WorldWideScience

Sample records for high speed analysis

  1. 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.

  2. Thermal analysis of high speed permanent magnetic generator

    Institute of Scientific and Technical Information of China (English)

    LI WeiLi; ZHANG XiaoChen; CHENG ShuKang; CAO JunCi; ZHANG YiHuang

    2012-01-01

    High-speed permanent magnetic generators (HSPMG) are common and important power generation equipments used in distributed generation systems.A 100 kW level HSPMG is investigated in this paper,and it is fluid-thermal coupling analyzed.The transient 2D electromagnetic field while machine is under rated operating is analyzed by using the time-stepping FEM,from which the electromagnetic performances and the loss distributions are obtained.Then,an analysis model for fluid-solid temperature field analysis is established.Taking losses as the distributed heat sources,the 3D thermal field is coupling calculated.The variations of heat transfer coefficient and temperature of fluid in stator grooves along the axial direction,as well as the whole region 3D temperature distribution in HSPMG are obtained.Then,considering the variations of heat sources distributions and heat transfer conditions,3D temperature fields of HSPMG operating under different speeds are calculated,and the influences of machine operating speed on the HSPMG thermal performance are studied,based on which,the functions of machine temperature with operating speed and stator windings resistance are proposed.The obtained conclusions may provide a useful reference for the design and research of HSPMG.

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

    OpenAIRE

    Simarpreet Singh Chawla; Swapnil Aggarwal; Anshika; Nidhi Goel

    2015-01-01

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

  4. 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...

  5. Tool Failure Analysis in High Speed Milling of Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiuxu; MEYER Kevin; HE Rui; YU Cindy; NI Jun

    2006-01-01

    In high speed milling of titanium alloys the high rate of tool failure is the main reason for its high manufacturing cost. In this study, fractured tools which were used in a titanium alloys 5-axis milling process have been observed both in the macro scale using a PG-1000 light microscope and in the micro scale using a Scanning Electron Microscope (SEM) respectively. These observations indicate that most of these tool fractures are the result of tool chipping. Further analysis of each chipping event has shown that beachmarks emanate from points on the cutting edge. This visual evidence indicates that the cutting edge is failing in fatigue due to cyclical mechanical and/or thermal stresses. Initial analyses explaining some of the outlying conditions for this phenomenon are discussed. Future analysis regarding determining the underlying causes of the fatigue phenomenon is then outlined.

  6. New technique for high-speed microjet breakup analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vago, N. [Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest (Hungary); Synova SA, Ch. Dent d' Oche, 1024 Ecublens (Switzerland); Spiegel, A. [Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest (Hungary); Couty, P. [Institute of Imaging and Applied Optics, Swiss Federal Institute of Technology, Lausanne, BM, 1015, Lausanne (Switzerland); Wagner, F.R.; Richerzhagen, B. [Synova SA, Ch. Dent d' Oche, 1024 Ecublens (Switzerland)

    2003-10-01

    In this paper we introduce a new technique for visualizing the breakup of thin high-speed liquid jets. Focused light of a He-Ne laser is coupled into a water jet, which behaves as a cylindrical waveguide until the point where the amplitude of surface waves is large enough to scatter out the light from the jet. Observing the jet from a direction perpendicular to its axis, the light that appears indicates the location of breakup. Real-time examination and also statistical analysis of the jet disruption is possible with this method. A ray tracing method was developed to demonstrate the light scattering process. (orig.)

  7. Optimization and Performance Analysis of High Speed Mobile Access Networks

    CERN Document Server

    Weerawardane, Thushara

    2012-01-01

    The design and development of cost-effective mobile broadband wireless access networks is a key challenge for many mobile network operators. The over-dimensioning or under-dimensioning of an access network results in both additional costs and customer dissatisfaction.   Thushara Weerawardane introduces new transport technologies and features for High Speed Packet Access (HSPA) and Long-Term Evolution (LTE) networks. Using advanced scientific methods, he proposes new adaptive flow control and enhanced congestion control algorithms, then defends them with highly-developed analytical models derived from Markov chains. For faster analysis, compared to long-lasting detailed simulations, these models provide optimum network performance and ensure reliable quality standards for end users during transport network congestion. Further, the author investigates and analyzes LTE transport network performance by introducing novel traffic differentiation models and buffer management techniques during intra-LTE handovers.

  8. 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.

  9. Specification and analysis of a high speed transport protocol

    Science.gov (United States)

    Tipici, Huseyin A.

    1993-06-01

    While networks have been getting faster, perceived throughput at the application has not always increased accordingly and the bottleneck has moved to the communications processing part of the system. The issues that cause the performance bottlenecks in the current transport protocols are discussed in this thesis, and a further study on a high speed transport protocol which tries to overcome these difficulties with some unique features is presented. By using the Systems of Communicating Machines (SCM) model as a framework, a refined and improved version of the formal protocol specification is built over the previous work, and it is analyzed to verify that the protocol is free from logical errors such as deadlock, unspecified reception, unexecuted transitions and blocking loops. The analysis is conducted in two phases which consists of the application of the associated system state analysis and the simulation of the protocol using the programming language ADA. The thesis also presents the difficulties encountered during the course of the analysis, and suggests possible solutions to some of the problems.

  10. Analysis of OFDM Applied to Powerline High Speed Digital Communication

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Jian; YANG Gong-xu

    2003-01-01

    The low voltage powerline is becoming a powerful solution to home network, building automation, and internet access as a result of its wide distribution, easy access and little maintenance. The character of powerline channel is very complicated because it is an open net. This article analysed the character of the powerline channel,introduced the basics of OFDM(Orthogonal Frequency Division Multiplexing), and studied the OFDM applied into powerline high speed digital communication.

  11. Advanced waveform decomposition for high-speed videoendoscopy analysis.

    Science.gov (United States)

    Ikuma, Takeshi; Kunduk, Melda; McWhorter, Andrew J

    2013-05-01

    This article presents a novel approach to analyze nonperiodic vocal fold behavior of high-speed videoendoscopy (HSV) data. Although HSV can capture true vibrational motions of the vocal folds, its clinical advantage over the videostroboscopy has not widely been accepted. One of the key advantages of the HSV over the videostroboscopy is its ability to capture vocal folds' nonperiodic behavior, which is more prominent in pathological vocal folds. However, such nonperiodicity in the HSV data has not been fully explored quantitatively beyond simple perturbation analysis. This article presents an advanced waveform modeling and decomposition technique for HSV-based waveforms. Waveforms are modeled to have three components: harmonic signal, deterministic nonharmonic signal, and random nonharmonic signal. This decomposition is motivated by the fact that voice disorders introduce signal content that is nonharmonic but carries deterministic quality such as subharmonic or modulating content. The proposed model is aimed to isolate such disordered behaviors as deterministic nonharmonic signal and quantify them. In addition to the model, the article outlines model parameter estimation procedures and a family of harmonics-to-noise ratio (HNR) parameters. The proposed HNR parameters include harmonics-to-deterministic-noise ratio (HDNR) and harmonics-to-random-noise ratio. A preliminary study demonstrates the effectiveness of the extended model and its HNR parameters. Vocal folds with and without benign lesions (Nwith = 13; Nwithout = 20) were studied with HSV glottal area waveforms. All three HNR parameters significantly distinguished the disordered condition, and the HDNR reported the largest effect size (Cohen's d = 2.04).

  12. Flow Analysis By High Speed Photography And Pictures

    Science.gov (United States)

    Werle, H.

    1985-02-01

    At the ONERA hydrodynamic visualization laboratory, high-speed photography and cinematography are used for analysing flow-phenomena around fixed or mobile models in the test section of three vertical water tunnels, operating by gravity draining. These studies in water are based on the hydraulic analogy of aerodynamic incompressible flows. Flow visualization is archieved by liquid tracers (dye emissions) or gaseous tracers (fine air bubbles in suspension in water). In many cases, the pictures at normal speed or long exposure time are insufficient, for they do not permit to distinguish all the details of the phenomena, due to an averaging or motion effect. Furthermore they must be completed with high speed pictures. This is illustrated by a few visua-lization examples recently obtained on following themes - two dimensional flow around a fixed cylinder, first at the start of the flow (symmetrical vortex), then in steady regime (periodic vortex street) ; - laminar-turbulent transition in a boundary layer along a cylindrical body at zero angle of attack ; - flow separation around a sphere and wake in steady regime at small and high Reynolds numbers; - flow separation around a profile, first with fixed incidence, then with harmonic oscillations in pitch ; - core structure of a longitudinal vortex issued from a wing first organized, then disintegrated under the effect of a lengthwise pressure gradient (vortex breakdown) ; - mixing zone around a turbulent axisymmetric jet, characterized by the formation of large vortex struc-tures ; - hovering tests of an helicopter rotor, first at the start of the rotation, then in established regime, finally in cruise flight ; - case of a complete helicopter model in cruise-flight, with air-intake simulation, gas exhaust and tail rotor ; - flow around a complete delta-wing aircraft model at mean or high angle of attack, first in steady regime, then with harmonic oscillations in yaw or pitch. These results illustrate the contribution of

  13. Quantitative Image Analysis Techniques with High-Speed Schlieren Photography

    Science.gov (United States)

    Pollard, Victoria J.; Herron, Andrew J.

    2017-01-01

    Optical flow visualization techniques such as schlieren and shadowgraph photography are essential to understanding fluid flow when interpreting acquired wind tunnel test data. Output of the standard implementations of these visualization techniques in test facilities are often limited only to qualitative interpretation of the resulting images. Although various quantitative optical techniques have been developed, these techniques often require special equipment or are focused on obtaining very precise and accurate data about the visualized flow. These systems are not practical in small, production wind tunnel test facilities. However, high-speed photography capability has become a common upgrade to many test facilities in order to better capture images of unsteady flow phenomena such as oscillating shocks and flow separation. This paper describes novel techniques utilized by the authors to analyze captured high-speed schlieren and shadowgraph imagery from wind tunnel testing for quantification of observed unsteady flow frequency content. Such techniques have applications in parametric geometry studies and in small facilities where more specialized equipment may not be available.

  14. Analysis of high-speed digital phonoscopy pediatric images

    Science.gov (United States)

    Unnikrishnan, Harikrishnan; Donohue, Kevin D.; Patel, Rita R.

    2012-02-01

    The quantitative characterization of vocal fold (VF) motion can greatly enhance the diagnosis and treatment of speech pathologies. The recent availability of high-speed systems has created new opportunities to understand VF dynamics. This paper presents quantitative methods for analyzing VF dynamics with high-speed digital phonoscopy, with a focus on expected VF changes during childhood. A robust method for automatic VF edge tracking during phonation is introduced and evaluated against 4 expert human observers. Results from 100 test frames show a subpixel difference between the VF edges selected by algorithm and expert observers. Waveforms created from the VF edge displacement are used to created motion features with limited sensitivity to variations of camera resolution on the imaging plane. New features are introduced based on acceleration ratios of critical points over each phonation cycle, which have the potential for studying issues related to impact stress. A novel denoising and hybrid interpolation/extrapolation scheme is also introduced to reduce the impact of quantization errors and large sampling intervals relative to the phonation cycle. Features extracted from groups of 4 adults and 5 children show large differences for features related to asymmetry between the right and left fold and consistent differences for impact acceleration ratio.

  15. 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.

  16. Analysis and control of high-speed wheeled vehicles

    Science.gov (United States)

    Velenis, Efstathios

    In this work we reproduce driving techniques to mimic expert race drivers and obtain the open-loop control signals that may be used by auto-pilot agents driving autonomous ground wheeled vehicles. Race drivers operate their vehicles at the limits of the acceleration envelope. An accurate characterization of the acceleration capacity of the vehicle is required. Understanding and reproduction of such complex maneuvers also require a physics-based mathematical description of the vehicle dynamics. While most of the modeling issues of ground-vehicles/automobiles are already well established in the literature, lack of understanding of the physics associated with friction generation results in ad-hoc approaches to tire friction modeling. In this work we revisit this aspect of the overall vehicle modeling and develop a tire friction model that provides physical interpretation of the tire forces. The new model is free of those singularities at low vehicle speed and wheel angular rate that are inherent in the widely used empirical static models. In addition, the dynamic nature of the tire model proposed herein allows the study of dynamic effects such as transients and hysteresis. The trajectory-planning problem for an autonomous ground wheeled vehicle is formulated in an optimal control framework aiming to minimize the time of travel and maximize the use of the available acceleration capacity. The first approach to solve the optimal control problem is using numerical techniques. Numerical optimization allows incorporation of a vehicle model of high fidelity and generates realistic solutions. Such an optimization scheme provides an ideal platform to study the limit operation of the vehicle, which would not be possible via straightforward simulation. In this work we emphasize the importance of online applicability of the proposed methodologies. This underlines the need for optimal solutions that require little computational cost and are able to incorporate real, unpredictable

  17. Simulation Analysis Module of High-speed Rail Bearings Based on Secondary Development in ADAMS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; YE Jun; XU Juan; LUO Yi-chao

    2013-01-01

    This paper develops a strong secondary development based on ADAMS feature which creates high-speed rail bearings for simulation analysis module. This thesis is in the case of non-circular pattern instructions of how to achieve rapid roller modeling, with analysis of functions and parameters required for the design of the simulation module of the high-speed rail bearing , as well as the design of dialog boxes, the environment and file structure. The specific modules is based on the secondary development language provided by ADAMS/View. Through the menus, dialog boxes which input parameters, it can achieve high iron bearing automatic modeling, dynamic analysis and post-processing to simplify the analysis of high-speed rail bearing operations, as well as improving the high-speed rail bearing development efficiency.

  18. One high-efficiency analysis method for high-speed circuit networks containing distributed parameter elements

    Institute of Scientific and Technical Information of China (English)

    Lei DOU; Zhiquan WANG

    2005-01-01

    In the field of high-speed circuits,the analysis of mixed circuit networks containing both distributed parameter elements and lumped parameter elements becomes ever important.This paper presents a new method for analyzing mixed circuit networks.It adds transmission line end currents to the circuit variables of the classical modified nodal approach and can be applied directly to the mixed circuit networks.We also introduce a frequency-domain technique without requiring decoupling for multiconductor transmission lines.The two methods are combined together to efficiently analyze high-speed circuit networks containing uniform,nonuniform,and frequency-dependent transmission lines.Numerical experiment is presented and the results are compared with that computed by PSPICE.

  19. Signal Integrity Analysis of High-Speed Interconnects

    CERN Document Server

    Oltean Karlsson, A

    2007-01-01

    LHC detectors and future experiments will produce very large amount of data that will be transferred at multi-Gigabit speeds. At such data rates, signal-integrity effects become important and traditional rules of thumb are no longer enough for the design and layout of the traces. Simulations for signal-integrity effects at board level provide a way to study and validate several scenarios before arriving at a set of optimized design rules prior to building the actual printed circuit board (PCB). This article describes some of the available tools at CERN. Two case studies will be used to highlight the capabilities of these programs.

  20. High-Speed Video Analysis in a Conceptual Physics Class

    Science.gov (United States)

    Desbien, Dwain M.

    2011-01-01

    The use of probe ware and computers has become quite common in introductory physics classrooms. Video analysis is also becoming more popular and is available to a wide range of students through commercially available and/or free software. Video analysis allows for the study of motions that cannot be easily measured in the traditional lab setting…

  1. Capacity analysis for high-speed terahertz wireless communications

    DEFF Research Database (Denmark)

    Dogadaev, Anton Konstantinovich; Lavrinenko, Andrei; Tafur Monroy, Idelfonso

    2012-01-01

    We report on the analytical capacity analysis of terahertz wireless communications supporting 275–325 GHz frequency band. Our goal in this paper is to provide design guidelines for close proximity links with transmission capacity beyond 100 Gbit/s.......We report on the analytical capacity analysis of terahertz wireless communications supporting 275–325 GHz frequency band. Our goal in this paper is to provide design guidelines for close proximity links with transmission capacity beyond 100 Gbit/s....

  2. Trends in 100m Wind Speed using Global High-Resolution Downscaled Analysis

    Science.gov (United States)

    McGraw, Z.

    2015-12-01

    The strength and variability of the wind energy resource are expected to be susceptible to the complex changes undergoing Earth's climate system. A variety of physical mechanisms for long-term wind speed changes has been proposed, including modified temperature gradients, shifting storm tracks and altered land use. This study is an analysis of multi-decadal wind speed trends within a high-resolution downscaled global analysis provided by our collaborators at Vestas Wind Systems A/S. We have sought to identify the regions and landscape types that most exhibit long-term changes to wind speed and identify the mechanisms responsible.

  3. 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.

  4. Study and Performance Analysis of High Frequency and High Speed Operational Amplifier

    Directory of Open Access Journals (Sweden)

    Puneet Goyal

    2013-03-01

    Full Text Available The performance analysis of the two stage CMOS operational amplifiers employing Miller capacitor in conjunction with the common gate current buffer is presented. Unlike the previously reported design strategies of the opamp of this type, this results in the opamp with a lower power supply requirements, better phase margin and better speed. The Opamp is designed to exhibit a unity gain frequency of 1.46GHz and exhibits a gain of 115dB with a 117˚ phase margin. The slew rate is found as high as 50 V/µs. Power supply noise rejection is also better in case of current buffer compensation. As compared to the conventional approach, the current buffer compensation method results in a higher unity gain frequency hence higher bandwidth under the same load condition. Simulation has been carried out in LT-SPICE

  5. The application of high-speed cinematography for the quantitative analysis of equine locomotion.

    Science.gov (United States)

    Fredricson, I; Drevemo, S; Dalin, G; Hjertën, G; Björne, K

    1980-04-01

    Locomotive disorders constitute a serious problem in horse racing which will only be rectified by a better understanding of the causative factors associated with disturbances of gait. This study describes a system for the quantitative analysis of the locomotion of horses at speed. The method is based on high-speed cinematography with a semi-automatic system of analysis of the films. The recordings are made with a 16 mm high-speed camera run at 500 frames per second (fps) and the films are analysed by special film-reading equipment and a mini-computer. The time and linear gait variables are presented in tabular form and the angles and trajectories of the joints and body segments are presented graphically.

  6. Using High Speed Smartphone Cameras and Video Analysis Techniques to Teach Mechanical Wave Physics

    Science.gov (United States)

    Bonato, Jacopo; Gratton, Luigi M.; Onorato, Pasquale; Oss, Stefano

    2017-01-01

    We propose the use of smartphone-based slow-motion video analysis techniques as a valuable tool for investigating physics concepts ruling mechanical wave propagation. The simple experimental activities presented here, suitable for both high school and undergraduate students, allows one to measure, in a simple yet rigorous way, the speed of pulses…

  7. A study on high speed coupling design for wind turbine using a finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyoung Woo; Kang, Jong Hun [Dept. of Mechatronics Engineering, Jungwon University, Geosan (Korea, Republic of); Han, Jeong Young [Pusan Educational Center for Computer Aided Machine Design, Pusan University, Busan (Korea, Republic of)

    2016-08-15

    The purpose of this study is to design a high speed coupling for 3 MW wind turbines and evaluate its structural stability. A basic analysis was performed to assess the structural stability of two materials, SPS6 steel plate and a composite material (Glass7628, Glass/Epoxy), in relation to misalignment in the axial and radial directions. The entire model was analyzed for a high speed coupling based on the SPS6 steel plate, which was found to have higher stability among the two materials, and safety factors were estimated for various levels of power delivery. To test the proposed high speed coupling design, a performance test was carried out to verify the stability of the final product.

  8. 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.

  9. High-speed nonlinear finite element analysis for surgical simulation using graphics processing units.

    Science.gov (United States)

    Taylor, Z A; Cheng, M; Ourselin, S

    2008-05-01

    The use of biomechanical modelling, especially in conjunction with finite element analysis, has become common in many areas of medical image analysis and surgical simulation. Clinical employment of such techniques is hindered by conflicting requirements for high fidelity in the modelling approach, and fast solution speeds. We report the development of techniques for high-speed nonlinear finite element analysis for surgical simulation. We use a fully nonlinear total Lagrangian explicit finite element formulation which offers significant computational advantages for soft tissue simulation. However, the key contribution of the work is the presentation of a fast graphics processing unit (GPU) solution scheme for the finite element equations. To the best of our knowledge, this represents the first GPU implementation of a nonlinear finite element solver. We show that the present explicit finite element scheme is well suited to solution via highly parallel graphics hardware, and that even a midrange GPU allows significant solution speed gains (up to 16.8 x) compared with equivalent CPU implementations. For the models tested the scheme allows real-time solution of models with up to 16,000 tetrahedral elements. The use of GPUs for such purposes offers a cost-effective high-performance alternative to expensive multi-CPU machines, and may have important applications in medical image analysis and surgical simulation.

  10. 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.

  11. Analysis and control of flow at suction connection in high-speed centrifugal pump

    Directory of Open Access Journals (Sweden)

    Wen-wu Song

    2016-12-01

    Full Text Available The backflow vortexes at the suction connection in high-speed centrifugal pumps have negative effect on the flow field. Setting an orifice plate in front of the inducer is able to decrease the negative effect caused by backflow vortexes. The traditional plate is able to partially control the backflow vortexes, but a small part of the vortex is still in the inlet and the inducer. Four new types of orifice plates were created, and the control effects on backflow vortexes were analyzed. The ANSYS-CFX software was used to numerically simulate a high-speed centrifugal pump. The variations of streamline and velocity vectors at the suction connection were analyzed. Meanwhile, the effects of these plates on the impeller pressure and the internal flow field of the inducer were analyzed. Numerically, simulation and experimental data analysis methods were used to compare the head and efficiency of the high-speed pumps. The results show that the C-type orifice plate can improve the backflow vortex, reduce the low-pressure area, and improve the hydraulic performance of the high-speed pump.

  12. Multimedia Traffic Queueing Analysis in High-Speed Networks: a Frequency Domain Approach

    Science.gov (United States)

    Hwang, Chia-Lin

    Multimedia traffic in high speed networks possesses correlation and burstiness properties. Classical queueing theory has generally ignored such properties by making renewal assumption on message interarrival time. Developing a new traffic theory for integration of multimedia services on high speed networks becomes absolutely essential. In this dissertation, we explore a new concept of spectral characterization of wide-band input process in high speed networks. It provides us a much richer and heterogeneous input environment, while keeping the complexity of queueing analysis tractable. The correlation nature of multimedia traffic is well captured by the input spectral functions. The queue response to the power spectrum and higher order statistics has been studied. Our study shows that the input power spectrum is the most essential statistic for queueing analysis. Further, the input power in low-frequency band has dominant impact on queueing performance, whereas the high-frequency power to a large extent can be neglected. Understanding of queue response to input spectrum provides us a great deal of knowledge to develop advanced network traffic measure theory, and to introduce effective network resource allocation policies. The interrelationship between the traffic spectral statistics and link capacity allocation in high speed network has been investigated. Finally we developed a sophisticated computational tool, called SMAQ, that can integrate traffic measurement and queueing analysis for stochastic modeling. The SMAQ tool takes a unique frequency-domain approach to combine the techniques of signal processing and performance analysis. Essentially, signal processing techniques are used to obtain the steady -state and second-order statistics of a traffic stream. The focus here is on the construction of a special class of Markov chains that can statistically match with each given traffic stream (or superposition of different traffic streams). The analytical queueing

  13. Systems analysis and design for next generation high-speed video systems

    Science.gov (United States)

    Snyder, Donald R.; Rowe, W. J.

    1991-01-01

    There is a well documented desire in the scientific research, development and test community to supplement and replace high speed film cameras with electronic imaging systems where immediate results are needed. Examples of the development of commercially practical systems were demonstrated by the Spin Physics SP-2000, and Ektapro 1000 as well as medium speed systems from NAG of Japan. LHESA of France has recently anounced the development of a new high speed system capable of 2000 frames per second-. Battelle Memorial Institute in Columbus, Ohio has developed a prototype of a high speedA low resolution, self triggering system (64 by 64 at 11,000 frames per second)L. All of the systems are constrained by two common problems: limited resolution and light sensitivity, as compared with traditional film and conventional video type instrumentation systems. Incremental advances have been made to improve the light sensitivity and operational utility of the current generation systems. Among these improvements have been the image intensified Ektapro and Solid tate storage module both from Spin Physics (Motion Analysis Division of Kodak.

  14. Development of High Speed Interferometry Imaging and Analysis Techniques for Compressible Dynamic Stall

    Science.gov (United States)

    Chandrasekhara, M. S.; Carr, L. W.; Wilder, M. C.

    1998-01-01

    The development of a high-speed, phase-locked, realtime, point diffraction interferometry system for quantitative imaging unsteady separated flows is described. The system enables recording of up to 224 interferograms of the dynamic stall flow over an oscillating airfoil using a drum camera at rates of up to 40 KHz controlled by custom designed electronic interlocking circuitry. Several thousand interferograms of the flow have been obtained using this system. A comprehensive image analysis package has been developed for automatic processing of this large number of images. The software has been specifically tuned to address the special characteristics of airfoil flow interferograms. Examples of images obtained using the standard and the high-speed interferometry techniques are presented along with a demonstration of the image processing routine's ability to resolve the fine details present in these images.

  15. A high speed data acquisition system for the analysis of velocity, density, and total temperature fluctuations at transonic speeds

    Science.gov (United States)

    Clukey, Steven J.; Jones, Gregory S.; Stainback, P. Calvin

    1988-01-01

    The use of a high-speed Dynamic Data Acquisition System (DDAS) to measure simultaneously velocity, density, and total temperature fluctuations is described. The DDAS is used to automate the acquisition of hot-wire calibration data. The data acquisition, data handling, and data reporting techiques used by DDAS are described. Sample data are used to compare results obtained with the DDAS with those obtained from the FM tape and post-test digitization method.

  16. Performance analysis of a new positron camera geometry for high speed, fine particle tracking

    Science.gov (United States)

    Sovechles, J. M.; Boucher, D.; Pax, R.; Leadbeater, T.; Sasmito, A. P.; Waters, K. E.

    2017-09-01

    A new positron camera arrangement was assembled using 16 ECAT951 modular detector blocks. A closely packed, cross pattern arrangement was selected to produce a highly sensitive cylindrical region for tracking particles with low activities and high speeds. To determine the capabilities of this system a comprehensive analysis of the tracking performance was conducted to determine the 3D location error and location frequency as a function of tracer activity and speed. The 3D error was found to range from 0.54 mm for a stationary particle, consistent for all tracer activities, up to 4.33 mm for a tracer with an activity of 3 MBq and a speed of 4 m · s-1. For lower activity tracers (sensitive to increases in speed, increasing to 28 mm (at 4 m · s-1), indicating that at these conditions a reliable trajectory is not possible. These results expanded on, but correlated well with, previous literature that only contained location errors for tracer speeds up to 1.5 m · s-1. The camera was also used to track directly activated mineral particles inside a two-inch hydrocyclone and a 142 mm diameter flotation cell. A detailed trajectory, inside the hydrocyclone, of a  -212  +  106 µm (10-1 MBq) quartz particle displayed the expected spiralling motion towards the apex. This was the first time a mineral particle of this size had been successfully traced within a hydrocyclone, however more work is required to develop detailed velocity fields.

  17. Gas film disturbance characteristics analysis of high-speed and high-pressure dry gas seal

    Science.gov (United States)

    Chen, Yuan; Jiang, Jinbo; Peng, Xudong

    2016-08-01

    The dry gas seal(DGS) has been widely used in high parameters centrifugal compressor, but the intense vibrations of shafting, especially in high-speed condition, usually result in DGS's failure. So the DGS's ability of resisting outside interference has become a determining factor of the further development of centrifugal compressor. However, the systematic researches of which about gas film disturbance characteristics of high parameters DGS are very little. In order to study gas film disturbance characteristics of high-speed and high-pressure spiral groove dry gas seal(S-DGS) with a flexibly mounted stator, rotor axial runout and misalignment are taken into consideration, and the finite difference method and analytical method are used to analyze the influence of gas film thickness disturbance on sealing performance parameters, what's more, the effects of many key factors on gas film thickness disturbance are systematically investigated. The results show that, when sealed pressure is 10.1MPa and seal face average linear velocity is 107.3 m/s, gas film thickness disturbance has a significant effect on leakage rate, but has relatively litter effect on open force; Excessively large excitation amplitude or excessively high excitation frequency can lead to severe gas film thickness disturbance; And it is beneficial to assure a smaller gas film thickness disturbance when the stator material density is between 3.1 g/cm3 to 8.4 g/cm3; Ensuring sealing performance while minimizing support axial stiffness and support axial damping can help to improve dynamic tracking property of dry gas seal. The proposed research provides the instruction to optimize dynamic tracking property of the DGS.

  18. Analysis of a one mirror inclined three-mirror cavity photodetector for high-speed application

    Institute of Scientific and Technical Information of China (English)

    Yongqing Huang; Cheng Huang; Qi Wang; Hui Huang; Xingyan Wang; Xiaomin Ren

    2005-01-01

    @@ There is a tradeoff between the quantum efficiency and the spectral response linewidth in resonant-cavityenhanced (RCE) photodetectors. Recently a new type of photodetector structure has been proposed, which utilizes an inclined mirror in a three-mirror cavity. It decouples the quantum efficiency and the spectral response linewidth and has high response speed, high quantum efficiency, and narrow linewidth simultaneously. The analysis result indicates that the linewidth of 0.8 nm and quantum efficiency higher than 70%can be achieved on this device. For a 30×30 μm2 device, the maximum bandwidth approaches 23 GHz.

  19. A Reliability Accelerated Test of High-speed Punch Based on Failure Analysis

    Directory of Open Access Journals (Sweden)

    Chen Lan

    2016-01-01

    Full Text Available By analyzing the maintainability data of a certain high-speed punch, its main fault modes, such as oil/gas parts damage, parts damage and leakages, were identified. According to the fault signal measurability and the accelerated failure mechanism, the content and scheme of a reliability accelerated test (RAT were planned specifically, which was partly verified by some tests on a high-speed punch. This paper provides a basis for the RAT of high-speed punch.

  20. Analysis of Accuracy of a High-speed Mobile Platform Control System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The efficient manufacture technique involves a high-speed control of platform mobile system. A linear acutor is presented in this paper. The linear acutor is constructed as a linear stepper motor. However, to sustain both high accuracy and high speed for the position and speed control, A single-stack computer system is constructed and a special control algorithm is prescribed to controled the linear actuator continuously. In this paper, the nonlinear errors resulted from the magnetic saturation and the h...

  1. Analysis of stress and natural frequencies of high-speed spatial parallel mechanism

    Institute of Scientific and Technical Information of China (English)

    陈修龙; 李文彬; 邓昱; 李云峰

    2013-01-01

    In order to grasp the dynamic behaviors of 4-UPS-UPU high-speed spatial parallel mechanism, the stress of driving limbs and natural frequencies of parallel mechanism were investigated. Based on flexible multi-body dynamics theory, the dynamics model of 4-UPS-UPU high-speed spatial parallel mechanism without considering geometric nonlinearity was derived. The stress of driving limbs and natural frequencies of 4-UPS-UPU parallel mechanism with specific parameters were analyzed. The relationship between the basic parameters of parallel mechanism and its dynamic behaviors, such as stress of driving limbs and natural frequencies of parallel mechanism, were discussed. The numerical simulation results show that the stress and natural frequencies are relatively sensitive to the section parameters of driving limbs, the characteristic parameters of material on driving limbs, and the mass of moving platform. The researches can provide important theoretical base of the analysis of dynamic behaviors and optimal design for high-speed spatial parallel mechanism.

  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. 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.

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

    Directory of Open Access Journals (Sweden)

    Do-Kwan Hong

    2014-08-01

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

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

    Science.gov (United States)

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

    2014-08-29

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

  6. 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.

  7. Applications of copper vapor laser lighting in high-speed motion analysis

    Science.gov (United States)

    Hogan, Daniel C.

    1991-01-01

    Over the past few years copper vapor lasers have become an important tool in high speed photography as a high-tech strobe lighting source. The short flash duration ( 025 microseconds) high brightness (of the order of 20 million Lumens) and high flash rates (32 per second from a single laser 96 per second from three lasers) of copper vapor lasers have enabled high resolution analysis of processes that previously could not be explored using conventional incandescent continuous or strobe lighting sources. A summary of applications that have benefited from the use of copper laser lighting will be presented. These applications include: analysis of shock waves in turbine engine blades analysis of spinning fibers in the textile industry analysis of the bursting of high pressure storage vessels analysis of turbulent flow in internal combustion engines and capture of ballistic data of objects travelling in excess of 1500ms1(3 mph). Discussion of why copper laser lighting was crucial in each of these applications will be presented.

  8. Using high speed smartphone cameras and video analysis techniques to teach mechanical wave physics

    Science.gov (United States)

    Bonato, Jacopo; Gratton, Luigi M.; Onorato, Pasquale; Oss, Stefano

    2017-07-01

    We propose the use of smartphone-based slow-motion video analysis techniques as a valuable tool for investigating physics concepts ruling mechanical wave propagation. The simple experimental activities presented here, suitable for both high school and undergraduate students, allows one to measure, in a simple yet rigorous way, the speed of pulses along a spring and the period of transverse standing waves generated in the same spring. These experiments can be helpful in addressing several relevant concepts about the physics of mechanical waves and in overcoming some of the typical student misconceptions in this same field.

  9. CFD Analysis of a Penta-hulled, Air-Entrapment, High-Speed Planning Vessel

    Science.gov (United States)

    2008-03-01

    f. Hydrofoils ................................................................................10 4. Analytic Hierarchy Process...ruled out as a possibility. f. Hydrofoils The main advantage to a hydrofoil hull shape is the high speeds created during non displacement mode. The...internal arrangement space. However, the vulnerability of the foils during high speed caused us to rule out the hydrofoil during the initial study. 4

  10. A high speed data acquisition and processing system for real time data analysis and control

    Science.gov (United States)

    Ferron, J. R.

    1992-11-01

    A high speed data acquisition system which is closely coupled with a high speed digital processor is described. Data acquisition at a rate of 40 million 14 bit data values per second is possible simultaneously with data processing at a rate of 80 million floating point operations per second. This is achieved by coupling a commercially available VME format single board computer based on the Intel i860 microprocessor with a custom designed first-in, first-out memory circuit that transfers data at high speed to the processor board memory. Parallel processing to achieve increased computation speed is easily implemented because the data can be transferred simultaneously to multiple processor boards. Possible applications include high speed process control and real time data reduction. A specific example is described in which this hardware is used to implement a feedback control system for 18 parameters which uses 100 input signals and achieves a 100 μs cycle time.

  11. 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.

  12. Simulation and Experimental Analysis of Super High-Speed Grinding of Ductile Material

    Institute of Scientific and Technical Information of China (English)

    SHIMIZU; Jun; EDA; Hiroshi

    2002-01-01

    This study aims to reduce the work-affected layer of the machined surface by carrying out the grinding at the speed over static pr o pagation speed of plastic wave of ductile materials and also aims to clarify suc h super high-speed machining mechanism.This paper reports on the result obtain ed through the molecular dynamics simulations and experiments on the super-spee d grinding below and beyond static propagation speed of aluminum.From the simul ation results,it is verified that the plastic deformation ...

  13. ANALYSIS ON MOTION STABILITY OF A HIGH-SPEED ROTOR-BEARING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Zhang Junhong; Sun Shaojun

    2005-01-01

    A non-linear dynamic model of one type of high-speed rotor system with gas supporting system is set up. The laws between the capacity force and the parameters of bearing, the static equilibrium position and rotating speed are studied on the basis of above model. Then, the failure rotating speed is given in the working state, and the relation between the minimum failure rotating speed and clearance of bearing is also studied. At last, the stability and failure condition are discussed in different working conditions.

  14. High-Speed Research: 1994 Sonic Boom Workshop. Configuration, Design, Analysis and Testing

    Science.gov (United States)

    McCurdy, David A. (Editor)

    1999-01-01

    The third High-Speed Research Sonic Boom Workshop was held at NASA Langley Research Center on June 1-3, 1994. The purpose of this workshop was to provide a forum for Government, industry, and university participants to present and discuss progress in their research. The workshop was organized into sessions dealing with atmospheric propagation; acceptability studies; and configuration design, and testing. Attendance at the workshop was by invitation only. The workshop proceedings include papers on design, analysis, and testing of low-boom high-speed civil transport configurations and experimental techniques for measuring sonic booms. Significant progress is noted in these areas in the time since the previous workshop a year earlier. The papers include preliminary results of sonic boom wind tunnel tests conducted during 1993 and 1994 on several low-boom designs. Results of a mission performance analysis of all low-boom designs are also included. Two experimental methods for measuring near-field signatures of airplanes in flight are reported.

  15. Development, Analysis and Testing of the High Speed Research Flexible Semispan Model

    Science.gov (United States)

    Schuster, David M.; Spain, Charles V.; Turnock, David L.; Rausch, Russ D.; Hamouda, M-Nabil; Vogler, William A.; Stockwell, Alan E.

    1999-01-01

    This report presents the work performed by Lockheed Martin Engineering and Sciences (LMES) in support of the High Speed Research (HSR) Flexible Semispan Model (FSM) wind-tunnel test. The test was conducted in order to assess the aerodynamic and aeroelastic character of a flexible high speed civil transport wing. Data was acquired for the purpose of code validation and trend evaluation for this type of wing. The report describes a number of activities in preparing for and conducting the wind-tunnel test. These included coordination of the design and fabrication, development of analytical models, analysis/hardware correlation, performance of laboratory tests, monitoring of model safety issues, and wind-tunnel data acquisition and reduction. Descriptions and relevant evaluations associated with the pretest data are given in sections 1 through 6, followed by pre- and post-test flutter analysis in section 7, and the results of the aerodynamics/loads test in section 8. Finally, section 9 provides some recommendations based on lessons learned throughout the FSM program.

  16. The Performance Analysis of Ultra High Speed PM Type Synchronous Motor-Generator for Micro Turbine

    Science.gov (United States)

    Hong, Do-Kwan; Woo, Byung-Chul; Jeong, Yeon-Ho; Koo, Dae-Hyun; Cho, Yun-Hyun

    This paper deals with loss analysis, structural, thermal-fluid and rotordynamics (critical speed and unbalance) which need in developing the motor-generator. This machine has designed of a generator of 800 W, 400 krpm and a starter of 400 W, 200 krpm. The generated losses of motor-generator are derived by magnetic analysis. Thermal-fluid analysis is performed using loss analysis result. The critical speed is extracted by Campbell diagram. Unbalance vibration response analysis enable to predict the expected vibration amplitude by unbalance. The motor-generator is well-developed using the applied several techniques of analysis.

  17. Flow field analysis of high-speed helium turboexpander for cryogenic refrigeration and liquefaction cycles

    Science.gov (United States)

    Sam, Ashish Alex; Ghosh, Parthasarathi

    2017-03-01

    Turboexpander constitutes one of the vital components of Claude cycle based helium refrigerators and liquefiers that are gaining increasing technological importance. These turboexpanders which are of radial inflow in configuration are generally high-speed micro turbines, due to the low molecular weight and density of helium. Any improvement in efficiency of these machines requires a detailed understanding of the flow field. Computational Fluid Dynamics analysis (CFD) has emerged as a necessary tool for the determination of the flow fields in cryogenic turboexpanders, which is often not possible through experiments. In the present work three-dimensional transient flow analysis of a cryogenic turboexpander for helium refrigeration and liquefaction cycles were performed using Ansys CFX®, to understand the flow field of a high-speed helium turboexpander, which in turn will help in taking appropriate decisions regarding modifications of established design methodology for improved efficiency of these machines. The turboexpander is designed based on Balje's nsds diagram and the inverse design blade profile generation formalism prescribed by Hasselgruber and Balje. The analyses include the study of several losses, their origins, the increase in entropy due to these losses, quantification of losses and the effects of various geometrical parameters on these losses. Through the flow field analysis it was observed that in the nozzle, flow separation at the nozzle blade suction side and trailing edge vortices resulted in loss generation, which calls for better nozzle blade profile. The turbine wheel flow field analysis revealed that the significant geometrical parameters of the turbine wheel blade like blade inlet angle, blade profile, tip clearance height and trailing edge thickness need to be optimised for improved performance of the turboexpander. The detailed flow field analysis in this paper can be used to improve the mean line design methodology for turboexpanders used

  18. High speed, high resolution, and continuous chemical analysis of ice cores using a melter and ion chromatography.

    Science.gov (United States)

    Cole-Dai, Jihong; Budner, Drew M; Ferris, Dave G

    2006-11-01

    Measurement of trace chemical impurities in ice cores contributes to the reconstruction of records of the atmospheric environment and of the climate system. Ion chromatography (IC) is an effective analytical technique for ionic species in ice cores but has been used on discretely prepared ice samples, resulting in extensive and slow sample preparation and potential for contamination. A new technique has been developed that utilizes IC as the online detection technique in a melter-based continuous flow system for quantitative determination of major ionic chemical impurities. The system, called CFA-IC for continuous flow analysis with ion chromatography detection, consists of an ice core melter, several ion chromatographs, and an interface that distributes meltwater to the IC instruments. The CFA-IC technique combines the accuracy, precision, and ease of use of IC measurement with the enhanced speed and depth resolution of continuous melting systems and is capable of virtually continuous, high-speed and high-resolution chemical analysis of long ice cores. The new technique and operating procedures have been tested and validated with the analysis of over 100 m of ice cores from Antarctica. The current CFA-IC system provides an all-major-ion analysis speed of up to 8 m a day at a depth resolution of approximately 2 cm.

  19. Dynamic Analysis of Flexible Cage of High-speed Angular Contact Ball Bearing

    Institute of Scientific and Technical Information of China (English)

    邓四二; 谢鹏飞; 杨海生; 高银涛

    2012-01-01

    A dynamics formula was established for the flexible cage of high-speed angular contact ball bearing. A modified Craig-Bampton component mode synthetic method was used to establish the formula with regard to the flexibility of cage and based on a dynamic analysis of angular contact ball bearing, and a rigid-flexible multi-body dynamic analysis program was developed using ADAMS, which is verified by a computation example of Gupta. The results show that it' s not likely to keep the rotation smoothness of cage when the ratio of pocket clearance to guiding clearance and the ratio of radial load to axial load become too large or too small. By comparison, the flexible cage runs more smoothly than the rigid cage.

  20. Sensitivity analysis of distributed parameter elements In high-speed circuit networks

    Institute of Scientific and Technical Information of China (English)

    Lei DOU; Zhiquan WANG

    2007-01-01

    This paper presents an analysis method,based on MacCormack's technique,for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks.Sensitivities can be calculated from electrical and physical parameters of the distributed parameter elements.The proposed method is a direct numerical method of time-space discretization and does not require complicated mathematical deductive process.Therefore,it is very convenient to program this method.It can be applied to sensitivity analysis of general transmission lines in linear or nonlinear circuit networks.The proposed method is second-order-accurate.Numerical experiment is presented to demonstrate its accuracy and efficiency.

  1. 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.

  2. Safety analysis and realization of safe information transmission optical LAN on high-speed railway

    Science.gov (United States)

    Tao, Ying; Wu, Chongqing; Li, Zuoyi

    2001-10-01

    High-speed railway that has been progressing very quickly is one of the greatest techniques in present time because of its high speed, economy, comfort, environment benefits and other advantages. And among all of these, safe is the backbone and lifeline, so the chief task in developing high-speed railway is to establish safety guarantee system. Also in this safety guarantee system, train control is one of the key techniques to guarantee safe train operation and to advance ability of transportation, so operation safe is located in the hardcore position. That is to say, it is imperative to set up a safe, real-time and reliable automatic train control system. And we can easily find out that this kind of system is now developed and applied in many countries. Important information related to train control, such as the received and transmitted information of track-sided equipment, is called safe information, because it deals with train operation's safe, reliability, and even directly with people's life and wealth. It is so important that if there were some kind of fault with its making, transmission, or processing, fatal accident would occur. So to some degree, it is impossible to transmit and process this information through present railway communication network because of the former's extreme importance and the latter's no safe capability. Therefore, a specific communication network that mainly considers about safe transmission and management should be established in order to realize the specific function for this specific information. High-speed railway safe information transmission optical LAN, which adopts optical fiber as transmission media and transmits safe information, is a kind of LAN designed for the request for safe, real-time and highly reliable automatic train control system in the process of our country's high-speed railway construction and commonly train speed. In this paper, after analyzing the characteristics of automatic train control system and the

  3. Performance Analysis of Modified Drain Gating Techniques for Low Power and High Speed Arithmetic Circuits

    Directory of Open Access Journals (Sweden)

    Shikha Panwar

    2014-01-01

    Full Text Available This paper presents several high performance and low power techniques for CMOS circuits. In these design methodologies, drain gating technique and its variations are modified by adding an additional NMOS sleep transistor at the output node which helps in faster discharge and thereby providing higher speed. In order to achieve high performance, the proposed design techniques trade power for performance in the delay critical sections of the circuit. Intensive simulations are performed using Cadence Virtuoso in a 45 nm standard CMOS technology at room temperature with supply voltage of 1.2 V. Comparative analysis of the present circuits with standard CMOS circuits shows smaller propagation delay and lesser power consumption.

  4. Bullet Retarding Forces in Ballistic Gelatin by Analysis of High Speed Video

    CERN Document Server

    Gaylord, Steven; Courtney, Michael; Courtney, Amy

    2013-01-01

    Though three distinct wounding mechanisms (permanent cavity, temporary cavity, and ballistic pressure wave) are described in the wound ballistics literature, they all have their physical origin in the retarding force between bullet and tissue as the bullet penetrates. If the bullet path is the same, larger retarding forces produce larger wounding effects and a greater probability of rapid incapacitation. By Newton's third law, the force of the bullet on the tissue is equal in magnitude and opposite in direction to the force of the tissue on the bullet. For bullets penetrating with constant mass, the retarding force on the bullet can be determined by frame by frame analysis of high speed video of the bullet penetrating a suitable tissue simulant such as calibrated 10% ballistic gelatin. Here the technique is demonstrated with 9mm NATO bullets, 32 cm long blocks of gelatin, and a high speed video camera operating at 20,000 frames per second. It is found that different 9mm NATO bullets have a wide variety of pot...

  5. Analysis of technological and competitive trends of weight reduction in high speed rolling stock industry

    OpenAIRE

    Prieto Moneo, Álvaro

    2016-01-01

    The incorporation to the transport of passengers sector of the high speed industry is preceded by a global society, which requires the possibility to travel quickly, comfortably and efficiently, imposing the current attitude of the concern with the environment. The development of the rail sector over recent decades, and especially in recent years, along with the technological development has allowed the formation of a network of high speed lines around the greatest part of the planet. Due...

  6. 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.

  7. Cost-Benefit Analysis of High-Speed Rail Link between Hong Kong and Mainland China

    Directory of Open Access Journals (Sweden)

    R. Tao

    2011-07-01

    Full Text Available The Legislative Council in Hong Kong has approved a funding of USD$8.60 billion to build the high-speed rail (HSR line linking mainland China. HSR is a break-through technology that allows trains running at a speed over 250 km per hour. The most controversial part of the HSR investment is whether its cost could be compensated by the social benefits. In this study, a cost-benefit analysis of the Hong Kong to mainland HSR (HKM-HSR line is carried out. First, all the direct and indirect costs, and social benefits are defined; then, monetary equivalents are assigned to these elements; third, all the future values are discounted into present values and aggregated. The results show that the project has a positive net present value (NPV up to USD$2,068.49 million, which proves that the investment is worth. In addition, other transport alternatives, i.e. the existing roadway and conventional railway, are examined and compared with HKM-HSR, which unveils that HSR has the largest positive NPV among these three passenger transportation modes because of its excellent performance in ticket revenue, travel time savings and safety improvement.

  8. High-speed video imaging and digital analysis of microscopic features in contracting striated muscle cells

    Science.gov (United States)

    Roos, Kenneth P.; Taylor, Stuart R.

    1993-02-01

    The rapid motion of microscopic features such as the cross striations of single contracting muscle cells are difficult to capture with conventional optical microscopes, video systems, and image processing approaches. An integrated digital video imaging microscope system specifically designed to capture images from single contracting muscle cells at speeds of up to 240 Hz and to analyze images to extract features critical for the understanding of muscle contraction is described. This system consists of a brightfield microscope with immersion optics coupled to a high-speed charge-coupled device (CCD) video camera, super-VHS (S- VHS) and optical media disk video recording (OMDR) systems, and a semiautomated digital image analysis system. Components are modified to optimize spatial and temporal resolution to permit the evaluation of submicrometer features in real physiological time. This approach permits the critical evaluation of the magnitude, time course, and uniformity of contractile function throughout the volume of a single living cell with higher temporal and spatial resolutions than previously possible.

  9. 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.

  10. High-Speed Linear Raman Spectroscopy for Instability Analysis of a Bluff Body Flame

    Science.gov (United States)

    Kojima, Jun; Fischer, David

    2013-01-01

    We report a high-speed laser diagnostics technique based on point-wise linear Raman spectroscopy for measuring the frequency content of a CH4-air premixed flame stabilized behind a circular bluff body. The technique, which primarily employs a Nd:YLF pulsed laser and a fast image-intensified CCD camera, successfully measures the time evolution of scalar parameters (N2, O2, CH4, and H2O) in the vortex-induced flame instability at a data rate of 1 kHz. Oscillation of the V-shaped flame front is quantified through frequency analysis of the combustion species data and their correlations. This technique promises to be a useful diagnostics tool for combustion instability studies.

  11. Human engineering analysis for the high speed civil transport flight deck

    Science.gov (United States)

    Regal, David M.; Alter, Keith W.

    1993-01-01

    The Boeing Company is investigating the feasibility of building a second generation supersonic transport. If current studies support its viability, this airplane, known as the High Speed Civil Transport (HSCT), could be launched early in the next century. The HSCT will cruise at Mach 2.4, be over 300 feet long, have an initial range of between 5000 and 6000 NM, and carry approximately 300 passengers. We are presently involved in developing an advanced flight deck for the HSCT. As part of this effort we are undertaking a human engineering analysis that involves a top-down, mission driven approach that will allow a systematic determination of flight deck functional and information requirements. The present paper describes this work.

  12. Experimental Motion Analysis of Radially Rotating Beams Using High-Speed Camera and Motion Analyzer

    Directory of Open Access Journals (Sweden)

    K.H. Low

    1996-01-01

    Full Text Available Although strain gauges can be attached to a system for vibration analysis, wires connected to the strain gauges may disturb the system and affect the accuracy of the strain measurement. As an alternative, this work presents the use of a high-speed camera combined with a motion analyzer to study the motion of rotating flexible beams. One end of the beam is rigidly connected to a motor, while the other end is free. White stickers placed on selected points on a given beam are the reference points in a digitization process. The modes of the vibrating beams can be filmed and analyzed. The vibration parameters, such as deflection and frequency, can be obtained by using a film motion analyzer. The results show that the beam does not behave in a clamped-free or a pinned-free fashion, but instead occurs at an intermediate boundary between these two classical conditions.

  13. Flipping the analytical coin : closing the information flow loop in high speed (real time) analysis

    NARCIS (Netherlands)

    K.E. Shahroudi

    1997-01-01

    textabstractAnalysis modules tend to be set up as one way flow of information, i.e a clear distinction between cause and effect or input and output. However, as the speed of analysis approaches real time (or faster than movie rate), it becomes increasingly difficult for an external user to

  14. Flipping the analytical coin : closing the information flow loop in high speed (real time) analysis

    NARCIS (Netherlands)

    Shahroudi, K.E.

    1997-01-01

    Analysis modules tend to be set up as one way flow of information, i.e a clear distinction between cause and effect or input and output. However, as the speed of analysis approaches real time (or faster than movie rate), it becomes increasingly difficult for an external user to distinguish between c

  15. 1995 NASA High-Speed Research Program Sonic Boom Workshop. Volume 2; Configuration Design, Analysis, and Testing

    Science.gov (United States)

    Baize, Daniel G. (Editor)

    1999-01-01

    The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Sonic Boom Workshop on September 12-13, 1995. The workshop was designed to bring together NASAs scientists and engineers and their counterparts in industry, other Government agencies, and academia working together in the sonic boom element of NASAs High-Speed Research Program. Specific objectives of this workshop were to: (1) report the progress and status of research in sonic boom propagation, acceptability, and design; (2) promote and disseminate this technology within the appropriate technical communities; (3) help promote synergy among the scientists working in the Program; and (4) identify technology pacing, the development C, of viable reduced-boom High-Speed Civil Transport concepts. The Workshop was organized in four sessions: Sessions 1 Sonic Boom Propagation (Theoretical); Session 2 Sonic Boom Propagation (Experimental); Session 3 Acceptability Studies-Human and Animal; and Session 4 - Configuration Design, Analysis, and Testing.

  16. Chaotic Time Series Analysis Method Developed for Stall Precursor Identification in High-Speed Compressors

    Science.gov (United States)

    1997-01-01

    A new technique for rotating stall precursor identification in high-speed compressors has been developed at the NASA Lewis Research Center. This pseudo correlation integral method uses a mathematical algorithm based on chaos theory to identify nonlinear dynamic changes in the compressor. Through a study of four various configurations of a high-speed compressor stage, a multistage compressor rig, and an axi-centrifugal engine test, this algorithm, using only a single pressure sensor, has consistently predicted the onset of rotating stall.

  17. Dynamics at the Holuhraun eruption based on high speed video data analysis

    Science.gov (United States)

    Witt, Tanja; Walter, Thomas R.

    2016-04-01

    The 2014/2015 Holuhraun eruption was an gas rich fissure eruption with high fountains. The magma was transported by a horizontal dyke over a distance of 45km. At the first day the fountains occur over a distance of 1.5km and focused at isolated vents during the following day. Based on video analysis of the fountains we obtained a detailed view onto the velocities of the eruption, the propagation path of magma, communication between vents and complexities in the magma paths. We collected videos from the Holuhraun eruption with 2 high speed cameras and one DSLR camera from 31st August, 2015 to 4th September, 2015 for several hours. The fountains at adjacent vents visually seemed to be related at all days. Hence, we calculated the height as a function of time from the video data. All fountains show a pulsating regime with apparent and sporadic alternations from meter to several tens of meters heights. By a time-dependent cross-correlation approach developed within the FUTUREVOLC project, we are able to compare the pulses in the height at adjacent vents. We find that in most cases there is a time lag between the pulses. From the calculated time lags between the pulses and the distance between the correlated vents, we calculate the apparent speed of magma pulses. The analysis of the frequency of the fountains and the eruption and rest time between the the fountains itself, are quite similar and suggest a connection and controlling process of the fountains in the feeder below. At the Holuhraun eruption 2014/2015 (Iceland) we find a significant time shift between the single pulses of adjacent vents at all days. The mean velocity of all days is 30-40 km/hr, which could be interpreted by a magma flow velocity along the dike at depth.Comparison of the velocities derived from the video data analysis to the assumed magma flow velocity in the dike based on seismic data shows a very good agreement, implying that surface expressions of pulsating vents provide an insight into the

  18. Sub-surface and surface analysis of high speed machined Ti-6Al-4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez, J.D. Puerta [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Tidu, A., E-mail: tidu@enim.fr [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Bolle, B. [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Chevrier, P. [Laboratoire de Mecanique Biomecanique, Polymere Structures (LaBPS), EA 4632 Ecole Nationale d' Ingenieurs de Metz (ENIM), F-57012 Metz Cedex 01 (France); Fundenberger, J.-J. [Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM), CNRS FRE 3143, Universite Paul Verlaine de Metz (UPVM), F-57012 Metz Cedex 01 (France)

    2010-04-25

    To understand the effects of cutting the surface integrity is an important goal to control the quality of a work piece. The current paper summarizes an extensive experimental study of the surface integrity and the sub-surface microstructure during high speed machining in orthogonal cutting condition. This study includes measurements of residual stresses and crystallographic texture in addition to electron microscopy observations. Our observations and conclusions are primarily focused on the effect of cutting speed considering a set of constant machining parameters on the microstructure evolution of the sub-surface of the material. The results allow a better understanding of the cutting process in high speed machining of titanium alloy Ti-6Al-4V.

  19. 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.

  20. Theoretical and Experimental Aerodynamic Analysis for High-Speed Ground Vehicles

    Science.gov (United States)

    Farhan, Ismail Haider

    Available from UMI in association with The British Library. This thesis investigates the air flow around a proposed geometry for a high-speed electromagnetic suspension (EMS) train. A numerical technique called the panel method has been applied to the representation of the body shape and the prediction of the potential flow and pressure distribution. Two computer programmes have been written, one for a single vehicle in the presence of the ground at different yaw angles, and the second for two-body problems, e.g. a train passing a railway station or a train passing the central part of another train. Two methods based on the momentum integral equations for three-dimensional boundary layer flow have been developed for use with the potential flow analysis; these predict the development of the three-dimensional turbulent boundary layer on the central section (for the analysis of crosswind conditions) and on the nose of the train. Extensive wind tunnel tests were performed on four models of the high-speed train to measure aerodynamic forces, moments and pressures to establish ground effect characteristics. Flow visualisation showed that the wake vortices were stronger and larger in the presence of a ground. At small yaw angles ground clearance had little effect, but as yaw increased, larger ground clearance led to substantial increase in lift and side force coefficients. The tests also identified the differences between a moving and a fixed ground plane. Data showed that the type of ground simulation was significant only in the separated region. A comparison of the results predicted using potential flow theory for an EMS train model and the corresponding results from wind tunnel tests indicated good agreement in regions where the flow is attached. The turbulent boundary layer calculations for the train in a crosswind condition showed that the momentum thickness along the crosswind surface distance co-ordinate increased slowly at the beginning of the development of the

  1. Numerical analysis to determine the impact of land subsidence on high-speed railway routes in Beijing, China

    Science.gov (United States)

    Ye, C.; Yang, Y.; Tian, F.; Luo, Y.; Zhou, Y.

    2015-11-01

    More than 10 high-speed railway routes with top speeds of 300 km h-1 are expected to be operational from Beijing by the year 2020. However, the safety of these routes is affected by the occurrence of land subsidence. This paper focuses on the Beijing-Tianjin Intercity High-Speed Railway (BTR), the first high-speed railway in China, to analyze the operational safety of high-speed railway routes by analyzing both regional land subsidence and local differential subsidence caused by groundwater drawing. The Beijing construction stratum is mainly composed of cohesive soil, and the BTR has a maximum accumulative subsidence of > 800 mm and a maximum subsidence rate of > 80 mm a-1. In this paper, finite-element software ABAQUS is used to analyze groundwater drawdown and land subsidence caused by local water drawing, and its effect on the bearing capacity of railway bridge pile foundations and the orbit concrete supporting course. The analysis provides a technical basis for developing prevention and control engineering measures against land subsidence so as to guarantee the safe operation of these high-speed railway routes.

  2. Analysis of high-speed vessels for Seventh Fleet logistics support

    OpenAIRE

    Morgan, Eric A.

    2005-01-01

    Approved for public release, distribution is unlimited Commander, Logistics Group, Western Pacific (COMLOGWESTPAC) is concerned with the delivery of high priority material, ordnance, and passengers to U.S. Navy ships due to a very large operations area and limited Combat Logistics Force (CLF) assets. High-speed vessels (HSVs) may have the potential to improve the delivery of these materials when used to complement existing logistics shuttle ships. This thesis quantifies current levels of t...

  3. Performance Analysis of High-Speed Deep/Shallow Recessed Hybrid Bearing

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2013-01-01

    Full Text Available The present paper proposes a theoretical analysis of the performance of deep/shallow recessed hybrid bearing. It is intended that, on the basis of the numerical results drawn from this study, appropriate shallow recess depth and width can be determined for use in the bearing design process. By adopting bulk flow theory, the turbulent Reynolds equation and energy equation are modified and solved numerically including concentrated inertia effects at the recess edge with different depth and width of shallow recess. The results indicate that the load capacity, drag torque increases as the depth of shallow recess is shallower and the width ratio (half angle of deep recess versus half angle of shallow recess is smaller. In contrast, the flow rate decreases as the depth of shallow recess is shallower and the width ratio is smaller. Nevertheless, the appropriate design of the depth and width of shallow recess might well induce the performance of high-speed deep/shallow recessed hybrid bearing.

  4. A Selective Change Driven System for High-Speed Motion Analysis

    Directory of Open Access Journals (Sweden)

    Jose A. Boluda

    2016-11-01

    Full Text Available Vision-based sensing algorithms are computationally-demanding tasks due to the large amount of data acquired and processed. Visual sensors deliver much information, even if data are redundant, and do not give any additional information. A Selective Change Driven (SCD sensing system is based on a sensor that delivers, ordered by the magnitude of its change, only those pixels that have changed most since the last read-out. This allows the information stream to be adjusted to the computation capabilities. Following this strategy, a new SCD processing architecture for high-speed motion analysis, based on processing pixels instead of full frames, has been developed and implemented into a Field Programmable Gate-Array (FPGA. The programmable device controls the data stream, delivering a new object distance calculation for every new pixel. The acquisition, processing and delivery of a new object distance takes just 1.7 μ s. Obtaining a similar result using a conventional frame-based camera would require a device working at roughly 500 Kfps, which is far from being practical or even feasible. This system, built with the recently-developed 64 × 64 CMOS SCD sensor, shows the potential of the SCD approach when combined with a hardware processing system.

  5. Analysis of structural dynamic characteristics of a high speed light special catamaran

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper,structural dynamic characteristics of a high-speed light special catamaran-wave piercing catamaran are analyzed using the FEA software MSC-NASTRAN.The dynamic reduction method is introduced to eliminate the local vibration modes in order to obtain the whole ship's mode shapes.In the post-processor,a lot of accessorial methods are adopted to eliminate the local vibrations,so that the whole ship's mode shapes can be identified.The modal analysis indicates that the dynamic reduction method fits for mode shapes identifying.In the end,the test results of a catamaran named Frederick G.Greed are used for reference to validate the obtained results.The comparison process shows that the results are credible.A special mode shape,which is quite different with that of conventional monohull ship,is also pointed out.The obtained results provide a valuable reference for the coming computation of catamaran's vibration characteristics.

  6. 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

  7. 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.

  8. Coordinated analysis of delayed sprites with high-speed images and remote electromagnetic fields

    Science.gov (United States)

    Li, J.; Cummer, S. A.; Lyons, W. A.; Nelson, T. E.

    2008-10-01

    Simultaneous measurements of high-altitude optical emissions and magnetic fields produced by sprite-associated lightning discharges enable a close examination of the link between low-altitude lightning processes and high-altitude sprite processes. We report results of the coordinated analysis of high-speed sprite video and wideband magnetic field measurements recorded simultaneously at Yucca Ridge Field Station and Duke University. From June to August 2005, sprites were detected following 67 lightning strokes, all of which had positive polarity. Our data showed that 46% of the 83 discrete sprite events in these sequences initiated more than 10 ms after the lightning return stroke, and we focus on these delayed sprites in this work. All delayed sprites were preceded by continuing current moments that averaged at least 11 kA km between the return stroke and sprites. The total lightning charge moment change at sprite initiation varied from 600 to 18,600 C km, and the minimum value to initiate long-delayed sprites ranged from 600 for 15 ms delay to 2000 C km for more than 120 ms delay. We numerically simulated electric fields at altitudes above these lightning discharges and found that the maximum normalized electric fields are essentially the same as fields that produce short-delayed sprites. Both estimated and simulation-predicted sprite initiation altitudes indicate that long-delayed sprites generally initiate around 5 km lower than short-delayed sprites. The simulation results also reveal that slow (5-20 ms) intensifications in continuing current can play a major role in initiating delayed sprites.

  9. 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.

  10. ADAPTIVE DELAUNAY TRIANGULATION WITH MULTIDIMENSIONAL DISSIPATION SCHEME FOR HIGH-SPEED COMPRESSIBLE FLOW ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Adaptive Delaunay triangulation is combined with the cell-centered upwinding algorithm to analyze inviscid high-speed compressible flow problems. The multidimensional dissipation scheme was developed and included in the upwinding algorithm for unstructured triangular meshes to improve the computed shock wave resolution. The solution accuracy is further improved by coupling an error estimation procedure to a remeshing algorithm that generates small elements in regions with large change of solution gradients, and at the same time, larger elements in other regions. The proposed scheme is further extended to achieve higher-order spatial and temporal solution accuracy. Efficiency of the combined procedure is evaluated by analyzing supersonic shocks and shock propagation behaviors for both the steady and unsteady high-speed compressible flows.

  11. Linearity Analysis on a Series-Split Capacitor Array for High-Speed SAR ADCs

    Directory of Open Access Journals (Sweden)

    Yan Zhu

    2010-01-01

    Full Text Available A novel Capacitor array structure for Successive Approximation Register (SAR ADC is proposed. This circuit efficiently utilizes charge recycling to achieve high-speed of operation and it can be applied to high-speed and low-to-medium-resolution SAR ADC. The parasitic effects and the static linearity performance, namely, the INL and DNL, of the proposed structure are theoretically analyzed and behavioral simulations are performed to demonstrate its effectiveness under those nonidealities. Simulation results show that to achieve the same conversion performance the proposed capacitor array structure can reduce the average power consumed from the reference ladder by 90% when compared to the binary-weighted splitting capacitor array structure.

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

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

  13. High-speed AC motors

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  14. FINITE ELEMENT ANALYSIS FOR CHIP FORMATION IN HIGH SPEED TURNING OPERATIONS BY ARBITRARY LAGRANGIAN EULERIAN METHOD

    Institute of Scientific and Technical Information of China (English)

    USAMA Umer; XIE Lijing; WANG Xibin

    2006-01-01

    A two-dimensional finite element (FE) model for the high speed turning operations when orthogonally machining AISI H13 tool steel at 49HRC using poly crystalline cubic boron nitride(PCBN) is described. An arbitrary Lagrangian Eulerian (ALE) method has been adopted which does not need any chip separation criteria as opposed to the traditional Lagrangian approach. Through FE simulations temperature and stresses distributions are presented that could be helpful in predicting tool life and improving process parameters. The results show that high temperatures are generated along the tool rake face as compared to the shear zone temperatures due to high thermal conductivity of PCBN tools.

  15. Analysis of electromagnetic field emitted from home plug power line used for indoor high-speed broadband communication

    Institute of Scientific and Technical Information of China (English)

    Yong XU; Yinghua LV; Biao YANG; Hongxin ZHANG

    2009-01-01

    High-speed broadband power line communication (BPL) is a novel and practicable technique for NetatHome or home area local area networking (LAN).Because of the characteristics of BPL, the electromagnetic wave emitted from the BPL transmission media will influence the indoor electromagnetic environment, which would also affect the performance of other wireless communications. Based on the analysis of the communication channel characteristic, network impedance and attenuation characteristic of the BPL, this paper proposes a novel model for calculating the BPL radiation and the computer simulation model, which are proved by the coherence of the simulation and the test data. The interferences from the high-speed BPL to indoor wireless communications are analyzed to stipulate the standards of high-speed BPL in the future.

  16. Automated high-speed video analysis of the bubble dynamics in subcooled flow boiling

    Energy Technology Data Exchange (ETDEWEB)

    Maurus, Reinhold; Ilchenko, Volodymyr; Sattelmayer, Thomas [Technische Univ. Muenchen, Lehrstuhl fuer Thermodynamik, Garching (Germany)

    2004-04-01

    Subcooled flow boiling is a commonly applied technique for achieving efficient heat transfer. In the study, an experimental investigation in the nucleate boiling regime was performed for water circulating in a closed loop at atmospheric pressure. The test-section consists of a rectangular channel with a one side heated copper strip and a very good optical access. For the optical observation of the bubble behaviour the high-speed cinematography is used. Automated image processing and analysis algorithms developed by the authors were applied for a wide range of mass flow rates and heat fluxes in order to extract characteristic length and time scales of the bubbly layer during the boiling process. Using this methodology, a huge number of bubble cycles could be analysed. The structure of the developed algorithms for the detection of the bubble diameter, the bubble lifetime, the lifetime after the detachment process and the waiting time between two bubble cycles is described. Subsequently, the results from using these automated procedures are presented. A remarkable novelty is the presentation of all results as distribution functions. This is of physical importance because the commonly applied spatial and temporal averaging leads to a loss of information and, moreover, to an unjustified deterministic view of the boiling process, which exhibits in reality a very wide spread of bubble sizes and characteristic times. The results show that the mass flux dominates the temporal bubble behaviour. An increase of the liquid mass flux reveals a strong decrease of the bubble life - and waiting time. In contrast, the variation of the heat flux has a much smaller impact. It is shown in addition that the investigation of the bubble history using automated algorithms delivers novel information with respect to the bubble lift-off probability. (Author)

  17. Comparative Analysis of the Separation Variation Influence on the Hydrodynamic Performance of a High Speed Trimaran

    Institute of Scientific and Technical Information of China (English)

    Khaled Hafez; Abdel-Rahman El-Kot

    2011-01-01

    This paper numerically investigates the influence of separation variation of the outriggers on the hydrodynamic performance of a high speed trimaran(HST)aiming at improving its applicability in diverse realistic disciplines.The present investigation was performed within the framework of the 2-D slender body method(SBM)by calculating the resistance of three symmetric trimaran series moving in a calm free surface of deep water.Each trimaran series comprises of 4681 configurations generated by considering 151 staggers (-50%≤α≤+ 100%),and 31 separations(100%≤β≤400%)for 81 Froude numbers(0.20≤Fn≤1.0).In developingthe three trimaran series,Wigley(C)-st,AMECRC(C)-09,and NPL(C)-4a models were used separately for both the main and side hulls of each individual series models.A computer macro named Tri-PL(C)was created using the Visual Basic for Applications(C).Tri-PL(C)sequentially interfaced Maxsurf(C)then Hullspeed(C)to generate the models of the three trimaran series together with their detailed hydrostatic particulars,followed by their resistance components.The numerical results were partially validated against the available published numerical calculations and experimental results,to benchmark the Tri-PL(C)macro and hence to rely on the analysis outcomes.A graph template was created within the framework of SigmaPlot(C)to visualize the significant results of the Tri-PL(C)properly.

  18. 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.

  19. Eulerian frequency analysis of structural vibrations from high-speed video

    Science.gov (United States)

    Venanzoni, Andrea; De Ryck, Laurent; Cuenca, Jacques

    2016-06-01

    An approach for the analysis of the frequency content of structural vibrations from high-speed video recordings is proposed. The techniques and tools proposed rely on an Eulerian approach, that is, using the time history of pixels independently to analyse structural motion, as opposed to Lagrangian approaches, where the motion of the structure is tracked in time. The starting point is an existing Eulerian motion magnification method, which consists in decomposing the video frames into a set of spatial scales through a so-called Laplacian pyramid [1]. Each scale - or level - can be amplified independently to reconstruct a magnified motion of the observed structure. The approach proposed here provides two analysis tools or pre-amplification steps. The first tool provides a representation of the global frequency content of a video per pyramid level. This may be further enhanced by applying an angular filter in the spatial frequency domain to each frame of the video before the Laplacian pyramid decomposition, which allows for the identification of the frequency content of the structural vibrations in a particular direction of space. This proposed tool complements the existing Eulerian magnification method by amplifying selectively the levels containing relevant motion information with respect to their frequency content. This magnifies the displacement while limiting the noise contribution. The second tool is a holographic representation of the frequency content of a vibrating structure, yielding a map of the predominant frequency components across the structure. In contrast to the global frequency content representation of the video, this tool provides a local analysis of the periodic gray scale intensity changes of the frame in order to identify the vibrating parts of the structure and their main frequencies. Validation cases are provided and the advantages and limits of the approaches are discussed. The first validation case consists of the frequency content

  20. Analysis and Comparison of Modular Railway Power Conditioner for High-Speed Railway Traction System

    DEFF Research Database (Denmark)

    Xu, Qianming; Ma, Fujun; He, Zhixing

    2017-01-01

    With the rapid development of modern electrified railway, negative sequence current (NSC) minimization is one of the most important considerations in the high-speed railway traction system. In the past, many multiple or multilevel topologies with high compensation capacity have been introduced...... for railway power conditioner (RPC). This paper presents a simplified quantitative comparison of five previous modular RPC topologies for negative sequence compensation in V/V and SCOTT traction systems, aiming for an optimal selection of the compensators. Performance criteria such as transformer requirement...

  1. Development of High Speed Imaging and Analysis Techniques Compressible Dynamics Stall

    Science.gov (United States)

    Chandrasekhara, M. S.; Carr, L. W.; Wilder, M. C.; Davis, Sanford S. (Technical Monitor)

    1996-01-01

    parameters on the dynamic stall process. When interferograms can be captured in real time, the potential for real-time mapping of a developing unsteady flow such as dynamic stall becomes a possibility. This has been achieved in the present case through the use of a high-speed drum camera combined with electronic circuitry which has resulted in a series of interferograms obtained during a single cycle of dynamic stall; images obtained at the rate of 20 KHz will be presented as a part of the formal presentation. Interferometry has been available for a long time; however, most of its use has been limited to visualization. The present research has focused on use of interferograms for quantitative mapping of the flow over oscillating airfoils. Instantaneous pressure distributions can now be obtained semi-automatically, making practical the analysis of the thousands of interferograms that are produced in this research. A review of the techniques that have been developed as part of this research effort will be presented in the final paper.

  2. 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.

  3. Wideband Radar Echo Frequency-domain Simulation and Analysis for High Speed Moving Targets

    Directory of Open Access Journals (Sweden)

    Ning Chao

    2014-04-01

    Full Text Available A frequency-domain method is proposed for wideband radar echo simulation of high-speed moving targets. Based on the physical process of electromagnetic waves observing a moving target, a frequency-domain echo model of wideband radar is constructed, and the block diagram of the radar echo simulation in frequency-domain is presented. Then, the impacts of radial velocity and slant range on the matching filtering of LFM radar are analyzed, and some quantitative conclusions on the shift and expansion of the radar profiles are obtained. Simulation results illustrate the correctness and efficiency of the proposed method.

  4. Structural strength analysis and fatigue life prediction of traction converter box in high-speed EMU

    Science.gov (United States)

    Tan, Qin; Li, Qiang

    2017-01-01

    The method of building the FEA model of traction converter box in high-speed EMU and analyzing the static strength and fatigue strength of traction converter box based on IEC 61373-2010 and EN 12663 standards is presented in this paper. The load-stress correlation coefficients of weak points is obtained by FEA model, applied to transfer the load history of traction converter box to stress history of each point. The fatigue damage is calculated based on Miner's rule and the fatigue life of traction converter box is predicted. According to study, the structural strength of traction converter box meets design requirements.

  5. 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...

  6. Monitoring and analysis of thermal deformation waves with a high-speed phase measurement system.

    Science.gov (United States)

    Taylor, Lucas; Talghader, Joseph

    2015-10-20

    Thermal effects in optical substrates are vitally important in determining laser damage resistance in long-pulse and continuous-wave laser systems. Thermal deformation waves in a soda-lime-silica glass substrate have been measured using high-speed interferometry during a series of laser pulses incident on the surface. Two-dimensional images of the thermal waves were captured at a rate of up to six frames per thermal event using a quantitative phase measurement method. The system comprised a Mach-Zehnder interferometer, along with a high-speed camera capable of up to 20,000 frames-per-second. The sample was placed in the interferometer and irradiated with 100 ns, 2 kHz Q-switched pulses from a high-power Nd:YAG laser operating at 1064 nm. Phase measurements were converted to temperature using known values of thermal expansion and temperature-dependent refractive index for glass. The thermal decay at the center of the thermal wave was fit to a function derived from first principles with excellent agreement. Additionally, the spread of the thermal distribution over time was fit to the same function. Both the temporal decay fit and the spatial fit produced a thermal diffusivity of 5×10-7  m2/s.

  7. Air flow patterns and noise analysis inside high speed angular contact ball bearings

    Institute of Scientific and Technical Information of China (English)

    翟强; 闫柯; 张优云; 朱永生; 王亚泰

    2015-01-01

    The vortex formed around the rolling ball and the high pressure region formed around the ball−raceway contact zone are the principle factors that barricades the lubricant entering the bearing cavity, and further causes improper lubrication. The investigation of the air phase flow inside the bearing cavity is essential for the optimization of the oil−air two-phase lubrication method. With the revolutionary reference frame describing the bearing motion, a highly precise air phase flow model inside the angular contact ball bearing cavity was build up. Comprehensive factors such as bearing revolution, ball rotation, and cage structure were considered to investigate the influences on the air phase flow and heat transfer efficiency. The aerodynamic noise was also analyzed. The result shows that the ball spinning leads to the pressure rise and uneven pressure distribution. The air phase velocity, pressure and cage heat transfer efficiency increase as the revolving speed increases. The operating noise is largely due to the impact of the high speed external flow on the bearing. When the center of the oil−air outlet fixes near the inner ring, the aerodynamic noise is reduced. The position near the inner ring on the bigger axial side is the ideal position to fix the lubricating device for the angular contact ball bearing.

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

    Institute of Scientific and Technical Information of China (English)

    ZHAO ZhengMing; BAI Hua; YUAN LiQiang

    2009-01-01

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

  9. Observation and analysis of high-speed human motion with frequent occlusion in a large area

    Science.gov (United States)

    Wang, Yuru; Liu, Jiafeng; Liu, Guojun; Tang, Xianglong; Liu, Peng

    2009-12-01

    The use of computer vision technology in collecting and analyzing statistics during sports matches or training sessions is expected to provide valuable information for tactics improvement. However, the measurements published in the literature so far are either unreliably documented to be used in training planning due to their limitations or unsuitable for studying high-speed motion in large area with frequent occlusions. A sports annotation system is introduced in this paper for tracking high-speed non-rigid human motion over a large playing area with the aid of motion camera, taking short track speed skating competitions as an example. The proposed system is composed of two sub-systems: precise camera motion compensation and accurate motion acquisition. In the video registration step, a distinctive invariant point feature detector (probability density grads detector) and a global parallax based matching points filter are used, to provide reliable and robust matching across a large range of affine distortion and illumination change. In the motion acquisition step, a two regions' relationship constrained joint color model and Markov chain Monte Carlo based joint particle filter are emphasized, by dividing the human body into two relative key regions. Several field tests are performed to assess measurement errors, including comparison to popular algorithms. With the help of the system presented, the system obtains position data on a 30 m × 60 m large rink with root-mean-square error better than 0.3975 m, velocity and acceleration data with absolute error better than 1.2579 m s-1 and 0.1494 m s-2, respectively.

  10. High Speed Exit Taxiways.

    Science.gov (United States)

    1981-02-01

    E -4 ’ i ~.1 ’i -i C; aa fillli -4i E E c ACKNOWLEDGEMENT This report is an edited version of the work undertaken by Max H. Coggins , Ronald B...type. (Ref. d) 2.1.4 The NASA Langley Terminal Configured Vehicle (TCV) program c:nduct,2 aircraft operational tests , collected data, and performed...analysis to demonstrate the feasibility of markedly increasing the air carrier aircraft arrival acceptance tate of suitably designed airport runways. Tests

  11. Quantitative analysis of vocal fold vibration during register change by high-speed digital imaging system

    Science.gov (United States)

    Kumada, Masanobu; Kobayashi, Noriko; Hirose, Hajime; Tayama, Niro; Imagawa, Hiroshi; Sakakibara, Ken-Ichi; Nito, Takaharu; Kakurai, Shin'ichi; Kumada, Chieko; Wada, Mamiko; Niimi, Seiji

    2002-05-01

    The physiological study of prosody is indispensable in terms not only of the physiological interest but also of the evaluation and treatment for pathological cases of prosody. In free talk, the changes of vocal fold vibration are found frequently and these phenomena are very important prosodic events. To analyze quantitatively the vocal fold vibration at the register change as the model of prosodic event, our high-speed digital imaging system was used at a rate of 4500 images of 256-256 pixels per second. Four healthy Japanese adults (2 males and 2 females) were served as subjects. Tasks were sustained phonation containing register changes. Two major categories (Category A and B) were found in the ways of changing of vocal fold vibrations at the register change. In Category A, changes were very smooth in terms of the vocal fold vibration. In Category B, changes were not so smooth with some additional events at the register change, such as the anterior-posterior phase difference of the vibration, the abduction of the vocal folds, or the interruption of the phonation. The number of the subtypes for Category B is thought to increase if more subjects with a wider range of variety are analyzed. For the study of prosody, our high-speed digital imaging system is a very powerful tool by which physiological information can be obtained.

  12. 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

  13. 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.

  14. 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

  15. High-speed imaging optical techniques for shockwave and droplets atomization analysis

    Science.gov (United States)

    Slangen, Pierre R.; Lauret, Pierre; Heymes, Frederic; Aprin, Laurent; Lecysyn, Nicolas

    2016-12-01

    Droplets atomization by shockwave can act as a consequence in domino effects on an industrial facility: aggression of a storage tank (projectile from previous event, for example) can cause leakage of hazardous material (toxic and flammable). As the accident goes on, a secondary event can cause blast generation, impacting the droplets and resulting in their atomization. Therefore, exchange surface increase impacts the evaporation rate. This can be an issue in case of dispersion of such a cloud. The experiments conducted in the lab generate a shockwave with an open-ended shock tube to break up liquid droplets. As the expected shockwave speed is about 400 m/s (˜Mach 1.2), the interaction with falling drops is very short. High-speed imaging is performed at about 20,000 fps. The shockwave is measured using both overpressure sensors: particle image velocimetry and pure in line shadowgraphy. The size of fragmented droplets is optically measured by direct shadowgraphy simultaneously in different directions. In these experiments, secondary breakups of a droplet into an important number of smaller droplets from the shockwave-induced flow are shown. The results of the optical characterizations are discussed in terms of shape, velocity, and size.

  16. Structure Design and Performance Analysis of High-Speed Miniature Ball Bearing

    Science.gov (United States)

    Li, Songsheng; Zhang, Guoye; Chen, Bin; Shen, Yuan

    2017-07-01

    The working performances of miniature ball bearings are obviously affected by its’ geometric structure parameters. In this paper, quasi-static analysis theory is applied in the design of miniature ball bearings. Firstly, it is studied the influence of geometry structure, preload and rotating speed on the dynamic performance of bearing. Secondly, bearing dynamic characteristics are analyzed which include the bearing stiffness and Spin to roll Ratio. Lastly, the contact stress and bearing life are calculated. The results indicate that structure parameters play an importance role in bearing’s dynamic performances. Miniature ball bearings which have lager ball number, bigger ball diameter and smaller inner race groove radius can get better performances while velocity and preload have great impact on the bearing life. So that parameters of miniature bearing should be chosen cautiously.

  17. 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.

  18. 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.

  19. Analysis of droplet transfer of pulsed MIG welding based on electrical signal and high-speed photography

    Institute of Scientific and Technical Information of China (English)

    YAO Ping; XUE Jiaxiang; HUANG Wenchao; ZHANG Rui

    2009-01-01

    In order to study how welding parameters affect welding quality and droplet transfer, a synchronous acquisition and analysis system is established to acquire and analyze electrical signal and instantaneous images of droplet transfer simultaneously, which is based on a self-developed soft-switching inverter. On the one hand, welding current and voltage signals are acquired and analyzed by a self-developed dynamic wavelet analyzer. On the other hand, images are filtered and optimized after they are captured by high-speed camera. The results show that instantaneous waveforms and statistical data of electrical signal contribute to make an overall assessment of welding quality, and that optimized high-speed images allow a visual and clear observation of droplet transfer process. The analysis of both waveforms and images leads to a further research on droplet transfer mechanism and provides a basis for precise control of droplet transfer.

  20. Theoretical Analysis of Stationary Potential Flows and Boundary Layers at High Speed

    Science.gov (United States)

    Oswaititsch, K.; Wieghardt, K.

    1948-01-01

    The present report consists of two parts. The first part deals with the two-dimensional stationary flow in the presence of local supersonic zones. A numerical method of integration of the equation of gas dynamics is developed. Proceeding from solutions at great distance from the body the flow pattern is calculated step by step. Accordingly the related body form is obtained at the end of the calculation. The second part treats the relationship between the displacement thickness of laminar and turbulent boundary layers and the pressure distribution at high speeds. The stability of the boundary layer is investigated, resulting in basic differences in the behavior of subsonic and supersonic flows. Lastly, the decisive importance of the boundary layer for the pressure distribution, particularly for thin profiles, is demonstrated.

  1. An experimental analysis of a vibrating guitar string using high-speed photography

    Science.gov (United States)

    Whitfield, Scott B.; Flesch, Kurt B.

    2014-02-01

    We use high-speed photography (1200 frames/s) to investigate the vibrational motion of a plucked guitar string over several cycles. We investigate the vibrational pattern for plucking the string at two different locations along the string's length, and with different initial amplitudes. The vibrational patterns are then compared to a standing wave model of the string vibrations. We find excellent agreement between the observed vibrational patterns and the model for small-initial-amplitude displacement of the string. For larger amplitude displacements, the qualitative behavior of the string's vibrational pattern differs significantly from the small-amplitude displacement. This behavior may be due to the presence of inharmonicity, as suggested by its incorporation into the model calculations.

  2. Simulation and analysis of aerodynamics for high speed face milling cutters

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In high speed face milling,noise can be broadly categorized as idling noise and cutting noise.Idling noise mainly consists of aerodynamic noise.A mathematical model is developed based on the Ffowcs Williams-Hawkings Equation.The noise predicted with the mathematical model compares well with the experimental observations.The characteristics of aerodynamic noise with the different model parameters (number of teeth,tooth spacing) and locations of observation points are investigated.The directivity of noise is found and the peak value of sound power can be moved from the rotating frequency to higher frequency.This investigation can provide theoretical foundation for the design of face milling cutters with low noise.

  3. 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.

  4. Terminal Performance of Lead Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

    Science.gov (United States)

    2016-04-04

    2013) and Keys et al. (2015) were applied on a number of different lead- free bullet loads. Rounds in 9mm NATO, .357 SIG, and .40 S&W were fired...encountered shot angles . This bullet also fails to meet the FBI recommended minimum penetration depth of 12 inches for duty use. Figure 4: Retarding...Terminal Performance of Lead- Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video ELIJAH COURTNEY, AMY

  5. Velo and REXAN - Integrated Data Management and High Speed Analysis for Experimental Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kleese van Dam, Kerstin; Carson, James P.; Corrigan, Abigail L.; Einstein, Daniel R.; Guillen, Zoe C.; Heath, Brandi S.; Kuprat, Andrew P.; Lanekoff, Ingela T.; Lansing, Carina S.; Laskin, Julia; Li, Dongsheng; Liu, Yan; Marshall, Matthew J.; Miller, Erin A.; Orr, Galya; Pinheiro da Silva, Paulo; Ryu, Seun; Szymanski, Craig J.; Thomas, Mathew

    2013-01-10

    The Chemical Imaging Initiative at the Pacific Northwest National Laboratory (PNNL) is creating a ‘Rapid Experimental Analysis’ (REXAN) Framework, based on the concept of reusable component libraries. REXAN allows developers to quickly compose and customize high throughput analysis pipelines for a range of experiments, as well as supporting the creation of multi-modal analysis pipelines. In addition, PNNL has coupled REXAN with its collaborative data management and analysis environment Velo to create an easy to use data management and analysis environments for experimental facilities. This paper will discuss the benefits of Velo and REXAN in the context of three examples: PNNL High Resolution Mass Spectrometry - reducing analysis times from hours to seconds, and enabling the analysis of much larger data samples (100KB to 40GB) at the same time · ALS X-Ray tomography - reducing analysis times of combined STXM and EM data collected at the ALS from weeks to minutes, decreasing manual work and increasing data volumes that can be analysed in a single step ·Multi-modal nano-scale analysis of STXM and TEM data - providing a semi automated process for particle detection The creation of REXAN has significantly shortened the development time for these analysis pipelines. The integration of Velo and REXAN has significantly increased the scientific productivity of the instruments and their users by creating easy to use data management and analysis environments with greatly reduced analysis times and improved analysis capabilities.

  6. 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

  7. Characterization and Analysis of Integrated Silicon Photonic Detectors for High-Speed Communications

    Science.gov (United States)

    2015-03-26

    devices. This document describes the characterization and analysis of inte- grated photodiodes for digital and analog applications. The photodiode is...50 LCR inductance , capacitance, and resistance . . . . . . . . . . . . . . . . . . . . . . . 52 TE transverse electric...application for the high-bandwidth capability of integrated pho- tonic systems, could be used for analog antenna remoting. By up-converting to a high

  8. New measuring concepts using integrated online analysis of color and monochrome digital high-speed camera sequences

    Science.gov (United States)

    Renz, Harald

    1997-05-01

    High speed sequences allow a subjective assessment of very fast processes and serve as an important basis for the quantitative analysis of movements. Computer systems help to acquire, handle, display and store digital image sequences as well as to perform measurement tasks automatically. High speed cameras have been used since several years for safety tests, material testing or production optimization. To get the very high speed of 1000 or more images per second, three have been used mainly 16 mm film cameras, which could provide an excellent image resolution and the required time resolution. But up to now, most results have been only judged by viewing. For some special applications like safety tests using crash or high-g sled tests in the automobile industry there have been used image analyzing techniques to measure also the characteristic of moving objects inside images. High speed films, shot during the short impact, allow judgement of the dynamic scene. Additionally they serve as an important basis for the quantitative analysis of the very fast movements. Thus exact values of the velocity and acceleration, the dummies or vehicles are exposed to, can be derived. For analysis of the sequences the positions of signalized points--mostly markers, which are fixed by the test engineers before a test--have to be measured frame by frame. The trajectories show the temporal sequence of the test objects and are the base for calibrated diagrams of distance, velocity and acceleration. Today there are replaced more and more 16 mm film cameras by electronic high speed cameras. The development of high-speed recording systems is very far advanced and the prices of these systems are more and more comparable to those of traditional film cameras. Also the resolution has been increased very greatly. The new cameras are `crashproof' and can be used for similar tasks as the 16 mm film cameras at similar sizes. High speed video cameras now offer an easy setup and direct access to

  9. 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

  10. Simulink models for performance analysis of high speed DQPSK modulated optical link

    Science.gov (United States)

    Sharan, Lucky; Rupanshi, Chaubey, V. K.

    2016-03-01

    This paper attempts to present the design approach for development of simulation models to study and analyze the transmission of 10 Gbps DQPSK signal over a single channel Peer to Peer link using Matlab Simulink. The simulation model considers the different optical components used in link design with their behavior represented initially by theoretical interpretation, including the transmitter topology, Mach Zehnder Modulator(MZM) module and, the propagation model for optical fibers etc. thus allowing scope for direct realization in experimental configurations. It provides the flexibility to incorporate the various photonic components as either user-defined or fixed and, can also be enhanced or removed from the model as per the design requirements. We describe the detailed operation and need of every component model and its representation in Simulink blocksets. Moreover the developed model can be extended in future to support Dense Wavelength Division Multiplexing (DWDM) system, thereby allowing high speed transmission with N × 40 Gbps systems. The various compensation techniques and their influence on system performance can be easily investigated by using such models.

  11. Nonlinear dynamic analysis and optimal trajectory planning of a high-speed macro-micro manipulator

    Science.gov (United States)

    Yang, Yi-ling; Wei, Yan-ding; Lou, Jun-qiang; Fu, Lei; Zhao, Xiao-wei

    2017-09-01

    This paper reports the nonlinear dynamic modeling and the optimal trajectory planning for a flexure-based macro-micro manipulator, which is dedicated to the large-scale and high-speed tasks. In particular, a macro- micro manipulator composed of a servo motor, a rigid arm and a compliant microgripper is focused. Moreover, both flexure hinges and flexible beams are considered. By combining the pseudorigid-body-model method, the assumed mode method and the Lagrange equation, the overall dynamic model is derived. Then, the rigid-flexible-coupling characteristics are analyzed by numerical simulations. After that, the microscopic scale vibration excited by the large-scale motion is reduced through the trajectory planning approach. Especially, a fitness function regards the comprehensive excitation torque of the compliant microgripper is proposed. The reference curve and the interpolation curve using the quintic polynomial trajectories are adopted. Afterwards, an improved genetic algorithm is used to identify the optimal trajectory by minimizing the fitness function. Finally, the numerical simulations and experiments validate the feasibility and the effectiveness of the established dynamic model and the trajectory planning approach. The amplitude of the residual vibration reduces approximately 54.9%, and the settling time decreases 57.1%. Therefore, the operation efficiency and manipulation stability are significantly improved.

  12. 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.

  13. Simulink models for performance analysis of high speed DQPSK modulated optical link

    Energy Technology Data Exchange (ETDEWEB)

    Sharan, Lucky, E-mail: luckysharan@pilani.bits-pilani.ac.in; Rupanshi,, E-mail: f2011222@pilani.bits-pilani.ac.in; Chaubey, V. K., E-mail: vkc@pilani.bits-pilani.ac.in [EEE Department, BITS-Pilani, Rajasthan, 333031 (India)

    2016-03-09

    This paper attempts to present the design approach for development of simulation models to study and analyze the transmission of 10 Gbps DQPSK signal over a single channel Peer to Peer link using Matlab Simulink. The simulation model considers the different optical components used in link design with their behavior represented initially by theoretical interpretation, including the transmitter topology, Mach Zehnder Modulator(MZM) module and, the propagation model for optical fibers etc. thus allowing scope for direct realization in experimental configurations. It provides the flexibility to incorporate the various photonic components as either user-defined or fixed and, can also be enhanced or removed from the model as per the design requirements. We describe the detailed operation and need of every component model and its representation in Simulink blocksets. Moreover the developed model can be extended in future to support Dense Wavelength Division Multiplexing (DWDM) system, thereby allowing high speed transmission with N × 40 Gbps systems. The various compensation techniques and their influence on system performance can be easily investigated by using such models.

  14. 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...

  15. Analysis of ependymal ciliary beat pattern and beat frequency using high speed imaging: comparison with the photomultiplier and photodiode methods

    Directory of Open Access Journals (Sweden)

    O'Callaghan Chris

    2012-06-01

    Full Text Available Abstract Background The aim of this study was to compare beat frequency measurements of ependymal cilia made by digital high speed imaging to those obtained using the photomultiplier and modified photodiode techniques. Using high speed video analysis the relationship of the power and recover strokes was also determined. Methods Ciliated strips of ependyma attached to slices from the brain of Wistar rats were incubated at 30°C and observed using a ×50 water immersion lens. Ciliary beat frequency was measured using each of the three techniques: the high speed video, photodiode and photomultiplier. Readings were repeated after 30 minutes incubation at 37°C. Ependymal cilia were observed in slow motion and the precise movement of cilia during the recovery stroke relative to the path travelled during the power stroke was measured. Results The mean (95% confidence intervals beat frequencies determined by the high speed video, photomultiplier and photodiode at 30°C were 27.7 (26.6 to 28.8, 25.5 (24.4 to 26.6 and 20.8 (20.4 to 21.3 Hz, respectively. The mean (95% confidence intervals beat frequencies determined by the high speed video, photomultiplier and photodiode at 37°C were 36.4 (34 to 39.5, 38.4 (36.8 to 39.9 and 18.8 (16.9 to 20.5 Hz. The inter and intra observer reliability for measurement of ciliary beat frequency was 3.8% and 1%, respectively. Ependymal cilia were observed to move in a planar fashion during the power and recovery strokes with a maximum deviation to the right of the midline of 12.1(11.8 to 13.0° during the power stroke and 12.6(11.6 to 13.6° to the left of the midline during the recovery stroke. Conclusion The photodiode technique greatly underestimates ciliary beat frequency and should not be used to measure ependymal ciliary beat frequency at the temperatures studied. Ciliary beat frequency from the high speed video and photomultiplier techniques cannot be used interchangeably. Ependymal cilia had minimal deviation to

  16. 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

  17. 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.

  18. Analysis of the monitoring data of geomagnetic storm interference in the electrification system of a high-speed railway

    Science.gov (United States)

    Liu, Lianguang; Ge, Xiaoning; Zong, Wei; Zhou, You; Liu, Mingguang

    2016-10-01

    To study the impact of geomagnetic storm on the equipment of traction electrification system in the high-speed railway, geomagnetically induced current (GIC) monitoring devices were installed in the Hebi East traction power supply substation of the Beijing-Hong Kong Dedicated Passenger Line in January 2015, and GICs were captured during the two geomagnetic storms on 17 March and 23 June 2015. In order to investigate the GIC flow path, both in the track circuit and in the traction network adopting the autotransformer feeding system, a GIC monitor plan was proposed for the electrical system in the Hebi East traction power supply substation. This paper analyzes the correlation between the GIC captured on 17 March and the geomagnetic data obtained from the Malingshan Geomagnetic Observatory and presents a regression analysis between the measured GIC and the calculated geoelectric fields on 23 June in the high-speed railway. The maximum GICs measured in the track circuit are 1.08 A and 1.74 A during the two geomagnetic storms. We find that it is necessary to pay attention on the throttle transformers and track circuits, as the most sensitive elements responding to the extreme geomagnetic storms in the high-speed railway.

  19. The Analysis of the High Speed Wire Drawing Process of High Carbon Steel Wires Under Hydrodynamic Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Suliga M.

    2015-04-01

    Full Text Available In this work the analysis of the wire drawing process in hydrodynamic dies has been done. The drawing process of φ5.5 mm wire rod to the final wire of φ1.7 mm was conducted in 12 passes, in drawing speed range of 5-25 m/s. For final wires of φ1.7 mm the investigation of topography of wire surface, the amount of lubricant on the wire surface and the pressure of lubricant in hydrodynamic dies were determined. Additionally, in the work selected mechanical properties of the wires have been estimated.

  20. The Analysis of the High Speed Wire Drawing Process of High Carbon Steel Wires Under Hydrodynamic Lubrication Conditions

    OpenAIRE

    Suliga M.

    2015-01-01

    In this work the analysis of the wire drawing process in hydrodynamic dies has been done. The drawing process of φ5.5 mm wire rod to the final wire of φ1.7 mm was conducted in 12 passes, in drawing speed range of 5-25 m/s. For final wires of φ1.7 mm the investigation of topography of wire surface, the amount of lubricant on the wire surface and the pressure of lubricant in hydrodynamic dies were determined. Additionally, in the work selected mechanical properties of the wires have been estima...

  1. Structural analysis and design of frost resistance function for subgrade of high-speed railway ballasted track in cold regions

    Institute of Scientific and Technical Information of China (English)

    Qiang Luo; WenQiang Lv; QingZhi Ye; RuiGuo Zhang

    2015-01-01

    According to the technical characteristics of short fixed wheelbase of a high-speed carriage, a subgrade-track integrated space mechanical response analysis model is proposed for trains under the action of biaxial load after the comparison of the stress distribution characteristics of the ballast track subgrade bed structures for high-speed railway under the action of uniaxial load and biaxial load. The loading threshold value (high-cycle long-term dynamic strength) under the circum-stance where the cumulative deformation of subgrade structure gradually develops and finally reaches the convergent state, and its relationship with the foundation coefficient K30 were deduced, based on the characteristics of cumulative defor-mation evolution obtained from the unit structure filling model test under the action of cyclic loading. In view of structure stability and frost resistance requirements of the railway subgrade in cold regions, technical conditions to maintain good service performance of subgrade structure of high-speed railway ballasted track are discussed and analyzed. Study results show that the additive effect manifests itself obviously for railway train bogies under the action of biaxial load than uni-axial load, which has a significant dynamic effect on the subgrade bed bottom and a slight effect on the surface layer. Thus, the adoption of a biaxial load model in the design of a high-speed railway subgrade accurately reflects the vehicle load. Pursuant to the structure design principle, the design method of the subgrade structure of high-speed railway ballasted track is proposed to meet the technical requirements such as structural strength, bearing stiffness and high-cyclic and long-term stability. Technical indicators are obtained for the variation of thickness of the surface layer of reinforced sub-grade bed in the double-layer subgrade mode along with the change of K30 at the subgrade bed bottom. The double-layer structure mode of"closure on the upper

  2. Development of A Super High Speed Permanent Magnet Synchronous Motor (PMSM Controller and Analysis of The Experimental Results

    Directory of Open Access Journals (Sweden)

    Limei Zhao

    2005-02-01

    Full Text Available This paper presents the design and implementation of a DSP-based controller for a super high-speed (>80,000 rpm permanent magnet synchronous motor (PMSM. The PMSM is a key component of the centrifugal compressor drive of a reverse Brayton cryocooler that is currently under development for NASA and Florida Solar Energy Center. The design of the PMSM open-loop control is presented. Experimental results with open-loop control schemes are presented. System optimization and analysis are also illustrated. They verify the effectiveness of the controller design and the optimization scheme.

  3. Coordinated analysis of sprites with high speed images and remote electromagnetic fields

    Science.gov (United States)

    Li, Jingbo

    One of the most dramatic discoveries in solar-terrestrial physics in the past two decades is the sprite, a high altitude optical glow produced by a lightning discharge. In this work, we infer the lightning-driven ambient electric fields by combining remote measured electromagnetic fields with numerical simulations. To accomplish this, we first extract the lightning source current from remotely measured magnetic fields with a deconvolution technique. Then we apply this current source to an existing 2-D Finite Difference Time Domain (FDTD) model to compute the electric fields at sprite altitudes. These inferred electric fields make up for the deficiency of lacking in-situ measurements. A data set collected at two observation sites in 2005 combines simultaneous measurements of sprite optical emissions and sprite-producing lightning radiated electromagnetic fields. Sprite images from a high speed camera and the measured wideband magnetic fields removed the limitations imposed by the small sprite temporal scale and allow us to precisely determine the sprite initiation time and the time delay from its parent lightning discharge. For 83 sprites analyzed, close to 50% of them are delayed for more than 10 ms after the lightning discharges and empirically defined as long-delayed sprites. Compared with short-delayed sprites, which are driven by the lightning return stroke, all these long-delayed sprites are associated with intense continuing current and large total charge moment changes. Besides that, sferic bursts and slow intensifications are frequently detected before those long-delayed sprites. These observations suggest a different initiation mechanism of long-delayed sprites. To reveal that, we inferred the lightning-driven electric fields at the sprite initiation time and altitude. Our results show that although long-delayed sprites are mainly driven by the continuing current instead of the lightning return stroke, the electric fields required to produce those long

  4. 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.

  5. 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.

  6. Edge-filter technique and dominant frequency analysis for high-speed railway monitoring with fiber Bragg gratings

    Science.gov (United States)

    Kouroussis, Georges; Kinet, Damien; Mendoza, Edgar; Dupuy, Julien; Moeyaert, Véronique; Caucheteur, Christophe

    2016-07-01

    Structural health and operation monitoring are of growing interest in the development of railway networks. Conventional systems of infrastructure monitoring already exist (e.g. axle counters, track circuits) but present some drawbacks. Alternative solutions are therefore studied and developed. In this field, optical fiber sensors, and more particularly fiber Bragg grating (FBG) sensors, are particularly relevant due to their immunity to electromagnetic fields and simple wavelength-division-multiplexing capability. Field trials conducted up to now have demonstrated that FBG sensors provide useful information about train composition, positioning, speed, acceleration and weigh-in-motion estimations. Nevertheless, for practical deployment, cost-effectiveness should be ensured, specifically at the interrogator side that has also to be fast (>1 kHz repetition rate), accurate (∼1 pm wavelength shift) and reliable. To reach this objective, we propose in this paper to associate a low cost and high-speed interrogator coupled with an adequate signal-processing algorithm to dynamically monitor cascaded wavelength-multiplexed FBGs and to accurately capture the parameters of interest for railway traffic monitoring. This method has been field-tested with a Redondo Optics Inc. interrogator based on the well-known edge-filter demodulation technique. To determine the train speed from the raw data, a dominant frequency analysis has been implemented. Using this original method, we show that we can retrieve the speed of the trains, even when the time history strain signature is strongly affected by the measurement noise. The results are assessed by complimentary data obtained from a spectrometer-based FBG interrogator.

  7. 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.

  8. A High-Speed Vision-Based Sensor for Dynamic Vibration Analysis Using Fast Motion Extraction Algorithms.

    Science.gov (United States)

    Zhang, Dashan; Guo, Jie; Lei, Xiujun; Zhu, Changan

    2016-04-22

    The development of image sensor and optics enables the application of vision-based techniques to the non-contact dynamic vibration analysis of large-scale structures. As an emerging technology, a vision-based approach allows for remote measuring and does not bring any additional mass to the measuring object compared with traditional contact measurements. In this study, a high-speed vision-based sensor system is developed to extract structure vibration signals in real time. A fast motion extraction algorithm is required for this system because the maximum sampling frequency of the charge-coupled device (CCD) sensor can reach up to 1000 Hz. Two efficient subpixel level motion extraction algorithms, namely the modified Taylor approximation refinement algorithm and the localization refinement algorithm, are integrated into the proposed vision sensor. Quantitative analysis shows that both of the two modified algorithms are at least five times faster than conventional upsampled cross-correlation approaches and achieve satisfactory error performance. The practicability of the developed sensor is evaluated by an experiment in a laboratory environment and a field test. Experimental results indicate that the developed high-speed vision-based sensor system can extract accurate dynamic structure vibration signals by tracking either artificial targets or natural features.

  9. Hardware performance of a scanning system for high speed analysis of nuclear emulsions

    CERN Document Server

    Arrabito, L; Bozza, C; Buontempo, S; Consiglio, L; Coppola, D; Cozzi, M; Damet, J; D'Ambrosio, N; De Lellis, G; De Serio, M; Capua, F D; Ferdinando, D D; Marco, N D; Esposito, L S; Giacomelli, G; Grella, G; Hauger, M; Juget, F; Kreslo, I; Giorgini, M; Ieva, M; Laktineh, I; Manai, K; Mandrioli, G; Marotta, A; Manzoor, S; Migliozzi, P; Monacelli, P; Muciaccia, M T; Pastore, A; Patrizii, L; Pistillo, C; Pozzato, M; Royole-Degieux, P; Romano, G; Rosa, G; Savvinov, N; Schembri, A; Lavina, L S; Simone, S; Sioli, M; Sirignano, C; Sirri, G; Sorrentino, G; Strolin, P; Tioukov, V; Waelchli, T

    2006-01-01

    The use of nuclear emulsions in very large physics experiments is now possible thanks to the recent improvements in the industrial production of emulsions and to the development of fast automated microscopes. In this paper the hardware performances of the European Scanning System (ESS) are described. The ESS is a very fast automatic system developed for the mass scanning of the emulsions of the OPERA experiment, which requires microscopes with scanning speeds of about 20 cm^2/h in an emulsion volume of 44 micron thickness.

  10. 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.

  11. Raptor Codes Performance Analysis on WI MAX Technology with high speed FFT/IFFT

    Directory of Open Access Journals (Sweden)

    Amit Kumar

    2012-04-01

    Full Text Available There are currently a large variety of wireless accessnetworks, including the emerging vehicular ad hocnetworks (VANETs. A large variety of applicationsutilizing these networks will demand features such as realtime,high-availability, and even instantaneous highbandwidthin some cases. Therefore, it is imperative fornetwork service providers to make the best possible use ofthe combined resources of available heterogeneousnetworks (wireless area networks (WLANs, UniversalMobile Telecommunications Systems, VANETs,Worldwide Interoperability for Microwave Access (WIMAX,etc. for connection support. When connectionsneed to migrate between heterogeneous networks forperformance and high-availability reasons, seamlessvertical handoff (VHO is a necessary first step. In the nearfuture, vehicular and other mobile applications will beexpected to have seamless VHO between heterogeneousaccess networks. Time-hopping ultra wideband (TH-UWBand direct-sequence ultra wideband (DS-UWB systems areamong the standards proposed for UWB communicationsscenarios. A general unified mathematical approach hasbeen proposed for calculating the bit error rate (BER forboth TH-UWB and DS-UWB systems in the presence ofmultiple-user interference and strong narrow-bandinterference in a multi-path scenario. Unlike many othermathematical models that provide upper or lower boundsfor BER, this model calculates the exact values for BER ingiven scenarios. A partial rake receiver has been chosen asthe receiving terminal. The modified Salem-Valenzuelachannel model has been used in this analysis. The modelcan assess the effect of any given narrow-band interferingsystems.

  12. 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

  13. Nonlinear Elastodynamic Behaviour Analysis of High-Speed Spatial Parallel Coordinate Measuring Machines

    Directory of Open Access Journals (Sweden)

    Xiulong Chen

    2012-10-01

    Full Text Available In order to study the elastodynamic behaviour of 4‐ universal joints‐ prismatic pairs‐ spherical joints / universal joints‐ prismatic pairs‐ universal joints 4‐UPS‐UPU high‐speed spatial PCMMs(parallel coordinate measuring machines, the nonlinear time‐varying dynamics model, which comprehensively considers geometric nonlinearity and the rigid‐flexible coupling effect, is derived by using Lagrange equations and finite element methods. Based on the Newmark method, the kinematics output response of 4‐UPS‐UPU PCMMs is illustrated through numerical simulation. The results of the simulation show that the flexibility of the links is demonstrated to have a significant impact on the system dynamics response. This research can provide the important theoretical base of the optimization design and vibration control for 4‐UPS‐UPU PCMMs.

  14. 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%.

  15. Computer program for analysis of high speed, single row, angular contact, spherical roller bearing, SASHBEAN. Volume 1: User's guide

    Science.gov (United States)

    Aggarwal, Arun K.

    1993-09-01

    The computer program SASHBEAN (Sikorsky Aircraft Spherical Roller High Speed Bearing Analysis) analyzes and predicts the operating characteristics of a Single Row, Angular Contact, Spherical Roller Bearing (SRACSRB). The program runs on an IBM or IBM compatible personal computer, and for a given set of input data analyzes the bearing design for it's ring deflections (axial and radial), roller deflections, contact areas and stresses, induced axial thrust, rolling element and cage rotation speeds, lubrication parameters, fatigue lives, and amount of heat generated in the bearing. The dynamic loading of rollers due to centrifugal forces and gyroscopic moments, which becomes quite significant at high speeds, is fully considered in this analysis. For a known application and it's parameters, the program is also capable of performing steady-state and time-transient thermal analyses of the bearing system. The steady-state analysis capability allows the user to estimate the expected steady-state temperature map in and around the bearing under normal operating conditions. On the other hand, the transient analysis feature provides the user a means to simulate the 'lost lubricant' condition and predict a time-temperature history of various critical points in the system. The bearing's 'time-to-failure' estimate may also be made from this (transient) analysis by considering the bearing as failed when a certain temperature limit is reached in the bearing components. The program is fully interactive and allows the user to get started and access most of its features with a minimal of training. For the most part, the program is menu driven, and adequate help messages were provided to guide a new user through various menu options and data input screens. All input data, both for mechanical and thermal analyses, are read through graphical input screens, thereby eliminating any need of a separate text editor/word processor to edit/create data files. Provision is also available to select

  16. Laser-high-speed-DSC: Process-oriented Thermal Analysis of PA 12 in Selective Laser Sintering

    Science.gov (United States)

    Lanzl, Lydia; Wudy, Katrin; Drexler, Maximilian; Drummer, Dietmar

    In the Selective Laser Sintering process very high heating rates occur due to the melting of the material by a laser. Extreme scanning rates could not be measured by conventional thermal analysis methods, since typical heating rates for DSC (differential scanning calorimetry) are between 5-20K min-1. By using a Laser-High-Speed-DSC, a self-developed combination of a Flash-DSC and a fitted laser head, the sample is directly heated by a CO2 laser like in the SLS process. These experiments allow a process-oriented thermal analyzation of the material. In this paper, the set-up and function of this new measuring method is introduced. Furthermore, the reliability of the measurements is evaluated by statistical design of experiment methods. By using this new measuring method, the time-dependent melting behavior of the polymer can be analyzed. Moreover, sample temperatures and heating rates dependent on laser exposure times can be quantified.

  17. High-speed, sparse-sampling three-dimensional photoacoustic computed tomography in vivo based on principal component analysis

    Science.gov (United States)

    Meng, Jing; Jiang, Zibo; Wang, Lihong V.; Park, Jongin; Kim, Chulhong; Sun, Mingjian; Zhang, Yuanke; Song, Liang

    2016-07-01

    Photoacoustic computed tomography (PACT) has emerged as a unique and promising technology for multiscale biomedical imaging. To fully realize its potential for various preclinical and clinical applications, development of systems with high imaging speed, reasonable cost, and manageable data flow are needed. Sparse-sampling PACT with advanced reconstruction algorithms, such as compressed-sensing reconstruction, has shown potential as a solution to this challenge. However, most such algorithms require iterative reconstruction and thus intense computation, which may lead to excessively long image reconstruction times. Here, we developed a principal component analysis (PCA)-based PACT (PCA-PACT) that can rapidly reconstruct high-quality, three-dimensional (3-D) PACT images with sparsely sampled data without requiring an iterative process. In vivo images of the vasculature of a human hand were obtained, thus validating the PCA-PACT method. The results showed that, compared with the back-projection (BP) method, PCA-PACT required ˜50% fewer measurements and ˜40% less time for image reconstruction, and the imaging quality was almost the same as that for BP with full sampling. In addition, compared with compressed sensing-based PACT, PCA-PACT had approximately sevenfold faster imaging speed with higher imaging accuracy. This work suggests a promising approach for low-cost, 3-D, rapid PACT for various biomedical applications.

  18. Online Condition Monitoring of a Rail Fastening System on High-Speed Railways Based on Wavelet Packet Analysis.

    Science.gov (United States)

    Wei, Jiahong; Liu, Chong; Ren, Tongqun; Liu, Haixia; Zhou, Wenjing

    2017-02-08

    The rail fastening system is an important part of a high-speed railway track. It is always critical to the operational safety and comfort of railway vehicles. Therefore, the condition detection of the rail fastening system, looseness or absence, is an important task in railway maintenance. However, the vision-based method cannot identify the severity of rail fastener looseness. In this paper, the condition of rail fastening system is monitored based on an automatic and remote-sensing measurement system. Meanwhile, wavelet packet analysis is used to analyze the acceleration signals, based on which two damage indices are developed to locate the damage position and evaluate the severity of rail fasteners looseness, respectively. To verify the effectiveness of the proposed method, an experiment is performed on a high-speed railway experimental platform. The experimental results show that the proposed method is effective to assess the condition of the rail fastening system. The monitoring system significantly reduces the inspection time and increases the efficiency of maintenance management.

  19. Online Condition Monitoring of a Rail Fastening System on High-Speed Railways Based on Wavelet Packet Analysis

    Directory of Open Access Journals (Sweden)

    Jiahong Wei

    2017-02-01

    Full Text Available The rail fastening system is an important part of a high-speed railway track. It is always critical to the operational safety and comfort of railway vehicles. Therefore, the condition detection of the rail fastening system, looseness or absence, is an important task in railway maintenance. However, the vision-based method cannot identify the severity of rail fastener looseness. In this paper, the condition of rail fastening system is monitored based on an automatic and remote-sensing measurement system. Meanwhile, wavelet packet analysis is used to analyze the acceleration signals, based on which two damage indices are developed to locate the damage position and evaluate the severity of rail fasteners looseness, respectively. To verify the effectiveness of the proposed method, an experiment is performed on a high-speed railway experimental platform. The experimental results show that the proposed method is effective to assess the condition of the rail fastening system. The monitoring system significantly reduces the inspection time and increases the efficiency of maintenance management.

  20. 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

  1. Time response analysis in suspension system design of a high-speed car

    Science.gov (United States)

    Pagwiwoko, Cosmas Pandit

    2010-03-01

    A land speed record vehicle is designed to run on a flat surface like salt lake where the wheels are normally made from solid metal with a special suspension system. The suspension is designed to provide a stable platform to keep the wheel treads on tract, to insulate the car and the driver from the surface irregularities and to take part of good handling properties. The surface condition of the lake beds is basically flat without undulations but with inconsistent surface textures and ridges. Spring with nonlinear rate is used with the reason that the resistance builds up roughly proportional to the aerodynamic download for keeping the height more nearly constant. The objective of the work is to produce an efficient method for assisting the design of suspension system. At the initial step, the stiffness and the damping constants are determined based on RMS optimization by following the optimization strategy i.e. to minimize the absolute acceleration respect to the relative displacement of the suspension. Power bond graph technique is then used to model the nonlinearity of the components i.e. spring and dashpot of the suspension system. This technique also enables to incorporate the interactions of dynamic response of the vehicle's body with aerodynamic flow as a result of the base excitation of the ground to the wheels. The simulation is conducted on the platform of Simulink-MATLAB and the interactions amongst the components within the system are observed in time domain to evaluate the effectiveness of the suspension.

  2. Full-field modal analysis during base motion excitation using high-speed 3D digital image correlation

    Science.gov (United States)

    Molina-Viedma, Ángel J.; López-Alba, Elías; Felipe-Sesé, Luis; Díaz, Francisco A.

    2017-10-01

    In recent years, many efforts have been made to exploit full-field measurement optical techniques for modal identification. Three-dimensional digital image correlation using high-speed cameras has been extensively employed for this purpose. Modal identification algorithms are applied to process the frequency response functions (FRF), which relate the displacement response of the structure to the excitation force. However, one of the most common tests for modal analysis involves the base motion excitation of a structural element instead of force excitation. In this case, the relationship between response and excitation is typically based on displacements, which are known as transmissibility functions. In this study, a methodology for experimental modal analysis using high-speed 3D digital image correlation and base motion excitation tests is proposed. In particular, a cantilever beam was excited from its base with a random signal, using a clamped edge join. Full-field transmissibility functions were obtained through the beam and converted into FRF for proper identification, considering a single degree-of-freedom theoretical conversion. Subsequently, modal identification was performed using a circle-fit approach. The proposed methodology facilitates the management of the typically large amounts of data points involved in the DIC measurement during modal identification. Moreover, it was possible to determine the natural frequencies, damping ratios and full-field mode shapes without requiring any additional tests. Finally, the results were experimentally validated by comparing them with those obtained by employing traditional accelerometers, analytical models and finite element method analyses. The comparison was performed by using the quantitative indicator modal assurance criterion. The results showed a high level of correspondence, consolidating the proposed experimental methodology.

  3. A spatio-temporal Gaussian-Conical wavelet with high aperture selectivity for motion and speed analysis

    CERN Document Server

    Brault, Patrice

    2012-01-01

    The construction of a spatio-temporal wavelet and its tuning to speed was first realized in the 90s on the Morlet wavelet by M. Duval-Destin \\cite{Duval-Destin91a,Duval-Destin92}. This enabled to demonstrate the capacities of the speed-tuned Morlet for psychovisual analysis. This construction was also used very efficiently in a powerful aerial target tracking algorithm by Mujica et al.\\cite{Mujica99,Mujica2000}. In the last decade, this tool was proposed as an elegant and efficient alternative framework to the Optical Flow (OF), the Block Matching (BM) or the phase difference, for the study of motion estimation in image sequences. Nevertheless, the aperture selectivity of the 2D+T Morlet wavelet presents some difficulties. Here we propose to replace the 2D Morlet wavelet by a Gaussian-Conical (GC) wavelet for the spatial part of the spatio-temporal wavelet, since the GC wavelet has a better aperture selectivity and allows a very simple adjustment of the aperture. Therefore we build a new, highly directional, ...

  4. Analysis of the high-speed polysilicon photodetector in fully standard CMOS technology

    NARCIS (Netherlands)

    Radovanović, S.; Annema, A.J.; Nauta, B.

    2003-01-01

    A high-performance lateral polysilicon photodiode was designed in standard 0.18 um CMOS technology. The device has a frequency bandwidth far in the GHz range: the measured bandwidth of the poly photodiode was 6 GHz, which gure was limited by the measurement equipment. The high intrinsic (physical) b

  5. Terminal Performance of Lead-Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

    CERN Document Server

    Courtney, Elijah; Andrusiv, Lubov; Courtney, Michael

    2016-01-01

    Due to concerns about environmental and industrial hazards of lead, a number of military, law enforcement, and wildlife management agencies are giving careful consideration to lead-free ammunition. The goal of lead-free bullets is to gain the advantages of reduced lead use in the environment while maintaining equal or better terminal performance. Accepting reduced terminal performance would foolishly risk the lives of military and law enforcement personnel. This paper uses the established technique of studying bullet impacts in ballistic gelatin to characterize the terminal performance of eight commercial off-the- shelf lead-free handgun bullets for comparison with earlier analysis of jacketed lead bullets. Peak retarding force and energy deposit in calibrated ballistic gelatin are quantified using high speed video. The temporary stretch cavities and permanent wound cavities are also characterized. Two factors tend to reduce the terminal performance of these lead-free projectiles compared to similar jacketed ...

  6. Semi-continuous high speed gas analysis of generated vapors of chemical warfare agents

    NARCIS (Netherlands)

    Trap, H.C.; Langenberg, J.P.

    1999-01-01

    A method is presented for the continuous analysis of generated vapors of the nerve agents soman and satin and the blistering agent sulfur mustard. By using a gas sampling valve and a very short (15 cm) column connected to an on-column injector with a 'standard length' column, the system can either

  7. Analysis of Mechanical Seals for High-Speed Centrifugal Gas Compressors

    Directory of Open Access Journals (Sweden)

    K.N. Nwaigwe

    2012-08-01

    Full Text Available A study aimed at seal selection efficiency for centrifugal pumps in the oil and gas industry is presented. A detailed analysis of mechanical seals in use in exploration and production activities of the oil and gas sector was undertaken. The approach of analysis was using seal design equations as mathematical models for simulating the performance of the mechanical seal. The results showed a mechanical seal with balance value of 0.5, an increased surface area between mating surfaces; provided with a flush system to enhance cooling and with seal face gap of 50 mm or less between the mating surfaces for minimal or zero leakage. The obtained results can aid the industries in seal selection and seal manufacturers in seal specifications.

  8. Analysis of the Impacts of Distribution-Connected PV Using High-Speed Data Sets: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bank, J.; Mather, B.

    2013-03-01

    This paper, presented at the IEEE Green Technologies Conference 2013, utilizes information from high resolution data acquisition systems developed at the National Renewable Energy Laboratory and deployed on a high-penetration PV distribution system to analyze the variability of different electrical parameters. High-resolution solar irradiance data is also available in the same area which is used to characterize the available resource and how it affects the electrical characteristics of the study circuit. This paper takes a data-driven look at the variability caused by load and compares those results against times when significant PV production is present. Comparisons between the variability in system load and the variability of distributed PV generation are made.

  9. Dynamic analysis of high speed gears by using loaded static transmission error

    Science.gov (United States)

    Özgüven, H. Nevzat; Houser, D. R.

    1988-08-01

    A single degree of freedom non-linear model is used for the dynamic analysis of a gear pair. Two methods are suggested and a computer program is developed for calculating the dynamic mesh and tooth forces, dynamic factors based on stresses, and dynamic transmission error from measured or calculated loaded static transmission errors. The analysis includes the effects of variable mesh stiffness and mesh damping, gear errors (pitch, profile and runout errors), profile modifications and backlash. The accuracy of the method, which includes the time variation of both mesh stiffness and damping is demonstrated with numerical examples. In the second method, which is an approximate one, the time average of the mesh stiffness is used. However, the formulation used in the approximate analysis allows for the inclusion of the excitation effect of the variable mesh stiffness. It is concluded from the comparison of the results of the two methods that the displacement excitation resulting from a variable mesh stiffness is more important than the change in system natural frequency resulting from the mesh stiffness variation. Although the theory presented is general and applicable to spur, helical and spiral bevel gears, the computer program prepared is for only spur gears.

  10. 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

  11. A High-Speed All-Digital Technique for Agricultural Spray Measurement and Flow Visualization Image Analysis in Pesticide Application

    Directory of Open Access Journals (Sweden)

    Deyun Wei

    2013-01-01

    Full Text Available In order to solve the faults in usual measurements of droplet distribution and motion in agricultural spraying field, a new method is given for the analysis of droplets characteristics and motion with PDIA (Particle/ Droplet Image Analysis and digital image processing technique. During the analysis of the size of droplet and the velocity, images of droplets in spray field have been captured by using high-speed imager. The parameter of droplet such as size, perimeter, equivalent diameter, shape factor and position etc., have been calculated with digital image processing technology. The trace of droplet in different frames has been tracked with the method, which is based on flag tracking and droplet neighborhood matching probability technique. The results showed this method can both realize the motion trace of droplet in different image frames and analyses the velocity of droplet. This technique can detect the droplet parameters quickly and accurately for agricultural sprays and provide the basic way for research on flow visualization image analysis in pesticide application.

  12. Bullet Retarding Forces in Ballistic Gelatin by Analysis of High Speed Video

    Science.gov (United States)

    2012-12-28

    ADA291697&Location=U2&doc=GetTRDoc.pdf . Accessed July 15, 2012. Bruchey WJ Jr., Sturdivan LM. An Instrumented Range Meeting the Requirements of a Wound...318. Selman YS, et al., Medico -legal Study of Shockwave Damage by High Velocity Missiles in Firearm Injuries, Fac Med Baghdad 2011; Vol. 53

  13. 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....

  14. High-speed ion-pair partition chromatography in pharmaceutical analysis.

    Science.gov (United States)

    Santi, W; Huen, J M; Frei, R W

    1975-12-24

    Ion-pair chromatography offers attractive possibilities in pharmaceutical analysis. The specificity of the separation systems can be varied over a wide range by appropriate selection of the stationary phase. The choice of a suitable counter-ion can also drastically improve the detection limit, permitting the determination of drug substances in low dosage and possibly of by-products or breakdown products. Ion-pair chromatography of tropane and ergot alkaloids has been investigated using picrate as counter-ion. Alumina, Kieselguhr and various grades of silica gel have been tested as supports. Partition properties studied in a batch procedure have been compared with the actual chromatographic conditions. Columns (10 cm) filled with silical gel (particle size, 5 mum; pore size, 1000 A) show the best performance in the separation of hyoscyamine, scopolamine and ergotamine as picrate ion-pairs. Close control of pH and temperature is essential for reproducible separations. Improvements in detection limits between 100 and 300 times have been observed with these systems. Ion-pair extractions of these alkaloids from dosage forms can be used for sample preparation prior to injection on the the column. This provides an added degree of selectivity and sensitivity.

  15. High speed analysis of used hydrocarbons, particularly waste oils; Schnellanalyse von gebrauchten Kohlenwasserstoffen, insbesondere Altoelen

    Energy Technology Data Exchange (ETDEWEB)

    Yacoub-George, E.; Endres, H.E. [Fraunhofer Institut fuer Zuverlaessigkeit und Mikrointegration (IZM), Muenchen (Germany)

    2002-12-01

    According to a decision of the European Court of Justice material recycling of waste oil must take priority over thermal recycling. The present study investigates the possibilities to classify waste oil samples according to their potential for material recycling on-site at the waste oil producer. The first part of the study surveys the state of the art in chemical analysis of waste oil and in oil quality monitoring with sensing elements in vehicles. It was shown, that the chemical analysis of waste oil is dominated by methods for monitoring the oil quality and by methods for the determination of harmful substances. For sensor-based oil condition monitoring in vehicles different approaches were discussed in literature. Most sensor systems work in a capacitive mode and use the change of the electrical properties of the oil for analysing oil quality. The second part of the study investigates, whether waste oil can be classified according to its potential for material recycling by the following physical parameters: viscosity, density, viscoelastic properties, conductivity and relative permittivity. This was done by performing and evaluating measurements at 26 different waste oil samples with a combi-SAW-/IDK-dipstick sensor. The results showed, that the SAW- und IDK-signals contain only little information permitting to classify waste oil samples according to their potential for material recycling. A classification of waste oil samples with the combi-SAW-/IDK-dipstick sensor was impossible, even when the signal evaluation was done by using modern methods of chemometrics, as e. g. the multivariate statistics. A further series of measurements showed, that since the conductivity of the waste oil samples is too low, cyclovoltammetry is also an unsuitable method to classify waste oil samples on-site. On the other hand, the study showed that the investigated waste oil samples can be classified by IR-spectroscopy in combination with multivariate statistics. By evaluating the

  16. A CFD analysis of blade row interactions within a high-speed axial compressor

    Science.gov (United States)

    Richman, Michael Scott

    Aircraft engine design provides many technical and financial hurdles. In an effort to streamline the design process, save money, and improve reliability and performance, many manufacturers are relying on computational fluid dynamic simulations. An overarching goal of the design process for military aircraft engines is to reduce size and weight while maintaining (or improving) reliability. Designers often turn to the compression system to accomplish this goal. As pressure ratios increase and the number of compression stages decrease, many problems arise, for example stability and high cycle fatigue (HCF) become significant as individual stage loading is increased. CFD simulations have recently been employed to assist in the understanding of the aeroelastic problems. For accurate multistage blade row HCF prediction, it is imperative that advanced three-dimensional blade row unsteady aerodynamic interaction codes be validated with appropriate benchmark data. This research addresses this required validation process for TURBO, an advanced three-dimensional multi-blade row turbomachinery CFD code. The solution/prediction accuracy is characterized, identifying key flow field parameters driving the inlet guide vane (IGV) and stator response to the rotor generated forcing functions. The result is a quantified evaluation of the ability of TURBO to predict not only the fundamental flow field characteristics but the three dimensional blade loading.

  17. High-speed extended-term time-domain simulation for online cascading analysis of power system

    Science.gov (United States)

    Fu, Chuan

    A high-speed extended-term (HSET) time domain simulator (TDS), intended to become a part of an energy management system (EMS), has been newly developed for use in online extended-term dynamic cascading analysis of power systems. HSET-TDS includes the following attributes for providing situational awareness of high-consequence events: (i) online analysis, including n-1 and n-k events, (ii) ability to simulate both fast and slow dynamics for 1-3 hours in advance, (iii) inclusion of rigorous protection-system modeling, (iv) intelligence for corrective action ID, storage, and fast retrieval, and (v) high-speed execution. Very fast on-line computational capability is the most desired attribute of this simulator. Based on the process of solving algebraic differential equations describing the dynamics of power system, HSET-TDS seeks to develop computational efficiency at each of the following hierarchical levels, (i) hardware, (ii) strategies, (iii) integration methods, (iv) nonlinear solvers, and (v) linear solver libraries. This thesis first describes the Hammer-Hollingsworth 4 (HH4) implicit integration method. Like the trapezoidal rule, HH4 is symmetrically A-Stable but it possesses greater high-order precision (h4 ) than the trapezoidal rule. Such precision enables larger integration steps and therefore improves simulation efficiency for variable step size implementations. This thesis provides the underlying theory on which we advocate use of HH4 over other numerical integration methods for power system time-domain simulation. Second, motivated by the need to perform high speed extended-term time domain simulation (HSET-TDS) for on-line purposes, this thesis presents principles for designing numerical solvers of differential algebraic systems associated with power system time-domain simulation, including DAE construction strategies (Direct Solution Method), integration methods(HH4), nonlinear solvers(Very Dishonest Newton), and linear solvers(SuperLU). We have

  18. 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.

  19. 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.

  20. Vertical Random Vibration Analysis of Track-Subgrade Coupled System in High Speed Railway with Pseudoexcitation Method

    Directory of Open Access Journals (Sweden)

    Xinwen Yang

    2016-01-01

    Full Text Available In order to reduce the ground-borne vibration caused by wheel/rail interaction in the ballastless track of high speed railways, viscoelastic asphalt concrete materials are filled between the track and the subgrade to attenuate wheel/rail force. A high speed train-track-subgrade vertical coupled dynamic model is developed in the frequency domain. In this model, coupling effects between the vehicle and the track and between the track and the subgrade are considered. The full vehicle is represented by some rigid body models of one body, two bogies, and four wheelsets connected to each other with springs and dampers. The track and subgrade system is considered as a multilayer beam model in which layers are connected to each other with springs and damping elements. The vertical receptance of the rail is discussed and the receptance contribution of the wheel/rail interaction is investigated. Combined with the pseudoexcitation method, a solution of the random dynamic response is presented. The random vibration responses and transfer characteristics of the ballastless track and subgrade system are obtained under track random irregularity when a high speed vehicle runs through. The influences of asphalt concrete layer’s stiffness and vehicle speed on track and subgrade coupling vibration are analyzed.

  1. Results and Analysis of a L2F Flow Field Investigation within a High-Speed High-Pressure Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    The paper describes experimental results obtained using a laser two-focus anemometry technique in a high-speed,high-pressure ratio unshrouded centrifugal compressor.Measurements in such a small impeller are extremely difficult as the flow is restricted to marrow passages and as the temperature rise is very high.Even if the working principle of laser anemometry is well documented in literature,some specialities of our LA system are discussed.A description and an analysis of the inlet flow field.based on integral methods,are propsed.Some passage velocity contours are presented.Whereas a potential flow structure exists up to the high meridional curvature region,the throughflow patterm is largely distorted in the radial part of the impeller.Noticeable differences in flow pattern between both channels are found,particularyly through the low momentum fluid zone.A qualitative study of the vortical mechanisms ascribes them to the tip clearance effects.

  2. An Impact Velocity Device Design for Blood Spatter Pattern Generation with Considerations for High-Speed Video Analysis.

    Science.gov (United States)

    Stotesbury, Theresa; Illes, Mike; Vreugdenhil, Andrew J

    2016-03-01

    A mechanical device that uses gravitational and spring compression forces to create spatter patterns of known impact velocities is presented and discussed. The custom-made device uses either two or four springs (k1 = 267.8 N/m, k2 = 535.5 N/m) in parallel to create seventeen reproducible impact velocities between 2.1 and 4.0 m/s. The impactor is held at several known spring extensions using an electromagnet. Trigger inputs to the high-speed video camera allow the user to control the magnet's release while capturing video footage simultaneously. A polycarbonate base is used to allow for simultaneous monitoring of the side and bottom views of the impact event. Twenty-four patterns were created across the impact velocity range and analyzed using HemoSpat. Area of origin estimations fell within an acceptable range (ΔXav = -5.5 ± 1.9 cm, ΔYav = -2.6 ± 2.8 cm, ΔZav = +5.5 ± 3.8 cm), supporting distribution analysis for the use in research or bloodstain pattern training. This work provides a framework for those interested in developing a robust impact device.

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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

  9. Distributed Large Data-Object Environments: End-to-End Performance Analysis of High Speed Distributed Storage Systems in Wide Area ATM Networks

    Science.gov (United States)

    Johnston, William; Tierney, Brian; Lee, Jason; Hoo, Gary; Thompson, Mary

    1996-01-01

    We have developed and deployed a distributed-parallel storage system (DPSS) in several high speed asynchronous transfer mode (ATM) wide area networks (WAN) testbeds to support several different types of data-intensive applications. Architecturally, the DPSS is a network striped disk array, but is fairly unique in that its implementation allows applications complete freedom to determine optimal data layout, replication and/or coding redundancy strategy, security policy, and dynamic reconfiguration. In conjunction with the DPSS, we have developed a 'top-to-bottom, end-to-end' performance monitoring and analysis methodology that has allowed us to characterize all aspects of the DPSS operating in high speed ATM networks. In particular, we have run a variety of performance monitoring experiments involving the DPSS in the MAGIC testbed, which is a large scale, high speed, ATM network and we describe our experience using the monitoring methodology to identify and correct problems that limit the performance of high speed distributed applications. Finally, the DPSS is part of an overall architecture for using high speed, WAN's for enabling the routine, location independent use of large data-objects. Since this is part of the motivation for a distributed storage system, we describe this architecture.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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)

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. 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.

  1. Large-scale analysis of high-speed atomic force microscopy data sets using adaptive image processing

    Directory of Open Access Journals (Sweden)

    Blake W. Erickson

    2012-11-01

    Full Text Available Modern high-speed atomic force microscopes generate significant quantities of data in a short amount of time. Each image in the sequence has to be processed quickly and accurately in order to obtain a true representation of the sample and its changes over time. This paper presents an automated, adaptive algorithm for the required processing of AFM images. The algorithm adaptively corrects for both common one-dimensional distortions as well as the most common two-dimensional distortions. This method uses an iterative thresholded processing algorithm for rapid and accurate separation of background and surface topography. This separation prevents artificial bias from topographic features and ensures the best possible coherence between the different images in a sequence. This method is equally applicable to all channels of AFM data, and can process images in seconds.

  2. 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 ...

  3. Análisis experimental del torneado de alta velocidad del acero AISI 1045 // Experimental analysis of high speed turning of AISI 1045 steel gears

    Directory of Open Access Journals (Sweden)

    Luís Wilfredo Hernández‐González

    2012-01-01

    Full Text Available El objetivo de este trabajo es el estudio experimental de la evolución del desgaste del flanco de dosinsertos de carburo recubiertos y un cermet, durante el torneado en seco del acero AISI 1045 con 500 y600 m/min de velocidad de corte. Los resultados fueron comparados utilizando el análisis de varianza y deregresión. La investigación mostró un efecto significativo de la velocidad de corte y del tiempo demaquinado en el desgaste del flanco. El mejor desempeño fue para el carburo recubierto con tres capas,mientras que a elevada velocidad de corte el carburo con dos capas sufrió el mayor desgaste, lo cual sedebe a que cuando pierde sus recubrimientos el substrato del inserto queda desprotegido y el desgastecrece rápidamente por la extremas condiciones del mecanizado por alta velocidad. Además, se planteanrecomendaciones del tiempo de maquinado de los insertos dadas las condiciones de elaboración por altavelocidad.Palabras claves: torneado de alta velocidad, desgaste del flanco, acero AISI 1045, estudio experimental.__________________________________________________________________________AbstractThis work deals with the experimental study of the flank wear evolution of two coating carbide inserts and acermet insert during the dry turning of AISI 1045 steel with 500 and 600 m/min cutting speed. The resultswere compared using the variance and regression analysis. The investigation showed a significant effectof cutting speed and machining time on the flank wear in high speed machining. The three coating layersinsert showed the best performance while the two layers insert had the worst behaviour of the cutting toolwear at high cutting speed, this is because once the coating film is peeled off, the substrate of the insertbecomes uncovered and the wear grows rapidly due to the extreme machining conditions for high speed.Besides, the machining time recommendations of inserts for the cutting conditions at high speed areexposed.Key words: high

  4. Coupling Analysis of Low-Speed Multiphase Flow and High-Frequency Electromagnetic Field in a Complex Pipeline Structure

    Directory of Open Access Journals (Sweden)

    Xiaokai Huo

    2014-01-01

    Full Text Available Accurate estimation of water content in an oil-water mixture is a key technology in oil exploration and production. Based on the principles of the microwave transmission line (MTL, the logging probe is an important water content measuring apparatus. However, the effects of mixed fluid flow on the measurement of electromagnetic field parameters are rarely considered. This study presents the coupling model for low-speed multiphase flow and high-frequency electromagnetic field in a complex pipeline structure. We derived the S-parameter equations for the stratified oil/water flow model. The corresponding relationship between the S-parameters and water holdup is established. Evident coupling effects of the fluid flow and the electromagnetic field are confirmed by comparing the calculated S-parameters for both stratified and homogeneous flow patterns. In addition, a multiple-solution problem is analyzed for the inversion of dielectric constant from the S-parameters. The most sensitive phase angle range is determined to improve the detection of variation in the dielectric constant. Suggestions are proposed based on the influence of the oil/water layer on measurement sensitivity to optimize the geometric parameters of a device structure. The method proposed elucidates how accuracy and sensitivity can be improved in water holdup measurements under high water content conditions.

  5. Data Rods: High Speed, Time-Series Analysis of Massive Cryospheric Data Sets Using Object-Oriented Database Methods

    Science.gov (United States)

    Liang, Y.; Gallaher, D. W.; Grant, G.; Lv, Q.

    2011-12-01

    Change over time, is the central driver of climate change detection. The goal is to diagnose the underlying causes, and make projections into the future. In an effort to optimize this process we have developed the Data Rod model, an object-oriented approach that provides the ability to query grid cell changes and their relationships to neighboring grid cells through time. The time series data is organized in time-centric structures called "data rods." A single data rod can be pictured as the multi-spectral data history at one grid cell: a vertical column of data through time. This resolves the long-standing problem of managing time-series data and opens new possibilities for temporal data analysis. This structure enables rapid time- centric analysis at any grid cell across multiple sensors and satellite platforms. Collections of data rods can be spatially and temporally filtered, statistically analyzed, and aggregated for use with pattern matching algorithms. Likewise, individual image pixels can be extracted to generate multi-spectral imagery at any spatial and temporal location. The Data Rods project has created a series of prototype databases to store and analyze massive datasets containing multi-modality remote sensing data. Using object-oriented technology, this method overcomes the operational limitations of traditional relational databases. To demonstrate the speed and efficiency of time-centric analysis using the Data Rods model, we have developed a sea ice detection algorithm. This application determines the concentration of sea ice in a small spatial region across a long temporal window. If performed using traditional analytical techniques, this task would typically require extensive data downloads and spatial filtering. Using Data Rods databases, the exact spatio-temporal data set is immediately available No extraneous data is downloaded, and all selected data querying occurs transparently on the server side. Moreover, fundamental statistical

  6. 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.

  7. 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

  8. Preparative isolation and analysis of alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root using ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography.

    Science.gov (United States)

    Chen, Miao; Liu, Liangliang; Chen, Xiaoqing

    2014-07-01

    A simple, rapid, and effective assay based on ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography was developed for screening and purifying alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root extract. Experiments were carried out to optimize binding conditions including alcohol dehydrogenase concentration, incubation time, temperature, and pH. By comparing the chromatograms, three compounds were found possessing alcohol dehydrogenase binding activity in Glycyrrhiza uralensis root. Under the target-guidance of ultrafiltration combined with the high-performance liquid chromatography experiment, liquiritin (1), isoliquiritin (2), and liquiritigenin (3) were separated by high-speed countercurrent chromatography using ethyl acetate/methanol/water (5:1:4) as the solvent system. The alcohol dehydrogenase inhibitory activities of these three isolated compounds were assessed; compound 2 showed strongest inhibitory activity with an IC50 of 8.95 μM. The results of the present study indicated that the combinative method using ultrafiltration, high-performance liquid chromatography and high-speed countercurrent chromatography could be widely applied for the rapid screening and isolation of enzyme inhibitors from complex mixtures.

  9. 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.

  10. 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.

  11. 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.

  12. 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,…

  13. 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.

  14. Computer program for analysis of high speed, single row, angular contact, spherical roller bearing, SASHBEAN. Volume 2: Mathematical formulation and analysis

    Science.gov (United States)

    Aggarwal, Arun K.

    1993-01-01

    Spherical roller bearings have typically been used in applications with speeds limited to about 5000 rpm and loads limited for operation at less than about 0.25 million DN. However, spherical roller bearings are now being designed for high load and high speed applications including aerospace applications. A computer program, SASHBEAN, was developed to provide an analytical tool to design, analyze, and predict the performance of high speed, single row, angular contact (including zero contact angle), spherical roller bearings. The material presented is the mathematical formulation and analytical methods used to develop computer program SASHBEAN. For a given set of operating conditions, the program calculates the bearings ring deflections (axial and radial), roller deflections, contact areas stresses, depth and magnitude of maximum shear stresses, axial thrust, rolling element and cage rotational speeds, lubrication parameters, fatigue lives, and rates of heat generation. Centrifugal forces and gyroscopic moments are fully considered. The program is also capable of performing steady-state and time-transient thermal analyses of the bearing system.

  15. 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.

  16. High-Speed Visual Analysis of Fluid Flow and Heat Transfer in Oscillating Heat Pipes with Different Diameters

    Directory of Open Access Journals (Sweden)

    Xiangdong Liu

    2016-10-01

    Full Text Available The oscillating heat pipe (OHP is a new member in the family of heat pipes, and it has great potential applications in energy conservation. However, the fluid flow and heat transfer in the OHP as well as the fundamental effects of inner diameter on them have not been fully understood, which are essential to the design and optimization of the OHP in real applications. Therefore, by combining the high-speed visualization method and infrared thermal imaging technique, the fluid flow and thermal performance in the OHPs with inner diameters of 1, 2 and 3 mm are presented and analyzed. The results indicate that three fluid flow motions, including small oscillation, bulk oscillation and circulation, coexist or, respectively, exist alone with the increasing heating load under different inner diameters, with three flow patterns occurring in the OHPs, viz. bubbly flow, slug flow and annular flow. These fluid flow motions are closely correlated with the heat and mass transfer performance in the OHPs, which can be reflected by the characteristics of infrared thermal images of condensers. The decrease in the inner diameter increases the frictional flow resistance and capillary instability while restricting the nucleate boiling in OHPs, which leads to a smaller proportion of bubbly flow, a larger proportion of short slug flow, a poorer thermal performance, and easier dry-out of working fluid. In addition, when compared with the 2 mm OHP, the increasing role of gravity induces the thermosyphon effect and weakens the ‘bubble pumping’ action, which results in a little smaller and bigger thermal resistances of 3 mm OHP under small and bulk oscillation of working fluid, respectively.

  17. 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

  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. 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.

  5. 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.

  6. 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.

  7. Design and Analysis of High Speed Pumps (Conception et analyse des pompes a grande vitesse) (CD-ROM)

    Science.gov (United States)

    for more compact and lighter pumps has led to an increased rotational speed up to the point where cavitation and rotordynamics become a major issue. The...better insight into the real flow in pump impellers. Rotordynamic problems and their impact on seals and bearings are discussed in detail, including the

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. a Comparative Earthwork and Cost Analysis of Improving AN Existing Railway Line and Constructing a New High-Speed Line in Turkey

    Science.gov (United States)

    Gumus, K. A.; Gulal, V. E.

    2016-10-01

    In the past few decades, high-speed railways have become an important transportation system due to their high operational speed, and globally, the networks of these railways have been extended. In addition, there is ongoing work on the construction of new high-speed railways as well as improving existing lines to achieve the same operational speed. To contribute to high-speed railway works in Turkey, this study compared two high-speed railway lines; an existing conventional line, the design of which was improved, and a new high-speed line. The design of an existing conventional railway line was improved according to optimal geometric characteristics of high-speed railways and an alternative line was simulated. These two lines were evaluated on three different types of land in terms of the required volume of earthworks, engineering structures and total cost. The results show that the length of the conventional line was reduced after the improvement process; however, new engineering structures are needed. Furthermore, compared to the alternative line, the track length and total length of engineering structures required for the improvement of the existing line was shorter and the volume of required earthworks was less resulting in lower costs.

  13. 快速锻造液压机动载因数分析%Dynamic load factor analysis for high-speed forging hydraulic press

    Institute of Scientific and Technical Information of China (English)

    高俊峰; 孙茂; 芦光荣; 刘崇民

    2012-01-01

    通过对20 MN下拉式快锻压机及对液压系统动载分析,介绍了快锻液压机组设计中动载因数的重要性;就如何降低液压冲击及振动提出了分析方法,尤其是分析了液压瞬变与流体在管道内的振动对机械系统振动的影响;提出了快锻液压机组设计中降低动载因数应遵守的准则.分析研究结果对液压系统设计中对泵、阀、管道等组件单元的选型与计算具有指导意义.%The importance of dynamic load factor in design of the high-speed hydraulic forging press was introduced through the dynamic load analysis for 20 MN pull-down type high-speed hydraulic forging press and its hydraulic system. The analytical method for how to reduce the hydraulic impact &- vibration was presented. The effect for the mechanical system vibration was especially analysed when the hydraulic transient and the fluid were vibrating in the piping. The criterion for the reducing dynamic load factor on the design of high-speed hydraulic forging press was provided. The analysis and research results have the guidance means for the model selection and calculation for pump, valve, piping and etc. in the hydraulic system designing.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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).

  19. Analysis of the kinematic characteristics of a high-speed parallel robot with Schönflies motion: Mobility, kinematics, and singularity

    Science.gov (United States)

    Xie, Fugui; Liu, Xin-Jun

    2016-06-01

    This study introduces a high-speed parallel robot with Schönflies motion. This robot exhibits a promising prospect in realizing high-speed pick-andplace manipulation for packaging production lines. The robot has four identical limbs and a single platform. Its compact structure and single-platform concept provides this robot with good dynamic response potential. A line graph method based on Grassmann line geometry is used to investigate the mobility characteristics of the proposed robot. A generalized Blanding rule is also introduced into this procedure to realize mutual conversion between the line graphs for motions and constraints. Subsequently, the inverse kinematics is derived, and the singularity issue of the robot is investigated using both qualitative and quantitative approaches. Input and output transmission singularity indices are defined based on the reciprocal product in screw theory and the virtual coefficient by considering motion/force transmission performance. Thereafter, the singular loci of the proposed robot with specific geometric parameters are derived. The mobility analysis, inverse kinematics modeling, and singularity analysis conducted in this study are helpful in developing the robot.

  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. HiSPoD: a program for high-speed polychromatic X-ray diffraction experiments and data analysis on polycrystalline samples.

    Science.gov (United States)

    Sun, Tao; Fezzaa, Kamel

    2016-07-01

    A high-speed X-ray diffraction technique was recently developed at the 32-ID-B beamline of the Advanced Photon Source for studying highly dynamic, yet non-repeatable and irreversible, materials processes. In experiments, the microstructure evolution in a single material event is probed by recording a series of diffraction patterns with extremely short exposure time and high frame rate. Owing to the limited flux in a short pulse and the polychromatic nature of the incident X-rays, analysis of the diffraction data is challenging. Here, HiSPoD, a stand-alone Matlab-based software for analyzing the polychromatic X-ray diffraction data from polycrystalline samples, is described. With HiSPoD, researchers are able to perform diffraction peak indexing, extraction of one-dimensional intensity profiles by integrating a two-dimensional diffraction pattern, and, more importantly, quantitative numerical simulations to obtain precise sample structure information.

  4. 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...

  5. 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.

  6. COMPUTER MODELING IN DEFORM-3D FOR ANALYSIS OF PLASTIC FLOW IN HIGH-SPEED HOT EXTRUSION OF BIMETALLIC FORMATIVE PARTS OF DIE TOOLING

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2015-01-01

    Full Text Available The modern development of industrial production is closely connected with the use of science-based and high technologies to ensure competitiveness of the manufactured products on the world market. There is also much tension around an energy- and resource saving problem which can be solved while introducing new technological processes and  creation of new materials that provide productivity increase through automation and improvement of tool life. Development and implementation of such technologies are rather often considered as time-consuming processes  which are connected with complex calculations and experimental investigations. Implementation of a simulation modelling for materials processing using modern software products serves an alternative to experimental and theoretical methods of research.The aim of this paper is to compare experimental results while obtaining bimetallic samples of a forming tool through the method of speed hot extrusion and the results obtained with the help of computer simulation using DEFORM-3D package and a finite element method. Comparative analysis of plastic flow of real and model samples has shown that the obtained models provide high-quality and reliable picture of plastic flow during high-speed hot extrusion. Modeling in DEFORM-3D make it possible to eliminate complex calculations and significantly reduce a number of experimental studies while developing new technological processes.

  7. Thermogravimetry speeds up proximate analysis of coal

    Energy Technology Data Exchange (ETDEWEB)

    Baur, P.

    1983-03-01

    Thermogravimetric analysis is not an ASTM standard method for proximate analysis of coal and coke, but it is widely used in US laboratories because of its speed, accuracy and flexibility. Equipment available from different manufacturers is compared and the experience of a number of users is recounted.

  8. 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...

  9. An all-statistics, high-speed algorithm for the analysis of copy number variation in genomes.

    Science.gov (United States)

    Chen, Chih-Hao; Lee, Hsing-Chung; Ling, Qingdong; Chen, Hsiao-Rong; Ko, Yi-An; Tsou, Tsong-Shan; Wang, Sun-Chong; Wu, Li-Ching; Lee, H C

    2011-07-01

    Detection of copy number variation (CNV) in DNA has recently become an important method for understanding the pathogenesis of cancer. While existing algorithms for extracting CNV from microarray data have worked reasonably well, the trend towards ever larger sample sizes and higher resolution microarrays has vastly increased the challenges they face. Here, we present Segmentation analysis of DNA (SAD), a clustering algorithm constructed with a strategy in which all operational decisions are based on simple and rigorous applications of statistical principles, measurement theory and precise mathematical relations. Compared with existing packages, SAD is simpler in formulation, more user friendly, much faster and less thirsty for memory, offers higher accuracy and supplies quantitative statistics for its predictions. Unique among such algorithms, SAD's running time scales linearly with array size; on a typical modern notebook, it completes high-quality CNV analyses for a 250 thousand-probe array in ∼1 s and a 1.8 million-probe array in ∼8 s.

  10. 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.

  11. Comparative histopathological analysis of human pulps after class I cavity preparation with a high-speed air-turbine handpiece or Er:YAG laser

    Science.gov (United States)

    Kina, J. F.; Benitez, P. C.; Lizarelli, R. F. Z.; Bagnato, V. S.; Martinez, T. C.; Oliveira, C. F.; Hebling, J.; Costa, C. A. S.

    2008-12-01

    The purpose of this study was to comparatively evaluate the response of human pulps after cavity preparation with different devices. Deep class I cavities were prepared in sound mandibular premolars using either a high-speed air-turbine handpiece (Group 1) or an Er:YAG laser (Group 2). Following total acid etching and the application of an adhesive system, all cavities were restored with composite resin. Fifteen days after the clinical procedure, the teeth were extracted and processed for analysis under optical microscopy. In Group 1 in which the average for the remaining dentin thickness (RDT) between the cavity floor and the coronal pulp was 909.5 μm, a discrete inflammatory response occurred in only one specimen with an RDT of 214 μm. However, tissue disorganization occurred in most specimens. In Group 2 (average RDT = 935.2 μm), the discrete inflammatory pulp response was observed in only one specimen (average RDT = 413 μm). It may be concluded that the high-speed air-turbine handpiece caused greater structural alterations in the pulp, although without inducing inflammatory processes.

  12. 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.

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

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter

    2012-01-01

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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Analysis of Temperature Fields of High-speed Centripetal Thrust Ball Bearing%高速向心推力球轴承温度场分析

    Institute of Scientific and Technical Information of China (English)

    涂亦虓; 马希直

    2012-01-01

    轴承作为重要热源,对系统工作时的温度上升产生重要影响.分别采用热网络法和有限体积法,对高速向心推力球轴承的稳态温度场进行分析计算.比较两种算法的优劣,获得其稳态温度分布场,总结出诸如转速、预紧载荷等因素对轴承温升的影响规律,为合理选择轴承参数,提高其工作可靠性提供理论依据.%The bearing is considered as the important heat source, It has great influence on the temperature rise during working . In this paper, the transient and steady temperature fields of the high-speed centripetal thrust ball bearing are analysised based on thermal network analysis & finite volume method. Ultimately, steady-state temperature fields are built. As compared with these two methods, this paper sums up the influence law caused by the speed, load and other factors, in order to select the perfect bearing parameter and provide the theoretical basis of the working reliability.

  19. Parametric Variations Sensitivity Analysis on IM Discrete Speed Estimation

    Directory of Open Access Journals (Sweden)

    Mohamed BEN MESSAOUD

    2007-09-01

    Full Text Available Motivation: This paper will discuss sensitivity issues in rotor speed estimation for induction machine (IM drives using only voltage and current measurements. A supervised estimation algorithm is proposed with the aim to achieve good performances in the large variations of the speed. After a brief presentation on discrete feedback structure of the estimator formulated from d-q axis equations, we will expose its performances for machine parameters variations.Method: Hyperstability concept was applied to the synthesis adaptation low. A heuristic term is added to the algorithm to maintain good speed estimation factor in high speeds.Results: In simulation, the estimation error is maintained relatively low in wide range of speeds, and the robustness of the estimation algorithm is shown for machine parametric variations.Conclusions: Sensitivity analysis to motor parameter changes of proposed sensorless IM is then performed.

  20. 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.

  1. Magnet loss analysis for a high-speed PM machine with segmented PM and modified tooth-tips shape

    Directory of Open Access Journals (Sweden)

    Mlot Adrian

    2016-12-01

    Full Text Available This paper presents the loss-oriented performance analysis of a radial highspeed permanent magnet (PM machine with concentrated windings for automotive application. The PM synchronous machine was designed for an operating frequency up to 800 Hz. The main aim of this paper is to analyse the selected methods for magnet eddycurrent loss reduction. The first approach to rotor modification regards magnet segmentation in circumferential and axial directions. The second approach is based on changes in tooth-tips shape of the stator. The best variants of tooth-tip shapes are determined for further investigation, and adopted with a rotor having magnet segmentation. It is found that the machine with a segmented magnet leads to magnet loss reduction by 81%. Further loss reduction by 45% can be realized with the proposed tooth-tip shape. Additionally, owing to the stator and rotor modifications, the main machine parameters are investigated, such as back-EMF, electromagnetic torque, torque ripple and cogging torque. The 2-D and 3-D finite element analysis (FEA is used for electromagnetic analysis. An experimental approach based on a partially wound stator is employed to verify the 3-D FEA.

  2. TEHL analysis of high-speed and heavy-load roller bearing with quasi-dynamic characteristics

    Directory of Open Access Journals (Sweden)

    Shi Xiujiang

    2015-08-01

    Full Text Available In this paper, the aero-engine mainshaft roller bearing D1842926 under typical operating conditions is taken as a case study, a new integrated numerical algorithm of quasi-dynamics and thermal elastohydrodynamic lubrication (TEHL is put forward, which can complete the bearing lubricated analysis from global dynamic performance to local TEHL state and break out of the traditional analysis way carried out independently in their own field. The 3-D film thickness distributions with different cases are given through integrated numerical algorithm, meanwhile the minimum film thickness of quasi-dynamic analysis, integrated numerical algorithm and testing are compared, which show that integrated numerical results have good agreements with the testing data, so the algorithm is demonstrated available and can judge the lubrication state more accurately. The parameter effects of operating and structure on pv value, cage sliding rate, TEHL film pressure, thickness and temperature are researched, which will provide an important theoretical basis for the structure design and optimization of aero-engine mainshaft roller bearing.

  3. Unified aeroacoustics analysis for high speed turboprop aerodynamics and noise. Volume 2: Development of theory for wing shielding

    Science.gov (United States)

    Amiet, R. K.

    1991-01-01

    A unified theory for aerodynamics and noise of advanced turboprops is presented. The theory and a computer code developed for evaluation at the shielding benefits that might be expected by an aircraft wing in a wing-mounted propeller installation are presented. Several computed directivity patterns are presented to demonstrate the theory. Recently with the advent of the concept of using the wing of an aircraft for noise shielding, the case of diffraction by a surface in a flow has been given attention. The present analysis is based on the case of diffraction of no flow. By combining a Galilean and a Lorentz transform, the wave equation with a mean flow can be reduced to the ordinary equation. Allowance is also made in the analysis for the case of a swept wing. The same combination of Galilean and Lorentz transforms lead to a problem with no flow but a different sweep. The solution procedures for the cases of leading and trailing edges are basically the same. Two normalizations of the solution are given by the computer program. FORTRAN computer programs are presented with detailed documentation. The output from these programs compares favorably with the results of other investigators.

  4. Study on the saturation characteristics of high-speed uni-traveling-carrier photodiodes based on field screening analysis

    Institute of Scientific and Technical Information of China (English)

    Tuo Shi; Bing Xiong; Changzheng Sun; Yi Luo

    2011-01-01

    A back-illuminated mesa-Structure InGaAs/InP charge-compensated uni-traveling-carrier (UTC) photodi-ode (PD) is fabricated, and its saturation characteristics are investigated. The responsivity of the 40-μm-diameter PD is as high as 0.83 A/W, and the direct current (DC) saturation current is up to 275 mA. The 1-dB compression point at the 3-dB cutoff frequency of 9 GHz is measured to be 100 mA, corresponding to an output radio frequency (RP) power of up to 20.1 dBm. According to the calculated electric field distributions in the depleted region under both DC and alternating current (AC) conditions, the saturation of the UTC-PD is caused by complete field screening at high optical injection levels.%@@ A back-illuminated mesa-structure InGaAs/InP charge-compensated uni-traveling-carrier(UTC) photodiode(PD) is fabricated,and its saturation characteristics are investigated.The responsivity of the 40-μmdiameter PD is as high as 0.83 A/W,and the direct current(DC) saturation current is up to 275 Ma.

  5. 韩国高速铁路发展及管理模式%Brief Analysis on Development and Management Mode of South Korean High Speed Railway

    Institute of Scientific and Technical Information of China (English)

    凌晨

    2016-01-01

    With the past ten years of construction and development, mileage of route length of China high-speed railways ranks the first in the world, and the high speed lines in China railway network lead an important position. In 2013, China opened a new chapter in the railway reform, while South Korea as one of China's neighbors, and its railway management mode and reform has a close relationship with its development of high speed railway. The paper analyzes the development course, management mode and reform experience of Korean high speed railway, providing important reference values to the reform of China high speed railways.%通过近十年的建设发展,中国的高速铁路运营里程位居世界第一位,高速铁路在中国的路网中占有重要的位置。2013年,中国掀开铁路改革的新篇章,韩国作为邻国,其铁路管理模式与改革和高速铁路的发展有着密切关系。文章分析韩国高速铁路的发展历程、管理模式和改革经验,对中国高速铁路改革具有重要的参考价值。

  6. Design and Analysis of a High Speed, Power Efficient 8 Bit ALU Based on SOI / SON MOSFET Technology

    Directory of Open Access Journals (Sweden)

    Subhramita Basak

    2014-01-01

    Full Text Available This paper shows an overall performance comparative analysis in terms of Average Power Consumption, Average Delay and Power-Delay Product for an 8 bit Arithmetic Logic Unit (ALU using bulk MOS, Silicon-on-Insulator (SOI and Silicon-on-Nothing (SON technology. The entire design is done in 32nm technology for all the three cases (Bulk, SOI & SON and then compared. The comparisons have been carried out with the help of the simulation runs on Synopsys HSpice tool, and that clearly indicates, for lower Supply Voltages (Vdd, SOI / SON technology provides a significant reduction in Average Power Consumption, Average Delay and Power-Delay Product compared to that of Bulk MOS technology.

  7. 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.

  8. 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.

  9. 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.

  10. 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,...

  11. 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...

  12. 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…

  13. 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…

  14. 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.

  15. 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

  16. Unified aeroacoustics analysis for high speed turboprop aerodynamics and noise. Volume 4: Computer user's manual for UAAP turboprop aeroacoustic code

    Science.gov (United States)

    Menthe, R. W.; Mccolgan, C. J.; Ladden, R. M.

    1991-01-01

    The Unified AeroAcoustic Program (UAAP) code calculates the airloads on a single rotation prop-fan, or propeller, and couples these airloads with an acoustic radiation theory, to provide estimates of near-field or far-field noise levels. The steady airloads can also be used to calculate the nonuniform velocity components in the propeller wake. The airloads are calculated using a three dimensional compressible panel method which considers the effects of thin, cambered, multiple blades which may be highly swept. These airloads may be either steady or unsteady. The acoustic model uses the blade thickness distribution and the steady or unsteady aerodynamic loads to calculate the acoustic radiation. The users manual for the UAAP code is divided into five sections: general code description; input description; output description; system description; and error codes. The user must have access to IMSL10 libraries (MATH and SFUN) for numerous calls made for Bessel functions and matrix inversion. For plotted output users must modify the dummy calls to plotting routines included in the code to system-specific calls appropriate to the user's installation.

  17. 曲面多轴高速加工技术的动态分析与研究%Dynamic Analysis and Research of Curve Multiaxial High-speed Machining Technology

    Institute of Scientific and Technical Information of China (English)

    保金凤

    2011-01-01

    The article chooses curve multiaxial high-speed machining technology as research object. Considering the characteristics and realistic requirement of curve and high-speed machining based on three -axis curve machining, the article makes a dynamic analysis on curve high-speed machining, providing reference for curve multiaxial high-speed machining and improving machining quality of parts.%本文以曲面多轴高速加工技术为研究对象,在三轴曲面加工基础上考虑多轴曲面和高速切削的特点和现实要求,对曲面高速加工过程进行动态分析,为曲面多轴高速加工技术的优化提供参考,以提高加工工件的表面质量.

  18. Analysis of dynamic accumulative damage about the lining structure of high speed railway’s tunnel based on ultrasonic testing technology

    Science.gov (United States)

    Wang, Xiang-qiu; Zhang, Huojun; Xie, Wen-xi

    2017-08-01

    Based on the similar material model test of full tunnel, the theory of elastic wave propagation and the testing technology of intelligent ultrasonic wave had been used to research the dynamic accumulative damage characteristics of tunnel’s lining structure under the dynamic loads of high speed train. For the more, the dynamic damage variable of lining structure of high speed railway’s tunnel was obtained. The results shown that the dynamic cumulative damage of lining structure increases nonlinearly with the times of cumulative vibration, the weakest part of dynamic cumulative damage is the arch foot of tunnel. Much more attention should be paid to the design and operation management of high speed railway’s tunnel.

  19. Passenger Sharing of the High-Speed Railway from Sensitivity Analysis Caused by Price and Run-time Based on the Multi-Agent System

    Directory of Open Access Journals (Sweden)

    Ma Ning

    2013-09-01

    Full Text Available Purpose: Nowadays, governments around the world are active in constructing the high-speed railway. Therefore, it is significant to make research on this increasingly prevalent transport.Design/methodology/approach: In this paper, we simulate the process of the passenger’s travel mode choice by adjusting the ticket fare and the run-time based on the multi-agent system (MAS.Findings: From the research we get the conclusion that increasing the run-time appropriately and reducing the ticket fare in some extent are effective ways to enhance the passenger sharing of the high-speed railway.Originality/value: We hope it can provide policy recommendations for the railway sectors in developing the long-term plan on high-speed railway in the future.

  20. 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.

  1. 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.

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. High Speed Signal Analysis and Research to Digital System%对数字系统高速信号的分析与研究

    Institute of Scientific and Technical Information of China (English)

    张辉; 范一心

    2012-01-01

    现代数字信号系统中,信号传输的速率越来越高,当高速信号由系统输入端进入,经过系统处理加工后,再传输到输出端.那么在这个处理传输过程中,如何保证高速信号的传输质量,如何确定信号从输入到输出是完整的?通过对传输过程所涉及到的会对信号的处理与传输产生影响的方方面面,进行分析并加以验证,其中线路传输过程损耗分析和传输高速信号过程中的信号动态分析,是高速信号系统的重要分析手段,并在此分析基础上,提出解决问题的技术手段及在工程上的设计及验证实现.%In the modern digital system,the signal rate is getting higher and higher,when the top speed semaphore is entered by the system input port,after system transaction transform after,deliver output again to carry,during processing signal,how to guarantee the high speed signal the transmission quality or signal integrity? The article approval involves vs. the transmission process of will generate all aspects progress analysis of impact on transaction and transmission of semaphore and take into to verify,this article analyze signal loss in the trace and dynamic transmission process,provide a technical solution of this problem and give out engineer design and verification.

  7. 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.

  8. Improved pulse laser ranging algorithm based on high speed sampling

    Science.gov (United States)

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

    2016-10-01

    Narrow pulse laser ranging achieves long-range target detection using laser pulse with low divergent beams. Pulse laser ranging is widely used in military, industrial, civil, engineering and transportation field. In this paper, an improved narrow pulse laser ranging algorithm is studied based on the high speed sampling. Firstly, theoretical simulation models have been built and analyzed including the laser emission and pulse laser ranging algorithm. An improved pulse ranging algorithm is developed. This new algorithm combines the matched filter algorithm and the constant fraction discrimination (CFD) algorithm. After the algorithm simulation, a laser ranging hardware system is set up to implement the improved algorithm. The laser ranging hardware system includes a laser diode, a laser detector and a high sample rate data logging circuit. Subsequently, using Verilog HDL language, the improved algorithm is implemented in the FPGA chip based on fusion of the matched filter algorithm and the CFD algorithm. Finally, the laser ranging experiment is carried out to test the improved algorithm ranging performance comparing to the matched filter algorithm and the CFD algorithm using the laser ranging hardware system. The test analysis result demonstrates that the laser ranging hardware system realized the high speed processing and high speed sampling data transmission. The algorithm analysis result presents that the improved algorithm achieves 0.3m distance ranging precision. The improved algorithm analysis result meets the expected effect, which is consistent with the theoretical simulation.

  9. 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.)

  10. 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.

  11. SPEED design optimization via Fresnel propagation analysis

    Science.gov (United States)

    Beaulieu, Mathilde; Abe, Lyu; Martinez, Patrice; Gouvret, Carole; Dejonghe, Julien; Preis, Oliver; Vakili, Farrokh

    2016-08-01

    Future extremely large telescopes will open a niche for exoplanet direct imaging at the expense of using a primary segmented mirror which is known to hamper high-contrast imaging capabilities. The focal plane diffraction pattern is dominated by bright structures and the way to reduce them is not straightforward since one has to deal with strong amplitude discontinuities in this kind of unfriendly pupil (segment gaps and secondary support). The SPEED experiment developed at Lagrange laboratory is designed to address this specific topic along with high-contrast at very small separation. The baseline design of SPEED will combine a coronagraph and two deformable mirrors to create dark zones at the focal plane. A first step in this project was to identify under which circumstances the deep contrast at small separation is achievable. In particular, the DMs location is among the critical aspect to consider and is the topic covered by this paper.

  12. 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.

  13. High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

    Science.gov (United States)

    Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2016-02-01

    Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

  14. 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.

  15. Designing a Two-Phase BLDC Motor and Finite-Element Analysis of Designing a Controller in Order to Manoeuvre High-Speed Boats in Marine Turbulences

    Directory of Open Access Journals (Sweden)

    Mehrdad Jafarboland

    2014-01-01

    Full Text Available High speed boats are small kind of boats which are piloted with boatman.These boats are usually used in strategic commissions like military which fast speeds and good manoeuvrability are of essential importance.Rough sea path, marine turbulences and multi input multi output nonlinear dynamical model of this boats,make it very difficult to pilot and manoeuvre them.in this paper,.two controller are designed and proposed for pursuing desired path and manoeuvring fast speeds.Fuzzy controller is compared with the result of PID controller. Simulation results also indicate that these proposed controllers have suitable responses and can pilot the boat in the best manner.

  16. Signal Conditioning in Process of High Speed Imaging

    Directory of Open Access Journals (Sweden)

    Libor Hargas

    2015-01-01

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

  17. The high-speed after pulse measurement system for PMT

    CERN Document Server

    Cheng, Yaping; Ning, Zhe; Xia, Jingkai; Wang, Wenwen; Wang, Yifang; Cao, Jun; Jiang, Xiaoshan; Wang, Zheng; Li, Xiaonan; Qi, Ming; Heng, Yuekun; Liu, Shulin; Lei, Xiangcui; Wu, Zhi

    2014-01-01

    A system employing a desktop FADC has been developed to investigate the features of 8 inches Hamamatsu PMT. The system stands out for its high-speed and informative results as a consequence of adopting fast waveform sampling technology. Recording full waveforms allows us to perform digital signal processing, pulse shape analysis, and precision timing extraction. High precision after pulse time and charge distribution characteristics are presented in this manuscript. Other photomultipliers characteristics, such as dark rate and transit time spread, can also be obtained by exploiting waveform analysis using this system.

  18. 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...

  19. 高速磁浮轨道不平顺测试及分析%Measurements and analysis of track irregularities on high speed maglev lines

    Institute of Scientific and Technical Information of China (English)

    Jin SHI; Wen-shan FANG; Ying-jie WANG; Yang ZHAO

    2014-01-01

    Track irregularities have an obvious effect on the running stability and ride quality of maglev trains traveling at high speeds. We developed a measurement principle and data processing method which were applied to the high speed maglev line operating. The method, which includes partial filtering, integration, resampling of signal, and a low pass Butterworth filter, was used to calculate the irregularities of the maglev line. The spectra of the sample space were evaluated. A 7-parameter power spectrum density (PSD) function of line irregularities was fitted, based on the measured data. Analysis of the results showed that the maglev stator plane irregularities were better than conventional railway vertical rail irregularities when the wavelength was 5-100 m, and worse when the wavelength was 1-5 m. The PSD of maglev guidance plane irregularities was similar to that of cross level GRSHL (German railway spectra of high irregularity) when the wavelength was 10-100 m. The irregularities were clearly worse than cross level rail irregularities in a conventional railway when the wavelength was 1-10 m. This suggests that short-wavelength track irregularities of a maglev line caused by deviation and inclination of the stator plane should be minimized by strictly controlling the machining error of functional components during construction and maintenance.%研究目的:提出高速磁浮轨道不平顺处理方法,分析不平顺特征,拟合形成轨道谱,为线路空间维护提供参考。  创新要点:实现了对高速磁浮轨道不平顺的提取,确定了轨道谱参数。  研究方法:基于惯性基准法,运用数字信号处理方法实现对轨道不平顺的提取,采用最小二乘法拟合得到定子面和导向面七参数轨道谱。  重要结论:定子面和导向面分别在5-100 m和10-100 m波长范围内平顺性状态较好,由功能件安装等引起的1-5 m和1-10 m波长范围内的偏差应严格控制。

  20. Dynamic High-speed Knotting of a Rope by a Manipulator

    Directory of Open Access Journals (Sweden)

    Yuji Yamakawa

    2013-10-01

    Full Text Available In this paper we suggest an entirely new strategy for the dexterous manipulation of a linear flexible object, such as rope or a cable, with a high-speed manipulator. We deal with a flexible rope as one example of the linear flexible object. The strategy involves manipulating the object at high-speed. By moving the robot at high-speed, we can assume that the dynamic behaviour of the flexible rope can be obtained by performing algebraic calculations of the high- speed robot motion. Based on this assumption, we derive a dynamic deformation model of the flexible rope and confirm the validity of the proposed model. Then we perform a simulation of dynamic, high-speed knotting based on the proposed model. We also discuss the possibility of forming the knot based on a simple analysis model. Finally, we show experimental results demonstrating dynamic, high-speed knotting with a high-speed manipulator.

  1. Safety of high speed magnetic levitation transportation systems. Magnetic field testing of the TR07 Maglev vehicle and system. Volume 1: Analysis

    Science.gov (United States)

    Dietrich, Fred; Feero, William E.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic field (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposure to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Analysis summarizes the experimental findings and compares results to common home, work, and power lines emissions for selected spectral bands.

  2. Plastic Zone Analysis of Deep-Buried, Noncircular Tunnel and Application on the High-Speed Railway in the Karst Area

    Directory of Open Access Journals (Sweden)

    Hai Shi

    2017-01-01

    Full Text Available With the conformal mapping function provided by Verruijt, the outland of a noncircular tunnel can be mapped to a circular unit in the complex plane and then spread the analytic function into a Laurent series. The stress unified solution of oval and horseshoe cross section can be determined using Muskhelishvili’s complex variables function method. Subsequently, the solution can be taken into the Griffith strength failure criterion and determine the scale and shape of plastic zone in the tunnel surrounding rock. Aiming at the critical safety thickness between a concealed cave and tunnel in the karst area and determining whether the plastic zone of tunnel surrounding rock is connected with the plastic zone of cave as a judgment standard, the model of critical safety thickness among the concealed caves and tunnels is established. The numerical model is established in comparison with the computing method of rock plate critical safety thickness in actual engineering based on the Doumo tunnel engineering of Shanghai-Kunming (Guizhou segment high-speed railway. The following conclusions can be drawn: the analytical approximation method has less indexes, and the output of this method is approximately close to actual engineering and numerical analysis, in which it is reliable and rational.

  3. 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.

  4. 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.

  5. 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.

  6. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. (Los Alamos National Lab., NM (United States)); Levine, G.F. (California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services)

    1993-01-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  7. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. [Los Alamos National Lab., NM (United States); Levine, G.F. [California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services

    1993-05-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  8. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. [Los Alamos National Lab., NM (United States); Levine, G.F. [California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services

    1993-05-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

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

    Science.gov (United States)

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

    2017-01-01

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

  10. High Speed Photography What Role Does It Play In Mining?

    Science.gov (United States)

    Crosby, William A.

    1987-09-01

    High speed photography is being employed to help improve the efficiency of a number of different mining activities. Its principal use, however, is as an aid in the optimization of blasting operations. Blasts are commonly of very short duration and great benefit can thus be gained by being able to observe the events at a suitably selected slow motion over an extended period of time. This paper presents an overview of some of the high speed photographic applications in both surface and underground operations using qualitative and quantitative techniques. The primary use is the direct photography of the blast, the analysis of the resulting films representing the bulk of the optimization work. Other applications are designed to check out individual blast components, particularly evaluating blast tamping, and actual delay element times for such accessories as detonating relays, down-the-hole delays and other delaying and initiating systems.

  11. 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

  12. Comparing Terminal Performance of .357 SIG and 9mm Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

    CERN Document Server

    Keys, Elizabeth; Courtney, Michael

    2015-01-01

    High-speed video has emerged as an valuable tool for quantifying bullet performance in ballistic gelatin. This paper presents the results of testing four .357 SIG bullets using high-speed video of bullet impacts in ballistic gelatin to determine retarding force curves, permanent cavities, temporary cavities, and energy deposit vs. penetration depth. Since the methods are identical, results are meaningfully compared with four 9mm NATO bullets studied in an earlier project. Though .357 SIG bullets perform slightly better due to higher impact energy, the principal finding is that there is a much bigger difference in performance between the best and worst performing bullets in each cartridge than there is between bullets of similar design in the two cartridges. In each cartridge, higher performing expanding bullets (jacketed hollow points) outperform non-expanding bullets (full metal jacket) by a wide margin, showing a much higher probability of rapid incapacitation according to an Army Research Laboratory model ...

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  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. High speed electrical transmission line design and characterization

    Science.gov (United States)

    Bates, R.; Buttar, C.; Buytaert, J.; Eklund, L.; de Acedo, L. F. S.; Longstaff, I.; Naik, S.; Sullivan, S.; Wraight, K.

    2017-02-01

    High Energy Physics (HEP) experiments have unique requirements for data communication. High data speeds, combined with extreme restrictions on materials allowed, leads to custom transmission lines. This paper will present transmission line design theory, simulation and testing methods. Transmission line designs options like flexes and rigid PCBs as well as cables will be studied. Finite Element Analysis (FEA) software packages simulate energy dissipation and quality of transmitted signals. The characterisation techniques of time-domain reflectometry and frequency-domain measurements are discussed and compared. Bit-error-rate testing is presented and its limitations for design discussed. Methods to improve quality, like three different types of equalization are described.

  19. 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...

  20. 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.

  1. Hazard Avoidance for High-Speed Mobile Robots in Rough Terrain

    Science.gov (United States)

    2006-05-01

    Accepted to the Journal of Field Robotics 1 Hazard Avoidance for High-Speed Mobile Robots in Rough Terrain Matthew Spenko, Yoji Kuroda, Steven...COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Hazard Avoidance for High-Speed Mobile Robots in Rough Terrain 5a. CONTRACT NUMBER 5b...Fundamentals of vehicle dynamics. Warrendale, PA: Society of Automotive Engineers. Golda, D. (2003). Modeling and analysis of high-speed mobile robots operating

  2. Complex configuration analysis at transonic speeds

    Science.gov (United States)

    Boppe, C. W.; Aidala, P. V.

    1980-01-01

    Advanced performance requirements of new combat and transport aircraft together with design time constraints intensify the development and application of three dimensional computational analyses. A computational method which was developed for the specific purpose of providing an engineering analysis of complex aircraft configurations at transonic speeds. Particular attention is given to the recently incorporated wing viscous interaction and canard capabilities. The treatment of fuselage fairings, nacelles, and pylons is reviewed. The means for keeping computing resources at reasonable levels are identified. Three configurations were selected for correlations with experimental data. Taken together, the comparisons illustrate the full extent of current analysis capabilities. The configurations include: (1) a wing fuselage canard fighter; (2) a transport with fuselage fairings, four nacelles, four pylons; and (3) a space vehicle which includes an external fuel tank and rocket boosters (transonic launch configuration).

  3. 某种高速冲床外购件的可靠性分析与研究%Analysis and research of purchased parts reliability for certain high-speed punch

    Institute of Scientific and Technical Information of China (English)

    张根保; 陈宥宇; 张会杰; 孙晓丁

    2012-01-01

    为提升高速冲床整体可靠性水平,将所含外购件视为整体,分析了高速冲床外购件对整机影响,建立了高速冲床外购件双重威布尔分段模型,计算时间拐点并检验,分别进行早期失效期、偶然失效期FMEA对比分析,提出了高速冲床外购件关键控制技术.同时,作为共性技术,对其它高速冲压设备外购件可靠性分析与控制具有指导意义.%In order to enhance the entire reliability of high-speed punch, the purchased parts were considered as a whole. The influence of purchased parts on high-speed punch was analyzed. Sectional model involving two Weibull distributions of purchased parts in high-speed punch was established. The calculation and test on inflection point were implemented. The FMEA of the early failure period and the random failure period were compared. And the key control technology on purchased parts of high-speed punch was proposed which is significant in reliability analysis and control of purchased parts in other high-speed punching machines.

  4. A high-speed BCI based on code modulation VEP

    Science.gov (United States)

    Bin, Guangyu; Gao, Xiaorong; Wang, Yijun; Li, Yun; Hong, Bo; Gao, Shangkai

    2011-04-01

    Recently, electroencephalogram-based brain-computer interfaces (BCIs) have attracted much attention in the fields of neural engineering and rehabilitation due to their noninvasiveness. However, the low communication speed of current BCI systems greatly limits their practical application. In this paper, we present a high-speed BCI based on code modulation of visual evoked potentials (c-VEP). Thirty-two target stimuli were modulated by a time-shifted binary pseudorandom sequence. A multichannel identification method based on canonical correlation analysis (CCA) was used for target identification. The online system achieved an average information transfer rate (ITR) of 108 ± 12 bits min-1 on five subjects with a maximum ITR of 123 bits min-1 for a single subject.

  5. 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

  6. 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

  7. Thermal analysis of high speed permanent magnet brushless DC motor%高速永磁无刷直流电机的热分析

    Institute of Scientific and Technical Information of China (English)

    杜国华; 房建成; 刘西全; 周银锋

    2012-01-01

    为了解决高速永磁无刷直流电机温升过高带来的磁性能降低及绕组绝缘破坏等问题,对高速电机的温度分布及改进措施进行了一系列研究.采用集中参数法建立了电机热网络数学模型,推导出电机损耗、热导和温度之间的解析方程;建立了基于ANSYS/Work-bench的电机三维有限元模型,对其进行稳态热分析,从而得到电机整体的温度分布,验证了电机热网络模型的正确性;提出了改变转子护套材料及电机轴打孔两种措施.分析结果表明:改进后的电机转子部分温度有了明显降低,其中护套温度降低了约34℃,永磁体约54℃,解决了电机的局部温度过高问题.%In order to solve the problems of reduction in magnetic performance and winding insulation damage caused by high temperature in high speed permanent magnet brushless DC motor, a series of research on temperature distribution and improvement was carried out. The thermal network mathematic model was established by lumped parameters method. And an analytic equation accounting for the relationship among motor loss, thermal conductance and temperature was derived. Besides, the motor 3D finite element model was built based on the ANSYS/Workbench, and steady-state analysis was conducted. The temperature distribution of the whole motor was achieved, which verified the results of thermal network model. And two methods inclu- ding changing the retaining sleeve material and drilling holes on shaft were proposed to solve the temperature problem. According to the analysis results the rotor temperature has dropped obviously, especially the retaining sleeve and permanent magnet with a temperature decrease of about 54℃and 54℃ respectively.

  8. Nonlinear analysis of wind-induced vibration of high-speed railway catenary and its influence on pantograph-catenary interaction

    Science.gov (United States)

    Song, Yang; Liu, Zhigang; Wang, Hongrui; Lu, Xiaobing; Zhang, Jing

    2016-06-01

    The wind-induced vibration of the high-speed catenary and the dynamic behaviour of the pantograph-catenary under stochastic wind field are firstly analysed. The catenary model is established based on nonlinear cable and truss elements, which can fully describe the nonlinearity of each wire and the initial configuration. The model of the aerodynamic forces acting on the messenger/contact wire is deduced by considering the effect of the vertical and horizontal fluctuating winds. The vertical and horizontal fluctuating winds are simulated by employing the Davenport and Panofsky spectrums, respectively. The aerodynamic coefficients of the contact/messenger wire are calculated through computational fluid dynamics. The wind-induced vibration response of catenary is analysed with different wind speeds and angles. Its frequency-domain characteristics are discussed using Auto Regression model. Finally, a pantograph model is introduced and the contact force of the pantograph-catenary under stochastic wind is studied. The results show that both the wind speed and the attack angle exert a significant effect on the wind-induced vibration. The existence of the groove on the contact wire cross-section leads to a significant change of the aerodynamic coefficient, which affects largely the aerodynamic forces applied on the catenary wires, as well as the vibration response. The vibration frequency with high spectral power mainly concentrates on the predominant frequency of the fluctuating wind and the natural frequency of catenary. The increase in the wind speed results in a significant deterioration of the current collection. The numerical example shows that a relatively stable current collection can be ensured when the wind flows at the relatively horizontal direction.

  9. 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.

  10. 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.

  11. High speed stamping thermal analysis of automotive covering parts and tis application in synchronous engineering%汽车覆盖件高速冲压热分析及其在同步工程中的应用

    Institute of Scientific and Technical Information of China (English)

    刘志氏; 覃开宇; 何述平; 陈立军; 赵凌云

    2012-01-01

    从板料成形时热效应方面出发,推导了板料高速冲压时温升的理论计算公式,研究了高速冲压成形时板料内部的温度分布云图,结合高速冲压生产时出现的产品缺陷与模具失效分析,提出一种基于热分析的同步工程分析方法,为汽车覆盖件高速冲压生产技术研究奠定理论基础。%From the thermal effects when sheet metal forming,deduce calculation of theoretic for temperature raising in high speed stamping,research the temperature distribution cloud for sheet metal interior in high speed stamp modeling,combine the product defects and mold failure analysis appears in high speed stamp production.Put forward synchronous engineering analysis method based on thermal analysis,provide theoritical foundation for production technology research of automotive covering parts high speed stamping.

  12. 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.

  13. 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...

  14. High speed digital holographic interferometry for hypersonic flow visualization

    Science.gov (United States)

    Hegde, G. M.; Jagdeesh, G.; Reddy, K. P. J.

    2013-06-01

    Optical imaging techniques have played a major role in understanding the flow dynamics of varieties of fluid flows, particularly in the study of hypersonic flows. Schlieren and shadowgraph techniques have been the flow diagnostic tools for the investigation of compressible flows since more than a century. However these techniques provide only the qualitative information about the flow field. Other optical techniques such as holographic interferometry and laser induced fluorescence (LIF) have been used extensively for extracting quantitative information about the high speed flows. In this paper we present the application of digital holographic interferometry (DHI) technique integrated with short duration hypersonic shock tunnel facility having 1 ms test time, for quantitative flow visualization. Dynamics of the flow fields in hypersonic/supersonic speeds around different test models is visualized with DHI using a high-speed digital camera (0.2 million fps). These visualization results are compared with schlieren visualization and CFD simulation results. Fringe analysis is carried out to estimate the density of the flow field.

  15. 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.

  16. Bottom Raking Damage to High-Speed Craft

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    This paper presents a comparative study of the raking damage to high speed craft (HSC) and conventional ships. The analysis is based on a detailed theoretical model for the raking resistance of an assembled ship bottom structure and on the idea that the impact conditions for various ship types have...... certain similarities. Thus, damage statistics for one ship type can be scaled to another ship type.The result of a raking damage calculation is sensitive to various uncertain parameters, such as the impact velocity and the rock height and shape. Conveniently, the paper shows that the damage scaling factor...

  17. 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.

  18. 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.

  19. 高速铁路隧道内信号接口条件分析%Condition Analysis of Signal Interface for High Speed Railway Line in Tunnel

    Institute of Scientific and Technical Information of China (English)

    陈志颖

    2011-01-01

    从高速铁路信号系统在长大隧道内的设备安装及中继站设置的条件出发,说明预留接口条件的因素,提出相关接口预留方案,对其他相关线路设计起到指导作用。%Started from the conditions of installing equipment and setting of repeater station of high speed railway signal system in long tunnels,this paper mainly explained the reserved interface conditions and gave the reservation solution of relevant interfaces,

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. High-speed digital phonoscopy images analyzed by Nyquist plots

    Science.gov (United States)

    Yan, Yuling

    2012-02-01

    Vocal-fold vibration is a key dynamic event in voice production, and the vibratory characteristics of the vocal fold correlate closely with voice quality and health condition. Laryngeal imaging provides direct means to observe the vocal fold vibration; in the past, however, available modalities were either too slow or impractical to resolve the actual vocal fold vibrations. This limitation has now been overcome by high-speed digital imaging (HSDI) (or high-speed digital phonoscopy), which records images of the vibrating vocal folds at a rate of 2000 frames per second or higher- fast enough to resolve a specific, sustained phonatory vocal fold vibration. The subsequent image-based functional analysis of voice is essential to better understanding the mechanism underlying voice production, as well as assisting the clinical diagnosis of voice disorders. Our primary objective is to develop a comprehensive analytical platform for voice analysis using the HSDI recordings. So far, we have developed various analytical approaches for the HSDI-based voice analyses. These include Nyquist plots and associated analysese that are used along with FFT and Spectrogram in the analysis of the HSDI data representing normal voice and specific voice pathologies.

  6. 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.

  7. High speed electric motors based on high performance novel soft magnets

    Science.gov (United States)

    Silveyra, J. M.; Leary, A. M.; DeGeorge, V.; Simizu, S.; McHenry, M. E.

    2014-05-01

    Novel Co-based soft magnetic materials are presented as a potential substitute for electrical steels in high speed motors for current industry applications. The low losses, high permeabilities, and good mechanical strength of these materials enable application in high rotational speed induction machines. Here, we present a finite element analysis of Parallel Path Magnetic Technology rotating motors constructed with both silicon steel and Co-based nanocomposite. The later achieved a 70% size reduction and an 83% reduction on NdFeB magnet volume with respect to a similar Si-steel design.

  8. 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...

  9. 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.

  10. 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...

  11. An analysis of peak pelvis rotation speed, gluteus maximus and medius strength in high versus low handicap golfers during the golf swing.

    Science.gov (United States)

    Callaway, Sarahann; Glaws, Kate; Mitchell, Melissa; Scerbo, Heather; Voight, Michael; Sells, Pat

    2012-06-01

    The kinematic sequence of the golf swing is an established principle that occurs in a proximal-to-distal pattern with power generation beginning with rotation of the pelvis. Few studies have correlated the influence of peak pelvis rotation to the skill level of the golfer. Furthermore, minimal research exists on the strength of the gluteal musculature and their ability to generate power during the swing. The purpose of this study was to explore the relationship between peak pelvis rotation, gluteus medius and gluteus maximus strength, and a golfer's handicap. 56 healthy subjects. Each subject was assessed using a hand-held dynamometry device per standardized protocol to determine gluteus maximus and medius strength. The K-vest was placed on the subject with electromagnetic sensors at the pelvis, upper torso, and gloved lead hand to measure the rotational speed at each segment in degrees/second. After K-vest calibration and 5 practice swings, each subject hit 5 golf balls during which time, the sensors measured pelvic rotation speed. A one-way ANOVA was performed to determine the relationships between peak pelvis rotation, gluteus medius and gluteus maximus strength, and golf handicap. A significant difference was found between the following dependent variables and golf handicap: peak pelvis rotation (p=0.000), gluteus medius strength (p=0.000), and gluteus maximus strength (p=0.000). Golfers with a low handicap are more likely to have increased pelvis rotation speed as well as increased gluteus maximus and medius strength when compared to high handicap golfers. The relationships between increased peak pelvis rotation and gluteus maximus and medius strength in low handicap golfers may have implications in designing golf training programs. Further research needs to be conducted in order to further explore these relationships.

  12. 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.

  13. 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)...

  14. 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)...

  15. 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...

  16. Feasibility analysis and demonstration of high-speed digital imaging using micro-arrays of vertical cavity surface-emitting lasers

    Science.gov (United States)

    Mentzer, Mark A.; Ghosh, Chuni L.; Guo, Baiming; Brewer, Kristopher; Nicolai, Robin; Herr, Douglas; Lubking, Carl; Ojason, Neil; Tangradi, Edward; Tarpine, Howard

    2011-04-01

    Previous laser illumination systems at Aberdeen Proving Ground and elsewhere required complex pulse timing, extensive cooling, large-scale laser systems (frequency-doubled flash-pumped Nd:YAG, Cu-vapor, Q-switched ruby), making them difficult to implement for range test illumination in high speed videography. Requirements to illuminate through the self-luminosity of explosive events motivate the development of a high brightness imaging technique obviating the limitations of previous attempts. A lensed vertical cavity surface-emitting laser array is proposed and implemented with spectral filtering to effectively remove self-luminosity and the fireball from the image, providing excellent background discrimination in a variety of range test scenarios.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. Sensitivity analysis of the critical speed in railway vehicle dynamics

    Science.gov (United States)

    Bigoni, D.; True, H.; Engsig-Karup, A. P.

    2014-05-01

    We present an approach to global sensitivity analysis aiming at the reduction of its computational cost without compromising the results. The method is based on sampling methods, cubature rules, high-dimensional model representation and total sensitivity indices. It is applied to a half car with a two-axle Cooperrider bogie, in order to study the sensitivity of the critical speed with respect to the suspension parameters. The importance of a certain suspension component is expressed by the variance in critical speed that is ascribable to it. This proves to be useful in the identification of parameters for which the accuracy of their values is critically important. The approach has a general applicability in many engineering fields and does not require the knowledge of the particular solver of the dynamical system. This analysis can be used as part of the virtual homologation procedure and to help engineers during the design phase of complex systems.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. High-speed, high-voltage pulse generation using avalanche transistor

    Science.gov (United States)

    Yong-sheng, Gou; Bai-yu, Liu; Yong-lin, Bai; Jun-jun, Qin; Xiao-hong, Bai; Bo, Wang; Bing-li, Zhu; Chuan-dong, Sun

    2016-05-01

    In this work, the conduction mechanism of avalanche transistors was demonstrated and the operation condition for generating high-speed pulse using avalanche transistors was illustrated. Based on the above analysis, a high-speed and high-voltage pulse (HHP) generating circuit using avalanche transistors was designed, and its working principle and process were studied. To improve the speed of the output pulse, an approach of reducing the rise time of the leading edge is proposed. Methods for selecting avalanche transistor and reducing the parasitic inductance and capacitance of printed circuit board (PCB) were demonstrated. With these instructions, a PCB with a tapered transmission line was carefully designed and manufactured. Output pulse with amplitude of 2 kV and rise time of about 200 ps was realized with this PCB mounted with avalanche transistors FMMT417, indicating the effectiveness of the HHP generating circuit design.

  8. Cadence® High High-Speed PCB Design Flow Workshop

    CERN Document Server

    2006-01-01

    Last release of Cadence High-Speed PCB Design methodology (PE142) based on Concept-HDL schematic editor, Constraint Manager, SPECCTRAQuest signal integrity analysis tool and ALLEGRO layout associated with SPECCTRA auto router tools, is now enough developed and stable to be taken into account for high-speed board designs at CERN. The implementation of this methodology, build around the new Constraint Manager program, is essential when you have to develop a board having a lot of high-speed design rules such as terminated lines, large bus structures, maximum length, timing, crosstalk etc.. that could not be under control by traditional method. On more conventional designs, formal aspect of the methodology could avoid misunderstanding between hardware and ALLEGRO layout designers, minimizing prototype iteration, development time and price. The capability to keep trace of the original digital designer intents in schematic or board layout, loading formal constraints in EDMS, could also be considered for LHC electro...

  9. 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.

  10. FPGA Flash Memory High Speed Data Acquisition

    Science.gov (United States)

    Gonzalez, April

    2013-01-01

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

  11. HIGH SPEED MOTORIZED SPINDLE BEARING THERMAL ANALYSIS AND EXPERIMENTAL RESEARCH%高速电主轴轴承热分析与实验研究

    Institute of Scientific and Technical Information of China (English)

    康辉民; 陈小安; 陈文曲; 周明红; 邢利娜

    2011-01-01

    The angular contact ball bearings' rolling elements' movement is utilized to study their force states in a high speed motorized spindle system, while the Gyro torque balancing effect of the bearing pre-load on rolling elements when the spindle rotates at high speed is considered. Palmgren empirical formula is used to calculate the overall friction heat of bearings, then a bearing thermal model based on heat transfer theory is established and a thermal resistance network diagram is set up by applying the thermal network method. Finally, a 120MD60Y6 mist spindle with angular contact ball bearings is used for experimental validation. The results show that the bearing temperature is mainly affected by the speed, the lubricant volume, the air supply pressure and loads, that the initial start stages of the spindle have the fastest increases in temperature, and that both the lubricant volume and the air supply pressure have an optimum range being suitable for the bearing temperature.%根据高速电主轴角接触球轴承中滚动体的运动情况,分析其受力状态,并考虑轴承预加载荷对滚动体在高速旋转状态下陀螺力矩的平衡效果,应用Palmgren经验公式计算轴承整体的摩擦热,然后依据传热学理论建立轴承的温升热模型,并用热网络法建立其热阻抗网络图,最后用120MD60Y6油雾润滑型电主轴的轴承进行试验验证.结果表明,轴承温升主要受转速、润滑油量、供气压力及载荷的影响,在主轴启动的初始阶段温升变化最快,且润滑油量和供气压力对轴承温升有一个最佳的适用范围.

  12. Análisis cinemático mediante videografía de alta velocidad en la displasia de cadera canina - Kinematic analysis using high speed videography in canine hip dysplasia

    Directory of Open Access Journals (Sweden)

    Vilar, JM

    2010-01-01

    Full Text Available ResumenEl objetivo de este trabajo consiste en proporcionar aquellos parámetros lineares, angulares y temporales en un perro de raza bulldog con displasia de cadera mediante el analisis cinematico con videografía de alta velocidad.SummaryThe purpose of this paper is to provide linear,angular and temporal parameters of a bulldog with hip dysplasia. The analysis was performed using high speed videography

  13. Análisis cinemático mediante videografía de alta velocidad en la displasia de cadera canina - Kinematic analysis using high speed videography in canine hip dysplasia

    OpenAIRE

    Vilar, JM; Morales M; Morales, I.; F. Miró; Martinez, A; Rodríguez, O

    2012-01-01

    ResumenEl objetivo de este trabajo consiste en proporcionar aquellos parámetros lineares, angulares y temporales en un perro de raza bulldog con displasia de cadera mediante el analisis cinematico con videografía de alta velocidad.SummaryThe purpose of this paper is to provide linear,angular and temporal parameters of a bulldog with hip dysplasia. The analysis was performed using high speed videography.

  14. Short pulse generation and high speed communication system

    Science.gov (United States)

    Fan, Honglei

    Ultrahigh-speed optical time-division-multiplexing (TDM) transmission technologies are essential to construct ultrahigh-speed all-optical networks needed in the multimedia era. In order to realize high-speed optical TDM systems, ultra-short pulses should be generated. In this dissertation, the gain switching and mode locking techniques have been analyzed and used to produce ultra- short pulses. Gain-switched pulses with a width of ~18ps have been obtained. The theoretical analysis on gain-switching phenomena has been carried out. A new approach for the simulation of the spectrum of a gain- switched laser has been developed. The principle of mode locking has been discussed. ~6.5ps, pulses have been obtained from a monolithic mode-locked distributed Bragg reflector (DBR) laser, which are the shortest pulses from the actively mode- locked DBR lasers as we know. ~1.1ps pulses have been achieved from a colliding-pulse mode-locked (CPM) laser. The operation principle of CPM lasers has been discussed. Pulse compression using dispersion-compensating fiber has been applied in order to get shorter pulses. The semiconductor optical amplifier (SOA) plays a very important role in TDM systems. The cross gain modulation (XGM) measurements on a 2-section SOA, using both cw and pulsed pump and probe beams, have been performed. A theoretical analysis has been carried out. Wavelength conversion and fiber transmission experiments have been achieved at different bit rates. The basic idea of TDM system has been discussed. Multiplexing has been achieved using fibers. Demulitplexing has been demonstrated using XGM in SOA, four-wave mixing (FWM) in SOA, and cascaded modulators. The operation principles have been discussed in detail. The FWM experiments between two optical pulses have been performed.

  15. High speed serdes devices and applications

    CERN Document Server

    Stauffer, David R; Sorna, Michael A; Dramstad, Kent; Ogilvie, Clarence Rosser; Amanullah, Mohammad; Rockrohr, James Donald

    2008-01-01

    Offers an understanding of the features and functions typically found on HSS devices. This book explains how these HSS devices are used in protocol applications and the analysis which must be performed to use such HSS devices.

  16. 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.

  17. Numerical Simulation of Oil Jet Lubrication for High Speed Gears

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli

    2015-01-01

    Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

  18. Performance Test and Analysis Method of High-Speed Ball Screw%高速滚珠丝杠副性能试验与分析方法研究

    Institute of Scientific and Technical Information of China (English)

    屠国俊; 陶卫军; 冯虎田; 殷爱华

    2012-01-01

    基于自主开发的性能试验台,对高速滚珠丝杠副的性能试验与分析方法进行了研究.介绍了高速滚珠丝杠副性能试验系统的构成,提出了性能试验的方法;在此基础上,进一步对试验数据的分析方法进行了研究;针对指定型号的高速滚珠丝杠副进行了性能试验,并对试验得到的数据进行了具体分析,试验与分析结果验证了所提出方法的有效性.%Based on the developed performance test system, the test and analysis method of high-speed ball screw are researched. First, the performance test system of the high-speed ball screw is introduced and a performance test method is proposed. And then, the analysis method of the test data is studied. Further, the performance test of the designated high-speed ball screw is done and the test data on highspeed ball screw is analyzed, the test and analysis results show that the proposed method is effective.

  19. 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.

  20. Passive control of rotorcraft high-speed impulsive noise

    Science.gov (United States)

    Szulc, O.; Doerffer, P.; Tejero, F.

    2016-10-01

    A strong, normal shock wave, terminating a local supersonic area located at the tip of a helicopter blade, not only limits the aerodynamic performance, but also constitutes an origin of the High-Speed Impulsive (HSI) noise. The application of a passive control device (a shallow cavity covered by a perforated plate) just beneath the interaction region weakens the compression level, thus reducing the main source of the HSI noise. The numerical investigation based on the URANS approach and Bohning/Doerffer (BD) transpiration law (SPARC code) confirms a large potential of the new method. Two exemplary implementations, adapted to model helicopter rotors tested at NASA Ames facility in transonic conditions: Caradonna-Tung (lifting, transonic hover) and Caradonna-Laub-Tung (non-lifting, high-speed forward flight), demonstrate the possible gains in terms of the reduction of acoustic pressure fluctuations in the near-field of the blade tip. The CFD results are validated against the experimental data obtained for the reference configurations (no control), while the analysis of the passive control arrangement is based on a purely numerical research. The normal shock wave is effectively eliminated by the wall ventilation exerting a positive impact on the generated level of the HSI noise.

  1. 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.

  2. 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...

  3. 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.

  4. 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 ...

  5. 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...

  6. 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...

  7. 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.

  8. 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.

  9. 玉米种子脱粒过程高速摄影观察分析%High-speed Photograph Analysis on Threshing Process of Corn Seed

    Institute of Scientific and Technical Information of China (English)

    李心平; 马福丽; 高连兴

    2009-01-01

    为优化差速式玉米种子脱粒机脱粒系统的有关参数,进而降低玉米种子在脱粒过程中的损伤,采用高速摄影方法对单个玉米果穗喂入与脱粒过程进行了观察分析.分析结果表明:果穗在开始喂入阶段,籽粒破碎大;在脱粒起始阶段,果穗撞击强烈,越到后段,撞击越弱;果穗在正常脱粒情况下,脱下籽粒多,籽粒运动轨迹可近似为沿直辊与果穗接触点的切线方向;而果穗非正常脱粒情况下,脱下籽粒少,籽粒运动规律呈杂乱状态,没有一定飞行方向;螺旋辊的转速偏大造成果穗的非正常脱粒加大,果穗的非正常脱粒会影响果穗的脱粒质量和脱粒效率.%I n order to optimize parameters of threshing system of seed corn thresher with different speeds threshing parts, and to decrease mechanical damage of corn seed kernel in the course of threshing, the process of feeding and threshing origination of single seed corn ear was analyzed by using high-speed photograph method. The testing results show that damage rate of kernels subjected intense impact is large in the feeding origination of seed corn ear; with threshing, impact changes more and more feeble, and damage rate of kernels becomes smaller and smaller too. Under state of ordinal threshing, large amounts of kernel is threshed and the moving track of threshed kernel follows the tangent direction of contacting dot of straight roller and ear, while under state of out-of-order threshing, the amount of kernel is small and the moving of threshed kernel presents disordering. Furthermore, large rotating speed of spiral roller results in the larger out-of-order threshing of ear, which influences the threshing quality and threshing efficiency of seed corn ear.

  10. High-speed cinematography of muscle contraction.

    Science.gov (United States)

    HAUPT, R E; WALL, D M

    1962-07-13

    Motion pictures of the "twitch" of an excised frog gastrocnemius muscle taken at rates of 6000 frames per second provide a means of very accurately timing the phases. The extreme "slow motion" reveals surface phenomena not observable by other techniques. Evidence of "active relaxation" is suggested by results of frame-by-frame analysis.

  11. 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....

  12. 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.

  13. 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....

  14. Comparative Performance Analysis of XOR-XNOR Function Based High-Speed CMOS Full Adder Circuits For Low Voltage VLSI Design

    Directory of Open Access Journals (Sweden)

    Sudarshan Tiwari

    2012-05-01

    Full Text Available This paper presents comparative study of high-speed, low-power and low voltage full adder circuits. Our approach is based on XOR-XNOR design full adder circuits in a single unit. A low power and high performance 9T full adder cell using a design style called “XOR (3T” is discussed. The designed circuit commands a high degree of regularity and symmetric higher density than the conventional CMOS design style as well as it lowers power consumption by using XOR (3T logic circuits. Gate Diffusion Input (GDI technique of low-power digital combinatorial circuit design is also described. This technique helps inreducing the power consumption and the area of digital circuits while maintaining low complexity of logic design. This paper analyses, evaluates and compares the performance of various adder circuits. Severalsimulations conducted using different voltage supplies, load capacitors and temperature variation demonstrate the superiority of the XOR (3T based full adder designs in term of delay, power and powerdelay product (PDP compared to the other full adder circuits. Simulation results illustrate the superiority of the designed adder circuits against the conventional CMOS, TG and Hybrid full adder circuits in terms of power, delay and power delay product (PDP.

  15. RESEARCH ON ABRASION OF DEBRIS FLOW TO HIGH-SPEED DRAINAGE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    陈洪凯; 唐红梅; 吴四飞

    2004-01-01

    As one weak topic in research of debris flow, abrasion of debris flow shortens obviously application life of control structure composed of concrete. High-speed drainage structure, one of the most effective techniques to control giant debris flow disaster, has shortened one-third application life due to abrasion by debris flow. Based on velocity calculation method founded by two-phase theory, research of abrasion mechanism of debris flow to high-speed drainage structure was made. The mechanism includes both abrasion mechanism of homogeneous sizing and shearing mechanism of particle of debris flow to high-speed drainage trough structure. Further abrasion equations of both sizing and particle were established by Newton movement theory of debris flow. And abrasion amount formula of the high-speed drainage trough structure is set up by dimensional analysis. Amount to calculating in the formula is consistent with testing data in-situ, which is valuable in design of high-speed drainage structure.

  16. 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.

  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. Dynamic Clustering Of High Speed Data Streams

    Directory of Open Access Journals (Sweden)

    J. Chandrika

    2012-03-01

    Full Text Available We consider the problem of clustering data streams. A data stream can roughly be thought of as a transient, continuously increasing sequence of time-stamped data. In order to maintain an up-to-date clustering structure, it is necessary to analyze the incoming data in an online manner, tolerating but a constant time delay. The purpose of this study is to analyze the working of popular algorithms on clustering data streams and make a comparative analysis.

  19. 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.

  20. 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

  1. Study of fish response using particle image velocimetry and high-speed, high-resolution imaging

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richmond, M. C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mueller, R. P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gruensch, G. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2004-10-01

    Fish swimming has fascinated both engineers and fish biologists for decades. Digital particle image velocimetry (DPIV) and high-speed, high-resolution digital imaging are recently developed analysis tools that can help engineers and biologists better understand how fish respond to turbulent environments. This report details studies to evaluate DPIV. The studies included a review of existing literature on DPIV, preliminary studies to test the feasibility of using DPIV conducted at our Flow Biology Laboratory in Richland, Washington September through December 2003, and applications of high-speed, high-resolution digital imaging with advanced motion analysis to investigations of fish injury mechanisms in turbulent shear flows and bead trajectories in laboratory physical models. Several conclusions were drawn based on these studies, which are summarized as recommendations for proposed research at the end of this report.

  2. Analysis of Site Selection of Abandoned Dregs Field for Mountain High-speed Railway%山区高速铁路弃渣场选址分析

    Institute of Scientific and Technical Information of China (English)

    王明慧; 蒋树平; 张桥; 金琰

    2013-01-01

    研究目的:山区高速铁路修建过程中,由于地形复杂、设计标准高等原因,常导致弃渣量巨大,对资金、环保、工期、施工安全等有较大影响,过去有的设计由于对选址与设计原则把握不当,往往在施工阶段不得不进行变更,造成人力物力的浪费,甚至埋下安全隐患.渝万铁路90%的线路位于山区与丘陵,且穿越多个林地与水源保护区,因此如何正确合理地进行选址和设计成为一项重要的课题.研究结论:结合渝万铁路的特点,通过研究得出以下结论:(1)弃渣场应尽量减少农田耕地的占用,选址一般应远离居民区和环境敏感区,少干扰地方交通;(2)要注重地质勘察,做好防护工程,避免引发滑坡等地质灾害;(3)回填弃渣场一举两得,有条件时应尽量采用.山沟和山脚弃渣场弃渣量大,占地少,弃渣方便,应作为山区铁路弃渣场主要选址.研究成果可为今后山区高速铁路弃渣场的设置提供参考.%Research purposes: In the construction process of mountain high - speed railway, a large number of abandoned dregs are produced because of the complex terrain and high design criteria, and it has a big effects on the construction cost, environmental protection, construction period and construction safety. As the principles of the site selection and design were implemented improperly, some previous designs had to be changed in construction stage to produce the big wastes of the manpower and material resources, even bring about the hidden safety danger. The 90% tracks of Yichang - Wanzhou Railway are located in the mountain and hill areas, with crossing some forest and water resource areas. How to reasonably select the site of the abandoned dregs field and how to design it are the very important works in the construction process of the mountain high - speed railway. Research conclusions: Based on the features of the Chongqing - Wanzhou Railway, it is concluded from the study

  3. 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

  4. Induction Motor Speed Estimation by Using Spectral Current Analysis

    OpenAIRE

    2009-01-01

    An interesting application for the FFT analysis is related to the induction motor speed estimation based on spectral current analysis. The paper presents the possibility of induction motor speed estimation by using the current harmonics generated because of the rotor slots and of the eccentricity.

  5. Wavefront Sensing via High Speed DSP

    Science.gov (United States)

    Smith, J. Scott; Dean, Bruce

    2004-01-01

    Future light-weighted and segmented primary mirror systems require active optical control to maintain mirror positioning and figure to within nanometer tolerances. Current image-based wavefront sensing approaches rely on post-processing techniques to return an estimate of the aberrated optical wavefront with accuracies to the nanometer level. But the lag times between wavefront sensing, and then control, contributes to a significant latency in the wavefront sensing implementation. In this analysis we demonstrate accelerated image-based wavefront sensing performance using multiple digital signal processors (DSP's). The computational architecture is discussed as well as the heritage leading to the approach.

  6. 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...

  7. High-speed quantum networking by ship

    Science.gov (United States)

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

    2016-11-01

    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.

  8. 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.

  9. 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

  10. Thermal reliability analysis of a BLDC motor in a high-speed axial fan by the accelerated-life test and numerical methods

    Science.gov (United States)

    Hur, Jin-Huek; Lee, Tae-Gu; Moon, Sun-Ae; Lee, Sang-Jae; Yoo, Hoseon; Moon, Seung-Jae; Lee, Jae-Heon

    2008-09-01

    The thermal reliability of a closed-type BLDC motor for a high-speed fan is analyzed by an accelerated-life testing and numerical methods in this paper. Since a module and a motor part are integrated in a closed case, heat generated from a rotor in a motor and electronic components in the PCB module cannot be effectively removed to the outside. Therefore, the module will easily fail due to high temperature. The experiment for measuring the temperature and the surface heat flux of the electronic components is carried out to predict their surface temperature distributions and main heat sources. The accelerated-life test is accomplished to formulate the life equation depending on the environmental temperature. Moreover, the temperature of the PCB module is different from the environmental temperature since the heat generated from the motor cannot be effectively dissipated owing to the motor’s structure. Therefore a numerical method is used to predict the temperature of the PCB module, which is one of the life equation parameter, according to the environment. By numerically obtaining the maxima of the thermal stress and strain of the electronic components according to the operation environments with the temperature results, the fatigue cycle can be estimated.

  11. 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.

  12. High-speed detection of DNA translocation in nanopipettes.

    Science.gov (United States)

    Fraccari, Raquel L; Ciccarella, Pietro; Bahrami, Azadeh; Carminati, Marco; Ferrari, Giorgio; Albrecht, Tim

    2016-04-14

    We present a high-speed electrical detection scheme based on a custom-designed CMOS amplifier which allows the analysis of DNA translocation in glass nanopipettes on a microsecond timescale. Translocation of different DNA lengths in KCl electrolyte provides a scaling factor of the DNA translocation time equal to p = 1.22, which is different from values observed previously with nanopipettes in LiCl electrolyte or with nanopores. Based on a theoretical model involving electrophoresis, hydrodynamics and surface friction, we show that the experimentally observed range of p-values may be the result of, or at least be affected by DNA adsorption and friction between the DNA and the substrate surface.

  13. 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

  14. 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

  15. 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, ""

  16. High-speed particle image velocimetry near surfaces.

    Science.gov (United States)

    Lu, Louise; Sick, Volker

    2013-06-24

    Multi-dimensional and transient flows play a key role in many areas of science, engineering, and health sciences but are often not well understood. The complex nature of these flows may be studied using particle image velocimetry (PIV), a laser-based imaging technique for optically accessible flows. Though many forms of PIV exist that extend the technique beyond the original planar two-component velocity measurement capabilities, the basic PIV system consists of a light source (laser), a camera, tracer particles, and analysis algorithms. The imaging and recording parameters, the light source, and the algorithms are adjusted to optimize the recording for the flow of interest and obtain valid velocity data. Common PIV investigations measure two-component velocities in a plane at a few frames per second. However, recent developments in instrumentation have facilitated high-frame rate (>1 kHz) measurements capable of resolving transient flows with high temporal resolution. Therefore, high-frame rate measurements have enabled investigations on the evolution of the structure and dynamics of highly transient flows. These investigations play a critical role in understanding the fundamental physics of complex flows. A detailed description for performing high-resolution, high-speed planar PIV to study a transient flow near the surface of a flat plate is presented here. Details for adjusting the parameter constraints such as image and recording properties, the laser sheet properties, and processing algorithms to adapt PIV for any flow of interest are included.

  17. 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.

  18. Modal Analysis of High Speed Motorized Spindle for Camshaft Grinder Based on the Finite Element Method%基于有限元方法的高速凸轮轴磨床电主轴的模态分析

    Institute of Scientific and Technical Information of China (English)

    张尚; 柳懿麟; 彭碧; 郑孟昆

    2012-01-01

    利用有限元法分析高速凸轮轴磨床主轴的动态特性,并对前后轴承的刚度和止推轴承的位置进行分析,为类似的液压主轴设计提供依据.%By adoption of the finite element analysis to analyze the dynamic characteristics of the spindle in high-speed camshaft grinding machine and analysis of the location of the thrust bearing and the stiffness of front and rear bearings. It is able to provide theoretical references in design of hydraulic spindles.

  19. 汽车燃料和排放物的快速气相色谱分析%HIGH-SPEED GAS CHROMATOGRAPHY ANALYSIS OF AUTOMOTIVE FUELS AND EXHAUST SPECIES

    Institute of Scientific and Technical Information of China (English)

    AKIYAMAK

    2003-01-01

    The chemical analysis of organic compounds in the automotive fuels and exhaust species is an extremely important and complex procedure. For these compounds analysis, gas chromatography is the most widely method used because of its excellent selectivity, and wide dynamic concentration range. Although, analysis time of automotive fuels and exhausts are very long because these are complex mixtures, and target compounds in these samples are very low concentration. Concentrations of some species for example 13-butadiene are change after collection. Long analysis turnaround time make cost increase. The high-speed gas chromatography analysis techniques of automotive fuels and exhaust species are developed, because to decrease turnaround of analysis time is very important for cutback the cost of experiments and ensure of reliability.

  20. 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.

  1. 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).

  2. 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...

  3. 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.

  4. Analysis of effects factors of high speed signal via on signal%高速信号过孔对信号影响因素研究

    Institute of Scientific and Technical Information of China (English)

    余凯; 胡新星; 刘丰; 华炎生

    2014-01-01

    影响信号完整性的因素有很多,其中过孔结构对信号影响越来越明显,如何进行有效的过孔设计从而使过孔阻抗与激励源阻抗配从而达到信号完整性已经成为当今PCB设计业界中的一个热门课题。文章通过Ansys公司的HFSS仿真软件,利用仿真方法分析不同信号过孔结构对高速信号的影响,并对过孔残桩长度(stub),反焊盘,焊盘的不同大小对信号差损影响程度做了进一步研究。%Many factors can affect SI, and the via structure’s impact is more and more obvious. How to control the via impedance to match the excitation source’s impedance, thus, reduce SI problem. This is a new hot topic in PCB design. In this paper, the inlfuence of different via structure on high-speed signal is analyzed with simulation by ANSYS’s HFSS. Meanwhile we make further study on the inlfuence of remaining stub lengths, the size of anti-pad and pad on signal insertion loss proifle.

  5. Construction management through bot:Taiwan high speed rall case

    Institute of Scientific and Technical Information of China (English)

    CHANG Luh-maan; CHEN Po-han

    2004-01-01

    One of the key elements in real estate management is streamlining the construction process. Thus,the facilities can be built on a faster, cheaper, and higher quality base. Consequently, it will enhance the owner's competitiveness. Due to the high cost and lengthy duration of mega-construction projects in recent years,Build-Operate-Transfer (BOT) contracts are getting popular in delivering constructed projects in the public sector. With BOT, the public owners are able to focus on the effectiveness of fair resource allocation as well as bring the efficiency of private enterprise into governmental operations.This paper uses Taiwan High Speed Rail project to exemplify the BOT method in executing the constructed projects in the chain of real estate management processes. The paper explains the reasons for building HSR and adopting BOT approach.The detail of the HSR project and the feasibility analysis of the project will be presented in this paper. The feasibility analysis comprises the comparisons of different transportation means, the financial analysis, and other benefits from HSR. Finally, conclusions will be drawn.

  6. 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.

  7. High-speed cinematography of gas-metal atomization

    Energy Technology Data Exchange (ETDEWEB)

    Ting, Jason [ALCOA Specialty Metals Division, 100 Technical Drive, Alcoa Center, PA 15069 (United States)]. E-mail: jason.ting@alcoa.com; Connor, Jeffery [Material Science Engineering Department, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Ridder, Stephen [Metallurgical Processing Group, NIST, 100 Bureau Dr. Stop 8556, Gaithersburg, MD 20899 (United States)

    2005-01-15

    A high-speed cinematographic footage of a 304L stainless steel gas atomization, recorded at the National Institute of Standard and Technology (NIST), was analyzed using a discrete Fourier transform (DFT) algorithm. The analysis showed the gas atomization process possesses two prominent frequency ranges of melt oscillation (pulsation). A low-frequency oscillation in the melt flow occurring between 5.41 and 123 Hz, with a dominant frequency at 9.93 Hz, was seen in the recirculation zone adjacent to the melt orifice. A high-frequency melt oscillation range was observed above 123 Hz, and was more prominent one melt-tip-diameter downstream in the melt atomization image than upstream near the melt tip. This high-frequency range may reflect the melt atomization frequency used to produce finely atomized powder. This range also included a prominent high frequency at 1273 Hz, which dominated in the image further away downstream from the melt tip. This discrete high-frequency oscillation is most probably caused by the aeroacoustic ''screech'' phenomenon, intrasound (<20 kHz), a result of the atomizing gas jets undergoing flow resonance. It is hypothesized that this discrete intrinsic aeroacoustic tone may enhance melt breakup in the atomization process with evidence of this fact in the melt images.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Analysis of the Inlfuence of Wear Hefei-Wuhan High-speed Railway Bridge Structure of Shield Interval%盾构区间下穿合武高铁桥涵结构影响分析

    Institute of Scientific and Technical Information of China (English)

    王尚伟

    2016-01-01

    This article is based on interval shield Erqi Road, a project of Wuhan Rail Transit Line 3 ~ Xingye Road Station under wear Wu high speed railway bridge and culvert structure, high-speed rail line design speed of 250km/h, set aside 300Km/h and the above conditions. The FLAC3D and ANSYS finite element calculation software and 3D stratum-structure model of high iron operation process of shield construction simulation calculation were carried out, and according to the results of analysis of shield interval, it proposed technical requirements and suggestions on design and construction..%本文以武汉轨道交通3号线一期工程二七路~兴业路站盾构区间下穿合武高铁桥涵结构为例,利用FLAC3D、ANSYS有限元计算软件,采用三维地层—结构模型对高铁运营过程中的盾构施工进行了模拟计算,并根据分析结果对盾构区间提出设计和施工方面的技术要求和建议。

  13. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

  16. High-speed, high-temperature magnetic bearings for jet turbine engine application

    Energy Technology Data Exchange (ETDEWEB)

    Mekhiche, M.; Nichols, S.; Hevenhill, D.; Oleksy, J.; Young, J.; Kirtley, J.L. [SatCon Technology Corporation, Cambridge, MA (United States)

    2000-08-01

    In order to double today's jet turbine engines' propulsion capability, lightweight, high-efficiency, high-speed and hightemperature components are sought. These requirements put the conventional components such as the mechanical bearings under excessive constraints and make them obsolete. In this context, SatCon Technology Corporation has developed a high-speed, high- temperature (50 krpm, 600 deg. C) magnetic bearing system that has the potential of meeting the requirements described above. This magnetic bearing system, comprised of two radial and one double acting thrust bearings, was successfully tested to 50,000 rpm. This paper describes the development of this system from its design, through its fabrication and final testing. Details on the system and component requirements are presented, along with a step-by step design and trade-off analysis. Test data and their discussion are provided as well. (orig.)

  17. 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...

  18. Numerical analysis of applying special pavements to solve the frost heave diseases of high-speed railway roadbeds in seasonally frozen ground regions

    Institute of Scientific and Technical Information of China (English)

    Chang Yuan; FuJun Niu; QiHao Yu; XinBin Wang; Lei Guo; YanHui You

    2015-01-01

    The Haerbin-Dalian Passenger Dedicated Line is the first high-speed railway constructed in the seasonally frozen ground regions of northeastern China. Frost heave diseases occurred in the first winter of its operation (between October 2012 and January 2013), and frost heave was observed mainly in the roadbed fills that were considered not susceptible to frost heave. This paper proposes applying two special pavements — black pavement and insulation-black pavement — to improve the thermal regime of the roadbed. Three numerical models of the roadbed temperature field were built based on the field con-ditions of the Changchun section (D3K692+840 to D3K692+860). The results show that: (1) Compared with cement pave-ment, black pavement and insulation-black pavement could reduce the freezing index at the roadbed surface by 37% and 64%, respectively, which could influence the maximum frozen depth; (2) the maximum frozen depths under the black pavement and insulation-black pavement were respectively 1.3–1.4 m and 1 m. Compared with cement pavement, they could reduce the maximum frozen depth by 0.4 m and 0.7–0.8 m, respectively, which would reduce the permitted amount of frost heave by 4 mm and 7–8 mm, which would meet the deformation limit established by theCode for Design on Special Subgrade of Railway; (3) the freezing periods of the black pavement and the insulation-black pavement were, respectively, approximately four months and two months. Compared with cement pavement, they could reduce the freezing period by approximately 19 days and 40 days, respectively, and delay the initial freezing time by 9 days and 18 days; and (4) compared with cement pavement, black pavement and black-insulation pavement could reduce the frozen areas of roadbeds in the cold season, which suggests that these two special pavements could provide better thermal stability for roadbeds.

  19. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.

    2014-07-01

    Full Text Available Gears are one of the most widely applied precision machine elements in power transmission systems employed in automotive, aerospace, marine, rail and industrial applications because of their reliability, precision, efficiency and versatility. Fundamentally, gears provide a very practical mechanism to transmit motion and mechanical power between two rotating shafts. However, their performance and accuracy are often hampered by tooth failure, vibrations and whine noise. This is most acute in high-speed, high power density geared rotor systems, which is the primary scope of this paper. The present study focuses on the development of a gear pair mathematical model for use to analyze the dynamics of power transmission systems. The theory includes the gear mesh representation derived from results of the quasi-static tooth contact analysis. This proposed gear mesh theory comprising of transmission error, mesh point, mesh stiffness and line-of-action nonlinear, time-varying parameters can be easily incorporated into a variety of transmission system models ranging from the lumped parameter type to detailed finite element representation. The gear dynamic analysis performed led to the discovery of the out-of-phase gear pair torsion modes that are responsible for much of the mechanical problems seen in gearing applications. The paper concludes with a discussion on effectual design approaches to minimize the influence of gear dynamics and to mitigate gear failure in practical power transmission systems.

  20. 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

  1. Analysis of China’s High-Speed Rail Express Strategy Based on SWOT-AHP%基于 SWOT-A HP 的我国高铁快运战略分析

    Institute of Scientific and Technical Information of China (English)

    孙雅颖

    2015-01-01

    基于当前我国高速铁路的迅速发展及快递业务量的高速增长,对我国高铁快递的发展环境进行SWOT 分析,并运用AHP方法将分析结果进行量化,进而建立SWOT‐AHP模型,对该业务发展战略进行科学定位。模型研究结果显示:高铁快运业务发展应选择机会型开拓战略。文中最后提出对策与建议。%Based on the rapid development and continued grow th of our business volume in the current high‐speed railway ,analysis the development of high speed rail express in SWOT ,and uses the AHP method to quantify the results of the analysis ,then establishes the model in order to carry out scientific orientation of the business development strategy .Model results show :the development of high‐speed railway express business should choose to develop opportunistic strategy . Finally , put forward countermeasures and suggestions .

  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. 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

  4. 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.

  5. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.

    1999-03-01

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

  6. 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.

  7. 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.

  8. 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....

  9. 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,

  10. 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.

  11. 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.

  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. Analysis of motion in speed skating

    Science.gov (United States)

    Koga, Yuzo; Nishimura, Tetsu; Watanabe, Naoki; Okamoto, Kousuke; Wada, Yuhei

    1997-03-01

    A motion on sports has been studied by many researchers from the view of the medical, psychological and mechanical fields. Here, we try to analyze a speed skating motion dynamically for an aim of performing the best record. As an official competition of speed skating is performed on the round rink, the skating motion must be studied on the three phases, that is, starting phase, straight and curved course skating phase. It is indispensable to have a visual data of a skating motion in order to analyze kinematically. So we took a several subject's skating motion by 8 mm video cameras in order to obtain three dimensional data. As the first step, the movement of the center of gravity of skater (abbreviate to C. G.) is discussed in this paper, because a skating motion is very complicated. The movement of C. G. will give an information of the reaction force to a skate blade from the surface of ice. We discuss the discrepancy of several skating motion by studied subjects. Our final goal is to suggest the best skating form for getting the finest record.

  16. 高速动车组速度传感器的电磁干扰测试与分析%Electromagnetic interference measurement and analysis of high-speed electric multiple units speed sensor

    Institute of Scientific and Technical Information of China (English)

    严加斌; 朱峰; 李军; 沙淼; 袁德强

    2015-01-01

    Combining with field measurement, the electromagnetic interference issues of CRH380BL speed sensor is studied.Firstly we analyze Hall switch sensor has good anti-jamming capability itself, and point out that car body overvoltage produced by the arc discharge during the bow down will interfere with it .Then the electric dipole theory is used to analyze the characteristics of the electromagnetic field excited during the bow down .From the point that the tangential component of magnetic field is not continuous in the surface of the medium , the reason of car body over-voltage generate is analyzed.From the perspective of the sensor transmission cable shield grounding method , the coupling mechanism of car body over-voltage interference with sensor is also analyzed.The results show that the maximum value of magnetic field is 54.07 dBμA/m and its frequency is mainly distributed around 5 MHz, the over-voltage of No.2 car body is more than 600V.Car body harassment voltage will couple to core wire by the para-sitic capacitance between cable shield and core wire , then coursing interference to speed signal transmitted in the core wire.Through adding protective grounding on No.1 car, the electromagnetic interference of speed sensor from arc discharge effectively is reduced .%结合现场实测,对CRH380BL型动车组速度传感器的电磁干扰问题进行了研究。首先分析了开关型霍尔传感器自身具有良好的抗干扰能力,指出当降弓时产生的电弧放电在车体上产生过电压时将会对其产生干扰。然后采用电偶极子理论分析了降弓时激发的电磁场的特性,从磁场在介质表面切向分量不连续的角度分析了车体过电压产生的原因,最后从传感器传输电缆屏蔽层接地方式的角度分析了车体过电压对传感器的干扰耦合机理。结果表明:降弓时产生的磁场强度最大值为54.07 dBμA/m,且频率主要分布在5 MHz附近,2号车厢车体过电压达600

  17. 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.

  18. 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.

  19. Software Speeds Up Analysis of Breast Cancer Risk

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161117.html Software Speeds Up Analysis of Breast Cancer Risk: Study ... 22, 2016 THURSDAY, Sept. 22, 2016 (HealthDay News) -- Software that quickly analyzes mammograms and patient history to ...

  20. 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.

  1. 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

  2. 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.

  3. Lagrangian transported MDF methods for compressible high speed flows

    Science.gov (United States)

    Gerlinger, Peter

    2017-06-01

    This paper deals with the application of thermochemical Lagrangian MDF (mass density function) methods for compressible sub- and supersonic RANS (Reynolds Averaged Navier-Stokes) simulations. A new approach to treat molecular transport is presented. This technique on the one hand ensures numerical stability of the particle solver in laminar regions of the flow field (e.g. in the viscous sublayer) and on the other hand takes differential diffusion into account. It is shown in a detailed analysis, that the new method correctly predicts first and second-order moments on the basis of conventional modeling approaches. Moreover, a number of challenges for MDF particle methods in high speed flows is discussed, e.g. high cell aspect ratio grids close to solid walls, wall heat transfer, shock resolution, and problems from statistical noise which may cause artificial shock systems in supersonic flows. A Mach 2 supersonic mixing channel with multiple shock reflection and a model rocket combustor simulation demonstrate the eligibility of this technique to practical applications. Both test cases are simulated successfully for the first time with a hybrid finite-volume (FV)/Lagrangian particle solver (PS).

  4. Composite flywheel material design for high-speed energy storage

    Directory of Open Access Journals (Sweden)

    Michael A. Conteh

    2016-06-01

    Full Text Available Lamina and laminate mechanical properties of materials suitable for flywheel high-speed energy storage were investigated. Low density, low modulus and high strength composite material properties were implemented for the constant stress portion of the flywheel while higher density, higher modulus and strength were implemented for the constant thickness portion of the flywheel. Design and stress analysis were used to determine the maximum energy densities and shape factors for the flywheel. Analytical studies along with the use of the CADEC-online software were used to evaluate the lamina and laminate properties. This study found that a hybrid composite of M46J/epoxy–T1000G/epoxy for the flywheel exhibits a higher energy density when compared to known existing flywheel hybrid composite materials such as boron/epoxy–graphite/epoxy. Results from this study will contribute to further development of the flywheel that has recently re-emerged as a promising application for energy storage due to significant improvements in composite materials and technology.

  5. Strain rate effect in high-speed wire drawing process

    Science.gov (United States)

    He, S.; Van Houtte, P.; Van Bael, A.; Mei, F.; Sarban, A.; Boesman, P.; Galvez, F.; Atienza, J. M.

    2002-05-01

    This paper presents a study on the strain rate effect during high-speed wire drawing process by means of finite element simulation. Based on the quasistatic stresses obtained by normal tensile tests and dynamic stresses at high strain rates by split Hopkinson pressure bar tests, the wire drawing process was simulated for low carbon steel and high carbon steel. The results show that both the deformation process and the final properties of drawn wires are influenced by the strain rate.

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

    Directory of Open Access Journals (Sweden)

    Qizhou Hu

    2014-01-01

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

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

    Science.gov (United States)

    Hu, Qizhou; Zhang, Bing

    2014-01-01

    In order to rationally evaluate the high speed railway operation safety level, the environmental safety evaluation index system of high speed railway should be well established by means of analyzing the impact mechanism of severe weather such as raining, thundering, lightning, earthquake, winding, and snowing. In addition to that, the attribute recognition will be identified to determine the similarity between samples and their corresponding attribute classes on the multidimensional space, which is on the basis of the Mahalanobis distance measurement function in terms of Mahalanobis distance with the characteristics of noncorrelation and nondimensionless influence. On top of the assumption, the high speed railway of China environment safety situation will be well elaborated by the suggested methods. The results from the detailed analysis show that the evaluation is basically matched up with the actual situation and could lay a scientific foundation for the high speed railway operation safety. PMID:25435866

  8. High speed railway environment safety evaluation based on measurement attribute recognition model.

    Science.gov (United States)

    Hu, Qizhou; Gao, Ningbo; Zhang, Bing

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Xu Wang

    2015-01-01

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

  10. High-speed high-sensitivity infrared spectroscopy using mid-infrared swept lasers (Conference Presentation)

    Science.gov (United States)

    Childs, David T. D.; Groom, Kristian M.; Hogg, Richard A.; Revin, Dmitry G.; Cockburn, John W.; Rehman, Ihtesham U.; Matcher, Stephen J.

    2016-03-01

    Infrared spectroscopy is a highly attractive read-out technology for compositional analysis of biomedical specimens because of its unique combination of high molecular sensitivity without the need for exogenous labels. Traditional techniques such as FTIR and Raman have suffered from comparatively low speed and sensitivity however recent innovations are challenging this situation. Direct mid-IR spectroscopy is being speeded up by innovations such as MEMS-based FTIR instruments with very high mirror speeds and supercontinuum sources producing very high sample irradiation levels. Here we explore another possible method - external cavity quantum cascade lasers (EC-QCL's) with high cavity tuning speeds (mid-IR swept lasers). Swept lasers have been heavily developed in the near-infrared where they are used for non-destructive low-coherence imaging (OCT). We adapt these concepts in two ways. Firstly by combining mid-IR quantum cascade gain chips with external cavity designs adapted from OCT we achieve spectral acquisition rates approaching 1 kHz and demonstrate potential to reach 100 kHz. Secondly we show that mid-IR swept lasers share a fundamental sensitivity advantage with near-IR OCT swept lasers. This makes them potentially able to achieve the same spectral SNR as an FTIR instrument in a time x N shorter (N being the number of spectral points) under otherwise matched conditions. This effect is demonstrated using measurements of a PDMS sample. The combination of potentially very high spectral acquisition rates, fundamental SNR advantage and the use of low-cost detector systems could make mid-IR swept lasers a powerful technology for high-throughput biomedical spectroscopy.

  11. Toward high-speed access technologies: results from MUSE

    Science.gov (United States)

    Wellen, Jeroen; Smets, Rob; Hellenthal, Wim; Lepley, Jason; Tsalamanis, Ioannis; Walker, Stuart; Ng'oma, Anthony; Rijckenberg, Gert-Jan; Koonen, Ton; Habel, Kai; Langer, Klaus-Dieter

    2006-10-01

    The European MUSE project, which aims to enable "MUlti Service and access Everywhere", studies architectures, technologies and business scenarios facilitating the deployment of new Broadband Access Networks and Services. This paper gives an overview and particularly discusses results of some of the high-speed access technologies that are developed.

  12. Size Reduction of Tunable Micromachined Filters for High Speed Operations

    Institute of Scientific and Technical Information of China (English)

    Tomoyuki; Hino; Takeru; Amano; Wiganes; Janto; Fumio; Koyama

    2003-01-01

    The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 run and a short cantilever of 45 urn, exhibiting fast response of below 3 us.

  13. Size Reduction of Tunable Micromachined Filters for High Speed Operations

    Institute of Scientific and Technical Information of China (English)

    Tomoyuki Hino; Takeru Amano; Wiganes Janto; Fumio Koyama

    2003-01-01

    The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 nm and a short cantilever of 45 μm, exhibiting fast response of below 3 μs.

  14. APPLICATION OF POWDER HIGH-SPEED STEEL AS ANTIFRICTION MATERIAL

    Directory of Open Access Journals (Sweden)

    M. Beznak

    2011-01-01

    Full Text Available The influence of disulphide molybdenum additives on antifriction characteristics of powder high-speed steel produced by means of hot hydrostatic pressing is investigated. It is shown that disulphide molybdenum additives promote the decrease of coefficient of friction and temperature in hearth of friction as a result the increase of wear resistance of steel.

  15. Modelling Of Residual Stresses Induced By High Speed Milling Process

    Science.gov (United States)

    Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

    2011-05-01

    Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction. Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge® software, is based on data taken from Outeiro & al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature. Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R&D to those given by numerical simulations is achieved.

  16. Minimum Plate Thickness in High-Speed Craft

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    The minimum plate thickness requirements specified by the classification societies for high-speed craft are supposed to ensure adequate resistance to impact loads such as collision with floating objects and objects falling on the deck. The paper presents analytical methods of describing such impact...

  17. Exploring THz band for high speed wireless communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhang, Hangkai; Jia, Shi;

    2016-01-01

    We overview recent trend in developing high speed wireless communication systems by exploring large bandwidth available in the THz band, and we also present our recent experimental achievements on 400 GHz wireless transmission with a data rate of up to 60 Gbit/s by using a uni-travelling carrier...

  18. High Speed Lunar Navigation for Crewed and Remotely Piloted Vehicles

    Science.gov (United States)

    Pedersen, L.; Allan, M.; To, V.; Utz, H.; Wojcikiewicz, W.; Chautems, C.

    2010-01-01

    Increased navigation speed is desirable for lunar rovers, whether autonomous, crewed or remotely operated, but is hampered by the low gravity, high contrast lighting and rough terrain. We describe lidar based navigation system deployed on NASA's K10 autonomous rover and to increase the terrain hazard situational awareness of the Lunar Electric Rover crew.

  19. High-Speed Computer-Controlled Switch-Matrix System

    Science.gov (United States)

    Spisz, E.; Cory, B.; Ho, P.; Hoffman, M.

    1985-01-01

    High-speed computer-controlled switch-matrix system developed for communication satellites. Satellite system controlled by onboard computer and all message-routing functions between uplink and downlink beams handled by newly developed switch-matrix system. Message requires only 2-microsecond interconnect period, repeated every millisecond.

  20. High-Frequency Technical Trading: The Importance of Speed

    NARCIS (Netherlands)

    M.L. Scholtus (Martin); D.J.C. van Dijk (Dick)

    2012-01-01

    textabstractThis paper investigates the importance of speed for technical trading rule performance for three highly liquid ETFs listed on NASDAQ over the period January 6, 2009 up to September 30, 2009. In addition we examine the characteristics of market activity over the day and within subperiods

  1. Intel Legend and CERN would build up high speed Internet

    CERN Multimedia

    2002-01-01

    Intel, Legend and China Education and Research Network jointly announced on the 25th of April that they will be cooperating with each other to build up the new generation high speed internet, over the next three years (1/2 page).

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

    Science.gov (United States)

    2009-12-08

    passenger rail service, while trying to help rail 25 Available at http://www.fomento.es/MFOMWeb/ paginas ...Offers Guideposts for U.S.,” The New York Times On the Web , May 30, 2009. High Speed Rail (HSR) in the United States Congressional Research

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    OpenAIRE

    Shih-Chen Shi; Chieh-Chang Su

    2016-01-01

    The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose phthalate (HPMCP), and hydroxypropyl methylcellulose acetate succinate (HPMCAS) film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate prom...

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

    CSIR Research Space (South Africa)

    Olivier, M

    2013-08-01

    Full Text Available A method to optimise the geometry, explosive charge mass and volume of an argon bomb for specific lighting requirements has been proposed. The method is specifically aimed at applications that require photographic diagnostics with ultra-high speed...

  6. Research and practice: The European High Speed Station

    NARCIS (Netherlands)

    Triggianese, M.

    2014-01-01

    The practices of planning and architecture are undergoing considerable transformation especially for urban developments asso-ciated to infrastructural changes. This paper considers the proliferation of high-speed railways in Europe as a research opportunity to better understand the practice of compl

  7. Towards a high-speed quantum random number generator

    Science.gov (United States)

    Stucki, Damien; Burri, Samuel; Charbon, Edoardo; Chunnilall, Christopher; Meneghetti, Alessio; Regazzoni, Francesco

    2013-10-01

    Randomness is of fundamental importance in various fields, such as cryptography, numerical simulations, or the gaming industry. Quantum physics, which is fundamentally probabilistic, is the best option for a physical random number generator. In this article, we will present the work carried out in various projects in the context of the development of a commercial and certified high speed random number generator.

  8. Modeling of high speed micro rotors in moderate flow confinement

    NARCIS (Netherlands)

    Dikmen, E.; Hoogt, van der P.J.M.; Aarts, R.G.K.M.

    2008-01-01

    The recent developments in high speed micro rotating machinery lead to the need for multiphysical modeling of the rotor and the surrounding medium. In this study, thermal and flow induced effects on rotor dynamics of geometries with moderate flow confinement are studied. The structure is modeled via

  9. Electrically assisted turbocompound systems for high speed direct injection diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Shahed, S.M.; Beatty, D.J. [Allied Signal Turbocharging Systems (United States)

    1999-07-01

    Turbocharged diesel engines are already the most efficiency prime movers. Further fuel economy gains are being realized by down-sizing engines but with compromised response. AlliedSignal's Electrical Turbocompounding system solves this challenge and further improves fuel economy and power density. It provides additional boost at low speeds and transfers excess turbocharger power to the crankshaft at high speeds. Analysis using a typical baseline engine shows that at low speeds, boost is increased by 100 to 407 mbars and torque by 12 to 50%, by supplying 0.5 to 2.0 kW power assist. At high speeds, up to 10kW of power can be recovered from the turbocharger, improving efficiency by 6-10%. Transient response analysis shows that with electrical assist turbochargers can reach full boost within 0.3-0.5 seconds. (author)

  10. Design criteria for light high speed desert air cushion vehicles

    Science.gov (United States)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  11. Study on High-Speed Magnitude Approximation for Complex Vectors

    Institute of Scientific and Technical Information of China (English)

    陈建春; 杨万海; 许少英

    2003-01-01

    High-speed magnitude approximation algorithms for complex vectors are discussed intensively. The performance and the convergence speed of these approximation algorithms are analyzed. For the polygon fitting algorithms, the approximation formula under the least mean square error criterion is derived. For the iterative algorithms, a modified CORDIC (coordinate rotation digital computer) algorithm is developed. This modified CORDIC algorithm is proved to be with a maximum relative error about one half that of the original CORDIC algorithm. Finally, the effects of the finite register length on these algorithms are also concerned, which shows that 9 to 12-bit coefficients are sufficient for practical applications.

  12. Switching speed limitations of high power IGBT modules

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  13. Development of small bore, high speed tapered roller bearing

    Science.gov (United States)

    Morrison, F. R.; Gassel, S. S.; Bovenkerk, R. L.

    1981-01-01

    The performance of four rolling bearing configurations for use on the input pinion shaft of a proposed commercial helicopter transmission was evaluated. The performance characteristics of a high speed tapered roller bearing operating under conditions comparable to those existing at this input pinion shaft were defined. The tapered roller bearing shaft support configuration was developed for the gearbox using commercially available bearing designings. The configuration was optimized and interactive thermomechanically system analyzed. Automotive pinion quality tapered roller bearings were found to be reliable under load and speed conditions in excess of those anticipated in the helicopter transmission. However, it is indicated that the elastohydrodynamic lubricant films are inadequate.

  14. Research of high speed optical switch based on compound semiconductor

    Institute of Scientific and Technical Information of China (English)

    WANG MingHua; QI Wei; YU Hui; JIANG XiaoQing; YANG JianYi

    2009-01-01

    High-speed optical switch and its array are the crucial components of all-optical switching system. This paper presents the analytical model of a total-internal-reflection (TIR) optical switch. By employing the carrier injection effect in GaAs and the GaAs/AlGaAs double heterojunction structure, the X-junction TIR switch and the Mach-Zehnder interference (MZI) switch are demonstrated at 1.55 IJm. The measured results show that the extinction ratio of both switches exceeds 20 dB. The switching speed reaches the scale of 10 ns.

  15. Design of a high speed rotating mechanical shutter

    Energy Technology Data Exchange (ETDEWEB)

    Stowers, I.F.; Merritt, B.T.; McFann, C.B.

    1979-11-06

    A high-speed rotating shutter was designed to operate in a 10/sup -6/ Torr vacuum at the optical focus of a laser spatial filter. The shutter is basically a wheel, with a single 3 x 10-mm slot at the perimeter, which rotates with a peripheral speed of 1 km/s. The motor to drive the rotating wheel is magnetically suspended and synchronously wound. The wheel achieves a 4 ..mu..s opening time and a timing accuracy of better than 0.2 ..mu..s. (MOW)

  16. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

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

    2004-01-01

    Static CMOS design displays benefits such as low power consumption, dominated by dynamic power consumption. In contrast, MOS Current Mode Logic (MCML) displays static rather than dynamic power consumption. High-speed low-power design is one of the many application areas in VLSI that require...... the appropriate domains of performance and power requirements in which MCML presents benefits over standard CMOS. An optimized cell library is designed and implemented in both CMOS and MCML in order to make a comparison with reference to speed and power. Much more time is spent in order to nderstand...

  17. Ultra High-Speed Radio Frequency Switch Based on Photonics.

    Science.gov (United States)

    Ge, Jia; Fok, Mable P

    2015-11-26

    Microwave switches, or Radio Frequency (RF) switches have been intensively used in microwave systems for signal routing. Compared with the fast development of microwave and wireless systems, RF switches have been underdeveloped particularly in terms of switching speed and operating bandwidth. In this paper, we propose a photonics based RF switch that is capable of switching at tens of picoseconds speed, which is hundreds of times faster than any existing RF switch technologies. The high-speed switching property is achieved with the use of a rapidly tunable microwave photonic filter with tens of gigahertz frequency tuning speed, where the tuning mechanism is based on the ultra-fast electro-optics Pockels effect. The RF switch has a wide operation bandwidth of 12 GHz and can go up to 40 GHz, depending on the bandwidth of the modulator used in the scheme. The proposed RF switch can either work as an ON/OFF switch or a two-channel switch, tens of picoseconds switching speed is experimentally observed for both type of switches.

  18. Design the High Speed Kogge-Stone Adder by Using

    Directory of Open Access Journals (Sweden)

    MUX

    2015-08-01

    Full Text Available In this Technical era the high speed and low area of VLSI chip are very- very essential factors. Day by day number of transistors and other active and passive elements are growing on VLSI chip. In Integral part of the processor adders play an important role. In this paper we are using proposed kogge-stone adders for binary addition to reduce the size and increase the efficiency or processors speed. Proposing kogge stone adder provides less components, less path delay and better speed compare to other existing kogge stone adder and other adders. Here we are comparing the kogge stone adders of different-different word size from other adders. The design and experiment can be done by the aid of Xilinx 14.1i Spartan 3 device family.

  19. Speed Ratio Prediction and Performance Analysis of Single Ball Traction Drive for CVT

    Directory of Open Access Journals (Sweden)

    Kunal S. Marathe

    2014-06-01

    Full Text Available Drives are basically used to transmit power and speed from the prime mover to the machine. The power transmission and speed reduction between the prime-mover and the driven machine can be achieved by using conventional drives like Belt drive, Rope drive, Chain drive, Gears, etc. with their numerous advantages and disadvantages. There are many machines and mechanical units that under varying circumstances make it desirable to be able to drive at a barely perceptible speed, an intermediate speed or a high speed. Thus an infinitely variable (step less speed variation in which it is possible to get any desirable speed. Some mechanical, hydraulic, drives serve as such step less drives. However the torque versus speed characteristics of these drives do not match torque at low speeds. Hence the need of a step less or infinitely variable speed drive came into existence. The drive presented by the end of this research work is single ball traction drive for continuously variable transmission systems. Dissertation includes the brief history of existing drives, speed prediction methodology and performance analysis of the drive developed.

  20. Signal waveform design to detect an underwater high-speed small target

    Institute of Scientific and Technical Information of China (English)

    YANG Chonglin; YAO Lan

    2002-01-01

    The problem of sonar signal waveform design to detect a high-speed small target in an underwater environment is discussed. From theoretical analysis, time-frequency hop signal is regarded as the most suitable signal waveform in this application. To get precise target parameter estimation ability, the signal should have high range-Doppler resolution performance.The results of signal analysis show that hop signal with frequency serial coding as Costas array has sharp ambiguity characteristic, so it can be used in an active sonar system to detect a high speed small target. A scheme of frequency coding is also presented.