speed train-ballastless track/rail-box girder-bearing-pier-pier-soil were established in this paper ,the influence of bearing and pile-soil dynamic interaction were considered ,CRTSⅡslab ballastless track and 32 m span simply-supported box girder bridge were studied ,the MATLAB software was developed to calculated the seismic responses and train-running safety during earthquake of high-speed railway train-bridge system ,and the comparative analysis was carried out .The calculated results show that ,the seismic response of the system were larger compared with the high-speed train-ballastless track-bridge system ,the constraint influence of the ballastless track can not be ignored ,the ballastless track can effectively improve the train-running safety behavior of vehi-cle with/without earthquake action ;the pulse like fault earthquake can significantly affected the respon-ses of high-speed railway train-ballastless track-bridge system and train-running safety .%建立了38自由度高速列车(动车/拖车)空间振动模型,基于非线性Hertz接触理论和Kalker线性蠕滑理论,引进PEER-NGA强震记录,建立地震作用下的高速铁路列车-无砟轨道/钢轨-桥梁-支座-桥墩-桩土系统精细计算模型,考虑支座刚度和桩土作用及近场地震效应的影响,以高速铁路32 m跨简支箱梁桥和CRTSⅡ板式无砟轨道为研究对象,编制了MATLAB程序,计算了有/无砟轨道约束下高速列车-桥梁时系统的地震响应。计算结果表明,不考虑三层无砟轨道时列车-桥梁系统模型由于桥梁刚度过大,列车-无砟轨道-桥梁系统的各项地震响应较列车-钢轨-桥梁系统有较大增加;对于有/无地震作用时,采用无砟轨道

  11. LONG TERM EFFECTS OF DIFFERENT TRAINING MODALITIES ON POWER, SPEED, SKILL AND ANAEROBIC CAPACITY IN YOUNG MALE BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Mindaugas Balciunas

    2006-03-01

    Full Text Available The purpose of this study was to identify the effect of 4 months of different training modalities on power, speed, skill and anaerobic capacity in 15-16 year old male basketball players. Thirty five Lithuanian basketball players were randomly assigned into three groups: power endurance group (intermittent exercise, PE, n = 12, general endurance group (continuous exercise, GE, n = 11 and control group (regular basketball training, CG, n = 12. The power endurance model was based in basketball game external structure whereas the general endurance model was based in continuous actions that frequently occur during the basketball game. The training models were used for 16 weeks in sessions conducted 3 times a week during 90 minutes each in the competition period. The following tests were performed: 20 m speed run, Squat jump, Countermovement jump, Running-based Anaerobic Sprint Test (RAST, 2 min. shooting test and the Shuttle ball-dribbling test. A 3×2 repeated measures ANOVA revealed no statistically significant differences in the 20 m speed run, Squat jump and Countermovement jump (p > 0.05. On the other hand, RAST showed significant increases in PE, with greater increases during the 5th and 6th runs. The PE training model also produced a significant improvement in the shuttle ball-dribbling test (48.7 ± 1.5 in the pretest, 45.5 ± 1.3 in the posttest, p < 0.05. Globally, our results suggest that both training modalities were able to maintain initial values of speed and power, however, the anaerobic capacity and skill increased only in the players from the power endurance group. Therefore, the power endurance training (intermittent high intensity exercise may be more beneficial to prepare junior players according to the game cardiovascular and metabolic specific determinants

  12. The effect of 40-m repeated sprint training on maximum sprinting speed, repeated sprint speed endurance, vertical jump, and aerobic capacity in young elite male soccer players.

    Science.gov (United States)

    Tønnessen, Espen; Shalfawi, Shaher A I; Haugen, Thomas; Enoksen, Eystein

    2011-09-01

    The purpose of this study was to examine the effect of 10 weeks' 40-m repeated sprint training program that does not involve strength training on sprinting speed and repeated sprint speed on young elite soccer players. Twenty young well-trained elite male soccer players of age (±SD) 16.4 (±0.9) years, body mass 67.2 (±9.1) kg, and stature 176.3 (±7.4) cm volunteered to participate in this study. All participants were tested on 40-m running speed, 10 × 40-m repeated sprint speed, 20-m acceleration speed, 20-m top speed, countermovement jump (CMJ), and aerobic endurance (beep test). Participants were divided into training group (TG) (n = 10) and control group (CG) (n = 10). The study was conducted in the precompetition phase of the training program for the participants and ended 13 weeks before the start of the season; the duration of the precompetition period was 26 weeks. The TG followed a Periodized repeated sprint training program once a week. The training program consisted of running 40 m with different intensities and duration from week to week. Within-group results indicate that TG had a statistically marked improvement in their performance from pre to posttest in 40-m maximum sprint (-0.06 seconds), 10 × 40-m repeated sprint speed (-0.12 seconds), 20- to 40-m top speed (-0.05 seconds), and CMJ (2.7 cm). The CG showed only a statistically notable improvement from pre to posttest in 10 × 40-m repeated sprint speed (-0.06 seconds). Between-group differences showed a statistically marked improvement for the TG over the CG in 10 × 40-m repeated sprint speed (-0.07 seconds) and 20- to 40-m top speed (-0.05 seconds), but the effect of the improvement was moderate. The results further indicate that a weekly training with repeated sprint gave a moderate but not statistically marked improvement in 40-m sprinting, CMJ, and beep test. The results of this study indicate that the repeated sprint program had a positive effect on several of the parameters tested

  13. High speed twin roll casting of 6016 strip

    OpenAIRE

    Haga, T.; Ikawa, M; H.Watari; S. Kumai

    2006-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin aluminum alloy strip. 6016aluminum alloy is used for sheet metal of the automobile. Therefore, casting of 6016 was tried in this study.Castability and characteristics of roll cast 6016 strip were investigated.Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designedto overcome the low castability of the twin roll caster.Findings: are as below. The 6016 could...

  14. High-speed AFM of human chromosomes in liquid

    Science.gov (United States)

    Picco, L. M.; Dunton, P. G.; Ulcinas, A.; Engledew, D. J.; Hoshi, O.; Ushiki, T.; Miles, M. J.

    2008-09-01

    Further developments of the previously reported high-speed contact-mode AFM are described. The technique is applied to the imaging of human chromosomes at video rate both in air and in water. These are the largest structures to have been imaged with high-speed AFM and the first imaging in liquid to be reported. A possible mechanism that allows such high-speed contact-mode imaging without significant damage to the sample is discussed in the context of the velocity dependence of the measured lateral force on the AFM tip.

  15. Trend on High-speed Power Line Communication Technology

    Science.gov (United States)

    Ogawa, Osamu

    High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

  16. AN ANALYSIS METHOD FOR HIGH-SPEED CIRCUIT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method for analyzing high-speed circuit systems is presented. The method adds transmission line end currents to the circuit variables of the classical modified nodal approach. Then the matrix equation describing high-speed circuit system can be formulated directly and analyzed conveniently for its normative form. A time-domain analysis method for transmission lines is also introduced. The two methods are combined together to efficiently analyze high-speed circuit systems having general transmission lines. Numerical experiment is presented and the results are compared with that calculated by Hspice.

  17. High speed high dynamic range high accuracy measurement system

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. 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.

  19. Train Headway Models and Carrying Capacity of Super-Speed Maglev System

    Science.gov (United States)

    He, Shiwei; Song, Rui; Eastham, Tony

    Train headway models are established by analyzing the operation of the Transrapid Super-speed Maglev System (TSMS). The variation in the minimum allowable headway for trains of different speeds and consists is studied under various operational constraints. A potential Beijing-Shanghai Maglev line is used as an illustration to undertake capacity analyses with the model and methods. The example shows that the headway models for analyzing the carrying capacity of Maglev systems are very useful for the configurational design of this new transport system.

  20. Development of an Intelligent System of Determinating the Coordinates and the Speed of the Train

    Directory of Open Access Journals (Sweden)

    Tarasov Evgenii M.

    2016-06-01

    Full Text Available Dynamic development of the country’s transport system leads to the increase of the length of highways, traffic interchange, including places of crossing with the railway. Notification time for crossing is determined by the maximum speed of the train, which is a significant disadvantage of the automatic crossing signaling. In reality the train speed is less than the estimated one, so the idles at transport intersection (crossing reach 30-30 minutes, creating not only inconveniences to vehicle traffic, but also unfavorable environmental conditions.

  1. EXPERIMENTAL INVESTIGATION ON SOUND SPEED PROPAGATING THROUGH HIGH SPEED AERATED FLOW IN OPEN CHANNEL

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experiment concerning the sound propaga-tion in aerated open channel flow was designed and conductedin a variable slope chute. The acquisition of sound data wasdone by the hydro-phones installed into the bottom wall of thechute. The data were analyzed and processed by the tape re-corder and a 3562A analyzer. The primary experimetal resultsindicated that the sound speed in aerated flow is varied with the air concentration and highly lower than each of the soundspeed in pure water or air. As released by the derived theoryformula, the minimum sound of 24m/s in aerated flow hap-pened when the air concentration achieved to 50%. This resultshows that the compressibility of high speed aerated flowshould be considered when the air concentration is near to50%. A criterion of compressibility of high speed aerated flowwas also giv. En in this paper.

  2. Pedagogical conditions necessary for effective speed-strength training of young football players (15-17 years old)

    OpenAIRE

    Bolotin, Alexander; Bakayev, Vladislav

    2017-01-01

    This study substantiates pedagogical conditions necessary for effective speed-strength training of young football players, such as careful selection of children and their retention throughout the whole period of football education; differentiation and individualization of speed-strength training of young football players; selection of the most effective means of developing speed and strength in young football players; balance of means of developing speed and strength of young football players...

  3. Berlin-Hamburg maglev train, an integral element of the Deutsche Bahn AG high-speed network; Die Magnetschnellbahn Berlin-Hamburg als integraler Bestandteil des Hochgeschwindigkeitsnetzes der Deutschen Bahn AG

    Energy Technology Data Exchange (ETDEWEB)

    Fechner, H. [Magnetschnellbahn-Planungsgesellschaft mbH, Schwerin (Germany)

    1998-12-31

    Berlin will soon be a turntable of traffic in Europa and a gateway to Eastern Europe. The Deutsche Bahn AG high-speed network is an important element. In September 1998, the Berlin-Hanover ICE connection was finished; the Berlin-Hamburg maglev connection will follow by 2005. Berlin will be the linking point of the two systems. (orig.) [Deutsch] Bereits in wenigen Jahren wird Berlin europaeische Verkehrsdrehscheibe und Tor zu Osteuropa sein. Eine Voraussetzung dafuer ist die Anbindung an das Hochgeschwindigkeitsstreckennetz der Deutschen Bahn. Ein wichtiger Schritt dahin ist die Inbetriebnahme der ICE-Verbindung Berlin - Hannover im September 1998; ein folgender wird die Magnetschnellbahnverbindung Berlin - Hamburg im Jahr 2005 sein. Im Hochgeschwindigkeitskonzept der Deutschen Bahn AG wird Berlin die Schnittstelle zwischen Rad/Schiene- und Magnetschwebetechnik bilden und die Verknuepfung der beiden Systeme erstmals demonstrieren. (orig.)

  4. INTELLIGENT TOOL CONDITION MONITORING IN HIGH-SPEED ...

    African Journals Online (AJOL)

    MR PRINCE

    work model has been developed for on-line condition monitoring of tool wear in high-speed ... degraded behaviours in wire electrical dis- ... mathematical models such as regression (Lin et ... an 11 kW Computer Numerical Controlled.

  5. 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...

  6. implementation and comparative study of a high speed multimode ...

    African Journals Online (AJOL)

    SUMAN HALDAR, SOUMITA HALDAR CHAKRABORTY, PRADIPTAMAITI, PRATIK KUMAR SINHA, PIJUSH BISWAS, Dr. AMITAVA SINHA

    2016-07-07

    Jul 7, 2016 ... The key feature of the work is reduced power and simple circuitry, without ... Keywords: Digital Communication, Multimode Modulator, High Speed ..... Implementation of Universal Modulator using Co-ordinate Rotation Digital ...

  7. 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...

  8. CSIR National Laser Centre develops a high speed OCT system

    CSIR Research Space (South Africa)

    Sharma, Ameeth

    2016-11-01

    Full Text Available impact areas and applications include polymer characterisation, surface and thin-film characterisation and biometrics. The National laser Centre has developed a high speed, large area optical coherence tomography (OCT) prototype for fingerprint scanning...

  9. 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.

  10. Supersonic stall flutter of high-speed fans

    Science.gov (United States)

    Adamczyk, J. J.; Stevans, W.; Jutras, R.

    1981-01-01

    An analytical model is proposed for predicting the onset of supersonic stall bending flutter in high-speed rotors. The analysis is based on a modified two-dimensional, compressible, unsteady actuator disk theory. The stability boundary predicted by the analysis is shown to be in good agreement with the measured boundary of a high speed fan. The prediction that the flutter mode would be a forward traveling wave sensitive to wheel speed and aerodynamic loading is confirmed by experimental measurements. In addition, the analysis shows that reduced frequency and dynamic head also play a significant role in establishing the supersonic stall bending flutter boundary of an unshrouded fan.

  11. High speed non-latching squid binary ripple counter

    Energy Technology Data Exchange (ETDEWEB)

    Silver, A.H.; Phillips, R.R.; Sandell, R.D.

    1985-03-01

    High speed, single flux quantum (SFQ) binary scalers are important components in superconducting analog-to-digital converters (ADC). This paper reviews the concept for a SQUID ADC and the design of an SFQ binary ripple counter, and reports the simulation of key components, and fabrication and performance of non-latching SQUID scalers and SFQ binary ripple counters. The SQUIDs were fabricated with Nb/Nb/sub 2/O/sub 5//PbIn junctions and interconnected by monolithic superconducting transmission lines and isolation resistors. Each SQUID functioned as a bistable flip-flop with the input connected to the center of the device and the output across one junction. All junctions were critically damped to optimize the pulse response. Operation was verified by observing the dc I-V curves of successive SQUIDs driven by a cw pulse train generated on the same chip. Each SQUID exhibited constant-voltage current steps at 1/2 the voltage of the preceding device as expected from the Josephson voltage-to-frequency relation. Steps were observed only for the same voltage polarity of successive devices and for proper phase bias of the SQUID. Binary frequency division was recorded up to 40GHz for devices designed to operate to 28GHz.

  12. 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.......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....

  13. A Multiprocessor Communication Architecture For High Speed Networks

    CERN Document Server

    S, Iyengar; Roy, A A; Sanyal, S; Singhi, N M; Feng, Wu Geng

    2010-01-01

    Over the years, communication speed of networks has increased from a few Kbps to several Mbps, as also the bandwidth demand, Communication Protocols, however have not improved to that extent. With the advent of Wavelength Division Multiplexing (WDM), it is now possible to "tune" protocols to current and future demands. The purpose of this paper is to evolve a High Speed Network architecture, which will cater to the needs of bandwidth-consuming applications, such as voice, video and high definition image transmission.

  14. 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....

  15. Processing speed training increases the efficiency of attentional resource allocation in young adults

    Directory of Open Access Journals (Sweden)

    Wesley K Burge

    2013-10-01

    Full Text Available Cognitive training has been shown to improve performance on a range of tasks. However, the mechanisms underlying these improvements are still unclear. Given the wide range of transfer effects, it is likely that these effects are due to a factor common to a wide range of tasks. One such factor is a participant’s efficiency in allocating limited cognitive resources. The impact of a cognitive training program, Processing Speed Training (PST, on the allocation of resources to a set of visual tasks was measured using pupillometry in 10 young adults as compared to a control group of a 10 young adults (n = 20. PST is a well-studied computerized training program that involves identifying simultaneously presented central and peripheral stimuli. As training progresses, the task becomes increasingly more difficult, by including peripheral distracting stimuli and decreasing the duration of stimulus presentation. Analysis of baseline data confirmed that pupil diameter reflected cognitive effort. After training, participants randomized to PST used fewer attentional resources to perform complex visual tasks as compared to the control group. These pupil diameter data indicated that PST appears to increase the efficiency of attentional resource allocation. Increases in cognitive efficiency have been hypothesized to underlie improvements following experience with action video games, and improved cognitive efficiency has been hypothesized to underlie the benefits of processing speed training in older adults. These data reveal that these training schemes may share a common underlying mechanism of increasing cognitive efficiency in younger adults.

  16. Freeze frame analysis on high speed cinematography of Nd/YAG laser explosions in ocular tissues.

    Science.gov (United States)

    Vernon, S A; Cheng, H

    1986-05-01

    High speed colour cinematography at 400 frames per second was used to photograph both single and train burst Nd/YAG laser applications in ox eyes at threshold energy levels. Measurements of the extent and speed of particle scatter and tissue distortion from the acoustic transient were made from a sequential freeze frame analysis of the films. Particles were observed to travel over 8 mm from the site of Nd/YAG application 20 milliseconds after a single pulse at initial speeds in excess of 20 km/h. The use of train bursts of pulses was seen to increase the number of particles scattered and project the wavefront of particles further from the point of laser application.

  17. 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......, the systems use some form of QPSK modulation and transmit data in frames separated by a sync marker and protected by error-correcting codes. We first give a survey of trends within the area of space modulation systems. We then discuss and define the interfaces and operating modes of the relevant system...... 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...

  18. Flat belt continuously variable high speed drive. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley ``turbine`` (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the ``turbine`` corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the ``turbine`` belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  19. High-speed precision motion control

    CERN Document Server

    Yamaguchi, Takashi; Pang, Chee Khiang

    2011-01-01

    Written for researchers and postgraduate students in Control Engineering, as well as professionals in the Hard Disk Drive industry, this book discusses high-precision and fast servo controls in Hard Disk Drives (HDDs). The editors present a number of control algorithms that enable fast seeking and high precision positioning, and propose problems from commercial products, making the book valuable to researchers in HDDs. Each chapter is self contained, and progresses from concept to technique, present application examples that can be used within automotive, aerospace, aeronautical, and manufactu

  20. High speed multispectral fluorescence lifetime imaging

    NARCIS (Netherlands)

    Fereidouni, F.; Reitsma, K.; Gerritsen, H.C.

    2013-01-01

    We report a spectrally resolved fluorescence lifetime imaging system based on time gated single photon detection with a fixed gate width of 200 ps and 7 spectral channels. Time gated systems can operate at high count rates but usually have large gate widths and sample only part of the fluorescence d

  1. High-speed photography of high-resolution moire patterns

    Science.gov (United States)

    Whitworth, Martin B.; Huntley, Jonathan M.; Field, John E.

    1991-04-01

    The techniques of high resolution moire photography and high speed photography have been combined to allow measurement of the in-plane components of a transient displacement field with microsecond time resolution. Specimen gratings are prepared as casts in a thin layer of epoxy resin on the surface of a specimen. These are illuminated with a flash tube and imaged onto a reference grating with a specially modified camera lens, which incorporates a slotted mask in the aperture plane. For specimen gratings of 75 lines mm1, this selects the +1 and -1 order diffracted beams, thus doubling the effective grating frequency to 150 lines mm1. The resulting real-time moire fringes are recorded with a Hadland 792 image converter camera (Imacon) at an inter-frame time of 2-5ts. The images are digitised and an automatic fringe analysis technique based on the 2-D Fourier transform method is used to extract the displacement information. The technique is illustrated by the results of an investigation into the transient deformation of composite disc specimens, impacted with rectangular metal sliders fired from a gas gun.

  2. Improving acceleration and repeated sprint ability in well-trained adolescent handball players: speed versus sprint interval training.

    Science.gov (United States)

    Buchheit, Martin; Mendez-Villanueva, Alberto; Quod, Marc; Quesnel, Thomas; Ahmaidi, Said

    2010-06-01

    The aim of the current study was to compare the effects of speed/agility (S/A) training with sprint interval training (SIT) on acceleration and repeated sprint ability (RSA) in well-trained male handball players. In addition to their normal training program, players performed either S/A (n = 7) or SIT (n = 7) training for 4 wk. Speed/agility sessions consisted of 3 to 4 series of 4 to 6 exercises (eg, agility drills, standing start and very short sprints, all of Sprint interval training consisted of 3 to 5 repetitions of 30-s all-out shuttle sprints over 40 m, interspersed with 2 min of passive recovery. Pre- and posttests included a countermovement jump (CMJ), 10-m sprint (10m), RSA test and a graded intermittent aerobic test (30-15 Intermittent Fitness Test, V(IFT)). S/A training produced a very likely greater improvement in 10-m sprint (+4.6%, 90% CL 1.2 to 7.8), best (+2.7%, 90% CL 0.1 to 5.2) and mean (+2.2%, 90% CL -0.2 to 4.5) RSA times than SIT (all effect sizes [ES] greater than 0.79). In contrast, SIT resulted in an almost certain greater improvement in V(IFT) compared with S/A (+5.2%, 90% CL 3.5 to 6.9, with ES = -0.83). In well-trained handball players, 4 wk of SIT is likely to have a moderate impact on intermittent endurance capacity only, whereas S/A training is likely to improve acceleration and repeated sprint performance.

  3. Methodology development and integrated control power-speed high-class handball players

    Directory of Open Access Journals (Sweden)

    Josan I.A.

    2014-05-01

    Full Text Available Purpose : based practices and identify effective means of controlling the level of development of power-speed high-class handball players. Material : The study involved 24 women's handball team player of Super League of Ukraine "Dneprjanka" Kherson. Results : methodical conditions defined development speed-strength. Revealed significant changes in terms of the development of power-speed after applying the proposed method of training. Hit run handball throws the ball with 7 meters at best point guards (4.9 ball and welterweight (4.6 ball players, and the lowest at the extremes (4.4 ball and linear (4.4 ball players. Analyzing the accuracy of the shots from a 9-meter mark, found no significant differences between the mean values are not established. Conclusions : Exercise speed-strength of character necessary to carry out the preparatory and in the early part of the basic training. Handball is recommended to use individual tasks to improve the general and special speed-strength training.

  4. Analysis on Correlation between Objective Parameters and Subjective Evaluation of Sound Quality of High Speed Passenger Train%高速铁路客车车内声品质客观参量与主观评价相关性分析

    Institute of Scientific and Technical Information of China (English)

    刘岩; 杨冰; 叶贵鑫; 张常宾; 张晓娟

    2012-01-01

    The HMSm biauricular signal collector of the noise and vibration analysis system was used to extract objective parameters of sound quality including loudness, sharpness, roughness and so on and to carry out objective evaluation. It is concluded that the A-weighting network significantly attenuates the sound pressure level (SPL) of noises in the low frequency range. So noises are underestimated in the low frequency range in high-speed passenger cars. In addition the high frequency components(sharpness)has great influence on subjective feeling of human ears, as a result, even when noises inside high-speed passenger cars satisfy the requirements of A-weighting SPL, the noise transmission mechanism cannot accord with the distribution rule of the sound field, which will cause deviation to vibration and noise reduction design of high-speed passenger trains. The results show as follows: The sharpness of noises inside general carriages of high-speed passenger trains demonstrates an intensifying tendency with raizing of train speeds; but the roughness changes little when train speeds are raized. The study provides reference to design of vibration and noise reduction of highspeed passenger trains.%本文应用噪声与振动分析系统的HMSⅢ双耳信号采集器,提取高速铁路客车响度、尖锐度、粗糙度等声品质客观参量进行客观评价分析研究,得出A计权网络大幅衰减噪声在低频区段的声压级.由于实际中A计权在低频范围的声压级被大幅衰减,以至于高速铁路客车噪声在低频范围内被低估.另外,高频成分比例(尖锐度)同样对人耳主观感受形成较大影响,其结果造成即使高速铁路客车噪声达到A声压级要求,也与噪声实际情况,特别是其传声机理和声场分布规律不相符,给高速铁路客车减振降噪设计带来偏差.研究结果表明:高速铁路客车普通车厢内的尖锐度呈现出随速度提高而增加的趋势;高速铁路客车速度的提

  5. 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...... separated by a sync marker and protected by error-correcting codes. We first give a survey of trends within the area of space modulation systems. We then discuss and define the interfaces and operating modes of the relevant system components. We present a list of system configurations that we find...... 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...

  6. High-speed quantum networking by ship

    Science.gov (United States)

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

    2016-11-01

    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.

  7. 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.

  8. High-speed cineradiography using electronic imaging

    Science.gov (United States)

    Lucero, Jacob P.; Fry, David A.; Gaskill, William E.; Henderson, R. L.; Crawford, Ted R.; Carey, N. E.

    1993-01-01

    The Los Alamos National Laboratory has constructed and is now operating a cineradiography system for imaging and evaluation of ballistic interaction events at the 1200 meter range of the Terminal Effects Research and Analysis (TERA) Group at the New Mexico Institute of Mining and Technology. Cineradiography is part of a complete firing, tracking, and analysis system at the range. The cine system consists of flash x-ray sources illuminating a one-half meter by two meter fast phosphor screen which is viewed by gated-intensified high resolution still video cameras via turning mirrors. The entire system is armored to protect against events containing up to 13.5 kg of high explosive. Digital images are available for immediate display and processing. The system is capable of frame rates up to 105/sec for up to five total images.

  9. High speed cineradiography using electronic imaging

    Science.gov (United States)

    Lucero, J. P.; Fry, D. A.; Gaskill, W. E.; Henderson, R. L.; Crawford, T. R.; Carey, N. E.

    1992-12-01

    The Los Alamos National Laboratory has constructed and is now operating a cineradiography system for imaging and evaluation of ballistic interaction events at the 1200 meter range of the Terminal Effects Research and Analysis (TERA) Group at the New Mexico Institute of Mining and Technology. Cineradiography is part of a complete firing, tracking, and analysis system at the range. The cine system consists of flash x-ray sources illuminating a one-half meter by two meter fast phosphor screen which is viewed by gated-intensified high resolution still video cameras via turning mirrors. The entire system is armored to protect against events containing up to 13.5 kg of high explosive. Digital images are available for immediate display and processing. The system is capable of frame rates up to 10(exp 5)/sec for up to five total images.

  10. High Speed Blood and Transfusion Equipment

    Science.gov (United States)

    2013-10-14

    used to calculate percent hemolysis of red blood cells. Plasma Free Hemoglobin Assay - pRBCs samples were assayed for plasma free hemoglobin (PFH...resulting in high temperatures gradients that preludes blood hemolysis if fluid flow stops. • The solenoid valve has been replaced with a valve of a more...pRBCs to test efficacy. Both pre and post cartridge blood samples were evaluated to determine if any damage may have occurred to blood cells. The

  11. Perfection of badminton players’ speed-power fitness with the help of training means’ variable modules

    Directory of Open Access Journals (Sweden)

    Karatnyk I.V.

    2016-06-01

    Full Text Available Purpose: to determine effectiveness of badminton players’ speed power fitness program’s perfection at stage of specialized basic training with different variants of training means modules’ combination. Material: in experiment badminton players of 15-17 years’ age (from 1st sports grade to master of sports participated. The sportsmen were divided into three experimental groups (10 persons in each. The trainings were being conducted during 24 weeks by different variants of program. Results: we created different complexes of exercises, combined in three modules (every of each lasted eight week micro-cycles. Every module has more expressed meaningful parts (1 - speed, 2 - power, 3 - jumping. All modules were combined in program of badminton players’ speed power fitness perfection. For every experimental group we worked out distinguishing variant of modules’ combination in program (first variant - 1-2-3 modules; second - 2-3-1; third - 3-1-2. General duration of program was 24 week micro-cycles. Conclusions: we recommended some variants of variable modules’ combination for badminton players’ speed-power fitness perfection. With it, we can regard total influence on the following: speed-power endurance, work with support on own body, quick movements of different body links.

  12. A REVIEW OF HIGH-SPEED RAIL PLAN IN JAVA ISLAND: A COMPARISON WITH EXISTING MODES OF TRANSPORT

    Directory of Open Access Journals (Sweden)

    Eko Hartono

    2013-05-01

    It can be concluded that journey time and fare of the high-speed rail is very competitive to the air transport in Jakarta-Surabaya corridor. The journey time to travel from Jakarta to Surabaya is 4 hours and 19 minutes by high-speed train and 4 hours and 40 minutes by air. Based on the benchmarking analysis, the suitable fare for the high-speed rail should be 70% of the air transport. This study predicted that 61% of air passenger, 18% of conventional rail passenger and 12% of bus passenger will switch to the high-speed rail service in 2020. In total, the high-speed rail will have 24% of market share for the passenger transport and becomes the second largest market share after road transport (52%. The conventional rail and air transport have 14% and 9% of total market share to travel from Jakarta to Surabaya and vice versa. The high-speed rail development reduces carbon emissions caused by transportation systems in Java Island. It has been calculated that there are 2.542 million tonnages of CO2 per annum without introducing high-speed rail, however, the CO2 emissions decrease to 1.694 million tonnages per annum if the high-speed rail is developed in Java Island. Generalized cost of the high-speed rail is higher than road and conventional rail. However, it is lower than air transport. Keywords: Java high-speed rail, HSR Comparison, modal share, journey time

  13. In Situ Measurement of Wind-Induced Pulse Response of Sound Barrier Based on High-Speed Imaging Technology

    OpenAIRE

    Chunli Zhu; Jie Guo; Dashan Zhang; Yuan Shen; Dongcai Liu

    2016-01-01

    The lifetime of the sound barrier is threatened by high-speed train-induced impulsive wind pressure as it passes by. The vibration response of the sound barrier during the process of train passing is difficult to be measured using conventional measurement methods because of the inconvenience of the installation of markers on the sound barrier. In this paper, the high-speed camera is used to record the whole process of the train passing by the sound barrier. Then, a displacement extraction alg...

  14. High-speed integrated electroabsorption modulators

    Science.gov (United States)

    Johnson, John E.; Morton, Paul A.; Park, Yong-Kwan; Ketelsen, Leonard J. P.; Grenko, J. A.; Miller, Thomas J.; Sputz, Sharon K.; Tanbun-Ek, Tawee; Vandenberg, J. M.; Yadvish, R. D.; Fullowan, Thomas R.; Sciortino, Paul F., Jr.; Sergent, A. M.; Tsang, Won-Tien

    1997-04-01

    The explosive growth in internet, multimedia and wireless traffic in recent years is rapidly exhausting capacity in public networks worldwide, forcing network service providers to aggressively install new lines and upgrade old ones. Fortunately, technological breakthroughs in the areas of erbium-doped fiber amplifiers (EDFA's), passive wavelength demultiplexers and low chirp sources have made all-optical dense wavelength-division multiplexed (WDM) systems a cost- effective way to utilize the vast bandwidth already available in the embedded fiber plant. WDM systems offer additional operational advantages, including high ultimate capacity, bit-rate transparency, flexible growth strategies, and the potential to use all-optical wavelength routing in future broadband network architectures. Commercial WDM systems operating at the OC-48 (2.5 Gbit/s) line rate are now available, and OC-192 (10 Gbit/s) terminal equipment which is under development will further enhance the capacity of these systems. One of the keys to viable WDM systems is the availability of inexpensive low-chirp optical transmitters. By taking advantage of photonic integrated circuit technology, it is possible to produce monolithically integrated DFB laser/EA modulators (EML's) with low chirp, low drive voltage and high extinction ratio, in a single compact package. In this talk we discuss the operating characteristics of these devices and their relationship to WDM system performance.

  15. Giga bit per second Differential Scheme for High Speed Interconnect

    Directory of Open Access Journals (Sweden)

    Mandeep Singh Narula

    2012-02-01

    Full Text Available The performance of many digital systems today is limited by the interconnection bandwidth between chips. Although the processing performance of a single chip has increased dramatically since the inception of the integrated circuit technology, the communication bandwidth between chips has not enjoyed as much benefit. Most CMOS chips, when communicating off-chip, drive un terminated lines with full-swing CMOS drivers. Such full-swing CMOS interconnect ring-up the line, and hence has a bandwidth that is limited by the length of the line rather than the performance of the semiconductor technology. Thus, as VLSI technology scales, the pin bandwidth does not improve with the technology, but rather remains limited by board and cable geometry, making off-chip bandwidth an even more critical bottleneck. In order to increase the I/O Bandwidth, some efficient high speed signaling standard must be used which considers the line termination, signal integrity, power dissipation, noise immunity etc In this work, a transmitter has been developed for high speed off chip communication. It consists of low speed input buffer, serializer which converts parallel input data into serial data and a current mode driver which converts the voltage mode input signals into current over the transmission line. Output of 32 low speed input buffers is fed to two serializer, each serializer converting 16 bit parallel data into serial data stream. Output of two serializers is fed to LVDS current mode driver. The serial link technique used in this work is the time division multiplex (TDM and point-to-point technique. It means that the low-speed parallel signals are transferred to the high-speed serial signal at the transmitter end and the high-speed serial signal is transferred to the low-speed parallel signals at the receiver end. Serial link is the design of choice in any application where the cost of the communication channel is high and duplicating the links in large numbers is

  16. Giga bit per second Differential Scheme for High Speed Interconnect

    Directory of Open Access Journals (Sweden)

    Mandeep Singh Narula

    2012-03-01

    Full Text Available The performance of many digital systems today is limited by the interconnection bandwidth between chips. Although the processing performance of a single chip has increased dramatically since the inception of the integrated circuit technology, the communication bandwidth between chips has not enjoyed as much benefit. Most CMOS chips, when communicating off-chip, drive unterminated lines with full-swing CMOS drivers. Such full-swing CMOS interconnect ring-up the line, and hence has a bandwidth that is limited by the length of the line rather than the performance of the semiconductor technology. Thus, as VLSI technology scales, the pin bandwidth does not improve with the technology, but rather remains limited by board and cable geometry, making off-chip bandwidth an even more critical bottleneck. In order to increase the I/O Bandwidth, some efficient high speed signaling standard must be used which considers the line termination, signal integrity, power dissipation, noise immunity etc In this work, a transmitter has been developed for high speed offchip communication. It consists of low speed input buffer, serializer which converts parallel input data into serial data and a current mode driver which converts the voltage mode input signals into current over the transmission line. Output of 32 low speed input buffers is fed to two serializer, each serializer converting 16 bit parallel data into serial data stream. Output of two serializers is fed to LVDS current mode driver. The serial link technique used in this work is the time division multiplex (TDM and point-to-point technique. It means that the low-speed parallel signals are transferred to the high-speed serial signal at the transmitter end and the high-speed serial signal is transferred to the low-speed parallel signals at the receiver end. Serial link is the design of choice in any application where the cost of the communication channel is high and duplicating the links in large numbers is

  17. 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, ""

  18. High speed inspection of ceramic fuels

    Energy Technology Data Exchange (ETDEWEB)

    McLemore, D. R.

    1979-03-01

    A fuel pellet inspection system is under development and evaluation for use in the High Performance Fuel Laboratory (HPFL) at Richland, Washington. A major operation in this process is the gaging of fuel pellets for dimensions (length and diameter), surface flaws and weight. The system is modularly designed to simplify maintenance operations thereby reducing personnel exposure. The inspection system is divided into two parts: mechanical and electronic. The mechanical portion consists of a pellet handling system; inspection stations for measuring length, diameter, weight and surface flaws; and a glovebox-like containment which isolates Special Nuclear Material (SNM) from the surrounding environment. The electronic portion is a dedicated minicomputer for process control and a supervisory computer system which will be located in a centralized control center and be shared with other development activities in the HPFL.

  19. The impact of personality on driving safety among Chinese high-speed railway drivers.

    Science.gov (United States)

    Guo, Ming; Wei, Wei; Liao, Ganli; Chu, Fulei

    2016-07-01

    This study explored the impact of personality traits on driving safety in high-speed railway drivers. A sample of high-speed railway drivers in Beijing (N=214) completed a questionnaire, including information on personality traits and background variables. The NEO Five Factor Inventory (NEO-FFI) was administered to characterize participants based on five personality traits: Neuroticism, Extraversion, Agreeableness, Openness to Experience, and Conscientiousness. The survey data were combined with naturalistic data of accident involvement and risky driving behavior in China. Poisson regression results show that drivers with high Conscientiousness and Extraversion caused fewer accidents. Higher Conscientiousness and lower Agreeableness were related to less frequent risky driving behavior. Education level and age negatively moderated the relation between certain personality traits and driving safety. The findings suggest that personality traits should be considered when selecting and training high-speed railway drivers.

  20. Kinematic Operating Modes of Two-Speed Two-Carrier Planetary Gear Trains with Four External Shafts

    OpenAIRE

    Troha, Sanjin; Žigulić, Roberto; Karaivanov, Dimitar

    2014-01-01

    Two-speed planetary gear trains with four external shafts, composed of two simple planetary gear trains, are considered in this paper. The labelling system of these trains is defined and all possible variants are determined. Planetary gear trains are divided into three different design groups, and characteristics of trains of each group are given. Possible power flows through the train at both gears for every group are described. An example of determining the function of transmission ratios o...

  1. Energy Efficiency and Capacity Tradeoff in Cloud Radio Access Network of High-Speed Railways

    OpenAIRE

    Shichao Li; Gang Zhu; Siyu Lin; Qian Gao; Lei Xiong; Weiliang Xie; Xiaoyu Qiao

    2017-01-01

    To meet the increasing demand of high-data-rate services of high-speed railway (HSR) passengers, cloud radio access network (C-RAN) is proposed. This paper investigates the tradeoff between energy efficiency (EE) performance and capacity in C-RAN of HSR. Considering that the train location can be predicted, we propose a predictable path loss based time domain power allocation method (PPTPA) to improve EE performance of HSR communication system. First, we consider that the communication system...

  2. Effect of preseason concurrent muscular strength and high-intensity interval training in professional soccer players.

    Science.gov (United States)

    Wong, Pui-lam; Chaouachi, Anis; Chamari, Karim; Dellal, Alexandre; Wisloff, Ulrik

    2010-03-01

    This study examined the effect of concurrent muscular strength and high-intensity running interval training on professional soccer players' explosive performances and aerobic endurance. Thirty-nine players participated in the study, where both the experimental group (EG, n = 20) and control group (CG, n = 19) participated in 8 weeks of regular soccer training, with the EG receiving additional muscular strength and high-intensity interval training twice per week throughout. Muscular strength training consisted of 4 sets of 6RM (repetition maximum) of high-pull, jump squat, bench press, back half squat, and chin-up exercises. The high-intensity interval training consisted of 16 intervals each of 15-second sprints at 120% of individual maximal aerobic speed interspersed with 15 seconds of rest. EG significantly increased (p aerobic speed test, and maximal aerobic speed. High-intensity interval running can be concurrently performed with high load muscular strength training to enhance soccer players' explosive performances and aerobic endurance.

  3. 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.

  4. SPH simulations of high-speed collisions

    Science.gov (United States)

    Rozehnal, Jakub; Broz, Miroslav

    2016-10-01

    Our work is devoted to a comparison of: i) asteroid-asteroid collisions occurring at lower velocities (about 5 km/s in the Main Belt), and ii) mutual collisions of asteroids and cometary nuclei usually occurring at significantly higher relative velocities (> 10 km/s).We focus on differences in the propagation of the shock wave, ejection of the fragments and possible differences in the resultingsize-frequency distributions of synthetic asteroid families. We also discuss scaling with respect to the "nominal" target diameter D = 100 km, projectile velocity 3-7 km/s, for which a number of simulations were done so far (Durda et al. 2007, Benavidez et al. 2012).In the latter case of asteroid-comet collisions, we simulate the impacts of brittle or pre-damaged impactors onto solid monolithic targets at high velocities, ranging from 10 to 15 km/s. The purpose of this numerical experiment is to better understand impact processes shaping the early Solar System, namely the primordial asteroid belt during during the (late) heavy bombardment (as a continuation of Broz et al. 2013).For all hydrodynamical simulations we use a smoothed-particle hydrodynamics method (SPH), namely the lagrangian SPH3D code (Benz & Asphaug 1994, 1995). The gravitational interactions between fragments (re-accumulation) is simulated with the Pkdgrav tree-code (Richardson et al. 2000).

  5. 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...

  6. Low Speed and High Speed Correlation of SMART Active Flap Rotor Loads

    Science.gov (United States)

    Kottapalli, Sesi B. R.

    2010-01-01

    Measured, open loop and closed loop data from the SMART rotor test in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with CAMRAD II calculations. One open loop high-speed case and four closed loop cases are considered. The closed loop cases include three high-speed cases and one low-speed case. Two of these high-speed cases include a 2 deg flap deflection at 5P case and a test maximum-airspeed case. This study follows a recent, open loop correlation effort that used a simple correction factor for the airfoil pitching moment Mach number. Compared to the earlier effort, the current open loop study considers more fundamental corrections based on advancing blade aerodynamic conditions. The airfoil tables themselves have been studied. Selected modifications to the HH-06 section flap airfoil pitching moment table are implemented. For the closed loop condition, the effect of the flap actuator is modeled by increased flap hinge stiffness. Overall, the open loop correlation is reasonable, thus confirming the basic correctness of the current semi-empirical modifications; the closed loop correlation is also reasonable considering that the current flap model is a first generation model. Detailed correlation results are given in the paper.

  7. Quality of service on high-speed data networks

    Science.gov (United States)

    Barbero, Ezio; Antonelli, Ferruccio

    1995-02-01

    Since the beginning of this century the issue of `quality' has been gaining increasing importance in a number of fields of human activities. For telecommunication services, too, the quality perceived by customers has been taken into account early on as an issue of strategic importance. Whilst for telephony the Quality of Service (QoS) has been already investigated and identified in terms of parameters and related test methodology, the situation for high speed data services (i.e. CBDS/SMDS, Frame Relay, etc.), provided by means of high speed network based on Asynchronous Transfer Moe (ATM) or Metropolitan Area Network technologies, can still be considered `under study'. There is a death of experience not only in terms of measurement instruments and procedures, but also in terms of knowledge of the relationship between the QoS provided at a network level and the quality perceived by the user on his or her terminal. The complexity of the equipment involved in setting up an end-to-end solution based on high speed data communications makes the problems of knowledge and supply of quality very hard to solve. Starting from the experience gained in carrying out high- speed network field trials based on Metropolitan Area Networks and, more recently, on ATM technology, the paper mainly deals with the problem of defining, measuring and then offering a specific QoS. First, the issue of what the user expects from the `high-speed network' is addressed. This analysis is carried out trying to gather what is peculiar to high-speed data communications from the user standpoint. Next, the focus is on how to cope with the requirements due to users' expectations, while carefully considering the basic principles of quality. Finally, a solution is proposed, starting from the experience gained from high speed networks installed in Italy.

  8. FEATURES OF PERCEPTION OF LOADING ELEMENTS OF THE RAILWAY TRACK AT HIGH SPEEDS OF THE MOVEMENT

    Directory of Open Access Journals (Sweden)

    D. M. Kurhan

    2015-03-01

    Full Text Available Purpose. Increase the train speeds movements requires not only the appropriate technical solutions, but also methodological-calculated. Most of the models and methodologies used for solving problems of stress-strain state of the railroad tracks, are based on assumptions and hypotheses adequate only for certain speeds. In the framework of this work will be discussed theoretical background of the changing nature of perceptual load elements of the railway track at high speeds and investigated the numeric parameters of the processes by means of mathematical modeling. As a practical purposes is expected to provide the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Methodology. To achieve these objectives was used principal new model of railway track based on wave propagation theory stresses in the elastic system to study the impact of the movable load, take into account that the deflection in a particular section of the road starts even while the wheels at some distance, and moving the wheels farther from the selected section of the wave front elastic strain continues to spread. According to the results of simulations explores the changing shape of the wave front voltages in time for the foundation under the rail. If the train speeds substantially less than the velocity propagation of elastic waves, the wheel remains in the area implemented deformations. Findings. Alternative calculations for various parameters of the railway track (especially for different soil conditions determined the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Originality. The proposed theoretical study and implementation in the form of mathematical models for processes that occur in the perception of load elements of the railway track at high speeds. Practical value. According to simulation results obtained levels of

  9. Recent progress on high-speed optical transmission

    Directory of Open Access Journals (Sweden)

    Jianjun Yu

    2016-05-01

    Full Text Available The recently reported high spectral efficiency (SE and high-baud-rate signal transmission are all based on digital coherent optical communications and digital signal processing (DSP. DSP simplifies the reception of advanced modulation formats and also enables the major electrical and optical impairments to be processed and compensated in the digital domain, at the transmitter or receiver side. In this paper, we summarize the research progress on high-speed signal generation and detection and also show the progress on DSP for high-speed signal detection. We also report the latest progress on multi-core and multi-mode multiplexing.

  10. Ultra-high-speed spectropolarimeter based on photoelastic modulator.

    Science.gov (United States)

    Zhang, Rui; Li, Kewu; Chen, Yuanyuan; Wen, Tingdun; Zhang, Minjuan; Wang, Yaoli; Xue, Peng; Wang, Zhibin

    2016-10-20

    Combined with the advantages of photoelastic modulator (PEM) ultra-high-speed modulation, this paper presents a method of ultra-high-speed spectropolarimeter based on PEM. The method provides the necessary measuring instruments for ultra-high-speed polarization spectroscopy. The main idea of this method is that an intensity modulator consisting of two retarders is placed before the PEM. The incident light under test goes through two retarders to the PEM. The interference signals are obtained by the PEM modulation. The different Stokes element interference signals are modulated by the PEM at different positions of the optical path difference. This method realizes the separation of Stokes element interference signals. The interference signals corresponding to each element are extracted, and the incident light Stokes element spectra can be obtained from the Fourier transforms of the interference signals. The modulation frequency of the PEM is high (tens to hundreds of kilohertz), so this method can realize ultra-high-speed full polarization spectroscopy. A prototype ultra-high-speed spectropolarimeter based on PEM was designed and tested. If the single-sided Fourier transformation is used, the single-sided interferogram scanning time is approximately 5 μs (i.e., the prototype is capable of scanning 20,000 interferograms per second). Polychromatic light polarization spectroscopy is measured by the prototype. The experimental results show that the average error of the prototype is less than 0.03.

  11. High speed twin roll caste for aluminum alloy thin strip

    Directory of Open Access Journals (Sweden)

    T. Haga

    2007-09-01

    Full Text Available Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated.Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metalography, a tension test, and a bending test.Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. A casting nozzle was used to set the solidification length precisely. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed and high-cooling rate twin roll caster of the present study for recycling aluminum alloy was investigated. Fe was added as impurity to 6063 and A356. The roll caster of the present study was useful to decrease the influence of impurity of Fe.Research limitations/implications: A high-speed twin roll caster of vertical type was designed and assembled to cast aluminum alloy thin strip.Originality/value: The results demonstrate that the high-speed twin roll caster can improve the deterioration by impurities.

  12. Brain training game improves executive functions and processing speed in the elderly: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Rui Nouchi

    Full Text Available BACKGROUND: The beneficial effects of brain training games are expected to transfer to other cognitive functions, but these beneficial effects are poorly understood. Here we investigate the impact of the brain training game (Brain Age on cognitive functions in the elderly. METHODS AND RESULTS: Thirty-two elderly volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris. This study was completed by 14 of the 16 members in the Brain Age group and 14 of the 16 members in the Tetris group. To maximize the benefit of the interventions, all participants were non-gamers who reported playing less than one hour of video games per week over the past 2 years. Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Each group played for a total of about 20 days. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into four categories (global cognitive status, executive functions, attention, and processing speed. Results showed that the effects of the brain training game were transferred to executive functions and to processing speed. However, the brain training game showed no transfer effect on any global cognitive status nor attention. CONCLUSIONS: Our results showed that playing Brain Age for 4 weeks could lead to improve cognitive functions (executive functions and processing speed in the elderly. This result indicated that there is a possibility which the elderly could improve executive functions and processing speed in short term training. The results need replication in large samples. Long-term effects and relevance for every-day functioning remain uncertain as yet. TRIAL REGISTRATION: UMIN Clinical Trial Registry 000002825.

  13. 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.

  14. Review of actuators for high speed active flow control

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; LUO ZhenBing; XIA ZhiXun; LIU Bing; DENG Xiong

    2012-01-01

    Actuators are one of the key points for the development of active flow control technology.Efficient methods of high speed flow control can provide enhanced propulsive efficiency and at the same time enable safe and maneuverable high speed flight.The development of high speed flight technology promotes the emergence of novel and robust actuators.This review introduces the state of the art in the development of actuators that can be used in high speed active flow control.The classification and different operation criteria of the actuators are discussed.The specifications,mechanisms and applications of various popular actuator types including fluidic,mechanical,and plasma actuators are described.Based on the realistic need of high speed flow control and the existing results of actuators,a new actuator design method is proposed.At last,the merits and drawbacks of the actuators are summarized and some suggestions on the development of active flow control technology are put forward.

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

    DEFF Research Database (Denmark)

    Li, Hailing; Wu, Haiyan; Lou, Lei

    2012-01-01

    , 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......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...

  16. Influence of Bridge Structure Stiffness on the Dynamic Performance of High-Speed Train-Track-Bridge Coupled System%桥梁结构刚度对高速列车—轨道—桥梁耦合系统动力特性的影响

    Institute of Scientific and Technical Information of China (English)

    翟婉明; 王少林

    2012-01-01

    The dynamic performances of high-speed train-track bridge coupled system are significantly affected by the structure stiffness of bridge, which directly influences the running safety and ride comfort of a train on the bridge. Based on train-track-bridge dynamic interaction theory, the influences of structure stiffness of bridge on the dynamic responses of the coupled system were analyzed using the train-track-bridge dynamic simulation software TTBSIM2. 0, in which a simply supported bridge and double-block ballastless track both commonly used in high-speed railway were chosen to be the study object. Results show that when the stiffness of beam or the lateral stiffness of piers is insufficient, the major dynamic indexes of train and bridge increase dramatically with the decrease of the stiffness, and the running safety and the ride comfort of the train are deteriorated severely. In particular, the resonance of beam excited by passing train may occur if the vertical stiffness of beam is insufficient. When the structure stiffness of bridge satisfies the design code, the dynamic responses of train-bridge system vary little with the change of stiffness. The running speed and track irregularities become the main factors to influence the running safety and ride comfort of train.%桥梁结构刚度对高速列车—轨道—桥梁耦合系统的动力学特性具有重要的影响,直接关系到桥上列车的行车安全性和运行平稳性.基于列车—轨道—桥梁动力相互作用理论,以高速铁路常用的简支箱梁桥和双块式无砟轨道为研究对象,采用列车—轨道—桥梁动力学仿真通用软件TTBSIM2.0,研究桥梁结构刚度对高速列车—轨道—桥梁耦合系统动力性能的影响规律.结果表明:当桥梁梁体的刚度或者桥墩的横向刚度不足时,车辆和桥梁的相关动力性能指标将随着刚度的减少而急剧增大,严重影响列车过桥时的安全性和平稳性;当梁体垂向刚度不足

  17. High-speed running performance: a new approach to assessment and prediction.

    Science.gov (United States)

    Bundle, Matthew W; Hoyt, Reed W; Weyand, Peter G

    2003-11-01

    We hypothesized that all-out running speeds for efforts lasting from a few seconds to several minutes could be accurately predicted from two measurements: the maximum respective speeds supported by the anaerobic and aerobic powers of the runner. To evaluate our hypothesis, we recruited seven competitive runners of different event specialties and tested them during treadmill and overground running on level surfaces. The maximum speed supported by anaerobic power was determined from the fastest speed that subjects could attain for a burst of eight steps (approximately 3 s or less). The maximum speed supported by aerobic power, or the velocity at maximal oxygen uptake, was determined from a progressive, discontinuous treadmill test to failure. All-out running speeds for trials of 3-240 s were measured during 10-13 constant-speed treadmill runs to failure and 4 track runs at specified distances. Measured values of the maximum speeds supported by anaerobic and aerobic power, in conjunction with an exponential constant, allowed us to predict the speeds of all-out treadmill trials to within an average of 2.5% (R2 = 0.94; n = 84) and track trials to within 3.4% (R2 = 0.86; n = 28). An algorithm using this exponent and only two of the all-out treadmill runs to predict the remaining treadmill trials was nearly as accurate (average = 3.7%; R2 = 0.93; n = 77). We conclude that our technique 1) provides accurate predictions of high-speed running performance in trained runners and 2) offers a performance assessment alternative to existing tests of anaerobic power and capacity.

  18. MARVIN : high speed 3D imaging for seedling classification

    NARCIS (Netherlands)

    Koenderink, N.J.J.P.; Wigham, M.L.I.; Golbach, F.B.T.F.; Otten, G.W.; Gerlich, R.J.H.; Zedde, van de H.J.

    2009-01-01

    The next generation of automated sorting machines for seedlings demands 3D models of the plants to be made at high speed and with high accuracy. In our system the 3D plant model is created based on the information of 24 RGB cameras. Our contribution is an image acquisition technique based on

  19. Impact of the vibrations on the environment caused by passages of trains at variable speed

    Directory of Open Access Journals (Sweden)

    Kożuch Barbara

    2016-01-01

    Full Text Available The paper deals with negative environmental impact caused by the passages of different kinds of trains at variable speed. The study is based on the measurement results which took place in Poland in 2013 on the railway line no. 4. The effect of the traction unit – Pendolino (EMU 250 on the vibration climate was analysed. The impact of passages of new trains was compared to currently operated rolling stock. The speed of trains was varying between 40 and 250 km/h. Vibration measurements were conducted by stuff of an accredited Laboratory of Structural Mechanics at Cracow University of Technology (Accreditation No. AB 826. The influence of the indicated vibrations due to passages of the trains on the building in the neighbourhood of the line was investigated. The vibration assessment was done for horizontal components of vibrations according to Polish standard code. Assessment of environmental impact was presented by indicator of perceptibility of vibration through construction (WODB, which refers to the Scales of Dynamic Influences (SDI scales. The limits specified by standards in any of the passages have not been exceeded. The change of speed or rolling stock resulted in a change in the characteristic of the vibration spectrum.

  20. A Fuzzy Optimization Model for High-Speed Railway Timetable Rescheduling

    Directory of Open Access Journals (Sweden)

    Li Wang

    2012-01-01

    Full Text Available A fuzzy optimization model based on improved symmetric tolerance approach is introduced, which allows for rescheduling high-speed railway timetable under unexpected interferences. The model nests different parameters of the soft constraints with uncertainty margin to describe their importance to the optimization purpose and treats the objective in the same manner. Thus a new optimal instrument is expected to achieve a new timetable subject to little slack of constraints. The section between Nanjing and Shanghai, which is the busiest, of Beijing-Shanghai high-speed rail line in China is used as the simulated measurement. The fuzzy optimization model provides an accurate approximation on train running time and headway time, and hence the results suggest that the number of seriously impacted trains and total delay time can be reduced significantly subject to little cost and risk.

  1. VCA Direct-Drive High Speed and Precision XY Table

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xingyu; FENG Xiaomei; ZHANG Dawei

    2007-01-01

    In order to compensate for the limitation of conventional XY table used in semiconductor integrated circuits(IC) packaging and improve its speed and accuracy, a voice coil actuator (VCA)direct-drive high-speed and precision positioning XY table used in wire bonder was proposed. Also, a novel flexible decoupling mechanism was used in the positioning table, and the small moving mass enabled the positioning table to move at high speed and precision. XY table deformation interference caused by assembly error and instant interference generated by dynamic load moving with high speed and acceleration can be eliminated through the flexible decoupling mechanism. Considering the positioning table as lumped mass spring system, the dynamic equations of the mechanical sys-tem and the VCA were built according to the Newton mechanics principle and electromagnetic theory. Then the electromechanical coupling control model of the system was created through Laplace transform. Based on displacement PID controller, the Icop-locked controlling algorithm of the positioning system was investigated. The dynamic control algorithm effectively improved the system dynamic performance. The precision test of the prototype machine was carried out, and the results val-idated the correctness of the model and the theory. Compared with traditional XY table, the tablehas higher speed, acceleration and positioning accuracy.

  2. 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.

  3. High Speed, Low Power Current Comparators with Hysteresis

    Directory of Open Access Journals (Sweden)

    Neeraj K. Chasta

    2012-02-01

    Full Text Available This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis, where comparator gives high accuracy (less than 50nA and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180 nm CMOS process technology for a supply voltage of 3V.

  4. High Speed, Low Power Current Comparators with Hysteresis

    Directory of Open Access Journals (Sweden)

    Neeraj K. Chasta

    2012-03-01

    Full Text Available This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis, where comparator gives high accuracy (less than 50nA and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180nm CMOS process technology for a supply voltage of 3V.

  5. 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....

  6. Necking Point in PET High-speed Fiber Spinning

    Institute of Scientific and Technical Information of China (English)

    王夏琴; 唐志廉

    2001-01-01

    Cross-over method is established to predict necking point for PET high- speed fiber spinning. Even slowly crystallizing polymers such as PET can crystallize on the spinline at sufficiently high spinning speed. The development of rtmning velocity, temperature, crystallinity and theological force is investigated for the take-up velocity over a range of 6 000 - 10 000 m/min. The position of necking point, temperature rise and abrupt increase of crystallinity move closer to the spinneret with the increase of take-up velocity,

  7. High Speed, Low Power Current Comparators with Hysteresis

    CERN Document Server

    Chasta, Neeraj K

    2012-01-01

    This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis), where comparator gives high accuracy (less than 50nA) and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180nm CMOS process technology for a supply voltage of 3V.

  8. 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.

  9. Improvement of die life in high speed injection die casting

    Institute of Scientific and Technical Information of China (English)

    Yasuhiro Arisuda; Akihito Hasuno; Junji Yoshida; Kazunari Tanii

    2008-01-01

    High-speed injection die casting is an efficient manufacturing technology for upgrading aluminum die-cast products. However, deficiencies (such as die damage in eady period) due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die temperature analysis, flow analysis and thermal stress analysis). The potential countermeasures to solve the above problems were also proposed.

  10. Improvement of die life in high speed injection die casting

    Directory of Open Access Journals (Sweden)

    Akihito Hasuno

    2008-11-01

    Full Text Available High-speed injection die casting is an effi cient manufacturing technology for upgrading aluminum die-cast products. However, defi ciencies (such as die damage in early period due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die emperature analysis, fl ow analysis and thermal stress analysis. The potential countermeasures to solve the above problems were also proposed.

  11. Compact Models and Measurement Techniques for High-Speed Interconnects

    CERN Document Server

    Sharma, Rohit

    2012-01-01

    Compact Models and Measurement Techniques for High-Speed Interconnects provides detailed analysis of issues related to high-speed interconnects from the perspective of modeling approaches and measurement techniques. Particular focus is laid on the unified approach (variational method combined with the transverse transmission line technique) to develop efficient compact models for planar interconnects. This book will give a qualitative summary of the various reported modeling techniques and approaches and will help researchers and graduate students with deeper insights into interconnect models in particular and interconnect in general. Time domain and frequency domain measurement techniques and simulation methodology are also explained in this book.

  12. Magneto-optical system for high speed real time imaging

    Science.gov (United States)

    Baziljevich, M.; Barness, D.; Sinvani, M.; Perel, E.; Shaulov, A.; Yeshurun, Y.

    2012-08-01

    A new magneto-optical system has been developed to expand the range of high speed real time magneto-optical imaging. A special source for the external magnetic field has also been designed, using a pump solenoid to rapidly excite the field coil. Together with careful modifications of the cryostat, to reduce eddy currents, ramping rates reaching 3000 T/s have been achieved. Using a powerful laser as the light source, a custom designed optical assembly, and a high speed digital camera, real time imaging rates up to 30 000 frames per seconds have been demonstrated.

  13. Microstructural development and mechanical properties of high speed steels

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, A.; Gordo, E.; Velasco, F.; Candela, N.; Torralba, J.M. [Dept. de Ciencia de Materiales e Ing. Metalurgica, Univ. Carlos III de Madrid (Spain)

    2001-07-01

    A study was made of the sintering of high speed steel (HSS), M3/2, with different percentage additions - (0%, 2.5%, 5% and 8% by vol.) - of niobium carbide. The mixture was ground in a high speed ball mill to ensure smooth distribution and a material free from agglomerates. All the mixtures were sintered at temperatures above that of solidus, higher temperatures being required as the proportion of the niobium carbide was increased. The variation of the density and hardness were measured, as well as the evolution of the microstructure and the composition of the carbides with the sintering temperature. (orig.)

  14. Plasma-Assisted Chemistry in High-Speed Flow

    Institute of Scientific and Technical Information of China (English)

    Sergey B.LEONOV; Dmitry A.YARANTSEV; Anatoly P.NAPARTOVICH; Igor V.KOCHETOV

    2007-01-01

    Fundamental problems related to the high-speed combustion are analyzed. The result of plasma-chemical modeling is presented as a motivation of experimental activity.Numerical simulations of the effect of uniform non-equilibrium discharge on the premixed hydrogen and ethylene-air mixture in supersonic flow demonstrate an advantage of such a technique over a heating.Experimental results on multi-electrode non-uniform discharge maintenance behind wallstep and in cavity of supersonic flow are presented.The model test on hydrogen and ethylene ignition is demonstrated at direct fuel injection to low-temperature high-speed airflow.

  15. Efficient Method for Improving the Reliability of Decentralized Operation Control System of High-speed Maglev Train%高速磁浮列车分区运行控制系统可靠性提高方法研究

    Institute of Scientific and Technical Information of China (English)

    周鹏; 徐洪泽

    2011-01-01

    The decentralized operation control system is a kind of safety-critical computer control system, which realizes the function of operation command and safety protection for high-speed maglev trains. On the basis of the experience of developing, debugging and running the engineering prototype of the decentralized operation control system on the 1. 5km high-speed maglev experimental railway line, the status collection model was set up. Based on the model, an efficient method for improving reliability was proposed. The feasibility of the method was proved. At last, the method was applied in the decentralized operation control system, and the reliability of the high-speed maglev train operation control system was improved efficiently, which is useful to nationalize the high-speed maglev decentralized operation control system.%分区运行控制系统是实现高速磁浮列车运行指挥及安全防护的安全苛求计算机控制系统.本文借鉴上海同济大学1.5km高速磁浮列车试验线的分区运行控制系统工程样机研制与现场运行调试经验,建立状态回采模型.基于该模型提出一套适用于高速磁浮列车分区运行控制系统软件的可靠性提高方法:状态回采法,并从理论上证明了这种方法的可行性,最终将该方法运用于分区运行控制系统,提高了其可靠性,为高速磁浮列车分区控制系统的国产化工作提供了技术支持.

  16. High-speed wavefront modulation in complex media (Conference Presentation)

    Science.gov (United States)

    Turtaev, Sergey; Leite, Ivo T.; Cizmár, TomáÅ.¡

    2017-02-01

    Using spatial light modulators(SLM) to control light propagation through scattering media is a critical topic for various applications in biomedical imaging, optical micromanipulation, and fibre endoscopy. Having limited switching rate, typically 10-100Hz, current liquid-crystal SLM can no longer meet the growing demands of high-speed imaging. A new way based on binary-amplitude holography implemented on digital micromirror devices(DMD) has been introduced recently, allowing to reach refreshing rates of 30kHz. Here, we summarise the advantages and limitations in speed, efficiency, scattering noise, and pixel cross-talk for each device in ballistic and diffusive regimes, paving the way for high-speed imaging through multimode fibres.

  17. 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.

  18. TCP-Adaptive in High Speed Long Distance Networks

    Directory of Open Access Journals (Sweden)

    Quan Liu

    2014-02-01

    Full Text Available With the development of high performance computing and increasing of network bandwidth, more and more applications require fast data transfer over high-speed long-distance networks. Research shows that the standard TCP Reno cannot fulfill the requirement of fast transfer of massive data due to its conservative congestion control mechanism. Some works have been proposed to improve the TCP throughput performance using more aggressive window increasing tactics and obtain substantial achievements. However, they cannot be strictly proved to be comprehensively suitable for high-speed complex network environments. In this paper, we propose TCP-Adaptive, an adaptive congestion control algorithm adjusting the increasing congestion window dynamically. The algorithm improves logarithmic detection procedure for available bandwidth in the flow path by distinguishing the first detection in congestion avoidance and retransmission timeout. On the other hand, an adaptive control algorithm is proposed to achieve better performance in high-speed long-distance networks. The algorithm uses round trip time (RTT variations to predict the congestion trends to update the increments of congestion window. Simulations verify the property of TCP-Adaptive and show satisfying performance in throughput, RTT fairness aspects over high-speed long-distance networks. Especially in sporadic loss environment, TCP-Adaptive shows a significant adaptability with the variations of link quality

  19. High-speed traveling-wave electro-absorption modulators

    Science.gov (United States)

    Westergren, Urban; Yu, Yichuan; Thylén, Lars

    2006-07-01

    Electroabsorption modulators (EAM) based on quantum-confined Stark effect (QCSE) in multiplequantum wells (MQW) have been demonstrated to provide high-speed, low drive voltage, and high extinction ratio. They are compact in size and can be monolithically integrated with continuous-wave (CW) lasers. In order to achieve both high speed and low drive-voltage operation, travelling-wave (TW) electrode structures can be used for EAMs. The inherently low impedance of high-speed EAMs may be transformed to values close to the standard 50Ohm impedance using periodic microwave structures with a combination of passive transmission lines with high characteristic impedance and active modulator sections with low impedance. Modulation bandwidths of 100GHz (-3dBe) have been accomplished with electrical reflections lower than -10dB in a 50Ohm system. Transmission at 80Gbit/s with non-return-to-zero (NRZ) code has been demonstrated for InP-based TWEAMs using electronic time-domain multiplexing (ETDM), indicating the possibility of reaching speeds of 100Gbit/s and beyond.

  20. 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.