Fast response of mechatronics module for robotic

NASA Astrophysics Data System (ADS)

Bukhanov, S. S.; Gryzlov, A. A.; Tsirkunenko, A. T.

2018-05-01

The synthesis technique, the mathematical model and results of experimental investigation of the control system of the robotic complex mechatronic module are presented in the article. It is shown that in most cases the dynamic system can be approximated by the serial connection of two first-order aperiodic links, while the speed in the torque control loop can reach 200-300 rad/s. The specified speed of the system was achieved due to improved specific weight and dimensions parameters of the electric drive (element of the mechatronic system) made on the basis of a contactless motor. The obtained results indicate the possibility of successful application of the proposed mechatronic module for objects of robotized systems in which the reference signal changes at a frequency not exceeding 50 Hz.

Serial Comparison Processes and Sex Differences in Clerical Speed.

ERIC Educational Resources Information Center

Majeres, Raymond L.

1988-01-01

Three experiments were conducted with 91 male and 91 female university students to assess sex differences in performance on speeded matching tests and theory on same-different judgments. Results are interpreted via the dual-process hypothesis of same-difference judgments with sex differences explained in terms of serial comparison processes rather…

Serial killers with military experience: applying learning theory to serial murder.

PubMed

Castle, Tammy; Hensley, Christopher

2002-08-01

Scholars have endeavored to study the motivation and causality behind serial murder by researching biological, psychological, and sociological variables. Some of these studies have provided support for the relationship between these variables and serial murder. However, the study of serial murder continues to be an exploratory rather than explanatory research topic. This article examines the possible link between serial killers and military service. Citing previous research using social learning theory for the study of murder, this article explores how potential serial killers learn to reinforce violence, aggression, and murder in military boot camps. As with other variables considered in serial killer research, military experience alone cannot account for all cases of serial murder. Future research should continue to examine this possible link.

Radiology: "killer app" for next generation networks?

PubMed

McNeill, Kevin M

2004-03-01

The core principles of digital radiology were well developed by the end of the 1980 s. During the following decade tremendous improvements in computer technology enabled realization of those principles at an affordable cost. In this decade work can focus on highly distributed radiology in the context of the integrated health care enterprise. Over the same period computer networking has evolved from a relatively obscure field used by a small number of researchers across low-speed serial links to a pervasive technology that affects nearly all facets of society. Development directions in network technology will ultimately provide end-to-end data paths with speeds that match or exceed the speeds of data paths within the local network and even within workstations. This article describes key developments in Next Generation Networks, potential obstacles, and scenarios in which digital radiology can become a "killer app" that helps to drive deployment of new network infrastructure.

Beam Instrument Development System

DOE Office of Scientific and Technical Information (OSTI.GOV)

DOOLITTLE, LAWRENCE; HUANG, GANG; DU, QIANG

Beam Instrumentation Development System (BIDS) is a collection of common support libraries and modules developed during a series of Low-Level Radio Frequency (LLRF) control and timing/synchronization projects. BIDS includes a collection of Hardware Description Language (HDL) libraries and software libraries. The BIDS can be used for the development of any FPGA-based system, such as LLRF controllers. HDL code in this library is generic and supports common Digital Signal Processing (DSP) functions, FPGA-specific drivers (high-speed serial link wrappers, clock generation, etc.), ADC/DAC drivers, Ethernet MAC implementation, etc.

A novel ultrasonic phased array inspection system to NDT for offshore platform structures

NASA Astrophysics Data System (ADS)

Wang, Hua; Shan, Baohua; Wang, Xin; Ou, Jinping

2007-01-01

A novel ultrasonic phased array detection system is developed for nondestructive testing (NDT). The purpose of the system is to make acquisition of data in real-time from 64-element ultrasonic phased array transducer, and to enable real- time processing of the acquired data. The system is composed of five main parts: master unit, main board, eight transmit/receive units, a 64-element transducer and an external PC. The system can be used with 64 element transducers, excite 32 elements, receive and sample echo signals form 32 elements simultaneously at 62.5MHz with 8 bit precision. The external PC is used as the user interface showing the real time images and controls overall operation of the system through USB serial link. The use of Universal Serial Bus (USB) improves the transform speed and reduces hardware interface complexity. The program of the system is written in Visual C++.NET and is platform independent.

Spatial attention interacts with serial-order retrieval from verbal working memory.

PubMed

van Dijck, Jean-Philippe; Abrahamse, Elger L; Majerus, Steve; Fias, Wim

2013-09-01

The ability to maintain the serial order of events is recognized as a major function of working memory. Although general models of working memory postulate a close link between working memory and attention, such a link has so far not been proposed specifically for serial-order working memory. The present study provided the first empirical demonstration of a direct link between serial order in verbal working memory and spatial selective attention. We show that the retrieval of later items of a sequence stored in working memory-compared with that of earlier items-produces covert attentional shifts toward the right. This observation suggests the conceptually surprising notion that serial-order working memory, even for nonspatially defined verbal items, draws on spatial attention.

Rats' Anticipation of Current and Future Trial Outcomes in the Ordered RNR/RNN Serial Pattern Task

ERIC Educational Resources Information Center

Cohen, Jerome; Mohamoud, Sirad; Szelest, Izabela; Kani, Tammy

2008-01-01

In the ordered RNR/RNN serial pattern task, rats often reduce their running speeds on trial 2 less within the RNR than within the RNN series. Initially, investigators (Capaldi, 1985; Capaldi et al., 1983) considered this trial 2 differential speed effect evidence for rats' anticipation of inter-trial outcomes within each series. Later findings,…

A comparison of high-speed links, their commercial support and ongoing R&D activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzalez, H.L.; Barsotti, E.; Zimmermann, S.

Technological advances and a demanding market have forced the development of higher bandwidth communication standards for networks, data links and busses. Most of these emerging standards are gathering enough momentum that their widespread availability and lower prices are anticipated. The hardware and software that support the physical media for most of these links is currently available, allowing the user community to implement fairly high-bandwidth data links and networks with commercial components. Also, switches needed to support these networks are available or being developed. The commercial suppose of high-bandwidth data links, networks and switching fabrics provides a powerful base for themore » implementation of high-bandwidth data acquisition systems. A large data acquisition system like the one for the Solenoidal Detector Collaboration (SDC) at the SSC can benefit from links and networks that support an integrated systems engineering approach, for initialization, downloading, diagnostics, monitoring, hardware integration and event data readout. The issue that our current work addresses is the possibility of having a channel/network that satisfies the requirements of an integrated data acquisition system. In this paper we present a brief description of high-speed communication links and protocols that we consider of interest for high energy physic High Performance Parallel Interface (HIPPI). Serial HIPPI, Fibre Channel (FC) and Scalable Coherent Interface (SCI). In addition, the initial work required to implement an SDC-like data acquisition system is described.« less

A comparison of high-speed links, their commercial support and ongoing R D activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzalez, H.L.; Barsotti, E.; Zimmermann, S.

Technological advances and a demanding market have forced the development of higher bandwidth communication standards for networks, data links and busses. Most of these emerging standards are gathering enough momentum that their widespread availability and lower prices are anticipated. The hardware and software that support the physical media for most of these links is currently available, allowing the user community to implement fairly high-bandwidth data links and networks with commercial components. Also, switches needed to support these networks are available or being developed. The commercial suppose of high-bandwidth data links, networks and switching fabrics provides a powerful base for themore » implementation of high-bandwidth data acquisition systems. A large data acquisition system like the one for the Solenoidal Detector Collaboration (SDC) at the SSC can benefit from links and networks that support an integrated systems engineering approach, for initialization, downloading, diagnostics, monitoring, hardware integration and event data readout. The issue that our current work addresses is the possibility of having a channel/network that satisfies the requirements of an integrated data acquisition system. In this paper we present a brief description of high-speed communication links and protocols that we consider of interest for high energy physic High Performance Parallel Interface (HIPPI). Serial HIPPI, Fibre Channel (FC) and Scalable Coherent Interface (SCI). In addition, the initial work required to implement an SDC-like data acquisition system is described.« less

From animal cruelty to serial murder: applying the graduation hypothesis.

PubMed

Wright, Jeremy; Hensley, Christopher

2003-02-01

Although serial murder has been recorded for centuries, limited academic attention has been given to this important topic. Scholars have attempted to examine the causality and motivations behind the rare phenomenon of serial murder. However, scant research exists which delves into the childhood characteristics of serial murderers. Using social learning theory, some of these studies present supporting evidence for a link between childhood animal cruelty and adult aggression toward humans. Based on five case studies of serial murderers, we contribute to the existing literature by exploring the possible link between childhood cruelty toward animals and serial murder with the application of the graduation hypothesis.

Speeded Probed Recall Is Affected by Grouping.

PubMed

Morra, Sergio; Epidendio, Valentina

2015-01-01

Most of the evidence from previous studies on speeded probed recall supported primacy-gradient models of serial order representation. Two experiments investigated the effect of grouping on speeded probed recall. Six-word lists, followed by a number between 1 and 6, were presented for speeded recall of the word in the position indicated by the number. Grouping was manipulated through interstimulus intervals. In both experiments, a significant Position × Grouping interaction was found in RT. It is concluded that the results are not consistent with models of order representation only based on a primacy gradient. Possible alternative representations of serial order are also discussed; a case is made for a holistic order representation.

Comparative study of signalling methods for high-speed backplane transceiver

NASA Astrophysics Data System (ADS)

Wu, Kejun

2017-11-01

A combined analysis of transient simulation and statistical method is proposed for comparative study of signalling methods applied to high-speed backplane transceivers. This method enables fast and accurate signal-to-noise ratio and symbol error rate estimation of a serial link based on a four-dimension design space, including channel characteristics, noise scenarios, equalisation schemes, and signalling methods. The proposed combined analysis method chooses an efficient sampling size for performance evaluation. A comparative study of non-return-to-zero (NRZ), PAM-4, and four-phase shifted sinusoid symbol (PSS-4) using parameterised behaviour-level simulation shows PAM-4 and PSS-4 has substantial advantages over conventional NRZ in most of the cases. A comparison between PAM-4 and PSS-4 shows PAM-4 gets significant bit error rate degradation when noise level is enhanced.

Implementation of a level 1 trigger system using high speed serial (VXS) techniques for the 12GeV high luminosity experimental programs at Thomas Jefferson National Accelerator Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

C. Cuevas, B. Raydo, H. Dong, A. Gupta, F.J. Barbosa, J. Wilson, W.M. Taylor, E. Jastrzembski, D. Abbott

We will demonstrate a hardware and firmware solution for a complete fully pipelined multi-crate trigger system that takes advantage of the elegant high speed VXS serial extensions for VME. This trigger system includes three sections starting with the front end crate trigger processor (CTP), a global Sub-System Processor (SSP) and a Trigger Supervisor that manages the timing, synchronization and front end event readout. Within a front end crate, trigger information is gathered from each 16 Channel, 12 bit Flash ADC module at 4 nS intervals via the VXS backplane, to a Crate Trigger Processor (CTP). Each Crate Trigger Processor receivesmore » these 500 MB/S VXS links from the 16 FADC-250 modules, aligns skewed data inherent of Aurora protocol, and performs real time crate level trigger algorithms. The algorithm results are encoded using a Reed-Solomon technique and transmission of this Level 1 trigger data is sent to the SSP using a multi-fiber link. The multi-fiber link achieves an aggregate trigger data transfer rate to the global trigger at 8 Gb/s. The SSP receives and decodes Reed-Solomon error correcting transmission from each crate, aligns the data, and performs the global level trigger algorithms. The entire trigger system is synchronous and operates at 250 MHz with the Trigger Supervisor managing not only the front end event readout, but also the distribution of the critical timing clocks, synchronization signals, and the global trigger signals to each front end readout crate. These signals are distributed to the front end crates on a separate fiber link and each crate is synchronized using a unique encoding scheme to guarantee that each front end crate is synchronous with a fixed latency, independent of the distance between each crate. The overall trigger signal latency is <3 uS, and the proposed 12GeV experiments at Jefferson Lab require up to 200KHz Level 1 trigger rate.« less

Realization of PLC to the Variable Frequency Speed Regulation System of Mine Local Ventilator based on RS-485 Communication

NASA Astrophysics Data System (ADS)

Ma, Kai; Li, Jian; Yun, Yichong

2018-03-01

The article first introduces the merits of serial communication in the PLC to the variable frequency speed regulation system of mine local ventilator, and then sets up a hardware application development platform of PLC and inverter based on RS-485 communication technology, next presents communication initialization of the PLC and Inverter. Finally according to the control requirements, PLC send run operation & monitoring instruction to Inverter, realizes the serial communication control between the PLC and Inverter.

Integrated test system of infrared and laser data based on USB 3.0

NASA Astrophysics Data System (ADS)

Fu, Hui Quan; Tang, Lin Bo; Zhang, Chao; Zhao, Bao Jun; Li, Mao Wen

2017-07-01

Based on USB3.0, this paper presents the design method of an integrated test system for both infrared image data and laser signal data processing module. The core of the design is FPGA logic control, the design uses dual-chip DDR3 SDRAM to achieve high-speed laser data cache, and receive parallel LVDS image data through serial-to-parallel conversion chip, and it achieves high-speed data communication between the system and host computer through the USB3.0 bus. The experimental results show that the developed PC software realizes the real-time display of 14-bit LVDS original image after 14-to-8 bit conversion and JPEG2000 compressed image after decompression in software, and can realize the real-time display of the acquired laser signal data. The correctness of the test system design is verified, indicating that the interface link is normal.

Baseband processor development for the Advanced Communications Satellite Program

NASA Technical Reports Server (NTRS)

Moat, D.; Sabourin, D.; Stilwell, J.; Mccallister, R.; Borota, M.

1982-01-01

An onboard-baseband-processor concept for a satellite-switched time-division-multiple-access (SS-TDMA) communication system was developed for NASA Lewis Research Center. The baseband processor routes and controls traffic on an individual message basis while providing significant advantages in improved link margins and system flexibility. Key technology developments required to prove the flight readiness of the baseband-processor design are being verified in a baseband-processor proof-of-concept model. These technology developments include serial MSK modems, Clos-type baseband routing switch, a single-chip CMOS maximum-likelihood convolutional decoder, and custom LSL implementation of high-speed, low-power ECL building blocks.

The contribution to immediate serial recall of rehearsal, search speed, access to lexical memory, and phonological coding: an investigation at the construct level.

PubMed

Tehan, Gerald; Fogarty, Gerard; Ryan, Katherine

2004-07-01

Rehearsal speed has traditionally been seen to be the prime determinant of individual differences in memory span. Recent studies, in the main using young children as the participant population, have suggested other contributors to span performance. In the present research, we used structural equation modeling to explore, at the construct level, individual differences in immediate serial recall with respect to rehearsal, search, phonological coding, and speed of access to lexical memory. We replicated standard short-term phenomena; we showed that the variables that influence children's span performance influence adult performance in the same way; and we showed that speed of access to lexical memory and facility with phonological codes appear to be more potent sources of individual differences in immediate memory than is either rehearsal speed or search factors.

A serial digital data communications device. [for real time flight simulation

NASA Technical Reports Server (NTRS)

Fetter, J. L.

1977-01-01

A general purpose computer peripheral device which is used to provide a full-duplex, serial, digital data transmission link between a Xerox Sigma computer and a wide variety of external equipment, including computers, terminals, and special purpose devices is reported. The interface has an extensive set of user defined options to assist the user in establishing the necessary data links. This report describes those options and other features of the serial communications interface and its performance by discussing its application to a particular problem.

SpaceWire: IP, Components, Development Support and Test Equipment

NASA Astrophysics Data System (ADS)

Parkes, S.; McClements, C.; Mills, S.; Martin, I.

SpaceWire is a communications network for use onboard spacecraft. It is designed to connect high data-rate sensors, large solid-state memories, processing units and the downlink telemetry subsystem providing an integrated data-handling network. SpaceWire links are serial, high-speed (2 Mbits/sec to 400 Mbits/sec), bi-directional, full-duplex, pointto- point data links which connect together SpaceWire equipment. Application information is sent along a SpaceWire link in discrete packets. Control and time information can also be sent along SpaceWire links. SpaceWire is defined in the ECSS-E50-12A standard [1]. With the adoption of SpaceWire on many space missions the ready availability of intellectual property (IP) cores, components, software drivers, development support, and test equipment becomes a major issue for those developing satellites and their electronic subsystems. This paper describes the work being done at the University of Dundee and STAR-Dundee Ltd with ESA, BNSC and internal funding to make these essential items available. STAR-Dundee is a spin-out company of the University of Dundee set up specifically to support users of SpaceWire.

Wire like link for cycle reproducible and cycle accurate hardware accelerator

DOEpatents

Asaad, Sameh; Kapur, Mohit; Parker, Benjamin D

2015-04-07

First and second field programmable gate arrays are provided which implement first and second blocks of a circuit design to be simulated. The field programmable gate arrays are operated at a first clock frequency and a wire like link is provided to send a plurality of signals between them. The wire like link includes a serializer, on the first field programmable gate array, to serialize the plurality of signals; a deserializer on the second field programmable gate array, to deserialize the plurality of signals; and a connection between the serializer and the deserializer. The serializer and the deserializer are operated at a second clock frequency, greater than the first clock frequency, and the second clock frequency is selected such that latency of transmission and reception of the plurality of signals is less than the period corresponding to the first clock frequency.

A novel architecture of recovered data comparison for high speed clock and data recovery

NASA Astrophysics Data System (ADS)

Gao, Susan; Li, Fei; Wang, Zhigong; Cui, Hongliang

2005-05-01

A clock and data recovery (CDR) circuit is one of the crucial blocks in high-speed serial link communication systems. The data received in these systems are asynchronous and noisy, requiring that a clock be extracted to allow synchronous operations. Furthermore, the data must be "retimed" so that the jitter accumulated during transmission is removed. This paper presents a novel architecture of CDR, which is very tolerant to long sequences of serial ones or zeros and also robust to occasional long absence of transitions. The design is based on the fact that a basic clock recovery having a clock recovery circuit (CRC) and a data decision circuit separately would generate a high jitter clock when the received non-return-to-zero (NRZ) data with long sequences of ones or zeros. To eliminate this drawback, the proposed architecture incorporates a data circuit decision circuit within the phase-locked loop (PLL) CRC. Other than this, a new phase detector (PD) is also proposed, which was easy to accomplish and robust at high speed. This PD is functional with a random input and automatically turns to disable during both the locked state and long absence of transitions. The voltage-controlled oscillator (VCO) is also designed delicately to suppress the jitter. Due to the high stability, the jitter is highly reduced when the loop is locked. The simulation results of such CDR working at 1.25Gb/s particularly for 1000BASE-X Gigabit Ethernet by using TSMC 0.25μm technology are presented to prove the feasibility of this architecture. One more CDR based on edge detection architecture is also built in the circuit for performance comparisons.

Word Reading Fluency as a Serial Naming Task

ERIC Educational Resources Information Center

Protopapas, Athanassios; Katopodi, Katerina; Altani, Angeliki; Georgiou, George K.

2018-01-01

Word list reading fluency is theoretically expected to depend on single word reading speed. Yet the correlation between the two diminishes with increasing fluency, while fluency remains strongly correlated to serial digit naming. We hypothesized that multi-element sequence processing is an important component of fluency. We used confirmatory…

The Speed of Serial Attention Shifts in Visual Search: Evidence from the N2pc Component.

PubMed

Grubert, Anna; Eimer, Martin

2016-02-01

Finding target objects among distractors in visual search display is often assumed to be based on sequential movements of attention between different objects. However, the speed of such serial attention shifts is still under dispute. We employed a search task that encouraged the successive allocation of attention to two target objects in the same search display and measured N2pc components to determine how fast attention moved between these objects. Each display contained one digit in a known color (fixed-color target) and another digit whose color changed unpredictably across trials (variable-color target) together with two gray distractor digits. Participants' task was to find the fixed-color digit and compare its numerical value with that of the variable-color digit. N2pc components to fixed-color targets preceded N2pc components to variable-color digits, demonstrating that these two targets were indeed selected in a fixed serial order. The N2pc to variable-color digits emerged approximately 60 msec after the N2pc to fixed-color digits, which shows that attention can be reallocated very rapidly between different target objects in the visual field. When search display durations were increased, thereby relaxing the temporal demands on serial selection, the two N2pc components to fixed-color and variable-color targets were elicited within 90 msec of each other. Results demonstrate that sequential shifts of attention between different target locations can operate very rapidly at speeds that are in line with the assumptions of serial selection models of visual search.

High-rate serial interconnections for embedded and distributed systems with power and resource constraints

NASA Astrophysics Data System (ADS)

Sheynin, Yuriy; Shutenko, Felix; Suvorova, Elena; Yablokov, Evgenej

2008-04-01

High rate interconnections are important subsystems in modern data processing and control systems of many classes. They are especially important in prospective embedded and on-board systems that used to be multicomponent systems with parallel or distributed architecture, [1]. Modular architecture systems of previous generations were based on parallel busses that were widely used and standardised: VME, PCI, CompactPCI, etc. Busses evolution went in improvement of bus protocol efficiency (burst transactions, split transactions, etc.) and increasing operation frequencies. However, due to multi-drop bus nature and multi-wire skew problems the parallel bussing speedup became more and more limited. For embedded and on-board systems additional reason for this trend was in weight, size and power constraints of an interconnection and its components. Parallel interfaces have become technologically more challenging as their respective clock frequencies have increased to keep pace with the bandwidth requirements of their attached storage devices. Since each interface uses a data clock to gate and validate the parallel data (which is normally 8 bits or 16 bits wide), the clock frequency need only be equivalent to the byte rate or word rate being transmitted. In other words, for a given transmission frequency, the wider the data bus, the slower the clock. As the clock frequency increases, more high frequency energy is available in each of the data lines, and a portion of this energy is dissipated in radiation. Each data line not only transmits this energy but also receives some from its neighbours. This form of mutual interference is commonly called "cross-talk," and the signal distortion it produces can become another major contributor to loss of data integrity unless compensated by appropriate cable designs. Other transmission problems such as frequency-dependent attenuation and signal reflections, while also applicable to serial interfaces, are more troublesome in parallel interfaces due to the number of additional cable conductors involved. In order to compensate for these drawbacks, higher quality cables, shorter cable runs and fewer devices on the bus have been the norm. Finally, the physical bulk of the parallel cables makes them more difficult to route inside an enclosure, hinders cooling airflow and is incompatible with the trend toward smaller form-factor devices. Parallel busses worked in systems during the past 20 years, but the accumulated problems dictate the need for change and the technology is available to spur the transition. The general trend in high-rate interconnections turned from parallel bussing to scalable interconnections with a network architecture and high-rate point-to-point links. Analysis showed that data links with serial information transfer could achieve higher throughput and efficiency and it was confirmed in various research and practical design. Serial interfaces offer an improvement over older parallel interfaces: better performance, better scalability, and also better reliability as the parallel interfaces are at their limits of speed with reliable data transfers and others. The trend was implemented in major standards' families evolution: e.g. from PCI/PCI-X parallel bussing to PCIExpress interconnection architecture with serial lines, from CompactPCI parallel bus to ATCA (Advanced Telecommunications Architecture) specification with serial links and network topologies of an interconnection, etc. In the article we consider a general set of characteristics and features of serial interconnections, give a brief overview of serial interconnections specifications. In more details we present the SpaceWire interconnection technology. Have been developed for space on-board systems applications the SpaceWire has important features and characteristics that make it a prospective interconnection for wide range of embedded systems.

A minimal SATA III Host Controller based on FPGA

NASA Astrophysics Data System (ADS)

Liu, Hailiang

2018-03-01

SATA (Serial Advanced Technology Attachment) is an advanced serial bus which has a outstanding performance in transmitting high speed real-time data applied in Personal Computers, Financial Industry, astronautics and aeronautics, etc. In this express, a minimal SATA III Host Controller based on Xilinx Kintex 7 serial FPGA is designed and implemented. Compared to the state-of-art, registers utilization are reduced 25.3% and LUTs utilization are reduced 65.9%. According to the experimental results, the controller works precisely and steady with the reading bandwidth of up to 536 MB per second and the writing bandwidth of up to 512 MB per second, both of which are close to the maximum bandwidth of the SSD(Solid State Disk) device. The host controller is very suitable for high speed data transmission and mass data storage.

Fast Grasp Contact Computation for a Serial Robot

NASA Technical Reports Server (NTRS)

Hargrave, Brian (Inventor); Shi, Jianying (Inventor); Diftler, Myron A. (Inventor)

2015-01-01

A system includes a controller and a serial robot having links that are interconnected by a joint, wherein the robot can grasp a three-dimensional (3D) object in response to a commanded grasp pose. The controller receives input information, including the commanded grasp pose, a first set of information describing the kinematics of the robot, and a second set of information describing the position of the object to be grasped. The controller also calculates, in a two-dimensional (2D) plane, a set of contact points between the serial robot and a surface of the 3D object needed for the serial robot to achieve the commanded grasp pose. A required joint angle is then calculated in the 2D plane between the pair of links using the set of contact points. A control action is then executed with respect to the motion of the serial robot using the required joint angle.

Apparatus and Method for Effecting Data Transfer Between Data Systems

NASA Technical Reports Server (NTRS)

Kirkpatrick, Joey V. (Inventor); Grosz, Francis B., Jr. (Inventor); Lannes, Kenny (Inventor); Maniscalco, David G. (Inventor)

2001-01-01

An apparatus for effecting data transfer between data systems comprising a first transceiver and a second transceiver. The first transceiver has an input for receiving digital data from one of the data systems, an output for serially outputting digital data to one of the data systems, at least one transmitter for converting digital data received at the input into optical signals, and at least one receiver for receiving optical signals and serially converting the received optical signals to digital data for output to the data output. The second transceiver has an input for receiving digital data from another one of the data systems, an output for serially outputting digital data to the another one of the data systems, at least one transmitter for serially converting digital data received at the input of the second transceiver into optical signals, and at least one receiver for receiving optical signals and serially converting the received optical signals to digital data for output to the output of the second transceiver. The apparatus further comprises an optical link connecting the first and second transceivers. The optical link comprising a pair of optical fibers. One of the optical fibers optically links the transmitter of the first transceiver to the receiver of the second transceiver. The other optical fiber optically links the receiver of the first transceiver to the transmitter of the second transceiver.

The Effect of Cognitive-Task Type and Walking Speed on Dual-Task Gait in Healthy Adults.

PubMed

Wrightson, James G; Ross, Emma Z; Smeeton, Nicholas J

2016-01-01

In a number of studies in which a dual-task gait paradigm was used, researchers reported a relationship between cognitive function and gait. However, it is not clear to what extent these effects are dependent on the type of cognitive and walking tasks used in the dual-task paradigm. This study examined whether stride-time variability (STV) and trunk range of motion (RoM) are affected by the type of cognitive task and walking speed used during dual-task gait. Participants walked at both their preferred walking speed and at 25% of their preferred walking speed and performed a serial subtraction and a working memory task at both speeds. Although both tasks significantly reduced STV at both walking speeds, there was no difference between the two tasks. Trunk RoM was affected by the walking speed and type of cognitive task used during dual-task gait: Mediolateral trunk RoM was increased at the slow walking speed, and anterior-posterior trunk RoM was higher only when performing the serial subtraction task at the slow walking speed. The reduction of STV, regardless of cognitive-task type, suggests that healthy adults may redirect cognitive processes away from gait toward cognitive-task performance during dual-task gait.

[Registration and 3D rendering of serial tissue section images].

PubMed

Liu, Zhexing; Jiang, Guiping; Dong, Wu; Zhang, Yu; Xie, Xiaomian; Hao, Liwei; Wang, Zhiyuan; Li, Shuxiang

2002-12-01

It is an important morphological research method to reconstruct the 3D imaging from serial section tissue images. Registration of serial images is a key step to 3D reconstruction. Firstly, an introduction to the segmentation-counting registration algorithm is presented, which is based on the joint histogram. After thresholding of the two images to be registered, the criterion function is defined as counting in a specific region of the joint histogram, which greatly speeds up the alignment process. Then, the method is used to conduct the serial tissue image matching task, and lies a solid foundation for 3D rendering. Finally, preliminary surface rendering results are presented.

Parallel processing data network of master and slave transputers controlled by a serial control network

DOEpatents

Crosetto, D.B.

1996-12-31

The present device provides for a dynamically configurable communication network having a multi-processor parallel processing system having a serial communication network and a high speed parallel communication network. The serial communication network is used to disseminate commands from a master processor to a plurality of slave processors to effect communication protocol, to control transmission of high density data among nodes and to monitor each slave processor`s status. The high speed parallel processing network is used to effect the transmission of high density data among nodes in the parallel processing system. Each node comprises a transputer, a digital signal processor, a parallel transfer controller, and two three-port memory devices. A communication switch within each node connects it to a fast parallel hardware channel through which all high density data arrives or leaves the node. 6 figs.

High-speed fixed-target serial virus crystallography

DOE PAGES

Roedig, Philip; Ginn, Helen M.; Pakendorf, Tim; ...

2017-06-19

Here, we report a method for serial X-ray crystallography at X-ray free-electron lasers (XFELs), which allows for full use of the current 120-Hz repetition rate of the Linear Coherent Light Source (LCLS). Using a micropatterned silicon chip in combination with the high-speed Roadrunner goniometer for sample delivery, we were able to determine the crystal structures of the picornavirus bovine enterovirus 2 (BEV2) and the cytoplasmic polyhedrosis virus type 18 polyhedrin, with total data collection times of less than 14 and 10 min, respectively. Our method requires only micrograms of sample and should therefore broaden the applicability of serial femtosecond crystallographymore » to challenging projects for which only limited sample amounts are available. By synchronizing the sample exchange to the XFEL repetition rate, our method allows for most efficient use of the limited beam time available at XFELs and should enable a substantial increase in sample throughput at these facilities.« less

High-speed fixed-target serial virus crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roedig, Philip; Ginn, Helen M.; Pakendorf, Tim

Here, we report a method for serial X-ray crystallography at X-ray free-electron lasers (XFELs), which allows for full use of the current 120-Hz repetition rate of the Linear Coherent Light Source (LCLS). Using a micropatterned silicon chip in combination with the high-speed Roadrunner goniometer for sample delivery, we were able to determine the crystal structures of the picornavirus bovine enterovirus 2 (BEV2) and the cytoplasmic polyhedrosis virus type 18 polyhedrin, with total data collection times of less than 14 and 10 min, respectively. Our method requires only micrograms of sample and should therefore broaden the applicability of serial femtosecond crystallographymore » to challenging projects for which only limited sample amounts are available. By synchronizing the sample exchange to the XFEL repetition rate, our method allows for most efficient use of the limited beam time available at XFELs and should enable a substantial increase in sample throughput at these facilities.« less

Parallel processing data network of master and slave transputers controlled by a serial control network

DOEpatents

Crosetto, Dario B.

1996-01-01

The present device provides for a dynamically configurable communication network having a multi-processor parallel processing system having a serial communication network and a high speed parallel communication network. The serial communication network is used to disseminate commands from a master processor (100) to a plurality of slave processors (200) to effect communication protocol, to control transmission of high density data among nodes and to monitor each slave processor's status. The high speed parallel processing network is used to effect the transmission of high density data among nodes in the parallel processing system. Each node comprises a transputer (104), a digital signal processor (114), a parallel transfer controller (106), and two three-port memory devices. A communication switch (108) within each node (100) connects it to a fast parallel hardware channel (70) through which all high density data arrives or leaves the node.

High-speed fixed-target serial virus crystallography

PubMed Central

Roedig, Philip; Ginn, Helen M.; Pakendorf, Tim; Sutton, Geoff; Harlos, Karl; Walter, Thomas S.; Meyer, Jan; Fischer, Pontus; Duman, Ramona; Vartiainen, Ismo; Reime, Bernd; Warmer, Martin; Brewster, Aaron S.; Young, Iris D.; Michels-Clark, Tara; Sauter, Nicholas K.; Kotecha, Abhay; Kelly, James; Rowlands, David J.; Sikorsky, Marcin; Nelson, Silke; Damiani, Daniel S.; Alonso-Mori, Roberto; Ren, Jingshan; Fry, Elizabeth E.; David, Christian; Stuart, David I.; Wagner, Armin; Meents, Alke

2017-01-01

We report a method for serial X-ray crystallography at X-ray free electron lasers (XFELs), which allows for full use of the current 120 Hz repetition rate of the Linear Coherent Light Source (LCLS). Using a micro-patterned silicon chip in combination with the high-speed Roadrunner goniometer for sample delivery we were able to determine the crystal structures of a picornavirus, bovine enterovirus 2 (BEV2), and the cytoplasmic polyhedrosis virus type 18 polyhedrin. Total data collection times were less than 14 and 10 minutes, respectively. Our method requires only micrograms of sample and will therefore broaden the applicability of serial femtosecond crystallography to challenging projects for which only limited sample amounts are available. By synchronizing the sample exchange to the XFEL repetition rate, our method allows for the most efficient use of the limited beamtime available at XFELs and should enable a substantial increase in sample throughput at these facilities. PMID:28628129

High-performance dual-speed CCD camera system for scientific imaging

NASA Astrophysics Data System (ADS)

Simpson, Raymond W.

1996-03-01

Traditionally, scientific camera systems were partitioned with a `camera head' containing the CCD and its support circuitry and a camera controller, which provided analog to digital conversion, timing, control, computer interfacing, and power. A new, unitized high performance scientific CCD camera with dual speed readout at 1 X 106 or 5 X 106 pixels per second, 12 bit digital gray scale, high performance thermoelectric cooling, and built in composite video output is described. This camera provides all digital, analog, and cooling functions in a single compact unit. The new system incorporates the A/C converter, timing, control and computer interfacing in the camera, with the power supply remaining a separate remote unit. A 100 Mbyte/second serial link transfers data over copper or fiber media to a variety of host computers, including Sun, SGI, SCSI, PCI, EISA, and Apple Macintosh. Having all the digital and analog functions in the camera made it possible to modify this system for the Woods Hole Oceanographic Institution for use on a remote controlled submersible vehicle. The oceanographic version achieves 16 bit dynamic range at 1.5 X 105 pixels/second, can be operated at depths of 3 kilometers, and transfers data to the surface via a real time fiber optic link.

Linking Associative and Serial List Memory: Pairs Versus Triples

ERIC Educational Resources Information Center

Caplan, Jeremy B.; Glaholt, Mackenzie G.; McIntosh, Anthony R.

2006-01-01

Paired associates and serial list memory are typically investigated separately. An "isolation principle" (J. B. Caplan, 2005) was proposed to explain behavior in both paradigms by using a single model, in which serial list and paired associates memory differ only in how isolated pairs of items are from interference from other studied items. In…

Verbal Working Memory in Older Adults: The Roles of Phonological Capacities and Processing Speed

ERIC Educational Resources Information Center

Nittrouer, Susan; Lowenstein, Joanna H.; Wucinich, Taylor; Moberly, Aaron C.

2016-01-01

Purpose: This study examined the potential roles of phonological sensitivity and processing speed in age-related declines of verbal working memory. Method: Twenty younger and 25 older adults with age-normal hearing participated. Two measures of verbal working memory were collected: digit span and serial recall of words. Processing speed was…

ATCA/muTCA for Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jezynski, Tomasz; /DESY; Larsen, Raymond

ATCA/{mu}TCA platforms are attractive because of the modern serial link architecture, high availability features and many packaging options. Less-demanding availability applications can be met economically by scaling back speed and redundancy. The ATCA specification was originally targeted for the Telecom industry but has gained recently a much wider user audience. The purpose of this paper is to report on present hardware and software R and D efforts where ATCA and {mu}TCA are planned, already being used or in development using selected examples for accelerator and detectors in the Physics community. It will present also the status of a proposal formore » physics extensions to ATCA/{mu}TCA specifications to promote inter-operability of laboratory and industry designs for physics.« less

RC64, a Rad-Hard Many-Core High- Performance DSP for Space Applications

NASA Astrophysics Data System (ADS)

Ginosar, Ran; Aviely, Peleg; Gellis, Hagay; Liran, Tuvia; Israeli, Tsvika; Nesher, Roy; Lange, Fredy; Dobkin, Reuven; Meirov, Henri; Reznik, Dror

2015-09-01

RC64, a novel rad-hard 64-core signal processing chip targets DSP performance of 75 GMACs (16bit), 150 GOPS and 38 single precision GFLOPS while dissipating less than 10 Watts. RC64 integrates advanced DSP cores with a multi-bank shared memory and a hardware scheduler, also supporting DDR2/3 memory and twelve 3.125 Gbps full duplex high speed serial links using SpaceFibre and other protocols. The programming model employs sequential fine-grain tasks and a separate task map to define task dependencies. RC64 is implemented as a 300 MHz integrated circuit on a 65nm CMOS technology, assembled in hermetically sealed ceramic CCGA624 package and qualified to the highest space standards.

RC64, a Rad-Hard Many-Core High-Performance DSP for Space Applications

NASA Astrophysics Data System (ADS)

Ginosar, Ran; Aviely, Peleg; Liran, Tuvia; Alon, Dov; Mandler, Alberto; Lange, Fredy; Dobkin, Reuven; Goldberg, Miki

2014-08-01

RC64, a novel rad-hard 64-core signal processing chip targets DSP performance of 75 GMACs (16bit), 150 GOPS and 20 single precision GFLOPS while dissipating less than 10 Watts. RC64 integrates advanced DSP cores with a multi-bank shared memory and a hardware scheduler, also supporting DDR2/3 memory and twelve 2.5 Gbps full duplex high speed serial links using SpaceFibre and other protocols. The programming model employs sequential fine-grain tasks and a separate task map to define task dependencies. RC64 is implemented as a 300 MHz integrated circuit on a 65nm CMOS technology, assembled in hermetically sealed ceramic CCGA624 package and qualified to the highest space standards.

Classifying serial killers.

PubMed

Promish, D I; Lester, D

1999-11-08

We attempted to match the appearance and demeanor of 27 serial killers to the postmortem 'signatures' found on their victims' bodies. Our results suggest that a link may exist between postmortem signatures and two complementary appearance-demeanor types.

The Operational Use of an Automated High Frequency Radio System Incorporating Automatic Link Establishment and Single-Tone Serial Modem Technology for U.S. Navy Ship-Shore Communications

DTIC Science & Technology

1993-10-01

between the link chronologically in the following sections. quality analysis ( LQA ) score measured by ALE and single- tone serial modem performance. A...receiving ends in turn and (propagation permitting), pass traffic and terminate the are used to calculate a combined link quality analysis ( LQA ...score. The LQA score is displayed to the operator NCCOSC RDTE DIV installation team accomplished the as a number on an arbitrary scale of 0 to 120, with a

Time does not cause forgetting in short-term serial recall.

PubMed

Lewandowsky, Stephan; Duncan, Matthew; Brown, Gordon D A

2004-10-01

Time-based theories expect memory performance to decline as the delay between study and recall of an item increases. The assumption of time-based forgetting, central to many models of serial recall, underpins their key behaviors. Here we compare the predictions of time-based and event-based models by simulation and test them in two experiments using a novel manipulation of the delay between study and retrieval. Participants were trained, via corrective feedback, to recall at different speeds, thus varying total recall time from 6 to 10 sec. In the first experiment, participants used the keyboard to enter their responses but had to repeat a word (called the suppressor) aloud during recall to prevent rehearsal. In the second experiment, articulation was again required, but recall was verbal and was paced by the number of repetitions of the suppressor in between retrieval of items. In both experiments, serial position curves for all retrieval speeds overlapped, and output time had little or no effect. Comparative evaluation of a time-based and an event-based model confirmed that these results present a particular challenge to time-based approaches. We conclude that output interference, rather than output time, is critical in serial recall.

Decoupling Identification for Serial Two-Link Two-Inertia System

NASA Astrophysics Data System (ADS)

Oaki, Junji; Adachi, Shuichi

The purpose of our study is to develop a precise model by applying the technique of system identification for the model-based control of a nonlinear robot arm, under taking joint-elasticity into consideration. We previously proposed a systematic identification method, called “decoupling identification,” for a “SCARA-type” planar two-link robot arm with elastic joints caused by the Harmonic-drive® reduction gears. The proposed method serves as an extension of the conventional rigid-joint-model-based identification. The robot arm is treated as a serial two-link two-inertia system with nonlinearity. The decoupling identification method using link-accelerometer signals enables the serial two-link two-inertia system to be divided into two linear one-link two-inertia systems. The MATLAB®'s commands for state-space model estimation are utilized in the proposed method. Physical parameters such as motor inertias, link inertias, joint-friction coefficients, and joint-spring coefficients are estimated through the identified one-link two-inertia systems using a gray-box approach. This paper describes accuracy evaluations using the two-link arm for the decoupling identification method under introducing closed-loop-controlled elements and varying amplitude-setup of identification-input. Experimental results show that the identification method also works with closed-loop-controlled elements. Therefore, the identification method is applicable to a “PUMA-type” vertical robot arm under gravity.

Working memory capacity and controlled serial memory search.

PubMed

Mızrak, Eda; Öztekin, Ilke

2016-08-01

The speed-accuracy trade-off (SAT) procedure was used to investigate the relationship between working memory capacity (WMC) and the dynamics of temporal order memory retrieval. High- and low-span participants (HSs, LSs) studied sequentially presented five-item lists, followed by two probes from the study list. Participants indicated the more recent probe. Overall, accuracy was higher for HSs compared to LSs. Crucially, in contrast to previous investigations that observed no impact of WMC on speed of access to item information in memory (e.g., Öztekin & McElree, 2010), recovery of temporal order memory was slower for LSs. While accessing an item's representation in memory can be direct, recovery of relational information such as temporal order information requires a more controlled serial memory search. Collectively, these data indicate that WMC effects are particularly prominent during high demands of cognitive control, such as serial search operations necessary to access temporal order information from memory. Copyright © 2016 Elsevier B.V. All rights reserved.

Information transfer rate with serial and simultaneous visual display formats

NASA Astrophysics Data System (ADS)

Matin, Ethel; Boff, Kenneth R.

1988-04-01

Information communication rate for a conventional display with three spatially separated windows was compared with rate for a serial display in which data frames were presented sequentially in one window. For both methods, each frame contained a randomly selected digit with various amounts of additional display 'clutter.' Subjects recalled the digits in a prescribed order. Large rate differences were found, with faster serial communication for all levels of the clutter factors. However, the rate difference was most pronounced for highly cluttered displays. An explanation for the latter effect in terms of visual masking in the retinal periphery was supported by the results of a second experiment. The working hypothesis that serial displays can speed information transfer for automatic but not for controlled processing is discussed.

Integrated tests of a high speed VXS switch card and 250 MSPS flash ADCs

DOE Office of Scientific and Technical Information (OSTI.GOV)

H. Dong, C. Cuevas, D. Curry, E. Jastrzembski, F. Barbosa, J. Wilson, M. Taylor, B. Raydo

2008-01-01

High trigger rate nuclear physics experiments proposed for the 12 GeV upgrade at the Thomas Jefferson National Accelerator Facility create a need for new high speed digital systems for energy summing. Signals from electronic detectors will be captured with the Jefferson Lab FADC module, which collects and processes data from 16 charged particle sensors with 10 or 12 bit resolution at 250 MHz sample rate. Up to sixteen FADC modules transfer energy information to a central energy summing module for each readout crate. The sums from the crates are combined to form a global energy sum that is used tomore » trigger data readout for all modules. The Energy Sum module and FADC modules have been designed using the VITA-41 VME64 switched serial (VXS) standard. The VITA- 41 standard defines payload and switch slot module functions, and offers an elegant engineered solution for Multi-Gigabit serial transmission on a standard VITA-41 backplane. The Jefferson Lab Energy Sum module receives data serially at a rate of up to 6 Giga-bits per second from the FADC modules. Both FADC and Energy Sum modules have been designed and assembled and this paper describes the integrated tests using both high speed modules in unison« less

The front-end data conversion and readout electronics for the CMS ECAL upgrade

NASA Astrophysics Data System (ADS)

Mazza, G.; Cometti, S.

2018-03-01

The High Luminosity LHC (HL-LHC) will require a significant upgrade of the readout electronics for the CMS Electromagnetic Calorimeter (ECAL). The Very Front-End (VFE) output signal will be sampled at 160 MS/s (i.e. four times the current sampling rate) with a 13 bits resolution. Therefore, a high-speed, high-resolution ADC is required. Moreover, each readout channel will produce 2.08 Gb/s, thus requiring a fast data transmission circuitry. A new readout architecture, based on two 12 bit, 160 MS/s ADCs, lossless data compression algorithms and fast serial links have been developed for the ECAL upgrade. These functions will be integrated in a single ASIC which is currently under design in a commercial CMOS 65 nm technology using radiation damage mitigation techniques.

ACE: Automatic Centroid Extractor for real time target tracking

NASA Technical Reports Server (NTRS)

Cameron, K.; Whitaker, S.; Canaris, J.

1990-01-01

A high performance video image processor has been implemented which is capable of grouping contiguous pixels from a raster scan image into groups and then calculating centroid information for each object in a frame. The algorithm employed to group pixels is very efficient and is guaranteed to work properly for all convex shapes as well as most concave shapes. Processing speeds are adequate for real time processing of video images having a pixel rate of up to 20 million pixels per second. Pixels may be up to 8 bits wide. The processor is designed to interface directly to a transputer serial link communications channel with no additional hardware. The full custom VLSI processor was implemented in a 1.6 mu m CMOS process and measures 7200 mu m on a side.

Implementation of data acquisition interface using on-board field-programmable gate array (FPGA) universal serial bus (USB) link

NASA Astrophysics Data System (ADS)

Yussup, N.; Ibrahim, M. M.; Lombigit, L.; Rahman, N. A. A.; Zin, M. R. M.

2014-02-01

Typically a system consists of hardware as the controller and software which is installed in the personal computer (PC). In the effective nuclear detection, the hardware involves the detection setup and the electronics used, with the software consisting of analysis tools and graphical display on PC. A data acquisition interface is necessary to enable the communication between the controller hardware and PC. Nowadays, Universal Serial Bus (USB) has become a standard connection method for computer peripherals and has replaced many varieties of serial and parallel ports. However the implementation of USB is complex. This paper describes the implementation of data acquisition interface between a field-programmable gate array (FPGA) board and a PC by exploiting the USB link of the FPGA board. The USB link is based on an FTDI chip which allows direct access of input and output to the Joint Test Action Group (JTAG) signals from a USB host and a complex programmable logic device (CPLD) with a 24 MHz clock input to the USB link. The implementation and results of using the USB link of FPGA board as the data interfacing are discussed.

Implementation of data acquisition interface using on-board field-programmable gate array (FPGA) universal serial bus (USB) link

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yussup, N.; Ibrahim, M. M.; Lombigit, L.

Typically a system consists of hardware as the controller and software which is installed in the personal computer (PC). In the effective nuclear detection, the hardware involves the detection setup and the electronics used, with the software consisting of analysis tools and graphical display on PC. A data acquisition interface is necessary to enable the communication between the controller hardware and PC. Nowadays, Universal Serial Bus (USB) has become a standard connection method for computer peripherals and has replaced many varieties of serial and parallel ports. However the implementation of USB is complex. This paper describes the implementation of datamore » acquisition interface between a field-programmable gate array (FPGA) board and a PC by exploiting the USB link of the FPGA board. The USB link is based on an FTDI chip which allows direct access of input and output to the Joint Test Action Group (JTAG) signals from a USB host and a complex programmable logic device (CPLD) with a 24 MHz clock input to the USB link. The implementation and results of using the USB link of FPGA board as the data interfacing are discussed.« less

Copper link evaluations/solutions for fiber channel, SSA, SONET, ATM, and other services through 4 Gb/sec: basic information, test results, and evaluation

NASA Astrophysics Data System (ADS)

Leib, Michael J.

1995-10-01

Technitrol, the original designer of MIL-STD-1553 transformers, the original military 1Mb/s LAN, has advanced the state of the art one further notch, introducing a series of transceivers that allow high speed (through 1 Gb/s) data transmission over copper wire instead of fiber optic cable. One such device can be employed to implement the Fiber Channel Interface as defined by hte X3T11 ANSI Fibre Channel Committee using either mini coax, Type 1 shielded twisted pair, twinax or video cable. The technology now exists to upgrade data transmission rates on current physical media to speeds formerly only available with fiber optic cabling. Copper transceiver technology provides a cost effective alternative for dealing with demanding high speed applications such as high speed serial data transfer, high speed disk and tape storage transfer, imaging telemetry, radar, and other avionics applications. Eye diagrams will be presented to show that excellent data transmission at rates of 1 gigabit/sec with low jitter is capable over mini coax at distances to approximately 50 meters, shielded twisted pair and twinax cable to distances of 105 meters, and video cable to distances of 175 meters. Distances are further at lower data rates. As a member of the X3T11 ANSI Fiber Channel Committee, Technitrol has developed a Physical Media (copper wire) Dependant (PMD) transceiver not only compliant with the Fibre Channel Specifications but exceeding the specifications by a factor greater than four. Conceivably, this opens high speed interconnections for today's high data rate requirements to copper cabling systems. Fibre Optic problems need not be dealt with to obtain data transfers for high speed information transfers.

Closed-Loop Analysis of Soft Decisions for Serial Links

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin A.; Steele, Glen F.; Zucha, Joan P.; Schlensinger, Adam M.

2012-01-01

Modern receivers are providing soft decision symbol synchronization as radio links are challenged to push more data and more overhead through noisier channels, and software-defined radios use error-correction techniques that approach Shannon s theoretical limit of performance. The authors describe the benefit of closed-loop measurements for a receiver when paired with a counterpart transmitter and representative channel conditions. We also describe a real-time Soft Decision Analyzer (SDA) implementation for closed-loop measurements on single- or dual- (orthogonal) channel serial data communication links. The analyzer has been used to identify, quantify, and prioritize contributors to implementation loss in real-time during the development of software defined radios.

Quick, sensitive serial NMR experiments with Radon transform.

PubMed

Dass, Rupashree; Kasprzak, Paweł; Kazimierczuk, Krzysztof

2017-09-01

The Radon transform is a potentially powerful tool for processing the data from serial spectroscopic experiments. It makes it possible to decode the rate at which frequencies of spectral peaks shift under the effect of changing conditions, such as temperature, pH, or solvent. In this paper we show how it also improves speed and sensitivity, especially in multidimensional experiments. This is particularly important in the case of low-sensitivity techniques, such as NMR spectroscopy. As an example, we demonstrate how Radon transform processing allows serial measurements of 15 N-HSQC spectra of unlabelled peptides that would otherwise be infeasible. Copyright © 2017 Elsevier Inc. All rights reserved.

A Frequency Agile, Self-Adaptive Serial Link on Xilinx FPGAs

NASA Astrophysics Data System (ADS)

Aloisio, A.; Giordano, R.; Izzo, V.; Perrella, S.

2015-06-01

In this paper, we focused on the GTX transceiver modules of Xilinx Kintex 7 field-programmable gate arrays (FPGAs), which provide high bandwidth, low jitter on the recovered clock, and an equalization system on the transmitter and the receiver. We present a frequency agile, auto-adaptive serial link. The link is able to take care of the reconfiguration of the GTX parameters in order to fully benefit from the available link bandwidth, by setting the highest line rate. It is designed around an FPGA-embedded microprocessor, which drives the programmable ports of the GTX in order to control the quality of the received data and to easily calculate the bit-error rate in each sampling point of the eye diagram. We present the self-adaptive link project, the description of the test system, and the main results.

High-Speed and Scalable Whole-Brain Imaging in Rodents and Primates.

PubMed

Seiriki, Kaoru; Kasai, Atsushi; Hashimoto, Takeshi; Schulze, Wiebke; Niu, Misaki; Yamaguchi, Shun; Nakazawa, Takanobu; Inoue, Ken-Ichi; Uezono, Shiori; Takada, Masahiko; Naka, Yuichiro; Igarashi, Hisato; Tanuma, Masato; Waschek, James A; Ago, Yukio; Tanaka, Kenji F; Hayata-Takano, Atsuko; Nagayasu, Kazuki; Shintani, Norihito; Hashimoto, Ryota; Kunii, Yasuto; Hino, Mizuki; Matsumoto, Junya; Yabe, Hirooki; Nagai, Takeharu; Fujita, Katsumasa; Matsuda, Toshio; Takuma, Kazuhiro; Baba, Akemichi; Hashimoto, Hitoshi

2017-06-21

Subcellular resolution imaging of the whole brain and subsequent image analysis are prerequisites for understanding anatomical and functional brain networks. Here, we have developed a very high-speed serial-sectioning imaging system named FAST (block-face serial microscopy tomography), which acquires high-resolution images of a whole mouse brain in a speed range comparable to that of light-sheet fluorescence microscopy. FAST enables complete visualization of the brain at a resolution sufficient to resolve all cells and their subcellular structures. FAST renders unbiased quantitative group comparisons of normal and disease model brain cells for the whole brain at a high spatial resolution. Furthermore, FAST is highly scalable to non-human primate brains and human postmortem brain tissues, and can visualize neuronal projections in a whole adult marmoset brain. Thus, FAST provides new opportunities for global approaches that will allow for a better understanding of brain systems in multiple animal models and in human diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

High-speed clock recovery unit based on a phase aligner

NASA Astrophysics Data System (ADS)

Tejera, Efrain; Esper-Chain, Roberto; Tobajas, Felix; De Armas, Valentin; Sarmiento, Roberto

2003-04-01

Nowadays clock recovery units are key elements in high speed digital communication systems. For an efficient operation, this units should generate a low jitter clock based on the NRZ received data, and be tolerant to long absence of transitions. Architectures based on Hogge phase detectors have been widely used, nevertheless, they are very sensitive to jitter of the received data and they have a limited tolerance to the absence of transitions. This paper shows a novel high speed clock recovery unit based on a phase aligner. The system allows a very fast clock recovery with a low jitter, moreover, it is very resistant to absence of transitions. The design is based on eight phases obtained from a reference clock running at the nominal frequency of the received signal. This high speed reference clock is generated using a crystal and a clock multiplier unit. The phase alignment system chooses, as starting point, the two phases closest to the data phase. This allows a maximum error of 45 degrees between the clock and data signal phases. Furthermore, the system includes a feed-back loop that interpolates the chosen phases to reduce the phase error to zero. Due to the high stability and reduced tolerance of the local reference clock, the jitter obtained is highly reduced and the system becomes able to operate under long absence of transitions. This performances make this design suitable for systems such as high speed serial link technologies. This system has been designed for CMOS 0.25μm at 1.25GHz and has been verified through HSpice simulations.

Piezoelectric micromotor based on the structure of serial bending arms.

PubMed

Tong, Jianhua; Cui, Tianhong; Shao, Peige; Wang, Liding

2003-09-01

This paper presents a new piezoelectric micromotor based on the structure of serial bending arms. Serial bending arms are composed of two piezoelectric bimorphs with one end fixed and the other end free, driven by two signals of a biased square wave with a phase difference of pi/2. The free end of a cantilever arm will move along an elliptic orbit so that the cantilever is used to drive a cylinder rotor. The rotor's end surface contacts the free end of the cantilever, resulting in the rotor's rotation. There are six serial bending arms anchored on the base. The driving mechanism of the micromotor is proposed and analyzed. A new micromotor prototype, 5 mm in diameter, has been fabricated and characterized. The maximum rotational speed reaches 325 rpm, and the output torque is about 36.5 microNm.

Demand/Withdraw Patterns in Serial Arguments: Implications for Well-Being

ERIC Educational Resources Information Center

Malis, Rachel S.; Roloff, Michael E.

2006-01-01

Serial arguing has been linked to relational difficulties. We extend this research by looking at the relationship between demand/withdraw patterns enacted during argumentative episodes and aversive reactions after the episode has ended in romantic relationships ("N" = 219). We found that individuals who initiated the first confrontation often…

Serials Solutions and LinkFinderPlus at the University of Wales Swansea

ERIC Educational Resources Information Center

Brown, Andrew; Smyth, Neil

2005-01-01

Purpose: To provide practical information on two electronic journal-related products implemented in Library and Information Services at University of Wales Swansea. Design/methodology/approach: An overview is provided of the evaluation of electronic journal management products undertaken and subsequent implementation. Findings: Serials Solutions…

A comparison between the original and Tablet-based Symbol Digit Modalities Test in patients with schizophrenia: Test-retest agreement, random measurement error, practice effect, and ecological validity.

PubMed

Tang, Shih-Fen; Chen, I-Hui; Chiang, Hsin-Yu; Wu, Chien-Te; Hsueh, I-Ping; Yu, Wan-Hui; Hsieh, Ching-Lin

2017-11-27

We aimed to compare the test-retest agreement, random measurement error, practice effect, and ecological validity of the original and Tablet-based Symbol Digit Modalities Test (T-SDMT) over five serial assessments, and to examine the concurrent validity of the T-SDMT in patients with schizophrenia. Sixty patients with chronic schizophrenia completed five serial assessments (one week apart) of the SDMT and T-SDMT and one assessment of the Activities of Daily Living Rating Scale III at the first time point. Both measures showed high test-retest agreement, similar levels of random measurement error over five serial assessments. Moreover, the practice effects of the two measures did not reach a plateau phase after five serial assessments in young and middle-aged participants. Nevertheless, only the practice effect of the T-SDMT became trivial after the first assessment. Like the SDMT, the T-SDMT had good ecological validity. The T-SDMT also had good concurrent validity with the SDMT. In addition, only the T-SDMT had discriminative validity to discriminate processing speed in young and middle-aged participants. Compared to the SDMT, the T-SDMT had overall slightly better psychometric properties, so it can be an alternative measure to the SDMT for assessing processing speed in patients with schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Adding HDLC Framing to CCSDS Recommendations

NASA Technical Reports Server (NTRS)

Hogie, Keith; Criscuolo, Ed; Parise, Ron

2004-01-01

Current Space IP missions use High-Level Data Link Control (HDLC) framing to provide standard serial link interfaces over a space link. HDLC is the standard framing technique used by all routers over clock and data serial lines and is also the basic framing used in all Frame Relay services which are widely deployed in national and international communication networks. In late 2003 a presentation was made to CCSDS committees to initiate discussion on including HDLC in the CCSDS recommendations for space systems. This presentation will summarize the differences between variable length HDLC frames and fixed length CCSDS frames. It will also discuss where and how HDLC framing would fit into the overall CCSDS structures.

High speed imaging television system

DOEpatents

Wilkinson, William O.; Rabenhorst, David W.

1984-01-01

A television system for observing an event which provides a composite video output comprising the serially interlaced images the system is greater than the time resolution of any of the individual cameras.

76 FR 72091 - Airworthiness Directives; Turbomeca S.A. Makila 1A2 Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-22

... inadvertent activation of the 65% N1 (gas generator speed) back up control mode. The subsequent technical investigations carried by Turbomeca revealed that an N2 (power turbine speed) sensor harness wire crimping... the conclusion that N2 sensor Part Number (P/N) 0 301 52 001 0 whose Serial Numbers (S/N) are between...

Implementation of a Serial Delay Insertion Type Loop Communication for a Real Time Multitransputer System.

DTIC Science & Technology

1985-06-01

just pass the message WAIT NOW AFTER Rlock + timeo t -- if time is out write.screen( TIME IS OUT") MAIN PROGRAM* CHAN linki , link2, link3, link4...PAR D.I.Loop.Interface (link4, linkl,) D.I.Loop.Interface ( linki , link2, 2) D.I.Loop.Interface (link2, link3, 3) JD.I Loop.Interface (link3, link4, 4

Spatial-frequency requirements for reading revisited

PubMed Central

Kwon, MiYoung; Legge, Gordon E.

2012-01-01

Blur is one of many visual factors that can limit reading in both normal and low vision. Legge et al. [Legge, G. E., Pelli, D. G., Rubin, G. S., & Schleske, M. M. (1985). Psychophysics of reading. I. Normal vision. Vision Research, 25, 239–252.] measured reading speed for text that was low-pass filtered with a range of cutoff spatial frequencies. Above 2 cycles per letter (CPL) reading speed was constant at its maximum level, but decreased rapidly for lower cutoff frequencies. It remains unknown why the critical cutoff for reading speed is near 2 CPL. The goal of the current study was to ask whether the spatial-frequency requirement for rapid reading is related to the effects of cutoff frequency on letter recognition and the size of the visual span. Visual span profiles were measured by asking subjects to recognize letters in trigrams (random strings of three letters) flashed for 150 ms at varying letter positions left and right of the fixation point. Reading speed was measured with Rapid Serial Visual Presentation (RSVP). The size of the visual span and reading speed were measured for low-pass filtered stimuli with cutoff frequencies from 0.8 to 8 CPL. Low-pass letter recognition data, obtained under similar testing conditions, were available from our previous study (Kwon & Legge, 2011). We found that the spatial-frequency requirement for reading is very similar to the spatial-frequency requirements for the size of the visual span and single letter recognition. The critical cutoff frequencies for reading speed, the size of the visual span and a contrast-invariant measure of letter recognition were all near 1.4 CPL, which is lower than the previous estimate of 2 CPL for reading speed. Although correlational in nature, these results are consistent with the hypothesis that the size of the visual span is closely linked to reading speed. PMID:22521659

Encoding Speed, Rehearsal, and Probed Recall of Dyslexic Boys

ERIC Educational Resources Information Center

Spring, Carl; Capps, Carolyn

1974-01-01

The interaction of reading ability with serial position indicates that short-term storage is equally robust for dyslexics and normals but that long-term storage is impaired for dyslexics. (Author/BJG)

Scalable Multiprocessor for High-Speed Computing in Space

NASA Technical Reports Server (NTRS)

Lux, James; Lang, Minh; Nishimoto, Kouji; Clark, Douglas; Stosic, Dorothy; Bachmann, Alex; Wilkinson, William; Steffke, Richard

2004-01-01

A report discusses the continuing development of a scalable multiprocessor computing system for hard real-time applications aboard a spacecraft. "Hard realtime applications" signifies applications, like real-time radar signal processing, in which the data to be processed are generated at "hundreds" of pulses per second, each pulse "requiring" millions of arithmetic operations. In these applications, the digital processors must be tightly integrated with analog instrumentation (e.g., radar equipment), and data input/output must be synchronized with analog instrumentation, controlled to within fractions of a microsecond. The scalable multiprocessor is a cluster of identical commercial-off-the-shelf generic DSP (digital-signal-processing) computers plus generic interface circuits, including analog-to-digital converters, all controlled by software. The processors are computers interconnected by high-speed serial links. Performance can be increased by adding hardware modules and correspondingly modifying the software. Work is distributed among the processors in a parallel or pipeline fashion by means of a flexible master/slave control and timing scheme. Each processor operates under its own local clock; synchronization is achieved by broadcasting master time signals to all the processors, which compute offsets between the master clock and their local clocks.

A bi-directional fixed-latency clock distribution system

NASA Astrophysics Data System (ADS)

Yang, Y.; Ó Murchadha, A.; Meures, T.; Korntheuer, M.; Hanson, K.

2013-12-01

The Askar'yan Radio Array (ARA) Collaboration is constructing a giant array of radio-frequency antennas deployed in the ice near the geographic South Pole. This experiment aims at detecting the extremely weak signal of neutrinos with energies in excess of 100 PeV from ultrahigh-energy cosmic ray interactions with the cosmic microwave background radiation. The antennas are located in shallow holes drilled to depths of 200 m and need high fidelity RF signal transmission over extended lengths to the data acquisition logic at the surface. We report on a transmission scheme whereby signals are digitized in the ice and the waveforms are digitally sent via high-speed serial links. Reconstruction algorithms require distribution of a low-jitter clock from the surface down to the digitization boards in the holes with knowledge of the overall time delay between the two clock domains. Previously, we designed a clock synchronization system using electrical signaling over CAT5. This year we have updated our solution to optical fibers using high speed transceiver blocks in Spartan-6 FPGAs. This note describes our improvements on the latter solution: technical details as well as methods of maintaining a fixed phase between two clocks after power cycles and resets.

Status of the Electromagnetic Calorimeter Trigger system at the Belle II experiment

NASA Astrophysics Data System (ADS)

Kim, S. H.; Lee, I. S.; Unno, Y.; Cheon, B. G.

2017-09-01

The Belle II experiment at the SuperKEKB collider in Japan has been under the construction toward a physics run in 2018 with an ultimate target of 40 times higher instantaneous luminosity than the KEKB collider. The main physics motivation is to search for the New Physics from heavy quark/lepton flavor decays. In order to select an event of interest efficiently under much higher luminosity and beam background environment than the KEKB, we have upgraded the Electromagnetic Calorimeter (ECL) hardware trigger system. It would be realized by the improvement of ECL trigger logic based on two main triggers, the total energy and the number of clusters, with an FPGA-based flexible architecture and a high speed serial link for the data transfer. We report the current status of hardware, firmware, and software that has been achieved so far. The overall scheme of the system will be presented as well.

Linking School and Work to Accelerate Student Results.

ERIC Educational Resources Information Center

Workforce Economics, 1999

1999-01-01

This serial issue focusing on the theme of "School-to-Work." The two articles it contains describe promising practices that benefit individual students who participate. The first article, "Connecting the Dots: Linking School and Work to Accelerate Student Results," examines how schools and businesses are linking up, leading to benefits for…

28-Bit serial word simulator/monitor

NASA Technical Reports Server (NTRS)

Durbin, J. W.

1979-01-01

Modular interface unit transfers data at high speeds along four channels. Device expedites variable-word-length communication between computers. Operation eases exchange of bit information by automatically reformatting coded input data and status information to match requirements of output.

Short-term memory for serial order supports vocabulary development: new evidence from a novel word learning paradigm.

PubMed

Majerus, Steve; Boukebza, Claire

2013-12-01

Although recent studies suggest a strong association between short-term memory (STM) for serial order and lexical development, the precise mechanisms linking the two domains remain to be determined. This study explored the nature of these mechanisms via a microanalysis of performance on serial order STM and novel word learning tasks. In the experiment, 6- and 7-year-old children were administered tasks maximizing STM for either item or serial order information as well as paired-associate learning tasks involving the learning of novel words, visual symbols, or familiar word pair associations. Learning abilities for novel words were specifically predicted by serial order STM abilities. A measure estimating the precision of serial order coding predicted the rate of correct repetitions and the rate of phoneme migration errors during the novel word learning process. In line with recent theoretical accounts, these results suggest that serial order STM supports vocabulary development via ordered and detailed reactivation of the novel phonological sequences that characterize new words. Copyright © 2013 Elsevier Inc. All rights reserved.

The Temporal Dynamics of Visual Search: Evidence for Parallel Processing in Feature and Conjunction Searches

PubMed Central

McElree, Brian; Carrasco, Marisa

2012-01-01

Feature and conjunction searches have been argued to delineate parallel and serial operations in visual processing. The authors evaluated this claim by examining the temporal dynamics of the detection of features and conjunctions. The 1st experiment used a reaction time (RT) task to replicate standard mean RT patterns and to examine the shapes of the RT distributions. The 2nd experiment used the response-signal speed–accuracy trade-off (SAT) procedure to measure discrimination (asymptotic detection accuracy) and detection speed (processing dynamics). Set size affected discrimination in both feature and conjunction searches but affected detection speed only in the latter. Fits of models to the SAT data that included a serial component overpredicted the magnitude of the observed dynamics differences. The authors concluded that both features and conjunctions are detected in parallel. Implications for the role of attention in visual processing are discussed. PMID:10641310

Performance of a 300 Mbps 1:16 serial/parallel optoelectronic receiver module

NASA Technical Reports Server (NTRS)

Richard, M. A.; Claspy, P. C.; Bhasin, K. B.; Bendett, M. B.

1990-01-01

Optical interconnects are being considered for the high speed distribution of multiplexed control signals in GaAs monolithic microwave integrated circuit (MMIC) based phased array antennas. The performance of a hybrid GaAs optoelectronic integrated circuit (OEIC) is described, as well as its design and fabrication. The OEIC converts a 16-bit serial optical input to a 16 parallel line electrical output using an on-board 1:16 demultiplexer and operates at data rates as high as 30b Mbps. The performance characteristics and potential applications of the device are presented.

Serial number coding and decoding by laser interference direct patterning on the original product surface for anti-counterfeiting.

PubMed

Park, In-Yong; Ahn, Sanghoon; Kim, Youngduk; Bae, Han-Sung; Kang, Hee-Shin; Yoo, Jason; Noh, Jiwhan

2017-06-26

Here, we investigate a method to distinguish the counterfeits by patterning multiple reflective type grating directly on the surface of the original product and analyze the serial number from its rotation angles of diffracted fringes. The micro-sized gratings were fabricated on the surface of the material at high speeds by illuminating the interference fringe generated by passing a high-energy pulse laser through the Fresnel biprism. In addition, analysis of the grating's diffraction fringes was performed using a continuous wave laser.

On the Function of Stress Rhythms in Speech: Evidence of a Link with Grouping Effects on Serial Memory

ERIC Educational Resources Information Center

Boucher, Victor J.

2006-01-01

Language learning requires a capacity to recall novel series of speech sounds. Research shows that prosodic marks create grouping effects enhancing serial recall. However, any restriction on memory affecting the reproduction of prosody would limit the set of patterns that could be learned and subsequently used in speech. By implication, grouping…

Parallel Monotonic Basin Hopping for Low Thrust Trajectory Optimization

NASA Technical Reports Server (NTRS)

McCarty, Steven L.; McGuire, Melissa L.

2018-01-01

Monotonic Basin Hopping has been shown to be an effective method of solving low thrust trajectory optimization problems. This paper outlines an extension to the common serial implementation by parallelizing it over any number of available compute cores. The Parallel Monotonic Basin Hopping algorithm described herein is shown to be an effective way to more quickly locate feasible solutions, and improve locally optimal solutions in an automated way without requiring a feasible initial guess. The increased speed achieved through parallelization enables the algorithm to be applied to more complex problems that would otherwise be impractical for a serial implementation. Low thrust cislunar transfers and a hybrid Mars example case demonstrate the effectiveness of the algorithm. Finally, a preliminary scaling study quantifies the expected decrease in solve time compared to a serial implementation.,

The crew activity planning system bus interface unit

NASA Technical Reports Server (NTRS)

Allen, M. A.

1979-01-01

The hardware and software designs used to implement a high speed parallel communications interface to the MITRE 307.2 kilobit/second serial bus communications system are described. The primary topic is the development of the bus interface unit.

Generic Bluetooth Data Module

DTIC Science & Technology

2002-09-01

to Ref (1). 34 RS232.java Serial Coomunication port class To Bluetooth module HCI.java Host Control Interface class L2CAP.java Logical Link Control...standard protocol for transporting IP datagrams over point-to-point link . It is designed to run over RFCOMM to accomplish point-to-point connections...Control and Adaption Host Controller Interface Link Manager Baseband / Link Controller Radio Figure 2. Bluetooth layers (From Ref. [3].) C

Closed-Loop Analysis of Soft Decisions for Serial Links

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin A.; Steele, Glen F.; Zucha, Joan P.; Schlesinger, Adam M.

2013-01-01

We describe the benefit of using closed-loop measurements for a radio receiver paired with a counterpart transmitter. We show that real-time analysis of the soft decision output of a receiver can provide rich and relevant insight far beyond the traditional hard-decision bit error rate (BER) test statistic. We describe a Soft Decision Analyzer (SDA) implementation for closed-loop measurements on single- or dual- (orthogonal) channel serial data communication links. The analyzer has been used to identify, quantify, and prioritize contributors to implementation loss in live-time during the development of software defined radios. This test technique gains importance as modern receivers are providing soft decision symbol synchronization as radio links are challenged to push more data and more protocol overhead through noisier channels, and software-defined radios (SDRs) use error-correction codes that approach Shannon's theoretical limit of performance.

Pupil-linked arousal is driven by decision uncertainty and alters serial choice bias

NASA Astrophysics Data System (ADS)

Urai, Anne E.; Braun, Anke; Donner, Tobias H.

2017-03-01

While judging their sensory environments, decision-makers seem to use the uncertainty about their choices to guide adjustments of their subsequent behaviour. One possible source of these behavioural adjustments is arousal: decision uncertainty might drive the brain's arousal systems, which control global brain state and might thereby shape subsequent decision-making. Here, we measure pupil diameter, a proxy for central arousal state, in human observers performing a perceptual choice task of varying difficulty. Pupil dilation, after choice but before external feedback, reflects three hallmark signatures of decision uncertainty derived from a computational model. This increase in pupil-linked arousal boosts observers' tendency to alternate their choice on the subsequent trial. We conclude that decision uncertainty drives rapid changes in pupil-linked arousal state, which shape the serial correlation structure of ongoing choice behaviour.

Serial Back-Plane Technologies in Advanced Avionics Architectures

NASA Technical Reports Server (NTRS)

Varnavas, Kosta

2005-01-01

Current back plane technologies such as VME, and current personal computer back planes such as PCI, are shared bus systems that can exhibit nondeterministic latencies. This means a card can take control of the bus and use resources indefinitely affecting the ability of other cards in the back plane to acquire the bus. This provides a real hit on the reliability of the system. Additionally, these parallel busses only have bandwidths in the 100s of megahertz range and EMI and noise effects get worse the higher the bandwidth goes. To provide scalable, fault-tolerant, advanced computing systems, more applicable to today s connected computing environment and to better meet the needs of future requirements for advanced space instruments and vehicles, serial back-plane technologies should be implemented in advanced avionics architectures. Serial backplane technologies eliminate the problem of one card getting the bus and never relinquishing it, or one minor problem on the backplane bringing the whole system down. Being serial instead of parallel improves the reliability by reducing many of the signal integrity issues associated with parallel back planes and thus significantly improves reliability. The increased speeds associated with a serial backplane are an added bonus.

77 FR 1654 - Airworthiness Directives; Agusta S.p.A. Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-11

... a ``T'' marked after the serial number, or Inspect the link assembly for the torsion value force of...-service, remove the link assembly from the helicopter and inspect the torsion value force of the ball bearing rotation. If the torsion value force in either end of the link assembly is greater than 7.30 N...

Mindfulness facets, trait emotional intelligence, emotional distress, and multiple health behaviors: A serial two-mediator model.

PubMed

Jacobs, Ingo; Wollny, Anna; Sim, Chu-Won; Horsch, Antje

2016-06-01

In the present study, we tested a serial mindfulness facets-trait emotional intelligence (TEI)-emotional distress-multiple health behaviors mediation model in a sample of N = 427 German-speaking occupational therapists. The mindfulness facets-TEI-emotional distress section of the mediation model revealed partial mediation for the mindfulness facets Act with awareness (Act/Aware) and Accept without judgment (Accept); inconsistent mediation was found for the Describe facet. The serial two-mediator model included three mediational pathways that may link each of the four mindfulness facets with multiple health behaviors. Eight out of 12 indirect effects reached significance and fully mediated the links between Act/Aware and Describe to multiple health behaviors; partial mediation was found for Accept. The mindfulness facet Observe was most relevant for multiple health behaviors, but its relation was not amenable to mediation. Implications of the findings will be discussed. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

A Combined Cognitive Stimulation and Physical Exercise Programme (MINDVital) in Early Dementia: Differential Effects on Single- and Dual-Task Gait Performance.

PubMed

Tay, Laura; Lim, Wee Shiong; Chan, Mark; Ali, Noorhazlina; Chong, Mei Sian

2016-01-01

Gait disorders are common in early dementia, with particularly pronounced dual-task deficits, contributing to the increased fall risk and mobility decline associated with cognitive impairment. This study examines the effects of a combined cognitive stimulation and physical exercise programme (MINDVital) on gait performance under single- and dual-task conditions in older adults with mild dementia. Thirty-nine patients with early dementia participated in a multi-disciplinary rehabilitation programme comprising both physical exercise and cognitive stimulation. The programme was conducted in 8-week cycles with participants attending once weekly, and all participants completed 2 successive cycles. Cognitive, functional performance and behavioural symptoms were assessed at baseline and at the end of each 8-week cycle. Gait speed was examined under both single- (Timed Up and Go and 6-metre walk tests) and dual-task (animal category and serial counting) conditions. A random effects model was performed for the independent effect of MINDVital on the primary outcome variable of gait speed under dual-task conditions. The mean age of patients enroled in the rehabilitation programme was 79 ± 6.2 years; 25 (64.1%) had a diagnosis of Alzheimer's dementia, and 26 (66.7%) were receiving a cognitive enhancer therapy. There was a significant improvement in cognitive performance [random effects coefficient (standard error) = 0.90 (0.31), p = 0.003] and gait speed under both dual-task situations [animal category: random effects coefficient = 0.04 (0.02), p = 0.039; serial counting: random effects coefficient = 0.05 (0.02), p = 0.013], with reduced dual-task cost for gait speed [serial counting: random effects coefficient = -4.05 (2.35), p = 0.086] following successive MINDVital cycles. No significant improvement in single-task gait speed was observed. Improved cognitive performance over time was a significant determinant of changes in dual-task gait speed [random effects coefficients = 0.01 (0.005), p = 0.048, and 0.02 (0.005), p = 0.003 for category fluency and counting backwards, respectively]. A combined physical and cognitive rehabilitation programme leads to significant improvements in dual-task walking in early dementia, which may be contributed by improvement in cognitive performance, as single-task gait performance remained stable. © 2016 S. Karger AG, Basel.

Serial agonistic attacks by greylag goose families, Anser anser, against the same opponent

PubMed Central

Scheiber, Isabella B.R.; Kotrschal, Kurt; Weiß, Brigitte M.

2011-01-01

It is known from primates that alliance partners may support each other’s interests in competition with others, for example, through repeated agonistic attacks against a particular individual. We examined serial aggressive interactions between greylag goose families and other flock members. We found that repeated attacks towards the same individual were common and that up to five serial attacks by family members followed an initial attack. Family size did not affect the frequency of such serial attacks. Juvenile geese evidently benefited most from active social support through serial attacks. About 60% of the juveniles’ lost primary interactions were subsequently reversed by another family member. This may be one of the reasons why juveniles rank higher in the social hierarchy than would be expected from their age and size alone. Losses in serial attacks predominantly occurred against other, presumably higher-ranking, family geese and ganders. We propose three major functions/consequences of serial attacks. Analogous to primates, serial attacks in greylag geese may serve to reinforce a losing experience of an opponent defeated in a preceding attack. On the side of the winning family, serial attacks may reinforce the experience of winning. Both winning and losing experiences are linked with physiological consequences in higher vertebrates, affecting the future social performance of winners or losers. Finally, serial attacks may signal the agonistic potential of a family to other flock members. This is supported by heart rate data, which indicate that greylags are competent to interpret third-party relationships. PMID:21984838

Linking memory and language: Evidence for a serial-order learning impairment in dyslexia.

PubMed

Bogaerts, Louisa; Szmalec, Arnaud; Hachmann, Wibke M; Page, Mike P A; Duyck, Wouter

2015-01-01

The present study investigated long-term serial-order learning impairments, operationalized as reduced Hebb repetition learning (HRL), in people with dyslexia. In a first multi-session experiment, we investigated both the persistence of a serial-order learning impairment as well as the long-term retention of serial-order representations, both in a group of Dutch-speaking adults with developmental dyslexia and in a matched control group. In a second experiment, we relied on the assumption that HRL mimics naturalistic word-form acquisition and we investigated the lexicalization of novel word-forms acquired through HRL. First, our results demonstrate that adults with dyslexia are fundamentally impaired in the long-term acquisition of serial-order information. Second, dyslexic and control participants show comparable retention of the long-term serial-order representations in memory over a period of 1 month. Third, the data suggest weaker lexicalization of newly acquired word-forms in the dyslexic group. We discuss the integration of these findings into current theoretical views of dyslexia. Copyright © 2015 Elsevier Ltd. All rights reserved.

A 1024×768-12μm Digital ROIC for uncooled microbolometer FPAs

NASA Astrophysics Data System (ADS)

Eminoglu, Selim

2017-02-01

This paper reports the development of a new digital microbolometer Readout Integrated Circuit (D-ROIC), called MT10212BD. It has a format of 1024 × 768 (XGA) and a pixel pitch of 12μm. MT10212BD is Mikro Tasarim's second 12μm pitch microbolometer ROIC, which is developed specifically for surface micro machined microbolometer detector arrays with small pixel pitch using high-TCR pixel materials, such as VOx and a Si. MT10212BD has an alldigital system on-chip architecture, which generates programmable timing and biasing, and performs 14-bit analog to digital conversion (ADC). The signal processing chain in the ROIC is composed of pixel bias circuitry, integrator based programmable gain amplifier followed by column parallel ADC circuitry. MT10212BD has a serial programming interface that can be used to configure the programmable ROIC features and to load the Non-Uniformity-Correction (NUC) date to the ROIC. MT10212BD has a total of 8 high-speed serial digital video outputs, which can be programmed to operate in the 2, 4, and 8-output modes and can support frames rates above 60 fps. The high-speed serial digital outputs supports data rates as high as 400 Mega-bits/s, when operated at 50 MHz system clock frequency. There is an on-chip phase-locked-loop (PLL) based timing circuitry to generate the high speed clocks used in the ROIC. The ROIC is designed to support pixel resistance values ranging from 30KΩ to 90kΩ, with a nominal value of 60KΩ. The ROIC has a globally programmable gain in the column readout, which can be adjusted based on the detector resistance value.

Internet Connections: Understanding Your Access Options.

ERIC Educational Resources Information Center

Notess, Greg R.

1994-01-01

Describes levels of Internet connectivity, physical connections, and connection speeds. Compares options for connecting to the Internet, including terminal accounts, dial-up terminal accounts, direct connections through a local area network, and direct connections using SLIP (Serial Line Internet Protocol) or PPP (Point-to-Point Protocol). (eight…

Measurements in Flight of the Longitudinal-Stability Characteristics of a Republic YF-84A Airplane (Army Serial No. 45-59488) at High Subsonic Mach Numbers

NASA Technical Reports Server (NTRS)

Turner, Howard L.; Cooper, George E.

1948-01-01

A brief investigation was made of the longitudinal-stability characteristics of a YF-84A airplane (Army Serial No. 45-79488). The airplane developed a pitching-up tendency at approximately 0.80 Mach number which necessitated large push forces and down-elevator deflections for further increases in speed. In steady turns at 35,000 feet with the center of gravity at 28.3 percent mean aerodynamic chord for normal accelerations up to the maximum test value, the control-force gradients were excessive at Mach numbers over 0.78. Airplane buffeting did not present a serious problem in accelerated or unaccelerated flight at 15,000 and 35,000 feet up to the maximum test Mach number of 0.84. It is believed that excessive control force would be the limiting factor in attaining speeds in excess of 0.84 Mach number, especially at altitudes below 35,000 feet.

Verbal short-term memory in individuals with chromosome 22q11.2 deletion: specific deficit in serial order retention capacities?

PubMed

Majerus, Steve; Van der Linden, Martial; Braissand, Vérane; Eliez, Stephan

2007-03-01

Many researchers have recently explored the cognitive profile of velocardiofacial syndrome (VCFS), a neurodevelopmental disorder linked to a 22q11.2 deletion. However, verbal short-term memory has not yet been systematically investigated. We explored verbal short-term memory abilities in a group of 11 children and adults presenting with VCFS and two control groups, matched on either CA or vocabulary knowledge, by distinguishing short-term memory for serial order and item information. The VCFS group showed impaired performance on the serial order short-term memory tasks compared to both control groups. Relative to the vocabulary-matched control group, item short-term memory was preserved. The implication of serial order short-term memory deficits on other aspects of cognitive development in VCFS (e.g., language development, numerical cognition) is discussed.

Flexible Peripheral Component Interconnect Input/Output Card

NASA Technical Reports Server (NTRS)

Bigelow, Kirk K.; Jerry, Albert L.; Baricio, Alisha G.; Cummings, Jon K.

2010-01-01

The Flexible Peripheral Component Interconnect (PCI) Input/Output (I/O) Card is an innovative circuit board that provides functionality to interface between a variety of devices. It supports user-defined interrupts for interface synchronization, tracks system faults and failures, and includes checksum and parity evaluation of interface data. The card supports up to 16 channels of high-speed, half-duplex, low-voltage digital signaling (LVDS) serial data, and can interface combinations of serial and parallel devices. Placement of a processor within the field programmable gate array (FPGA) controls an embedded application with links to host memory over its PCI bus. The FPGA also provides protocol stacking and quick digital signal processor (DSP) functions to improve host performance. Hardware timers, counters, state machines, and other glue logic support interface communications. The Flexible PCI I/O Card provides an interface for a variety of dissimilar computer systems, featuring direct memory access functionality. The card has the following attributes: 8/16/32-bit, 33-MHz PCI r2.2 compliance, Configurable for universal 3.3V/5V interface slots, PCI interface based on PLX Technology's PCI9056 ASIC, General-use 512K 16 SDRAM memory, General-use 1M 16 Flash memory, FPGA with 3K to 56K logical cells with embedded 27K to 198K bits RAM, I/O interface: 32-channel LVDS differential transceivers configured in eight, 4-bit banks; signaling rates to 200 MHz per channel, Common SCSI-3, 68-pin interface connector.

Learning to recognize face shapes through serial exploration.

PubMed

Wallraven, Christian; Whittingstall, Lisa; Bülthoff, Heinrich H

2013-05-01

Human observers are experts at visual face recognition due to specialized visual mechanisms for face processing that evolve with perceptual expertize. Such expertize has long been attributed to the use of configural processing, enabled by fast, parallel information encoding of the visual information in the face. Here we tested whether participants can learn to efficiently recognize faces that are serially encoded-that is, when only partial visual information about the face is available at any given time. For this, ten participants were trained in gaze-restricted face recognition in which face masks were viewed through a small aperture controlled by the participant. Tests comparing trained with untrained performance revealed (1) a marked improvement in terms of speed and accuracy, (2) a gradual development of configural processing strategies, and (3) participants' ability to rapidly learn and accurately recognize novel exemplars. This performance pattern demonstrates that participants were able to learn new strategies to compensate for the serial nature of information encoding. The results are discussed in terms of expertize acquisition and relevance for other sensory modalities relying on serial encoding.

Guidelines for Design and Test of a Built-In Self Test (BIST) Circuit For Space Radiation Studies of High-Speed IC Technologies

NASA Technical Reports Server (NTRS)

Carts, M. A.; Marshall, P. W.; Reed, R.; Curie, S.; Randall, B.; LaBel, K.; Gilbert, B.; Daniel, E.

2006-01-01

Serial Bit Error Rate Testing under radiation to characterize single particle induced errors in high-speed IC technologies generally involves specialized test equipment common to the telecommunications industry. As bit rates increase, testing is complicated by the rapidly increasing cost of equipment able to test at-speed. Furthermore as rates extend into the tens of billions of bits per second test equipment ceases to be broadband, a distinct disadvantage for exploring SEE mechanisms in the target technologies. In this presentation the authors detail the testing accomplished in the CREST project and apply the knowledge gained to establish a set of guidelines suitable for designing arbitrarily high speed radiation effects tests.

Bayer image parallel decoding based on GPU

NASA Astrophysics Data System (ADS)

Hu, Rihui; Xu, Zhiyong; Wei, Yuxing; Sun, Shaohua

2012-11-01

In the photoelectrical tracking system, Bayer image is decompressed in traditional method, which is CPU-based. However, it is too slow when the images become large, for example, 2K×2K×16bit. In order to accelerate the Bayer image decoding, this paper introduces a parallel speedup method for NVIDA's Graphics Processor Unit (GPU) which supports CUDA architecture. The decoding procedure can be divided into three parts: the first is serial part, the second is task-parallelism part, and the last is data-parallelism part including inverse quantization, inverse discrete wavelet transform (IDWT) as well as image post-processing part. For reducing the execution time, the task-parallelism part is optimized by OpenMP techniques. The data-parallelism part could advance its efficiency through executing on the GPU as CUDA parallel program. The optimization techniques include instruction optimization, shared memory access optimization, the access memory coalesced optimization and texture memory optimization. In particular, it can significantly speed up the IDWT by rewriting the 2D (Tow-dimensional) serial IDWT into 1D parallel IDWT. Through experimenting with 1K×1K×16bit Bayer image, data-parallelism part is 10 more times faster than CPU-based implementation. Finally, a CPU+GPU heterogeneous decompression system was designed. The experimental result shows that it could achieve 3 to 5 times speed increase compared to the CPU serial method.

Is processing of symbols and words influenced by writing system? Evidence from Chinese, Korean, English, and Greek.

PubMed

Altani, Angeliki; Georgiou, George K; Deng, Ciping; Cho, Jeung-Ryeul; Katopodi, Katerina; Wei, Wei; Protopapas, Athanassios

2017-12-01

We examined cross-linguistic effects in the relationship between serial and discrete versions of digit naming and word reading. In total, 113 Mandarin-speaking Chinese children, 100 Korean children, 112 English-speaking Canadian children, and 108 Greek children in Grade 3 were administered tasks of serial and discrete naming of words and digits. Interrelations among tasks indicated that the link between rapid naming and reading is largely determined by the format of the tasks across orthographies. Multigroup path analyses with discrete and serial word reading as dependent variables revealed commonalities as well as significant differences between writing systems. The path coefficient from discrete digits to discrete words was greater for the more transparent orthographies, consistent with more efficient sight-word processing. The effect of discrete word reading on serial word reading was stronger in alphabetic languages, where there was also a suppressive effect of discrete digit naming. However, the effect of serial digit naming on serial word reading did not differ among the four language groups. This pattern of relationships challenges a universal account of reading fluency acquisition while upholding a universal role of rapid serial naming, further distinguishing between multi-element interword and intraword processing. Copyright © 2017 Elsevier Inc. All rights reserved.

Implementing An Image Understanding System Architecture Using Pipe

NASA Astrophysics Data System (ADS)

Luck, Randall L.

1988-03-01

This paper will describe PIPE and how it can be used to implement an image understanding system. Image understanding is the process of developing a description of an image in order to make decisions about its contents. The tasks of image understanding are generally split into low level vision and high level vision. Low level vision is performed by PIPE -a high performance parallel processor with an architecture specifically designed for processing video images at up to 60 fields per second. High level vision is performed by one of several types of serial or parallel computers - depending on the application. An additional processor called ISMAP performs the conversion from iconic image space to symbolic feature space. ISMAP plugs into one of PIPE's slots and is memory mapped into the high level processor. Thus it forms the high speed link between the low and high level vision processors. The mechanisms for bottom-up, data driven processing and top-down, model driven processing are discussed.

Browsing for the Best Internet Access Provider?

ERIC Educational Resources Information Center

Weil, Marty

1996-01-01

Highlights points to consider when choosing an Internet Service Provider. Serial Line Internet Protocol (SLIP) and Point to Point Protocol (PPP) are compared regarding price, performance, bandwidth, speed, and technical support. Obtaining access via local, national, consumer online, and telephone-company providers is discussed. A pricing chart and…

System-Level Integration of Mass Memory

NASA Technical Reports Server (NTRS)

Cox, Brian; Mellstrom, Jeffrey; Wysocky, Terry

2008-01-01

A report discusses integrating multiple memory modules on the high-speed serial interconnect (IEEE 1393) that is used by a spacecraft?s inter-module communications in order to ease data congestion and provide for a scalable, strong, flexible system that can meet new system-level mass memory requirements.

Optical links in handheld multimedia devices

NASA Astrophysics Data System (ADS)

van Geffen, S.; Duis, J.; Miller, R.

2008-04-01

Ever emerging applications in handheld multimedia devices such as mobile phones, laptop computers, portable video games and digital cameras requiring increased screen resolutions are driving higher aggregate bitrates between host processor and display(s) enabling services such as mobile video conferencing, video on demand and TV broadcasting. Larger displays and smaller phones require complex mechanical 3D hinge configurations striving to combine maximum functionality with compact building volumes. Conventional galvanic interconnections such as Micro-Coax and FPC carrying parallel digital data between host processor and display module may produce Electromagnetic Interference (EMI) and bandwidth limitations caused by small cable size and tight cable bends. To reduce the number of signals through a hinge, the mobile phone industry, organized in the MIPI (Mobile Industry Processor Interface) alliance, is currently defining an electrical interface transmitting serialized digital data at speeds >1Gbps. This interface allows for electrical or optical interconnects. Above 1Gbps optical links may offer a cost effective alternative because of their flexibility, increased bandwidth and immunity to EMI. This paper describes the development of optical links for handheld communication devices. A cable assembly based on a special Plastic Optical Fiber (POF) selected for its mechanical durability is terminated with a small form factor molded lens assembly which interfaces between an 850nm VCSEL transmitter and a receiving device on the printed circuit board of the display module. A statistical approach based on a Lean Design For Six Sigma (LDFSS) roadmap for new product development tries to find an optimum link definition which will be robust and low cost meeting the power consumption requirements appropriate for battery operated systems.

Fast Low-Cost Multiple Sensor Readout System

DOEpatents

Carter-Lewis, David; Krennich, Frank; Le Bohec, Stephane; Petry, Dirk; Sleege, Gary

2004-04-06

A low resolution data acquisition system is presented. The data acquisition system has a plurality of readout modules serially connected to a controller. Each readout module has a FPGA in communication with analog to digital (A/D) converters, which are connected to sensors. The A/D converter has eight bit or lower resolution. The FPGA detects when a command is addressed to it and commands the A/D converters to convert analog sensor data into digital data. The digital data is sent on a high speed serial communication bus to the controller. A graphical display is used in one embodiment to indicate if a sensor reading is outside of a predetermined range.

The Belle II Pixel Detector Data Acquisition and Background Suppression System

NASA Astrophysics Data System (ADS)

Lautenbach, K.; Deschamps, B.; Dingfelder, J.; Getzkow, D.; Geßler, T.; Konorov, I.; Kühn, W.; Lange, S.; Levit, D.; Liu, Z.-A.; Marinas, C.; Münchow, D.; Rabusov, A.; Reiter, S.; Spruck, B.; Wessel, C.; Zhao, J.

2017-06-01

The Belle II experiment at the future SuperKEKB collider in Tsukuba, Japan, features a design luminosity of 8 · 1035 cm-2s-1, which is a factor of 40 larger than that of its predecessor Belle. The pixel detector (PXD) with about 8 million pixels is based on the DEPFET technology and will improve the vertex resolution in beam direction by a factor of 2. With an estimated trigger rate of 30 kHz, the PXD is expected to generate a data rate of 20 GBytes/s, which is about 10 times larger than the amount of data generated by all other Belle II subdetectors. Due to the large beam-related background, the PXD requires a data acquisition system with high-bandwidth data links and realtime background reduction by a factor of 30. To achieve this, the Belle II pixel DAQ uses an FPGA-based computing platform with high speed serial links implemented in the ATCA (Advanced Telecommunications Computing Architecture) standard. The architecture and performance of the data acquisition system and data reduction of the PXD will be presented. In April 2016 and February 2017 a prototype PXD-DAQ system operated in a test beam campaign delivered data with the whole readout chain under realistic high rate conditions. Final results from the beam test will be presented.

40 CFR 86.1242-90 - Records required.

Code of Federal Regulations, 2012 CFR

2012-07-01

... maximum power rating and rated speed; Fuel system (including number of carburetors, number of carburetor barrels, fuel injection type, fuel tank(s) capacity and location, and number and size (volume and working... serial number, a reference to a vehicle test cell number may be used, provided the test cell records show...

40 CFR 86.1242-90 - Records required.

Code of Federal Regulations, 2013 CFR

2013-07-01

... maximum power rating and rated speed; Fuel system (including number of carburetors, number of carburetor barrels, fuel injection type, fuel tank(s) capacity and location, and number and size (volume and working... serial number, a reference to a vehicle test cell number may be used, provided the test cell records show...

40 CFR 86.1242-90 - Records required.

Code of Federal Regulations, 2011 CFR

2011-07-01

... maximum power rating and rated speed; Fuel system (including number of carburetors, number of carburetor barrels, fuel injection type, fuel tank(s) capacity and location, and number and size (volume and working... serial number, a reference to a vehicle test cell number may be used, provided the test cell records show...

40 CFR 86.1242-90 - Records required.

Code of Federal Regulations, 2010 CFR

2010-07-01

... maximum power rating and rated speed; Fuel system (including number of carburetors, number of carburetor barrels, fuel injection type, fuel tank(s) capacity and location, and number and size (volume and working... serial number, a reference to a vehicle test cell number may be used, provided the test cell records show...

40 CFR Appendix I to Part 204 - Appendix I to Part 204

Code of Federal Regulations, 2011 CFR

2011-07-01

... Part 204 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Pt. 204, App. I Appendix I to Part 204 Table I... Noise Data Sheet Test report number: Subject: Manufacturer: Model: Serial No.: Rated speed: Rpm: Rated...

40 CFR Appendix I to Part 204 - Appendix I to Part 204

Code of Federal Regulations, 2010 CFR

2010-07-01

... Part 204 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Pt. 204, App. I Appendix I to Part 204 Table I... Noise Data Sheet Test report number: Subject: Manufacturer: Model: Serial No.: Rated speed: Rpm: Rated...

Direct kinematics solution architectures for industrial robot manipulators: Bit-serial versus parallel

NASA Astrophysics Data System (ADS)

Lee, J.; Kim, K.

A Very Large Scale Integration (VLSI) architecture for robot direct kinematic computation suitable for industrial robot manipulators was investigated. The Denavit-Hartenberg transformations are reviewed to exploit a proper processing element, namely an augmented CORDIC. Specifically, two distinct implementations are elaborated on, such as the bit-serial and parallel. Performance of each scheme is analyzed with respect to the time to compute one location of the end-effector of a 6-links manipulator, and the number of transistors required.

Direct kinematics solution architectures for industrial robot manipulators: Bit-serial versus parallel

NASA Technical Reports Server (NTRS)

Lee, J.; Kim, K.

1991-01-01

A Very Large Scale Integration (VLSI) architecture for robot direct kinematic computation suitable for industrial robot manipulators was investigated. The Denavit-Hartenberg transformations are reviewed to exploit a proper processing element, namely an augmented CORDIC. Specifically, two distinct implementations are elaborated on, such as the bit-serial and parallel. Performance of each scheme is analyzed with respect to the time to compute one location of the end-effector of a 6-links manipulator, and the number of transistors required.

Word frequency effects in immediate serial recall of pure and mixed lists: tests of the associative link hypothesis.

PubMed

Saint-Aubin, Jean; LeBlanc, Jacinthe

2005-12-01

In immediate serial recall, high-frequency words are better recalled than low-frequency words. Recently, it has been suggested that high-frequency words are better recalled because of their better long-term associative links, and not because of the intrinsic properties of their long-term representations. In the experiment reported here, recall performance was compared for pure lists of high- and low-frequency words, and for mixed lists composed of either one low- and five high-frequency words or the reverse. The usual advantage of high-frequency words was found with pure lists and this advantage was reduced, but still significant with mixed lists composed of five low-frequency words. However, the low-frequency word included in a high-frequency list was recalled just as well as high-frequency words. Results are challenging for the associative link hypothesis and are best interpreted within an item-based reconstruction hypothesis, along with a distinctiveness account.

Ways to estimate speeds for the purposes of air quality conformity analyses.

DOT National Transportation Integrated Search

2002-01-01

A speed post-processor refers to equations or lookup tables that can determine vehicle speeds on a particular roadway link using only the limited information available in a long-range planning model. An estimated link speed is usually based on volume...

Frequency of the first feature in action sequences influences feature binding.

PubMed

Mattson, Paul S; Fournier, Lisa R; Behmer, Lawrence P

2012-10-01

We investigated whether binding among perception and action feature codes is a preliminary step toward creating a more durable memory trace of an action event. If so, increasing the frequency of a particular event (e.g., a stimulus requiring a movement with the left or right hand in an up or down direction) should increase the strength and speed of feature binding for this event. The results from two experiments, using a partial-repetition paradigm, confirmed that feature binding increased in strength and/or occurred earlier for a high-frequency (e.g., left hand moving up) than for a low-frequency (e.g., right hand moving down) event. Moreover, increasing the frequency of the first-specified feature in the action sequence alone (e.g., "left" hand) increased the strength and/or speed of action feature binding (e.g., between the "left" hand and movement in an "up" or "down" direction). The latter finding suggests an update to the theory of event coding, as not all features in the action sequence equally determine binding strength. We conclude that action planning involves serial binding of features in the order of action feature execution (i.e., associations among features are not bidirectional but are directional), which can lead to a more durable memory trace. This is consistent with physiological evidence suggesting that serial order is preserved in an action plan executed from memory and that the first feature in the action sequence may be critical in preserving this serial order.

Three-dimensional reconstruction from serial sections in PC-Windows platform by using 3D_Viewer.

PubMed

Xu, Yi-Hua; Lahvis, Garet; Edwards, Harlene; Pitot, Henry C

2004-11-01

Three-dimensional (3D) reconstruction from serial sections allows identification of objects of interest in 3D and clarifies the relationship among these objects. 3D_Viewer, developed in our laboratory for this purpose, has four major functions: image alignment, movie frame production, movie viewing, and shift-overlay image generation. Color images captured from serial sections were aligned; then the contours of objects of interest were highlighted in a semi-automatic manner. These 2D images were then automatically stacked at different viewing angles, and their composite images on a projected plane were recorded by an image transform-shift-overlay technique. These composition images are used in the object-rotation movie show. The design considerations of the program and the procedures used for 3D reconstruction from serial sections are described. This program, with a digital image-capture system, a semi-automatic contours highlight method, and an automatic image transform-shift-overlay technique, greatly speeds up the reconstruction process. Since images generated by 3D_Viewer are in a general graphic format, data sharing with others is easy. 3D_Viewer is written in MS Visual Basic 6, obtainable from our laboratory on request.

Conjugate-Gradient Algorithms For Dynamics Of Manipulators

NASA Technical Reports Server (NTRS)

Fijany, Amir; Scheid, Robert E.

1993-01-01

Algorithms for serial and parallel computation of forward dynamics of multiple-link robotic manipulators by conjugate-gradient method developed. Parallel algorithms have potential for speedup of computations on multiple linked, specialized processors implemented in very-large-scale integrated circuits. Such processors used to stimulate dynamics, possibly faster than in real time, for purposes of planning and control.

Speed, Accuracy, and Serial Order in Sequence Production

ERIC Educational Resources Information Center

Pfordresher, Peter Q.; Palmer, Caroline; Jungers, Melissa K.

2007-01-01

The production of complex sequences like music or speech requires the rapid and temporally precise production of events (e.g., notes and chords), often at fast rates. Memory retrieval in these circumstances may rely on the simultaneous activation of both the current event and the surrounding context (Lashley, 1951). We describe an extension to a…

Parallel Processing in Visual Search Asymmetry

ERIC Educational Resources Information Center

Dosher, Barbara Anne; Han, Songmei; Lu, Zhong-Lin

2004-01-01

The difficulty of visual search may depend on assignment of the same visual elements as targets and distractors-search asymmetry. Easy C-in-O searches and difficult O-in-C searches are often associated with parallel and serial search, respectively. Here, the time course of visual search was measured for both tasks with speed-accuracy methods. The…

A computational approach to real-time image processing for serial time-encoded amplified microscopy

NASA Astrophysics Data System (ADS)

Oikawa, Minoru; Hiyama, Daisuke; Hirayama, Ryuji; Hasegawa, Satoki; Endo, Yutaka; Sugie, Takahisa; Tsumura, Norimichi; Kuroshima, Mai; Maki, Masanori; Okada, Genki; Lei, Cheng; Ozeki, Yasuyuki; Goda, Keisuke; Shimobaba, Tomoyoshi

2016-03-01

High-speed imaging is an indispensable technique, particularly for identifying or analyzing fast-moving objects. The serial time-encoded amplified microscopy (STEAM) technique was proposed to enable us to capture images with a frame rate 1,000 times faster than using conventional methods such as CCD (charge-coupled device) cameras. The application of this high-speed STEAM imaging technique to a real-time system, such as flow cytometry for a cell-sorting system, requires successively processing a large number of captured images with high throughput in real time. We are now developing a high-speed flow cytometer system including a STEAM camera. In this paper, we describe our approach to processing these large amounts of image data in real time. We use an analog-to-digital converter that has up to 7.0G samples/s and 8-bit resolution for capturing the output voltage signal that involves grayscale images from the STEAM camera. Therefore the direct data output from the STEAM camera generates 7.0G byte/s continuously. We provided a field-programmable gate array (FPGA) device as a digital signal pre-processor for image reconstruction and finding objects in a microfluidic channel with high data rates in real time. We also utilized graphics processing unit (GPU) devices for accelerating the calculation speed of identification of the reconstructed images. We built our prototype system, which including a STEAM camera, a FPGA device and a GPU device, and evaluated its performance in real-time identification of small particles (beads), as virtual biological cells, owing through a microfluidic channel.

Discriminability and dimensionality effects in visual search for featural conjunctions: a functional pop-out.

PubMed

Dehaene, S

1989-07-01

Treisman and Gelade's (1980) feature-integration theory of attention states that a scene must be serially scanned before the objects in it can be accurately perceived. Is serial scanning compatible with the speed observed in the perception of real-world scenes? Most real scenes consist of many more dimensions (color, size, shape, depth, etc.) than those generally found in search paradigms. Furthermore, real objects differ from each other along many of these dimensions. The present experiment assessed the influence of the total number of dimensions and target/distractor discriminability (the number of dimensions that suffice to separate a target from distractors) on search times for a conjunction of features. Search was always found to be serial. However, for the most discriminable targets, search rate was so fast that search times were in the same range as pop-out detection times. Apparently, greater discriminability enables subjects to direct attention at a faster rate and at only a fraction of the items in a scene.

A comparative study of working memory: immediate serial spatial recall in baboons (Papio papio) and humans.

PubMed

Fagot, Joël; De Lillo, Carlo

2011-12-01

Two experiments assessed if non-human primates can be meaningfully compared to humans in a non-verbal test of serial recall. A procedure was used that was derived from variations of the Corsi test, designed to test the effects of sequence structure and movement path length in humans. Two baboons were tested in Experiment 1. The monkeys showed several attributes of human serial recall. These included an easier recall of sequences with a shorter number of items and of sequences characterized by a shorter path length when the number of items was kept constant. However, the accuracy and speed of processing did not indicate that the monkeys were able to benefit from the spatiotemporal structure of sequences. Humans tested in Experiment 2 showed a quantitatively longer memory span, and, in contrast with monkeys, benefitted from sequence structure. The results are discussed in relation to differences in how human and non-human primates segment complex visual patterns. Copyright © 2011 Elsevier Ltd. All rights reserved.

Longitudinal Evidence Linking Processing Speed to the Development of Reasoning

ERIC Educational Resources Information Center

Kail, Robert V.; Lervåg, Arne; Hulme, Charles

2016-01-01

Age-related change in processing speed has been linked directly to increases in reasoning as well as indirectly via increases in the capacity of working memory (WM). Most of the evidence linking change in speed to reasoning has come from cross-sectional research; in this article we present the findings from a 2½-year longitudinal study of 277 6-…

From brief gaps to very long pauses: temporal isolation does not benefit serial recall.

PubMed

Nimmo, Lisa M; Lewandowsky, Stephan

2005-12-01

Theoretical explanations of short-term memory for serial order can be classified on the basis of whether or not they invoke time as a causal variable. According to time-based accounts, such as temporal distinctiveness theories, there is an intimate link between time and memory. Event-based theories, by contrast, postulate processes such as interference or rehearsal to account for seemingly temporal phenomena in short-term memory. We report an experiment that examined whether extended temporal isolation benefits serial recall performance. Regardless of whether the participants were quiet or performed articulatory suppression during list presentation, temporal isolation did not benefit memory even if items were separated from their neighbors by up to 7 sec. These findings challenge time-based theories of short-term memory.

Impact of Aging on the Dynamics of Memory Retrieval: A Time-Course Analysis

ERIC Educational Resources Information Center

Oztekin, Ilke; Gungor, Nur Zeynep; Badre, David

2012-01-01

The response-signal speed-accuracy trade-off (SAT) procedure was used to provide an in-depth investigation of the impact of aging on the dynamics of short-term memory retrieval. Young and older adults studied sequentially presented 3-item lists, immediately followed by a recognition probe. Analyses of composite list and serial position SAT…

High speed, long distance, data transmission multiplexing circuit

DOEpatents

Mariotti, Razvan

1991-01-01

A high speed serial data transmission multiplexing circuit, which is operable to accurately transmit data over long distances (up to 3 Km), and to multiplex, select and continuously display real time analog signals in a bandwidth from DC to 100 Khz. The circuit is made fault tolerant by use of a programmable flywheel algorithm, which enables the circuit to tolerate one transmission error before losing synchronization of the transmitted frames of data. A method of encoding and framing captured and transmitted data is used which has a low overhead and prevents some particular transmitted data patterns from locking an included detector/decoder circuit.

Applications considerations in the system design of highly concurrent multiprocessors

NASA Technical Reports Server (NTRS)

Lundstrom, Stephen F.

1987-01-01

A flow model processor approach to parallel processing is described, using very-high-performance individual processors, high-speed circuit switched interconnection networks, and a high-speed synchronization capability to minimize the effect of the inherently serial portions of applications on performance. Design studies related to the determination of the number of processors, the memory organization, and the structure of the networks used to interconnect the processor and memory resources are discussed. Simulations indicate that applications centered on the large shared data memory should be able to sustain over 500 million floating point operations per second.

A rotor-mounted digital instrumentation system for helicopter blade flight research measurements

NASA Technical Reports Server (NTRS)

Knight, V. H., Jr.; Haywood, W. S., Jr.; Williams, M. L.

1978-01-01

A rotor mounted flight instrumentation system developed for helicopter rotor blade research is described. The system utilizes high speed digital techniques to acquire research data from miniature pressure transducers on advanced rotor airfoils which are flight tested on an AH-1G helicopter. The system employs microelectronic pulse code modulation (PCM) multiplexer digitizer stations located remotely on the blade and in a hub mounted metal canister. As many as 25 sensors can be remotely digitized by a 2.5 mm thick electronics package mounted on the blade near the tip to reduce blade wiring. The electronics contained in the canister digitizes up to 16 sensors, formats these data with serial PCM data from the remote stations, and transmits the data from the canister which is above the plane of the rotor. Data are transmitted over an RF link to the ground for real time monitoring and to the helicopter fuselage for tape recording. The complete system is powered by batteries located in the canister and requires no slip rings on the rotor shaft.

Front-end electronics development for TPC detector in the MPD/NICA project

NASA Astrophysics Data System (ADS)

Cheremukhina, G.; Movchan, S.; Vereschagin, S.; Zaporozhets, S.

2017-06-01

The article is aimed at describing the development status, measuring results and design changes of the TPC front-end electronics. The TPC is placed in the middle of Multi-Purpose Detector (MPD) and provides tracing and identifying of charged particles in the pseudorapidity range |η| < 1.2. The readout system is one of the most complex parts of the TPC. The electronics of each readout chamber is an independent system. The whole system contains 95232 channels, 1488 64-channel—front-end cards (FEC), 24 readout control units (RCU). The front-end electronics (FEE) is based on ASICs, FPGAs and high-speed serial links. The concept of the TPC front-end electronics has been motivated from one side—by the requirements concerning the NICA accelerator complex which will operate at the luminosity up to 1027 cm-2 s-1 for Au79+ ions over the energy range of 4 < √SNN < 11 GeV with the trigger rate up to 7 kHz and from the other side—by the requirements of the 4-π geometry to minimize the substance on the end-caps of the TPC.

Influence of serial electrical stimulations of perifornical and posterior hypothalamic orexin-containing neurons on regulation of sleep homeostasis and sleep-wakefulness cycle recovery from experimental comatose state and anesthesia-induced deep sleep.

PubMed

Chijavadze, E; Chkhartishvili, E; Babilodze, M; Maglakelidze, N; Nachkebia, N

2013-11-01

The work was aimed for the ascertainment of following question - whether Orexin-containing neurons of dorsal and lateral hypothalamic, and brain Orexinergic system in general, are those cellular targets which can speed up recovery of disturbed sleep homeostasis and accelerate restoration of sleep-wakefulness cycle phases during some pathological conditions - experimental comatose state and/or deep anesthesia-induced sleep. Study was carried out on white rats. Modeling of experimental comatose state was made by midbrain cytotoxic lesions at intra-collicular level.Animals were under artificial respiration and special care. Different doses of Sodium Ethaminal were used for deep anesthesia. 30 min after comatose state and/or deep anesthesia induced sleep serial electrical stimulations of posterior and/or perifornical hypothalamus were started. Stimulation period lasted for 1 hour with the 5 min intervals between subsequent stimulations applied by turn to the left and right side hypothalamic parts.EEG registration of cortical and hippocampal electrical activity was started immediately after experimental comatose state and deep anesthesia induced sleep and continued continuously during 72 hour. According to obtained new evidences, serial electrical stimulations of posterior and perifornical hypothalamic Orexin-containing neurons significantly accelerate recovery of sleep homeostasis, disturbed because of comatose state and/or deep anesthesia induced sleep. Speed up recovery of sleep homeostasis was manifested in acceleration of coming out from comatose state and deep anesthesia induced sleep and significant early restoration of sleep-wakefulness cycle behavioral states.

Software development kit for a compact cryo-refrigerator

NASA Astrophysics Data System (ADS)

Gardiner, J.; Hamilton, J.; Lawton, J.; Knight, K.; Wilson, A.; Spagna, S.

2017-12-01

This paper introduces a Software Development Kit (SDK) that enables the creation of custom software applications that automate the control of a cryo-refrigerator (Quantum Design model GA-1) in third party instruments. A remote interface allows real time tracking and logging of critical system diagnostics such as pressures, temperatures, valve states and run modes. The helium compressor scroll capsule speed and Gifford-McMahon (G-M) cold head speed can be manually adjusted over a serial communication line via a CAN interface. This configuration optimizes cooling power, while reducing wear on moving components thus extending service life. Additionally, a proportional speed control mode allows for automated throttling of speeds based on temperature or pressure feedback from a 3rd party device. Warm up and cool down modes allow 1st and 2nd stage temperatures to be adjusted without the use of external heaters.

Universal Reconfigurable Translator Module (URTM) Final Report

NASA Technical Reports Server (NTRS)

Leventhal, Edward; Machan, Roman; Jones, Rob

2009-01-01

This report describes the Universal Reconfigurable Translation Module, or URTM. The URTM was developed by Sigma Space Corporation for NASA in order to translate specific serial protocols, both logically and physically. At present, the prototype configuration has targeted MIL-STD-1553B (RT and BC), IEEE 1394b (Firewire), and ECSS-E-50-12A (SpaceWire). The objectives of this program were to study the feasibility of a configurable URTM to translate serial link data as might be used in a space-flight mission and to design, develop, document, and deliver an engineering prototype model of the URTM with a path to spaceflight. By simply connecting two of the three Physical Interface Modules (PIM) on either end of the RPTM (Reconfigurable Protocol Translator Module), the URTM then self configures via a library of interface translation functions, thereby allowing the two data links to communicate seamlessly.

High rate data acquisition from Spacelab/Shuttle

NASA Technical Reports Server (NTRS)

Coffey, R.

1978-01-01

The need for high data rates from a variety of experiments on Spacelab/Shuttle produced the requirement for the Spacelab High Rate Multiplexer/Demultiplexer system. This system acquires serial digital data at asynchronous bit rates from up to sixteen experiments, two data buses, three voice links, two tape recorders, and a universal time channel. Experiment data rates may vary from 200 bps to 16 Mbps while recorded data rates range from 250 Kbps to 32 Mbps. The High Rate Multiplexer (HRM) accepts these data inputs and forms a serial PCM output at flexible rates up to 48 Mbps. This PCM output is transmitted to ground by a Ku-Band RF link via the Tracking and Data Relay Satellite System (TDRSS) or recorded on board for delayed transmission. A complementary ground based High Rate Demultiplexer (HRDM) accepts and demultiplexes the composite PCM data at ground processing locations.

Bit-error-rate testing of fiber optic data links for MMIC-based phased array antennas

NASA Technical Reports Server (NTRS)

Shalkhauser, K. A.; Kunath, R. R.; Daryoush, A. S.

1990-01-01

The measured bit-error-rate (BER) performance of a fiber optic data link to be used in satellite communications systems is presented and discussed. In the testing, the link was measured for its ability to carry high burst rate, serial-minimum shift keyed (SMSK) digital data similar to those used in actual space communications systems. The fiber optic data link, as part of a dual-segment injection-locked RF fiber optic link system, offers a means to distribute these signals to the many radiating elements of a phased array antenna. Test procedures, experimental arrangements, and test results are presented.

Mild traumatic brain injury and suicide risk among a clinical sample of deployed military personnel: Evidence for a serial mediation model of anger and depression.

PubMed

Stanley, Ian H; Joiner, Thomas E; Bryan, Craig J

2017-01-01

Research has demonstrated a robust link between traumatic brain injuries (TBIs) and suicide risk. Yet, few studies have investigated factors that account for this link. Utilizing a clinical sample of deployed military personnel, this study aimed to examine a serial meditation model of anger and depression in the association of mild TBI and suicide risk. A total of 149 military service members referred for evaluation/treatment of a suspected head injury at a military hospital participated in the present study (92.6% male; M age  = 27.9y). Self-report measures included the Suicidal Behaviors Questionnaire-Revised (SBQ-R), Automated Neuropsychological Assessment Metrics (ANAM) anger and depression subscales, and Behavioral Health Measure-20 depression subscale. A current mild TBI diagnosis was confirmed by a licensed clinical psychologist/physician. Overall, 84.6% (126/149) of participants met diagnostic criteria for a current mild TBI. Bootstrapped serial mediation analyses indicated that the association of mild TBI and suicide risk is serially mediated by anger and depression symptoms (bias-corrected 95% confidence interval [CI] for the indirect effect = 0.044, 0.576). An alternate serial mediation model in which depression symptoms precede anger was not statistically significant (bias-corrected 95% CI for the indirect effect = -0.405, 0.050). Among a clinical sample of military personnel, increased anger and depression statistically mediated the association of mild TBI and suicide risk, and anger appears to precede depression in this pathway. Findings suggest that therapeutically targeting anger may serve to thwart the trajectory to suicide risk among military personnel who experience a mild TBI. Future research should investigate this conjecture within a prospective design to establish temporality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Speech Timing and Verbal Short-Term Memory: Evidence for Contrasting Deficits in Down Syndrome and Williams Syndrome

ERIC Educational Resources Information Center

Jarrold, Christopher; Cowan, Nelson; Hewes, Alexa K.; Riby, Deborah M.

2004-01-01

This study explored the degree of verbal short-term memory deficit among individuals with Down syndrome and Williams syndrome, and the extent to which any such impairment could be accounted for by a relative slowing of rehearsal and output processes. Measures of serial recall and detailed assessments of speeded articulation for short and long…

E-2889

NASA Image and Video Library

1953-08-04

A 1953 photo of some of the research aircraft at the NACA High-Speed Flight Research Station (now known as the the Dryden Flight Research Center). The photo shows the X-3 (center) and, clockwise from left: X-1A (Air Force serial number 48-1384), the third D-558-1 (NACA tail number 142), XF-92A, X-5, D-558-2, and X-4.

Word-length effect in verbal short-term memory in individuals with Down's syndrome.

PubMed

Kanno, K; Ikeda, Y

2002-11-01

Many studies have indicated that individuals with Down's syndrome (DS) show a specific deficit in short-term memory for verbal information. The aim of the present study was to investigate the influence of the length of words on verbal short-term memory in individuals with DS. Twenty-eight children with DS and 10 control participants matched for memory span were tested on verbal serial recall and speech rate, which are thought to involve rehearsal and output speed. Although a significant word-length effect was observed in both groups for the recall of a larger number of items with a shorter spoken duration than for those with a longer spoken duration, the number of correct recalls in the group with DS was reduced compared to the control subjects. The results demonstrating poor short-term memory in children with DS were irrelevant to speech rate. In addition, the proportion of repetition-gained errors in serial recall was higher in children with DS than in control subjects. The present findings suggest that poor access to long-term lexical knowledge, rather than overt articulation speed, constrains verbal short-term memory functions in individuals with DS.

Parallel peak pruning for scalable SMP contour tree computation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carr, Hamish A.; Weber, Gunther H.; Sewell, Christopher M.

As data sets grow to exascale, automated data analysis and visualisation are increasingly important, to intermediate human understanding and to reduce demands on disk storage via in situ analysis. Trends in architecture of high performance computing systems necessitate analysis algorithms to make effective use of combinations of massively multicore and distributed systems. One of the principal analytic tools is the contour tree, which analyses relationships between contours to identify features of more than local importance. Unfortunately, the predominant algorithms for computing the contour tree are explicitly serial, and founded on serial metaphors, which has limited the scalability of this formmore » of analysis. While there is some work on distributed contour tree computation, and separately on hybrid GPU-CPU computation, there is no efficient algorithm with strong formal guarantees on performance allied with fast practical performance. Here in this paper, we report the first shared SMP algorithm for fully parallel contour tree computation, withfor-mal guarantees of O(lgnlgt) parallel steps and O(n lgn) work, and implementations with up to 10x parallel speed up in OpenMP and up to 50x speed up in NVIDIA Thrust.« less

Modern Speed-Reading Apps Do Not Foster Reading Comprehension.

PubMed

Acklin, Dina; Papesh, Megan H

2017-01-01

New computer apps are gaining popularity by suggesting that reading speeds can be drastically increased when eye movements that normally occur during reading are eliminated. This is done using rapid serial visual presentation (RSVP), where words are presented 1 at a time, thus preventing natural eye movements such as saccades, fixations, and regressions from occurring. Al- though the companies producing these apps suggest that RSVP reading does not yield comprehension deficits, research investigating the role of eye movements in reading documents shows the necessity of natural eye movements for accurate comprehension. The current study explored variables that may affect reading comprehension during RSVP reading, including text difficulty (6th grade and 12th grade), text presentation speed (static, 700 wpm, and 1,000 wpm), and working memory capacity (WMC). Consistent with recent work showing a tenuous relationship between comprehension and WMC, participants' WMC did not predict comprehension scores. Instead, comprehension was most affected by reading speed: Static text was associated with superior performance, relative to either RSVP reading condition. Furthermore, slower RSVP speeds yielded better verbatim comprehension, and faster speeds benefited inferential comprehension.

Who is talking in backward crosstalk? Disentangling response- from goal-conflict in dual-task performance.

PubMed

Janczyk, Markus; Pfister, Roland; Hommel, Bernhard; Kunde, Wilfried

2014-07-01

Responses in the second of two subsequently performed tasks can speed up compatible responses in the temporally preceding first task. Such backward crosstalk effects (BCEs) represent a challenge to the assumption of serial processing in stage models of human information processing, because they indicate that certain features of the second response have to be represented before the first response is emitted. Which of these features are actually relevant for BCEs is an open question, even though identifying these features is important for understanding the nature of parallel and serial response selection processes in dual-task performance. Motivated by effect-based models of action control, we show in three experiments that the BCE to a considerable degree reflects features of intended action effects, although features of the response proper (or response-associated kinesthetic feedback) also seem to play a role. These findings suggest that the codes of action effects (or action goals) can become activated simultaneously rather than serially, thereby creating BCEs. Copyright © 2014 Elsevier B.V. All rights reserved.

On the reduced-complexity of LDPC decoders for ultra-high-speed optical transmission.

PubMed

Djordjevic, Ivan B; Xu, Lei; Wang, Ting

2010-10-25

We propose two reduced-complexity (RC) LDPC decoders, which can be used in combination with large-girth LDPC codes to enable ultra-high-speed serial optical transmission. We show that optimally attenuated RC min-sum sum algorithm performs only 0.46 dB (at BER of 10(-9)) worse than conventional sum-product algorithm, while having lower storage memory requirements and much lower latency. We further study the use of RC LDPC decoding algorithms in multilevel coded modulation with coherent detection and show that with RC decoding algorithms we can achieve the net coding gain larger than 11 dB at BERs below 10(-9).

High-speed optical feeder-link system using adaptive optics

NASA Astrophysics Data System (ADS)

Arimoto, Yoshinori; Hayano, Yutaka; Klaus, Werner

1997-05-01

We propose a satellite laser communication system between a ground station and a geostationary satellite, named high- speed optical feeder link system. It is based on the application of (a) high-speed optical devices, which have been developed for ground-based high-speed fiber-optic communications, and (b) the adaptive optics which compensates wavefront distortions due to atmospheric turbulences using a real time feedback control. A link budget study shows that a system with 10-Gbps bit-rate are available assuming the state-of-the-art device performance of the Er-doped fiber amplifier. We further discuss preliminary measurement results of the atmospheric turbulence at the telescope site in Tokyo, and present current study on the design of the key components for the feeder-link laser transceiver.

Assessment of processing speed in children with mild TBI: a "first look" at the validity of pediatric ImPACT.

PubMed

Newman, Julie B; Reesman, Jennifer H; Vaughan, Christopher G; Gioia, Gerard A

2013-01-01

Deficit in the speed of cognitive processing is a commonly identified neuropsychological change in children recovering from a mild TBI. However, there are few validated child assessment instruments that allow for serial assessment over the course of recovery in this population. Pediatric ImPACT is a novel measure that purports to assess cognitive speed, learning, and efficiency in this population. The current study sought to validate the use of this new measure by comparing it to traditional paper and pencil measures of processing speed. One hundred and sixty-four children (71% male) age 5-12 with mild TBI evaluated in an outpatient concussion clinic were administered Pediatric ImPACT and other neuropsychological test measures as part of a flexible test battery. Performance on the Response Speed Composite of Pediatric ImPACT was more strongly associated with other measures of cognitive processing speed, than with measures of immediate/working memory and learning/memory in this sample of injured children. There is preliminary support for convergent and discriminant validity of Pediatric ImPACT as a measure for use in post-concussion evaluations of processing speed in children.

Nostalgia-Evoked Inspiration: Mediating Mechanisms and Motivational Implications.

PubMed

Stephan, Elena; Sedikides, Constantine; Wildschut, Tim; Cheung, Wing-Yee; Routledge, Clay; Arndt, Jamie

2015-10-01

Six studies examined the nostalgia-inspiration link and its motivational implications. In Study 1, nostalgia proneness was positively associated with inspiration frequency and intensity. In Studies 2 and 3, the recollection of nostalgic (vs. ordinary) experiences increased both general inspiration and specific inspiration to engage in exploratory activities. In Study 4, serial mediational analyses supported a model in which nostalgia increases social connectedness, which subsequently fosters self-esteem, which then boosts inspiration. In Study 5, a rigorous evaluation of this serial mediational model (with a novel nostalgia induction controlling for positive affect) reinforced the idea that nostalgia-elicited social connectedness increases self-esteem, which then heightens inspiration. Study 6 extended the serial mediational model by demonstrating that nostalgia-evoked inspiration predicts goal pursuit (intentions to pursue an important goal). Nostalgia spawns inspiration via social connectedness and attendant self-esteem. In turn, nostalgia-evoked inspiration bolsters motivation. © 2015 by the Society for Personality and Social Psychology, Inc.

The Effects of Stimulus Presentation Rate on the Short-Term Memory of Learning Disabled Children.

ERIC Educational Resources Information Center

Tarver, Sara G.; Ellsworth, Patricia S.

To test the hypothesis that the developmental lag in verbal rehearsal which has been documented for the learning disabled is due to a naming speed deficit (i.e., slow retrieval of stimulus names), the serial recall performance of 64 learning disabled children at four grade levels (1, 3, 5, and 7) was compared under three stimulus presentation…

High-Speed Systolic Array Testbed.

DTIC Science & Technology

1987-10-01

applications since the concept was introduced by H.T. Kung In 1978. This highly parallel architecture of nearet neighbor data communciation and...must be addressed. For instance, should bit-serial or bit parallei computation be utilized. Does the dynamic range of the candidate applications or...numericai stability of the algorithms used require computations In fixed point and Integer format or the architecturally more complex and slower floating

Data acquisition in a high-speed rotating frame for New Mexico Institute of Mining and Technology liquid sodium αω dynamo experiment.

PubMed

Si, Jiahe; Colgate, Stirling A; Li, Hui; Martinic, Joe; Westpfahl, David

2013-10-01

New Mexico Institute of Mining and Technology liquid sodium αω-dynamo experiment models the magnetic field generation in the universe as discussed in detail by Colgate, Li, and Pariev [Phys. Plasmas 8, 2425 (2001)]. To obtain a quasi-laminar flow with magnetic Reynolds number R(m) ~ 120, the dynamo experiment consists of two co-axial cylinders of 30.5 cm and 61 cm in diameter spinning up to 70 Hz and 17.5 Hz, respectively. During the experiment, the temperature of the cylinders must be maintained to 110 °C to ensure that the sodium remains fluid. This presents a challenge to implement a data acquisition (DAQ) system in such high temperature, high-speed rotating frame, in which the sensors (including 18 Hall sensors, 5 pressure sensors, and 5 temperature sensors, etc.) are under the centrifugal acceleration up to 376g. In addition, the data must be transmitted and stored in a computer 100 ft away for safety. The analog signals are digitized, converted to serial signals by an analog-to-digital converter and a field-programmable gate array. Power is provided through brush/ring sets. The serial signals are sent through ring/shoe sets capacitively, then reshaped with cross-talk noises removed. A microcontroller-based interface circuit is used to decode the serial signals and communicate with the data acquisition computer. The DAQ accommodates pressure up to 1000 psi, temperature up to more than 130 °C, and magnetic field up to 1000 G. First physics results have been analyzed and published. The next stage of the αω-dynamo experiment includes the DAQ system upgrade.

Imaging mouse cerebellum with serial optical coherence scanner (Conference Presentation)

NASA Astrophysics Data System (ADS)

Liu, Chao J.; Williams, Kristen; Orr, Harry; Taner, Akkin

2017-02-01

We present the serial optical coherence scanner (SOCS), which consists of a polarization sensitive optical coherence tomography and a vibratome with associated controls for serial imaging, to visualize the cerebellum and adjacent brainstem of mouse. The cerebellar cortical layers and white matter are distinguished by using intrinsic optical contrasts. Images from serial scans reveal the large-scale anatomy in detail and map the nerve fiber pathways in the cerebellum and adjacent brainstem. The optical system, which has 5.5 μm axial resolution, utilizes a scan lens or a water-immersion microscope objective resulting in 10 μm or 4 μm lateral resolution, respectively. The large-scale brain imaging at high resolution requires an efficient way to collect large datasets. It is important to improve the SOCS system to deal with large-scale and large number of samples in a reasonable time. The imaging and slicing procedure for a section took about 4 minutes due to a low speed of the vibratome blade to maintain slicing quality. SOCS has potential to investigate pathological changes and monitor the effects of therapeutic drugs in cerebellar diseases such as spinocerebellar ataxia 1 (SCA1). The SCA1 is a neurodegenerative disease characterized by atrophy and eventual loss of Purkinje cells from the cerebellar cortex, and the optical contrasts provided by SOCS is being evaluated for biomarkers of the disease.

Reliability analysis of degradable networks with modified BPR

NASA Astrophysics Data System (ADS)

Wang, Yu-Qing; Zhou, Chao-Fan; Jia, Bin; Zhu, Hua-Bing

2017-12-01

In this paper, the effect of the speed limit on degradable networks with capacity restrictions and the forced flow is investigated. The link performance function considering the road capacity is proposed. Additionally, the probability density distribution and the cumulative distribution of link travel time are introduced in the degradable network. By the mean of distinguishing the value of the speed limit, four cases are discussed, respectively. Means and variances of link travel time and route one of the degradable road network are calculated. Besides, by the mean of performing numerical simulation experiments in a specific network, it is found that the speed limit strategy can reduce the travel time budget and mean travel time of link and route. Moreover, it reveals that the speed limit strategy can cut down variances of the travel time of networks to some extent.

Embedded system of image storage based on fiber channel

NASA Astrophysics Data System (ADS)

Chen, Xiaodong; Su, Wanxin; Xing, Zhongbao; Wang, Hualong

2008-03-01

In domains of aerospace, aviation, aiming, and optic measure etc., the embedded system of imaging, processing and recording is absolutely necessary, which has small volume, high processing speed and high resolution. But the embedded storage technology becomes system bottleneck because of developing slowly. It is used to use RAID to promote storage speed, but it is unsuitable for the embedded system because of its big volume. Fiber channel (FC) technology offers a new method to develop the high-speed, portable storage system. In order to make storage subsystem meet the needs of high storage rate, make use of powerful Virtex-4 FPGA and high speed fiber channel, advance a project of embedded system of digital image storage based on Xilinx Fiber Channel Arbitrated Loop LogiCORE. This project utilizes Virtex- 4 RocketIO MGT transceivers to transmit the data serially, and connects many Fiber Channel hard drivers by using of Arbitrated Loop optionally. It can achieve 400MBps storage rate, breaks through the bottleneck of PCI interface, and has excellences of high-speed, real-time, portable and massive capacity.

Comparative study of indirect immunofluorescence, enzyme-linked immunosorbent assay, and the Tzanck smear test for the diagnosis of pemphigus.

PubMed

Zhou, Tingting; Fang, Siyue; Li, Chunlei; Hua, Hong

2016-11-01

Pemphigus is one of the potentially fatal autoimmune blistering diseases. An early and accurate diagnosis is important for prognosis and therapy. It may be difficult to diagnosis based on clinical grounds alone. Direct and indirect immunofluorescence, enzyme-linked immunosorbent assay, the Tzanck smear test, or histopathology are all available for the diagnosis of pemphigus. However, there are no generally accepted diagnostic criteria for the diagnosis of this condition at present. To evaluate the diagnostic value of indirect immunofluorescence, enzyme-linked immunosorbent assay, and the Tzanck smear test for the diagnosis of pemphigus in dental clinics. A single-center retrospective study was conducted, and the clinical data of 33 patients with pemphigus and 61 controls were collected and analyzed from the Department of Oral Medicine, Peking University School of Stomatology, during 2010-2014. The sensitivities and specificities of indirect immunofluorescence, enzyme-linked immunosorbent assay, and the Tzanck smear test were calculated and compared in two groups. Sensitivities for the Tzanck smear test, indirect immunofluorescence, and enzyme-linked immunosorbent assay were 96.7%, 84.8%, and 84.8%, respectively, whereas the specificities of these tests were 60%, 91.8%, and 96.7%, respectively. The serial tests for the Tzanck smear test and enzyme-linked immunosorbent assay showed 82% sensitivity and 98.7% specificity. The serial test for the Tzanck smear test and enzyme-linked immunosorbent assay may represent a simple, rapid, and reliable way to definitive diagnosis of pemphigus. It is recommended as a common test for the diagnosis of pemphigus in dental clinics. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Data Processing Aspects of MEDLARS

PubMed Central

Austin, Charles J.

1964-01-01

The speed and volume requirements of MEDLARS necessitate the use of high-speed data processing equipment, including paper-tape typewriters, a digital computer, and a special device for producing photo-composed output. Input to the system is of three types: variable source data, including citations from the literature and search requests; changes to such master files as the medical subject headings list and the journal record file; and operating instructions such as computer programs and procedures for machine operators. MEDLARS builds two major stores of data on magnetic tape. The Processed Citation File includes bibliographic citations in expanded form for high-quality printing at periodic intervals. The Compressed Citation File is a coded, time-sequential citation store which is used for high-speed searching against demand request input. Major design considerations include converting variable-length, alphanumeric data to mechanical form quickly and accurately; serial searching by the computer within a reasonable period of time; high-speed printing that must be of graphic quality; and efficient maintenance of various complex computer files. PMID:14119287

DATA PROCESSING ASPECTS OF MEDLARS.

PubMed

AUSTIN, C J

1964-01-01

The speed and volume requirements of MEDLARS necessitate the use of high-speed data processing equipment, including paper-tape typewriters, a digital computer, and a special device for producing photo-composed output. Input to the system is of three types: variable source data, including citations from the literature and search requests; changes to such master files as the medical subject headings list and the journal record file; and operating instructions such as computer programs and procedures for machine operators. MEDLARS builds two major stores of data on magnetic tape. The Processed Citation File includes bibliographic citations in expanded form for high-quality printing at periodic intervals. The Compressed Citation File is a coded, time-sequential citation store which is used for high-speed searching against demand request input. Major design considerations include converting variable-length, alphanumeric data to mechanical form quickly and accurately; serial searching by the computer within a reasonable period of time; high-speed printing that must be of graphic quality; and efficient maintenance of various complex computer files.

Control model design to limit DC-link voltage during grid fault in a dfig variable speed wind turbine

NASA Astrophysics Data System (ADS)

Nwosu, Cajethan M.; Ogbuka, Cosmas U.; Oti, Stephen E.

2017-08-01

This paper presents a control model design capable of inhibiting the phenomenal rise in the DC-link voltage during grid- fault condition in a variable speed wind turbine. Against the use of power circuit protection strategies with inherent limitations in fault ride-through capability, a control circuit algorithm capable of limiting the DC-link voltage rise which in turn bears dynamics that has direct influence on the characteristics of the rotor voltage especially during grid faults is here proposed. The model results so obtained compare favorably with the simulation results as obtained in a MATLAB/SIMULINK environment. The generated model may therefore be used to predict near accurately the nature of DC-link voltage variations during fault given some factors which include speed and speed mode of operation, the value of damping resistor relative to half the product of inner loop current control bandwidth and the filter inductance.

Increasing the resource of high load compression springs

NASA Astrophysics Data System (ADS)

Zemlyanushnova, N. Y.; Zemlyanushnov, N. A.

2017-10-01

Valve springs of VAZ automobiles’ engines are manufactured by using a new method. The decrease of dispersion of operating load in experimental springs compared to serial ones has been proved. The springs have passed a stress cycling test. With the new method having been used, it has been proved that the resource of high load springs working at high loading speed with coils collision has increased up to 60%.

Method and apparatus for data sampling

DOEpatents

Odell, Daniel M. C.

1994-01-01

A method and apparatus for sampling radiation detector outputs and determining event data from the collected samples. The method uses high speed sampling of the detector output, the conversion of the samples to digital values, and the discrimination of the digital values so that digital values representing detected events are determined. The high speed sampling and digital conversion is performed by an A/D sampler that samples the detector output at a rate high enough to produce numerous digital samples for each detected event. The digital discrimination identifies those digital samples that are not representative of detected events. The sampling and discrimination also provides for temporary or permanent storage, either serially or in parallel, to a digital storage medium.

Spectral-element simulation of two-dimensional elastic wave propagation in fully heterogeneous media on a GPU cluster

NASA Astrophysics Data System (ADS)

Rudianto, Indra; Sudarmaji

2018-04-01

We present an implementation of the spectral-element method for simulation of two-dimensional elastic wave propagation in fully heterogeneous media. We have incorporated most of realistic geological features in the model, including surface topography, curved layer interfaces, and 2-D wave-speed heterogeneity. To accommodate such complexity, we use an unstructured quadrilateral meshing technique. Simulation was performed on a GPU cluster, which consists of 24 core processors Intel Xeon CPU and 4 NVIDIA Quadro graphics cards using CUDA and MPI implementation. We speed up the computation by a factor of about 5 compared to MPI only, and by a factor of about 40 compared to Serial implementation.

Fine motor movements while drawing during the encoding phase of a serial verbal recall task reduce working memory performance.

PubMed

Tindle, Richard; Longstaff, Mitchell G

2016-02-01

The time-based resource-sharing (TBRS) model of working memory indicates that secondary tasks that capture attention for relatively long periods can result in the interference of working memory processing and maintenance. The current study investigates if discrete and continuous movements have differing effects on a concurrent, verbal serial recall task. In the listening condition, participants were asked to recall spoken words presented in lists of six. In the drawing conditions, participants performed the same task while producing discrete (star) or continuous (circle) movements. As hypothesised, participants recalled more words overall in the listening condition compared to the combined drawing conditions. The prediction that the continuous movement condition would reduce recall compared to listening was also supported. Fine-grained analysis at each serial position revealed significantly more words were recalled at mid serial positions in the listening condition, with worst recall for the continuous condition at position 5 compared to the listening and discrete conditions. Kinematic analysis showed that participants increased the size and speed of the continuous movements resulting in a similar duration and number of strokes for each condition. The duration of brief pauses in the discrete condition was associated with the number of words recalled. The results indicate that fine motor movements reduced working memory performance; however, it was not merely performing a movement but the type of the movement that determined how resources were diverted. In the context of the TBRS, continuous movements could be capturing attention for longer periods relative to discrete movements, reducing verbal serial recall. Copyright © 2016 Elsevier B.V. All rights reserved.

Frequency-agile wireless sensor networks

NASA Astrophysics Data System (ADS)

Arms, Steven W.; Townsend, Christopher P.; Churchill, David L.; Hamel, Michael J.; Galbreath, Jacob H.; Mundell, Steven W.

2004-07-01

Our goal was to demonstrate a wireless communications system capable of simultaneous, high speed data communications from a variety of sensors. We have previously reported on the design and application of 2 KHz data logging transceiver nodes, however, only one node may stream data at a time, since all nodes on the network use the same communications frequency. To overcome these limitations, second generation data logging transceivers were developed with software programmable radio frequency (RF) communications. Each node contains on-board memory (2 Mbytes), sensor excitation, instrumentation amplifiers with programmable gains & offsets, multiplexer, 16 bit A/D converter, microcontroller, and frequency agile, bi-directional, frequency shift keyed (FSK) RF serial data link. These systems are capable of continuous data transmission from 26 distinct nodes (902-928 MHz band, 75 kbaud). The system was demonstrated in a compelling structural monitoring application. The National Parks Service requested a means for continual monitoring and recording of sensor data from the Liberty Bell during a move to a new location (Philadelphia, October 2003). Three distinct, frequency agile, wireless sensing nodes were used to detect visible crack shear/opening micromotions, triaxial accelerations, and hairline crack tip strains. The wireless sensors proved to be useful in protecting the Liberty Bell.

An exploratory analysis linking neuropsychological testing to quantification of tractography using High Definition Fiber Tracking (HDFT) in military TBI.

PubMed

Presson, Nora; Beers, Sue R; Morrow, Lisa; Wagener, Lauren M; Bird, William A; Van Eman, Gina; Krishnaswamy, Deepa; Penderville, Joshua; Borrasso, Allison J; Benso, Steven; Puccio, Ava; Fissell, Catherine; Okonkwo, David O; Schneider, Walter

2015-09-01

To realize the potential value of tractography in traumatic brain injury (TBI), we must identify metrics that provide meaningful information about functional outcomes. The current study explores quantitative metrics describing the spatial properties of tractography from advanced diffusion imaging (High Definition Fiber Tracking, HDFT). In a small number of right-handed males from military TBI (N = 7) and civilian control (N = 6) samples, both tract homologue symmetry and tract spread (proportion of brain mask voxels contacted) differed for several tracts among civilian controls and extreme groups in the TBI sample (high scorers and low scorers) for verbal recall, serial reaction time, processing speed index, and trail-making. Notably, proportion of voxels contacted in the arcuate fasciculus distinguished high and low performers on the CVLT-II and PSI, potentially reflecting linguistic task demands, and GFA in the left corticospinal tract distinguished high and low performers in PSI and Trail Making Test Part A, potentially reflecting right hand motor response demands. The results suggest that, for advanced diffusion imaging, spatial properties of tractography may add analytic value to measures of tract anisotropy.

Have You Got What It Takes...And Are You Using All You Could?

ERIC Educational Resources Information Center

Dyer, Hilary

1994-01-01

Suggests ways of using personal computers in special libraries, including online searching; CD-ROM networks; reference work; current awareness services; press cuttings services; selective dissemination of information; local databases; object linking and embedding; cataloging; acquisitions; circulation; serials control; interlibrary loan; space…

Towards green high capacity optical networks

NASA Astrophysics Data System (ADS)

Glesk, I.; Mohd Warip, M. N.; Idris, S. K.; Osadola, T. B.; Andonovic, I.

2011-09-01

The demand for fast, secure, energy efficient high capacity networks is growing. It is fuelled by transmission bandwidth needs which will support among other things the rapid penetration of multimedia applications empowering smart consumer electronics and E-businesses. All the above trigger unparallel needs for networking solutions which must offer not only high-speed low-cost "on demand" mobile connectivity but should be ecologically friendly and have low carbon footprint. The first answer to address the bandwidth needs was deployment of fibre optic technologies into transport networks. After this it became quickly obvious that the inferior electronic bandwidth (if compared to optical fiber) will further keep its upper hand on maximum implementable serial data rates. A new solution was found by introducing parallelism into data transport in the form of Wavelength Division Multiplexing (WDM) which has helped dramatically to improve aggregate throughput of optical networks. However with these advancements a new bottleneck has emerged at fibre endpoints where data routers must process the incoming and outgoing traffic. Here, even with the massive and power hungry electronic parallelism routers today (still relying upon bandwidth limiting electronics) do not offer needed processing speeds networks demands. In this paper we will discuss some novel unconventional approaches to address network scalability leading to energy savings via advance optical signal processing. We will also investigate energy savings based on advanced network management through nodes hibernation proposed for Optical IP networks. The hibernation reduces the network overall power consumption by forming virtual network reconfigurations through selective nodes groupings and by links segmentations and partitionings.

A working memory account of the interaction between numbers and spatial attention.

PubMed

van Dijck, Jean-Philippe; Abrahamse, Elger L; Acar, Freya; Ketels, Boris; Fias, Wim

2014-01-01

Rather than reflecting the long-term memory construct of a mental number line, it has been proposed that the relation between numbers and space is of a more temporary nature and constructed in working memory during task execution. In three experiments we further explored the viability of this working memory account. Participants performed a speeded dot detection task with dots appearing left or right, while maintaining digits or letters in working memory. Just before presentation of the dot, these digits or letters were used as central cues. These experiments show that the "attentional SNARC-effect" (where SNARC is the spatial-numerical association of response codes) is not observed when only the lastly perceived number cue--and no serially ordered sequence of cues--is maintained in working memory (Experiment 1). It is only when multiple items (numbers in Experiment 2; letters in Experiment 3) are stored in working memory in a serially organized way that the attentional cueing effect is observed as a function of serial working memory position. These observations suggest that the "attentional SNARC-effect" is strongly working memory based. Implications for theories on the mental representation of numbers are discussed.

Delineating the contribution of long-term associations to immediate recall.

PubMed

Saint-Aubin, Jean; Guérard, Katherine; Chamberland, Cindy; Malenfant, Amélie

2014-01-01

In the present study we examined the contribution of semantic associative links to short-term recall performance by using the separation effect first introduced in free recall studies (Glanzer, 1969). Pairs of associated words were inserted in the to-be-remembered lists. In two experiments associated words were better recalled than non-associated words, and were better recalled when they were adjacent in the list than when they were separated by one non-associated item. In addition results showed that forward associative links among pair members were as beneficial to immediate serial recall as backward associative links. Finally the benefit of associative links among pair members was observed with both forward and backward recall.

Drill drive mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dressel, M.O.

1979-10-30

A drill drive mechanism is especially adapted to provide both rotational drive and axial feed for a drill of substantial diameter such as may be used for drilling holes for roof bolts in mine shafts. The drill shaft is made with a helical pattern of scroll-like projections on its surface for removal of cuttings. The drill drive mechanism includes a plurality of sprockets carrying two chains of drive links which are arranged to interlock around the drill shaft with each drive link having depressions which mate with the scroll-like projections. As the chain links move upwardly or downwardly the surfacesmore » of the depressions in the links mate with the scroll projections to move the shaft axially. Tangs on the drive links mate with notch surfaces between scroll projections to provide a means for rotating the shaft. Projections on the drive links mate together at the center to hold the drive links tightly around the drill shaft. The entire chain drive mechanism is rotated around the drill shaft axis by means of a hydraulic motor and gear drive to cause rotation of the drill shaft. This gear drive also connects with a differential gearset which is interconnected with a second gear. A second motor is connected to the spider shaft of the different gearset to produce differential movement (speeds) at the output gears of the differential gearset. This differential in speed is utilized to drive said second gear at a speed different from the speed of said gear drive, this speed differential being utilized to drive said sprockets for axial movement of said drill shaft. 11 claims.« less

Drill drive mechanism

DOEpatents

Dressel, Michael O.

1979-01-01

A drill drive mechanism is especially adapted to provide both rotational drive and axial feed for a drill of substantial diameter such as may be used for drilling holes for roof bolts in mine shafts. The drill shaft is made with a helical pattern of scroll-like projections on its surface for removal of cuttings. The drill drive mechanism includes a plurality of sprockets carrying two chains of drive links which are arranged to interlock around the drill shaft with each drive link having depressions which mate with the scroll-like projections. As the chain links move upwardly or downwardly the surfaces of the depressions in the links mate with the scroll projections to move the shaft axially. Tangs on the drive links mate with notch surfaces between scroll projections to provide a means for rotating the shaft. Projections on the drive links mate together at the center to hold the drive links tightly around the drill shaft. The entire chain drive mechanism is rotated around the drill shaft axis by means of a hydraulic motor and gear drive to cause rotation of the drill shaft. This gear drive also connects with a differential gearset which is interconnected with a second gear. A second motor is connected to the spider shaft of the differential gearset to produce differential movement (speeds) at the output gears of the differential gearset. This differential in speed is utilized to drive said second gear at a speed different from the speed of said gear drive, this speed differential being utilized to drive said sprockets for axial movement of said drill shaft.

The Link between Text Difficulty, Reading Speed and Exploration of Printed Text during Shared Book Reading

ERIC Educational Resources Information Center

Roy-Charland, Annie; Perron, Melanie; Turgeon, Krystle-Lee; Hoffman, Nichola; Chamberland, Justin A.

2016-01-01

In the current study the reading speed of the narration and the difficulty of the text was manipulated and links were explored with children's attention to the printed text in shared book reading. Thirty-nine children (24 grade 1 and 15 grade 2) were presented easy and difficult books at slow (syllable by syllable) or fast (adult reading speed)…

Performance evaluation of multiple (32 channels) sub-nanosecond TDC implemented in low-cost FPGA

NASA Astrophysics Data System (ADS)

Lichard, P.; Konstantinou, G.; Villar Vilanueva, A.; Palladino, V.

2014-03-01

NA62 experiment Straw tracker frontend board serves as a gas-tight detector cover and integrates two CARIOCA chips, a low cost FPGA (Cyclon III, Altera) and a set of 400Mbit/s links to the backend. The FPGA houses 16 pairs of sub-nanosecond resolution TDCs with derandomizers and an output link serializer. Evaluation methods, including simulations, and performance results of the system in the lab and on a detector prototype are presented.

Field validation of speed estimation techniques for air quality conformity analysis.

DOT National Transportation Integrated Search

2004-01-01

The air quality conformity analysis process requires the estimation of speeds for a horizon year on a link-by-link basis where only a few future roadway characteristics, such as forecast volume and capacity, are known. Accordingly, the Virginia Depar...

F-15A in flight closeup of 10 degree cone experiment

NASA Image and Video Library

1976-02-04

The number two F-15A (Serial #71-0281) was obtained by NASA from the U.S. Air Force in 1976 and was used for more than 25 advanced research projects involving aerodynamics, performance, propulsion control, control integration, instrumentation development, human factors, and flight test techniques. Included in these projects was its role as a testbed to evaluate aerodynamic pressures on Space Shuttle thermal protection tiles at specific altitudes and speeds.

New method for designing serial resonant power converters

NASA Astrophysics Data System (ADS)

Hinov, Nikolay

2017-12-01

In current work is presented one comprehensive method for design of serial resonant energy converters. The method is based on new simplified approach in analysis of such kind power electronic devices. It is grounded on supposing resonant mode of operation when finding relation between input and output voltage regardless of other operational modes (when controlling frequency is below or above resonant frequency). This approach is named `quasiresonant method of analysis', because it is based on assuming that all operational modes are `sort of' resonant modes. An estimation of error was made because of the a.m. hypothesis and is compared to the classic analysis. The `quasiresonant method' of analysis gains two main advantages: speed and easiness in designing of presented power circuits. Hence it is very useful in practice and in teaching Power Electronics. Its applicability is proven with mathematic modelling and computer simulation.

A novel brain-computer interface based on the rapid serial visual presentation paradigm.

PubMed

Acqualagna, Laura; Treder, Matthias Sebastian; Schreuder, Martijn; Blankertz, Benjamin

2010-01-01

Most present-day visual brain computer interfaces (BCIs) suffer from the fact that they rely on eye movements, are slow-paced, or feature a small vocabulary. As a potential remedy, we explored a novel BCI paradigm consisting of a central rapid serial visual presentation (RSVP) of the stimuli. It has a large vocabulary and realizes a BCI system based on covert non-spatial selective visual attention. In an offline study, eight participants were presented sequences of rapid bursts of symbols. Two different speeds and two different color conditions were investigated. Robust early visual and P300 components were elicited time-locked to the presentation of the target. Offline classification revealed a mean accuracy of up to 90% for selecting the correct symbol out of 30 possibilities. The results suggest that RSVP-BCI is a promising new paradigm, also for patients with oculomotor impairments.

Method and apparatus for data sampling

DOEpatents

Odell, D.M.C.

1994-04-19

A method and apparatus for sampling radiation detector outputs and determining event data from the collected samples is described. The method uses high speed sampling of the detector output, the conversion of the samples to digital values, and the discrimination of the digital values so that digital values representing detected events are determined. The high speed sampling and digital conversion is performed by an A/D sampler that samples the detector output at a rate high enough to produce numerous digital samples for each detected event. The digital discrimination identifies those digital samples that are not representative of detected events. The sampling and discrimination also provides for temporary or permanent storage, either serially or in parallel, to a digital storage medium. 6 figures.

Theory of Visual Attention (TVA) applied to mice in the 5-choice serial reaction time task.

PubMed

Fitzpatrick, C M; Caballero-Puntiverio, M; Gether, U; Habekost, T; Bundesen, C; Vangkilde, S; Woldbye, D P D; Andreasen, J T; Petersen, A

2017-03-01

The 5-choice serial reaction time task (5-CSRTT) is widely used to measure rodent attentional functions. In humans, many attention studies in healthy and clinical populations have used testing based on Bundesen's Theory of Visual Attention (TVA) to estimate visual processing speeds and other parameters of attentional capacity. We aimed to bridge these research fields by modifying the 5-CSRTT's design and by mathematically modelling data to derive attentional parameters analogous to human TVA-based measures. C57BL/6 mice were tested in two 1-h sessions on consecutive days with a version of the 5-CSRTT where stimulus duration (SD) probe length was varied based on information from previous TVA studies. Thereafter, a scopolamine hydrobromide (HBr; 0.125 or 0.25 mg/kg) pharmacological challenge was undertaken, using a Latin square design. Mean score values were modelled using a new three-parameter version of TVA to obtain estimates of visual processing speeds, visual thresholds and motor response baselines in each mouse. The parameter estimates for each animal were reliable across sessions, showing that the data were stable enough to support analysis on an individual level. Scopolamine HBr dose-dependently reduced 5-CSRTT attentional performance while also increasing reward collection latency at the highest dose. Upon TVA modelling, scopolamine HBr significantly reduced visual processing speed at both doses, while having less pronounced effects on visual thresholds and motor response baselines. This study shows for the first time how 5-CSRTT performance in mice can be mathematically modelled to yield estimates of attentional capacity that are directly comparable to estimates from human studies.

Cognitive functioning over 2 years after intracerebral hemorrhage in school-aged children.

PubMed

Murphy, Lexa K; Compas, Bruce E; Gindville, Melissa C; Reeslund, Kristen L; Jordan, Lori C

2017-11-01

Previous research investigating outcomes after pediatric intracerebral hemorrhage (ICH) has generally been limited to global and sensorimotor outcomes. This study examined cognitive outcomes after spontaneous ICH in school-aged children with serial assessments over 2 years after stroke. Seven children (age range 6-16y, median 13; six males, one female; 57% white, 43% black) presenting with spontaneous ICH (six arteriovenous malformations) were assessed at 3 months, 12 months, and 24 months after stroke. The Pediatric Stroke Outcome Measure (PSOM) quantified neurological outcome and Wechsler Intelligence Scales measured cognitive outcomes: verbal comprehension, perceptual reasoning, working memory, and processing speed. PSOM scales showed improved neurological function over the first 12 months, with mild to no sensorimotor deficits and moderate overall deficits at 1- and 2-year follow-ups (median 2-year sensorimotor PSOM=0.5, total PSOM=1.5). Changes in cognitive function indicated a different trajectory; verbal comprehension and perceptual reasoning improved over 24 months; low performance was sustained in processing speed and working memory. Age-normed centile scores decreased between 1- and 2-year follow-ups for working memory, suggesting emerging deficits compared with peers. Early and serial cognitive testing in children with ICH is needed to assess cognitive functioning and support children in school as they age and cognitive deficits become more apparent and important for function. In children with intracerebral hemorrhage (ICH), motor function improved between 3 months and 24 months. Improvements in cognitive function were variable between 3 months and 24 months. Working memory centiles declined, suggesting emerging deficits compared with peers. Processing speed improved but remained significantly below the 50th centile. Cognitive impact of ICH may increase with age in children. © 2017 Mac Keith Press.

Effects of visual span on reading speed and parafoveal processing in eye movements during sentence reading.

PubMed

Risse, Sarah

2014-07-15

The visual span (or ‘‘uncrowded window’’), which limits the sensory information on each fixation, has been shown to determine reading speed in tasks involving rapid serial visual presentation of single words. The present study investigated whether this is also true for fixation durations during sentence reading when all words are presented at the same time and parafoveal preview of words prior to fixation typically reduces later word-recognition times. If so, a larger visual span may allow more efficient parafoveal processing and thus faster reading. In order to test this hypothesis, visual span profiles (VSPs) were collected from 60 participants and related to data from an eye-tracking reading experiment. The results confirmed a positive relationship between the readers’ VSPs and fixation-based reading speed. However, this relationship was not determined by parafoveal processing. There was no evidence that individual differences in VSPs predicted differences in parafoveal preview benefit. Nevertheless, preview benefit correlated with reading speed, suggesting an independent effect on oculomotor control during reading. In summary, the present results indicate a more complex relationship between the visual span, parafoveal processing, and reading speed than initially assumed. © 2014 ARVO.

Providing Geographic Datasets as Linked Data in Sdi

NASA Astrophysics Data System (ADS)

Hietanen, E.; Lehto, L.; Latvala, P.

2016-06-01

In this study, a prototype service to provide data from Web Feature Service (WFS) as linked data is implemented. At first, persistent and unique Uniform Resource Identifiers (URI) are created to all spatial objects in the dataset. The objects are available from those URIs in Resource Description Framework (RDF) data format. Next, a Web Ontology Language (OWL) ontology is created to describe the dataset information content using the Open Geospatial Consortium's (OGC) GeoSPARQL vocabulary. The existing data model is modified in order to take into account the linked data principles. The implemented service produces an HTTP response dynamically. The data for the response is first fetched from existing WFS. Then the Geographic Markup Language (GML) format output of the WFS is transformed on-the-fly to the RDF format. Content Negotiation is used to serve the data in different RDF serialization formats. This solution facilitates the use of a dataset in different applications without replicating the whole dataset. In addition, individual spatial objects in the dataset can be referred with URIs. Furthermore, the needed information content of the objects can be easily extracted from the RDF serializations available from those URIs. A solution for linking data objects to the dataset URI is also introduced by using the Vocabulary of Interlinked Datasets (VoID). The dataset is divided to the subsets and each subset is given its persistent and unique URI. This enables the whole dataset to be explored with a web browser and all individual objects to be indexed by search engines.

Biological variation of the natriuretic peptides and their role in monitoring patients with heart failure.

PubMed

Wu, Alan H B; Smith, Andrew

2004-03-15

B-type natriuretic peptide (BNP) and the inactive metabolite NT-proBNP are proven tests for diagnosis and staging of severity for patients with heart failure. However, the utility of these biomarkers for monitoring the success of drug therapy remains to be determined. Results of longitudinal studies on serial blood testing must be linked to overall patient morbidity and mortality outcomes. We previously determined the 8-week biological variability (BV) of BNP and NT-proBNP assays in healthy subjects and the 1-day BV for BNP alone in patients with compensated and stable heart failure. From these studies, the percent statistical change in serial samples of approximately 100% difference was estimated (95% confidence). We applied the biological variability concepts to the serial results of BNP and NT-proBNP collected from patients with heart failure and compared the performance of these two markers. While there are minor differences in the results between the assays from one time period to another, the overall interpretation of results are essentially identical. Moreover, the majority of individual serial time points are not significantly different from the previous value. Frequent testing (e.g. daily) for BNP and NT-proBNP to monitor therapy for patients with CHF is not indicated, as overall changes require several days to become evident.

Working memory in children assessed with serial chaining and Simon tasks.

PubMed

Parrish, Audrey E; Perdue, Bonnie M; Kelly, Andrew J; Beran, Michael J

2018-06-06

In the serial chaining task, participants are required to produce a sequence of responses to stimuli in the correct order, and sometimes must determine the sequence at trial outset if stimuli are masked after the first response is made. Similarly, the Simon memory span task presents a participant with a sequence of colors, and the participant must recreate the sequence after the full series is shown. In efforts to directly link the comparative literature on sequential planning behavior and working memory span with the developmental literature, we presented preschool children with the serial chaining task using masked Arabic numerals (N = 44) and the Simon memory span task (N = 65). Older children outperformed younger children in each task, sequencing a longer string of numbers in the serial chaining task and remembering a greater number of items in the Simon task. Controlling for the role of age, there was a significant positive relationship between task scores. These results highlight the emergence of working memory skills that might underlie planning capacities in children using a task developed for nonhuman animals, and the results indicate that improvement in general executive functions could be measured using either or both of these tasks among human children and nonhuman species. Copyright © 2018 Elsevier B.V. All rights reserved.

The influence of serial repitching of Saccharomyces pastorianus on its karyotype and protein profile during the fermentation of gluten-free buckwheat and quinoa wort.

PubMed

Deželak, Matjaž; Gebremariam, Mekonnen M; Cadež, Neža; Zupan, Jure; Raspor, Peter; Zarnkow, Martin; Becker, Thomas; Košir, Iztok Jože

2014-08-18

Gluten-free beer-like beverages from malted buckwheat and quinoa are somehow close to their commercial production, but rather high expenses are expected due to the relatively high price of grain, some technological adaptations of process and the need for external enzyme supplementation during mashing. One of the common and efficient cost reduction measures in the industrial scale is serial repitching of the yeast biomass, which has not been studied for the buckwheat and quinoa wort fermentation before. In that manner we have monitored possible changes in yeast's proteins and chromosomal DNA during eleven serial repitchings of the yeast Saccharomyces pastorianus strain TUM 34/70 for fermentation of the barley, buckwheat and quinoa wort. Karyotypes showed changes in regard to the raw materials used and many responsible candidate proteins are suggested which could cause these differences. Different relative expressions of some protein bands were also linked to the proteins involved in yeast stress response and proteins involved in fermentation performance. Results suggest that serial repitching of the strain TUM 34/70 seems suitable for the production of gluten-free beer-like beverages from buckwheat and quinoa. Copyright © 2014 Elsevier B.V. All rights reserved.

Evolution of sprint speed in African savannah herbivores in relation to predation.

PubMed

Bro-Jørgensen, Jakob

2013-11-01

Predator-prey arms races are widely speculated to underlie fast speed in terrestrial mammals. However, due to lack of empirical testing, both the specificity of any evolutionary coupling between particular predator and prey species, and the relevance of alternative food-based hypotheses of speed evolution, remain obscure. Here I examine the ecological links between the sprint speed of African savannah herbivores, their vulnerability to predators, and their diet. I show that sprint speed is strongly predicted by the vulnerability of prey to their main predators; however, the direction of the link depends on the hunting style of the predator. Speed increases with vulnerability to pursuit predators, whereas vulnerability to ambush predators is associated with particularly slow speed. These findings suggest that differential vulnerability to specific predators can indeed drive interspecific variation in speed within prey communities, but that predator hunting style influences the intensity and consistency with which selection on speed is coupled between particular species. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Clothing resultant thermal insulation determined on a movable thermal manikin. Part I: effects of wind and body movement on total insulation.

PubMed

Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Shi, Wen; Zhang, Chengjiao

2015-10-01

In this serial study, 486 thermal manikin tests were carried out to examine the effects of air velocity and walking speed on both total and local clothing thermal insulations. Seventeen clothing ensembles with different layers (i.e., one, two, or three layers) were selected for the study. Three different wind speeds (0.15, 1.55, 4.0 m/s) and three levels of walking speed (0, 0.75, 1.2 m/s) were chosen. Thus, there are totally nine different testing conditions. The clothing total insulation and local clothing insulation at different body parts under those nine conditions were determined. In part I, empirical equations for estimating total resultant clothing insulation as a function of the static thermal insulation, relative air velocity, and walking speed were developed. In part II, the local thermal insulation of various garments was analyzed and correction equations on local resultant insulation for each body part were developed. This study provides critical database for potential applications in thermal comfort study, modeling of human thermal strain, and functional clothing design and engineering.

Massively Parallel Rogue Cell Detection Using Serial Time-Encoded Amplified Microscopy of Inertially Ordered Cells in High-Throughput Flow

DTIC Science & Technology

2012-08-01

techniques and STEAM imager. It couples the high-speed capability of the STEAM imager and differential phase contrast imaging of DIC / Nomarski microscopy...On 10 TPE chips, we obtained 9 homogenous and strong bonds, the failed bond being due to operator error and presence of air bubbles in the TPE...instruments, structural dynamics, and microelectromechanical systems (MEMS) via laser-scanning surface vibrometry , and observation of biomechanical motility

Measurement Techniques for Transmit Source Clock Jitter for Weak Serial RF Links

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin A.; Schlesinger, Adam M.

2010-01-01

Techniques for filtering clock jitter measurements are developed, in the context of controlling data modulation jitter on an RF carrier to accommodate low signal-to-noise ratio thresholds of high-performance error correction codes. Measurement artifacts from sampling are considered, and a tutorial on interpretation of direct readings is included.

78 FR 56592 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-13

... Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Helicopters AGENCY: Federal Aviation...) 76-12- 07 for all Bell Model 204B and certain serial-numbered Model 205A-1 helicopters with a certain... detect a crack in the link segments and, for affected Model 205A-1 helicopters, replacing the chain and...

78 FR 18228 - Airworthiness Directives; Agusta S.p.A. Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... occurred, either replacing it with an airworthy link assembly with a ``T'' marked after the serial number, or inspecting it for the torsion value force of the ball bearing before further flight. If no... assembly for the torsion value force of the ball bearing rotation within 5 hours time-in-service. If the...

Magnet measurement interfacing to the G-64 Euro standard bus and testing G-64 modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogrefe, R.L.

1995-07-01

The Magnet Measurement system utilizes various modules with a G-64 Euro (Gespac) Standard Interface. All modules are designed to be software controlled, normally under the constraints of the OS-9 operating system with all data transfers to a host computer accomplished by a serial link.

Distinctiveness as a function of spatial expansion in verbal working memory: comment on Kreitz, Furley, Memmert, and Simons (2015).

PubMed

Guida, Alessandro; van Dijck, Jean-Philippe; Abrahamse, Elger

2017-05-01

In a recent study, Kreitz et al. (Psychological Research 79:1034-1041, 2015) reported on a relationship between verbal working memory capacity and visuo-spatial attentional breadth. The authors hinted at attentional control to be the major link underlying this relationship. We put forward an alternative explanation by framing it within the context of a recent theory on serial order in memory: verbal item sequences entering in working memory are coded by adding a spatial context that can be derived from reading/writing habits. The observation by Kreitz et al. (Psychological Research 79:1034-1041, 2015) enriches this framework by suggesting that a larger visuo-spatial attentional breadth allows for internal coding of the verbal items in a more (spatially) distinct manner-thereby increasing working memory performance. As such, Kreitz et al. (Psychological Research 79:1034-1041, 2015) is the first study revealing a functional link between visuo-spatial attentional breadth and verbal working memory size, which strengthens spatial accounts of serial order coding in working memory.

Signaling cascades modulate the speed of signal propagation through space.

PubMed

Govern, Christopher C; Chakraborty, Arup K

2009-01-01

Cells are not mixed bags of signaling molecules. As a consequence, signals must travel from their origin to distal locations. Much is understood about the purely diffusive propagation of signals through space. Many signals, however, propagate via signaling cascades. Here, we show that, depending on their kinetics, cascades speed up or slow down the propagation of signals through space, relative to pure diffusion. We modeled simple cascades operating under different limits of Michaelis-Menten kinetics using deterministic reaction-diffusion equations. Cascades operating far from enzyme saturation speed up signal propagation; the second mobile species moves more quickly than the first through space, on average. The enhanced speed is due to more efficient serial activation of a downstream signaling module (by the signaling molecule immediately upstream in the cascade) at points distal from the signaling origin, compared to locations closer to the source. Conversely, cascades operating under saturated kinetics, which exhibit zero-order ultrasensitivity, can slow down signals, ultimately localizing them to regions around the origin. Signal speed modulation may be a fundamental function of cascades, affecting the ability of signals to penetrate within a cell, to cross-react with other signals, and to activate distant targets. In particular, enhanced speeds provide a way to increase signal penetration into a cell without needing to flood the cell with large numbers of active signaling molecules; conversely, diminished speeds in zero-order ultrasensitive cascades facilitate strong, but localized, signaling.

Neuropsychological profile and social cognition in congenital central hypoventilation syndrome (CCHS): Correlation with neuroimaging in a clinical case.

PubMed

Esteso Orduña, Borja; Seijas Gómez, Raquel; García Esparza, Elena; Briceño, Emily M; Melero Llorente, Javier; Fournier Del Castillo, María de la Concepción

2018-02-01

Congenital central hypoventilation syndrome (CCHS) is a rare genetic disorder due to paired-like homeobox gene (PHOX2B) mutations. CCHS patients suffer from dysregulation of the autonomic nervous system characterized by the absence of or extremely reduced response to hypercapnia and hypoxia, with neuropsychological deficits. The aim of this exploratory study is to describe the longitudinal neuropsychological profile and its correlations with magnetic resonance imaging (MRI) of a child with CCHS with a PHOX2B mutation. A comprehensive neuropsychological evaluation was conducted serially at age 7 years 4 months and 10 years 3 months, including assessment of intellectual functioning (IQ), motor functioning, perception, attention, executive functions, language, memory, social cognition, academic skills, and psychopathology. Reliable change index (RCI) scores were used to assess changes between assessments. We collected spin lattice relaxation time (T1)-weighted, fluid-attenuated inversion recovery (FLAIR), and spin spin lattice relaxation time (T2)-weighted images from the child at age 10 years 3 months using a 1.5-tesla MRI scanner. IQ, processing speed index (PSI), social cognition (theory of mind and facial emotion recognition), selective attention, naming, academic skills (reading/comprehension), and manual speed with right hand declined in the second evaluation relative to the initial evaluation, while visuoconstructional praxis, receptive vocabulary, working memory, and arithmetic skill improved. The patient showed a remarkable global deterioration in executive functions (planning, task flexibility, behavioral regulation, and metacognition) as revealed by parental report and clinical evaluation. MRI revealed gliosis from the head to tail of the hippocampus and thinning of parahippocampal gyri. In a clinical case of CCHS, serial evaluation revealed deterioration of executive functions and social cognition over a 3-year interval. These changes corresponded to hippocampal damage as revealed in MRI, which may have affected social cognition through its role in the default mode network. Serial neuropsychological assessment is clinically useful in managing the needs of these patients.

The contribution of discrete-trial naming and visual recognition to rapid automatized naming deficits of dyslexic children with and without a history of language delay

PubMed Central

Gasperini, Filippo; Brizzolara, Daniela; Cristofani, Paola; Casalini, Claudia; Chilosi, Anna Maria

2014-01-01

Children with Developmental Dyslexia (DD) are impaired in Rapid Automatized Naming (RAN) tasks, where subjects are asked to name arrays of high frequency items as quickly as possible. However the reasons why RAN speed discriminates DD from typical readers are not yet fully understood. Our study was aimed to identify some of the cognitive mechanisms underlying RAN-reading relationship by comparing one group of 32 children with DD with an age-matched control group of typical readers on a naming and a visual recognition task both using a discrete-trial methodology, in addition to a serial RAN task, all using the same stimuli (digits and colors). Results showed a significant slowness of DD children in both serial and discrete-trial naming (DN) tasks regardless of type of stimulus, but no difference between the two groups on the discrete-trial recognition task. Significant differences between DD and control participants in the RAN task disappeared when performance in the DN task was partialled out by covariance analysis for colors, but not for digits. The same pattern held in a subgroup of DD subjects with a history of early language delay (LD). By contrast, in a subsample of DD children without LD the RAN deficit was specific for digits and disappeared after slowness in DN was partialled out. Slowness in DN was more evident for LD than for noLD DD children. Overall, our results confirm previous evidence indicating a name-retrieval deficit as a cognitive impairment underlying RAN slowness in DD children. This deficit seems to be more marked in DD children with previous LD. Moreover, additional cognitive deficits specifically associated with serial RAN tasks have to be taken into account when explaining deficient RAN speed of these latter children. We suggest that partially different cognitive dysfunctions underpin superficially similar RAN impairments in different subgroups of DD subjects. PMID:25237301

Definition, analysis and development of an optical data distribution network for integrated avionics and control systems

NASA Technical Reports Server (NTRS)

Burns, R. R.

1981-01-01

The potential and functional requirements of fiber optic bus designs for next generation aircraft are assessed. State-of-the-art component evaluations and projections were used in the system study. Complex networks were decomposed into dedicated structures, star buses, and serial buses for detailed analysis. Comparisons of dedicated links, star buses, and serial buses with and without full duplex operation and with considerations for terminal to terminal communication requirements were obtained. This baseline was then used to consider potential extensions of busing methods to include wavelength multiplexing and optical switches. Example buses were illustrated for various areas of the aircraft as potential starting points for more detail analysis as the platform becomes definitized.

FELIX: The new detector readout system for the ATLAS experiment

NASA Astrophysics Data System (ADS)

Ryu, Soo; ATLAS TDAQ Collaboration

2017-10-01

After the Phase-I upgrades (2019) of the ATLAS experiment, the Front-End Link eXchange (FELIX) system will be the interface between the data acquisition system and the detector front-end and trigger electronics. FELIX will function as a router between custom serial links and a commodity switch network using standard technologies (Ethernet or Infiniband) to communicate with commercial data collecting and processing components. The system architecture of FELIX will be described and the status of the firmware implementation and hardware development currently in progress will be presented.

Stabilizing Health Monitoring for Wireless Sensor Networks

DTIC Science & Technology

2006-02-01

tation on a heterogenous WSN testbed, Kansei, comprising hundreds of Motes (of multiple types, specifically XSMs and TMoteSkys), Stargates , and PCs...0s; serial link between Stargates and XSMs, 0s; XSM radio, 5s, where higher delay corresponds to higher link cost. From the base station to a given...XSM X0 there can be many potential paths, including B-E-SG0-S-X0 and B-E-SG1-S-X1-R-X0, where B is base, SG is a Stargate , X is an XSM, E is Ethernet, S

Link and Network Layers Design for Ultra-High-Speed Terahertz-Band Communications Networks

DTIC Science & Technology

2017-01-01

throughput, and identify the optimal parameter values for their design (Sec. 6.2.3). Moreover, we validate and test the scheme with experimental data obtained...LINK AND NETWORK LAYERS DESIGN FOR ULTRA-HIGH- SPEED TERAHERTZ-BAND COMMUNICATIONS NETWORKS STATE UNIVERSITY OF NEW YORK (SUNY) AT BUFFALO JANUARY...TYPE FINAL TECHNICAL REPORT 3. DATES COVERED (From - To) FEB 2015 – SEP 2016 4. TITLE AND SUBTITLE LINK AND NETWORK LAYERS DESIGN FOR ULTRA-HIGH

Digit-color synaesthesia only enhances memory for colors in a specific context: A new method of duration thresholds to measure serial recall.

PubMed

Teichmann, A Lina; Nieuwenstein, Mark R; Rich, Anina N

2017-08-01

For digit-color synaesthetes, digits elicit vivid experiences of color that are highly consistent for each individual. The conscious experience of synaesthesia is typically unidirectional: Digits evoke colors but not vice versa. There is an ongoing debate about whether synaesthetes have a memory advantage over non-synaesthetes. One key question in this debate is whether synaesthetes have a general superiority or whether any benefit is specific to a certain type of material. Here, we focus on immediate serial recall and ask digit-color synaesthetes and controls to memorize digit and color sequences. We developed a sensitive staircase method manipulating presentation duration to measure participants' serial recall of both overlearned and novel sequences. Our results show that synaesthetes can activate digit information to enhance serial memory for color sequences. When color sequences corresponded to ascending or descending digit sequences, synaesthetes encoded these sequences at a faster rate than their non-synaesthetes counterparts and faster than non-structured color sequences. However, encoding color sequences is approximately 200 ms slower than encoding digit sequences directly, independent of group and condition, which shows that the translation process is time consuming. These results suggest memory advantages in synaesthesia require a modified dual-coding account, in which secondary (synaesthetically linked) information is useful only if it is more memorable than the primary information to be recalled. Our study further shows that duration thresholds are a sensitive method to measure subtle differences in serial recall performance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Investigation into response characteristics of the chitosan gel artificial muscle

NASA Astrophysics Data System (ADS)

Zhao, Gang; Yang, Junjie; Wang, Yujian; Zhao, Honghao; Fu, Yu; Zhang, Guangli; Yu, Shuqin; Wu, Yuda; Wei, Chengye; Liu, Xuxiong; Wang, Zhijie

2018-01-01

Bionic artificial muscle made from chitosan gel is an emerging type of the ionic electro active polymer with advantages of large deformation, low cost and environmental protection etc, which leads to a research focus and wide application in the fields of bionic engineering and intelligence material recently. In this paper, effects and improvement mechanisms of the direct casting and genipin cross-linking processes on response speed properties of the chitosan gel artificial muscle (CGAM) were mainly studied. Based on in-depth analysis of the CGAM response mechanism, a platform was built for testing the response performance of the CGAM, then its equivalent circuit and mathematical models were also established. Furthermore, control experiments were carried out to test and analyze several performances of the CGAM on response speed, electrical conductivity, mechanical properties and microstructure with different control variables. The experimental results illustrated that the CGAM assembled by direct casting enabled its electric actuating membrane and non-metallic electrode membrane tightly attached together with low contact resistance, which dramatically promoted the electrical conductivity of the CGAM resulting in nearly doubled response speed. Besides, different concentrations of genipin were adopted to cross-link the CGAM actuating membranes, and then it was found that the response speed of the uncross-linked CGAM was fast in the initial stage, but as time increased, it declined rapidly with poor steadiness. While there was no obvious decrease over time on the response speed of the CGAM cross-linked with low genipin concentration. Namely, its stability was getting better and better. In addition, the response speed of the CGAM cross-linked with low concentration of genipin was roughly the same as uncross-linked CGAM, which was quicker than that of high concentration. In this work, its internal mechanisms, feasible assembly technique and green modification method were provided to further explore the practical applications significantly.

Determinants of the reliability of ultrasound tomography sound speed estimates as a surrogate for volumetric breast density

PubMed Central

Khodr, Zeina G.; Sak, Mark A.; Pfeiffer, Ruth M.; Duric, Nebojsa; Littrup, Peter; Bey-Knight, Lisa; Ali, Haythem; Vallieres, Patricia; Sherman, Mark E.; Gierach, Gretchen L.

2015-01-01

Purpose: High breast density, as measured by mammography, is associated with increased breast cancer risk, but standard methods of assessment have limitations including 2D representation of breast tissue, distortion due to breast compression, and use of ionizing radiation. Ultrasound tomography (UST) is a novel imaging method that averts these limitations and uses sound speed measures rather than x-ray imaging to estimate breast density. The authors evaluated the reproducibility of measures of speed of sound and changes in this parameter using UST. Methods: One experienced and five newly trained raters measured sound speed in serial UST scans for 22 women (two scans per person) to assess inter-rater reliability. Intrarater reliability was assessed for four raters. A random effects model was used to calculate the percent variation in sound speed and change in sound speed attributable to subject, scan, rater, and repeat reads. The authors estimated the intraclass correlation coefficients (ICCs) for these measures based on data from the authors’ experienced rater. Results: Median (range) time between baseline and follow-up UST scans was five (1–13) months. Contributions of factors to sound speed variance were differences between subjects (86.0%), baseline versus follow-up scans (7.5%), inter-rater evaluations (1.1%), and intrarater reproducibility (∼0%). When evaluating change in sound speed between scans, 2.7% and ∼0% of variation were attributed to inter- and intrarater variation, respectively. For the experienced rater’s repeat reads, agreement for sound speed was excellent (ICC = 93.4%) and for change in sound speed substantial (ICC = 70.4%), indicating very good reproducibility of these measures. Conclusions: UST provided highly reproducible sound speed measurements, which reflect breast density, suggesting that UST has utility in sensitively assessing change in density. PMID:26429241

Determinants of the reliability of ultrasound tomography sound speed estimates as a surrogate for volumetric breast density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khodr, Zeina G.; Pfeiffer, Ruth M.; Gierach, Gretchen L., E-mail: GierachG@mail.nih.gov

Purpose: High breast density, as measured by mammography, is associated with increased breast cancer risk, but standard methods of assessment have limitations including 2D representation of breast tissue, distortion due to breast compression, and use of ionizing radiation. Ultrasound tomography (UST) is a novel imaging method that averts these limitations and uses sound speed measures rather than x-ray imaging to estimate breast density. The authors evaluated the reproducibility of measures of speed of sound and changes in this parameter using UST. Methods: One experienced and five newly trained raters measured sound speed in serial UST scans for 22 women (twomore » scans per person) to assess inter-rater reliability. Intrarater reliability was assessed for four raters. A random effects model was used to calculate the percent variation in sound speed and change in sound speed attributable to subject, scan, rater, and repeat reads. The authors estimated the intraclass correlation coefficients (ICCs) for these measures based on data from the authors’ experienced rater. Results: Median (range) time between baseline and follow-up UST scans was five (1–13) months. Contributions of factors to sound speed variance were differences between subjects (86.0%), baseline versus follow-up scans (7.5%), inter-rater evaluations (1.1%), and intrarater reproducibility (∼0%). When evaluating change in sound speed between scans, 2.7% and ∼0% of variation were attributed to inter- and intrarater variation, respectively. For the experienced rater’s repeat reads, agreement for sound speed was excellent (ICC = 93.4%) and for change in sound speed substantial (ICC = 70.4%), indicating very good reproducibility of these measures. Conclusions: UST provided highly reproducible sound speed measurements, which reflect breast density, suggesting that UST has utility in sensitively assessing change in density.« less

Proposed hardware architectures of particle filter for object tracking

NASA Astrophysics Data System (ADS)

Abd El-Halym, Howida A.; Mahmoud, Imbaby Ismail; Habib, SED

2012-12-01

In this article, efficient hardware architectures for particle filter (PF) are presented. We propose three different architectures for Sequential Importance Resampling Filter (SIRF) implementation. The first architecture is a two-step sequential PF machine, where particle sampling, weight, and output calculations are carried out in parallel during the first step followed by sequential resampling in the second step. For the weight computation step, a piecewise linear function is used instead of the classical exponential function. This decreases the complexity of the architecture without degrading the results. The second architecture speeds up the resampling step via a parallel, rather than a serial, architecture. This second architecture targets a balance between hardware resources and the speed of operation. The third architecture implements the SIRF as a distributed PF composed of several processing elements and central unit. All the proposed architectures are captured using VHDL synthesized using Xilinx environment, and verified using the ModelSim simulator. Synthesis results confirmed the resource reduction and speed up advantages of our architectures.

Seeing the forest for the trees: Networked workstations as a parallel processing computer

NASA Technical Reports Server (NTRS)

Breen, J. O.; Meleedy, D. M.

1992-01-01

Unlike traditional 'serial' processing computers in which one central processing unit performs one instruction at a time, parallel processing computers contain several processing units, thereby, performing several instructions at once. Many of today's fastest supercomputers achieve their speed by employing thousands of processing elements working in parallel. Few institutions can afford these state-of-the-art parallel processors, but many already have the makings of a modest parallel processing system. Workstations on existing high-speed networks can be harnessed as nodes in a parallel processing environment, bringing the benefits of parallel processing to many. While such a system can not rival the industry's latest machines, many common tasks can be accelerated greatly by spreading the processing burden and exploiting idle network resources. We study several aspects of this approach, from algorithms to select nodes to speed gains in specific tasks. With ever-increasing volumes of astronomical data, it becomes all the more necessary to utilize our computing resources fully.

Programmable logic controller performance enhancement by field programmable gate array based design.

PubMed

Patel, Dhruv; Bhatt, Jignesh; Trivedi, Sanjay

2015-01-01

PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement of performance and flexibility. Modelsim as simulation platform and VHDL used to translate, integrate and implement the logic circuit in FPGA. Xilinx's Spartan kit for implementation-testing and VB has been used for GUI development. Salient merits of the design include cost-effectiveness, miniaturization, user-friendliness, simplicity, along with lower power consumption, smaller scan time and higher speed. Various functionalities and applications like typical PLC and industrial alarm annunciator have been developed and successfully tested. Results of simulation, design and implementation have been reported. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Simulated parallel annealing within a neighborhood for optimization of biomechanical systems.

PubMed

Higginson, J S; Neptune, R R; Anderson, F C

2005-09-01

Optimization problems for biomechanical systems have become extremely complex. Simulated annealing (SA) algorithms have performed well in a variety of test problems and biomechanical applications; however, despite advances in computer speed, convergence to optimal solutions for systems of even moderate complexity has remained prohibitive. The objective of this study was to develop a portable parallel version of a SA algorithm for solving optimization problems in biomechanics. The algorithm for simulated parallel annealing within a neighborhood (SPAN) was designed to minimize interprocessor communication time and closely retain the heuristics of the serial SA algorithm. The computational speed of the SPAN algorithm scaled linearly with the number of processors on different computer platforms for a simple quadratic test problem and for a more complex forward dynamic simulation of human pedaling.

High Speed All-Optical Data Distribution Network

NASA Astrophysics Data System (ADS)

Braun, Steve; Hodara, Henri

2017-11-01

This article describes the performance and capabilities of an all-optical network featuring low latency, high speed file transfer between serially connected optical nodes. A basic component of the network is a network interface card (NIC) implemented through a unique planar lightwave circuit (PLC) that performs add/drop data and optical signal amplification. The network uses a linear bus topology with nodes in a "T" configuration, as described in the text. The signal is sent optically (hence, no latency) to all nodes via wavelength division multiplexing (WDM), with each node receiver tuned to wavelength of choice via an optical de-multiplexer. Each "T" node routes a portion of the signal to/from the bus through optical couplers, embedded in the network interface card (NIC), to each of the 1 through n computers.

Radiation-Tolerant Dual Data Bus

NASA Technical Reports Server (NTRS)

Kinstler, Gary A.

2007-01-01

An architecture, and a method of utilizing the architecture, have been proposed to enable error-free operation of a data bus that includes, and is connected to, commercial off-the-shelf (COTS) circuits and components that are inherently susceptible to singleevent upsets [SEUs (bit flips caused by impinging high-energy particles and photons)]. The architecture and method are applicable, more specifically, to data-bus circuitry based on the Institute for Electrical and Electronics Engineers (IEEE) 1394b standard for a high-speed serial bus.

Missile Manufacturing Technology Conference Held at Hilton Head Island, South Carolina on 22-26 September 1975. Panel Presentations. Test Equipment

DTIC Science & Technology

1975-01-01

in the computer in 16 bit parallel computer DIO transfers at the max- imum computer I/O speed. it then transmits this data in a bit- serial echo...maximum DIO rate under computer interrupt control. The LCI also provides station interrupt information for transfer to the computer under computer...been in daily operation since 1973. The SAM-D Missile system is currently in the Engineering De - velopment phase which precedes the Production and

Classification of Non-Time-Locked Rapid Serial Visual Presentation Events for Brain-Computer Interaction Using Deep Learning

DTIC Science & Technology

2014-07-08

internction ( BCI ) system allows h uman subjects to communicate with or control an extemal device with their brain signals [1], or to use those brain...signals to interact with computers, environments, or even other humans [2]. One application of BCI is to use brnin signals to distinguish target...images within a large collection of non-target images [2]. Such BCI -based systems can drastically increase the speed of target identification in

Stages of change concept of the transtheoretical model for healthy eating links health literacy and diabetes knowledge to glycemic control in people with type 2 diabetes.

PubMed

Tseng, Hsu-Min; Liao, Shu-Fen; Wen, Yu-Ping; Chuang, Yuh-Jue

2017-02-01

Health literacy has been recognized as a key construct associated with clinical outcomes; however, few studies have explored the mechanism underlying the association. The transtheoretical model (TTM) has long been considered a useful conceptualization in the process of intentional behavior change. Stages of change lies at the heart of the TTM as studies of change have found that people move through a series of stages when modifying behavior. This study focuses on the role of knowledge and stages of change (SOC) as serial mediators linking health literacy to glycemic control. In this cross-sectional survey, a total of 232 patients with type 2 diabetes participated in this study. Participants completed questionnaires for assessing health literacy, readiness to consume healthy foods, and a dietary knowledge test specific to diabetes. Low health literacy was significantly associated with worse glycemic control. Statistical evaluation supported the serial mediation model, in which knowledge and SOC formed a serial mediation chain that accounted for the indirect effect of health literacy on glycemic control. In other words, dietary knowledge significantly motivated participants to move into the later stages of behavior change, which in turn improved the outcome of glycemic control. The results indicate that the ordering of mediators in the pathway between health literacy and health outcome may be complex, help explain the conflicting results of the past, and form a basis for the development of interventions promoting self-management of diabetes through glycemic control. Copyright © 2016. Published by Elsevier Ltd.

Effect of type of cognitive task and walking speed on cognitive-motor interference during dual-task walking.

PubMed

Patel, P; Lamar, M; Bhatt, T

2014-02-28

We aimed to determine the effect of distinctly different cognitive tasks and walking speed on cognitive-motor interference of dual-task walking. Fifteen healthy adults performed four cognitive tasks: visuomotor reaction time (VMRT) task, word list generation (WLG) task, serial subtraction (SS) task, and the Stroop (STR) task while sitting and during walking at preferred-speed (dual-task normal walking) and slow-speed (dual-task slow-speed walking). Gait speed was recorded to determine effect on walking. Motor and cognitive costs were measured. Dual-task walking had a significant effect on motor and cognitive parameters. At preferred-speed, the motor cost was lowest for the VMRT task and highest for the STR task. In contrast, the cognitive cost was highest for the VMRT task and lowest for the STR task. Dual-task slow walking resulted in increased motor cost and decreased cognitive cost only for the STR task. Results show that the motor and cognitive cost of dual-task walking depends heavily on the type and perceived complexity of the cognitive task being performed. Cognitive cost for the STR task was low irrespective of walking speed, suggesting that at preferred-speed individuals prioritize complex cognitive tasks requiring higher attentional and processing resources over walking. While performing VMRT task, individuals preferred to prioritize more complex walking task over VMRT task resulting in lesser motor cost and increased cognitive cost for VMRT task. Furthermore, slow walking can assist in diverting greater attention towards complex cognitive tasks, improving its performance while walking. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Toward Identification of the Sexual Killer: A Comparison of Sexual Killers Engaging in Post-Mortem Sexual Interference and Non-Homicide Sexual Aggressors.

PubMed

Higgs, Tamsin; Carter, Adam J; Stefanska, Ewa B; Glorney, Emily

2017-08-01

Establishing a model of sexual assault reflecting psychosocial and behavioral characteristics of perpetrators of sexual killing and rape is necessary for development in risk assessment and intervention. Methodological variations in defining sexual killing have amalgamated serial and non-serial offenders and perpetrators with direct and indirect associations between killing and sexual arousal. This study defined sexual killing specifying that killing should be directly linked to sexual arousal, and sampled 48 sexual killers, operationalized to include only those engaging in post-mortem sexual interference, with one or two known female victims (non-serial), from prison service national (England and Wales) databases. These sexual killers were compared with 48 non-homicide, life or indeterminately sentenced sexual aggressors on psychological and crime scene characteristics. Contrary to previous research, fatal outcomes were associated with neither stranger victims nor weapon presence; sexual killing was characterized by severity of violence less so than non-fatal assault. Sexual killers more often reported problems with emotional loneliness, empathic concern, and sexual entitlement than the sexual aggressors. Theoretical and applied implications are discussed.

The Contribution of Short-Term Memory for Serial Order to Early Reading Acquisition: Evidence from a Longitudinal Study

ERIC Educational Resources Information Center

Perez, Trecy Martinez; Majerus, Steve; Poncelet, Martine

2012-01-01

Early reading acquisition skills have been linked to verbal short-term memory (STM) capacity. However, the nature of this relationship remains controversial because verbal STM, like reading acquisition, depends on the complexity of underlying phonological processing skills. This longitudinal study addressed the relation between STM and reading…

Length, Lexicality, and Articulatory Suppression in Immediate Recall: Evidence against the Articulatory Loop

ERIC Educational Resources Information Center

Romani, C.; McAlpine, S.; Olson, A.; Tsouknida, E.; Martin, R.

2005-01-01

Influential models of short-term memory have attributed the fact that short words are recalled better than longer words in serial recall (the length effect) to articulatory rehearsal. Crucial for this link is the finding that the length effect disappears under articulatory suppression. We show, instead, that, under suppression, the length effect…

Visual Search Deficits Are Independent of Magnocellular Deficits in Dyslexia

ERIC Educational Resources Information Center

Wright, Craig M.; Conlon, Elizabeth G.; Dyck, Murray

2012-01-01

The aim of this study was to investigate the theory that visual magnocellular deficits seen in groups with dyslexia are linked to reading via the mechanisms of visual attention. Visual attention was measured with a serial search task and magnocellular function with a coherent motion task. A large group of children with dyslexia (n = 70) had slower…

Revealing Word Order: Using Serial Position in Binomials to Predict Properties of the Speaker

ERIC Educational Resources Information Center

Iliev, Rumen; Smirnova, Anastasia

2016-01-01

Three studies test the link between word order in binomials and psychological and demographic characteristics of a speaker. While linguists have already suggested that psychological, cultural and societal factors are important in choosing word order in binomials, the vast majority of relevant research was focused on general factors and on broadly…

Maternal Mind-Mindedness and Children's School Readiness: A Longitudinal Study of Developmental Processes

ERIC Educational Resources Information Center

Bernier, Annie; McMahon, Catherine A.; Perrier, Rachel

2017-01-01

This study aimed to test a 5-wave sequential mediation model linking maternal mind-mindedness during infancy to children's school readiness in kindergarten through a serial mediation involving child language and effortful control in toddlerhood and the preschool years. Among a sample of 204 mother-child dyads, we assessed maternal mind-mindedness…

Photon Counting Using Edge-Detection Algorithm

NASA Technical Reports Server (NTRS)

Gin, Jonathan W.; Nguyen, Danh H.; Farr, William H.

2010-01-01

New applications such as high-datarate, photon-starved, free-space optical communications require photon counting at flux rates into gigaphoton-per-second regimes coupled with subnanosecond timing accuracy. Current single-photon detectors that are capable of handling such operating conditions are designed in an array format and produce output pulses that span multiple sample times. In order to discern one pulse from another and not to overcount the number of incoming photons, a detection algorithm must be applied to the sampled detector output pulses. As flux rates increase, the ability to implement such a detection algorithm becomes difficult within a digital processor that may reside within a field-programmable gate array (FPGA). Systems have been developed and implemented to both characterize gigahertz bandwidth single-photon detectors, as well as process photon count signals at rates into gigaphotons per second in order to implement communications links at SCPPM (serial concatenated pulse position modulation) encoded data rates exceeding 100 megabits per second with efficiencies greater than two bits per detected photon. A hardware edge-detection algorithm and corresponding signal combining and deserialization hardware were developed to meet these requirements at sample rates up to 10 GHz. The photon discriminator deserializer hardware board accepts four inputs, which allows for the ability to take inputs from a quadphoton counting detector, to support requirements for optical tracking with a reduced number of hardware components. The four inputs are hardware leading-edge detected independently. After leading-edge detection, the resultant samples are ORed together prior to deserialization. The deserialization is performed to reduce the rate at which data is passed to a digital signal processor, perhaps residing within an FPGA. The hardware implements four separate analog inputs that are connected through RF connectors. Each analog input is fed to a high-speed 1-bit comparator, which digitizes the input referenced to an adjustable threshold value. This results in four independent serial sample streams of binary 1s and 0s, which are ORed together at rates up to 10 GHz. This single serial stream is then deserialized by a factor of 16 to create 16 signal lines at a rate of 622.5 MHz or lower for input to a high-speed digital processor assembly. The new design and corresponding hardware can be employed with a quad-photon counting detector capable of handling photon rates on the order of multi-gigaphotons per second, whereas prior art was only capable of handling a single input at 1/4 the flux rate. Additionally, the hardware edge-detection algorithm has provided the ability to process 3-10 higher photon flux rates than previously possible by removing the limitation that photoncounting detector output pulses on multiple channels being ORed not overlap. Now, only the leading edges of the pulses are required to not overlap. This new photon counting digitizer hardware architecture supports a universal front end for an optical communications receiver operating at data rates from kilobits to over one gigabit per second to meet increased mission data volume requirements.

Virulence and pathogen multiplication: a serial passage experiment in the hypervirulent bacterial insect-pathogen Xenorhabdus nematophila.

PubMed

Chapuis, Élodie; Pagès, Sylvie; Emelianoff, Vanya; Givaudan, Alain; Ferdy, Jean-Baptiste

2011-01-31

The trade-off hypothesis proposes that the evolution of pathogens' virulence is shaped by a link between virulence and contagiousness. This link is often assumed to come from the fact that pathogens are contagious only if they can reach high parasitic load in the infected host. In this paper we present an experimental test of the hypothesis that selection on fast replication can affect virulence. In a serial passage experiment, we selected 80 lines of the bacterial insect-pathogen Xenorhabdus nematophila to multiply fast in an artificial culture medium. This selection resulted in shortened lag phase in our selected bacteria. We then injected these bacteria into insects and observed an increase in virulence. This could be taken as a sign that virulence in Xenorhabdus is linked to fast multiplication. But we found, among the selected lineages, either no link or a positive correlation between lag duration and virulence: the most virulent bacteria were the last to start multiplying. We then surveyed phenotypes that are under the control of the flhDC super regulon, which has been shown to be involved in Xenorhabdus virulence. We found that, in one treatment, the flhDC regulon has evolved rapidly, but that the changes we observed were not connected to virulence. All together, these results indicate that virulence is, in Xenorhabdus as in many other pathogens, a multifactorial trait. Being able to grow fast is one way to be virulent. But other ways exist which renders the evolution of virulence hard to predict.

A simulation-based study of HighSpeed TCP and its deployment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Souza, Evandro de

2003-05-01

The current congestion control mechanism used in TCP has difficulty reaching full utilization on high speed links, particularly on wide-area connections. For example, the packet drop rate needed to fill a Gigabit pipe using the present TCP protocol is below the currently achievable fiber optic error rates. HighSpeed TCP was recently proposed as a modification of TCP's congestion control mechanism to allow it to achieve reasonable performance in high speed wide-area links. In this research, simulation results showing the performance of HighSpeed TCP and the impact of its use on the present implementation of TCP are presented. Network conditions includingmore » different degrees of congestion, different levels of loss rate, different degrees of bursty traffic and two distinct router queue management policies were simulated. The performance and fairness of HighSpeed TCP were compared to the existing TCP and solutions for bulk-data transfer using parallel streams.« less

Reconfigurable signal processor designs for advanced digital array radar systems

NASA Astrophysics Data System (ADS)

Suarez, Hernan; Zhang, Yan (Rockee); Yu, Xining

2017-05-01

The new challenges originated from Digital Array Radar (DAR) demands a new generation of reconfigurable backend processor in the system. The new FPGA devices can support much higher speed, more bandwidth and processing capabilities for the need of digital Line Replaceable Unit (LRU). This study focuses on using the latest Altera and Xilinx devices in an adaptive beamforming processor. The field reprogrammable RF devices from Analog Devices are used as analog front end transceivers. Different from other existing Software-Defined Radio transceivers on the market, this processor is designed for distributed adaptive beamforming in a networked environment. The following aspects of the novel radar processor will be presented: (1) A new system-on-chip architecture based on Altera's devices and adaptive processing module, especially for the adaptive beamforming and pulse compression, will be introduced, (2) Successful implementation of generation 2 serial RapidIO data links on FPGA, which supports VITA-49 radio packet format for large distributed DAR processing. (3) Demonstration of the feasibility and capabilities of the processor in a Micro-TCA based, SRIO switching backplane to support multichannel beamforming in real-time. (4) Application of this processor in ongoing radar system development projects, including OU's dual-polarized digital array radar, the planned new cylindrical array radars, and future airborne radars.

Passive and electro-optic polymer photonics and InP electronics integration

NASA Astrophysics Data System (ADS)

Zhang, Z.; Katopodis, V.; Groumas, P.; Konczykowska, A.; Dupuy, J.-.; Beretta, A.; Dede, A.; Miller, E.; Choi, J. H.; Harati, P.; Jorge, F.; Nodjiadjim, V.; Dinu, R.; Cangini, G.; Vannucci, A.; Felipe, D.; Maese-Novo, A.; Keil, N.; Bach, H.-.; Schell, Martin; Avramopoulos, H.; Kouloumentas, Ch.

2015-05-01

Hybrid photonic integration allows individual components to be developed at their best-suited material platforms without sacrificing the overall performance. In the past few years a polymer-enabled hybrid integration platform has been established, comprising 1) EO polymers for constructing low-complexity and low-cost Mach-Zehnder modulators (MZMs) with extremely high modulation bandwidth; 2) InP components for light sources, detectors, and high-speed electronics including MUX drivers and DEMUX circuits; 3) Ceramic (AIN) RF board that links the electronic signals within the package. On this platform, advanced optoelectronic modules have been demonstrated, including serial 100 Gb/s [1] and 2x100 Gb/s [2] optical transmitters, but also 400 Gb/s optoelectronic interfaces for intra-data center networks [3]. To expand the device functionalities to an unprecedented level and at the same time improve the integration compatibility with diversified active / passive photonic components, we have added a passive polymer-based photonic board (polyboard) as the 4th material system. This passive polyboard allows for low-cost fabrication of single-mode waveguide networks, enables fast and convenient integration of various thin-film elements (TFEs) to control the light polarization, and provides efficient thermo-optic elements (TOEs) for wavelength tuning, light amplitude regulation and light-path switching.

On the Value of Estimating Human Arm Stiffness during Virtual Teleoperation with Robotic Manipulators

PubMed Central

Buzzi, Jacopo; Ferrigno, Giancarlo; Jansma, Joost M.; De Momi, Elena

2017-01-01

Teleoperated robotic systems are widely spreading in multiple different fields, from hazardous environments exploration to surgery. In teleoperation, users directly manipulate a master device to achieve task execution at the slave robot side; this interaction is fundamental to guarantee both system stability and task execution performance. In this work, we propose a non-disruptive method to study the arm endpoint stiffness. We evaluate how users exploit the kinetic redundancy of the arm to achieve stability and precision during the execution of different tasks with different master devices. Four users were asked to perform two planar trajectories following virtual tasks using both a serial and a parallel link master device. Users' arm kinematics and muscular activation were acquired and combined with a user-specific musculoskeletal model to estimate the joint stiffness. Using the arm kinematic Jacobian, the arm end-point stiffness was derived. The proposed non-disruptive method is capable of estimating the arm endpoint stiffness during the execution of virtual teleoperated tasks. The obtained results are in accordance with the existing literature in human motor control and show, throughout the tested trajectory, a modulation of the arm endpoint stiffness that is affected by task characteristics and hand speed and acceleration. PMID:29018319

Serial-order learning impairment and hypersensitivity-to-interference in dyscalculia.

PubMed

De Visscher, Alice; Szmalec, Arnaud; Van Der Linden, Lize; Noël, Marie-Pascale

2015-11-01

In the context of heterogeneity, the different profiles of dyscalculia are still hypothetical. This study aims to link features of mathematical difficulties to certain potential etiologies. First, we wanted to test the hypothesis of a serial-order learning deficit in adults with dyscalculia. For this purpose we used a Hebb repetition learning task. Second, we wanted to explore a recent hypothesis according to which hypersensitivity-to-interference hampers the storage of arithmetic facts and leads to a particular profile of dyscalculia. We therefore used interfering and non-interfering repeated sequences in the Hebb paradigm. A final test was used to assess the memory trace of the non-interfering sequence and the capacity to manipulate it. In line with our predictions, we observed that people with dyscalculia who show good conceptual knowledge in mathematics but impaired arithmetic fluency suffer from increased sensitivity-to-interference compared to controls. Secondly, people with dyscalculia who show a deficit in a global mathematical test suffer from a serial-order learning deficit characterized by a slow learning and a quick degradation of the memory trace of the repeated sequence. A serial-order learning impairment could be one of the explanations for a basic numerical deficit, since it is necessary for the number-word sequence acquisition. Among the different profiles of dyscalculia, this study provides new evidence and refinement for two particular profiles. Copyright © 2015 Elsevier B.V. All rights reserved.

Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

PubMed

Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

2017-06-22

This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

Psychophysics of reading. XVII. Low-vision performance with four types of electronically magnified text.

PubMed

Harland, S; Legge, G E; Luebker, A

1998-03-01

Most people with low vision need magnification to read. Page navigation is the process of moving a magnifier during reading. Modern electronic technology can provide many alternatives for navigating through text. This study compared reading speeds for four methods of displaying text. The four methods varied in their page-navigation demands. The closed-circuit television (CCTV) and MOUSE methods involved manual navigation. The DRIFT method (horizontally drifting text) involved no manual navigation, but did involve both smooth-pursuit and saccadic eye movements. The rapid serial visual presentation (RSVP) method involved no manual navigation, and relatively few eye movements. There were 7 normal subjects and 12 low-vision subjects (7 with central-field loss, CFL group, and 5 with central fields intact, CFI group). The subjects read 70-word passages at speeds that yielded good comprehension. Taking the CCTV reading speed as a benchmark, neither the normal nor low-vision subjects had significantly different speeds with the MOUSE method. As expected from the reduced navigational demands, normal subjects read faster with the DRIFT method (85% faster) and the RSVP method (169%). The CFI group read significantly faster with DRIFT (43%) and RSVP (38%). The CFL group showed no significant differences in reading speed for the four methods.

Cognitive processing speed is related to fall frequency in older adults with multiple sclerosis.

PubMed

Sosnoff, Jacob J; Balantrapu, Swathi; Pilutti, Lara A; Sandroff, Brian M; Morrison, Steven; Motl, Robert W

2013-08-01

To examine mobility, balance, fall risk, and cognition in older adults with multiple sclerosis (MS) as a function of fall frequency. Retrospective, cross-sectional design. University research laboratory. Community-dwelling persons with MS (N=27) aged between 50 and 75 years were divided into 2 groups-single-time (n=11) and recurrent (n=16; >2 falls/12 mo) fallers-on the basis of fall history. Not applicable. Mobility was assessed using a variety of measures including Multiple Sclerosis Walking Scale-12, walking speed (Timed 25-Foot Walk test), endurance (6-Minute Walk test), and functional mobility (Timed Up and Go test). Balance was assessed with the Berg Balance Scale, posturography, and self-reported balance confidence. Fall risk was assessed with the Physiological Profile Assessment. Cognitive processing speed was quantified with the Symbol Digit Modalities Test and the Paced Auditory Serial Addition Test. Recurrent fallers had slower cognitive processing speed than single-time fallers (P ≤.01). There was no difference in mobility, balance, or fall risk between recurrent and single-time fallers (P>.05). Results indicated that cognitive processing speed is associated with fall frequency and may have implications for fall prevention strategies targeting recurrent fallers with MS. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

X-15 ship #1 on lakebed

NASA Technical Reports Server (NTRS)

1960-01-01

The X-15 aircraft, ship #1 (56-6670), sits on the lakebed early in its illustrious career of high speed flight research. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation made three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

NASA Astrophysics Data System (ADS)

Tamborini, D.; Portaluppi, D.; Villa, F.; Tisa, S.; Tosi, A.

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs.

PubMed

Tamborini, D; Portaluppi, D; Villa, F; Tisa, S; Tosi, A

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

CAMAC throughput of a new RISC-based data acquisition computer at the DIII-D tokamak

NASA Astrophysics Data System (ADS)

Vanderlaan, J. F.; Cummings, J. W.

1993-10-01

The amount of experimental data acquired per plasma discharge at DIII-D has continued to grow. The largest shot size in May 1991 was 49 Mbyte; in May 1992, 66 Mbyte; and in April 1993, 80 Mbyte. The increasing load has prompted the installation of a new Motorola 88100-based MODCOMP computer to supplement the existing core of three older MODCOMP data acquisition CPU's. New Kinetic Systems CAMAC serial highway driver hardware runs on the 88100 VME bus. The new operating system is MODCOMP REAL/IX version of AT&T System V UNIX with real-time extensions and networking capabilities; future plans call for installation of additional computers of this type for tokamak and neutral beam control functions. Experiences with the CAMAC hardware and software will be chronicled, including observation of data throughput. The Enhanced Serial Highway crate controller is advertised as twice as fast as the previous crate controller, and computer I/O speeds are expected to also increase data rates.

Optimized static and video EEG rapid serial visual presentation (RSVP) paradigm based on motion surprise computation

NASA Astrophysics Data System (ADS)

Khosla, Deepak; Huber, David J.; Bhattacharyya, Rajan

2017-05-01

In this paper, we describe an algorithm and system for optimizing search and detection performance for "items of interest" (IOI) in large-sized images and videos that employ the Rapid Serial Visual Presentation (RSVP) based EEG paradigm and surprise algorithms that incorporate motion processing to determine whether static or video RSVP is used. The system works by first computing a motion surprise map on image sub-regions (chips) of incoming sensor video data and then uses those surprise maps to label the chips as either "static" or "moving". This information tells the system whether to use a static or video RSVP presentation and decoding algorithm in order to optimize EEG based detection of IOI in each chip. Using this method, we are able to demonstrate classification of a series of image regions from video with an azimuth value of 1, indicating perfect classification, over a range of display frequencies and video speeds.

Parallel Discrete Molecular Dynamics Simulation With Speculation and In-Order Commitment*†

PubMed Central

Khan, Md. Ashfaquzzaman; Herbordt, Martin C.

2011-01-01

Discrete molecular dynamics simulation (DMD) uses simplified and discretized models enabling simulations to advance by event rather than by timestep. DMD is an instance of discrete event simulation and so is difficult to scale: even in this multi-core era, all reported DMD codes are serial. In this paper we discuss the inherent difficulties of scaling DMD and present our method of parallelizing DMD through event-based decomposition. Our method is microarchitecture inspired: speculative processing of events exposes parallelism, while in-order commitment ensures correctness. We analyze the potential of this parallelization method for shared-memory multiprocessors. Achieving scalability required extensive experimentation with scheduling and synchronization methods to mitigate serialization. The speed-up achieved for a variety of system sizes and complexities is nearly 6× on an 8-core and over 9× on a 12-core processor. We present and verify analytical models that account for the achieved performance as a function of available concurrency and architectural limitations. PMID:21822327

Parallel Discrete Molecular Dynamics Simulation With Speculation and In-Order Commitment.

PubMed

Khan, Md Ashfaquzzaman; Herbordt, Martin C

2011-07-20

Discrete molecular dynamics simulation (DMD) uses simplified and discretized models enabling simulations to advance by event rather than by timestep. DMD is an instance of discrete event simulation and so is difficult to scale: even in this multi-core era, all reported DMD codes are serial. In this paper we discuss the inherent difficulties of scaling DMD and present our method of parallelizing DMD through event-based decomposition. Our method is microarchitecture inspired: speculative processing of events exposes parallelism, while in-order commitment ensures correctness. We analyze the potential of this parallelization method for shared-memory multiprocessors. Achieving scalability required extensive experimentation with scheduling and synchronization methods to mitigate serialization. The speed-up achieved for a variety of system sizes and complexities is nearly 6× on an 8-core and over 9× on a 12-core processor. We present and verify analytical models that account for the achieved performance as a function of available concurrency and architectural limitations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, T.; Smith, K.S.; Severino, F.

A critical capability of the new RHIC low level rf (LLRF) system is the ability to synchronize signals across multiple locations. The 'Update Link' provides this functionality. The 'Update Link' is a deterministic serial data link based on the Xilinx RocketIO protocol that is broadcast over fiber optic cable at 1 gigabit per second (Gbps). The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources. The new RHIC LLRF was designed to be a flexible, modular system. The system is constructed of numerous independent RF Controller chassis. To providemore » synchronization among all of these chassis, the Update Link system was designed. The Update Link system provides a low latency, deterministic data path to broadcast information to all receivers in the system. The Update Link system is based on a central hub, the Update Link Master (ULM), which generates the data stream that is distributed via fiber optic links. Downstream chassis have non-deterministic connections back to the ULM that allow any chassis to provide data that is broadcast globally.« less

Real-world hydrologic assessment of a fully-distributed hydrological model in a parallel computing environment

NASA Astrophysics Data System (ADS)

Vivoni, Enrique R.; Mascaro, Giuseppe; Mniszewski, Susan; Fasel, Patricia; Springer, Everett P.; Ivanov, Valeriy Y.; Bras, Rafael L.

2011-10-01

SummaryA major challenge in the use of fully-distributed hydrologic models has been the lack of computational capabilities for high-resolution, long-term simulations in large river basins. In this study, we present the parallel model implementation and real-world hydrologic assessment of the Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator (tRIBS). Our parallelization approach is based on the decomposition of a complex watershed using the channel network as a directed graph. The resulting sub-basin partitioning divides effort among processors and handles hydrologic exchanges across boundaries. Through numerical experiments in a set of nested basins, we quantify parallel performance relative to serial runs for a range of processors, simulation complexities and lengths, and sub-basin partitioning methods, while accounting for inter-run variability on a parallel computing system. In contrast to serial simulations, the parallel model speed-up depends on the variability of hydrologic processes. Load balancing significantly improves parallel speed-up with proportionally faster runs as simulation complexity (domain resolution and channel network extent) increases. The best strategy for large river basins is to combine a balanced partitioning with an extended channel network, with potential savings through a lower TIN resolution. Based on these advances, a wider range of applications for fully-distributed hydrologic models are now possible. This is illustrated through a set of ensemble forecasts that account for precipitation uncertainty derived from a statistical downscaling model.

Dopamine D1 and D3 Receptors Modulate Heroin-Induced Cognitive Impairment through Opponent Actions in Mice

PubMed Central

Zhu, Yongsheng; Wang, Yunpeng; Wei, Shuguang; Zhang, Hongbo; Yan, Peng; Li, Yunxiao; Qiao, Xiaomeng; Yin, Fangyuan

2017-01-01

Abstract Background: Chronic abuse of heroin leads to long-lasting and complicated cognitive impairment. Dopamine receptors are critically involved in the impulsive drug-driven behavior and the altered attention, processing speed, and mental flexibility that are associated with higher relapse rates. However, the effects of the different dopamine receptors and their possible involvement in heroin-induced cognitive impairment remain unclear. Methods: The 5-choice serial reaction time task was used to investigate the profiles of heroin-induced cognitive impairment in mice. The expression levels of dopamine D1- and D2-like receptors in the prefrontal cortex, nucleus accumbens, and caudate-putamen were determined. The effects of dopamine receptors on heroin-induced impulsivity in the 5-choice serial reaction time task were examined by agonist/antagonist treatment on D1 or D3 receptor mutant mice. Results: Systemic heroin administration influences several variables in the 5-choice serial reaction time task, most notably premature responses, a measure of motor impulsivity. These behavioral impairments are associated with increased D1 receptor and decreased D3 receptor mRNA and protein levels in 3 observed brain areas. The heroin-evoked increase in premature responses is mimicked by a D1 agonist and prevented by a D1 antagonist or genetic ablation of the D1 receptor gene. In contrast, a D3 agonist decreases both basal and heroin-evoked premature responses, while genetic ablation of the D3 receptor gene results in increased basal and heroin-evoked premature responses. Conclusions: Heroin-induced impulsive behavior in the 5-choice serial reaction time task is oppositely modulated by D1 and D3 receptor activation. The D1 receptors in the cortical-mesolimbic region play an indispensable role in modulating such behaviors. PMID:27815417

Use of CCSDS Packets Over SpaceWire to Control Hardware

NASA Technical Reports Server (NTRS)

Haddad, Omar; Blau, Michael; Haghani, Noosha; Yuknis, William; Albaijes, Dennis

2012-01-01

For the Lunar Reconnaissance Orbiter, the Command and Data Handling subsystem consisted of several electronic hardware assemblies that were connected with SpaceWire serial links. Electronic hardware would be commanded/controlled and telemetry data was obtained using the SpaceWire links. Prior art focused on parallel data buses and other types of serial buses, which were not compatible with the SpaceWire and the core flight executive (CFE) software bus. This innovation applies to anything that utilizes both SpaceWire networks and the CFE software. The CCSDS (Consultative Committee for Space Data Systems) packet contains predetermined values in its payload fields that electronic hardware attached at the terminus of the SpaceWire node would decode, interpret, and execute. The hardware s interpretation of the packet data would enable the hardware to change its state/configuration (command) or generate status (telemetry). The primary purpose is to provide an interface that is compatible with the hardware and the CFE software bus. By specifying the format of the CCSDS packet, it is possible to specify how the resulting hardware is to be built (in terms of digital logic) that results in a hardware design that can be controlled by the CFE software bus in the final application

High-Speed TCP Testing

NASA Technical Reports Server (NTRS)

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.

Two-Photon Imaging with Diffractive Optical Elements

PubMed Central

Watson, Brendon O.; Nikolenko, Volodymyr; Yuste, Rafael

2009-01-01

Two-photon imaging has become a useful tool for optical monitoring of neural circuits, but it requires high laser power and serial scanning of each pixel in a sample. This results in slow imaging rates, limiting the measurements of fast signals such as neuronal activity. To improve the speed and signal-to-noise ratio of two-photon imaging, we introduce a simple modification of a two-photon microscope, using a diffractive optical element (DOE) which splits the laser beam into several beamlets that can simultaneously scan the sample. We demonstrate the advantages of DOE scanning by enhancing the speed and sensitivity of two-photon calcium imaging of action potentials in neurons from neocortical brain slices. DOE scanning can easily improve the detection of time-varying signals in two-photon and other non-linear microscopic techniques. PMID:19636390

Genetic Parallel Programming: design and implementation.

PubMed

Cheang, Sin Man; Leung, Kwong Sak; Lee, Kin Hong

2006-01-01

This paper presents a novel Genetic Parallel Programming (GPP) paradigm for evolving parallel programs running on a Multi-Arithmetic-Logic-Unit (Multi-ALU) Processor (MAP). The MAP is a Multiple Instruction-streams, Multiple Data-streams (MIMD), general-purpose register machine that can be implemented on modern Very Large-Scale Integrated Circuits (VLSIs) in order to evaluate genetic programs at high speed. For human programmers, writing parallel programs is more difficult than writing sequential programs. However, experimental results show that GPP evolves parallel programs with less computational effort than that of their sequential counterparts. It creates a new approach to evolving a feasible problem solution in parallel program form and then serializes it into a sequential program if required. The effectiveness and efficiency of GPP are investigated using a suite of 14 well-studied benchmark problems. Experimental results show that GPP speeds up evolution substantially.

Visual search for features and conjunctions in development.

PubMed

Lobaugh, N J; Cole, S; Rovet, J F

1998-12-01

Visual search performance was examined in three groups of children 7 to 12 years of age and in young adults. Colour and orientation feature searches and a conjunction search were conducted. Reaction time (RT) showed expected improvements in processing speed with age. Comparisons of RT's on target-present and target-absent trials were consistent with parallel search on the two feature conditions and with serial search in the conjunction condition. The RT results indicated searches for feature and conjunctions were treated similarly for children and adults. However, the youngest children missed more targets at the largest array sizes, most strikingly in conjunction search. Based on an analysis of speed/accuracy trade-offs, we suggest that low target-distractor discriminability leads to an undersampling of array elements, and is responsible for the high number of misses in the youngest children.

Remote Transmission at High Speed

NASA Technical Reports Server (NTRS)

2003-01-01

Omni and NASA Test Operations at Stennis entered a Dual-Use Agreement to develop the FOTR-125, a 125 megabit-per-second fiber-optic transceiver that allows accurate digital recordings over a great distance. The transceiver s fiber-optic link can be as long as 25 kilometers. This makes it much longer than the standard coaxial link, which can be no longer than 50 meters.The FOTR-125 utilizes laser diode transmitter modules and integrated receivers for the optical interface. Two transmitters and two receivers are employed at each end of the link with automatic or manual switchover to maximize the reliability of the communications link. NASA uses the transceiver in Stennis High-Speed Data Acquisition System (HSDAS). The HSDAS consists of several identical systems installed on the Center s test stands to process all high-speed data related to its propulsion test programs. These transceivers allow the recorder and HSDAS controls to be located in the Test Control Center in a remote location while the digitizer is located on the test stand.

High-speed digital fiber optic links for satellite traffic

NASA Technical Reports Server (NTRS)

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

1989-01-01

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

FPGA-based GEM detector signal acquisition for SXR spectroscopy system

NASA Astrophysics Data System (ADS)

Wojenski, A.; Pozniak, K. T.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Zabolotny, W.; Chernyshova, M.; Czarski, T.; Malinowski, K.

2016-11-01

The presented work is related to the Gas Electron Multiplier (GEM) detector soft X-ray spectroscopy system for tokamak applications. The used GEM detector has one-dimensional, 128 channel readout structure. The channels are connected to the radiation-hard electronics with configurable analog stage and fast ADCs, supporting speeds of 125 MSPS for each channel. The digitalized data is sent directly to the FPGAs using fast serial links. The preprocessing algorithms are implemented in the FPGAs, with the data buffering made in the on-board 2Gb DDR3 memory chips. After the algorithmic stage, the data is sent to the Intel Xeon-based PC for further postprocessing using PCI-Express link Gen 2. For connection of multiple FPGAs, PCI-Express switch 8-to-1 was designed. The whole system can support up to 2048 analog channels. The scope of the work is an FPGA-based implementation of the recorder of the raw signal from GEM detector. Since the system will work in a very challenging environment (neutron radiation, intense electro-magnetic fields), the registered signals from the GEM detector can be corrupted. In the case of the very intense hot plasma radiation (e.g. laser generated plasma), the registered signals can overlap. Therefore, it is valuable to register the raw signals from the GEM detector with high number of events during soft X-ray radiation. The signal analysis will have the direct impact on the implementation of photon energy computation algorithms. As the result, the system will produce energy spectra and topological distribution of soft X-ray radiation. The advanced software was developed in order to perform complex system startup and monitoring of hardware units. Using the array of two one-dimensional GEM detectors it will be possible to perform tomographic reconstruction of plasma impurities radiation in the SXR region.

ICE-Based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

NASA Astrophysics Data System (ADS)

Bandura, K.; Cliche, J. F.; Dobbs, M. A.; Gilbert, A. J.; Ittah, D.; Mena Parra, J.; Smecher, G.

2016-03-01

New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2,048 digitizer inputs across 400MHz of bandwidth. Measured in N2× bandwidth, it is the largest radio correlator that is currently commissioning. Its digital back-end must exchange and reorganize the 6.6terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256 graphics processing unit (GPU) node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. ‘corner-turn’). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct, passive copper, full-mesh, high speed serial connections between sixteen circuit boards in a crate, to exchange data between crates, and to offload the data to a cluster of 256 GPU nodes using standard 10Gbit/s Ethernet links. The GPU nodes complete the corner-turn by combining data from all crates and then computing visibilities. Eye diagrams and frame error counters confirm error-free operation of the corner-turn network in both the currently operating CHIME Pathfinder telescope (a prototype for the full CHIME telescope) and a representative fraction of the full CHIME hardware providing an end-to-end system validation. An analysis of an equivalent corner-turn system built with Ethernet switches instead of custom passive data links is provided.

Early blindness alters the spatial organization of verbal working memory.

PubMed

Bottini, Roberto; Mattioni, Stefania; Collignon, Olivier

2016-10-01

Several studies suggest that serial order in working memory (WM) is grounded on space. For a list of ordered items held in WM, items at the beginning of the list are associated with the left side of space and items at the end of the list with the right side. This suggests that maintaining items in verbal WM is performed in strong analogy to writing these items down on a physical whiteboard for later consultation (The Mental Whiteboard Hypothesis). What drives this spatial mapping of ordered series in WM remains poorly understood. In the present study we tested whether visual experience is instrumental in establishing the link between serial order in WM and spatial processing. We tested early blind (EB), late blind (LB) and sighted individuals in an auditory WM task. Replicating previous studies, left-key responses were faster for early items in the list whereas later items facilitated right-key responses in the sighted group. The same effect was observed in LB individuals. In contrast, EB participants did not show any association between space and serial position in WM. These results suggest that early visual experience plays a critical role in linking ordered items in WM and spatial representations. The analogical spatial structure of WM may depend in part on the actual experience of using spatially organized devices (e.g., notes, whiteboards) to offload WM. These practices are largely precluded to EB individuals, who instead rely to mnemonic devices that are less spatially organized (e.g., recordings, vocal notes). The way we habitually organize information in the external world may bias the way we organize information in our WM. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selective reduction of afterload in right heart assist therapy: a mock loop study†.

PubMed

Hsu, Po-Lin; Hatam, Nima; Unterkofler, Jan; Goetzenich, Andreas; McIntyre, Madeleine; Wong, Kai Chun; Egger, Christina; Schmitz-Rode, Thomas; Autschbach, Rüdiger; Steinseifer, Ulrich

2014-07-01

The treatment of right ventricular failure is closely linked to effects on pulmonary vascular resistance and thus the right ventricular (RV) afterload. Medical therapy includes afterload-decreasing drugs such as nitric oxide and prostacycline. However, current devices for mechanical unloading of the right ventricle aim at a decrease in preload increasing the pulmonary volume loading. In our concept study, we tested a minimally invasive right ventricular assist device (MIRVAD) that specifically reduces the afterload. The MIRVAD is supposed to be a foldable device for temporary transvascular placement in the pulmonary artery. We incorporated a MIRVAD prototype into a mock circulatory loop that can reproduce haemodynamic interaction between the pump and the physiological system. Pulmonary hypertension (PH), right heart failure (RHF) and MIRVAD-assisted cases were simulated. The key haemodynamic parameters for RV unloading were recorded. Mock loop simulation attested to a sufficient right ventricular unloading by serial application of a miniaturized impeller pump in the pulmonary artery. The afterload, represented by the pulmonary arterial root pressure, was recovered to the healthy range (32.62-10.93 mmHg) for the simulated PH case. In the simulated RHF case, the impaired pulmonary perfusion increased from 43.4 to 88.8% of the healthy level and the total ventricular work reduced from 0.381 to 0.197 J at a pump speed of 3500 rpm. At pump speeds higher than 3500 rpm, the pulmonary valve remains constantly open and the right ventricular configuration changes into a simple perfused hollow body. The feasibility of RV unloading by a selective decrease in RV afterload was proved in principle. By alternation of the pump speed, gradual reloading in sense of a myocardial training may be achieved. The results will be validated by future animal trials where the relationship between the level of support and pulmonary vascular pressure can be investigated in vivo. Further device design concerning foldable impeller leaflets will be carried out. At a final stage, the crimped version is supposed to reach a size below 1 cm to facilitate minimally invasive insertion. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Massively Parallel Rogue Cell Detection using Serial Time-Encoded Amplified Microscopy of Inertially Ordered Cells in High Throughput Flow

DTIC Science & Technology

2013-06-01

couples  the  high-­‐speed  capability  of  the   STEAM  imager  and  differential  phase... air  bubbles  in  the  TPE  mix.  Moreover,  TPE  chips  were  also  successfully  sealed  to  other  substrates...dynamics,  and  microelectromechanical  systems  (MEMS)  via  laser-­‐scanning  surface   vibrometry ,  and   observation

Engineering model of the electric drives of separation device for simulation of automatic control systems of reactive power compensation by means of serially connected capacitors

NASA Astrophysics Data System (ADS)

Juromskiy, V. M.

2016-09-01

It is developed a mathematical model for an electric drive of high-speed separation device in terms of the modeling dynamic systems Simulink, MATLAB. The model is focused on the study of the automatic control systems of the power factor (Cosφ) of an actuator by compensating the reactive component of the total power by switching a capacitor bank in series with the actuator. The model is based on the methodology of the structural modeling of dynamic processes.

Development and Testing of a High-Speed Real-Time Kinematic Precise DGPS Positioning System Between Two Aircraft

DTIC Science & Technology

2006-09-01

work-horse for this thesis. He spent hours writing some of the more tedious code, and as much time helping me learn C++ and Linux . He was always there...compared with C++, and the need to use Linux as the operating system, the filter was coded using C++ and KDevelop [28] in SUSE LINUX Professional 9.2 [42...The driving factor for using Linux was the operating system’s ability to access the serial ports in a reliable fashion. Under the original MATLAB® and

Variable Delay Element For Jitter Control In High Speed Data Links

DOEpatents

Livolsi, Robert R.

2002-06-11

A circuit and method for decreasing the amount of jitter present at the receiver input of high speed data links which uses a driver circuit for input from a high speed data link which comprises a logic circuit having a first section (1) which provides data latches, a second section (2) which provides a circuit generates a pre-destorted output and for compensating for level dependent jitter having an OR function element and a NOR function element each of which is coupled to two inputs and to a variable delay element as an input which provides a bi-modal delay for pulse width pre-distortion, a third section (3) which provides a muxing circuit, and a forth section (4) for clock distribution in the driver circuit. A fifth section is used for logic testing the driver circuit.

It’s About Time -- Understanding China’s Strategic Patience

DTIC Science & Technology

2012-03-18

Einstein and Stephen 3 Hawking, made conceptualizing time easier to accept by linking time with space. Time and space are inherently linked together...same regardless of how you were moving - exactly as experiments and mathematics of the day showed them to be. In 1905, Albert Einstein published...speeds relative to each other. Einstein explained that when two objects are moving at independent constant speeds, emphasizing the relative motion

UDE-based control of variable-speed wind turbine systems

NASA Astrophysics Data System (ADS)

Ren, Beibei; Wang, Yeqin; Zhong, Qing-Chang

2017-01-01

In this paper, the control of a PMSG (permanent magnet synchronous generator)-based variable-speed wind turbine system with a back-to-back converter is considered. The uncertainty and disturbance estimator (UDE)-based control approach is applied to the regulation of the DC-link voltage and the control of the RSC (rotor-side converter) and the GSC (grid-side converter). For the rotor-side controller, the UDE-based vector control is developed for the RSC with PMSG control to facilitate the application of the MPPT (maximum power point tracking) algorithm for the maximum wind energy capture. For the grid-side controller, the UDE-based vector control is developed to control the GSC with the power reference generated by a UDE-based DC-link voltage controller. Compared with the conventional vector control, the UDE-based vector control can achieve reliable current decoupling control with fast response. Moreover, the UDE-based DC-link voltage regulation can achieve stable DC-link voltage under model uncertainties and external disturbances, e.g. wind speed variations. The effectiveness of the proposed UDE-based control approach is demonstrated through extensive simulation studies in the presence of coupled dynamics, model uncertainties and external disturbances under varying wind speeds. The UDE-based control is able to generate more energy, e.g. by 5% for the wind profile tested.

Two CMOS gate arrays for the EPACT experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winkert, G.

1992-08-01

Two semicustom CMOS digital gate arrays are described in this paper which have been developed for the Energetic Particles: Acceleration, Composition, and Transport (EPACT) experiment. The first device, the 'Event Counters: 16 by 24-bit' (EC1624), implements sixteen 24-bit ripple counters and has flexible counting and readout options. The second device, the 'Serial Transmitter/Receiver' (SXR), is a multi-personality chip that can be used at either end of a serial, synchronous communications data link. It can be configured as a master in a central control unit, or as one of many slaves within remote assemblies. Together a network of SXRs allows formore » commanding and verification of distributed control signals. Both gate arrays are radiation hardened and qualified for space flight use. The architecture of each chip is presented and the benefits to the experiment summarized.« less

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamborini, D., E-mail: davide.tamborini@polimi.it; Portaluppi, D.; Villa, F.

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically usefulmore » for time-correlated single-photon counting application) through an independent serial link.« less

Innovative on board payload optical architecture for high throughput satellites

NASA Astrophysics Data System (ADS)

Baudet, D.; Braux, B.; Prieur, O.; Hughes, R.; Wilkinson, M.; Latunde-Dada, K.; Jahns, J.; Lohmann, U.; Fey, D.; Karafolas, N.

2017-11-01

For the next generation of HighThroughPut (HTP) Telecommunications Satellites, space end users' needs will result in higher link speeds and an increase in the number of channels; up to 512 channels running at 10Gbits/s. By keeping electrical interconnections based on copper, the constraints in term of power dissipation, number of electrical wires and signal integrity will become too demanding. The replacement of the electrical links by optical links is the most adapted solution as it provides high speed links with low power consumption and no EMC/EMI. But replacing all electrical links by optical links of an On Board Payload (OBP) is challenging. It is not simply a matter of replacing electrical components with optical but rather the whole concept and architecture have to be rethought to achieve a high reliability and high performance optical solution. In this context, this paper will present the concept of an Innovative OBP Optical Architecture. The optical architecture was defined to meet the critical requirements of the application: signal speed, number of channels, space reliability, power dissipation, optical signals crossing and components availability. The resulting architecture is challenging and the need for new developments is highlighted. But this innovative optically interconnected architecture will substantially outperform standard electrical ones.

Grumman OV-1C in flight

NASA Technical Reports Server (NTRS)

1983-01-01

Grumman OV-1C in flight. This OV-1C Mohawk, serial #67-15932, was used in a joint NASA/US Army Aviation Engineering Flight Activity (USAAEFA) program to study a stall-speed warning system in the early 1980s. NASA designed and built an automated stall-speed warning system which presented both airspeed and stall speed to the pilot. Visual indication of impending stall would be displayed to the pilot as a cursor or pointer located on a conventional airspeed indicator. In addition, an aural warning at predetermined stall margins was presented to the pilot through a voice synthesizer. The Mohawk was developed by Grumman Aircraft as a photo observation and reconnaissance aircraft for the US Marines and the US Army. The OV-1 entered production in October 1959 and served the US Army in Europe, Korea, the Viet Nam War, Central and South America, Alaska, and during Desert Shield/Desert Storm in the Middle East. The Mohawk was retired from service in September 1996. 133 OV-1Cs were built, the 'C' designating the model which used an IR (infrared) imaging system to provide reconnaissance.

Single-mode temperature and polarisation-stable high-speed 850nm vertical cavity surface emitting lasers

NASA Astrophysics Data System (ADS)

Nazaruk, D. E.; Blokhin, S. A.; Maleev, N. A.; Bobrov, M. A.; Kuzmenkov, A. G.; Vasil'ev, A. P.; Gladyshev, A. G.; Pavlov, M. M.; Blokhin, A. A.; Kulagina, M. M.; Vashanova, K. A.; Zadiranov, Yu M.; Fefelov, A. G.; Ustinov, V. M.

2014-12-01

A new intracavity-contacted design to realize temperature and polarization-stable high-speed single-mode 850 nm vertical cavity surface emitting lasers (VCSELs) grown by molecular-beam epitaxy is proposed. Temperature dependences of static and dynamic characteristics of the 4.5 pm oxide aperture InGaAlAs VCSEL were investigated in detail. Due to optimal gain-cavity detuning and enhanced carrier localization in the active region the threshold current remains below 0.75 mA for the temperature range within 20-90°C, while the output power exceeds 1 mW up to 90°C. Single-mode operation with side-mode suppression ratio higher than 30 dB and orthogonal polarization suppression ratio more than 18 dB was obtained in the whole current and temperature operation range. Device demonstrates serial resistance less than 250 Ohm, which is rather low for any type of single-mode short- wavelength VCSELs. VCSEL demonstrates temperature robust high-speed operation with modulation bandwidth higher than 13 GHz in the entire temperature range of 20-90°C. Despite high resonance frequency the high-speed performance of developed VCSELs was limited by the cut-off frequency of the parasitic low pass filter created by device resistances and capacitances. The proposed design is promising for single-mode high-speed VCSEL applications in a wide spectral range.

Carotid flow pulsatility is higher in women with greater decrement in gait speed during multi-tasking.

PubMed

Gonzales, Joaquin U; James, C Roger; Yang, Hyung Suk; Jensen, Daniel; Atkins, Lee; Al-Khalil, Kareem; O'Boyle, Michael

2017-05-01

Central arterial hemodynamics is associated with cognitive impairment. Reductions in gait speed during walking while performing concurrent tasks known as dual-tasking (DT) or multi-tasking (MT) is thought to reflect the cognitive cost that exceeds neural capacity to share resources. We hypothesized that central vascular function would associate with decrements in gait speed during DT or MT. Gait speed was measured using a motion capture system in 56 women (30-80y) without mild-cognitive impairment. Dual-tasking was considered walking at a fast-pace while balancing a tray. Multi-tasking was the DT condition plus subtracting by serial 7's. Applanation tonometry was used for measurement of aortic stiffness and central pulse pressure. Doppler-ultrasound was used to measure blood flow velocity and β-stiffness index in the common carotid artery. The percent change in gait speed was larger for MT than DT (14.1±11.2 vs. 8.7±9.6%, p <0.01). Tertiles were formed based on the percent change in gait speed for each condition. No vascular parameters differed across tertiles for DT. In contrast, carotid flow pulsatility (1.85±0.43 vs. 1.47±0.42, p=0.02) and resistance (0.75±0.07 vs. 0.68±0.07, p=0.01) indices were higher in women with more decrement (third tertile) as compared to women with less decrement (first tertile) in gait speed during MT after adjusting for age, gait speed, and task error. Carotid pulse pressure and β-stiffness did not contribute to these tertile differences. Elevated carotid flow pulsatility and resistance are characteristics found in healthy women that show lower cognitive capacity to walk and perform multiple concurrent tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

Local intelligent electronic device (IED) rendering templates over limited bandwidth communication link to manage remote IED

DOEpatents

Bradetich, Ryan; Dearien, Jason A; Grussling, Barry Jakob; Remaley, Gavin

2013-11-05

The present disclosure provides systems and methods for remote device management. According to various embodiments, a local intelligent electronic device (IED) may be in communication with a remote IED via a limited bandwidth communication link, such as a serial link. The limited bandwidth communication link may not support traditional remote management interfaces. According to one embodiment, a local IED may present an operator with a management interface for a remote IED by rendering locally stored templates. The local IED may render the locally stored templates using sparse data obtained from the remote IED. According to various embodiments, the management interface may be a web client interface and/or an HTML interface. The bandwidth required to present a remote management interface may be significantly reduced by rendering locally stored templates rather than requesting an entire management interface from the remote IED. According to various embodiments, an IED may comprise an encryption transceiver.

X-15 launch from B-52 mothership

NASA Technical Reports Server (NTRS)

1959-01-01

This photo illustrates how the X-15 rocket-powered aircraft was taken aloft under the wing of a B-52. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. This was one of the early powered flights using a pair of XLR-11 engines (until the XLR-99 became available). The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of rated thrust (actual thrust reportedly climbed to 60,000 lb). North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used: a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years--June 1959 to Oct. 1968--and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft (over 67 mi) in a program to investigate all aspects of piloted hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

X-15A-2 with test pilot Pete Knight

NASA Technical Reports Server (NTRS)

1965-01-01

Air Force pilot William J. 'Pete' Knight is seen here in front of the X-15A-2 aircraft (56-6671). Pete Knight made 16 flights in the X-15, and set the world unofficial speed record for fixed wing aircraft, 4,520 mph (mach 6.7), in the X-15A-2. He also made one flight above 50 miles, qualifying him for astronaut wings. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of rated thrust (actual thrust reportedly climbed to 60,000 lb). North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used: a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years--June 1959 to Oct. 1968--and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft (over 67 mi) in a program to investigate all aspects of piloted hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

A digitalized silicon microgyroscope based on embedded FPGA.

PubMed

Xia, Dunzhu; Yu, Cheng; Wang, Yuliang

2012-09-27

This paper presents a novel digital miniaturization method for a prototype silicon micro-gyroscope (SMG) with the symmetrical and decoupled structure. The schematic blocks of the overall system consist of high precision analog front-end interface, high-speed 18-bit analog to digital convertor, a high-performance core Field Programmable Gate Array (FPGA) chip and other peripherals such as high-speed serial ports for transmitting data. In drive mode, the closed-loop drive circuit are implemented by automatic gain control (AGC) loop and software phase-locked loop (SPLL) based on the Coordinated Rotation Digital Computer (CORDIC) algorithm. Meanwhile, the sense demodulation module based on varying step least mean square demodulation (LMSD) are addressed in detail. All kinds of algorithms are simulated by Simulink and DSPbuilder tools, which is in good agreement with the theoretical design. The experimental results have fully demonstrated the stability and flexibility of the system.

A Digitalized Silicon Microgyroscope Based on Embedded FPGA

PubMed Central

Xia, Dunzhu; Yu, Cheng; Wang, Yuliang

2012-01-01

This paper presents a novel digital miniaturization method for a prototype silicon micro-gyroscope (SMG) with the symmetrical and decoupled structure. The schematic blocks of the overall system consist of high precision analog front-end interface, high-speed 18-bit analog to digital convertor, a high-performance core Field Programmable Gate Array (FPGA) chip and other peripherals such as high-speed serial ports for transmitting data. In drive mode, the closed-loop drive circuit are implemented by automatic gain control (AGC) loop and software phase-locked loop (SPLL) based on the Coordinated Rotation Digital Computer (CORDIC) algorithm. Meanwhile, the sense demodulation module based on varying step least mean square demodulation (LMSD) are addressed in detail. All kinds of algorithms are simulated by Simulink and DSPbuilder tools, which is in good agreement with the theoretical design. The experimental results have fully demonstrated the stability and flexibility of the system. PMID:23201990

4 Gbps Scalable Low-Voltage Signaling (SLVS) transceiver for pixel radiation detectors

NASA Astrophysics Data System (ADS)

Kadlubowski, Lukasz A.; Kmon, Piotr

2017-08-01

We report on the design of 4 Gbps Scalable Low-Voltage Signaling (SLVS) transceiver in 40nm CMOS technology for application-specific integrated circuits (ASICs) dedicated to pixel radiation detectors. Serial data are transmitted with +/-200mV differential swing around 200mV nominal common-mode level. The common-mode interference minimization is crucial in such a design, due to EMC requirements. For multi-gigabit-per-second speeds, the influence of power supply path becomes one of the most challenging design issues. Accurate modeling of supply pads at each step of the design is necessary. Our analysis shows that the utilization of multiple bond wires as well as separate power supply pads for bulk terminals connection of the transistors is essential to ensure proper operation of the transceiver. The design is a result of various trade-offs between speed, required operating conditions, common-mode interference as well as power and area consumption.

Experiences with ATM in a multivendor pilot system at Forschungszentrum Julich

NASA Astrophysics Data System (ADS)

Kleines, H.; Ziemons, K.; Zwoll, K.

1998-08-01

The ATM technology for high speed serial transmission provides a new quality of communication by introducing novel features in a LAN environment, especially support of real time communication, of both LAN and WAN communication and of multimedia streams. In order to evaluate ATM for future DAQ systems and remote control systems as well as for a high speed picture archiving and communications system for medical images, Forschungszentrum Julich has build up a pilot system for the evaluation of ATM and standard low cost multimedia systems. It is a heterogeneous multivendor system containing a variety of switches and desktop solutions, employing different protocol options of ATM. The tests conducted in the pilot system revealed major difficulties regarding stability, interoperability and performance. The paper presents motivations, layout and results of the pilot system. Discussion of results concentrates on performance issues relevant for realistic applications, e.g., connection to a RAID system via NFS over ATM.

[A modified speech enhancement algorithm for electronic cochlear implant and its digital signal processing realization].

PubMed

Wang, Yulin; Tian, Xuelong

2014-08-01

In order to improve the speech quality and auditory perceptiveness of electronic cochlear implant under strong noise background, a speech enhancement system used for electronic cochlear implant front-end was constructed. Taking digital signal processing (DSP) as the core, the system combines its multi-channel buffered serial port (McBSP) data transmission channel with extended audio interface chip TLV320AIC10, so speech signal acquisition and output with high speed are realized. Meanwhile, due to the traditional speech enhancement method which has the problems as bad adaptability, slow convergence speed and big steady-state error, versiera function and de-correlation principle were used to improve the existing adaptive filtering algorithm, which effectively enhanced the quality of voice communications. Test results verified the stability of the system and the de-noising performance of the algorithm, and it also proved that they could provide clearer speech signals for the deaf or tinnitus patients.

Gray matter volume covariance patterns associated with gait speed in older adults: a multi-cohort MRI study.

PubMed

Blumen, Helena M; Brown, Lucy L; Habeck, Christian; Allali, Gilles; Ayers, Emmeline; Beauchet, Olivier; Callisaya, Michele; Lipton, Richard B; Mathuranath, P S; Phan, Thanh G; Pradeep Kumar, V G; Srikanth, Velandai; Verghese, Joe

2018-04-09

Accelerated gait decline in aging is associated with many adverse outcomes, including an increased risk for falls, cognitive decline, and dementia. Yet, the brain structures associated with gait speed, and how they relate to specific cognitive domains, are not well-understood. We examined structural brain correlates of gait speed, and how they relate to processing speed, executive function, and episodic memory in three non-demented and community-dwelling older adult cohorts (Overall N = 352), using voxel-based morphometry and multivariate covariance-based statistics. In all three cohorts, we identified gray matter volume covariance patterns associated with gait speed that included brain stem, precuneus, fusiform, motor, supplementary motor, and prefrontal (particularly ventrolateral prefrontal) cortex regions. Greater expression of these gray matter volume covariance patterns linked to gait speed were associated with better processing speed in all three cohorts, and with better executive function in one cohort. These gray matter covariance patterns linked to gait speed were not associated with episodic memory in any of the cohorts. These findings suggest that gait speed, processing speed (and to some extent executive functions) rely on shared neural systems that are subject to age-related and dementia-related change. The implications of these findings are discussed within the context of the development of interventions to compensate for age-related gait and cognitive decline.

A Parallel Multiclassification Algorithm for Big Data Using an Extreme Learning Machine.

PubMed

Duan, Mingxing; Li, Kenli; Liao, Xiangke; Li, Keqin

2018-06-01

As data sets become larger and more complicated, an extreme learning machine (ELM) that runs in a traditional serial environment cannot realize its ability to be fast and effective. Although a parallel ELM (PELM) based on MapReduce to process large-scale data shows more efficient learning speed than identical ELM algorithms in a serial environment, some operations, such as intermediate results stored on disks and multiple copies for each task, are indispensable, and these operations create a large amount of extra overhead and degrade the learning speed and efficiency of the PELMs. In this paper, an efficient ELM based on the Spark framework (SELM), which includes three parallel subalgorithms, is proposed for big data classification. By partitioning the corresponding data sets reasonably, the hidden layer output matrix calculation algorithm, matrix decomposition algorithm, and matrix decomposition algorithm perform most of the computations locally. At the same time, they retain the intermediate results in distributed memory and cache the diagonal matrix as broadcast variables instead of several copies for each task to reduce a large amount of the costs, and these actions strengthen the learning ability of the SELM. Finally, we implement our SELM algorithm to classify large data sets. Extensive experiments have been conducted to validate the effectiveness of the proposed algorithms. As shown, our SELM achieves an speedup on a cluster with ten nodes, and reaches a speedup with 15 nodes, an speedup with 20 nodes, a speedup with 25 nodes, a speedup with 30 nodes, and a speedup with 35 nodes.

Study on general theory of kinematics and dynamics of wheeled mobile robots

NASA Astrophysics Data System (ADS)

Tsukishima, Takahiro; Sasaki, Ken; Takano, Masaharu; Inoue, Kenji

1992-03-01

This paper proposes a general theory of kinematics and dynamics of wheeled mobile robots (WMRs). Unlike robotic manipulators which are modeled as 3-dimensional serial link mechanism, WMRs will be modeled as planar linkage mechanism with multiple links branching out from the base and/or another link. Since this model resembles a tree with branches, it will be called 'tree-structured-link'. The end of each link corresponds to the wheel which is in contact with the floor. In dynamics of WMR, equation of motion of a WMR is derived from joint input torques incorporating wheel dynamics. The wheel dynamics determines forces and moments acting on wheels as a function of slip velocity. This slippage of wheels is essential in dynamics of WMR. It will also be shown that the dynamics of WMR reduces to kinematics when slippage of wheels is neglected. Furthermore, the equation of dynamics is rewritten in velocity input form, since most of industrial motors are velocity controlled.

Perceptual and Cognitive Factors Imposing “Speed Limits” on Reading Rate: A Study with the Rapid Serial Visual Presentation

PubMed Central

Spinelli, Donatella; Zoccolotti, Pierluigi; De Luca, Maria; Martelli, Marialuisa

2016-01-01

Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate. PMID:27088226

Data compression/error correction digital test system. Appendix 2: Theory of operation

NASA Technical Reports Server (NTRS)

1972-01-01

An overall block diagram of the DC/EC digital system test is shown. The system is divided into two major units: the transmitter and the receiver. In operation, the transmitter and receiver are connected only by a real or simulated transmission link. The system inputs consist of: (1) standard format TV video, (2) two channels of analog voice, and (3) one serial PCM bit stream.

Generic controller dedicated to telemetry-controlled microsystems.

PubMed

Sodagar, Amir M; Wise, Kensall D; Najafi, Khalil

2006-01-01

This paper introduces a generic controller designed for telemetry-controlled microsystems. This controller receives a data packet through a serial link carrying a command word and the associated data, and is capable of generating a variety of control/timing signals according to the definition of the received command. The flexible microprogrammed architecture of the controller allows for defining the commands functions in an on-chip mask-programmable read-only memory.

Development of a robotic patient positioning system with a wide beam-angle range for fixed-beam particle therapy

NASA Astrophysics Data System (ADS)

Choi, Hongseok; Park, Jong-Oh; Ko, Seong Young; Park, Sukho; Cho, Sungho; Jung, Won-Gyun; Park, Yong Kyun; Kang, Jung Suk

2016-10-01

This paper describes a robotic patient positioning system (PPS) for a fixed-beam heavy-ion therapy system. In order to extend the limited irradiation angle range of the fixed beam, we developed a 6-degree-of-freedom (6-DOF) serial-link robotic arm and used it as the robotic PPS for the fixed-beam heavy-ion therapy system. This research aims to develop a robotic PPS for use in the Korea Heavy Ion Medical Accelerator (KHIMA) system, which is under development at the Korea Institute of Radiological & Medical Sciences (KIRAMS). In particular, we select constraints and criteria that will be used for designing and evaluating the robotic PPS through full consultation with KIRAMS. In accordance with the constraints and criteria, we develop a 6-DOF serial-link robotic arm that consists of six revolute joints for the robotic PPS, where the robotic arm covers the upper body of a patient as a treatment area and achieves a 15 ° roll and pitch angle in the treatment area without any collision. Various preliminary experiments confirm that the robotic PPS can meet all criteria for extension of the limited irradiation angle range in the treatment area and has a positioning repeatability of 0.275 mm.

SpaceWire Driver Software for Special DSPs

NASA Technical Reports Server (NTRS)

Clark, Douglas; Lux, James; Nishimoto, Kouji; Lang, Minh

2003-01-01

A computer program provides a high-level C-language interface to electronics circuitry that controls a SpaceWire interface in a system based on a space qualified version of the ADSP-21020 digital signal processor (DSP). SpaceWire is a spacecraft-oriented standard for packet-switching data-communication networks that comprise nodes connected through bidirectional digital serial links that utilize low-voltage differential signaling (LVDS). The software is tailored to the SMCS-332 application-specific integrated circuit (ASIC) (also available as the TSS901E), which provides three highspeed (150 Mbps) serial point-to-point links compliant with the proposed Institute of Electrical and Electronics Engineers (IEEE) Standard 1355.2 and equivalent European Space Agency (ESA) Standard ECSS-E-50-12. In the specific application of this software, the SpaceWire ASIC was combined with the DSP processor, memory, and control logic in a Multi-Chip Module DSP (MCM-DSP). The software is a collection of low-level driver routines that provide a simple message-passing application programming interface (API) for software running on the DSP. Routines are provided for interrupt-driven access to the two styles of interface provided by the SMCS: (1) the "word at a time" conventional host interface (HOCI); and (2) a higher performance "dual port memory" style interface (COMI).

32 x 16 CMOS smart pixel array for optical interconnects

NASA Astrophysics Data System (ADS)

Kim, Jongwoo; Guilfoyle, Peter S.; Stone, Richard V.; Hessenbruch, John M.; Choquette, Kent D.; Kiamilev, Fouad E.

2000-05-01

Free space optical interconnects can increase throughput capacities and eliminate much of the energy consumption required for `all electronic' systems. High speed optical interconnects can be achieved by integrating optoelectronic devices with conventional electronics. Smart pixel arrays have been developed which use optical interconnects. An individual smart pixel cell is composed of a vertical cavity surface emitting laser (VCSEL), a photodetector, an optical receiver, a laser driver, and digital logic circuitry. Oxide-confined VCSELs are being developed to operate at 850 nm with a threshold current of approximately 1 mA. Multiple quantum well photodetectors are being fabricated from AlGaAs for use with the 850 nm VCSELs. The VCSELs and photodetectors are being integrated with complementary metal oxide semiconductor (CMOS) circuitry using flip-chip bonding. CMOS circuitry is being integrated with a 32 X 16 smart pixel array. The 512 smart pixels are serially linked. Thus, an entire data stream may be clocked through the chip and output electrically by the last pixel. Electrical testing is being performed on the CMOS smart pixel array. Using an on-chip pseudo random number generator, a digital data sequence was cycled through the chip verifying operation of the digital circuitry. Although, the prototype chip was fabricated in 1.2 micrometers technology, simulations have demonstrated that the array can operate at 1 Gb/s per pixel using 0.5 micrometers technology.

Common Readout Unit (CRU) - A new readout architecture for the ALICE experiment

NASA Astrophysics Data System (ADS)

Mitra, J.; Khan, S. A.; Mukherjee, S.; Paul, R.

2016-03-01

The ALICE experiment at the CERN Large Hadron Collider (LHC) is presently going for a major upgrade in order to fully exploit the scientific potential of the upcoming high luminosity run, scheduled to start in the year 2021. The high interaction rate and the large event size will result in an experimental data flow of about 1 TB/s from the detectors, which need to be processed before sending to the online computing system and data storage. This processing is done in a dedicated Common Readout Unit (CRU), proposed for data aggregation, trigger and timing distribution and control moderation. It act as common interface between sub-detector electronic systems, computing system and trigger processors. The interface links include GBT, TTC-PON and PCIe. GBT (Gigabit transceiver) is used for detector data payload transmission and fixed latency path for trigger distribution between CRU and detector readout electronics. TTC-PON (Timing, Trigger and Control via Passive Optical Network) is employed for time multiplex trigger distribution between CRU and Central Trigger Processor (CTP). PCIe (Peripheral Component Interconnect Express) is the high-speed serial computer expansion bus standard for bulk data transport between CRU boards and processors. In this article, we give an overview of CRU architecture in ALICE, discuss the different interfaces, along with the firmware design and implementation of CRU on the LHCb PCIe40 board.

A high-resolution optical imaging system for obtaining the serial transverse section images of biologic tissue

NASA Astrophysics Data System (ADS)

Wu, Li; Zhang, Bin; Wu, Ping; Liu, Qian; Gong, Hui

2007-05-01

A high-resolution optical imaging system was designed and developed to obtain the serial transverse section images of the biologic tissue, such as the mouse brain, in which new knife-edge imaging technology, high-speed and high-sensitive line-scan CCD and linear air bearing stages were adopted and incorporated with an OLYMPUS microscope. The section images on the tip of the knife-edge were synchronously captured by the reflection imaging in the microscope while cutting the biologic tissue. The biologic tissue can be sectioned at interval of 250 nm with the same resolution of the transverse section images obtained in x and y plane. And the cutting job can be automatically finished based on the control program wrote specially in advance, so we save the mass labor of the registration of the vast images data. In addition, by using this system a larger sample can be cut than conventional ultramicrotome so as to avoid the loss of the tissue structure information because of splitting the tissue sample to meet the size request of the ultramicrotome.

GPURFSCREEN: a GPU based virtual screening tool using random forest classifier.

PubMed

Jayaraj, P B; Ajay, Mathias K; Nufail, M; Gopakumar, G; Jaleel, U C A

2016-01-01

In-silico methods are an integral part of modern drug discovery paradigm. Virtual screening, an in-silico method, is used to refine data models and reduce the chemical space on which wet lab experiments need to be performed. Virtual screening of a ligand data model requires large scale computations, making it a highly time consuming task. This process can be speeded up by implementing parallelized algorithms on a Graphical Processing Unit (GPU). Random Forest is a robust classification algorithm that can be employed in the virtual screening. A ligand based virtual screening tool (GPURFSCREEN) that uses random forests on GPU systems has been proposed and evaluated in this paper. This tool produces optimized results at a lower execution time for large bioassay data sets. The quality of results produced by our tool on GPU is same as that on a regular serial environment. Considering the magnitude of data to be screened, the parallelized virtual screening has a significantly lower running time at high throughput. The proposed parallel tool outperforms its serial counterpart by successfully screening billions of molecules in training and prediction phases.

A model linking immediate serial recall, the Hebb repetition effect and the learning of phonological word forms

PubMed Central

Page, M. P. A.; Norris, D.

2009-01-01

We briefly review the considerable evidence for a common ordering mechanism underlying both immediate serial recall (ISR) tasks (e.g. digit span, non-word repetition) and the learning of phonological word forms. In addition, we discuss how recent work on the Hebb repetition effect is consistent with the idea that learning in this task is itself a laboratory analogue of the sequence-learning component of phonological word-form learning. In this light, we present a unifying modelling framework that seeks to account for ISR and Hebb repetition effects, while being extensible to word-form learning. Because word-form learning is performed in the service of later word recognition, our modelling framework also subsumes a mechanism for word recognition from continuous speech. Simulations of a computational implementation of the modelling framework are presented and are shown to be in accordance with data from the Hebb repetition paradigm. PMID:19933143

Flexible robot control: Modeling and experiments

NASA Technical Reports Server (NTRS)

Oppenheim, Irving J.; Shimoyama, Isao

1989-01-01

Described here is a model and its use in experimental studies of flexible manipulators. The analytical model uses the equivalent of Rayleigh's method to approximate the displaced shape of a flexible link as the static elastic displacement which would occur under end rotations as applied at the joints. The generalized coordinates are thereby expressly compatible with joint motions and rotations in serial link manipulators, because the amplitude variables are simply the end rotations between the flexible link and the chord connecting the end points. The equations for the system dynamics are quite simple and can readily be formulated for the multi-link, three-dimensional case. When the flexible links possess mass and (polar moment of) inertia which are small compared to the concentrated mass and inertia at the joints, the analytical model is exact and displays the additional advantage of reduction in system dimension for the governing equations. Four series of pilot tests have been completed. Studies on a planar single-link system were conducted at Carnegie-Mellon University, and tests conducted at Toshiba Corporation on a planar two-link system were then incorporated into the study. A single link system under three-dimensional motion, displaying biaxial flexure, was then tested at Carnegie-Mellon.

Advanced digital signal processing for short haul optical fiber transmission beyond 100G

NASA Astrophysics Data System (ADS)

Kikuchi, Nobuhiko

2017-01-01

Significant increase of intra and inter data center traffic has been expected by the rapid spread of various network applications like SNS, IoT, mobile and cloud computing, and the needs for ultra-high speed and cost-effective short- to medium-reach optical fiber links beyond 100-Gbit/s is becoming larger and larger. Such high-speed links typically use multilevel modulation to lower signaling speed, which in turn face serious challenges in limited loss budget and waveform distortion tolerance. One of the promising techniques to overcome them is the use of advanced digital signal processing (DSP) and we review various DSP applications for short-to-medium reach applications.

Reading speed benefits from increased vertical word spacing in normal peripheral vision.

PubMed

Chung, Susana T L

2004-07-01

Crowding, the adverse spatial interaction due to proximity of adjacent targets, has been suggested as an explanation for slow reading in peripheral vision. The purposes of this study were to (1) demonstrate that crowding exists at the word level and (2) examine whether or not reading speed in central and peripheral vision can be enhanced with increased vertical word spacing. Five normal observers read aloud sequences of six unrelated four-letter words presented on a computer monitor, one word at a time, using rapid serial visual presentation (RSVP). Reading speeds were calculated based on the RSVP exposure durations yielding 80% correct. Testing was conducted at the fovea and at 5 degrees and 10 degrees in the inferior visual field. Critical print size (CPS) for each observer and at each eccentricity was first determined by measuring reading speeds for four print sizes using unflanked words. We then presented words at 0.8x or 1.4x CPS, with each target word flanked by two other words, one above and one below the target word. Reading speeds were determined for vertical word spacings (baseline-to-baseline separation between two vertically separated words) ranging from 0.8x to 2x the standard single-spacing, as well as the unflanked condition. At the fovea, reading speed increased with vertical word spacing up to about 1.2x to 1.5x the standard spacing and remained constant and similar to the unflanked reading speed at larger vertical word spacings. In the periphery, reading speed also increased with vertical word spacing, but it remained below the unflanked reading speed for all spacings tested. At 2x the standard spacing, peripheral reading speed was still about 25% lower than the unflanked reading speed for both eccentricities and print sizes. Results from a control experiment showed that the greater reliance of peripheral reading speed on vertical word spacing was also found in the right visual field. Increased vertical word spacing, which presumably decreases the adverse effect of crowding between adjacent lines of text, benefits reading speed. This benefit is greater in peripheral than central vision.

Out of Africa: modern human origins special feature: explaining worldwide patterns of human genetic variation using a coalescent-based serial founder model of migration outward from Africa.

PubMed

DeGiorgio, Michael; Jakobsson, Mattias; Rosenberg, Noah A

2009-09-22

Studies of worldwide human variation have discovered three trends in summary statistics as a function of increasing geographic distance from East Africa: a decrease in heterozygosity, an increase in linkage disequilibrium (LD), and a decrease in the slope of the ancestral allele frequency spectrum. Forward simulations of unlinked loci have shown that the decline in heterozygosity can be described by a serial founder model, in which populations migrate outward from Africa through a process where each of a series of populations is formed from a subset of the previous population in the outward expansion. Here, we extend this approach by developing a retrospective coalescent-based serial founder model that incorporates linked loci. Our model both recovers the observed decline in heterozygosity with increasing distance from Africa and produces the patterns observed in LD and the ancestral allele frequency spectrum. Surprisingly, although migration between neighboring populations and limited admixture between modern and archaic humans can be accommodated in the model while continuing to explain the three trends, a competing model in which a wave of outward modern human migration expands into a series of preexisting archaic populations produces nearly opposite patterns to those observed in the data. We conclude by developing a simpler model to illustrate that the feature that permits the serial founder model but not the archaic persistence model to explain the three trends observed with increasing distance from Africa is its incorporation of a cumulative effect of genetic drift as humans colonized the world.

Relationship between slow visual processing and reading speed in people with macular degeneration

PubMed Central

Cheong, Allen MY; Legge, Gordon E; Lawrence, Mary G; Cheung, Sing-Hang; Ruff, Mary A

2007-01-01

Purpose People with macular degeneration (MD) often read slowly even with adequate magnification to compensate for acuity loss. Oculomotor deficits may affect reading in MD, but cannot fully explain the substantial reduction in reading speed. Central-field loss (CFL) is often a consequence of macular degeneration, necessitating the use of peripheral vision for reading. We hypothesized that slower temporal processing of visual patterns in peripheral vision is a factor contributing to slow reading performance in MD patients. Methods Fifteen subjects with MD, including 12 with CFL, and five age-matched control subjects were recruited. Maximum reading speed and critical print size were measured with RSVP (Rapid Serial Visual Presentation). Temporal processing speed was studied by measuring letter-recognition accuracy for strings of three randomly selected letters centered at fixation for a range of exposure times. Temporal threshold was defined as the exposure time yielding 80% recognition accuracy for the central letter. Results Temporal thresholds for the MD subjects ranged from 159 to 5881 ms, much longer than values for age-matched controls in central vision (13 ms, p<0.01). The mean temporal threshold for the 11 MD subjects who used eccentric fixation (1555.8 ± 1708.4 ms) was much longer than the mean temporal threshold (97.0 ms ± 34.2 ms, p<0.01) for the age-matched controls at 10° in the lower visual field. Individual temporal thresholds accounted for 30% of the variance in reading speed (p<0.05). Conclusion The significant association between increased temporal threshold for letter recognition and reduced reading speed is consistent with the hypothesis that slower visual processing of letter recognition is one of the factors limiting reading speed in MD subjects. PMID:17881032

COLAcode: COmoving Lagrangian Acceleration code

NASA Astrophysics Data System (ADS)

Tassev, Svetlin V.

2016-02-01

COLAcode is a serial particle mesh-based N-body code illustrating the COLA (COmoving Lagrangian Acceleration) method; it solves for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in Lagrangian Perturbation Theory (LPT). It differs from standard N-body code by trading accuracy at small-scales to gain computational speed without sacrificing accuracy at large scales. This is useful for generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing; such catalogs are needed to perform detailed error analysis for ongoing and future surveys of LSS.

A PDP-15 to industrial-14 interface at the Lewis Research Center's cyclotron

NASA Technical Reports Server (NTRS)

Kebberly, F. R.; Leonard, R. F.

1977-01-01

An interface (hardware and software) was built which permits the loading, monitoring, and control of a digital equipment industrial-14/30 programmable controller by a PDP-15 computer. The interface utilizes the serial mode for data transfer to and from the controller, so that the required hardware is essentially that of a teletype unit except for the speed of transmission. Software described here permits the user to load binary paper tape, read or load individual controller memory locations, and if desired turn controller outputs on and off directly from the computer.

Looking in the Eyes to Discriminate: Linking Infants' Habituation Speed to Looking Behaviour Using Faces

ERIC Educational Resources Information Center

Bolhuis, Jantina; Kolling, Thorsten; Knopf, Monika

2016-01-01

Studies showed that individual differences in encoding speed as well as looking behaviour during the encoding of facial stimuli can relate to differences in subsequent face discrimination. Nevertheless, a direct linkage between encoding speed and looking behaviour during the encoding of facial stimuli and the role of these encoding characteristics…

X-15 ship #3 on lakebed

NASA Technical Reports Server (NTRS)

1961-01-01

The X-15-3 (56-6672), seen here on the lakebed at Edwards Air Force Base, Edwards, California, was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1 serial number 56-6670, seen in this photo, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

Temporal precision and the capacity of auditory-verbal short-term memory.

PubMed

Gilbert, Rebecca A; Hitch, Graham J; Hartley, Tom

2017-12-01

The capacity of serially ordered auditory-verbal short-term memory (AVSTM) is sensitive to the timing of the material to be stored, and both temporal processing and AVSTM capacity are implicated in the development of language. We developed a novel "rehearsal-probe" task to investigate the relationship between temporal precision and the capacity to remember serial order. Participants listened to a sub-span sequence of spoken digits and silently rehearsed the items and their timing during an unfilled retention interval. After an unpredictable delay, a tone prompted report of the item being rehearsed at that moment. An initial experiment showed cyclic distributions of item responses over time, with peaks preserving serial order and broad, overlapping tails. The spread of the response distributions increased with additional memory load and correlated negatively with participants' auditory digit spans. A second study replicated the negative correlation and demonstrated its specificity to AVSTM by controlling for differences in visuo-spatial STM and nonverbal IQ. The results are consistent with the idea that a common resource underpins both the temporal precision and capacity of AVSTM. The rehearsal-probe task may provide a valuable tool for investigating links between temporal processing and AVSTM capacity in the context of speech and language abilities.

High-speed optical links for UAV applications

NASA Astrophysics Data System (ADS)

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

2017-02-01

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

Psychological effects of thought acceleration.

PubMed

Pronin, Emily; Jacobs, Elana; Wegner, Daniel M

2008-10-01

Six experiments found that manipulations that increase thought speed also yield positive affect. These experiments varied in both the methods used for accelerating thought (i.e., instructions to brainstorm freely, exposure to multiple ideas, encouragement to plagiarize others' ideas, performance of easy cognitive tasks, narration of a silent video in fast-forward, and experimentally controlled reading speed) and the contents of the thoughts that were induced (from thoughts about money-making schemes to thoughts of five-letter words). The results suggested that effects of thought speed on mood are partially rooted in the subjective experience of thought speed. The results also suggested that these effects can be attributed to the joy-enhancing effects of fast thinking (rather than only to the joy-killing effects of slow thinking). This work is inspired by observations of a link between "racing thoughts" and euphoria in cases of clinical mania, and potential implications of that observed link are discussed. (c) 2008 APA, all rights reserved

Stability Augmentation of Wind Farm using Variable Speed Permanent Magnet Synchronous Generator

NASA Astrophysics Data System (ADS)

Rosyadi, Marwan; Muyeen, S. M.; Takahashi, Rion; Tamura, Junji

This paper presents a new control strategy of variable speed permanent magnet wind generator for stability augmentation of wind farm including fixed speed wind turbine with Induction Generator (IG). A new control scheme is developed for two levels back-to-back converters of Permanent Magnet Synchronous Generator (PMSG), by which both active and reactive powers delivered to the grid can be controlled easily. To avoid the converter damage, the DC link protection controller is also proposed in order to protect the dc link circuit during fault condition. To evaluate the control capability of the proposed controllers, simulations are performed on two model systems composed of wind farms connected to an infinite bus. From transient and steady state analyses by using PSCAD/EMTDC, it is concluded that the proposed control scheme is very effective to improve the stability of wind farm for severe network disturbance and randomly fluctuating wind speed.

Reading Speed Does Not Benefit from Increased Line Spacing in AMD Patients

PubMed Central

CHUNG, SUSANA T. L.; JARVIS, SAMUEL H.; WOO, STANLEY Y.; HANSON, KARA; JOSE, RANDALL T.

2009-01-01

Purpose Crowding, the adverse spatial interaction due to the proximity of adjacent targets, has been suggested as an explanation for slow reading in peripheral vision. Previously, we showed that increased line spacing, which presumably reduces crowding between adjacent lines of text, improved reading speed in the normal periphery (Chung, Optom Vis Sci 2004;81:525–35). The purpose of this study was to examine whether or not individuals with age-related macular degeneration (AMD) would benefit from increased line spacing for reading. Methods Experiment 1: Eight subjects with AMD read aloud 100-word passages rendered at five line spacings: the standard single spacing, 1.5×, 2×, 3×, and 4× the standard spacing. Print sizes were 1× and 2× of the critical print size. Reading time and number of reading errors for each passage were measured to compute the reading speed. Experiment 2: Four subjects with AMD read aloud sequences of six 4-letter words, presented on a computer monitor using the rapid serial visual presentation (RSVP) paradigm. Target words were presented singly, or flanked above and below by two other words that changed in synchrony with the target word, at various vertical word separations. Print size was 2× the critical print size. Reading speed was calculated based on the RSVP exposure duration that yielded 80% of the words read correctly. Results Averaged across subjects, reading speeds for passages were virtually constant for the range of line spacings tested. For sequences of unrelated words, reading speeds were also virtually constant for the range of vertical word separations tested, except at the smallest (standard) separation at which reading speed was lower. Conclusions Contrary to the previous finding that reading speed improved in normal peripheral vision, increased line spacing in passages, or increased vertical separation between words in RSVP, did not lead to improved reading speed in people with AMD. PMID:18772718

The Effect of Letter-stroke Boldness on Reading Speed in Central and Peripheral Vision

PubMed Central

Bernard, Jean-Baptiste; Kumar, Girish; Junge, Jasmine; Chung, Susana T.L.

2013-01-01

People with central vision loss often prefer boldface print over normal print for reading. However, little is known about how reading speed is influenced by the letter-stroke boldness of font. In this study, we examined the reliance of reading speed on stroke boldness, and determined whether this reliance differs between the normal central and peripheral vision. Reading speed was measured using the rapid serial visual presentation paradigm, where observers with normal vision read aloud short single sentences presented on a computer monitor, one word at a time. Text was rendered in Courier at six levels of boldness, defined as the stroke-width normalized to that of the standard Courier font: 0.27, 0.72, 1, 1.48, 1.89 and 3.04× the standard. Testings were conducted at the fovea and 10° in the inferior visual field. Print sizes used were 0.8× and 1.4× the critical print size (smallest print size that can be read at the maximum reading speed). At the fovea, reading speed was invariant for the middle four levels of boldness, but dropped by 23.3% for the least and the most bold text. At 10° eccentricity, reading speed was virtually the same for all boldness <1, but showed a poorer tolerance to bolder text, dropping by 21.5% for 1.89x boldness and 51% for the most bold (3.04x) text. These results could not be accounted for by the changes in print size or the RMS contrast of text associated with changes in stroke boldness. Our results suggest that contrary to the popular belief, reading speed does not benefit from bold text in the normal fovea and periphery. Excessive increase in stroke boldness may even impair reading speed, especially in the periphery. PMID:23523572

The effect of letter-stroke boldness on reading speed in central and peripheral vision.

PubMed

Bernard, Jean-Baptiste; Kumar, Girish; Junge, Jasmine; Chung, Susana T L

2013-05-24

People with central vision loss often prefer boldface print over normal print for reading. However, little is known about how reading speed is influenced by the letter-stroke boldness of font. In this study, we examined the reliance of reading speed on stroke boldness, and determined whether this reliance differs between the normal central and peripheral vision. Reading speed was measured using the rapid serial visual presentation paradigm, where observers with normal vision read aloud short single sentences presented on a computer monitor, one word at a time. Text was rendered in Courier at six levels of boldness, defined as the stroke-width normalized to that of the standard Courier font: 0.27, 0.72, 1, 1.48, 1.89 and 3.04× the standard. Testings were conducted at the fovea and 10° in the inferior visual field. Print sizes used were 0.8× and 1.4× the critical print size (smallest print size that can be read at the maximum reading speed). At the fovea, reading speed was invariant for the middle four levels of boldness, but dropped by 23.3% for the least and the most bold text. At 10° eccentricity, reading speed was virtually the same for all boldness <1, but showed a poorer tolerance to bolder text, dropping by 21.5% for 1.89× boldness and 51% for the most bold (3.04×) text. These results could not be accounted for by the changes in print size or the RMS contrast of text associated with changes in stroke boldness. Our results suggest that contrary to the popular belief, reading speed does not benefit from bold text in the normal fovea and periphery. Excessive increase in stroke boldness may even impair reading speed, especially in the periphery. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dopamine D1 and D3 Receptors Modulate Heroin-Induced Cognitive Impairment through Opponent Actions in Mice.

PubMed

Zhu, Yongsheng; Wang, Yunpeng; Lai, Jianghua; Wei, Shuguang; Zhang, Hongbo; Yan, Peng; Li, Yunxiao; Qiao, Xiaomeng; Yin, Fangyuan

2017-03-01

Chronic abuse of heroin leads to long-lasting and complicated cognitive impairment. Dopamine receptors are critically involved in the impulsive drug-driven behavior and the altered attention, processing speed, and mental flexibility that are associated with higher relapse rates. However, the effects of the different dopamine receptors and their possible involvement in heroin-induced cognitive impairment remain unclear. The 5-choice serial reaction time task was used to investigate the profiles of heroin-induced cognitive impairment in mice. The expression levels of dopamine D1- and D2-like receptors in the prefrontal cortex, nucleus accumbens, and caudate-putamen were determined. The effects of dopamine receptors on heroin-induced impulsivity in the 5-choice serial reaction time task were examined by agonist/antagonist treatment on D1 or D3 receptor mutant mice. Systemic heroin administration influences several variables in the 5-choice serial reaction time task, most notably premature responses, a measure of motor impulsivity. These behavioral impairments are associated with increased D1 receptor and decreased D3 receptor mRNA and protein levels in 3 observed brain areas. The heroin-evoked increase in premature responses is mimicked by a D1 agonist and prevented by a D1 antagonist or genetic ablation of the D1 receptor gene. In contrast, a D3 agonist decreases both basal and heroin-evoked premature responses, while genetic ablation of the D3 receptor gene results in increased basal and heroin-evoked premature responses. Heroin-induced impulsive behavior in the 5-choice serial reaction time task is oppositely modulated by D1 and D3 receptor activation. The D1 receptors in the cortical-mesolimbic region play an indispensable role in modulating such behaviors. © The Author 2016. Published by Oxford University Press on behalf of CINP.

Statistical speed of quantum states: Generalized quantum Fisher information and Schatten speed

NASA Astrophysics Data System (ADS)

Gessner, Manuel; Smerzi, Augusto

2018-02-01

We analyze families of measures for the quantum statistical speed which include as special cases the quantum Fisher information, the trace speed, i.e., the quantum statistical speed obtained from the trace distance, and more general quantifiers obtained from the family of Schatten norms. These measures quantify the statistical speed under generic quantum evolutions and are obtained by maximizing classical measures over all possible quantum measurements. We discuss general properties, optimal measurements, and upper bounds on the speed of separable states. We further provide a physical interpretation for the trace speed by linking it to an analog of the quantum Cramér-Rao bound for median-unbiased quantum phase estimation.

Spread spectrum communication link using surface wave devices

NASA Technical Reports Server (NTRS)

Hunsinger, B. J.; Fugit, B. B.

1971-01-01

A fast lock-up, 8-MHz bandwidth 8,000 bit per second data rate spread spectrum communication link breadboard is described that is implemented using surface wave devices as the primary signal generators and signal processing elements. It uses surface wave tapped delay lines in the transmitter to generate the signals and in the receiver to detect them. The breadboard provides a measured processing gain for Gaussian noise of 31.5 dB which is within one dB of the theoretical optimum. This development demonstrates that spread spectrum receivers implemented with surface wave devices have sensitivities and complexities comparable to those of serial correlation receivers, but synchronization search times which are two to three orders of magnitude smaller.

Using Link Disconnection Entropy Disorder to Detect Fast Moving Nodes in MANETs.

PubMed

Alvarez, Carlos F; Palafox, Luis E; Aguilar, Leocundo; Sanchez, Mauricio A; Martinez, Luis G

2016-01-01

Mobile ad-hoc networks (MANETs) are dynamic by nature; this dynamism comes from node mobility, traffic congestion, and other transmission conditions. Metrics to evaluate the effects of those conditions shine a light on node's behavior in an ad-hoc network, helping to identify the node or nodes with better conditions of connection. In this paper, we propose a relative index to evaluate a single node reliability, based on the link disconnection entropy disorder using neighboring nodes as reference. Link disconnection entropy disorder is best used to identify fast moving nodes or nodes with unstable communications, this without the need of specialized sensors such as GPS. Several scenarios were studied to verify the index, measuring the effects of Speed and traffic density on the link disconnection entropy disorder. Packet delivery ratio is associated to the metric detecting a strong relationship, enabling the use of the link disconnection entropy disorder to evaluate the stability of a node to communicate with other nodes. To expand the utilization of the link entropy disorder, we identified nodes with higher speeds in network simulations just by using the link entropy disorder.

Effects of fourth-order dispersion in very high-speed optical time-division multiplexed transmission.

PubMed

Capmany, J; Pastor, D; Sales, S; Ortega, B

2002-06-01

We present a closed-form expression for computation of the output pulse's rms time width in an optical fiber link with up to fourth-order dispersion (FOD) by use of an optical source with arbitrary linewidth and chirp parameters. We then specialize the expression to analyze the effect of FOD on the transmission of very high-speed linear optical time-division multiplexing systems. By suitable source chirping, FOD can be compensated for to an upper link-length limit above which other techniques must be employed. Finally, a design formula to estimate the maximum attainable bit rate limited by FOD as a function of the link length is also presented.

Optimal link budget to maximize data receiving from remote sensing satellite at different ground stations

NASA Astrophysics Data System (ADS)

Godse, Vinay V.; Rukmini, B.

2016-10-01

Earth observation satellite plays a significant role for global situation awareness. The earth observation satellite uses imaging payloads in RF and IR bands, which carry huge amount of data, needs to be transferred during visibility of satellite over the ground station. Location of ground station plays a very important role in communication with LEO satellites, as orbital speed of LEO satellite is much higher than earth rotation speed. It will be accessible for particular equatorial ground station for a very short duration. In this paper we want to maximize data receiving by optimizing link budget and receiving data at higher elevation links. Data receiving at multiple ground stations is preferred to counter less pass duration due to higher elevation links. Our approach is to calculate link budget for remote sensing satellite with a fixed power input and varying different minimum elevation angles to obtain maximum data. The minimum pass duration should be above 3 minutes for effective communication. We are proposing to start process of command handling as soon as satellite is visible to particular ground station with low elevation angle up to 5 degree and start receiving data at higher elevation angles to receive data with higher speed. Cartosat-2B LEO earth observation satellite is taken for the case study. Cartosat-2B will complete around 14 passes over equator in a day, out of which only 4-5 passes will be useful for near equator ground stations. Our aim is to receive data at higher elevation angles at higher speed and increase amount of data download, criteria being minimum pass duration of 3 minutes, which has been set for selecting minimum elevation angle.

Grumman OV-1C in hangar

NASA Technical Reports Server (NTRS)

1983-01-01

Grumman OV-1C in the hangar used at the time by the Army at Edwards Air Force Base. This OV-1C Mohawk, serial #67-15932, was used in a joint NASA/US Army Aviation Engineering Flight Activity (USAAEFA) program to study a stall-speed warning system in the early 1980s. NASA designed and built an automated stall-speed warning system which presented both airspeed and stall speed to the pilot. Visual indication of impending stall would be displayed to the pilot as a cursor or pointer located on a conventional airspeed indicator. In addition, an aural warning at predetermined stall margins was presented to the pilot through a voice synthesizer. The Mohawk was developed by Grumman Aircraft as a photo observation and electronic reconnaissance aircraft for the US Marines and the US Army. The OV-1 entered production in October 1959 and served the US Army in Europe, Korea, the Viet Nam War, Central and South America, Alaska, and during Desert Shield/Desert Storm in the Middle East. The Mohawk was retired from service in September 1996. 133 OV-1Cs were built, the 'C' designating the model which used an IR (infrared) imaging system to provide reconnaissance.

Tailoring in risk communication by linking risk profiles and communication preferences: The case of speeding of young car drivers.

PubMed

Geber, Sarah; Baumann, Eva; Klimmt, Christoph

2016-12-01

Speeding is one of the most relevant risk behaviors for serious and fatal accidents, particularly among young drivers. This study presents a tailoring strategy for anti-speeding communication. By referring to their motivational dispositions toward speeding derived from motivational models of health behavior, young car drivers were segmented into different risk groups. In order to ensure that risk communication efforts would actually be capable to target these groups, the linkage between the risk profiles and communication preferences were explored. The study was conducted on the basis of survey data of 1168 German car drivers aged between 17 and 24 years. The data reveal four types of risk drivers significantly differing in their motivational profiles. Moreover, the findings show significant differences in communication habits and media use between these risk groups. By linking the risk profiles and communication preferences, implications for tailoring strategies of road safety communication campaigns are derived. Promising segmentation and targeting strategies are discussed also beyond the current case of anti-speeding campaigns. Copyright © 2015 Elsevier Ltd. All rights reserved.

A female advantage in the serial production of non-representational learned gestures.

PubMed

Chipman, Karen; Hampson, Elizabeth

2006-01-01

Clinical research has demonstrated a sex difference in the neuroanatomical organization of the limb praxis system. To test for a corresponding sex difference in the functioning of this system, we compared healthy men and women on a gesture production task modeled after those used in apraxia research. In two separate studies, participants were taught to perform nine non-representational gestures in response to computer-generated color cues. After extensive practice with the gestures, the color cues were placed on a timer and presented in randomized sequences at progressively faster speeds. A detailed videotape analysis revealed that women in both studies committed significantly fewer 'praxic' errors than men (i.e., errors that resembled those seen in limb apraxia). This was true during both the untimed practice trials and the speeded trials of the task, despite equivalent numbers of errors between the sexes in the 'non-praxic' (i.e., executory) error categories. Women in both studies also performed the task at significantly faster speeds than men. This finding was not accounted for by a female advantage in extraneous elements of the task, i.e., speed of color processing, associative retrieval, or motor execution. Together, the two studies provide convergent support for a female advantage in the efficiency of forelimb gesture production. They are consistent with emerging evidence of a sex difference in the anatomical organization of the praxis system.

Time lens assisted photonic sampling extraction

NASA Astrophysics Data System (ADS)

Petrillo, Keith Gordon

Telecommunication bandwidth demands have dramatically increased in recent years due to Internet based services like cloud computing and storage, large file sharing, and video streaming. Additionally, sensing systems such as wideband radar, magnetic imaging resonance systems, and complex modulation formats to handle large data transfer in telecommunications require high speed, high resolution analog-to-digital converters (ADCs) to interpret the data. Accurately processing and acquiring the information at next generation data rates from these systems has become challenging for electronic systems. The largest contributors to the electronic bottleneck are bandwidth and timing jitter which limit speed and reduce accuracy. Optical systems have shown to have at least three orders of magnitude increase in bandwidth capabilities and state of the art mode locked lasers have reduced timing jitters into thousands of attoseconds. Such features have encouraged processing signals without the use of electronics or using photonics to assist electronics. All optical signal processing has allowed the processing of telecommunication line rates up to 1.28 Tb/s and high resolution analog-to-digital converters in the 10s of gigahertz. The major drawback to these optical systems is the high cost of the components. The application of all optical processing techniques such as a time lens and chirped processing can greatly reduce bandwidth and cost requirements of optical serial to parallel converters and push photonically assisted ADCs into the 100s of gigahertz. In this dissertation, the building blocks to a high speed photonically assisted ADC are demonstrated, each providing benefits to its own respective application. A serial to parallel converter using a continuously operating time lens as an optical Fourier processor is demonstrated to fully convert a 160-Gb/s optical time division multiplexed signal to 16 10-Gb/s channels with error free operation. Using chirped processing, an optical sample and hold concept is demonstrated and analyzed as a resolution improvement to existing photonically assisted ADCs. Simulations indicate that the application of a continuously operating time lens to a photonically assisted sampling system can increase photonically sampled systems by an order of magnitude while acquiring properties similar to an optical sample and hold system.

SR-71 - Taxi on Ramp with Engines

NASA Technical Reports Server (NTRS)

1995-01-01

This photo shows a head-on shot of NASA's SR-71A aircraft taxiing on the ramp at NASA's Dryden Flight Research Center, Edwards, California, heat waves from its engines blurring the hangars in the background. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71B - Mach 3 Trainer in Flight at Sunset

NASA Technical Reports Server (NTRS)

1995-01-01

An SR-71B Blackbird aircraft, based at NASA's Dryden Flight Research Center, Edwards, California, is seen here silhouetted against the golden colors of a sunset sky on a 1995 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 in Flight over Rogers Dry Lakebed

NASA Technical Reports Server (NTRS)

1995-01-01

This photo shows NASA Dryden Flight Research Center's SR-71B, tail number 831, over Rogers Dry Lakebed during a July 1995 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71B - Mach 3 Trainer in Flight at Sunset

NASA Technical Reports Server (NTRS)

1995-01-01

The setting sun peeks beneath a SR-71B Blackbird, silhouetted against the orange hues of the western sky on a 1995 flight from at NASA's Dryden Flight Research Center, Edwards, California. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Tail #844 Landing at Edwards Air Force Base

NASA Technical Reports Server (NTRS)

1996-01-01

With distinctive heat waves trailing behind its engines, NASA Dryden Flight Research Center's SR-71A, tail number 844, lands at the Edwards AFB runway after a 1996 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71A on Ramp with Dual Max Afterburner Engines Firing

NASA Technical Reports Server (NTRS)

1998-01-01

This night shot shows one of NASA's SR-71 Blackbird research aircraft on the ramp at the Dryden Flight Research Center, Edwards, California, with both engines running in max afterburner. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71A - in Flight View from Tanker during an Airborne Refueling

NASA Technical Reports Server (NTRS)

1997-01-01

This photo shows a USAF tanker aircraft Boom Operator's or 'Boomer's' view of NASA Dryden Flight Research Center's SR-71A, tail number 844, following air refueling during a 1997 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71A - in Flight over Southern Sierra Nevada Mountains

NASA Technical Reports Server (NTRS)

1997-01-01

NASA Dryden Flight Research Center's SR-71A, tail number 844, banks away over the Sierra Nevada mountains after air refueling from a USAF tanker during a 1997 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71A in Flight with Test Fixture Mounted Atop the Aft Section of the Aircraft

NASA Technical Reports Server (NTRS)

1999-01-01

This close-up, head-on view of NASA's SR-71A Blackbird in flight shows the aircraft with an experimental test fixture mounted on the back of the airplane. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71B - in Flight - View from Air Force Tanker

NASA Technical Reports Server (NTRS)

1997-01-01

This look-down view shows NASA 831, an SR-71B flown by Dryden Flight Research Center, Edwards, California, as it cruises over the Mojave Desert. The photo was from an Air Force refueling tanker taken on a 1997 mission. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Mid-air Refueling with KC-135 Tanker

NASA Technical Reports Server (NTRS)

1995-01-01

NASA Dryden Flight Research Center's SR-71B, tail number 831, is seen here receiving air refueling from a USAF tanker during a July, 1995 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Ship #1 on Ramp

NASA Technical Reports Server (NTRS)

1994-01-01

This look-down, front view of NASA's SR-71A aircraft shows the Blackbird on the ramp at the Dryden Flight Research Center, Edwards, California. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 - In-flight from Tanker

NASA Technical Reports Server (NTRS)

1994-01-01

Dryden's SR-71B, NASA 831, slices across the snow-covered southern Sierra Nevada Mountains of California after being refueled by an Air Force tanker during a 1994 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

Fabrication and Testing of High-Speed-Single-Rotor and Compound-Rotor Systems

DTIC Science & Technology

2016-05-04

pitch link loads, hub loads, rotor wakes and performance of high -speed single-rotor and compound-rotor systems to support 1. REPORT DATE (DD-MM-YYYY) 4...Public Release; Distribution Unlimited UU UU UU UU 05-04-2016 14-Jul-2014 13-Jan-2016 Final Report: Fabrication and Testing of High -Speed Single- Rotor and...Final Report: Fabrication and Testing of High -Speed Single-Rotor and Compound-Rotor Systems Report Title The Alfred Gessow Rotorcraft Center has

Fabrication and Testing of High-Speed Single-Rotor and Compound-Rotor Systems

DTIC Science & Technology

2016-04-05

pitch link loads, hub loads, rotor wakes and performance of high -speed single-rotor and compound-rotor systems to support 1. REPORT DATE (DD-MM-YYYY) 4...Public Release; Distribution Unlimited UU UU UU UU 05-04-2016 14-Jul-2014 13-Jan-2016 Final Report: Fabrication and Testing of High -Speed Single- Rotor and...Final Report: Fabrication and Testing of High -Speed Single-Rotor and Compound-Rotor Systems Report Title The Alfred Gessow Rotorcraft Center has

Chemistry/Hematology Reporting Via the File Manager

PubMed Central

Tatarczuk, J. R.; Ginsburg, R. E.; Wu, A.; Schauble, M.

1981-01-01

A computerized reporting system was implemented to replace a simple manual cumulative laboratory chemistry report. Modification and expansion of the system was carried out with user participation, and the system now forms the nucleus for a complete automated laboratory system. It is linked to a master patient file which when fully developed will provide a suitable basis for a complete patient clinical information system. ANSI standard MUMPS was utilized and modules were developed and implemented in a serial fashion.

Examining the Links between Challenging Behaviors in Youth with ASD and Parental Stress, Mental Health, and Involvement: Applying an Adaptation of the Family Stress Model to Families of Youth with ASD

ERIC Educational Resources Information Center

Schiltz, Hillary K.; McVey, Alana J.; Magnus, Brooke; Dolan, Bridget K.; Willar, Kirsten S.; Pleiss, Sheryl; Karst, Jeffrey; Carson, Audrey M.; Caiozzo, Christina; Vogt, Elisabeth; Van Hecke, Amy Vaughan

2018-01-01

Raising a child with autism spectrum disorder (ASD) poses unique challenges that may impact parents' mental health and parenting experiences. The current study analyzed self-report data from 77 parents of youth with ASD. A serial multiple mediation model revealed that parenting stress (SIPA) and parental mental health (BAI and BDI-II) appears to…

Data Mining of Extremely Large Ad-Hoc Data Sets to Produce Reverse Web-Link Graphs

DTIC Science & Technology

2017-03-01

in most of the MR cases. From these studies , we also learned that computing -optimized instances should be chosen for serialized/compressed input data...maximum 200 words) Data mining can be a valuable tool, particularly in the acquisition of military intelligence. As the second study within a larger Naval...open web crawler data set Common Crawl. Similar to previous studies , this research employs MapReduce (MR) for sorting and categorizing output value

Gated high speed optical detector

NASA Technical Reports Server (NTRS)

Green, S. I.; Carson, L. M.; Neal, G. W.

1973-01-01

The design, fabrication, and test of two gated, high speed optical detectors for use in high speed digital laser communication links are discussed. The optical detectors used a dynamic crossed field photomultiplier and electronics including dc bias and RF drive circuits, automatic remote synchronization circuits, automatic gain control circuits, and threshold detection circuits. The equipment is used to detect binary encoded signals from a mode locked neodynium laser.

Detection of Peptide-based nanoparticles in blood plasma by ELISA.

PubMed

Bode, Gerard H; Pickl, Karin E; Sanchez-Purrà, Maria; Albaiges, Berta; Borrós, Salvador; Pötgens, Andy J G; Schmitz, Christoph; Sinner, Frank M; Losen, Mario; Steinbusch, Harry W M; Frank, Hans-Georg; Martinez-Martinez, Pilar

2015-01-01

The aim of the current study was to develop a method to detect peptide-linked nanoparticles in blood plasma. A convenient enzyme linked immunosorbent assay (ELISA) was developed for the detection of peptides functionalized with biotin and fluorescein groups. As a proof of principle, polymerized pentafluorophenyl methacrylate nanoparticles linked to biotin-carboxyfluorescein labeled peptides were intravenously injected in Wistar rats. Serial blood plasma samples were analyzed by ELISA and by liquid chromatography mass spectrometry (LC/MS) technology. The ELISA based method for the detection of FITC labeled peptides had a detection limit of 1 ng/mL. We were able to accurately measure peptides bound to pentafluorophenyl methacrylate nanoparticles in blood plasma of rats, and similar results were obtained by LC/MS. We detected FITC-labeled peptides on pentafluorophenyl methacrylate nanoparticles after injection in vivo. This method can be extended to detect nanoparticles with different chemical compositions.

Detection of Peptide-Based Nanoparticles in Blood Plasma by ELISA

PubMed Central

Bode, Gerard H.; Pickl, Karin E.; Sanchez-Purrà, Maria; Albaiges, Berta; Borrós, Salvador; Pötgens, Andy J. G.; Schmitz, Christoph; Sinner, Frank M.; Losen, Mario; Steinbusch, Harry W. M.; Frank, Hans-Georg; Martinez-Martinez, Pilar

2015-01-01

Aims The aim of the current study was to develop a method to detect peptide-linked nanoparticles in blood plasma. Materials & Methods A convenient enzyme linked immunosorbent assay (ELISA) was developed for the detection of peptides functionalized with biotin and fluorescein groups. As a proof of principle, polymerized pentafluorophenyl methacrylate nanoparticles linked to biotin-carboxyfluorescein labeled peptides were intravenously injected in Wistar rats. Serial blood plasma samples were analyzed by ELISA and by liquid chromatography mass spectrometry (LC/MS) technology. Results The ELISA based method for the detection of FITC labeled peptides had a detection limit of 1 ng/mL. We were able to accurately measure peptides bound to pentafluorophenyl methacrylate nanoparticles in blood plasma of rats, and similar results were obtained by LC/MS. Conclusions We detected FITC-labeled peptides on pentafluorophenyl methacrylate nanoparticles after injection in vivo. This method can be extended to detect nanoparticles with different chemical compositions. PMID:25996618

MuTRiG: a mixed signal Silicon Photomultiplier readout ASIC with high timing resolution and gigabit data link

NASA Astrophysics Data System (ADS)

Chen, H.; Briggl, K.; Eckert, P.; Harion, T.; Munwes, Y.; Shen, W.; Stankova, V.; Schultz-Coulon, H. C.

2017-01-01

MuTRiG is a mixed signal Silicon Photomultiplier readout ASIC designed in UMC 180 nm CMOS technology for precise timing and high event rate applications in high energy physics experiments and medical imaging. It is dedicated to the readout of the scintillating fiber detector and the scintillating tile detector of the Mu3e experiment. The MuTRiG chip extends the excellent timing performance of the STiCv3 chip with a fast digital readout for high rate applications. The high timing performance of the fully differential SiPM readout channels and 50 ps time binning TDCs are complemented by an upgraded digital readout logic and a 1.28 Gbps LVDS serial data link. The design of the chip and the characterization results of the analog front-end, TDC and the LVDS data link are presented.

The effects of link format and screen location on visual search of web pages.

PubMed

Ling, Jonathan; Van Schaik, Paul

2004-06-22

Navigation of web pages is of critical importance to the usability of web-based systems such as the World Wide Web and intranets. The primary means of navigation is through the use of hyperlinks. However, few studies have examined the impact of the presentation format of these links on visual search. The present study used a two-factor mixed measures design to investigate whether there was an effect of link format (plain text, underlined, bold, or bold and underlined) upon speed and accuracy of visual search and subjective measures in both the navigation and content areas of web pages. An effect of link format on speed of visual search for both hits and correct rejections was found. This effect was observed in the navigation and the content areas. Link format did not influence accuracy in either screen location. Participants showed highest preference for links that were in bold and underlined, regardless of screen area. These results are discussed in the context of visual search processes and design recommendations are given.

Recovery of high speed memory scanning after transient global amnesia: a case report.

PubMed

Okura, M; Tomotake, M; Mori, K; Ikuta, T

1996-12-01

We described the case of a 59 year old female with transient global amnesia (TGA) who had been examined neuropsychologically using Sternberg's paradigm and a random number generation (RNG) task on the following day, 1 week and 4 weeks after a TGA episode. The slope value of the linear function, a measure of cognitive memory scanning speed, decreased with time and showed a marked decrease 1 week after TGA, suggesting that the stage of serial and exhaustive scanning recovered within 1 week. The zero-intercept value, on the other hand, increased during 1 week but decreased 4 weeks later and was not related directly to recovery from TGA. The performance in RNG task improved 1 week later, but deteriorated 4 weeks after the episode. Such a change in RNG was in accordance with that of the zero-intercept value, predicting a relationship. It is concluded that the subclinical memory deficit, detected with these tasks, persisted longer than clinical recovery from TGA.

Evaluating the networking characteristics of the Cray XC-40 Intel Knights Landing-based Cori supercomputer at NERSC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doerfler, Douglas; Austin, Brian; Cook, Brandon

There are many potential issues associated with deploying the Intel Xeon Phi™ (code named Knights Landing [KNL]) manycore processor in a large-scale supercomputer. One in particular is the ability to fully utilize the high-speed communications network, given that the serial performance of a Xeon Phi TM core is a fraction of a Xeon®core. In this paper, we take a look at the trade-offs associated with allocating enough cores to fully utilize the Aries high-speed network versus cores dedicated to computation, e.g., the trade-off between MPI and OpenMP. In addition, we evaluate new features of Cray MPI in support of KNL,more » such as internode optimizations. We also evaluate one-sided programming models such as Unified Parallel C. We quantify the impact of the above trade-offs and features using a suite of National Energy Research Scientific Computing Center applications.« less

Precision Parameter Estimation and Machine Learning

NASA Astrophysics Data System (ADS)

Wandelt, Benjamin D.

2008-12-01

I discuss the strategy of ``Acceleration by Parallel Precomputation and Learning'' (AP-PLe) that can vastly accelerate parameter estimation in high-dimensional parameter spaces and costly likelihood functions, using trivially parallel computing to speed up sequential exploration of parameter space. This strategy combines the power of distributed computing with machine learning and Markov-Chain Monte Carlo techniques efficiently to explore a likelihood function, posterior distribution or χ2-surface. This strategy is particularly successful in cases where computing the likelihood is costly and the number of parameters is moderate or large. We apply this technique to two central problems in cosmology: the solution of the cosmological parameter estimation problem with sufficient accuracy for the Planck data using PICo; and the detailed calculation of cosmological helium and hydrogen recombination with RICO. Since the APPLe approach is designed to be able to use massively parallel resources to speed up problems that are inherently serial, we can bring the power of distributed computing to bear on parameter estimation problems. We have demonstrated this with the CosmologyatHome project.

The scientific data acquisition system of the GAMMA-400 space project

NASA Astrophysics Data System (ADS)

Bobkov, S. G.; Serdin, O. V.; Gorbunov, M. S.; Arkhangelskiy, A. I.; Topchiev, N. P.

2016-02-01

The description of scientific data acquisition system (SDAS) designed by SRISA for the GAMMA-400 space project is presented. We consider the problem of different level electronics unification: the set of reliable fault-tolerant integrated circuits fabricated on Silicon-on-Insulator 0.25 mkm CMOS technology and the high-speed interfaces and reliable modules used in the space instruments. The characteristics of reliable fault-tolerant very large scale integration (VLSI) technology designed by SRISA for the developing of computation systems for space applications are considered. The scalable net structure of SDAS based on Serial RapidIO interface including real-time operating system BAGET is described too.

Parallel auto-correlative statistics with VTK.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pebay, Philippe Pierre; Bennett, Janine Camille

2013-08-01

This report summarizes existing statistical engines in VTK and presents both the serial and parallel auto-correlative statistics engines. It is a sequel to [PT08, BPRT09b, PT09, BPT09, PT10] which studied the parallel descriptive, correlative, multi-correlative, principal component analysis, contingency, k-means, and order statistics engines. The ease of use of the new parallel auto-correlative statistics engine is illustrated by the means of C++ code snippets and algorithm verification is provided. This report justifies the design of the statistics engines with parallel scalability in mind, and provides scalability and speed-up analysis results for the autocorrelative statistics engine.

An automatic molecular beam microwave Fourier transform spectrometer

NASA Astrophysics Data System (ADS)

Andresen, U.; Dreizler, H.; Grabow, J.-U.; Stahl, W.

1990-12-01

The general setup of an automatic MB-MWFT spectrometer for use in the 4-18 GHz range and its software details are discussed. The experimental control and data handling are performed on a personal computer using an interactive program. The parameters of the MW source and the resonator are controlled via IEEE bus and several serial interface ports. The tuning and measuring processes are automated and the efficiency is increased if unknown spectra are to be scanned. As an example, the spectrum of carbonyl sulfide has been measured automatically. The spectrometer is superior to all other kinds of rotational spectroscopic methods in both speed and unambiguity.

Analog Signal Correlating Using an Analog-Based Signal Conditioning Front End

NASA Technical Reports Server (NTRS)

Prokop, Norman; Krasowski, Michael

2013-01-01

This innovation is capable of correlating two analog signals by using an analog-based signal conditioning front end to hard-limit the analog signals through adaptive thresholding into a binary bit stream, then performing the correlation using a Hamming "similarity" calculator function embedded in a one-bit digital correlator (OBDC). By converting the analog signal into a bit stream, the calculation of the correlation function is simplified, and less hardware resources are needed. This binary representation allows the hardware to move from a DSP where instructions are performed serially, into digital logic where calculations can be performed in parallel, greatly speeding up calculations.

Improvement of Janus Using Pegasus 1-Meter Resolution Database With a Transputer Network

DTIC Science & Technology

1994-03-01

Figure 4.9 shows the six jacks on the end of the HSI-card. Facing the back of the SPARC Station LINKO LINKI LINK2 LINK3 DOWN UP Figure 4.9: HSI-Card Link...shown in Figure 4.22. Facing the back of the Sun SPARC Station LINK0 LINKI LINK2 LINK3 DOWN UP "b Telephone Cable Facing the front of the Remote Tram...Holder LINKO LINKI LINK2 LINK3 DOWN UPI Figure 4.20: The Connection Between Sun SPARC Station and Remote Tram Holder 58 (3) Se.inu Up t• Link Speed

Using Link Disconnection Entropy Disorder to Detect Fast Moving Nodes in MANETs

PubMed Central

Palafox, Luis E.; Aguilar, Leocundo; Sanchez, Mauricio A.; Martinez, Luis G.

2016-01-01

Mobile ad-hoc networks (MANETs) are dynamic by nature; this dynamism comes from node mobility, traffic congestion, and other transmission conditions. Metrics to evaluate the effects of those conditions shine a light on node’s behavior in an ad-hoc network, helping to identify the node or nodes with better conditions of connection. In this paper, we propose a relative index to evaluate a single node reliability, based on the link disconnection entropy disorder using neighboring nodes as reference. Link disconnection entropy disorder is best used to identify fast moving nodes or nodes with unstable communications, this without the need of specialized sensors such as GPS. Several scenarios were studied to verify the index, measuring the effects of Speed and traffic density on the link disconnection entropy disorder. Packet delivery ratio is associated to the metric detecting a strong relationship, enabling the use of the link disconnection entropy disorder to evaluate the stability of a node to communicate with other nodes. To expand the utilization of the link entropy disorder, we identified nodes with higher speeds in network simulations just by using the link entropy disorder. PMID:27219671

Future ultra-speed tube-flight

NASA Astrophysics Data System (ADS)

Salter, Robert M.

1994-05-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Future ultra-speed tube-flight

NASA Technical Reports Server (NTRS)

Salter, Robert M.

1994-01-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Gender Interacts with Opioid Receptor Polymorphism A118G and Serotonin Receptor Polymorphism -1438 A/G on Speed-Dating Success.

PubMed

Wu, Karen; Chen, Chuansheng; Moyzis, Robert K; Greenberger, Ellen; Yu, Zhaoxia

2016-09-01

We examined an understudied but potentially important source of romantic attraction-genetics-using a speed-dating paradigm. The mu opioid receptor (OPRM1) polymorphism A118G (rs1799971) and the serotonin receptor (HTR2A) polymorphism -1438 A/G (rs6311) were studied because they have been implicated in social affiliation. Guided by the social role theory of mate selection and prior genetic evidence, we examined these polymorphisms' gender-specific associations with speed-dating success (i.e., date offers, mate desirability). A total of 262 single Asian Americans went on speed-dates with members of the opposite gender and completed interaction questionnaires about their partners. Consistent with our prediction, significant gender-by-genotype interactions were found for speed-dating success. Specifically, the minor variant of A118G (G-allele), which has been linked to submissiveness/social sensitivity, predicted greater speed-dating success for women, whereas the minor variant of -1438 A/G (G-allele), which has been linked to leadership/social dominance, predicted greater speed-dating success for men. For both polymorphisms, reverse "dampening" effects of minor variants were found for opposite-gender counterparts. These results support previous research on the importance of the opioid and serotonergic systems in social affiliation, indicating that their influence extends to dating success, with opposite, yet gender-norm consistent, effects for men and women.

Improving Control of Two Motor Controllers

NASA Technical Reports Server (NTRS)

Toland, Ronald W.

2004-01-01

A computer program controls motors that drive translation stages in a metrology system that consists of a pair of two-axis cathetometers. This program is specific to Compumotor Gemini (or equivalent) motors and the Compumotor 6K-series (or equivalent) motor controller. Relative to the software supplied with the controller, this program affords more capabilities and is easier to use. Written as a Virtual Instrument in the LabVIEW software system, the program presents an imitation control panel that the user can manipulate by use of a keyboard and mouse. There are three modes of operation: command, movement, and joystick. In command mode, single commands are sent to the controller for troubleshooting. In movement mode, distance, speed, and/or acceleration commands are sent to the controller. Position readouts from the motors and from position encoders on the translation stages are displayed in marked fields. At any time, the position readouts can be recorded in a file named by the user. In joystick mode, the program yields control of the motors to a joystick. The program sends commands to, and receives data from, the controller via a serial cable connection, using the serial-communication portion of the software supplied with the controller.

Reward Sensitivity and Waiting Impulsivity: Shift towards Reward Valuation away from Action Control

PubMed Central

Mechelmans, Daisy J; Strelchuk, Daniela; Doñamayor, Nuria; Banca, Paula; Robbins, Trevor W; Baek, Kwangyeol

2017-01-01

Abstract Background Impulsivity and reward expectancy are commonly interrelated. Waiting impulsivity, measured using the rodent 5-Choice Serial Reaction Time task, predicts compulsive cocaine seeking and sign (or cue) tracking. Here, we assess human waiting impulsivity using a novel translational task, the 4-Choice Serial Reaction Time task, and the relationship with reward cues. Methods Healthy volunteers (n=29) performed the monetary incentive delay task as a functional MRI study where subjects observe a cue predicting reward (cue) and wait to respond for high (£5), low (£1), or no reward. Waiting impulsivity was tested with the 4-Choice Serial Reaction Time task. Results For high reward prospects (£5, no reward), greater waiting impulsivity on the 4-CSRT correlated with greater medial orbitofrontal cortex and lower supplementary motor area activity to cues. In response to high reward cues, greater waiting impulsivity was associated with greater subthalamic nucleus connectivity with orbitofrontal cortex and greater subgenual cingulate connectivity with anterior insula, but decreased connectivity with regions implicated in action selection and preparation. Conclusion These findings highlight a shift towards regions implicated in reward valuation and a shift towards compulsivity away from higher level motor preparation and action selection and response. We highlight the role of reward sensitivity and impulsivity, mechanisms potentially linking human waiting impulsivity with incentive approach and compulsivity, theories highly relevant to disorders of addiction. PMID:29020291

Three-dimensional reconstruction of root cells and interdental cells in the rat inner ear by serial section scanning electron microscopy.

PubMed

Shodo, Ryusuke; Hayatsu, Manabu; Koga, Daisuke; Horii, Arata; Ushiki, Tatsuo

2017-01-01

In the cochlea, a high K + environment in the endolymph is essential for the maintenance of normal hearing function, and the transport of K + ions through gap junctions of the cochlear epithelium is thought to play an important role in endolymphatic homeostasis. The aim of the present study was to demonstrate the three-dimensional (3D) ultrastructure of spiral ligament root cells and interdental cells, which are located at both ends of the gap junction system of the cochlea epithelium. Serial semi-thin sections of plastic-embedded rat cochlea were mounted on glass slides, stained with uranyl acetate and lead citrate, and observed by scanning electron microscopy (SEM) using the backscattered electron (BSE) mode. 3D reconstruction of BSE images of serial sections revealed that the root cells were linked together to form a branched structure like an elaborate "tree root" in the spiral ligament. The interdental cells were also connected to each other, forming a comb-shaped cellular network with a number of cellular strands in the spiral limbus. Furthermore, TEM studies of ultra-thin sections revealed the rich presence of gap junctions in both root cells and interdental cells. These findings suggest the possibility that both root cells and interdental cells contribute to K + circulation as the end portion of the epithelial cell gap junction system of the cochlea.

Networking via wireless bridge produces greater speed and flexibility, lowers cost.

PubMed

1998-10-01

Wireless computer networking. Computer connectivity is essential in today's high-tech health care industry. But telephone lines aren't fast enough, and high-speed connections like T-1 lines are costly. Read about an Ohio community hospital that installed a wireless network "bridge" to connect buildings that are miles apart, creating a reliable high-speed link that costs one-tenth of a T-1 line.

Low cost open data acquisition system for biomedical applications

NASA Astrophysics Data System (ADS)

Zabolotny, Wojciech M.; Laniewski-Wollk, Przemyslaw; Zaworski, Wojciech

2005-09-01

In the biomedical applications it is often necessary to collect measurement data from different devices. It is relatively easy, if the devices are equipped with a MIB or Ethernet interface, however often they feature only the asynchronous serial link, and sometimes the measured values are available only as the analog signals. The system presented in the paper is a low cost alternative to commercially available data acquisition systems. The hardware and software architecture of the system is fully open, so it is possible to customize it for particular needs. The presented system offers various possibilities to connect it to the computer based data processing unit - e.g. using the USB or Ethernet ports. Both interfaces allow also to use many such systems in parallel to increase amount of serial and analog inputs. The open source software used in the system makes possible to process the acquired data with standard tools like MATLAB, Scilab or Octave, or with a dedicated, user supplied application.

Serial foodborne norovirus outbreaks associated with multiple genotypes.

PubMed

Huang, Jianwei; Xu, Xuerong; Weng, Qinyun; Hong, Huarong; Guo, Zhinan; He, Shuizhen; Niu, Jianjun

2013-01-01

Noroviruses (NoV) have been recognized as an important pathogen associated with acute gastroenteritis worldwide during the past three decades. In the spring of 2012, a series of foodborne outbreaks in tourist groups were reported to Xiamen Center for Disease Control and Prevention, Xiamen, Fujian province, China. Among a total of 268 tourists in 7 groups, the prevalence rate of acute gastroenteritis was 16.0% (43/268). Twenty-three feces or anal swabs were collected for laboratory tests of causative agents, no bacterial pathogen was identified, while 22 of them were positive for NoV RNA. In addition, thirteen NoV fragments were recovered from positive specimens and sequenced, belonging to five genotypes such as GI.3, GI.4, GII.4, GII.6, and GII.14, respectively. However, NoV fragments obtained from locally infected patients showed distinct genotypes. Therefore, epidemiological investigation and laboratory analyses demonstrated that the serial foodborne NoV outbreaks in tourists were co-infection of multiple genotypes induced acute gastroenteritis linked to a restaurant.

The role of fantasy in a serial sexual offender: a brief review of the literature and a case report.

PubMed

Carabellese, Felice; Maniglio, Roberto; Greco, Oronzo; Catanesi, Roberto

2011-01-01

Extensive research has attempted to elucidate the role of fantasy in sexual offending. In this paper, the authors summarize the main results of the literature, especially the contents, themes, dynamics, etiopathogenesis, and potential functions of fantasy in sexual offending. Further, the authors analyze the case of a serial sexual offender who assaulted 39 women. The forensic-psychiatric assessment revealed that his fantasies of forced sex, sexual coercion, and dominance, which were linked to narcissistic personality organization and functioning, were the primary drive mechanism in his crimes, because he imagined himself in the role of the aggressor, identified with the power associated with the role of perpetrator, and was sexually aroused by such images of omnipotent control of the victim. In conclusions, the authors suggest that fantasies of sexual aggression, coercion, and dominance of women may stimulate grandiosity and omnipotence and, in a minority of cases, may lead to sexual offending. © 2010 American Academy of Forensic Sciences.

Serial Foodborne Norovirus Outbreaks Associated with Multiple Genotypes

PubMed Central

Huang, Jianwei; Xu, Xuerong; Weng, Qinyun; Hong, Huarong; Guo, Zhinan; He, Shuizhen; Niu, Jianjun

2013-01-01

Noroviruses (NoV) have been recognized as an important pathogen associated with acute gastroenteritis worldwide during the past three decades. In the spring of 2012, a series of foodborne outbreaks in tourist groups were reported to Xiamen Center for Disease Control and Prevention, Xiamen, Fujian province, China. Among a total of 268 tourists in 7 groups, the prevalence rate of acute gastroenteritis was 16.0% (43/268). Twenty-three feces or anal swabs were collected for laboratory tests of causative agents, no bacterial pathogen was identified, while 22 of them were positive for NoV RNA. In addition, thirteen NoV fragments were recovered from positive specimens and sequenced, belonging to five genotypes such as GI.3, GI.4, GII.4, GII.6, and GII.14, respectively. However, NoV fragments obtained from locally infected patients showed distinct genotypes. Therefore, epidemiological investigation and laboratory analyses demonstrated that the serial foodborne NoV outbreaks in tourists were co-infection of multiple genotypes induced acute gastroenteritis linked to a restaurant. PMID:23667602

[Spanish drivers' beliefs about speed. Speeding is a major issue of road safety].

PubMed

Montoro González, Luis; Roca Ruiz, Javier; Lucas-Alba, Antonio

2010-11-01

Extending and updating our knowledge concerning drivers' motivational and cognitive processes is of essential importance if we are to apply policies with long-lasting effects. This study presents data from a representative national survey analyzing the Spanish drivers' beliefs about speed, the risks of speeding, the degree of violation of speed-limits and the reasons for speeding. Results indicate that Spanish drivers rate speeding as a serious offence, yet not among the most dangerous ones. All in all, they claim to comply mostly with the speed limits. However, some interesting violation patterns emerge: observance is lower for generic speed limits according to road type (vs. specific limits shown by certain road signs), and particularly in motorways (vs. single carriageways and urban areas). Risk perception and reasons for speeding emerge as the main factors predicting the levels of speed violations reported. Results suggest that any effective intervention strategy should consider such factors, namely the link between speed, road safety, and drivers' specific reasons for speeding.

X-15 test pilots - Thompson, Dana, and McKay

NASA Technical Reports Server (NTRS)

1966-01-01

NASA pilots Milton O. Thompson, William H. 'Bill' Dana, and John B. 'Jack' McKay are seen here in front of the #2 X-15 (56-6671) rocket-powered research aircraft. Among them, the three NASA research pilots made 59 flights in the X-15 (14 for Thompson, 16 for Dana, and 29 for McKay). The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of rated thrust (actual thrust reportedly climbed to 60,000 lb). North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used: a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years--June 1959 to Oct. 1968--and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft (over 67 mi) in a program to investigate all aspects of piloted hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

X-15 #2 just after launch

NASA Technical Reports Server (NTRS)

1960-01-01

The X-15 #2 (56-6671) launches away from the B-52 mothership with its rocket engine ignited. The white patches near the middle of the ship are frost from the liquid oxygen used in the propulsion system, although very cold liquid nitrogen was also used to cool the payload bay, cockpit, windshields, and nose. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of rated thrust (actual thrust reportedly climbed to 60,000 lb). North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used: a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years--June 1959 to Oct. 1968--and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft (over 67 mi) in a program to investigate all aspects of piloted hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

X-15 #3 pedestal-mounted full-scale replica covered in snow

NASA Technical Reports Server (NTRS)

1997-01-01

The full scale mock-up of X-15 #3 was installed September 1995 at the NASA Dryden Flight Research Center, Edwards, California. The original X-15 #3, serial number 56-6672, was destroyed on 15 November 1967, in a crash that also fatally injured pilot Maj. Michael J. Adams. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. Parts of the crashed X-15-3, recovered in 1992 by Peter Merlin and Tony Moore (The X-Hunters) are on display at the Air Force Flight Test Center Museum at Edwards. The canopy from the X-15-3, recovered during the original search in 1967, is displayed at the San Diego Aerospace Museum, San Diego, California.

X-15 landing on lakebed

NASA Technical Reports Server (NTRS)

1961-01-01

The North American X-15 settles to the lakebed after a research flight from what is now the NASA Dryden Flight Research Center, Edwards, California. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of rated thrust (actual thrust reportedly climbed to 60,000 lb). North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used: a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years--June 1959 to Oct. 1968--and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft (over 67 mi) in a program to investigate all aspects of piloted hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

X-15 cockpit

NASA Technical Reports Server (NTRS)

1963-01-01

This photo shows the X-15 cockpit. The X-15 was unique for many reasons, including the fact that it had two types of controls for the pilot. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wing provided roll control. The conventional aerodynamic controls used a stick, located in the middle of the floor, and pedals. The reaction control system used a side arm controller, seen in this photo on the left. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

SR-71B - in flight over snow-capped mountains

NASA Technical Reports Server (NTRS)

1995-01-01

Dryden's SR-71B, NASA 831, slices across the snowy southern Sierra Nevada Mountains of California after being refueled by an Air Force Flight Test Center tanker during a recent flight. The Mach 3 aircraft, on loan to NASA by the U.S. Air Force, were flown by the Dryden Flight Research Center, Edwards, California, during the decade of the 1990s as testbeds for high-speed, high-altitude aeronautical research. Capable of flying more than 2200 mph and at altitudes of over 80,000 feet, they were excellent platforms for research and experiments in aerodynamics, propulsion, structures, thermal protection materials, atmospheric studies, and sonic boom characterization. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground much like sharp thunderclaps when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startle affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Dryden has had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+ or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Pilot Stephen (Steve) D. Ishmael

NASA Technical Reports Server (NTRS)

1992-01-01

NASA research pilot Stephen D. Ishmael is pictured here in front of an SR-71 Blackbird on the ramp at the Dryden Flight Research Center, Edwards, California. Ishmael was one of two NASA research pilots assigned to the SR-71 high speed research program in the early 1990s at NASA's Dryden Flight Research Facility (redesignated the Dryden Flight Research Center in 1994), Edwards, California. Ishmael became a NASA research pilot in 1977. Data from the SR-71 program will be used to aid designers of future supersonic aircraft and propulsion systems. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Pilot Rogers E. Smith

NASA Technical Reports Server (NTRS)

1992-01-01

Research pilot Rogers E. Smith is shown here in front of the SR-71 Blackbird he flew for NASA. Rogers was one of the two original NASA research pilots assigned to the SR-71 high speed research program at NASA's Ames-Dryden Flight Research Facility (later, Dryden Flight Research Center, Edwards, California. Smith has been a NASA research pilot at Dryden since 1982. Data from the SR-71 program will be used to aid designers of future supersonic aircraft and propulsion systems. The SR-71 is capable of flying more than 2200 mph (Mach 3+) and at altitudes of over 80,000 feet. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

High frequency optical communications; Proceedings of the Meeting, Cambridge, MA, Sept. 23, 24, 1986

NASA Astrophysics Data System (ADS)

Ramer, O. Glenn; Sierak, Paul

Topics discussed in this volume include systems and applications, detectors, sources, and coherent communications. Papers are presented on RF fiber optic links for avionics applications, fiber optics and optoelectronics for radar and electronic warfare applications, symmetric coplanar electrodes for high-speed Ti:LiNbO3 devices, and surface wave electrooptic modulator. Attention is given to X-band RF fiber-optic links, fiber-optic links for microwave signal transmission, GaAs monolithic receiver and laser driver for GHz transmission rates, and monolithically integrable high-speed photodetectors. Additional papers are on irregular and chaotic behavior of semiconductor lasers under modulation, high-frequency laser package for microwave optical communications, receiver modeling for coherent light wave communications, and polarization sensors and controllers for coherent optical communication systems.

Trade-off between speed and cost in shortcuts to adiabaticity

NASA Astrophysics Data System (ADS)

Campbell, Steve

Recent years have witnessed a surge of interest in the study of thermal nano-machines that are capable of converting disordered forms of energy into useful work. It has been shown for both classical and quantum systems that external drivings can allow a system to evolve adiabatically even when driven in finite time, a technique commonly known as shortcuts to adiabaticity. It was suggested to use such external drivings to render the unitary processes of a thermodynamic cycle quantum adiabatic, while being performed in finite time. However, implementing an additional external driving requires resources that should be accounted for. Furthermore, and in line with natural intuition, these transformations should not be achievable in arbitrarily short times. First, we will present a computable measure of the cost of a shortcut to adiabaticity. Using this, we then examine the speed with which a quantum system can be driven. As a main result, we will establish a rigorous link between this speed, the quantum speed limit, and the (energetic) cost of implementing such a shortcut to adiabaticity. Interestingly, this link elucidates a trade-off between speed and cost, namely that instantaneous manipulation is impossible as it requires an infinite cost.

Linking molecular level chemistry to macroscopic combustion behavior for nano-energetic materials with halogen containing oxides.

PubMed

Farley, Cory W; Pantoya, Michelle L; Losada, Martin; Chaudhuri, Santanu

2013-08-21

Coupling molecular scale reaction kinetics with macroscopic combustion behavior is critical to understanding the influences of intermediate chemistry on energy propagation, yet bridging this multi-scale gap is challenging. This study integrates ab initio quantum chemical calculations and condensed phase density functional theory to elucidate factors contributing to experimentally measured high flame speeds (i.e., >900 m∕s) associated with halogen based energetic composites, such as aluminum (Al) and iodine pentoxide (I2O5). Experiments show a direct correlation between apparent activation energy and flame speed suggesting that flame speed is directly influenced by chemical kinetics. Toward this end, the first principle simulations resolve key exothermic surface and intermediate chemistries contributing toward the kinetics that promote high flame speeds. Linking molecular level exothermicity to macroscopic experimental investigations provides insight into the unique role of the alumina oxide shell passivating aluminum particles. In the case of Al reacting with I2O5, the alumina shell promotes exothermic surface chemistries that reduce activation energy and increase flame speed. This finding is in contrast to Al reaction with metal oxides that show the alumina shell does not participate exothermically in the reaction.

Highball: A high speed, reserved-access, wide area network

NASA Technical Reports Server (NTRS)

Mills, David L.; Boncelet, Charles G.; Elias, John G.; Schragger, Paul A.; Jackson, Alden W.

1990-01-01

A network architecture called Highball and a preliminary design for a prototype, wide-area data network designed to operate at speeds of 1 Gbps and beyond are described. It is intended for applications requiring high speed burst transmissions where some latency between requesting a transmission and granting the request can be anticipated and tolerated. Examples include real-time video and disk-disk transfers, national filestore access, remote sensing, and similar applications. The network nodes include an intelligent crossbar switch, but have no buffering capabilities; thus, data must be queued at the end nodes. There are no restrictions on the network topology, link speeds, or end-end protocols. The end system, nodes, and links can operate at any speed up to the limits imposed by the physical facilities. An overview of an initial design approach is presented and is intended as a benchmark upon which a detailed design can be developed. It describes the network architecture and proposed access protocols, as well as functional descriptions of the hardware and software components that could be used in a prototype implementation. It concludes with a discussion of additional issues to be resolved in continuing stages of this project.

Is the scaling of swim speed in sharks driven by metabolism?

PubMed Central

Jacoby, David M. P.; Siriwat, Penthai; Freeman, Robin; Carbone, Chris

2015-01-01

The movement rates of sharks are intrinsically linked to foraging ecology, predator–prey dynamics and wider ecosystem functioning in marine systems. During ram ventilation, however, shark movement rates are linked not only to ecological parameters, but also to physiology, as minimum speeds are required to provide sufficient water flow across the gills to maintain metabolism. We develop a geometric model predicting a positive scaling relationship between swim speeds in relation to body size and ultimately shark metabolism, taking into account estimates for the scaling of gill dimensions. Empirical data from 64 studies (26 species) were compiled to test our model while controlling for the influence of phylogenetic similarity between related species. Our model predictions were found to closely resemble the observed relationships from tracked sharks, providing a means to infer mobility in particularly intractable species. PMID:26631246

The high speed interconnect system architecture and operation

NASA Astrophysics Data System (ADS)

Anderson, Steven C.

The design and operation of a fiber-optic high-speed interconnect system (HSIS) being developed to meet the requirements of future avionics and flight-control hardware with distributed-system architectures are discussed. The HSIS is intended for 100-Mb/s operation of a local-area network with up to 256 stations. It comprises a bus transmission system (passive star couplers and linear media linked by active elements) and network interface units (NIUs). Each NIU is designed to perform the physical, data link, network, and transport functions defined by the ISO OSI Basic Reference Model (1982 and 1983) and incorporates a fiber-optic transceiver, a high-speed protocol based on the SAE AE-9B linear token-passing data bus (1986), and a specialized application interface unit. The operating modes and capabilities of HSIS are described in detail and illustrated with diagrams.

16,000-rpm Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, John S; Burress, Timothy A; Lee, Seong T

2008-01-01

This paper introduces a high speed brushless field excitation (BFE) machine that offers high torque per ampere (A) per core length at low speed and weakened flux at high speed. Lower core losses at high speeds, are attained by reducing the field excitation. Safety and reliability are increased by weakening the field when a winding short-circuit fault occurs. For a high-speed motor the bridges that link the rotor punching segments together must be thickened for mechanical integrity; BFE can ensure sufficient rotor flux when needed. Projected efficiency map including losses of the excitation coils confirms the advantage of this technology.

Fiber Optic Wink-around Speed of Light Experiment.

ERIC Educational Resources Information Center

Blackburn, James A.

1980-01-01

Describes an experiment in which a recycling oscillator has been designed having a fiber optic data link that closes the loop. Outlines the use of this wink-around system to determine the speed of light and suggests additional application for measuring integrated circuit propagation delays to subnanosecond resolution. (GS)

Body shape, burst speed and escape behavior of larval anurans

Treesearch

Gage H. Dayton; Daniel Saenz; Kristen A. Baum; R. Brian Langerhans; Thomas J. DeWitt

2005-01-01

Variation in behavior, morphology and life history traits of larval anurans across predator gradients, and consequences of that variation, have been abundantly studied. Yet the functional link between morphology and burst-swimming speed is largely unknown. We conducted experiments with two divergent species of anurans, Scaphiopus holbrookii and

X-15 #3 with test pilot Bill Dana

NASA Technical Reports Server (NTRS)

1967-01-01

NASA research pilot Bill Dana is seen here next to the X-15 #3 (56-6672) rocket-powered aircraft after a flight. William H. Dana is Chief Engineer at NASA's Dryden Flight Research Center, Edwards, California. Formerly an aerospace research pilot at Dryden, Dana flew the F-15 HIDEC research aircraft and the Advanced Fighter Technology Integration/F-16 aircraft. Dana flew the famed X-15 research airplane 16 times, reaching a top speed of 3,897 miles per hour and a peak altitude of 306,900 feet (over 58 miles high). The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation built three X-15 aircraft for the program. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio.X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

X-15 mounted to B-52 mothership pylon - preparation for an attempt at two X-15 launches in one day

NASA Technical Reports Server (NTRS)

1960-01-01

This photo shows one of the four attempts NASA made at launching two X-15 aircraft in one day. This attempt occurred November 4, 1960. None of the four attempts was successful, although one of the two aircraft involved in each attempt usually made a research flight. In this case, Air Force pilot Robert A. Rushworth flew X-15 #1 on its 16th flight to a speed of Mach 1.95 and an altitude of 48,900 feet. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of rated thrust (actual thrust reportedly climbed to 60,000 lb). North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used: a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years--June 1959 to Oct. 1968--and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft (over 67 mi) in a program to investigate all aspects of piloted hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

X-15A-2 with full-scale ablative coating (pink X-15) in Building 4821

NASA Technical Reports Server (NTRS)

1967-01-01

In June 1967, the X-15A-2 rocket-powered research aircraft received a full-scale ablative coating to protect the craft from the high temperatures associated with hypersonic flight (above Mach 5). This pink eraser-like substance, applied to the X-15A-2 aircraft (56-6671), was then covered with a white sealant coat before flight. This coating would help the #2 aircraft reach the record speed of 4,520 mph (Mach 6.7). The basic X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. However, the X-15A-2 had been elongated to 52 ft 5 in. Like the other two X-15s, it was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

X-15A-2 with full scale ablative coating (pink X-15) on NASA ramp

NASA Technical Reports Server (NTRS)

1967-01-01

In June 1967, the X-15A-2 rocket powered research aircraft received a full-scale ablative coating to protect the craft from the high temperatures associated with supersonic flight. This pink eraser-like substance, applied to the #2 aircraft (56-6671), was then covered with a white sealant coat before flight. This coating would help the #2 aircraft reach the record speed of 4,520 mph (Mach 6.7). The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. However, the X-15A-2 had been elongated to 52 ft 5 in. Like the other two X-15s, it was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of piloted hypersonic flight. Information gained fromthe highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo piloted spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J Adams.

X-15 with test pilot Bill Dana

NASA Technical Reports Server (NTRS)

1966-01-01

NASA research pilot Bill Dana is seen here next to the X-15 #3 rocket-powered aircraft after a flight. William H. Dana is Chief Engineer at NASA's Dryden Flight Research Center, Edwards, California. Formerly an aerospace research pilot at Dryden, Dana flew the F-15 HiDEC research aircraft and the Advanced Fighter Technology Integration/F-16 aircraft. Dana flew the famed X-15 research airplane 16 times, reaching a top speed of 3,897 miles per hour and a peak altitude of 310,000 feet (almost 59 miles high). The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow on program used the aircraft as a testbed to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. The X-15 was a rocket-powered aircraft 50 ft long with a wingspan of 22 ft. It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was capable of developing 57,000 lb of thrust. North American Aviation made 3 X-15 aircraft for the program. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and canted horizontal surfaces on the tail to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. The X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

[Information processing speed and influential factors in multiple sclerosis].

PubMed

Zhang, M L; Xu, E H; Dong, H Q; Zhang, J W

2016-04-19

To study the information processing speed and the influential factors in multiple sclerosis (MS) patients. A total of 36 patients with relapsing-remitting MS (RRMS), 21 patients with secondary progressive MS (SPMS), and 50 healthy control subjects from Xuanwu Hospital of Capital Medical University between April 2010 and April 2012 were included into this cross-sectional study.Neuropsychological tests was conducted after the disease had been stable for 8 weeks, including information processing speed, memory, executive functions, language and visual perception.Correlation between information processing speed and depression, fatigue, Expanded Disability Status Scale (EDSS) were studied. (1)MS patient groups demonstrated cognitive deficits compared to healthy controls.The Symbol Digit Modalities Test (SDMT) (control group 57±12; RRMS group 46±17; SPMS group 35±10, P<0.05) and Paced Auditory Serial Addition Task (PASAT) (control group 85±18; RRMS group 77±20; SPMS group 57±20, P<0.05) impaired most.SPMS patients were more affected compared to patients with RRMS subtypes, and these differences were attenuated after control for physical disability level as measured by the EDSS scores.MS patients, especially SPMS subtype, were more severely impaired than control group in the verbal learning test, verbal fluency, Stroop C test planning time, while visual-spatial function and visual memory were relatively reserved in MS patients.(2) According to the Pearson univariate correlation analysis, age, depression, EDSS scores and fatigue were related with PASAT and SDMT tests (r=-0.41--0.61, P<0.05). Depression significantly affected the speed of information processing (P<0.05). Impairment of information processing speed, verbal memory and executive functioning are seen in MS patients, especially in SPMS subtype, while visual-spatial function is relatively reserved.Age, white matter change scales, EDSS scores, depression are negatively associated with information processing speed.

Multiple running speed signals in medial entorhinal cortex

PubMed Central

Hinman, James R.; Brandon, Mark P.; Climer, Jason R.; Chapman, G. William; Hasselmo, Michael E.

2016-01-01

Grid cells in medial entorhinal cortex (MEC) can be modeled using oscillatory interference or attractor dynamic mechanisms that perform path integration, a computation requiring information about running direction and speed. The two classes of computational models often use either an oscillatory frequency or a firing rate that increases as a function of running speed. Yet it is currently not known whether these are two manifestations of the same speed signal or dissociable signals with potentially different anatomical substrates. We examined coding of running speed in MEC and identified these two speed signals to be independent of each other within individual neurons. The medial septum (MS) is strongly linked to locomotor behavior and removal of MS input resulted in strengthening of the firing rate speed signal, while decreasing the strength of the oscillatory speed signal. Thus two speed signals are present in MEC that are differentially affected by disrupted MS input. PMID:27427460

Correlation of cycles in Lava Lake motion and degassing at Erebus Volcano, Antarctica

NASA Astrophysics Data System (ADS)

Peters, Nial; Oppenheimer, Clive; Killingsworth, Drea Rae; Frechette, Jed; Kyle, Philip

2014-08-01

Several studies at Erebus volcano have recorded pulsatory behavior in many of the observable properties of its active lava lake. A strong correlation between the variations in surface speed of the lake and the composition of gas emitted has previously been noted. While previous studies have shown that the SO2 flux and the surface elevation exhibit pulsatory behavior with a similar period to that of the surface speed and gas composition, suggesting they are linked, a lack of overlap between the different measurements has prevented direct comparisons from being made. Using high time-resolution measurements of surface elevation, surface speed, gas composition, and SO2 flux, we demonstrate for the first time an unambiguous link between the cyclic behavior in each of these properties. We also show that the variation in gas composition may be explained by a subtle change in oxygen fugacity. The cycles are found to be in-phase with each other, with a small but consistent lag of 1-3 min between the peaks in surface elevation and surface speed. Explosive events are found to have no observable effect on the pulsatory behavior beyond the ˜5 min period required for lake refill. The close correspondences between the varying lake surface motion, gas flux and composition, and modeled oxygen fugacity suggest strong links between magma degassing, redox change, and the fluid dynamics of the shallow magmatic system.

Oxidative Stress, Motor Abilities, and Behavioral Adjustment in Children Treated for Acute Lymphoblastic Leukemia.

PubMed

Hockenberry, Marilyn J; Krull, Kevin R; Insel, Kathleen C; Harris, Lynnette L; Gundy, Patricia M; Adkins, Kristin B; Pasvogel, Alice E; Taylor, Olga A; Koerner, Kari M; Montgomery, David W; Ross, Adam K; Hill, Adam; Moore, Ida M

2015-09-01

To examine associations among oxidative stress, fine and visual-motor abilities, and behavioral adjustment in children receiving chemotherapy for acute lymphoblastic leukemia (ALL)
. A prospective, repeated-measures design
. Two pediatric oncology settings in the southwestern United States. 89 children with ALL were followed from diagnosis to the end of chemotherapy. Serial cerebrospinal fluid samples were collected during scheduled lumbar punctures and analyzed for oxidative stress biomarkers. Children completed fine motor dexterity, visual processing speed, and visual-motor integration measures at three time points. Parents completed child behavior ratings at the same times. Oxidative stress, fine motor dexterity, visual processing, visual-motor integration, and behavioral adjustment
. Children with ALL had below-average fine motor dexterity, visual processing speed, and visual-motor integration following the induction phase of ALL therapy. By end of therapy, visual processing speed normalized, and fine motor dexterity and visual-motor integration remained below average. Oxidative stress measures correlated with fine motor dexterity and visual-motor integration. Decreased motor functioning was associated with increased hyperactivity and anxiety
. Oxidative stress occurs following chemo-therapy for childhood ALL and is related to impaired fine motor skills and visual symptoms
. Early intervention should be considered to prevent fine motor and visual-spatial deficits, as well as behavioral problems.

Demonstration of optical computing logics based on binary decision diagram.

PubMed

Lin, Shiyun; Ishikawa, Yasuhiko; Wada, Kazumi

2012-01-16

Optical circuits are low power consumption and fast speed alternatives for the current information processing based on transistor circuits. However, because of no transistor function available in optics, the architecture for optical computing should be chosen that optics prefers. One of which is Binary Decision Diagram (BDD), where signal is processed by sending an optical signal from the root through a serial of switching nodes to the leaf (terminal). Speed of optical computing is limited by either transmission time of optical signals from the root to the leaf or switching time of a node. We have designed and experimentally demonstrated 1-bit and 2-bit adders based on the BDD architecture. The switching nodes are silicon ring resonators with a modulation depth of 10 dB and the states are changed by the plasma dispersion effect. The quality, Q of the rings designed is 1500, which allows fast transmission of signal, e.g., 1.3 ps calculated by a photon escaping time. A total processing time is thus analyzed to be ~9 ps for a 2-bit adder and would scales linearly with the number of bit. It is two orders of magnitude faster than the conventional CMOS circuitry, ~ns scale of delay. The presented results show the potential of fast speed optical computing circuits.

Splitting attention reduces temporal resolution from 7 Hz for tracking one object to <3 Hz when tracking three.

PubMed

Holcombe, Alex O; Chen, Wei-Ying

2013-01-09

Overall performance when tracking moving targets is known to be poorer for larger numbers of targets, but the specific effect on tracking's temporal resolution has never been investigated. We document a broad range of display parameters for which visual tracking is limited by temporal frequency (the interval between when a target is at each location and a distracter moves in and replaces it) rather than by object speed. We tested tracking of one, two, and three moving targets while the eyes remained fixed. Variation of the number of distracters and their speed revealed both speed limits and temporal frequency limits on tracking. The temporal frequency limit fell from 7 Hz with one target to 4 Hz with two targets and 2.6 Hz with three targets. The large size of this performance decrease implies that in the two-target condition participants would have done better by tracking only one of the two targets and ignoring the other. These effects are predicted by serial models involving a single tracking focus that must switch among the targets, sampling the position of only one target at a time. If parallel processing theories are to explain why dividing the tracking resource reduces temporal resolution so markedly, supplemental assumptions will be required.

A high speed telemetry data link for an autonomous roving vehicle

NASA Technical Reports Server (NTRS)

Cipolle, D. J.

1980-01-01

A data link system used on a prototype autonomous roving vehicle is described. This system provides a means of acquiring, formatting, and transmitting information on board the vehicle to a controlling computer. Included is a statement of requirements and the design philosophy. Additionally, interfacing with the rover systems is discussed, along with the overall performance of the telemetry link.

Fuzzy logic control of an AGV

NASA Astrophysics Data System (ADS)

Kelkar, Nikhal; Samu, Tayib; Hall, Ernest L.

1997-09-01

Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of a modular autonomous mobile robot controller. The controller incorporates a fuzzy logic approach for steering and speed control, a neuro-fuzzy approach for ultrasound sensing (not discussed in this paper) and an overall expert system. The advantages of a modular system are related to portability and transportability, i.e. any vehicle can become autonomous with minimal modifications. A mobile robot test-bed has been constructed using a golf cart base. This cart has full speed control with guidance provided by a vision system and obstacle avoidance using ultrasonic sensors. The speed and steering fuzzy logic controller is supervised by a 486 computer through a multi-axis motion controller. The obstacle avoidance system is based on a micro-controller interfaced with six ultrasonic transducers. This micro- controller independently handles all timing and distance calculations and sends a steering angle correction back to the computer via the serial line. This design yields a portable independent system in which high speed computer communication is not necessary. Vision guidance is accomplished with a CCD camera with a zoom lens. The data is collected by a vision tracking device that transmits the X, Y coordinates of the lane marker to the control computer. Simulation and testing of these systems yielded promising results. This design, in its modularity, creates a portable autonomous fuzzy logic controller applicable to any mobile vehicle with only minor adaptations.

A transient FETI methodology for large-scale parallel implicit computations in structural mechanics

NASA Technical Reports Server (NTRS)

Farhat, Charbel; Crivelli, Luis; Roux, Francois-Xavier

1992-01-01

Explicit codes are often used to simulate the nonlinear dynamics of large-scale structural systems, even for low frequency response, because the storage and CPU requirements entailed by the repeated factorizations traditionally found in implicit codes rapidly overwhelm the available computing resources. With the advent of parallel processing, this trend is accelerating because explicit schemes are also easier to parallelize than implicit ones. However, the time step restriction imposed by the Courant stability condition on all explicit schemes cannot yet -- and perhaps will never -- be offset by the speed of parallel hardware. Therefore, it is essential to develop efficient and robust alternatives to direct methods that are also amenable to massively parallel processing because implicit codes using unconditionally stable time-integration algorithms are computationally more efficient when simulating low-frequency dynamics. Here we present a domain decomposition method for implicit schemes that requires significantly less storage than factorization algorithms, that is several times faster than other popular direct and iterative methods, that can be easily implemented on both shared and local memory parallel processors, and that is both computationally and communication-wise efficient. The proposed transient domain decomposition method is an extension of the method of Finite Element Tearing and Interconnecting (FETI) developed by Farhat and Roux for the solution of static problems. Serial and parallel performance results on the CRAY Y-MP/8 and the iPSC-860/128 systems are reported and analyzed for realistic structural dynamics problems. These results establish the superiority of the FETI method over both the serial/parallel conjugate gradient algorithm with diagonal scaling and the serial/parallel direct method, and contrast the computational power of the iPSC-860/128 parallel processor with that of the CRAY Y-MP/8 system.

Real-time differential GPS/GLONASS trials in Europe using all-in-view 20-channel receivers

NASA Astrophysics Data System (ADS)

Capaccio, S.; Lowe, D.; Walsh, D. M. A.; Daly, P.

Following the initial development of 20-channel, all-in-view Global Navigation Satellite System (GNSS), GPS/GLONASS/Inmarsat-3, receivers at the Institute of Satellite Navigation (ISN), University of Leeds, a modification programme has been undertaken to allow real-time differential corrections to be sent from one 20-channel receiver to another identical receiver using a serial link between them. The differential correction software incorporates the RTCM SC-104 and RTCA DO-217 format developed specifically for GPS and adjusted by the ISN to allow simultaneous GLONASS operation.After successful laboratory testing, real-time differential GNSS tests were successfully completed in static mode between Aberdeen and Leeds via the SkyFix differential data-link, and in dynamic mode at DTEO Boscombe Down using a C-band data-link between the ground and a receiver on board the DRA BAC 1-11 aircraft. The aims of the tests were, (i) to demonstrate real-time differential GNSS position-fixing, (ii) to establish the accuracy improvements brought about, and (iii) to examine the effects of data-link latency and satellite PDOP on the solution accuracy.

Degradation of metallic materials studied by correlative tomography

NASA Astrophysics Data System (ADS)

Burnett, T. L.; Holroyd, N. J. H.; Lewandowski, J. J.; Ogurreck, M.; Rau, C.; Kelley, R.; Pickering, E. J.; Daly, M.; Sherry, A. H.; Pawar, S.; Slater, T. J. A.; Withers, P. J.

2017-07-01

There are a huge array of characterization techniques available today and increasingly powerful computing resources allowing for the effective analysis and modelling of large datasets. However, each experimental and modelling tool only spans limited time and length scales. Correlative tomography can be thought of as the extension of correlative microscopy into three dimensions connecting different techniques, each providing different types of information, or covering different time or length scales. Here the focus is on the linking of time lapse X-ray computed tomography (CT) and serial section electron tomography using the focussed ion beam (FIB)-scanning electron microscope to study the degradation of metals. Correlative tomography can provide new levels of detail by delivering a multiscale 3D picture of key regions of interest. Specifically, the Xe+ Plasma FIB is used as an enabling tool for large-volume high-resolution serial sectioning of materials, and also as a tool for preparation of microscale test samples and samples for nanoscale X-ray CT imaging. The exemplars presented illustrate general aspects relating to correlative workflows, as well as to the time-lapse characterisation of metal microstructures during various failure mechanisms, including ductile fracture of steel and the corrosion of aluminium and magnesium alloys. Correlative tomography is already providing significant insights into materials behaviour, linking together information from different instruments across different scales. Multiscale and multifaceted work flows will become increasingly routine, providing a feed into multiscale materials models as well as illuminating other areas, particularly where hierarchical structures are of interest.

Gaining control: changing relations between executive control and processing speed and their relevance for mathematics achievement over course of the preschool period

PubMed Central

Clark, Caron A. C.; Nelson, Jennifer Mize; Garza, John; Sheffield, Tiffany D.; Wiebe, Sandra A.; Espy, Kimberly Andrews

2014-01-01

Early executive control (EC) predicts a range of academic outcomes and shows particularly strong associations with children's mathematics achievement. Nonetheless, a major challenge for EC research lies in distinguishing EC from related cognitive constructs that also are linked to achievement outcomes. Developmental cascade models suggest that children's information processing speed is a driving mechanism in cognitive development that supports gains in working memory, inhibitory control and associated cognitive abilities. Accordingly, individual differences in early executive task performance and their relation to mathematics may reflect, at least in part, underlying variation in children's processing speed. The aims of this study were to: (1) examine the degree of overlap between EC and processing speed at different preschool age points; and (2) determine whether EC uniquely predicts children's mathematics achievement after accounting for individual differences in processing speed. As part of a longitudinal, cohort-sequential study, 388 children (50% boys; 44% from low income households) completed the same battery of EC tasks at ages 3, 3.75, 4.5, and 5.25 years. Several of the tasks incorporated baseline speeded naming conditions with minimal EC demands. Multidimensional latent models were used to isolate the variance in executive task performance that did not overlap with baseline processing speed, covarying for child language proficiency. Models for separate age points showed that, while EC did not form a coherent latent factor independent of processing speed at age 3 years, it did emerge as a distinct factor by age 5.25. Although EC at age 3 showed no distinct relation with mathematics achievement independent of processing speed, EC at ages 3.75, 4.5, and 5.25 showed independent, prospective links with mathematics achievement. Findings suggest that EC and processing speed are tightly intertwined in early childhood. As EC becomes progressively decoupled from processing speed with age, it begins to take on unique, discriminative importance for children's mathematics achievement. PMID:24596563

Pilot Neil Armstrong with X-15 #1

NASA Technical Reports Server (NTRS)

1960-01-01

Dryden pilot Neil Armstrong is seen here next to the X-15 ship #1 (56-6670) after a research flight. Armstrong made his first X-15 flight on November 30, 1960, in the #1 X-15. He made his second flight on December 9, 1960, in the same aircraft. This was the first X-15 flight to use the ball nose, which provided accurate measurement of air speed and flow angle at supersonic and hypersonic speeds. The servo-actuated ball nose can be seen in this photo in front of Armstrong's right hand. The X-15 employed a non-standard landing gear. It had a nose gear with a wheel and tire, but the main landing consisted of skids mounted at the rear of the vehicle. In the photo, the left skid is visible, as are marks on the lakebed from both skids. Because of the skids, the rocket-powered aircraft could only land on a dry lakebed, not on a concrete runway. The X-15 was a rocket-powered aircraft. The original three aircraft were about 50 ft long with a wingspan of 22 ft. The modified #2 aircraft (X-15A-2 was longer.) They were a missile-shaped vehicles with unusual wedge-shaped vertical tails, thin stubby wings, and unique side fairings that extended along the side of the fuselage. The X-15 weighed about 14,000 lb empty and approximately 34,000 lb at launch. The XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., was pilot controlled and was rated at 57,000 lb of thrust, although there are indications that it actually achieved up to 60,000 lb. North American Aviation built three X-15 aircraft for the program. The X-15 research aircraft was developed to provide in-flight information and data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. A follow-on program used the aircraft as testbeds to carry various scientific experiments beyond the Earth's atmosphere on a repeated basis. For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls such as rudder surfaces on the vertical stabilizers to control yaw and movable horizontal stabilizers to control pitch when moving in synchronization or roll when moved differentially. For flight in the thin air outside of the appreciable Earth's atmosphere, the X-15 used a reaction control system. Hydrogen peroxide thrust rockets located on the nose of the aircraft provided pitch and yaw control. Those on the wings provided roll control. Because of the large fuel consumption, the X-15 was air launched from a B-52 aircraft at approximately 45,000 ft and a speed of about 500 mph. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing. Generally, one of two types of X-15 flight profiles was used; a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude. The X-15 was flown over a period of nearly 10 years -- June 1959 to Oct. 1968 -- and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of manned hypersonic flight. Information gained from the highly successful X-15 program contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and also the Space Shuttle program. The X-15s made a total of 199 flights, and were manufactured by North American Aviation. X-15-1, serial number 56-6670, is now located at the National Air and Space Museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio. X-15-3, serial number 56-6672, crashed on 15 November 1967, resulting in the death of Maj. Michael J. Adams.

20-meter underwater wireless optical communication link with 1.5 Gbps data rate.

PubMed

Shen, Chao; Guo, Yujian; Oubei, Hassan M; Ng, Tien Khee; Liu, Guangyu; Park, Ki-Hong; Ho, Kang-Ting; Alouini, Mohamed-Slim; Ooi, Boon S

2016-10-31

The video streaming, data transmission, and remote control in underwater call for high speed (Gbps) communication link with a long channel length (~10 meters). We present a compact and low power consumption underwater wireless optical communication (UWOC) system utilizing a 450-nm laser diode (LD) and a Si avalanche photodetector. With the LD operating at a driving current of 80 mA with an optical power of 51.3 mW, we demonstrated a high-speed UWOC link offering a data rate up to 2 Gbps over a 12-meter-long, and 1.5 Gbps over a record 20-meter-long underwater channel. The measured bit-error rate (BER) are 2.8 × 10^-5, and 3.0 × 10^-3, respectively, which pass well the forward error correction (FEC) criterion.

The selective use of functional optical variables in the control of forward speed

NASA Technical Reports Server (NTRS)

Johnson, Walter W.; Awe, Cynthia A.

1994-01-01

Previous work on the perception and control of simulated vehicle speed has examined the contributions of optical flow rate (angular visual speed) and texture, or edge rate (frequency of passing terrain objects or markings) on the perception and control of forward speed. However, these studies have not examined the ability to selectively use edge rate or flow rate. The two studies presented here show that this ability is far greater for pilots than non-pilots, as would be expected since pilots must control vehicular speed over a variety of altitudes where flow rates change independently of forward speed. These studies also show that this ability to selectively use these variables is linked to the visual contextual information about the relative validity (linkage with speed) of the two variables. Subjective judgment data also indicated that awareness of altitude and ground texture density did not mediate ground speed awareness.

Effective dynamics of a random walker on a heterogeneous ring: Exact results

NASA Astrophysics Data System (ADS)

Masharian, S. R.

2018-07-01

In this paper, by considering a biased random walker hopping on a one-dimensional lattice with a ring geometry, we investigate the fluctuations of the speed of the random walker. We assume that the lattice is heterogeneous i.e. the hopping rate of the random walker between the first and the last lattice sites is different from the hopping rate of the random walker between the other links of the lattice. Assuming that the average speed of the random walker in the steady-state is v∗, we have been able to find the unconditional effective dynamics of the random walker where the absolute value of the average speed of the random walker is -v∗. Using a perturbative method in the large system-size limit, we have also been able to show that the effective hopping rates of the random walker near the defective link are highly site-dependent.

Implementation of a MFAC based position sensorless drive for high speed BLDC motors with nonideal back EMF.

PubMed

Li, Haitao; Ning, Xin; Li, Wenzhuo

2017-03-01

In order to improve the reliability and reduce power consumption of the high speed BLDC motor system, this paper presents a model free adaptive control (MFAC) based position sensorless drive with only a dc-link current sensor. The initial commutation points are obtained by detecting the phase of EMF zero-crossing point and then delaying 30 electrical degrees. According to the commutation error caused by the low pass filter (LPF) and other factors, the relationship between commutation error angle and dc-link current is analyzed, a corresponding MFAC based control method is proposed, and the commutation error can be corrected by the controller in real time. Both the simulation and experimental results show that the proposed correction method can achieve ideal commutation effect within the entire operating speed range. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Design of a dataway processor for a parallel image signal processing system

NASA Astrophysics Data System (ADS)

Nomura, Mitsuru; Fujii, Tetsuro; Ono, Sadayasu

1995-04-01

Recently, demands for high-speed signal processing have been increasing especially in the field of image data compression, computer graphics, and medical imaging. To achieve sufficient power for real-time image processing, we have been developing parallel signal-processing systems. This paper describes a communication processor called 'dataway processor' designed for a new scalable parallel signal-processing system. The processor has six high-speed communication links (Dataways), a data-packet routing controller, a RISC CORE, and a DMA controller. Each communication link operates at 8-bit parallel in a full duplex mode at 50 MHz. Moreover, data routing, DMA, and CORE operations are processed in parallel. Therefore, sufficient throughput is available for high-speed digital video signals. The processor is designed in a top- down fashion using a CAD system called 'PARTHENON.' The hardware is fabricated using 0.5-micrometers CMOS technology, and its hardware is about 200 K gates.

Advances in measuring techniques for turbine cooling test rigs - Status report

NASA Technical Reports Server (NTRS)

Pollack, F. G.

1974-01-01

Instrumentation development pertaining to turbine cooling research has resulted in the design and testing of several new systems. Pressure measurements on rotating components are being made with a rotating system incorporating ten miniature transducers and a slip-ring assembly. The system has been tested successfully up to speeds of 9000 rpm. An advanced system development combining pressure transducer and thermocouple signals is also underway. Thermocouple measurements on rotating components are transferred off the shaft by a 72-channel rotating data system. Thermocouple data channels are electronically processed on board and then removed from the shaft in the form of a digital serial train by one winding of a rotary transformer.

F-15 HiDEC landing

NASA Technical Reports Server (NTRS)

1993-01-01

NASA's HIDEC (Highly Integrated Digital Electronic Control) F-15 aircraft nears the runway after a flight out of NASA's Dryden Flight Research Center, Edwards, California. The last project it was used for at Dryden was development of a computer-assisted engine control system that lets a plane land safely with only engine power if its normal control surfaces such as elevators, rudders or ailerons are disabled. The flight control system helps the pilot control the engines to turn the aircraft, climb, descend and eventually land safely by varying the speed of the engines one at a time or together. The HIDEC F-15A, built as the number eight prototype (Serial #71-0287), has now been retired.

The microscale evolution of the erosion front of blood clots exposed to ultrasound stimulated microbubbles.

PubMed

Acconcia, Christopher N; Leung, Ben Y C; Goertz, David E

2016-05-01

Serial two-photon microscopy of blood clots with fluorescently tagged fibrin networks was conducted during microbubble-mediated sonothrombolysis to examine the microscale evolution of the resulting erosion front. The development of a complex zonal erosion pattern was observed, comprised of a cell depleted layer of fibrin network overlying intact clot which then underwent progressive recession. The fibrin zone architecture was dependent on exposure conditions with 0.1 MPa causing no erosion, 0.39 MPa resulting in homogenous structure, and combination 0.39/0.96 MPa pulses forming large-scale tunnels. High speed imaging and Coulter counter data indicated the fibrin zone formation process involves the ejection of intact erythrocytes.

Accumulate-Repeat-Accumulate-Accumulate Codes

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

2007-01-01

Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

A plot twist: the continuing story of VCSELs at AOC

NASA Astrophysics Data System (ADS)

Guenter, James K.; Tatum, Jim A.; Hawthorne, Robert A., III; Johnson, Ralph H.; Mathes, David T.; Hawkins, Bobby M.

2005-03-01

During a year of substantial consolidation in the VCSEL industry, Honeywell sold their VCSEL Optical Products Division, which has now officially changed its name to Advanced Optical Components (AOC). Both manufacture and applied research continue, however. Some of the developments of the past year are discussed in this paper. They include advances in the understanding of VCSEL degradation physics, substantial improvements in long-wavelength VCSEL performance, and continuing progress in manufacturing technology. In addition, higher speed serial communications products, at 10 gigabits and particularly at 4 gigabits per second, have shown faster than predicted growth. We place these technologies and AOC's approach to them in a market perspective, along with other emerging applications.

Femtosecond X-ray diffraction from an aerosolized beam of protein nanocrystals

DOE PAGES

Awel, Salah; Kirian, Richard A.; Wiedorn, Max O.; ...

2018-02-01

High-resolution Bragg diffraction from aerosolized single granulovirus nanocrystals using an X-ray free-electron laser is demonstrated. The outer dimensions of the in-vacuum aerosol injector components are identical to conventional liquid-microjet nozzles used in serial diffraction experiments, which allows the injector to be utilized with standard mountings. As compared with liquid-jet injection, the X-ray scattering background is reduced by several orders of magnitude by the use of helium carrier gas rather than liquid. Such reduction is required for diffraction measurements of small macromolecular nanocrystals and single particles. High particle speeds are achieved, making the approach suitable for use at upcoming high-repetition-rate facilities.

Developmental Changes in the Visual Span for Reading

PubMed Central

Kwon, MiYoung; Legge, Gordon E.; Dubbels, Brock R.

2007-01-01

The visual span for reading refers to the range of letters, formatted as in text, that can be recognized reliably without moving the eyes. It is likely that the size of the visual span is determined primarily by characteristics of early visual processing. It has been hypothesized that the size of the visual span imposes a fundamental limit on reading speed (Legge, Mansfield, & Chung, 2001). The goal of the present study was to investigate developmental changes in the size of the visual span in school-age children, and the potential impact of these changes on children’s reading speed. The study design included groups of 10 children in 3rd, 5th, and 7th grade, and 10 adults. Visual span profiles were measured by asking participants to recognize letters in trigrams (random strings of three letters) flashed for 100 ms at varying letter positions left and right of the fixation point. Two print sizes (0.25° and 1.0°) were used. Over a block of trials, a profile was built up showing letter recognition accuracy (% correct) versus letter position. The area under this profile was defined to be the size of the visual span. Reading speed was measured in two ways: with Rapid Serial Visual Presentation (RSVP) and with short blocks of text (termed Flashcard presentation). Consistent with our prediction, we found that the size of the visual span increased linearly with grade level and it was significantly correlated with reading speed for both presentation methods. Regression analysis using the size of the visual span as a predictor indicated that 34% to 52% of variability in reading speeds can be accounted for by the size of the visual span. These findings are consistent with a significant role of early visual processing in the development of reading skills. PMID:17845810

Nano- to microscale dynamics of P-selectin detachment from leukocyte interfaces. II. Tether flow terminated by P-selectin dissociation from PSGL-1.

PubMed

Heinrich, Volkmar; Leung, Andrew; Evans, Evan

2005-03-01

We have used a biomembrane force probe decorated with P-selectin to form point attachments with PSGL-1 receptors on a human neutrophil (PMN) in a calcium-containing medium and then to quantify the forces experienced by the attachment during retraction of the PMN at fixed speed. From first touch to final detachment, the typical force history exhibited the following sequence of events: i), an initial linear-elastic displacement of the PMN surface, ii), an abrupt crossover to viscoplastic flow that signaled membrane separation from the interior cytoskeleton and the beginning of a membrane tether, and iii), the final detachment from the probe tip most often by one precipitous step of P-selectin:PSGL-1 dissociation. Analyzing the initial elastic response and membrane unbinding from the cytoskeleton in our companion article I, we focus in this article on the regime of tether extrusion that nearly always occurred before release of the extracellular adhesion bond at pulling speeds > or =1 microm/s. The force during tether growth appeared to approach a plateau at long times. Examined over a large range of pulling speeds up to 150 microm/s, the plateau force exhibited a significant shear thinning as indicated by a weak power-law dependence on pulling speed, f(infinity) = 60 pN(nu(pull)/microm/s)(0.25). Using this shear-thinning response to describe the viscous element in a nonlinear Maxwell-like fluid model, we show that a weak serial-elastic component with a stiffness of approximately 0.07 pN/nm provides good agreement with the time course of the tether force approach to the plateau under constant pulling speed.

SR-71 Ship #1 on Ramp

NASA Technical Reports Server (NTRS)

1994-01-01

This photo shows a head-on shot of NASA's SR-71A aircraft on the ramp at NASA's Dryden Flight Research Center, Edwards, California. NASA operated two SR-71s, an SR-71A and an SR- 71B pilot trainer aircraft, both based at Dryden, at that particular point in time. The SR-71 was designed and built by the Lockheed Skunk Works, now the Lockheed Martin Skunk Works. Studies have shown that less than 20 percent of the total thrust used to fly at Mach 3 is produced by the basic engine itself. The balance of the total thrust is produced by the unique design of the engine inlet and 'moveable spike' system at the front of the engine nacelles, and by the ejector nozzles at the exhaust which burn air compressed in the engine bypass system. Data from the SR-71 high speed research program will be used to aid designers of future supersonic/hypersonic aircraft and propulsion systems, including a high speed civil transport. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

Empirical study of the role of the topology in spreading on communication networks

NASA Astrophysics Data System (ADS)

Medvedev, Alexey; Kertesz, Janos

2017-03-01

Topological aspects, like community structure, and temporal activity patterns, like burstiness, have been shown to severely influence the speed of spreading in temporal networks. We study the influence of the topology on the susceptible-infected (SI) spreading on time stamped communication networks, as obtained from a dataset of mobile phone records. We consider city level networks with intra- and inter-city connections. The networks using only intra-city links are usually sparse, where the spreading depends mainly on the average degree. The inter-city links serve as bridges in spreading, speeding up considerably the process. We demonstrate the effect also on model simulations.

Dashboard Videos

NASA Astrophysics Data System (ADS)

Gleue, Alan D.; Depcik, Chris; Peltier, Ted

2012-11-01

Last school year, I had a web link emailed to me entitled "A Dashboard Physics Lesson." The link, created and posted by Dale Basier on his Lab Out Loud blog, illustrates video of a car's speedometer synchronized with video of the road. These two separate video streams are compiled into one video that students can watch and analyze. After seeing this website and video, I decided to create my own dashboard videos to show to my high school physics students. I have produced and synchronized 12 separate dashboard videos, each about 10 minutes in length, driving around the city of Lawrence, KS, and Douglas County, and posted them to a website.2 Each video reflects different types of driving: both positive and negative accelerations and constant speeds. As shown in Fig. 1, I was able to capture speed, distance, and miles per gallon from my dashboard instrumentation. By linking this with a stopwatch, each of these quantities can be graphed with respect to time. I anticipate and hope that teachers will find these useful in their own classrooms, i.e., having physics students watch the videos and create their own motion maps (distance-time, speed-time) for study.

Sensitivity and Specificity of Human Immunodeficiency Virus Rapid Serologic Assays and Testing Algorithms in an Antenatal Clinic in Abidjan, Ivory Coast

PubMed Central

Koblavi-Dème, Stéphania; Maurice, Chantal; Yavo, Daniel; Sibailly, Toussaint S.; N′guessan, Kabran; Kamelan-Tano, Yvonne; Wiktor, Stefan Z.; Roels, Thierry H.; Chorba, Terence; Nkengasong, John N.

2001-01-01

To evaluate serologic testing algorithms for human immunodeficiency virus (HIV) based on a combination of rapid assays among persons with HIV-1 (non-B subtypes) infection, HIV-2 infection, and HIV-1–HIV-2 dual infections in Abidjan, Ivory Coast, a total of 1,216 sera with known HIV serologic status were used to evaluate the sensitivity and specificity of four rapid assays: Determine HIV-1/2, Capillus HIV-1/HIV-2, HIV-SPOT, and Genie II HIV-1/HIV-2. Two serum panels obtained from patients recently infected with HIV-1 subtypes B and non-B were also included. Based on sensitivity and specificity, three of the four rapid assays were evaluated prospectively in parallel (serum samples tested by two simultaneous rapid assays) and serial (serum samples tested by two consecutive rapid assays) testing algorithms. All assays were 100% sensitive, and specificities ranged from 99.4 to 100%. In the prospective evaluation, both the parallel and serial algorithms were 100% sensitive and specific. Our results suggest that rapid assays have high sensitivity and specificity and, when used in parallel or serial testing algorithms, yield results similar to those of enzyme-linked immunosorbent assay-based testing strategies. HIV serodiagnosis based on rapid assays may be a valuable alternative in implementing HIV prevention and surveillance programs in areas where sophisticated laboratories are difficult to establish. PMID:11325995

Robustness of serial clustering of extra-tropical cyclones to the choice of tracking method

NASA Astrophysics Data System (ADS)

Pinto, Joaquim G.; Ulbrich, Sven; Karremann, Melanie K.; Stephenson, David B.; Economou, Theodoros; Shaffrey, Len C.

2016-04-01

Cyclone families are a frequent synoptic weather feature in the Euro-Atlantic area in winter. Given appropriate large-scale conditions, the occurrence of such series (clusters) of storms may lead to large socio-economic impacts and cumulative losses. Recent studies analyzing Reanalysis data using single cyclone tracking methods have shown that serial clustering of cyclones occurs on both flanks and downstream regions of the North Atlantic storm track. This study explores the sensitivity of serial clustering to the choice of tracking method. With this aim, the IMILAST cyclone track database based on ERA-interim data is analysed. Clustering is estimated by the dispersion (ratio of variance to mean) of winter (DJF) cyclones passages near each grid point over the Euro-Atlantic area. Results indicate that while the general pattern of clustering is identified for all methods, there are considerable differences in detail. This can primarily be attributed to the differences in the variance of cyclone counts between the methods, which range up to one order of magnitude. Nevertheless, clustering over the Eastern North Atlantic and Western Europe can be identified for all methods and can thus be generally considered as a robust feature. The statistical links between large-scale patterns like the NAO and clustering are obtained for all methods, though with different magnitudes. We conclude that the occurrence of cyclone clustering over the Eastern North Atlantic and Western Europe is largely independent from the choice of tracking method and hence from the definition of a cyclone.

[Children exposure to PM10 on the way to school: Regulatory impact of speed regulation under 30km/h].

PubMed

Prud'homme, J

2018-03-01

In Paris, air pollution is now a persistent environmental problem, especially linked to diesel cars in circulation. Exposure of children to air pollution during the journey from home to school, which takes place during peak hours of traffic, is poorly documented. The purpose of this work was to identify spaces less exposed to PM10 pollution. We identified spatial recurrences in the relative distribution of air pollution levels using PM10 geolocated measures taken along a fixed circuit, crossing, among others, a speed regulation zone (<30km/h). Measurements were made eight mornings between 8 and 9 a.m., in April and September 2016 in the 14th district of Paris. We obtained a hierarchical classification of spaces in terms of recurrence of relative levels of PM10 concentration. The cartography of the results revealed that the spaces more exposed to high concentrations were found similarly along main roads, side streets and speed regulation<30km/h) zones. These findings suggest speed regulation is insufficient to reduce individual exposure in city streets. Elements linked to the functional aspects of the street (commercial/residential) were apparently as important as traffic speed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The aero optics effect on near space laser communication optical system

NASA Astrophysics Data System (ADS)

Hu, Yuan; Fu, Yuegang; Jiang, Huilin

2013-08-01

With the developing of the space laser communication link, the performance index including higher transfer speed, extending transfer distance, and environmental adaptability, all ask the system accuracy and indexes improving. Special the developing near space platform, its environmental is extremes, the near space drone and other airplane flight speed is very quickly from the subsonic to supersonic. The aero optics effect caused by high speed will generate a thin turbulent air layer. It affects the performance of laser communication optical system by laser light vibration, deviation and so on, further more affects the performance of laser communication system working performance, even can't communication. Therefore, for achieving optical system indexes, we need do more research in optical system near space aero optics environmental adaptability. In this paper, near space link environmental characteristic are researched. And on the base of the aero optics theory, computer simulating method is applied to analyze the relationship among the altitude, the flight speed and the image dispersion. The result shows that, the aero optics effect cannot be ignored when the terminal is in low altitude or is moving with supersonic speed. The effect must be taken into considered from overall design. The result will provide the basis of research design.

An interdisciplinary school project using a Nintendo Wii controller for measuring car speed

NASA Astrophysics Data System (ADS)

Hansen, Nils Kristian; Mitchell, James Robert

2013-03-01

This work examines the feasibility of employing a Nintendo Wii game controller for measuring car speed in an interdisciplinary school project. It discusses the physical characteristics of the controller and of vehicle headlights. It suggests how an experiment may be linked to topics in mathematics, statistics, physics and computer science. An algorithm for calculating speed from repeated recordings of car headlights is provided. Finally the results of repeated experiments with an approaching car are provided.

The eyeball killer: serial killings with postmortem globe enucleation.

PubMed

Coyle, Julie; Ross, Karen F; Barnard, Jeffrey J; Peacock, Elizabeth; Linch, Charles A; Prahlow, Joseph A

2015-05-01

Although serial killings are relatively rare, they can be the cause of a great deal of anxiety while the killer remains at-large. Despite the fact that the motivations for serial killings are typically quite complex, the psychological analysis of a serial killer can provide valuable insight into how and why certain individuals become serial killers. Such knowledge may be instrumental in preventing future serial killings or in solving ongoing cases. In certain serial killings, the various incidents have a variety of similar features. Identification of similarities between separate homicidal incidents is necessary to recognize that a serial killer may be actively killing. In this report, the authors present a group of serial killings involving three prostitutes who were shot to death over a 3-month period. Scene and autopsy findings, including the unusual finding of postmortem enucleation of the eyes, led investigators to recognize the serial nature of the homicides. © 2015 American Academy of Forensic Sciences.

Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy

PubMed Central

Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

2016-01-01

Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in children with cerebral palsy. The current results thereby partly support the suggestion that facilitating arm swing in specific situations possibly enhances safety and reduces the risk of falling in children with cerebral palsy. PMID:27471457

Kinematic functions for the 7 DOF robotics research arm

NASA Technical Reports Server (NTRS)

Kreutz, K.; Long, M.; Seraji, Homayoun

1989-01-01

The Robotics Research Model K-1207 manipulator is a redundant 7R serial link arm with offsets at all joints. To uniquely determine joint angles for a given end-effector configuration, the redundancy is parameterized by a scalar variable which corresponds to the angle between the manipulator elbow plane and the vertical plane. The forward kinematic mappings from joint-space to end-effector configuration and elbow angle, and the augmented Jacobian matrix which gives end-effector and elbow angle rates as a function of joint rates, are also derived.

A USB 2.0 computer interface for the UCO/Lick CCD cameras

NASA Astrophysics Data System (ADS)

Wei, Mingzhi; Stover, Richard J.

2004-09-01

The new UCO/Lick Observatory CCD camera uses a 200 MHz fiber optic cable to transmit image data and an RS232 serial line for low speed bidirectional command and control. Increasingly RS232 is a legacy interface supported on fewer computers. The fiber optic cable requires either a custom interface board that is plugged into the mainboard of the image acquisition computer to accept the fiber directly or an interface converter that translates the fiber data onto a widely used standard interface. We present here a simple USB 2.0 interface for the UCO/Lick camera. A single USB cable connects to the image acquisition computer and the camera's RS232 serial and fiber optic cables plug into the USB interface. Since most computers now support USB 2.0 the Lick interface makes it possible to use the camera on essentially any modern computer that has the supporting software. No hardware modifications or additions to the computer are needed. The necessary device driver software has been written for the Linux operating system which is now widely used at Lick Observatory. The complete data acquisition software for the Lick CCD camera is running on a variety of PC style computers as well as an HP laptop.

Optimizations of a Hardware Decoder for Deep-Space Optical Communications

NASA Technical Reports Server (NTRS)

Cheng, Michael K.; Nakashima, Michael A.; Moision, Bruce E.; Hamkins, Jon

2007-01-01

The National Aeronautics and Space Administration has developed a capacity approaching modulation and coding scheme that comprises a serial concatenation of an inner accumulate pulse-position modulation (PPM) and an outer convolutional code [or serially concatenated PPM (SCPPM)] for deep-space optical communications. Decoding of this code uses the turbo principle. However, due to the nonbinary property of SCPPM, a straightforward application of classical turbo decoding is very inefficient. Here, we present various optimizations applicable in hardware implementation of the SCPPM decoder. More specifically, we feature a Super Gamma computation to efficiently handle parallel trellis edges, a pipeline-friendly 'maxstar top-2' circuit that reduces the max-only approximation penalty, a low-latency cyclic redundancy check circuit for window-based decoders, and a high-speed algorithmic polynomial interleaver that leads to memory savings. Using the featured optimizations, we implement a 6.72 megabits-per-second (Mbps) SCPPM decoder on a single field-programmable gate array (FPGA). Compared to the current data rate of 256 kilobits per second from Mars, the SCPPM coded scheme represents a throughput increase of more than twenty-six fold. Extension to a 50-Mbps decoder on a board with multiple FPGAs follows naturally. We show through hardware simulations that the SCPPM coded system can operate within 1 dB of the Shannon capacity at nominal operating conditions.

Crash avoidance in response to challenging driving events: The roles of age, serialization, and driving simulator platform.

PubMed

Bélanger, Alexandre; Gagnon, Sylvain; Stinchcombe, Arne

2015-09-01

We examined the crash avoidance behaviors of older and middle-aged drivers in reaction to six simulated challenging road events using two different driving simulator platforms. Thirty-five healthy adults aged 21-36 years old (M=28.9±3.96) and 35 healthy adults aged 65-83 years old (M=72.1±4.34) were tested using a mid-level simulator, and 27 adults aged 21-38 years old (M=28.6±6.63) and 27 healthy adults aged 65-83 years old (M=72.7±5.39) were tested on a low-cost desktop simulator. Participants completed a set of six challenging events varying in terms of the maneuvers required, avoiding space given, directional avoidance cues, and time pressure. Results indicated that older drivers showed higher crash risk when events required multiple synchronized reactions. In situations that required simultaneous use of steering and braking, older adults tended to crash significantly more frequently. As for middle-aged drivers, their crashes were attributable to faster driving speed. The same age-related driving patterns were observed across simulator platforms. Our findings support the hypothesis that older adults tend to react serially while engaging in cognitively challenging road maneuvers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radiation-hard mid-power booster optical fiber amplifiers for high-speed digital and analogue satellite laser communication links

NASA Astrophysics Data System (ADS)

Stampoulidis, L.; Kehayas, E.; Stevens, G.; Henwood-Moroney, L.; Hosking, P.; Robertson, A.

2017-11-01

Optical laser communications (OLC) has been identified as the technology to enable high-data rate, secure links between and within satellites, as well as between satellites and ground stations with decreased mass, size, and electrical power compared to traditional RF technology.

Quantitative computed tomography determined regional lung mechanics in normal nonsmokers, normal smokers and metastatic sarcoma subjects.

PubMed

Choi, Jiwoong; Hoffman, Eric A; Lin, Ching-Long; Milhem, Mohammed M; Tessier, Jean; Newell, John D

2017-01-01

Extra-thoracic tumors send out pilot cells that attach to the pulmonary endothelium. We hypothesized that this could alter regional lung mechanics (tissue stiffening or accumulation of fluid and inflammatory cells) through interactions with host cells. We explored this with serial inspiratory computed tomography (CT) and image matching to assess regional changes in lung expansion. We retrospectively assessed 44 pairs of two serial CT scans on 21 sarcoma patients: 12 without lung metastases and 9 with lung metastases. For each subject, two or more serial inspiratory clinically-derived CT scans were retrospectively collected. Two research-derived control groups were included: 7 normal nonsmokers and 12 asymptomatic smokers with two inspiratory scans taken the same day or one year apart respectively. We performed image registration for local-to-local matching scans to baseline, and derived local expansion and density changes at an acinar scale. Welch two sample t test was used for comparison between groups. Statistical significance was determined with a p value < 0.05. Lung regions of metastatic sarcoma patients (but not the normal control group) demonstrated an increased proportion of normalized lung expansion between the first and second CT. These hyper-expanded regions were associated with, but not limited to, visible metastatic lung lesions. Compared with the normal control group, the percent of increased normalized hyper-expanded lung in sarcoma subjects was significantly increased (p < 0.05). There was also evidence of increased lung "tissue" volume (non-air components) in the hyper-expanded regions of the cancer subjects relative to non-hyper-expanded regions. "Tissue" volume increase was present in the hyper-expanded regions of metastatic and non-metastatic sarcoma subjects. This putatively could represent regional inflammation related to the presence of tumor pilot cell-host related interactions. This new quantitative CT (QCT) method for linking serial acquired inspiratory CT images may provide a diagnostic and prognostic means to objectively characterize regional responses in the lung following oncological treatment and monitoring for lung metastases.

Understanding repeated non-attendance in health services: a pilot analysis of administrative data and full study protocol for a national retrospective cohort.

PubMed

Williamson, Andrea E; Ellis, David A; Wilson, Philip; McQueenie, Ross; McConnachie, Alex

2017-02-14

Understanding the causes of low engagement in healthcare is a pre-requisite for improving health services' contribution to tackling health inequalities. Low engagement includes missing healthcare appointments. Serially (having a pattern of) missing general practice (GP) appointments may provide a risk marker for vulnerability and poorer health outcomes. A proof of concept pilot using GP appointment data and a focus group with GPs informed the development of missed appointment categories: patients can be classified based on the number of appointments missed each year. The full study, using a retrospective cohort design, will link routine health service and education data to determine the relationship between GP appointment attendance, health outcomes, healthcare usage, preventive health activity and social circumstances taking a life course approach and using data from the whole journey in the National Health Service (NHS) healthcare. 172 practices will be recruited (∼900 000 patients) across Scotland. The statistical analysis will focus on 2 key areas: factors that predict patients who serially miss appointments, and serial missed appointments as a predictor of future patient outcomes. Regression models will help understand how missed appointment patterns are associated with patient and practice characteristics. We shall identify key factors associated with serial missed appointments and potential interactions that might predict them. The results of the project will inform debates concerning how best to reduce non-attendance and increase patient engagement within healthcare systems. Significant non-academic beneficiaries include governments, policymakers and medical practitioners. Results will be disseminated via a combination of academic outputs (papers, conferences), social media and through collaborative public health/policy fora. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Anxiety state affects information processing speed in patients with multiple sclerosis.

PubMed

Goretti, Benedetta; Viterbo, R G; Portaccio, E; Niccolai, C; Hakiki, B; Piscolla, E; Iaffaldano, P; Trojano, M; Amato, M P

2014-04-01

The aim of this study was to investigate the impact of anxiety on the cognitive performance of a clinical sample of relapsing-remitting (RR) MS patients. One hundred ninety patients (140 females) were included in the study and assessed through the beck depression inventory, the state-trait anxiety inventory and the Rao's brief repeatable battery which assesses cognitive domains most frequently impaired in MS. As for neuropsychological performance, a total of 76 (40%) subjects fulfilled our criterion for cognitive impairment. Tests most frequently failed by cognitive impairment (CI) patients were those assessing complex attention and information processing speed [Simbol Digit Modalities Test (SDMT), Paced Auditory Serial Auditory Test (PASAT) 3 and 2] and verbal memory. In the univariate analysis, state anxiety was related to failure on the SDMT (p = 0.042), and marginally, to failure on the PASAT-3 (p = 0.068), and to the presence of CI (p = 0.082). Moderate/severe depression was detected in 38 (20%) patients and fatigue in 109 (57%). Higher depression scores were related to impairment on the ST (OR = 1.05; 95% CI 1.01-1.10; p = 0.029).

Families of FPGA-Based Accelerators for Approximate String Matching1

PubMed Central

Van Court, Tom; Herbordt, Martin C.

2011-01-01

Dynamic programming for approximate string matching is a large family of different algorithms, which vary significantly in purpose, complexity, and hardware utilization. Many implementations have reported impressive speed-ups, but have typically been point solutions – highly specialized and addressing only one or a few of the many possible options. The problem to be solved is creating a hardware description that implements a broad range of behavioral options without losing efficiency due to feature bloat. We report a set of three component types that address different parts of the approximate string matching problem. This allows each application to choose the feature set required, then make maximum use of the FPGA fabric according to that application’s specific resource requirements. Multiple, interchangeable implementations are available for each component type. We show that these methods allow the efficient generation of a large, if not complete, family of accelerators for this application. This flexibility was obtained while retaining high performance: We have evaluated a sample against serial reference codes and found speed-ups of from 150× to 400× over a high-end PC. PMID:21603598

A spectral analysis of the domain decomposed Monte Carlo method for linear systems

DOE PAGES

Slattery, Stuart R.; Evans, Thomas M.; Wilson, Paul P. H.

2015-09-08

The domain decomposed behavior of the adjoint Neumann-Ulam Monte Carlo method for solving linear systems is analyzed using the spectral properties of the linear oper- ator. Relationships for the average length of the adjoint random walks, a measure of convergence speed and serial performance, are made with respect to the eigenvalues of the linear operator. In addition, relationships for the effective optical thickness of a domain in the decomposition are presented based on the spectral analysis and diffusion theory. Using the effective optical thickness, the Wigner rational approxi- mation and the mean chord approximation are applied to estimate the leakagemore » frac- tion of random walks from a domain in the decomposition as a measure of parallel performance and potential communication costs. The one-speed, two-dimensional neutron diffusion equation is used as a model problem in numerical experiments to test the models for symmetric operators with spectral qualities similar to light water reactor problems. We find, in general, the derived approximations show good agreement with random walk lengths and leakage fractions computed by the numerical experiments.« less

Does Vertical Reading Help People with Macular Degeneration: An Exploratory Study

PubMed Central

Calabrèse, Aurélie; Liu, Tingting; Legge, Gordon E.

2017-01-01

Individuals with macular degeneration often develop a Preferred Retinal Locus (PRL) used in place of the impaired fovea. It is known that many people adopt a PRL left of the scotoma, which is likely to affect reading by occluding text to the right of fixation. For such individuals, we examined the possibility that reading vertical text, in which words are rotated 90° with respect to the normal horizontal orientation, would be beneficial for reading. Vertically oriented words would be tangential to the scotoma instead of being partially occluded by it. Here we report the results of an exploratory study that aimed at investigating this hypothesis. We trained individuals with macular degeneration who had PRLs left of their scotoma to read text rotated 90° clockwise and presented using rapid serial visual presentation (RSVP). Although training resulted in improved reading of vertical text, the training did not result in reading speeds that appreciably exceeded reading speeds following training with horizontal text. These results do not support the hypothesis that people with left PRLs read faster with vertical text. PMID:28114373

The fiber-optic high-speed data bus for a new generation of military aircraft

NASA Astrophysics Data System (ADS)

Uhlhorn, Roger W.

1991-02-01

The avionic suite for the next generation of military aircraft is being designed with component and module commonality in mind in order to control recurring costs and capitalize on economy of scale. The backbone of the suite fashioned out of these modular building blocks is the fiber-optic bit-serial time-division multiplexed high-speed data bus (HSDB), operating at 50 Mb/s, which provides command and control communications among most of the aircraft subsystems and can be used to provide communications for a fly-by-light flight-control system or for the block transfer of data between mass memories and data processors. The fiber-optic HSDB is examined from the top down, beginning with an overview of the evolution of avionic architectures. A review is given of the standardization activity associated with development of the network, the protocols chosen to implement the desired communication functions, configuration options, and the fiber-optic components used in the bus interfaces or other active nodes of the network. It is believed that the utility of the bus extends beyond aircraft to spacecraft, ships, and land vehicles.

A 181 GOPS AKAZE Accelerator Employing Discrete-Time Cellular Neural Networks for Real-Time Feature Extraction.

PubMed

Jiang, Guangli; Liu, Leibo; Zhu, Wenping; Yin, Shouyi; Wei, Shaojun

2015-09-04

This paper proposes a real-time feature extraction VLSI architecture for high-resolution images based on the accelerated KAZE algorithm. Firstly, a new system architecture is proposed. It increases the system throughput, provides flexibility in image resolution, and offers trade-offs between speed and scaling robustness. The architecture consists of a two-dimensional pipeline array that fully utilizes computational similarities in octaves. Secondly, a substructure (block-serial discrete-time cellular neural network) that can realize a nonlinear filter is proposed. This structure decreases the memory demand through the removal of data dependency. Thirdly, a hardware-friendly descriptor is introduced in order to overcome the hardware design bottleneck through the polar sample pattern; a simplified method to realize rotation invariance is also presented. Finally, the proposed architecture is designed in TSMC 65 nm CMOS technology. The experimental results show a performance of 127 fps in full HD resolution at 200 MHz frequency. The peak performance reaches 181 GOPS and the throughput is double the speed of other state-of-the-art architectures.

A high-speed linear algebra library with automatic parallelism

NASA Technical Reports Server (NTRS)

Boucher, Michael L.

1994-01-01

Parallel or distributed processing is key to getting highest performance workstations. However, designing and implementing efficient parallel algorithms is difficult and error-prone. It is even more difficult to write code that is both portable to and efficient on many different computers. Finally, it is harder still to satisfy the above requirements and include the reliability and ease of use required of commercial software intended for use in a production environment. As a result, the application of parallel processing technology to commercial software has been extremely small even though there are numerous computationally demanding programs that would significantly benefit from application of parallel processing. This paper describes DSSLIB, which is a library of subroutines that perform many of the time-consuming computations in engineering and scientific software. DSSLIB combines the high efficiency and speed of parallel computation with a serial programming model that eliminates many undesirable side-effects of typical parallel code. The result is a simple way to incorporate the power of parallel processing into commercial software without compromising maintainability, reliability, or ease of use. This gives significant advantages over less powerful non-parallel entries in the market.

Online measurement for geometrical parameters of wheel set based on structure light and CUDA parallel processing

NASA Astrophysics Data System (ADS)

Wu, Kaihua; Shao, Zhencheng; Chen, Nian; Wang, Wenjie

2018-01-01

The wearing degree of the wheel set tread is one of the main factors that influence the safety and stability of running train. Geometrical parameters mainly include flange thickness and flange height. Line structure laser light was projected on the wheel tread surface. The geometrical parameters can be deduced from the profile image. An online image acquisition system was designed based on asynchronous reset of CCD and CUDA parallel processing unit. The image acquisition was fulfilled by hardware interrupt mode. A high efficiency parallel segmentation algorithm based on CUDA was proposed. The algorithm firstly divides the image into smaller squares, and extracts the squares of the target by fusion of k_means and STING clustering image segmentation algorithm. Segmentation time is less than 0.97ms. A considerable acceleration ratio compared with the CPU serial calculation was obtained, which greatly improved the real-time image processing capacity. When wheel set was running in a limited speed, the system placed alone railway line can measure the geometrical parameters automatically. The maximum measuring speed is 120km/h.

Imaging system design and image interpolation based on CMOS image sensor

NASA Astrophysics Data System (ADS)

Li, Yu-feng; Liang, Fei; Guo, Rui

2009-11-01

An image acquisition system is introduced, which consists of a color CMOS image sensor (OV9620), SRAM (CY62148), CPLD (EPM7128AE) and DSP (TMS320VC5509A). The CPLD implements the logic and timing control to the system. SRAM stores the image data, and DSP controls the image acquisition system through the SCCB (Omni Vision Serial Camera Control Bus). The timing sequence of the CMOS image sensor OV9620 is analyzed. The imaging part and the high speed image data memory unit are designed. The hardware and software design of the image acquisition and processing system is given. CMOS digital cameras use color filter arrays to sample different spectral components, such as red, green, and blue. At the location of each pixel only one color sample is taken, and the other colors must be interpolated from neighboring samples. We use the edge-oriented adaptive interpolation algorithm for the edge pixels and bilinear interpolation algorithm for the non-edge pixels to improve the visual quality of the interpolated images. This method can get high processing speed, decrease the computational complexity, and effectively preserve the image edges.

Trajectory Tracking of a Planer Parallel Manipulator by Using Computed Force Control Method

NASA Astrophysics Data System (ADS)

Bayram, Atilla

2017-03-01

Despite small workspace, parallel manipulators have some advantages over their serial counterparts in terms of higher speed, acceleration, rigidity, accuracy, manufacturing cost and payload. Accordingly, this type of manipulators can be used in many applications such as in high-speed machine tools, tuning machine for feeding, sensitive cutting, assembly and packaging. This paper presents a special type of planar parallel manipulator with three degrees of freedom. It is constructed as a variable geometry truss generally known planar Stewart platform. The reachable and orientation workspaces are obtained for this manipulator. The inverse kinematic analysis is solved for the trajectory tracking according to the redundancy and joint limit avoidance. Then, the dynamics model of the manipulator is established by using Virtual Work method. The simulations are performed to follow the given planar trajectories by using the dynamic equations of the variable geometry truss manipulator and computed force control method. In computed force control method, the feedback gain matrices for PD control are tuned with fixed matrices by trail end error and variable ones by means of optimization with genetic algorithm.

Teleoperation of an experimental mobile vehicle via a free-space optical laser line-of-sight communication link for use in nuclear power plant environments

NASA Astrophysics Data System (ADS)

Girach, Khalid; Bouazza-Marouf, K.; Kerr, David; Hewit, Jim

1994-11-01

The paper describes the investigations carried out to implement a line of sight control and communication link for a mobile robot vehicle for use in structured nuclear semi-hazardous environments. Line of sight free space optical laser communication links for remote teleoperation have important applications in hazardous environments. They have certain advantages over radio/microwave links and umbilical control such as greater protection against generation of and susceptance to electro-magnetic fields. The cable-less environment provides increased integrity and mechanical freedom to the mobile robot. However, to maintain the communication link, continuous point and tracking is required between the base station and the mobile vehicle. This paper presents a novel two ended optical tracking system utilizing the communication laser beams and photodetectors. The mobile robot is a six wheel drive vehicle with a manipulator arm which can operate in a variety of terrain. The operator obtains visual feedback information from cameras placed on the vehicle. From this information, the speed and direction of the vehicle can be controlled from a joystick panel. We describe the investigations carried out for the communication of analogue video and digital data signals over the laser link for speed and direction control.

SR-71A - in Flight from Below at Takeoff

NASA Technical Reports Server (NTRS)

1997-01-01

With landing gear retracting, NASA Dryden Flight Research Center's SR-71A Blackbird, tail number 844, powers its way off the Edwards AFB runway with two Pratt & Whitney JT11D-20 engines rated at 34,000 pounds of thrust each, on a 1997 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

Edward (Ed) T. Schneider in Front of SR-71 Blackbird

NASA Technical Reports Server (NTRS)

1995-01-01

SR-71 research pilot Ed Schneider is pictured here in front of an SR-71 Blackbird on the ramp at the Dryden Flight Research Center, Edwards, California. Schneider became a NASA research pilot at Dryden in 1983. Data from the SR-71 program will be used to aid designers of future supersonic aircraft and propulsion systems. He retired as a NASA research pilot in September 2000. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Ship #1 on Ramp

NASA Technical Reports Server (NTRS)

1994-01-01

This look-down view of NASA's SR-71A aircraft shows the Blackbird on the ramp at the Dryden Flight Research Center, Edwards, California, with Rogers Dry Lake in the background. NASA operated two SR-71s, an SR-71A and an SR- 71B pilot trainer aircraft at that point in time, both based at Dryden. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Research Engineer Marta Bohn-Meyer

NASA Technical Reports Server (NTRS)

1992-01-01

This 1992 photo shows SR-71 flight engineer Marta Bohn-Meyer in front of one of NASA's SR-71 aircraft on the ramp at the Ames-Dryden Flight Research Facility (later, Dryden Flight Research Center), Edwards, California. An aerospace engineer who has been at Dryden since 1979, Bohn-Meyer is the first female crew member ever assigned to fly in the SR-71. Data from the SR-71 program carried out by NASA will be used to aid designers of future supersonic aircraft and propulsion systems. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Pilots and Crew (Smith, Meyer, Bohn-Meyer, Ishmael)

NASA Technical Reports Server (NTRS)

1991-01-01

The two pilot-engineer teams that flew the SR-71 aircraft at the NASA Ames-Dryden Flight Research Facility (later, Dryden Flight Research Center, Edwards, California, are, from left, pilot Rogers Smith, flight engineers Robert Meyer and Marta Bohn-Meyer, and pilot Steven Ishmael. The Meyers are the first husband-wife team of aeronautical engineers at Dryden on flight status. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71 Pilots and Crew (Smith, Meyer, Bohn-Meyer, Ishmael)

NASA Technical Reports Server (NTRS)

1991-01-01

The two pilot-engineer teams that flew the SR-71 aircraft at the NASA Ames-Dryden Flight Research Facility (later, Dryden Flight Research Center), Edwards, California, are, from top of ladder, pilot Rogers Smith, flight engineer Robert Meyer, pilot Steven Ishmael, and flight engineer Marta Bohn-Meyer. The Meyers are the first husband-wife team of aeronautical engineers at Dryden on flight status. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71B - in Flight with F-18 Chase Aircraft - View from Air Force Tanker

NASA Technical Reports Server (NTRS)

1996-01-01

NASA 831, an SR-71B operated by the Dryden Flight Research Center, Edwards, California, cruises over the Mojave Desert with an F/A-18 Hornet flying safety chase. They were photographed on a 1996 mission from an Air Force refueling tanker The F/A-18 Hornet is used primarily as a safety chase and support aircraft at Dryden. As support aircraft, the F-18s are used for safety chase, pilot proficiency and aerial photography. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

SR-71A Taking Off with Test Fixture Mounted Atop the Aft Section of the Aircraft and F-18 Chase Airc

NASA Technical Reports Server (NTRS)

1999-01-01

This photo shows a NASA's SR-71A Blackbird, followed by a NASA F/A-18 chase plane, taking off from the runway at the Dryden Flight Research Center, Edwards, California, on a 1999 flight. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

A Monte Carlo method using octree structure in photon and electron transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogawa, K.; Maeda, S.

Most of the early Monte Carlo calculations in medical physics were used to calculate absorbed dose distributions, and detector responses and efficiencies. Recently, data acquisition in Single Photon Emission CT (SPECT) has been simulated by a Monte Carlo method to evaluate scatter photons generated in a human body and a collimator. Monte Carlo simulations in SPECT data acquisition are generally based on the transport of photons only because the photons being simulated are low energy, and therefore the bremsstrahlung productions by the electrons generated are negligible. Since the transport calculation of photons without electrons is much simpler than that withmore » electrons, it is possible to accomplish the high-speed simulation in a simple object with one medium. Here, object description is important in performing the photon and/or electron transport using a Monte Carlo method efficiently. The authors propose a new description method using an octree representation of an object. Thus even if the boundaries of each medium are represented accurately, high-speed calculation of photon transport can be accomplished because the number of voxels is much fewer than that of the voxel-based approach which represents an object by a union of the voxels of the same size. This Monte Carlo code using the octree representation of an object first establishes the simulation geometry by reading octree string, which is produced by forming an octree structure from a set of serial sections for the object before the simulation; then it transports photons in the geometry. Using the code, if the user just prepares a set of serial sections for the object in which he or she wants to simulate photon trajectories, he or she can perform the simulation automatically using the suboptimal geometry simplified by the octree representation without forming the optimal geometry by handwriting.« less

Proteus: a reconfigurable computational network for computer vision

NASA Astrophysics Data System (ADS)

Haralick, Robert M.; Somani, Arun K.; Wittenbrink, Craig M.; Johnson, Robert; Cooper, Kenneth; Shapiro, Linda G.; Phillips, Ihsin T.; Hwang, Jenq N.; Cheung, William; Yao, Yung H.; Chen, Chung-Ho; Yang, Larry; Daugherty, Brian; Lorbeski, Bob; Loving, Kent; Miller, Tom; Parkins, Larye; Soos, Steven L.

1992-04-01

The Proteus architecture is a highly parallel MIMD, multiple instruction, multiple-data machine, optimized for large granularity tasks such as machine vision and image processing The system can achieve 20 Giga-flops (80 Giga-flops peak). It accepts data via multiple serial links at a rate of up to 640 megabytes/second. The system employs a hierarchical reconfigurable interconnection network with the highest level being a circuit switched Enhanced Hypercube serial interconnection network for internal data transfers. The system is designed to use 256 to 1,024 RISC processors. The processors use one megabyte external Read/Write Allocating Caches for reduced multiprocessor contention. The system detects, locates, and replaces faulty subsystems using redundant hardware to facilitate fault tolerance. The parallelism is directly controllable through an advanced software system for partitioning, scheduling, and development. System software includes a translator for the INSIGHT language, a parallel debugger, low and high level simulators, and a message passing system for all control needs. Image processing application software includes a variety of point operators neighborhood, operators, convolution, and the mathematical morphology operations of binary and gray scale dilation, erosion, opening, and closing.

Visuospatial bootstrapping: Binding useful visuospatial information during verbal working memory encoding does not require set-shifting executive resources.

PubMed

Calia, Clara; Darling, Stephen; Havelka, Jelena; Allen, Richard J

2018-05-01

Immediate serial recall of digits is better when the digits are shown by highlighting them in a familiar array, such as a phone keypad, compared with presenting them serially in a single location, a pattern referred to as "visuospatial bootstrapping." This pattern implies the establishment of temporary links between verbal and spatial working memory, alongside access to information in long-term memory. However, the role of working memory control processes like those implied by the "Central Executive" in bootstrapping has not been directly investigated. Here, we report a study addressing this issue, focusing on executive processes of attentional shifting. Tasks in which information has to be sequenced are thought to be heavily dependent on shifting. Memory for digits presented in keypads versus single locations was assessed under two secondary task load conditions, one with and one without a sequencing requirement, and hence differing in the degree to which they invoke shifting. Results provided clear evidence that multimodal binding (visuospatial bootstrapping) can operate independently of this form of executive control process.

A serial mediation model of message framing on intentions to receive the human papillomavirus (HPV) vaccine: revisiting the role of threat and efficacy perceptions.

PubMed

Krieger, Janice L; Sarge, Melanie A

2013-01-01

Previous research has yielded mixed findings regarding the potential for message framing to influence HPV vaccine-related intentions. Drawing on the Extended Parallel Process Model (EPPM), the current study focuses on the role of threat and efficacy as serial mediators linking message framing and HPV vaccine-related intentions. College-age females and their parents participated in a between-subjects, posttest only experiment to investigate whether behavioral intentions to talk to a doctor about the HPV vaccine differ as a function of framing messages in terms of disease prevention. For young women, framing messages as preventing genital warts (as compared to cancer prevention) significantly increased perceptions of self-efficacy, which enhanced response efficacy perceptions that, in turn, increased intentions to talk to a doctor about the HPV vaccine. There were no effects of message framing among parents. However, response efficacy was a significant mediator of self-efficacy and behavioral intentions for both the college-age females and their parents. The results of this study suggest new approaches for considering the relationship among EPPM constructs.

Effects of Aging on Arm Swing during Gait: The Role of Gait Speed and Dual Tasking.

PubMed

Mirelman, Anat; Bernad-Elazari, Hagar; Nobel, Tomer; Thaler, Avner; Peruzzi, Agnese; Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M

2015-01-01

Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30-77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3's (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30-40; 41-50; 51-60; 61-77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging.

Effects of Aging on Arm Swing during Gait: The Role of Gait Speed and Dual Tasking

PubMed Central

Mirelman, Anat; Bernad-Elazari, Hagar; Nobel, Tomer; Thaler, Avner; Peruzzi, Agnese; Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M.

2015-01-01

Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30–77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3’s (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30–40; 41–50; 51–60; 61–77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging. PMID:26305896

Combination Therapy of Intense Pulsed Light Therapy and Meibomian Gland Expression (IPL/MGX) Can Improve Dry Eye Symptoms and Meibomian Gland Function in Patients With Refractory Dry Eye: A Retrospective Analysis.

PubMed

Vegunta, Sravanthi; Patel, Dharmendra; Shen, Joanne F

2016-03-01

To assess the improvement in meibomian gland function and dry eye symptoms in patients with refractory dry eye treated with a combination therapy of intense pulsed light (IPL) and meibomian gland expression (MGX). Medical records of 81 consecutive patients with dry eye treated with serial IPL/MGX were retrospectively examined to determine the outcome. All patients had a minimum of 6 months of follow-up after the first IPL/MGX treatment. Patients typically received 1 to 4 IPL treatments spaced 4 to 6 weeks apart. Each IPL session included MGX. Thirty-five charts had complete data for inclusion in analysis. We reviewed demographics, ocular histories, Standard Patient Evaluation of Eye Dryness 2 (SPEED2) symptom survey scores, slit-lamp examinations, and meibomian gland evaluations (MGE) at baseline and at each visit before IPL/MGX treatments. The paired t test showed a significant (P < 0.0001) decrease in SPEED2 with IPL/MGX therapy. Of the 35 patients, 8 (23%) had a ≥50% decrease in SPEED2, 23 (66%) had a 1% to 49% decrease in SPEED2, 1 (3%) had no change in SPEED2, and 3 (9%) had an increase in SPEED2. The Paired t test showed a significant increase in MGE in the left eye but not in the right eye (OD P = 0.163 and OS P = 0.0002). Thirteen patients (37%) had improved MGE bilaterally. Eight patients (23%) had either a decrease in MGE bilaterally or a decrease in 1 eye with no change in the other eye. This retrospective analysis shows that the combination of IPL and MGX can significantly improve dry eye symptoms (in 89% of patients) and meibomian gland function (in 77% of patients in at least 1 eye).

71-Mbit/s ultraviolet-B LED communication link based on 8-QAM-OFDM modulation.

PubMed

Sun, Xiaobin; Zhang, Zhenyu; Chaaban, Anas; Ng, Tien Khee; Shen, Chao; Chen, Rui; Yan, Jianchang; Sun, Haiding; Li, Xiaohang; Wang, Junxi; Li, Jinmin; Alouini, Mohamed-Slim; Ooi, Boon S

2017-09-18

A demonstration of ultraviolet-B (UVB) communication link is implemented utilizing quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM). The demonstration is based on a 294-nm UVB-light-emitting-diode (UVB-LED) with a full-width at half-maximum (FWHM) of 9 nm and light output power of 190 μW, at 7 V, with a special silica gel lens on top of it. A -3-dB bandwidth of 29 MHz was measured and a high-speed near-solar-blind communication link with a data rate of 71 Mbit/s was achieved using 8-QAM-OFDM at perfect alignment. 23.6 Mbit/s using 2-QAM-OFDM when the angle subtended by the pointing directions of the UVB-LED and photodetector (PD) is 12 degrees, thus establishing a diffuse-line-of-sight (LOS) link. The measured bit-error rate (BER) of 2.8 ×10 -4 and 2.4 ×10 -4 , respectively, are well below the forward error correction (FEC) criterion of 3.8 ×10 -3 . The demonstrated high data-rate OFDM-based UVB communication link paves the way for realizing high-speed non-line-of-sight free-space optical communications.

High-performance parallel interface to synchronous optical network gateway

DOEpatents

St. John, Wallace B.; DuBois, David H.

1996-01-01

A system of sending and receiving gateways interconnects high speed data interfaces, e.g., HIPPI interfaces, through fiber optic links, e.g., a SONET network. An electronic stripe distributor distributes bytes of data from a first interface at the sending gateway onto parallel fiber optics of the fiber optic link to form transmitted data. An electronic stripe collector receives the transmitted data on the parallel fiber optics and reforms the data into a format effective for input to a second interface at the receiving gateway. Preferably, an error correcting syndrome is constructed at the sending gateway and sent with a data frame so that transmission errors can be detected and corrected in a real-time basis. Since the high speed data interface operates faster than any of the fiber optic links the transmission rate must be adapted to match the available number of fiber optic links so the sending and receiving gateways monitor the availability of fiber links and adjust the data throughput accordingly. In another aspect, the receiving gateway must have sufficient available buffer capacity to accept an incoming data frame. A credit-based flow control system provides for continuously updating the sending gateway on the available buffer capacity at the receiving gateway.

Fast thought speed induces risk taking.

PubMed

Chandler, Jesse J; Pronin, Emily

2012-04-01

In two experiments, we tested for a causal link between thought speed and risk taking. In Experiment 1, we manipulated thought speed by presenting neutral-content text at either a fast or a slow pace and having participants read the text aloud. In Experiment 2, we manipulated thought speed by presenting fast-, medium-, or slow-paced movie clips that contained similar content. Participants who were induced to think more quickly took more risks with actual money in Experiment 1 and reported greater intentions to engage in real-world risky behaviors, such as unprotected sex and illegal drug use, in Experiment 2. These experiments provide evidence that faster thinking induces greater risk taking.

QI2S - Quick Image Interpretation System

NASA Astrophysics Data System (ADS)

Naghmouchi, Jamin; Aviely, Peleg; Ginosar, Ran; Ober, Giovanna; Bischoff, Ole; Nadler, Ron; Guiser, David; Citroen, Meira; Freddi, Riccardo; Berekovic, Mladen

2015-09-01

The evolution of the Earth Observation mission will be driven by many factors, and the deveploment of new processing paradigms to facilitate data downlink, handling and storage will be a key factor. Next generation EO satellites will generate a great amount of data at a very high data rate, both radar and optical. Real-time onboard processing can be the solution to reduce data downlink and management on ground. Radiometric, geometric, and atmospheric corrections of EO data as well as material/object detection in addition to the well-known needs for image compression and signal processing can be performed directly on board and the aim of QI2S project is to demonstrate this. QI2S, a concept prototype system for novel onboard image processing and image interpretation which has been designed, developed and validated in the framework of an EU FP7 project, targets these needs and makes a significant step towards exceeding current roadmaps of leading space agencies for future payload processors. The QI2S system features multiple chip components of the RC64, a novel rad-hard 64-core signal processing chip, which targets DSP performance of 75 GMACs (16bit), 150 GOPS and 38 single precision GFLOPS while dissipating less than 10 Watts. It integrates advanced DSP cores with a multibank shared memory and a hardware scheduler, also supporting DDR2/3 memory and twelve 3.125 Gbps full duplex high-speed serial links using SpaceFibre and other protocols. The processor is being developed within the European FP7 Framework Program and will be qualified to the highest space standards.

The Education of Serials Catalogers.

ERIC Educational Resources Information Center

Soper, Mary Ellen

1987-01-01

Reviews surveys of accredited library schools' efforts to prepare students to work with serials and practitioners' attitudes toward their formal serials education, and presents results of a 1986 survey of serials cataloging courses offered by library schools. Continuing education and the importance of special instruction for serials work are…

Soft Decision Analyzer

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin; Steele, Glen; Zucha, Joan; Schlesinger, Adam

2013-01-01

We describe the benefit of using closed-loop measurements for a radio receiver paired with a counterpart transmitter. We show that real-time analysis of the soft decision output of a receiver can provide rich and relevant insight far beyond the traditional hard-decision bit error rate (BER) test statistic. We describe a Soft Decision Analyzer (SDA) implementation for closed-loop measurements on single- or dual- (orthogonal) channel serial data communication links. The analyzer has been used to identify, quantify, and prioritize contributors to implementation loss in live-time during the development of software defined radios. This test technique gains importance as modern receivers are providing soft decision symbol synchronization as radio links are challenged to push more data and more protocol overhead through noisier channels, and software-defined radios (SDRs) use error-correction codes that approach Shannon's theoretical limit of performance.

European Non-Dissipative Bypass Switch For Li-Ion Batteries And Prospective

NASA Astrophysics Data System (ADS)

Pasquier, E.; Castric, AF.; Mosset, E.; Chandeneau, A.

2011-10-01

Li-ion batteries are made of cells or modules connected in series. In case one may be too weak or failed, it becomes necessary to remove it from the serial circuit. This is the by-pass operation which provides overcharge/open-circuitprotection,limitation of possible constraints linked to over- discharge/reversal/"self-short" and avoid to jeopardize rest of battery. One system is particularly adapted to Space Li-ion batteries: the "make before break" Single Pole Double Throw (SPDT) switch which avoids open- circuit on power circuit when correctly activated. This paper presents the component constraints, the development in the frame of ESA Artès 3 program up to its qualification, as well as the motorization approach linked to ECSS-E-30 (mechanical - Part 3: Mechanisms) and future opportunities of such system.

Software interface for high-speed readout of particle detectors based on the CoaXPress communication standard

NASA Astrophysics Data System (ADS)

Hejtmánek, M.; Neue, G.; Voleš, P.

2015-06-01

This article is devoted to the software design and development of a high-speed readout application used for interfacing particle detectors via the CoaXPress communication standard. The CoaXPress provides an asymmetric high-speed serial connection over a single coaxial cable. It uses a widely available 75 Ω BNC standard and can operate in various modes with a data throughput ranging from 1.25 Gbps up to 25 Gbps. Moreover, it supports a low speed uplink with a fixed bit rate of 20.833 Mbps, which can be used to control and upload configuration data to the particle detector. The CoaXPress interface is an upcoming standard in medical imaging, therefore its usage promises long-term compatibility and versatility. This work presents an example of how to develop DAQ system for a pixel detector. For this purpose, a flexible DAQ card was developed using the XILINX Spartan 6 FPGA. The DAQ card is connected to the framegrabber FireBird CXP6 Quad, which is plugged in the PCI Express bus of the standard PC. The data transmission was performed between the FPGA and framegrabber card via the standard coaxial cable in communication mode with a bit rate of 3.125 Gbps. Using the Medipix2 Quad pixel detector, the framerate of 100 fps was achieved. The front-end application makes use of the FireBird framegrabber software development kit and is suitable for data acquisition as well as control of the detector through the registers implemented in the FPGA.

Universal Visual Features Might Be Necessary for Fluent Reading. A Longitudinal Study of Visual Reading in Braille and Cyrillic Alphabets

PubMed Central

Bola, Łukasz; Radziun, Dominika; Siuda-Krzywicka, Katarzyna; Sowa, Joanna E.; Paplińska, Małgorzata; Sumera, Ewa; Szwed, Marcin

2017-01-01

It has been hypothesized that efficient reading is possible because all reading scripts have been matched, through cultural evolution, to the natural capabilities of the visual cortex. This matching has resulted in all scripts being made of line-junctions, such as T, X, or L. Our aim was to test a critical prediction of this hypothesis: visual reading in an atypical script that is devoid of line-junctions (such as the Braille alphabet read visually) should be much less efficient than reading in a “normal” script (e.g., Cyrillic). Using a lexical decision task, we examined Visual Braille reading speed and efficiency in sighted Braille teachers. As a control, we tested learners of a natural visual script, Cyrillic. Both groups participated in a two semester course of either visual Braille or Russian while their reading speed and accuracy was tested at regular intervals. The results show that visual Braille reading is slow, prone to errors and highly serial, even in Braille readers with years of prior reading experience. Although subjects showed some improvements in their visual Braille reading accuracy and speed following the course, the effect of word length on reading speed (typically observed in beginning readers) was remained very sizeable through all testing sessions. These results are in stark contrast to Cyrillic, a natural script, where only 3 months of learning were sufficient to achieve relative proficiency. Taken together, these results suggest that visual features such as line junctions and their combinations might be necessary for efficient reading. PMID:28421027

Universal Visual Features Might Be Necessary for Fluent Reading. A Longitudinal Study of Visual Reading in Braille and Cyrillic Alphabets.

PubMed

Bola, Łukasz; Radziun, Dominika; Siuda-Krzywicka, Katarzyna; Sowa, Joanna E; Paplińska, Małgorzata; Sumera, Ewa; Szwed, Marcin

2017-01-01

It has been hypothesized that efficient reading is possible because all reading scripts have been matched, through cultural evolution, to the natural capabilities of the visual cortex. This matching has resulted in all scripts being made of line-junctions, such as T, X, or L. Our aim was to test a critical prediction of this hypothesis: visual reading in an atypical script that is devoid of line-junctions (such as the Braille alphabet read visually) should be much less efficient than reading in a "normal" script (e.g., Cyrillic). Using a lexical decision task, we examined Visual Braille reading speed and efficiency in sighted Braille teachers. As a control, we tested learners of a natural visual script, Cyrillic. Both groups participated in a two semester course of either visual Braille or Russian while their reading speed and accuracy was tested at regular intervals. The results show that visual Braille reading is slow, prone to errors and highly serial, even in Braille readers with years of prior reading experience. Although subjects showed some improvements in their visual Braille reading accuracy and speed following the course, the effect of word length on reading speed (typically observed in beginning readers) was remained very sizeable through all testing sessions. These results are in stark contrast to Cyrillic, a natural script, where only 3 months of learning were sufficient to achieve relative proficiency. Taken together, these results suggest that visual features such as line junctions and their combinations might be necessary for efficient reading.

Multifractal analysis of the time series of daily means of wind speed in complex regions

NASA Astrophysics Data System (ADS)

Laib, Mohamed; Golay, Jean; Telesca, Luciano; Kanevski, Mikhail

2018-04-01

In this paper, we applied the multifractal detrended fluctuation analysis to the daily means of wind speed measured by 119 weather stations distributed over the territory of Switzerland. The analysis was focused on the inner time fluctuations of wind speed, which could be more linked with the local conditions of the highly varying topography of Switzerland. Our findings point out to a persistent behaviour of all the measured wind speed series (indicated by a Hurst exponent significantly larger than 0.5), and to a high multifractality degree indicating a relative dominance of the large fluctuations in the dynamics of wind speed, especially in the Swiss plateau, which is comprised between the Jura and Alp mountain ranges. The study represents a contribution to the understanding of the dynamical mechanisms of wind speed variability in mountainous regions.

The Impact of Language Opacity and Proficiency on Reading Strategies in Bilinguals: An Eye Movement Study.

PubMed

de León Rodríguez, Diego; Buetler, Karin A; Eggenberger, Noëmi; Laganaro, Marina; Nyffeler, Thomas; Annoni, Jean-Marie; Müri, René M

2016-01-01

Reading strategies vary across languages according to orthographic depth - the complexity of the grapheme in relation to phoneme conversion rules - notably at the level of eye movement patterns. We recently demonstrated that a group of early bilinguals, who learned both languages equally under the age of seven, presented a first fixation location (FFL) closer to the beginning of words when reading in German as compared with French. Since German is known to be orthographically more transparent than French, this suggested that different strategies were being engaged depending on the orthographic depth of the used language. Opaque languages induce a global reading strategy, and transparent languages force a local/serial strategy. Thus, pseudo-words were processed using a local strategy in both languages, suggesting that the link between word forms and their lexical representation may also play a role in selecting a specific strategy. In order to test whether corresponding effects appear in late bilinguals with low proficiency in their second language (L2), we present a new study in which we recorded eye movements while two groups of late German-French and French-German bilinguals read aloud isolated French and German words and pseudo-words. Since, a transparent reading strategy is local and serial, with a high number of fixations per stimuli, and the level of the bilingual participants' L2 is low, the impact of language opacity should be observed in L1. We therefore predicted a global reading strategy if the bilinguals' L1 was French (FFL close to the middle of the stimuli with fewer fixations per stimuli) and a local and serial reading strategy if it was German. Thus, the L2 of each group, as well as pseudo-words, should also require a local and serial reading strategy. Our results confirmed these hypotheses, suggesting that global word processing is only achieved by bilinguals with an opaque L1 when reading in an opaque language; the low level in the L2 gives way to a local and serial reading strategy. These findings stress the fact that reading behavior is influenced not only by the linguistic mode but also by top-down factors, such as readers' proficiency.

IFLA General Conference, 1986. Collections and Services Division. Section: Serial Publications. Papers.

ERIC Educational Resources Information Center

International Federation of Library Associations and Institutions, The Hague (Netherlands).

Papers on serial publications presented at the 1986 International Federation of Library Associations (IFLA) conference include: (1) "Scenario for Microcomputer-Based Serials Cataloging from ISDS (International Serials Data System) Records--New Horizons for Serial Librarianship in the Developing Countries by the Availability of Adequate…

Union Listing via OCLC's Serials Control Subsystem.

ERIC Educational Resources Information Center

O'Malley, Terrence J.

1984-01-01

Describes library use of Conversion of Serials Project's (CONSER) online national machine-readable database for serials to create online union lists of serials via OCLC's Serial Control Subsystem. Problems in selection of appropriate, accurate, and authenticated records and prospects for the future are discussed. Twenty sources and sample records…

The Circulation Analysis of Serial Use: Numbers Game or Key to Service?

PubMed Central

Raisig, L. Miles

1967-01-01

The conventionally erected and reported circulation analysis of serial use in the individual and the feeder library is found to be statistically invalid and misleading, since it measures neither the intellectual use of the serial's contents nor the physical handlings of serial units, and is nonrepresentative of the in-depth library use of serials. It fails utterly to report or even to suggest the relation of intralibrary and interlibrary serial resources. The actual mechanics of the serial use analysis, and the active variables in the library situation which affect serial use, are demonstrated in a simulated analysis and are explained at length. A positive design is offered for the objective gathering and reporting of data on the local intellectual use and physical handling of serials and the relating of resources. Data gathering in the feeder library, and implications for the extension of the feeder library's resources, are discussed. PMID:6055863

The Integrity of the Corpus Callosum Mitigates the Impact of Blood Pressure on the Ventral Attention Network and Information Processing Speed in Healthy Adults

PubMed Central

Wong, Nichol M. L.; Ma, Ernie Po-Wing; Lee, Tatia M. C.

2017-01-01

Hypertension is a risk factor for cognitive impairment in older age. However, evidence of the neural basis of the relationship between the deterioration of cognitive function and elevated blood pressure is sparse. Based on previous research, we speculate that variations in brain connectivity are closely related to elevated blood pressure even before the onset of clinical conditions and apparent cognitive decline in individuals over 60 years of age. Forty cognitively healthy adults were recruited. Each received a blood pressure test before and after the cognitive assessment in various domains. Diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rsfMRI) data were collected. Our findings confirm that elevated blood pressure is associated with brain connectivity variations in cognitively healthy individuals. The integrity of the splenium of the corpus callosum is closely related to individual differences in systolic blood pressure. In particular, elevated systolic blood pressure is related to resting-state ventral attention network (VAN) and information processing speed. Serial mediation analyses have further revealed that lower integrity of the splenium statistically predicts elevated systolic blood pressure, which in turn predicts weakened functional connectivity (FC) within the VAN and eventually poorer processing speed. The current study sheds light on how neural correlates are involved in the impact of elevated blood pressure on cognitive functioning. PMID:28484386

An Active RBSE Framework to Generate Optimal Stimulus Sequences in a BCI for Spelling

NASA Astrophysics Data System (ADS)

Moghadamfalahi, Mohammad; Akcakaya, Murat; Nezamfar, Hooman; Sourati, Jamshid; Erdogmus, Deniz

2017-10-01

A class of brain computer interfaces (BCIs) employs noninvasive recordings of electroencephalography (EEG) signals to enable users with severe speech and motor impairments to interact with their environment and social network. For example, EEG based BCIs for typing popularly utilize event related potentials (ERPs) for inference. Presentation paradigm design in current ERP-based letter by letter typing BCIs typically query the user with an arbitrary subset characters. However, the typing accuracy and also typing speed can potentially be enhanced with more informed subset selection and flash assignment. In this manuscript, we introduce the active recursive Bayesian state estimation (active-RBSE) framework for inference and sequence optimization. Prior to presentation in each iteration, rather than showing a subset of randomly selected characters, the developed framework optimally selects a subset based on a query function. Selected queries are made adaptively specialized for users during each intent detection. Through a simulation-based study, we assess the effect of active-RBSE on the performance of a language-model assisted typing BCI in terms of typing speed and accuracy. To provide a baseline for comparison, we also utilize standard presentation paradigms namely, row and column matrix presentation paradigm and also random rapid serial visual presentation paradigms. The results show that utilization of active-RBSE can enhance the online performance of the system, both in terms of typing accuracy and speed.

Full scale wind tunnel investigation of a bearingless main helicopter rotor. [Ames 40 by 80 foot wind tunnel test using the BO-105 helicopter

NASA Technical Reports Server (NTRS)

1980-01-01

A stability test program was conducted to determine the effects of airspeed, collective pitch, rotor speed and shaft angle on stability and loads at speeds beyond that attained in the BMR/BO-105 flight test program. Loads and performance data were gathered at forward speeds up to 165 knots. The effect of cyclic pitch perturbations on rotor response was investigated at simulated level flight conditions. Two configuration variations were tested for their effect on stability. One variable was the control system stiffness. An axially softer pitch link was installed in place of the standard BO-105 pitch link. The second variation was the addition of elastomeric damper strips to increase the structural damping. The BMR was stable at all conditions tested. At fixed collective pitch, shaft angle and rotor speed, damping generally increased between hover and 60 knots, remained relatively constant from 60 to 90 knots, then decreased above 90 knots. Analytical predictions are in good agreement with test data up to 90 knots, but the trend of decreasing damping above 90 knots is contrary to the theory.

Serials Automation for San Jose State University Library.

ERIC Educational Resources Information Center

Liu, Susana J.

This study (1) examines the university's serials system and identifies its problems; (2) analyzes the current manual operations in the serials department, with emphasis on the serials check-in system; and (3) determines whether or not computerization of some or all of the serials subsystems would improve the department's internal effectiveness and…

A Simulation Model Of A Picture Archival And Communication System

NASA Astrophysics Data System (ADS)

D'Silva, Vijay; Perros, Harry; Stockbridge, Chris

1988-06-01

A PACS architecture was simulated to quantify its performance. The model consisted of reading stations, acquisition nodes, communication links, a database management system, and a storage system consisting of magnetic and optical disks. Two levels of storage were simulated, a high-speed magnetic disk system for short term storage, and optical disk jukeboxes for long term storage. The communications link was a single bus via which image data were requested and delivered. Real input data to the simulation model were obtained from surveys of radiology procedures (Bowman Gray School of Medicine). From these the following inputs were calculated: - the size of short term storage necessary - the amount of long term storage required - the frequency of access of each store, and - the distribution of the number of films requested per diagnosis. The performance measures obtained were - the mean retrieval time for an image, - mean queue lengths, and - the utilization of each device. Parametric analysis was done for - the bus speed, - the packet size for the communications link, - the record size on the magnetic disk, - compression ratio, - influx of new images, - DBMS time, and - diagnosis think times. Plots give the optimum values for those values of input speed and device performance which are sufficient to achieve subsecond image retrieval times

Force reflecting hand controller

NASA Technical Reports Server (NTRS)

Mcaffee, Douglas A. (Inventor); Snow, Edward R. (Inventor); Townsend, William T. (Inventor)

1993-01-01

A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs.

A computerized aircraft battery servicing facility

NASA Technical Reports Server (NTRS)

Glover, Richard D.

1992-01-01

The latest upgrade to the Aerospace Energy Systems Laboratory (AESL) is described. The AESL is a distributed digital system consisting of a central system and battery servicing stations connected by a high-speed serial data bus. The entire system is located in two adjoining rooms; the bus length is approximately 100 ft. Each battery station contains a digital processor, data acquisition, floppy diskette data storage, and operator interfaces. The operator initiates a servicing task and thereafter the battery station monitors the progress of the task and terminates it at the appropriate time. The central system provides data archives, manages the data bus, and provides a timeshare interface for multiple users. The system also hosts software production tools for the battery stations and the central system.

Multi-brain fusion and applications to intelligence analysis

NASA Astrophysics Data System (ADS)

Stoica, A.; Matran-Fernandez, A.; Andreou, D.; Poli, R.; Cinel, C.; Iwashita, Y.; Padgett, C.

2013-05-01

In a rapid serial visual presentation (RSVP) images are shown at an extremely rapid pace. Yet, the images can still be parsed by the visual system to some extent. In fact, the detection of specific targets in a stream of pictures triggers a characteristic electroencephalography (EEG) response that can be recognized by a brain-computer interface (BCI) and exploited for automatic target detection. Research funded by DARPA's Neurotechnology for Intelligence Analysts program has achieved speed-ups in sifting through satellite images when adopting this approach. This paper extends the use of BCI technology from individual analysts to collaborative BCIs. We show that the integration of information in EEGs collected from multiple operators results in performance improvements compared to the single-operator case.

Solution of a large hydrodynamic problem using the STAR-100 computer

NASA Technical Reports Server (NTRS)

Weilmuenster, K. J.; Howser, L. M.

1976-01-01

A representative hydrodynamics problem, the shock initiated flow over a flat plate, was used for exploring data organizations and program structures needed to exploit the STAR-100 vector processing computer. A brief description of the problem is followed by a discussion of how each portion of the computational process was vectorized. Finally, timings of different portions of the program are compared with equivalent operations on serial machines. The speed up of the STAR-100 over the CDC 6600 program is shown to increase as the problem size increases. All computations were carried out on a CDC 6600 and a CDC STAR 100, with code written in FORTRAN for the 6600 and in STAR FORTRAN for the STAR 100.

Adaptation and optimization of a line-by-line radiative transfer program for the STAR-100 (STARSMART)

NASA Technical Reports Server (NTRS)

Rarig, P. L.

1980-01-01

A program to calculate upwelling infrared radiation was modified to operate efficiently on the STAR-100. The modified software processes specific test cases significantly faster than the initial STAR-100 code. For example, a midlatitude summer atmospheric model is executed in less than 2% of the time originally required on the STAR-100. Furthermore, the optimized program performs extra operations to save the calculated absorption coefficients. Some of the advantages and pitfalls of virtual memory and vector processing are discussed along with strategies used to avoid loss of accuracy and computing power. Results from the vectorized code, in terms of speed, cost, and relative error with respect to serial code solutions are encouraging.

Redundancy management of multiple KT-70 inertial measurement units applicable to the space shuttle

NASA Technical Reports Server (NTRS)

Cook, L. J.

1975-01-01

Results of an investigation of velocity failure detection and isolation for 3 inertial measuring units (IMU) and 2 inertial measuring units (IMU) configurations are presented. The failure detection and isolation algorithm performance was highly successful and most types of velocity errors were detected and isolated. The failure detection and isolation algorithm also included attitude FDI but was not evaluated because of the lack of time and low resolution in the gimbal angle synchro outputs. The shuttle KT-70 IMUs will have dual-speed resolvers and high resolution gimbal angle readouts. It was demonstrated by these tests that a single computer utilizing a serial data bus can successfully control a redundant 3-IMU system and perform FDI.

Method for star identification using neural networks

NASA Astrophysics Data System (ADS)

Lindsey, Clark S.; Lindblad, Thomas; Eide, Age J.

1997-04-01

Identification of star constellations with an onboard star tracker provides the highest precision of all attitude determination techniques for spacecraft. A method for identification of star constellations inspired by neural network (NNW) techniques is presented. It compares feature vectors derived from histograms of distances to multiple stars around the unknown star. The NNW method appears most robust with respect to position noise and would require a smaller database than conventional methods, especially for small fields of view. The neural network method is quite slow when performed on a sequential (serial) processor, but would provide very high speed if implemented in special hardware. Such hardware solutions could also yield lower low weight and low power consumption, both important features for small satellites.

A wideband-PCM recorder for the Space Shuttle orbiter

NASA Technical Reports Server (NTRS)

Petit, R. D.

1976-01-01

The Shuttle wideband-PCM recorder accomplishes recording on up to 14 data tracks with analog or digital data inputs. FM multiplexed analog frequencies of up to 2 MHz and digital rates of 1 Mb/s are accommodated at a tape speed of 120 in/s. Recording time in analog mode varies between 4 min for 2 MHz data to 80 min for 100 kHz data. The total digital data storage is 3.44 x 10 to the 9th bits with recording times from 1 hour for 1 Mb/s to 19 hours for 50 Kb/s data in the serial track switching mode. A versatile command decoder and control interface are used for eight primary modes of operation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Citterio, M.; Camplani, A.; Cannon, M.

SRAM based Field Programmable Gate Arrays (FPGAs) have been rarely used in High Energy Physics (HEP) due to their sensitivity to radiation. The last generation of commercial FPGAs based on 28 nm feature size and on Silicon On Insulator (SOI) technologies are more tolerant to radiation to the level that their use in front-end electronics is now feasible. FPGAs provide re-programmability, high-speed computation and fast data transmission through the embedded serial transceivers. They could replace custom application specific integrated circuits in front end electronics in locations with moderate radiation field. Finally, the use of a FPGA in HEP experiments ismore » only limited by our ability to mitigate single event effects induced by the high energy hadrons present in the radiation field.« less

The integration of laser communication and ranging

NASA Astrophysics Data System (ADS)

Xu, Mengmeng; Sun, Jianfeng; Zhou, Yu; Zhang, Bo; Zhang, Guo; Li, Guangyuan; He, Hongyu; Lao, Chenzhe

2017-08-01

The method to realize the integration of laser communication and ranging is proposed in this paper. In the transmitter of two places, the ranging codes with uniqueness, good autocorrelation and cross-correlation properties are embed in the communication data and the encoded with the communication data to realize serial communication. And then the encoded data are modulated and send to each other, which can realize high speed two one-way laser communication. At the receiver, we can get the received ranging code after the demodulation, decoding and clock recovery. The received ranging codes and the local ranging codes do the autocorrelation to get a roughly range, while the phase difference between the local clock and the recovery clock to achieve the precision of the distance.

ARINC 818 adds capabilities for high-speed sensors and systems

NASA Astrophysics Data System (ADS)

Keller, Tim; Grunwald, Paul

2014-06-01

ARINC 818, titled Avionics Digital Video Bus (ADVB), is the standard for cockpit video that has gained wide acceptance in both the commercial and military cockpits including the Boeing 787, the A350XWB, the A400M, the KC- 46A and many others. Initially conceived of for cockpit displays, ARINC 818 is now propagating into high-speed sensors, such as infrared and optical cameras due to its high-bandwidth and high reliability. The ARINC 818 specification that was initially release in the 2006 and has recently undergone a major update that will enhance its applicability as a high speed sensor interface. The ARINC 818-2 specification was published in December 2013. The revisions to the specification include: video switching, stereo and 3-D provisions, color sequential implementations, regions of interest, data-only transmissions, multi-channel implementations, bi-directional communication, higher link rates to 32Gbps, synchronization signals, options for high-speed coax interfaces and optical interface details. The additions to the specification are especially appealing for high-bandwidth, multi sensor systems that have issues with throughput bottlenecks and SWaP concerns. ARINC 818 is implemented on either copper or fiber optic high speed physical layers, and allows for time multiplexing multiple sensors onto a single link. This paper discusses each of the new capabilities in the ARINC 818-2 specification and the benefits for ISR and countermeasures implementations, several examples are provided.

A novel approach to estimate emissions from large transportation networks: Hierarchical clustering-based link-driving-schedules for EPA-MOVES using dynamic time warping measures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aziz, H. M. Abdul; Ukkusuri, Satish V.

We present that EPA-MOVES (Motor Vehicle Emission Simulator) is often integrated with traffic simulators to assess emission levels of large-scale urban networks with signalized intersections. High variations in speed profiles exist in the context of congested urban networks with signalized intersections. The traditional average-speed-based emission estimation technique with EPA-MOVES provides faster execution while underestimates the emissions in most cases because of ignoring the speed variation at congested networks with signalized intersections. In contrast, the atomic second-by-second speed profile (i.e., the trajectory of each vehicle)-based technique provides accurate emissions at the cost of excessive computational power and time. We addressed thismore » issue by developing a novel method to determine the link-driving-schedules (LDSs) for the EPA-MOVES tool. Our research developed a hierarchical clustering technique with dynamic time warping similarity measures (HC-DTW) to find the LDS for EPA-MOVES that is capable of producing emission estimates better than the average-speed-based technique with execution time faster than the atomic speed profile approach. We applied the HC-DTW on a sample data from a signalized corridor and found that HC-DTW can significantly reduce computational time without compromising the accuracy. The developed technique in this research can substantially contribute to the EPA-MOVES-based emission estimation process for large-scale urban transportation network by reducing the computational time with reasonably accurate estimates. This method is highly appropriate for transportation networks with higher variation in speed such as signalized intersections. Lastly, experimental results show error difference ranging from 2% to 8% for most pollutants except PM 10.« less

A novel approach to estimate emissions from large transportation networks: Hierarchical clustering-based link-driving-schedules for EPA-MOVES using dynamic time warping measures

DOE PAGES

Aziz, H. M. Abdul; Ukkusuri, Satish V.

2017-06-29

We present that EPA-MOVES (Motor Vehicle Emission Simulator) is often integrated with traffic simulators to assess emission levels of large-scale urban networks with signalized intersections. High variations in speed profiles exist in the context of congested urban networks with signalized intersections. The traditional average-speed-based emission estimation technique with EPA-MOVES provides faster execution while underestimates the emissions in most cases because of ignoring the speed variation at congested networks with signalized intersections. In contrast, the atomic second-by-second speed profile (i.e., the trajectory of each vehicle)-based technique provides accurate emissions at the cost of excessive computational power and time. We addressed thismore » issue by developing a novel method to determine the link-driving-schedules (LDSs) for the EPA-MOVES tool. Our research developed a hierarchical clustering technique with dynamic time warping similarity measures (HC-DTW) to find the LDS for EPA-MOVES that is capable of producing emission estimates better than the average-speed-based technique with execution time faster than the atomic speed profile approach. We applied the HC-DTW on a sample data from a signalized corridor and found that HC-DTW can significantly reduce computational time without compromising the accuracy. The developed technique in this research can substantially contribute to the EPA-MOVES-based emission estimation process for large-scale urban transportation network by reducing the computational time with reasonably accurate estimates. This method is highly appropriate for transportation networks with higher variation in speed such as signalized intersections. Lastly, experimental results show error difference ranging from 2% to 8% for most pollutants except PM 10.« less

SR-71 - In-flight Close-up from Tanker

NASA Technical Reports Server (NTRS)

1994-01-01

This extreme close-up of the SR-71B operated by NASA's Dryden Flight Research Center, Edwards, California, gives an unusual view of the twin cockpit of Dryden's SR-71B, NASA 831, and its helmeted crew members. The photo was taken from an Air Force tanker refueling the Blackbird during a 1994 flight. The Mach 3 Blackbird aircraft were loaned to NASA by the U.S. Air Force for high-speed, high-altitude aeronautical research. Capable of flying more than 2200 mph and at altitudes of over 85,000 feet, they are excellent platforms for research and experiments in aerodynamics, propulsion, structures, thermal protection materials, atmospheric studies, and sonic boom characterization. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

Serials Management: A Practical Guide. Frontiers of Access to Library Materials No. 3.

ERIC Educational Resources Information Center

Chen, Chiou-Sen Dora

This book advises librarians, paraprofessional library supervisors, and library school students on problems unique to the management of serials. Chapter 1 explains the character and publication patterns of serials. Chapter 2 discusses the scope and the organizational structure of serials management, and the role of the serials manager. Chapter 3…

Mechanistic simulation of normal-tissue damage in radiotherapy—implications for dose-volume analyses

NASA Astrophysics Data System (ADS)

Rutkowska, Eva; Baker, Colin; Nahum, Alan

2010-04-01

A radiobiologically based 3D model of normal tissue has been developed in which complications are generated when 'irradiated'. The aim is to provide insight into the connection between dose-distribution characteristics, different organ architectures and complication rates beyond that obtainable with simple DVH-based analytical NTCP models. In this model the organ consists of a large number of functional subunits (FSUs), populated by stem cells which are killed according to the LQ model. A complication is triggered if the density of FSUs in any 'critical functioning volume' (CFV) falls below some threshold. The (fractional) CFV determines the organ architecture and can be varied continuously from small (series-like behaviour) to large (parallel-like). A key feature of the model is its ability to account for the spatial dependence of dose distributions. Simulations were carried out to investigate correlations between dose-volume parameters and the incidence of 'complications' using different pseudo-clinical dose distributions. Correlations between dose-volume parameters and outcome depended on characteristics of the dose distributions and on organ architecture. As anticipated, the mean dose and V20 correlated most strongly with outcome for a parallel organ, and the maximum dose for a serial organ. Interestingly better correlation was obtained between the 3D computer model and the LKB model with dose distributions typical for serial organs than with those typical for parallel organs. This work links the results of dose-volume analyses to dataset characteristics typical for serial and parallel organs and it may help investigators interpret the results from clinical studies.

Organizational Learning Strategies and Verbal Memory Deficits in Bipolar Disorder.

PubMed

Nitzburg, George C; Cuesta-Diaz, Armando; Ospina, Luz H; Russo, Manuela; Shanahan, Megan; Perez-Rodriguez, Mercedes; Larsen, Emmett; Mulaimovic, Sandra; Burdick, Katherine E

2017-04-01

Verbal memory (VM) impairment is prominent in bipolar disorder (BD) and is linked to functional outcomes. However, the intricacies of VM impairment have not yet been studied in a large sample of BD patients. Moreover, some have proposed VM deficits that may be mediated by organizational strategies, such as semantic or serial clustering. Thus, the exact nature of VM break-down in BD patients is not well understood, limiting remediation efforts. We investigated the intricacies of VM deficits in BD patients versus healthy controls (HCs) and examined whether verbal learning differences were mediated by use of clustering strategies. The California Verbal Learning Test (CVLT) was administered to 113 affectively stable BD patients and 106 HCs. We compared diagnostic groups on all CVLT indices and investigated whether group differences in verbal learning were mediated by clustering strategies. Although BD patients showed significantly poorer attention, learning, and memory, these indices were only mildly impaired. However, BD patients evidenced poorer use of effective learning strategies and lower recall consistency, with these indices falling in the moderately impaired range. Moreover, relative reliance on semantic clustering fully mediated the relationship between diagnostic category and verbal learning, while reliance on serial clustering partially mediated this relationship. VM deficits in affectively stable bipolar patients were widespread but were generally mildly impaired. However, patients displayed inadequate use of organizational strategies with clear separation from HCs on semantic and serial clustering. Remediation efforts may benefit from education about mnemonic devices or "chunking" techniques to attenuate VM deficits in BD. (JINS, 2017, 23, 358-366).

Ten-Year Climatology of Summertime Diurnal Rainfall Rate Over the Conterminous U.S.

NASA Technical Reports Server (NTRS)

Matsui, Toshihisa; Mocko, David; Lee, Myong-In; Tao, Wei-Kuo; Suarez, Max J.; Pielke, Roger A., Sr.

2010-01-01

Diurnal cycles of summertime rainfall rates are examined over the conterminous United States, using radar-gauge assimilated hourly rainfall data. As in earlier studies, rainfall diurnal composites show a well-defined region of rainfall propagation over the Great Plains and an afternoon maximum area over the south and eastern portion of the United States. Zonal phase speeds of rainfall in three different small domains are estimated, and rainfall propagation speeds are compared with background zonal wind speeds. Unique rainfall propagation speeds in three different regions can be explained by the evolution of latent-heat theory linked to the convective available potential energy, than by gust-front induced or gravity wave propagation mechanisms.

Cosmological bimetric model with interacting positive and negative masses and two different speeds of light, in agreement with the observed acceleration of the Universe

NASA Astrophysics Data System (ADS)

Petit, J. P.; D'Agostini, G.

2014-10-01

An extension of a previously published model of a bimetric Universe is presented, where the speeds of light associated to positive and negative mass species are different. As shown earlier, the asymmetry of the model explains the acceleration of the positive species, while the negative one slows down. Asymmetry affects scale factors linked to lengths, times and speeds of light; so that if a mass inversion of a craft can be achieved, then interstellar travels would become non-impossible at a velocity less than the speed of light of the negative sector, and possibly much higher than that of the positive sector.