Now showing items 3490-3509 of 3624

    • V^2 power converter control with capacitor current ramp compensation 

      Virginia Tech Intellectual Properties, Inc.; Liu, Pei-Hsin; Lee, Fred C.; Yan, Yingyi (United States Patent and Trademark Office, 2017-03-21)
      Operation of a switching power converter having an output capacitor having a small equivalent series resistance (ESR) is stabilized and jitter reduced by sensing capacitor current with gain and combining the resulting ...
    • Vacuum response and gas leak detection in piezoelectrically driven sound-resonance cavity 

      Dong, Shuxiang; Bai, Feiming; Yan, Li; Cao, Hu; Li, Jiefang; Viehland, Dwight D. (AIP Publishing, 2004-05-01)
      It has been found that a piezoelectrically driven sound-resonance cavity (PSRC) is quite sensitive to low-pressure changes: a change from ambient to vacuum (67 Pa) conditions results in a 89degrees phase shift and a -81% ...
    • Validation of Expert System Performance 

      Balci, Osman; Smith, Eric P. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1986), TR-86-37
      Most definitions of an expert system include some reference to the ability of the system to perform at a level close to human expert performance. Yet the validation of expert systems, that is, the testing of systems so as ...
    • Validation of Multivariate Response Simulation Models by Using Hotelling's Two-sample T^2 Test 

      Balci, Osman; Sargent, Robert G. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1981), CS81016-R
      A procedure is developed by using Hotelling's two-sample T^2 test to test the validity of a multivariate response simulation model that represents an observable system. The validity of the simulation model is tested with ...
    • Validation of Multivariate Response Trace-driven Simulation Models 

      Balci, Osman; Sargent, Robert G. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1982), CS82005-R
      A procedure is developed by using Rotelling's one-sample T^2 test to test the validity of a multivariate response trace-driven simulation model that represents an observable system. The vali- dity of the simulation model ...
    • Validation of Underwater Sensor Package Using Feature Based SLAM 

      Cain, Christopher; Leonessa, Alexander (MDPI, 2016-03-17)
      Robotic vehicles working in new, unexplored environments must be able to locate themselves in the environment while constructing a picture of the objects in the environment that could act as obstacles that would prevent ...
    • Validation, Verification, and Testing Techniques Throughout the Life Cycle of a Simulation Study 

      Unknown author (Department of Computer Science, Virginia Polytechnic Institute & State University, 1994-08-01), TR-94-08
      Life cycle validation, verification, and testing (VV&T) is extremely important for the success of a simulation study. This paper surveys current software VV&T techniques and current simulation model VV&T techniques and ...
    • Validity and Repeatability of Single-Sensor Loadsol Insoles during Landing 

      Peebles, Alexander T.; Maguire, Lindsay A.; Renner, Kristen E.; Queen, Robin M. (MDPI, 2018-11-22)
      Clinically feasible methods for quantifying landing kinetics could help identify patients at risk for secondary anterior cruciate ligament injuries. The purpose of this study was to evaluate the validity and between-day ...
    • Variability of User Interaction with Multi-Platform News Feeds 

      Chhatpar, Chandresh; Lambros, Stelios; Pérez-Quiñones, Manuel A. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2004), TR-04-22
      The development of the World Wide Web (WWW) and proliferation of web enabled devices have allowed various news agencies to enrich their traditional method of distribution of news through TV, radio and print with simultaneous ...
    • Variable Volumetric Stiffness Fluid Mount Design 

      Vahdati, Nader; Ahmadian, Mehdi (Hindawi, 2004-01-01)
      Passive fluid mounts are commonly used in the automotive and aerospace applications to isolate the cabin from the engine noise and vibration. Due to manufacturing and material variabilities, no two identical fluid mount ...
    • Variable-Complexity Response Surface Approximations for Wing Structural Weight in HSCT Design 

      Kaufman, Matthew; Balabanov, Vladimir; Burgee, Susan L.; Giunta, Anthony A.; Grossman, Bernard; Haftka, Raphael T.; Mason, William H.; Watson, Layne T. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1996), TR-96-03
      A procedure for generating and using a polynomial approximation to wing bending material weight of a High Speed Civil Transport (HSCT) is presented. Response surface methodology is used to fit a quadratic polynomial to ...
    • A Variant of the Fisher-Morris Garbage Compaction Algorithm 

      Martin, Johannes J. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1980), CS80006-R
      The garbage compactification algorithm described works in linear time and, for the most part, does not require any work space. It combines marking and compactification into a two-step algorithm. The first step marks all ...
    • The Variety of Ways in Which Instructors Implement a Modular Digital Library Curriculum 

      Wildemuth, Barbara M.; Pomerantz, Jeffrey P.; Oh, Sanghee; Yang, Seungwon; Fox, Edward A. (2009-05-14)
      This poster illustrates how information professionals can implement a modular digital library curriculum. It discusses instructors' perspectives on digital library syllabi, assignments, readings, and overall course content. ...
    • Varsity Football Helmet STAR Protocol 

      Tyson, Abigail M.; Rowson, Steven (Virginia Tech, 2018-03-30)
      This document details the protocol used to rate adult football helmets based on concussion risk according to the Virginia Tech Helmet Ratings.
    • Varying Collimation for Dark-Field Extraction 

      Wang, Ge; Cong, Wenxiang; Shen, Haiou; Zou, Yu (Hindawi, 2010-02-16)
      Although x-ray imaging is widely used in biomedical applications, biological soft tissues have small density changes, leading to low contrast resolution for attenuation-based x-ray imaging. Over the past years, x-ray ...
    • Vectorization Experiment on the IBM 3090 Vector Facility 

      Weimar, Joerg Richard (Department of Computer Science, Virginia Polytechnic Institute & State University, 1990), TR-90-14
      A comparison between sequential code and vectorization code for matrix multiplication is made and the possible ways to vectorize matrix multiplication are examined. The result is that vectorization of the correct loop ...
    • Vehicle Dynamics in Currents 

      Woolsey, C. (Virginia Center for Autonomous Systems, 2011)
      Vehicles operating in non-uniform flow fields are subject to forces and moments that are not captured by kinematic motion models. These effects are even greater when the mass of the displaced fluid is commensurate with the ...
    • Vehicle fleet emissions of black carbon, polycyclic aromatic hydrocarbons, and other pollutants measured by a mobile laboratory in Mexico City 

      Jiang, M.; Marr, Linsey C.; Dunlea, E. J.; Herndon, S. C.; Jayne, J. T.; Kolb, C. E.; Knighton, W. B.; Rogers, T. M.; Zavala, M.; Molina, L. T.; Molina, M. J. (Copernicus Publications, 2005-12-01)
      Black carbon ( BC) and polycyclic aromatic hydrocarbons (PAHs) are of concern due to their effects on climate and health. The main goal of this research is to provide the first estimate of emissions of BC and particle-phase ...
    • Vehicular Access Doors under Hurricane Force Wind Pressure: Analysis Methods and a Design Tool 

      Janas, Matthew; Moen, Cristopher Dennis (Virginia Polytechnic Institute and State University, 2011-08-01)
      It is essential that rolling sheet metal access doors in metal buildings, and the door jambs they are attached to, resist high pressures during an extreme wind event. Catastrophic damage to the building and its contents ...
    • Vehicular Access Doors under Hurricane Force Wind Pressure: Experiments to Study Jamb Behavior 

      Gao, Tian; Moen, Cristopher Dennis (Virginia Polytechnic Institute and State University, 2012-03-01)
      In August of 2009, two 10 ft by 10 ft DBCI 5000 vehicular access doors were tested with a simulated hurricane force wind pressure at the DBCI in Douglasville, GA (Gao and Moen 2009). After evaluating the results from this ...