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The Effects of Feedback Timing when Teaching a New Task to Children with Autism

Description: The purpose of this experiment was to investigate Tosti's proposal about the timing of feedback. The study examined whether it is better to correct immediately after the error occurs or whether it is better to wait until immediately before the next opportunity to respond. In addition, it aimed to determine whether corrections delivered at different times produced different learner affects. Four children with autism were taught to label two sets of pictures under the two different conditions. Results showed that the timing of the feedback yields similar results in regards to number of correct responses and total trial count. However, in regards to time spent in teaching and learner affect, correcting errors before the next opportunity to respond showed to be the more efficient procedure and produced more favorable affect.
Date: December 2016
Creator: Cochrane, Angela
Partner: UNT Libraries

The effect of valve timing upon the performance of a supercharged engine at altitude and an unsupercharged engine at sea level

Description: This investigation was conducted to determine the comparative effects of valve timing on the performance of an unsupercharged engine at sea level and a supercharged engine at altitude. The tests were conducted on the NACA universal test engine. The timing of the four valve events was varied over a wide range; the engine speeds were varied between 1,050 and 1,500 r.p.m.; the compression ratios were varied between 4.35:1 and 7.35:1. The conditions of exhaust pressure and carburetor pressure of a supercharged engine were simulated for altitudes between 0 and 18,000 feet. The results show that optimum valve timing for a supercharged engine at an altitude of 18,000 feet differs slightly from that for an unsupercharged engine at sea level. A small increase in power is obtained by using the optimum timing for 18,000 feet for altitudes above 5,000 feet. The timing of the intake opening and exhaust closing becomes more critical as the compression ratio is increased.
Date: February 4, 1931
Creator: Schey, Oscar W. & Biermann, Arnold E.
Partner: UNT Libraries Government Documents Department

Effect of spark-timing regularity on the knock of engine performance

Description: Tests on a high-speed single-cylinder engine are described. The regularity of the spark timing was varied by driving the timer from different engine shafts. A simple and reasonably accurate method of determining the spark timing is described. The results show that irregular spark timing may cause large errors in tests of the knocking properties of fuels. For the engine tested, it was found that a change of one crankshaft degree in spark restart was equivalent to an 0.85 inch Hg change in allowable inlet pressure.
Date: May 1938
Creator: Biermann, Arnold E.
Partner: UNT Libraries Government Documents Department

Spark-Timing Control Based on Correlation of Maximum-Economy Spark Timing, Flame-Front Travel, and Cylinder Pressure Rise

Description: Note presenting an investigation conducted on a full-scale air-cooled cylinder in order to establish an effective means of maintaining maximum-economy spark timing with varying engine operating conditions. Variable fuel-air ratio runs were conducted in which relations were determined between the spark timing and basic factors in engine operation, flame-front travel, and cylinder pressure rise. An instrument for controlling spark timing was developed that automatically maintained maximum-economy spark timing with varying engine operating conditions.
Date: February 1947
Creator: Cook, Harvey A.; Heinicke, Orville H. & Haynie, William H.
Partner: UNT Libraries Government Documents Department

Spark-Timing Control Based on Correlation of Maximum-Economy Spark Timing, Flame-Front Travel, and Cylinder-Pressure Rise

Description: "An investigation was conducted on a full-scale air-cooled cylinder in order to establish an effective means of maintaining maximum-economy spark timing with varying engine operating conditions. Variable fuel-air-ratio runs were conducted in which relations were determined between the spark travel, and cylinder-pressure rise. An instrument for controlling spark timing was developed that automatically maintained maximum-economy spark timing with varying engine operating conditions" (p. 1).
Date: 1947
Creator: Cook, Harvey A.; Heinicke, Orville H. & Haynie, William H.
Partner: UNT Libraries Government Documents Department

Distributed Timing and Triggering Control System

Description: This document is a slide show type presentation regarding the need and realization of a new control system for work at the Nevada National Security Site. Commercial products that met the need are identified, both hardware and software. Particular emphasis is on the Integrated Signal Programmer.
Date: August 1, 2012
Creator: Bowen, T., Huerta, J. A.
Partner: UNT Libraries Government Documents Department

Method and apparatus for detecting timing errors in a system oscillator

Description: This invention is comprised of a method of detecting timing errors in a system oscillator for an electronic device, such as a power supply, includes the step of comparing a system oscillator signal with a delayed generated signal and generating a signal representative of the timing error when the system oscillator signal is not identical to the delayed signal. An LED indicates to an operator that a timing error has occurred. A hardware circuit implements the above-identified method.
Date: December 31, 1991
Creator: Gliebe, R.J. & Kramer, W.R.
Partner: UNT Libraries Government Documents Department

Main Injector synchronous timing system

Description: The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumen-tation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to com-plete a full turn of the ring by 61 nanoseconds (or more than 3 RF buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Tim-ing System corrects for this phase slip as well as signal propagation time changes due to tem-perature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the RF clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design, and expected performance of the Synchronous Timing System.
Date: March 2, 1999
Creator: Steimel, Willem Blokland and James
Partner: UNT Libraries Government Documents Department

Upgrade of NSLS timing system

Description: We report on the progress of the new NSLS timing system. There are three types of requirements for NSLS timing system: clocks, synchronization and trigger circuits. All ring revolution frequency clocks are generated using ECL and high speed TTL logic. The synchronization circuits allows to fill both storage rings with any bunch pattern. The triggers are generated by using commercially available digital delay generators. The delay unit`s outputs are ultrastable, with a resolution of 5 ps, and are programmed by computer via IEEE 488 interface. The block diagrams, description of all major timing components and the present status are provided in this paper.
Date: May 1, 1995
Creator: Singh, O.; Ramamoorthy, S.; Sheehan, J. & Smith, J.
Partner: UNT Libraries Government Documents Department

Which version of the equity market timing affects capital structure, perceived mispricing or adverse selection?

Description: Baker and Wurgler (2002) define a new theory of capital structure. In this theory capital structure evolves as the cumulative outcome of past attempts to time the equity market. Baker and Wurgler extend market timing theory to long-term capital structure, but their results do not clearly distinguish between the two versions of market timing: perceived mispricing and adverse selection. The main purpose of this dissertation is to empirically identify the relative importance of these two explanations. First, I retest Baker and Wurgler's theory by using insider trading as an alternative to market-to-book ratio to measure equity market timing. I also formally test the adverse selection model of the equity market timing: first by using post-issuance performance, and then by using three measures of adverse selection. The first two measures use estimates of adverse information costs based on the bid and ask prices, and the third measure is based on the close-to-offer returns. Based on received theory, a dynamic adverse selection model implies that higher adverse information costs lead to higher leverage. On the other hand, a naïve adverse selection model implies that negative inside information leads to lower leverage. The results are consistent with the equity market timing theory of capital structure. The results also indicate that a naïve, as opposed to a dynamic, adverse selection model seems to be the best explanation as to why managers time equity issues.
Date: August 2004
Creator: Chazi, Abdelaziz
Partner: UNT Libraries

Demonstration of Femtosecond-Phase Stabilization in 2 km OpticalFiber

Description: Long-term phase drifts of less than a femtosecond per hour have been demonstrated in a 2 km length of single-mode optical fiber, stabilized interferometrically at 1530 nm. Recent improvements include a wide-band phase detector that reduces the possibility of fringe jumping due to fast external perturbations of the fiber and locking of the master CW laser wavelength to an atomic absorption line. Mode-locked lasers may be synchronized using two wavelengths of the comb, multiplexed over one fiber, each wavelength individually interferometrically stabilized.
Date: June 1, 2007
Creator: Staples, J.W.; Wilcox, R. & Byrd, J.M.
Partner: UNT Libraries Government Documents Department

Sub-10ps monolithic and low-power photodetector readout

Description: Recent advances in photon detectors have resulted in high-density imaging arrays that offer many performance and cost advantages. In particular, the excellent transit time spread of certain devices show promise to provide tangible benefits in applications such as Positron Emission Tomography (PET). Meanwhile, high-density, high-performance readout techniques have not kept on pace for exploiting these developments. Photodetector readout for next generation high event rate particle identification and time-resolved PET requires a highly-integrated, low-power, and cost-effective readout technique. We propose fast waveform sampling as a method that meets these criteria and demonstrate that sub-10ps resolution can be obtained for an existing device.
Date: February 20, 2009
Creator: Varner, Gary S. & Ruckman, Larry L.
Partner: UNT Libraries Government Documents Department

Timer modules for radiation detection systems

Description: In developing radiation detection instrumentation at Rocky Flats, a system concept using plug-in modules was planned. Losses of operational time due to maintenance are drastically reduced as a malfunctioning module can be replaced within minutes. Versatility is another advantage of the modular concept and a particular module can be used in many different system designs. A significant cost savings in system development can also be realized. Two of the timers described are housed in two-wide Nuclear Instrumentation Bin (NIM-BIN) modules and a third model in a one-wide NIM-BIN module. The design uses the latest COS/ MOS (complimentary symmetry metal-oxide semiconductor) integrated circuitry, featuring low power, low cost, and high reliability. These modules were developed specifically for radiation detection systems. Model 24370-21 is used in gross alpha detection systems. Model 27213-21 appears in a medical wound- counter system and the third, Model 27213-23, operates in a gamma spectrometer system. These modules can have application in other related systems as well. Operational procedures and servicing are included. (auth)
Date: March 29, 1974
Creator: Martin, B. E.
Partner: UNT Libraries Government Documents Department

Fast timing discriminator

Description: The processing of pulses with very fast risetimes for timing purposes involves many problems because of the large equivalent bandwidths involved. For pulses with risetimes in the 150 ps range (and full widths at half maximum (FWHM) of 400 ps) bandwidths in excess of 1GHz are required. Furthermore, these very narrow pulses with current amplitudes as small as 1 mA carry very small charges (<10/sup -12/ coulomb), therefore, requiring very sensitive trigger circuits. The difficulty increases when timing characteristics in the picosecond range are sought especially when a wide input signal amplitude range causes a time-walk problem. The fast timing discriminator described has a time-walk of approximately +-75 ps over the input signal range from 80 mV to 3V. A schematic of the discriminator is included, and operation and performance are discussed.
Date: July 11, 1977
Creator: Lo, C. C.
Partner: UNT Libraries Government Documents Department

Development of a Universal Networked Timer at NSTX

Description: A new Timing and Synchronization System component, the Universal Networked Timer (UNT), is under development at the National Spherical Torus Experiment (NSTX). The UNT is a second-generation multifunction timing device that emulates the timing functionality and electrical interfaces originally provided by various CAMAC modules. Using Field Programmable Gate Array (FPGA) technology, each of the UNT's eight channels can be dynamically programmed to emulate a specific CAMAC module type. The timer is compatible with the existing NSTX timing and synchronization system and will also support a (future) clock system with extended performance. To assist system designers and collaborators, software will be written to integrate the UNT with EPICS, MDSplus, and LabVIEW. This paper will describe the timing capabilities, hardware design, programming/software support, and the current status of the Universal Networked Timer at NSTX.
Date: September 23, 2005
Creator: Sichta, P.; Dong, J.; Lawson, J. E.; Oliaro, G. & Wertenbaker, J.
Partner: UNT Libraries Government Documents Department

A Dual Triangle Timing Circuit for Improved Performance of 4-Quadrant H-Bridge Switches

Description: Fermilab is in the process of upgrading its Booster Correction Element System to include full field correction element magnets to correct position and chromaticity throughout the booster cycle. This upgrade requires power supplies with maximum outputs of {+-}180V/{+-}65A, with current bandwidths of 5k Hz and with slew rates of min to max current in 1ms. For seamless operation around zero current and voltage, we use continuous switching on both sides of the bridge. Although the straightforward way of coordinating the switching on both sides of the bridge can be accomplished with one triangle timing wave and one voltage reference, we have found that using two triangle waves yields a switching coordination that effectively doubles the frequency of the differential ripple on the load and allows for better filtering of the output ripple.
Date: May 1, 2009
Creator: Krafczyk, G.; Jensen, C.; Pfeffer, H.; Warchol, G. & /Fermilab
Partner: UNT Libraries Government Documents Department

Study of timing properties of multi-pixel-photon-counter's illuminated by 630 nm and 405 nm PiLas laser light

Description: Timing measurements of Multy-Pixel-Photon Counters (MPPC's) at the picosecond level were performed at Fermilab. The core timing resolution of the amplifiers, discriminators and TAC/ADC combination to perform these measurements is approximately 2 picoseconds. The single photoelectron time resolution (SPTR) was measured for the signals coming from the MPPC's. An SPTR of about one hundred picoseconds was obtained for MPPC's illuminated by picosecond laser pulses. The SPTR depends on applied bias voltage and on the wavelength of the light. A simple model is proposed to explain the difference in the SPTR for blue and red light. Finally, requirements for the MPPC's temperature and bias voltage stability to maintain the time resolution are discussed.
Date: April 1, 2009
Creator: Ronzhin, Anatoly; Demarteau, Marcel; Los, Sergey; Ramberg, Erik & /Fermilab
Partner: UNT Libraries Government Documents Department

Analysis of digital timing methods with BaF(sub 2) scintillators

Description: Various digital methods were examined for determining the relative arrival times of pulses from to 5.08 x 2.54 cm BaF{sub 2} scintillators. In this study, pulses from the photomultiplier tubes were digitized by a 1 Gs/s analog to digital converter and post processed with multiple techniques. These techniques include: (1) leading edge discrimination, (2) moment-analysis, (3) constant fraction discrimination, (4) digital constant traction discrimination, (5) triangular pulse shaping with a leading edge linear regression, and (6) pulse-shape fitting. Average timing resolutions of 456 {+-} 8 ps were obtained with constant fraction discrimination, which is slightly higher than the analog average resolution of 419 {+-} 7 ps. This study explores the application of these digital techniques for pulse-timing applications and their potential advantages and limitations.
Date: January 1, 2002
Creator: Nelson, M. A. (Mark A.); Rooney, B. D. (Brian D.); Dinwiddie, D. R. (Derek R.) & Brunson, G. S. (Glenn S.)
Partner: UNT Libraries Government Documents Department

Weighting mean timers for high energy physics electronics

Description: A new family of electronics circuits, weighting mean timer, is presented in this technical memo. Weighting mean timers can be used in high energy physics experiment electronics to implement the \concurrence" condition in hardware trigger stage. Several possible architectures of weighting mean timers have been discussed.
Date: November 1, 1998
Creator: Wu, J.
Partner: UNT Libraries Government Documents Department