Small Acute Benefits of 4 Weeks Processing Speed Training Games on Processing Speed and Inhibition Performance and Depressive Mood in the Healthy Elderly People: Evidence from a Randomized Control Trial

PubMed Central

Nouchi, Rui; Saito, Toshiki; Nouchi, Haruka; Kawashima, Ryuta

2016-01-01

Background: Processing speed training using a 1-year intervention period improves cognitive functions and emotional states of elderly people. Nevertheless, it remains unclear whether short-term processing speed training such as 4 weeks can benefit elderly people. This study was designed to investigate effects of 4 weeks of processing speed training on cognitive functions and emotional states of elderly people. Methods: We used a single-blinded randomized control trial (RCT). Seventy-two older adults were assigned randomly to two groups: a processing speed training game (PSTG) group and knowledge quiz training game (KQTG) group, an active control group. In PSTG, participants were asked to play PSTG (12 processing speed games) for 15 min, during five sessions per week, for 4 weeks. In the KQTG group, participants were asked to play KQTG (four knowledge quizzes) for 15 min, during five sessions per week, for 4 weeks. We measured several cognitive functions and emotional states before and after the 4 week intervention period. Results: Our results revealed that PSTG improved performances in processing speed and inhibition compared to KQTG, but did not improve performance in reasoning, shifting, short term/working memory, and episodic memory. Moreover, PSTG reduced the depressive mood score as measured by the Profile of Mood State compared to KQTG during the 4 week intervention period, but did not change other emotional measures. Discussion: This RCT first provided scientific evidence related to small acute benefits of 4 week PSTG on processing speed, inhibition, and depressive mood in healthy elderly people. We discuss possible mechanisms for improvements in processing speed and inhibition and reduction of the depressive mood. Trial registration: This trial was registered in The University Hospital Medical Information Network Clinical Trials Registry (UMIN000022250). PMID:28066229

Small Acute Benefits of 4 Weeks Processing Speed Training Games on Processing Speed and Inhibition Performance and Depressive Mood in the Healthy Elderly People: Evidence from a Randomized Control Trial.

PubMed

Nouchi, Rui; Saito, Toshiki; Nouchi, Haruka; Kawashima, Ryuta

2016-01-01

Background: Processing speed training using a 1-year intervention period improves cognitive functions and emotional states of elderly people. Nevertheless, it remains unclear whether short-term processing speed training such as 4 weeks can benefit elderly people. This study was designed to investigate effects of 4 weeks of processing speed training on cognitive functions and emotional states of elderly people. Methods: We used a single-blinded randomized control trial (RCT). Seventy-two older adults were assigned randomly to two groups: a processing speed training game (PSTG) group and knowledge quiz training game (KQTG) group, an active control group. In PSTG, participants were asked to play PSTG (12 processing speed games) for 15 min, during five sessions per week, for 4 weeks. In the KQTG group, participants were asked to play KQTG (four knowledge quizzes) for 15 min, during five sessions per week, for 4 weeks. We measured several cognitive functions and emotional states before and after the 4 week intervention period. Results: Our results revealed that PSTG improved performances in processing speed and inhibition compared to KQTG, but did not improve performance in reasoning, shifting, short term/working memory, and episodic memory. Moreover, PSTG reduced the depressive mood score as measured by the Profile of Mood State compared to KQTG during the 4 week intervention period, but did not change other emotional measures. Discussion: This RCT first provided scientific evidence related to small acute benefits of 4 week PSTG on processing speed, inhibition, and depressive mood in healthy elderly people. We discuss possible mechanisms for improvements in processing speed and inhibition and reduction of the depressive mood. Trial registration: This trial was registered in The University Hospital Medical Information Network Clinical Trials Registry (UMIN000022250).

Apathy and Reduced Speed of Processing Underlie Decline in Verbal Fluency following DBS.

PubMed

Foley, Jennifer A; Foltynie, Tom; Zrinzo, Ludvic; Hyam, Jonathan A; Limousin, Patricia; Cipolotti, Lisa

2017-01-01

Objective . Reduced verbal fluency is a strikingly uniform finding following deep brain stimulation (DBS) for Parkinson's disease (PD). The precise cognitive mechanism underlying this reduction remains unclear, but theories have suggested reduced motivation, linguistic skill, and/or executive function. It is of note, however, that previous reports have failed to consider the potential role of any changes in speed of processing. Thus, the aim of this study was to examine verbal fluency changes with a particular focus on the role of cognitive speed. Method . In this study, 28 patients with PD completed measures of verbal fluency, motivation, language, executive functioning, and speed of processing, before and after DBS. Results . As expected, there was a marked decline in verbal fluency but also in a timed test of executive functions and two measures of speed of processing. Verbal fluency decline was associated with markers of linguistic and executive functioning, but not after speed of processing was statistically controlled for. In contrast, greater decline in verbal fluency was associated with higher levels of apathy at baseline, which was not associated with changes in cognitive speed. Discussion . Reduced generativity and processing speed may account for the marked reduction in verbal fluency commonly observed following DBS.

Reading comprehension skills of young adults with childhood diagnoses of dyslexia.

PubMed

Ransby, Marilyn J; Swanson, H Lee

2003-01-01

This study explores the contribution of cognitive processes to comprehension skills in adults who suffered from childhood developmental dyslexia (CD). The performance of adults with CD (ages 17 to 23), chronological age-matched (CA) adults, and reading level-matched (RL) children was compared on measures of phonological processing, naming speed, working memory (WM), general knowledge, vocabulary, and comprehension. The results showed that adults with CD scored lower on measures of phonological processing, naming speed, WM, general knowledge, and vocabulary when compared to CA readers but were comparable to RL children on the majority of process measures. Phonological processing, naming speed, vocabulary, general knowledge, and listening comprehension contributed independent variance to reading comprehension accuracy, whereas WM, intelligence, phonological processing, and listening comprehension contributed independent variance to comprehension fluency. Adults with CD scored lower than CA adults and higher than RL children on measures of lexical processing, WM, and listening comprehension when word recognition and intelligence were partialed from the analysis. In summary, constraints in phonological processing and naming speed mediate only some of the influence of high-order processes on reading comprehension. Furthermore, adults with CD experience difficulties in WM, listening comprehension, and vocabulary independently of their word recognition problems and intellectual ability.

Predicting Word Reading and Comprehension with Executive Function and Speed Measures across Development: A Latent Variable Analysis

ERIC Educational Resources Information Center

Christopher, Micaela E.; Miyake, Akira; Keenan, Janice M.; Pennington, Bruce; DeFries, John C.; Wadsworth, Sally J.; Willcutt, Erik; Olson, Richard K.

2012-01-01

The present study explored whether different executive control and speed measures (working memory, inhibition, processing speed, and naming speed) independently predict individual differences in word reading and reading comprehension. Although previous studies suggest these cognitive constructs are important for reading, the authors analyze the…

Cultural Differences in the Development of Processing Speed

ERIC Educational Resources Information Center

Kail, Robert V.; McBride-Chang, Catherine; Ferrer, Emilio; Cho, Jeung-Ryeul; Shu, Hua

2013-01-01

The aim of the present work was to examine cultural differences in the development of speed of information processing. Four samples of US children ("N" = 509) and four samples of East Asian children ("N" = 661) completed psychometric measures of processing speed on two occasions. Analyses of the longitudinal data indicated…

Apathy and Reduced Speed of Processing Underlie Decline in Verbal Fluency following DBS

PubMed Central

Foltynie, Tom; Zrinzo, Ludvic; Hyam, Jonathan A.; Limousin, Patricia

2017-01-01

Objective. Reduced verbal fluency is a strikingly uniform finding following deep brain stimulation (DBS) for Parkinson's disease (PD). The precise cognitive mechanism underlying this reduction remains unclear, but theories have suggested reduced motivation, linguistic skill, and/or executive function. It is of note, however, that previous reports have failed to consider the potential role of any changes in speed of processing. Thus, the aim of this study was to examine verbal fluency changes with a particular focus on the role of cognitive speed. Method. In this study, 28 patients with PD completed measures of verbal fluency, motivation, language, executive functioning, and speed of processing, before and after DBS. Results. As expected, there was a marked decline in verbal fluency but also in a timed test of executive functions and two measures of speed of processing. Verbal fluency decline was associated with markers of linguistic and executive functioning, but not after speed of processing was statistically controlled for. In contrast, greater decline in verbal fluency was associated with higher levels of apathy at baseline, which was not associated with changes in cognitive speed. Discussion. Reduced generativity and processing speed may account for the marked reduction in verbal fluency commonly observed following DBS. PMID:28408788

High speed demodulation systems for fiber optic grating sensors

NASA Technical Reports Server (NTRS)

Udd, Eric (Inventor); Weisshaar, Andreas (Inventor)

2002-01-01

Fiber optic grating sensor demodulation systems are described that offer high speed and multiplexing options for both single and multiple parameter fiber optic grating sensors. To attain very high speeds for single parameter fiber grating sensors ratio techniques are used that allow a series of sensors to be placed in a single fiber while retaining high speed capability. These methods can be extended to multiparameter fiber grating sensors. Optimization of speeds can be obtained by minimizing the number of spectral peaks that must be processed and it is shown that two or three spectral peak measurements may in specific multiparameter applications offer comparable or better performance than processing four spectral peaks. Combining the ratio methods with minimization of peak measurements allows very high speed measurement of such important environmental effects as transverse strain and pressure.

The effects of mild and severe traumatic brain injury on speed of information processing as measured by the computerized tests of information processing (CTIP).

PubMed

Tombaugh, Tom N; Rees, Laura; Stormer, Peter; Harrison, Allyson G; Smith, Andra

2007-01-01

In spite of the fact that reaction time (RT) measures are sensitive to the effects of traumatic brain injury (TBI), few RT procedures have been developed for use in standard clinical evaluations. The computerized test of information processing (CTIP) [Tombaugh, T. N., & Rees, L. (2000). Manual for the computerized tests of information processing (CTIP). Ottawa, Ont.: Carleton University] was designed to measure the degree to which TBI decreases the speed at which information is processed. The CTIP consists of three computerized programs that progressively increase the amount of information that is processed. Results of the current study demonstrated that RT increased as the difficulty of the CTIP tests increased (known as the complexity effect), and as severity of injury increased (from mild to severe TBI). The current study also demonstrated the importance of selecting a non-biased measure of variability. Overall, findings suggest that the CTIP is an easy to administer and sensitive measure of information processing speed.

Prefrontal cortex activity during response selection predicts processing speed impairment in schizophrenia

PubMed Central

Woodward, Neil D.; Duffy-Alberto, Brittney; Karbasforoushan, Haleh

2014-01-01

Processing speed is the most impaired neuropsychological domain in schizophrenia and a robust predictor of functional outcome. Determining the specific cognitive operations underlying processing speed dysfunction and indentifying their neural correlates may assist in developing pro-cognitive interventions. Response selection, the process of mapping stimuli onto motor responses, correlates with neuropsychological tests of processing speed and may contribute to processing speed impairment in schizophrenia. This study investigated the relationship between behavioral and neural measures of response selection, and a neuropsychological index of processing speed in schizophrenia. 26 patients with schizophrenia and 21 healthy subjects underwent fMRI scanning during performance of 2 and 4-choice-reaction time (RT) tasks and completed the Wechsler Adult Intelligence Scale-III (WAIS) Processing Speed Index (PSI). Response selection, defined as RT slowing between 2 and 4-choice RT, was impaired in schizophrenia and correlated with psychometric processing speed. Greater activation of the dorsolateral prefrontal cortex (PFC) was observed in schizophrenia and correlated with poorer WAIS PSI scores. Deficient response selection and abnormal recruitment of the dorsolateral PFC during response selection contribute to processing speed impairment in schizophrenia. Interventions that improve response selection and normalize dorsolateral PFC function may improve processing speed in schizophrenia. PMID:23816240

Sampling optimization for high-speed weigh-in-motion measurements using in-pavement strain-based sensors

NASA Astrophysics Data System (ADS)

Zhang, Zhiming; Huang, Ying; Bridgelall, Raj; Palek, Leonard; Strommen, Robert

2015-06-01

Weigh-in-motion (WIM) measurement has been widely used for weight enforcement, pavement design, freight management, and intelligent transportation systems to monitor traffic in real-time. However, to use such sensors effectively, vehicles must exit the traffic stream and slow down to match their current capabilities. Hence, agencies need devices with higher vehicle passing speed capabilities to enable continuous weight measurements at mainline speeds. The current practices for data acquisition at such high speeds are fragmented. Deployment configurations and settings depend mainly on the experiences of operation engineers. To assure adequate data, most practitioners use very high frequency measurements that result in redundant samples, thereby diminishing the potential for real-time processing. The larger data memory requirements from higher sample rates also increase storage and processing costs. The field lacks a sampling design or standard to guide appropriate data acquisition of high-speed WIM measurements. This study develops the appropriate sample rate requirements as a function of the vehicle speed. Simulations and field experiments validate the methods developed. The results will serve as guidelines for future high-speed WIM measurements using in-pavement strain-based sensors.

Verbal Processing Speed and Executive Functioning in Long-Term Cochlear Implant Users

ERIC Educational Resources Information Center

AuBuchon, Angela M.; Pisoni, David B.; Kronenberger, William G.

2015-01-01

Purpose: The purpose of this study was to report how "verbal rehearsal speed" (VRS), a form of covert speech used to maintain verbal information in working memory, and another verbal processing speed measure, perceptual encoding speed, are related to 3 domains of executive function (EF) at risk in cochlear implant (CI) users: verbal…

Verbal Processing Speed and Executive Functioning in Long-Term Cochlear Implant Users

PubMed Central

Pisoni, David B.; Kronenberger, William G.

2015-01-01

Purpose The purpose of this study was to report how verbal rehearsal speed (VRS), a form of covert speech used to maintain verbal information in working memory, and another verbal processing speed measure, perceptual encoding speed, are related to 3 domains of executive function (EF) at risk in cochlear implant (CI) users: verbal working memory, fluency-speed, and inhibition-concentration. Method EF, speech perception, and language outcome measures were obtained from 55 prelingually deaf, long-term CI users and matched controls with normal hearing (NH controls). Correlational analyses were used to assess relations between VRS (articulation rate), perceptual encoding speed (digit and color naming), and the outcomes in each sample. Results CI users displayed slower verbal processing speeds than NH controls. Verbal rehearsal speed was related to 2 EF domains in the NH sample but was unrelated to EF outcomes in CI users. Perceptual encoding speed was related to all EF domains in both groups. Conclusions Verbal rehearsal speed may be less influential for EF quality in CI users than for NH controls, whereas rapid automatized labeling skills and EF are closely related in both groups. CI users may develop processing strategies in EF tasks that differ from the covert speech strategies routinely employed by NH individuals. PMID:25320961

Measure Guideline. Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings

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

Hunt, A.; Easley, S.

2012-05-01

This measure guideline evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provides a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

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…

Working memory span and motor and cognitive speed in schizophrenia.

PubMed

Brébion, Gildas; David, Anthony S; Jones, Hugh M; Pilowsky, Lyn S

2009-06-01

The aim of this study was to investigate the verbal working memory deficit and decrease of motor and cognitive speed in patients with schizophrenia, and to clarify their associations with negative and depressive symptomatology. Forty patients with schizophrenia and 41 healthy control individuals were administered the backward digit span to assess the working memory capacity, along with 3 tests of processing speed. Patients demonstrated reduced backward digit span, as well as decreased motor and cognitive speed. Regression analyses indicated that the backward digit span was associated with cognitive speed. It was not associated with either negative or depressive symptoms. Decreased processing speed was unrelated to negative symptoms, but the depression score was significantly associated with the cognitive speed measure. Working memory and processing speed seem to share a cognitive component. Depression, but not negative symptoms, affects processing speed, especially by decreasing cognitive speed.

Neural correlates of the difference between working memory speed and simple sensorimotor speed: an fMRI study.

PubMed

Takeuchi, Hikaru; Sugiura, Motoaki; Sassa, Yuko; Sekiguchi, Atsushi; Yomogida, Yukihito; Taki, Yasuyuki; Kawashima, Ryuta

2012-01-01

The difference between the speed of simple cognitive processes and the speed of complex cognitive processes has various psychological correlates. However, the neural correlates of this difference have not yet been investigated. In this study, we focused on working memory (WM) for typical complex cognitive processes. Functional magnetic resonance imaging data were acquired during the performance of an N-back task, which is a measure of WM for typical complex cognitive processes. In our N-back task, task speed and memory load were varied to identify the neural correlates responsible for the difference between the speed of simple cognitive processes (estimated from the 0-back task) and the speed of WM. Our findings showed that this difference was characterized by the increased activation in the right dorsolateral prefrontal cortex (DLPFC) and the increased functional interaction between the right DLPFC and right superior parietal lobe. Furthermore, the local gray matter volume of the right DLPFC was correlated with participants' accuracy during fast WM tasks, which in turn correlated with a psychometric measure of participants' intelligence. Our findings indicate that the right DLPFC and its related network are responsible for the execution of the fast cognitive processes involved in WM. Identified neural bases may underlie the psychometric differences between the speed with which subjects perform simple cognitive tasks and the speed with which subjects perform more complex cognitive tasks, and explain the previous traditional psychological findings.

Wind speed vector restoration algorithm

NASA Astrophysics Data System (ADS)

Baranov, Nikolay; Petrov, Gleb; Shiriaev, Ilia

2018-04-01

Impulse wind lidar (IWL) signal processing software developed by JSC «BANS» recovers full wind speed vector by radial projections and provides wind parameters information up to 2 km distance. Increasing accuracy and speed of wind parameters calculation signal processing technics have been studied in this research. Measurements results of IWL and continuous scanning lidar were compared. Also, IWL data processing modeling results have been analyzed.

Acceleration of integral imaging based incoherent Fourier hologram capture using graphic processing unit.

PubMed

Jeong, Kyeong-Min; Kim, Hee-Seung; Hong, Sung-In; Lee, Sung-Keun; Jo, Na-Young; Kim, Yong-Soo; Lim, Hong-Gi; Park, Jae-Hyeung

2012-10-08

Speed enhancement of integral imaging based incoherent Fourier hologram capture using a graphic processing unit is reported. Integral imaging based method enables exact hologram capture of real-existing three-dimensional objects under regular incoherent illumination. In our implementation, we apply parallel computation scheme using the graphic processing unit, accelerating the processing speed. Using enhanced speed of hologram capture, we also implement a pseudo real-time hologram capture and optical reconstruction system. The overall operation speed is measured to be 1 frame per second.

Single-chip microcomputer for image processing in the photonic measuring system

NASA Astrophysics Data System (ADS)

Smoleva, Olga S.; Ljul, Natalia Y.

2002-04-01

The non-contact measuring system has been designed for rail- track parameters control on the Moscow Metro. It detects some significant parameters: rail-track width, rail-track height, gage, rail-slums, crosslevel, pickets, and car speed. The system consists of three subsystems: non-contact system of rail-track width, height, and gage inspection, non-contact system of rail-slums inspection and subsystem for crosslevel, speed, and pickets detection. Data from subsystems is transferred to pre-processing unit. In order to process data received from subsystems, the single-chip signal processor ADSP-2185 must be used due to providing required processing speed. After data will be processed, it is send to PC, which processes it and outputs it in the readable form.

Workload Capacity: A Response Time-Based Measure of Automation Dependence.

PubMed

Yamani, Yusuke; McCarley, Jason S

2016-05-01

An experiment used the workload capacity measure C(t) to quantify the processing efficiency of human-automation teams and identify operators' automation usage strategies in a speeded decision task. Although response accuracy rates and related measures are often used to measure the influence of an automated decision aid on human performance, aids can also influence response speed. Mean response times (RTs), however, conflate the influence of the human operator and the automated aid on team performance and may mask changes in the operator's performance strategy under aided conditions. The present study used a measure of parallel processing efficiency, or workload capacity, derived from empirical RT distributions as a novel gauge of human-automation performance and automation dependence in a speeded task. Participants performed a speeded probabilistic decision task with and without the assistance of an automated aid. RT distributions were used to calculate two variants of a workload capacity measure, COR(t) and CAND(t). Capacity measures gave evidence that a diagnosis from the automated aid speeded human participants' responses, and that participants did not moderate their own decision times in anticipation of diagnoses from the aid. Workload capacity provides a sensitive and informative measure of human-automation performance and operators' automation dependence in speeded tasks. © 2016, Human Factors and Ergonomics Society.

Method for controlling gas metal arc welding

DOEpatents

Smartt, Herschel B.; Einerson, Carolyn J.; Watkins, Arthur D.

1989-01-01

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

Perception and Reality of Cognitive Function: Information Processing Speed, Perceived Memory Function, and Perceived Task Difficulty in Older Adults.

PubMed

Torrens-Burton, Anna; Basoudan, Nasreen; Bayer, Antony J; Tales, Andrea

2017-01-01

This study examines the relationships between two measures of information processing speed associated with executive function (Trail Making Test and a computer-based visual search test), the perceived difficulty of the tasks, and perceived memory function (measured by the Memory Functioning Questionnaire) in older adults (aged 50+ y) with normal general health, cognition (Montreal Cognitive Assessment score of 26+), and mood. The participants were recruited from the community rather than through clinical services, and none had ever sought or received help from a health professional for a memory complaint or mental health problem. For both the trail making and the visual search tests, mean information processing speed was not correlated significantly with perceived memory function. Some individuals did, however, reveal substantially slower information processing speeds (outliers) that may have clinical significance and indicate those who may benefit most from further assessment and follow up. For the trail making, but not the visual search task, higher levels of subjective memory dysfunction were associated with a greater perception of task difficulty. The relationship between actual information processing speed and perceived task difficulty also varied with respect to the task used. These findings highlight the importance of taking into account the type of task and metacognition factors when examining the integrity of information processing speed in older adults, particularly as this measure is now specifically cited as a key cognitive subdomain within the diagnostic framework for neurocognitive disorders.

Perception and Reality of Cognitive Function: Information Processing Speed, Perceived Memory Function, and Perceived Task Difficulty in Older Adults

PubMed Central

Torrens-Burton, Anna; Basoudan, Nasreen; Bayer, Antony J.; Tales, Andrea

2017-01-01

This study examines the relationships between two measures of information processing speed associated with executive function (Trail Making Test and a computer-based visual search test), the perceived difficulty of the tasks, and perceived memory function (measured by the Memory Functioning Questionnaire) in older adults (aged 50+ y) with normal general health, cognition (Montreal Cognitive Assessment score of 26+), and mood. The participants were recruited from the community rather than through clinical services, and none had ever sought or received help from a health professional for a memory complaint or mental health problem. For both the trail making and the visual search tests, mean information processing speed was not correlated significantly with perceived memory function. Some individuals did, however, reveal substantially slower information processing speeds (outliers) that may have clinical significance and indicate those who may benefit most from further assessment and follow up. For the trail making, but not the visual search task, higher levels of subjective memory dysfunction were associated with a greater perception of task difficulty. The relationship between actual information processing speed and perceived task difficulty also varied with respect to the task used. These findings highlight the importance of taking into account the type of task and metacognition factors when examining the integrity of information processing speed in older adults, particularly as this measure is now specifically cited as a key cognitive subdomain within the diagnostic framework for neurocognitive disorders. PMID:28984584

Cognition in older patients with multiple sclerosis compared to patients with amnestic mild cognitive impairment and healthy older adults.

PubMed

Roth, Alexandra K; Denney, Douglas R; Burns, Jeffrey M; Lynch, Sharon G

2018-06-25

Progress in the treatment of multiple sclerosis (MS) has resulted in larger numbers of patients living to an advanced age, but little is known about the cognitive status of these individuals. The primary purpose of this study was to identify differences in the cognitive performance between elderly individuals with MS and those with amnestic mild cognitive impairment (aMCI). Three groups ranging in age from 60 to 80 were compared: patients with MS (n = 64), patients with aMCI (n = 58), and healthy adults (n = 70). All participants completed a standard neuropsychological test battery that evaluated domains of attention, processing speed, executive function, memory, language, and visual spatial function. Compared to age- and gender-matched healthy controls, elderly MS patients exhibited a pattern of cognitive impairment centering on information processing speed and memory that was consistent with the deficits observed in other studies of MS patients regardless of age. Compared to aMCI patients, the MS patients exhibited worse performance on measures of processing speed, but better performance on a measure of memory under cued conditions (Selective Reminding Test), a nonspeeded measure of language (Boston Naming Test), and measures of executive function with processing speed statistically controlled (Trail Making Test, Stroop Test). Differences on neuropsychological measures can serve to distinguish aMCI from MS-related cognitive impairment in older patients, but it is essential that these measures control for the deficit in processing speed that is such a primary feature of MS. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Mapping the developmental constraints on working memory span performance.

PubMed

Bayliss, Donna M; Jarrold, Christopher; Baddeley, Alan D; Gunn, Deborah M; Leigh, Eleanor

2005-07-01

This study investigated the constraints underlying developmental improvements in complex working memory span performance among 120 children of between 6 and 10 years of age. Independent measures of processing efficiency, storage capacity, rehearsal speed, and basic speed of processing were assessed to determine their contribution to age-related variance in complex span. Results showed that developmental improvements in complex span were driven by 2 age-related but separable factors: 1 associated with general speed of processing and 1 associated with storage ability. In addition, there was an age-related contribution shared between working memory, processing speed, and storage ability that was important for higher level cognition. These results pose a challenge for models of complex span performance that emphasize the importance of processing speed alone.

Visual processing speed in old age.

PubMed

Habekost, Thomas; Vogel, Asmus; Rostrup, Egill; Bundesen, Claus; Kyllingsbaek, Søren; Garde, Ellen; Ryberg, Charlotte; Waldemar, Gunhild

2013-04-01

Mental speed is a common concept in theories of cognitive aging, but it is difficult to get measures of the speed of a particular psychological process that are not confounded by the speed of other processes. We used Bundesen's (1990) Theory of Visual Attention (TVA) to obtain specific estimates of processing speed in the visual system controlled for the influence of response latency and individual variations of the perception threshold. A total of 33 non-demented old people (69-87 years) were tested for the ability to recognize briefly presented letters. Performance was analyzed by the TVA model. Visual processing speed decreased approximately linearly with age and was on average halved from 70 to 85 years. Less dramatic aging effects were found for the perception threshold and the visual apprehension span. In the visual domain, cognitive aging seems to be most clearly related to reductions in processing speed. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

Level of recall, retrieval speed, and variability on the Cued-Recall Retrieval Speed Task (CRRST) in individuals with amnestic mild cognitive impairment.

PubMed

Ramratan, Wendy S; Rabin, Laura A; Wang, Cuiling; Zimmerman, Molly E; Katz, Mindy J; Lipton, Richard B; Buschke, Herman

2012-03-01

Individuals with amnestic mild cognitive impairment (aMCI) show deficits on traditional episodic memory tasks and reductions in speed of performance on reaction time tasks. We present results on a novel task, the Cued-Recall Retrieval Speed Task (CRRST), designed to simultaneously measure level and speed of retrieval. A total of 390 older adults (mean age, 80.2 years), learned 16 words based on corresponding categorical cues. In the retrieval phase, we measured accuracy (% correct) and retrieval speed/reaction time (RT; time from cue presentation to voice onset of a correct response) across 6 trials. Compared to healthy elderly adults (HEA, n = 303), those with aMCI (n = 87) exhibited poorer performance in retrieval speed (difference = -0.13; p < .0001) and accuracy on the first trial (difference = -0.19; p < .0001), and their rate of improvement in retrieval speed was slower over subsequent trials. Those with aMCI also had greater within-person variability in processing speed (variance ratio = 1.22; p = .0098) and greater between-person variability in accuracy (variance ratio = 2.08; p = .0001) relative to HEA. Results are discussed in relation to the possibility that computer-based measures of cued-learning and processing speed variability may facilitate early detection of dementia in at-risk older adults.

White matter and information processing speed following treatment with cranial-spinal radiation for pediatric brain tumor.

PubMed

Scantlebury, Nadia; Bouffet, Eric; Laughlin, Suzanne; Strother, Douglas; McConnell, Dina; Hukin, Juliette; Fryer, Christopher; Laperriere, Normand; Montour-Proulx, Isabelle; Keene, Daniel; Fleming, Adam; Jabado, Nada; Liu, Fang; Riggs, Lily; Law, Nicole; Mabbott, Donald J

2016-05-01

We compared the structure of specific white matter tracts and information processing speed between children treated for posterior fossa tumors with cranial-spinal radiation (n = 30), or with surgery +/- focal radiation (n = 29), and healthy children (n = 37). Probabilistic diffusion tensor imaging (DTI) tractography was used to delineate the inferior longitudinal fasciculi, optic radiation, inferior frontal occipital fasciculi, and uncinate fasciculi bilaterally. Information processing speed was measured using the coding and symbol search subtests of the Wechsler Intelligence Scales, and visual matching, pair cancellation, and rapid picture naming subtests of the Woodcock-Johnson Test of Cognitive Ability, 3rd revision. We examined group differences using repeated measures MANOVAs and path analyses were used to test the relations between treatment, white matter structure of the tracts, and information processing speed. DTI indices of the optic radiations, the inferior longitudinal fasciculi, and the inferior fronto-occipital fasciculi differed between children treated with cranial-spinal radiation and children treated with surgery +/- focal radiation, and healthy controls (p = .045). Children treated with cranial-spinal radiation also exhibited lower processing speed scores relative to healthy control subjects (p = .002). Notably, we observed that group differences in information processing speed were related to the structure of the right optic radiation (p = .002). We show that cranial-spinal radiation may have a negative impact on information processing speed via insult to the right optic radiations. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Between-person and within-person associations among processing speed, attention switching, and working memory in younger and older adults.

PubMed

Stawski, Robert S; Sliwinski, Martin J; Hofer, Scott M

2013-01-01

BACKGROUND/STUDY CONTEXT: Theories of cognitive aging predict associations among processes that transpire within individuals, but are often tested by examining between-person relationships. The authors provide an empirical demonstration of how associations among measures of processing speed, attention switching, and working memory are different when considered between persons versus within persons over time. A sample of 108 older adults (M (age) = 80.8, range = 66-95) and 68 younger adults (M (age) = 20.2, range = 18-24) completed measures of processing speed, attention switching, and working memory on six occasions over a 14-day period. Multilevel modeling was used to examine processing speed and attention switching performance as predictors of working memory performance simultaneously across days (within-person) and across individuals (between-person). The findings indicates that simple comparison and response speed predicted working memory better than attention switching between persons, whereas attention switching predicted working memory better than simple comparison and response speed within persons over time. Furthermore, the authors did not observe strong evidence of age differences in these associations either within or between persons. The findings of the current study suggest that processing speed is important for understanding between-person and age-related differences in working memory, whereas attention switching is more important for understanding within-person variation in working memory. The authors conclude that theories of cognitive aging should be evaluated by analysis of within-person processes, not exclusively age-related individual differences.

Between-Person and Within-Person Associations among Processing Speed, Attention Switching and Working Memory in Younger and Older Adults

PubMed Central

Stawski, Robert S.; Sliwinski, Martin J.; Hofer, Scott M.

2013-01-01

Background/Study Context Theories of cognitive aging predict associations among processes that transpire within individuals, but are often tested by examining between-person relationships. The authors provide an empirical demonstration of how associations among measures of processing speed, attention switching, and working memory are different when considered between persons versus within persons over time. Methods A sample of 108 older adults (Mage: 80.8, range: 66–95) and 68 younger adults (Mage: 20.2, range:18–24) completed measures of processing speed, attention switching, and working memory on six occasions over a 14-day period. Multilevel modeling was used to examine processing speed and attention switching performance as predictors of working memory performance simultaneously across days (within-person) and across individuals (between-person). Results The findings indicates that simple comparison and response speed predicted working memory better than attention switching between persons, whereas attention switching predicted working memory better than simple comparison and response speed within persons over time. Furthermore, the authors did not observe strong evidence of age differences in these associations either within or between persons. Conclusion The findings of the current study suggest that processing speed is important for understanding between-person and age-related differences in working memory, whereas attention switching is more important for understanding within-person variation in working memory. The authors conclude that theories of cognitive aging should be evaluated by analysis of within-person processes, not exclusively age-related individual differences. PMID:23421639

Predicting Word Reading and Comprehension with Executive Function and Speed Measures Across Development: A Latent Variable Analysis

PubMed Central

Christopher, Micaela E.; Miyake, Akira; Keenan, Janice M.; Pennington, Bruce; DeFries, John C.; Wadsworth, Sally J.; Willcutt, Erik; Olson, Richard K.

2012-01-01

The present study explored whether different executive control and speed measures (working memory, inhibition, processing speed, and naming speed) independently predict individual differences in word reading and reading comprehension. Although previous studies suggest these cognitive constructs are important for reading, we analyze the constructs simultaneously to test whether each is a unique predictor. We used latent variables from 483 participants (ages 8 to 16) to portion each cognitive and reading construct into its unique and shared variance. In these models we address two specific issues: (a) given that our wide age range may span the theoretical transition from “learning to read” to “reading to learn,” we first test whether the relation between word reading and reading comprehension is stable across two age groups (ages 8 to 10 and 11 to 16); and (b) the main theoretical question of interest: whether what is shared and what is separable for word reading and reading comprehension are associated with individual differences in working memory, inhibition, and measures of processing and naming speed. The results indicated that: (a) the relation between word reading and reading comprehension is largely invariant across the age groups; (b) working memory and general processing speed, but not inhibition or the speeded naming of non-alphanumeric stimuli, are unique predictors of both word reading and comprehension, with working memory equally important for both reading abilities and processing speed more important for word reading. These results have implications for understanding why reading comprehension and word reading are highly correlated yet separable. PMID:22352396

Contributions to Executive Dysfunction in Operation Enduring Freedom/Operation Iraqi Freedom Veterans With Posttraumatic Stress Disorder and History of Mild Traumatic Brain Injury.

PubMed

Jurick, Sarah M; Crocker, Laura D; Sanderson-Cimino, Mark; Keller, Amber V; Trenova, Liljana S; Boyd, Briana L; Twamley, Elizabeth W; Rodgers, Carie S; Schiehser, Dawn M; Aupperle, Robin L; Jak, Amy J

Posttraumatic stress disorder (PTSD), history of mild traumatic brain injury (mTBI), and executive function (EF) difficulties are prevalent in Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans. We evaluated the contributions of injury variables, lower-order cognitive component processes (processing speed/attention), and psychological symptoms to EF. OEF/OIF Veterans (N = 65) with PTSD and history of mTBI were administered neuropsychological tests of EF and self-report assessments of PTSD and depression. Those impaired on one or more EF measures had higher PTSD and depression symptoms and lower processing speed/attention performance than those with intact performance on all EF measures. Across participants, poorer attention/processing speed performance and higher psychological symptoms were associated with worse performance on specific aspects of EF (eg, inhibition and switching) even after accounting for injury variables. Although direct relationships between EF and injury variables were equivocal, there was an interaction between measures of injury burden and processing speed/attention such that those with greater injury burden exhibited significant and positive relationships between processing speed/attention and inhibition/switching, whereas those with lower injury burden did not. Psychological symptoms as well as lower-order component processes of EF (attention and processing speed) contribute significantly to executive dysfunction in OEF/OIF Veterans with PTSD and history of mTBI. However, there may be equivocal relationships between injury variables and EF that warrant further study. Results provide groundwork for more fully understanding cognitive symptoms in OEF/OIF Veterans with PTSD and history of mTBI that can inform psychological and cognitive interventions in this population.

Method for controlling gas metal arc welding

DOEpatents

Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

1987-08-10

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

Global Processing Speed in Children With Low Reading Ability and in Children and Adults With Typical Reading Ability: Exploratory Factor Analytic Models

PubMed Central

Peter, Beate; Matsushita, Mark; Raskind, Wendy H.

2013-01-01

Purpose To investigate processing speed as a latent dimension in children with dyslexia and children and adults with typical reading skills. Method Exploratory factor analysis (FA) was based on a sample of multigenerational families, each ascertained through a child with dyslexia. Eleven measures—6 of them timed—represented verbal and nonverbal processes, alphabet writing, and motor sequencing in the hand and oral motor system. FA was conducted in 4 cohorts (all children, a subset of children with low reading scores, a subset of children with typical reading scores, and adults with typical reading scores; total N = 829). Results Processing speed formed the first factor in all cohorts. Both measures of motor sequencing speed loaded on the speed factor with the other timed variables. Children with poor reading scores showed lower speed factor scores than did typical peers. The speed factor was negatively correlated with age in the adults. Conclusions The speed dimension was observed independently of participant cohort, gender, and reading ability. Results are consistent with a unified theory of processing speed as a quadratic function of age in typical development and with slowed processing in poor readers. PMID:21081672

Application of Multifunctional Doppler LIDAR for Noncontact Track Speed, Distance, and Curvature Assessment

NASA Astrophysics Data System (ADS)

Munoz, Joshua

The primary focus of this research is evaluation of feasibility, applicability, and accuracy of Doppler Light Detection And Ranging (LIDAR) sensors as non-contact means for measuring track speed, distance traveled, and curvature. Speed histories, currently measured with a rotary, wheelmounted encoder, serve a number of useful purposes, one significant use involving derailment investigations. Distance calculation provides a spatial reference system for operators to locate track sections of interest. Railroad curves, using an IMU to measure curvature, are monitored to maintain track infrastructure within regulations. Speed measured with high accuracy leads to highfidelity distance and curvature data through utilization of processor clock rate and left-and rightrail speed differentials during curve navigation, respectively. Wheel-mounted encoders, or tachometers, provide a relatively low-resolution speed profile, exhibit increased noise with increasing speed, and are subject to the inertial behavior of the rail car which affects output data. The IMU used to measure curvature is dependent on acceleration and yaw rate sensitivity and experiences difficulty in low-speed conditions. Preliminary system tests onboard a "Hy-Rail" utility vehicle capable of traveling on rail show speed capture is possible using the rails as the reference moving target and furthermore, obtaining speed profiles from both rails allows for the calculation of speed differentials in curves to estimate degrees curvature. Ground truth distance calibration and curve measurement were also carried out. Distance calibration involved placement of spatial landmarks detected by a sensor to synchronize distance measurements as a pre-processing procedure. Curvature ground truth measurements provided a reference system to confirm measurement results and observe alignment variation throughout a curve. Primary testing occurred onboard a track geometry rail car, measuring rail speed over substantial mileage in various weather conditions, providing highaccuracy data to further calculate distance and curvature along the test routes. Tests results indicate the LIDAR system measures speed at higher accuracy than the encoder, absent of noise influenced by increasing speed. Distance calculation is also high in accuracy, results showing high correlation with encoder and ground truth data. Finally, curvature calculation using speed data is shown to have good correlation with IMU measurements and a resolution capable of revealing localized track alignments. Further investigations involve a curve measurement algorithm and speed calibration method independent from external reference systems, namely encoder and ground truth data. The speed calibration results show a high correlation with speed data from the track geometry vehicle. It is recommended that the study be extended to provide assessment of the LIDAR's sensitivity to car body motion in order to better isolate the embedded behavior in the speed and curvature profiles. Furthermore, in the interest of progressing the system toward a commercially viable unit, methods for self-calibration and pre-processing to allow for fully independent operation is highly encouraged.

Level of Recall, Retrieval Speed, and Variability on the Cued-Recall Retrieval Speed Task (CRRST) in Individuals with Amnestic Mild Cognitive Impairment

PubMed Central

Ramratan, Wendy S.; Rabin, Laura A.; Wang, Cuiling; Zimmerman, Molly E.; Katz, Mindy J.; Lipton, Richard B.; Buschke, Herman

2013-01-01

Individuals with amnestic mild cognitive impairment (aMCI) show deficits on traditional episodic memory tasks and reductions in speed of performance on reaction time tasks. We present results on a novel task, the Cued-Recall Retrieval Speed Test (CRRST), designed to simultaneously measure level and speed of retrieval. 390 older adults (mean age of 80.2 years), learned 16 words based on corresponding categorical cues. In the retrieval phase, we measured accuracy (% correct) and retrieval speed/reaction time (RT; time from cue presentation to voice onset of a correct response) across 6 trials. Compared to healthy elderly adults (HEA, n = 303), those with aMCI (n = 87) exhibited poorer performance in retrieval speed (difference = −0.13, p<.0001) and accuracy on the first trial (difference = −0.19, p<.0001), and their rate of improvement in retrieval speed was slower over subsequent trials. Those with aMCI also had greater within-person variability in processing speed (variance ratio = 1.22, p = 0.0098) and greater between-person variability in accuracy (variance ratio = 2.08, p = 0.0001) relative to HEA. Results are discussed in relation to the possibility that computer-based measures of cued-learning and processing speed variability may facilitate early detection of dementia in at-risk older adults. PMID:22265423

An Examination of Mediators of the Transfer of Cognitive Speed of Processing Training to Everyday Functional Performance

PubMed Central

Edwards, Jerri D.; Ruva, Christine L.; O’Brien, Jennifer L.; Haley, Christine B.; Lister, Jennifer J.

2013-01-01

The purpose of these analyses was to examine mediators of the transfer of cognitive speed of processing training to improved everyday functional performance (Edwards, Wadley, Vance, Roenker, & Ball, 2005). Cognitive speed of processing and visual attention (as measured by the Useful Field of View Test; UFOV) were examined as mediators of training transfer. Secondary data analyses were conducted from the Staying Keen in Later Life (SKILL) study, a randomized cohort study including 126 community dwelling adults 63 to 87 years of age. In the SKILL study, participants were randomized to an active control group or cognitive speed of processing training (SOPT), a non-verbal, computerized intervention involving perceptual practice of visual tasks. Prior analyses found significant effects of training as measured by the UFOV and Timed Instrumental Activities of Daily Living (TIADL) Tests. Results from the present analyses indicate that speed of processing for a divided attention task significantly mediated the effect of SOPT on everyday performance (e.g., TIADL) in a multiple mediation model accounting for 91% of the variance. These findings suggest that everyday functional improvements found from SOPT are directly attributable to improved UFOV performance, speed of processing for divided attention in particular. Targeting divided attention in cognitive interventions may be important to positively affect everyday functioning among older adults. PMID:23066808

Writing Quality in Chinese Children: Speed and Fluency Matter

PubMed Central

Yan, Cathy Ming Wai; McBride-Chang, Catherine; Wagner, Richard K.; Zhang, Juan; Wong, Anita M. Y.; Shu, Hua

2015-01-01

There were two goals of the present study. The first was to create a scoring scheme by which 9-year-old Chinese children’s writing compositions could be rated to form a total score for writing quality. The second was to examine cognitive correlates of writing quality at age 9 from measures administered at ages 6–9. Age 9 writing compositions were scored using a 7-element rubric; following confirmatory factor analyses, 5 of these elements were retained to represent overall writing quality for subsequent analyses. Measures of vocabulary knowledge, Chinese word dictation, phonological awareness, speed of processing, speeded naming, and handwriting fluency at ages 6–9 were all significantly associated with the obtained overall writing quality measure even when the statistical effect of age was removed. With vocabulary knowledge, dictation skill, age, gender, and phonological awareness included in a regression equation, 35% of the variance in age 9 writing quality was explained. With the variables of speed of processing, speeded naming, and handwriting fluency additionally included as a block, 12% additional variance in the equation was explained. In addition to gender, overall unique correlates of writing quality were dictation, speed of processing, and handwriting fluency, underscoring the importance of both general automaticity and specific writing fluency for writing quality development in children. PMID:25750486

An examination of mediators of the transfer of cognitive speed of processing training to everyday functional performance.

PubMed

Edwards, Jerri D; Ruva, Christine L; O'Brien, Jennifer L; Haley, Christine B; Lister, Jennifer J

2013-06-01

The purpose of these analyses was to examine mediators of the transfer of cognitive speed of processing training to improved everyday functional performance (J. D. Edwards, V. G. Wadley,, D. E. Vance, D. L. Roenker, & K. K. Ball, 2005, The impact of speed of processing training on cognitive and everyday performance. Aging & Mental Health, 9, 262-271). Cognitive speed of processing and visual attention (as measured by the Useful Field of View Test; UFOV) were examined as mediators of training transfer. Secondary data analyses were conducted from the Staying Keen in Later Life (SKILL) study, a randomized cohort study including 126 community dwelling adults 63 to 87 years of age. In the SKILL study, participants were randomized to an active control group or cognitive speed of processing training (SOPT), a nonverbal, computerized intervention involving perceptual practice of visual tasks. Prior analyses found significant effects of training as measured by the UFOV and Timed Instrumental Activities of Daily Living (TIADL) Tests. Results from the present analyses indicate that speed of processing for a divided attention task significantly mediated the effect of SOPT on everyday performance (e.g., TIADL) in a multiple mediation model accounting for 91% of the variance. These findings suggest that everyday functional improvements found from SOPT are directly attributable to improved UFOV performance, speed of processing for divided attention in particular. Targeting divided attention in cognitive interventions may be important to positively affect everyday functioning among older adults. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Exploring Expressive Vocabulary Variability in Two-Year-Olds: The Role of Working Memory.

PubMed

Newbury, Jayne; Klee, Thomas; Stokes, Stephanie F; Moran, Catherine

2015-12-01

This study explored whether measures of working memory ability contribute to the wide variation in 2-year-olds' expressive vocabulary skills. Seventy-nine children (aged 24-30 months) were assessed by using standardized tests of vocabulary and visual cognition, a processing speed measure, and behavioral measures of verbal working memory and phonological short-term memory. Strong correlations were observed between phonological short-term memory, verbal working memory, and expressive vocabulary. Speed of spoken word recognition showed a moderate significant correlation with expressive vocabulary. In a multivariate regression model for expressive vocabulary, the most powerful predictor was a measure of phonological short-term memory (accounting for 66% unique variance), followed by verbal working memory (6%), sex (2%), and age (1%). Processing speed did not add significant unique variance. These findings confirm previous research positing a strong role for phonological short-term memory in early expressive vocabulary acquisition. They also extend previous research in two ways. First, a unique association between verbal working memory and expressive vocabulary in 2-year-olds was observed. Second, processing speed was not a unique predictor of variance in expressive vocabulary when included alongside measures of working memory.

Intraindividual Variability in Executive Functions but Not Speed of Processing or Conflict Resolution Predicts Performance Differences in Gait Speed in Older Adults

PubMed Central

Mahoney, Jeannette; Verghese, Joe

2014-01-01

Background. The relationship between executive functions (EF) and gait speed is well established. However, with the exception of dual tasking, the key components of EF that predict differences in gait performance have not been determined. Therefore, the current study was designed to determine whether processing speed, conflict resolution, and intraindividual variability in EF predicted variance in gait performance in single- and dual-task conditions. Methods. Participants were 234 nondemented older adults (mean age 76.48 years; 55% women) enrolled in a community-based cohort study. Gait speed was assessed using an instrumented walkway during single- and dual-task conditions. The flanker task was used to assess EF. Results. Results from the linear mixed effects model showed that (a) dual-task interference caused a significant dual-task cost in gait speed (estimate = 35.99; 95% CI = 33.19–38.80) and (b) of the cognitive predictors, only intraindividual variability was associated with gait speed (estimate = −.606; 95% CI = −1.11 to −.10). In unadjusted analyses, the three EF measures were related to gait speed in single- and dual-task conditions. However, in fully adjusted linear regression analysis, only intraindividual variability predicted performance differences in gait speed during dual tasking (B = −.901; 95% CI = −1.557 to −.245). Conclusion. Among the three EF measures assessed, intraindividual variability but not speed of processing or conflict resolution predicted performance differences in gait speed. PMID:24285744

High speed displacement measurement based on electro-magnetic induction applied to electromagnetically driven ring expansion

NASA Astrophysics Data System (ADS)

Han, Xiaotao; Wu, Jiawei; Huang, Lantao; Qiu, Lei; Chen, Qi; Cao, Quanliang; Herlach, Fritz; Li, Liang

2017-11-01

Investigating the mechanism of electromagnetic forming (EMF) becomes a hot topic in the field of metal forming. The high speed up to 200 m/s in EMF makes it a real challenge to capture the forming process. To this end, a new method for measuring displacement at high speed based on electromagnetic induction has been developed. Specifically this is used to measure the displacement of an expanding metal ring driven by a pulsed magnetic field; this is one of the basic EMF processes. The new method is simple and practical, and it combines high-speed response with adequate precision. The new measurement system consists of a printed circuit board (PCB) and a Rogowski probe. Eleven coaxial annular detecting probes are arranged in the PCB plate to acquire induced voltage at different positions, and a Rogowski probe is used to measure the current in the driving coil. The displacement of the ring is deduced by analyzing the output voltages of the detecting probes and the Rogowski probe. The feasibility of the method is verified by comparing the results with pictures from a high speed camera taken simultaneously.

Speed of perceptual grouping in acquired brain injury.

PubMed

Kurylo, Daniel D; Larkin, Gabriella Brick; Waxman, Richard; Bukhari, Farhan

2014-09-01

Evidence exists that damage to white matter connections may contribute to reduced speed of information processing in traumatic brain injury and stroke. Damage to such axonal projections suggests a particular vulnerability to functions requiring integration across cortical sites. To test this prediction, measurements were made of perceptual grouping, which requires integration of stimulus components. A group of traumatic brain injury and cerebral vascular accident patients and a group of age-matched healthy control subjects viewed arrays of dots and indicated the pattern into which stimuli were perceptually grouped. Psychophysical measurements were made of perceptual grouping as well as processing speed. The patient group showed elevated grouping thresholds as well as extended processing time. In addition, most patients showed progressive slowing of processing speed across levels of difficulty, suggesting reduced resources to accommodate increased demands on grouping. These results support the prediction that brain injury results in a particular vulnerability to functions requiring integration of information across the cortex, which may result from dysfunction of long-range axonal connection.

Executive functioning and processing speed in age-related differences in memory: contribution of a coding task.

PubMed

Baudouin, Alexia; Clarys, David; Vanneste, Sandrine; Isingrini, Michel

2009-12-01

The aim of the present study was to examine executive dysfunctioning and decreased processing speed as potential mediators of age-related differences in episodic memory. We compared the performances of young and elderly adults in a free-recall task. Participants were also given tests to measure executive functions and perceptual processing speed and a coding task (the Digit Symbol Substitution Test, DSST). More precisely, we tested the hypothesis that executive functions would mediate the age-related differences observed in the free-recall task better than perceptual speed. We also tested the assumption that a coding task, assumed to involve both executive processes and perceptual speed, would be the best mediator of age-related differences in memory. Findings first confirmed that the DSST combines executive processes and perceptual speed. Secondly, they showed that executive functions are a significant mediator of age-related differences in memory, and that DSST performance is the best predictor.

The role of auditory and cognitive factors in understanding speech in noise by normal-hearing older listeners

PubMed Central

Schoof, Tim; Rosen, Stuart

2014-01-01

Normal-hearing older adults often experience increased difficulties understanding speech in noise. In addition, they benefit less from amplitude fluctuations in the masker. These difficulties may be attributed to an age-related auditory temporal processing deficit. However, a decline in cognitive processing likely also plays an important role. This study examined the relative contribution of declines in both auditory and cognitive processing to the speech in noise performance in older adults. Participants included older (60–72 years) and younger (19–29 years) adults with normal hearing. Speech reception thresholds (SRTs) were measured for sentences in steady-state speech-shaped noise (SS), 10-Hz sinusoidally amplitude-modulated speech-shaped noise (AM), and two-talker babble. In addition, auditory temporal processing abilities were assessed by measuring thresholds for gap, amplitude-modulation, and frequency-modulation detection. Measures of processing speed, attention, working memory, Text Reception Threshold (a visual analog of the SRT), and reading ability were also obtained. Of primary interest was the extent to which the various measures correlate with listeners' abilities to perceive speech in noise. SRTs were significantly worse for older adults in the presence of two-talker babble but not SS and AM noise. In addition, older adults showed some cognitive processing declines (working memory and processing speed) although no declines in auditory temporal processing. However, working memory and processing speed did not correlate significantly with SRTs in babble. Despite declines in cognitive processing, normal-hearing older adults do not necessarily have problems understanding speech in noise as SRTs in SS and AM noise did not differ significantly between the two groups. Moreover, while older adults had higher SRTs in two-talker babble, this could not be explained by age-related cognitive declines in working memory or processing speed. PMID:25429266

A watershed model of individual differences in fluid intelligence.

PubMed

Kievit, Rogier A; Davis, Simon W; Griffiths, John; Correia, Marta M; Cam-Can; Henson, Richard N

2016-10-01

Fluid intelligence is a crucial cognitive ability that predicts key life outcomes across the lifespan. Strong empirical links exist between fluid intelligence and processing speed on the one hand, and white matter integrity and processing speed on the other. We propose a watershed model that integrates these three explanatory levels in a principled manner in a single statistical model, with processing speed and white matter figuring as intermediate endophenotypes. We fit this model in a large (N=555) adult lifespan cohort from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) using multiple measures of processing speed, white matter health and fluid intelligence. The model fit the data well, outperforming competing models and providing evidence for a many-to-one mapping between white matter integrity, processing speed and fluid intelligence. The model can be naturally extended to integrate other cognitive domains, endophenotypes and genotypes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Information processing speed as a mediator between psychosocial stress and global cognition in older adults.

PubMed

Foong, Hui F; Hamid, Tengku A; Ibrahim, Rahimah; Haron, Sharifah A

2018-01-01

The link between psychosocial stress and cognitive function is complex, and previous studies have indicated that it may be mediated by processing speed. Therefore, the main aim of this study was to examine whether processing speed mediates the association between psychosocial stress and global cognition in older adults. Moreover, the moderating role of gender in this model is examined as well. The study included 2322 community-dwelling older adults in Malaysia who were randomly selected through a multistage proportional cluster random sampling technique. Global cognition construct was measured by the Mini-Mental State Examination and Montreal Cognitive Assessment; psychosocial stress construct was measured by perceived stress, depression, loneliness, and neuroticism; and processing speed was assessed by the Digit Symbol Substitution Test. Structural equation modelling was used to analyze the mediation and moderation tests. Processing speed was found to partially mediate the relationship between psychosocial stress and global cognition (β in the direct model = -0.15, P < 0.001; β in the full mediation model = -0.11, P < 0.001). Moreover, the relationship between psychosocial stress and global cognition was found to be significant in men only, whereas the association between processing speed and global cognition was significant in men and women. Psychosocial stress may increase the likelihood that older adults will experience poor processing capacity, which could reduce their higher level cognition. Results indicate that there is a need to develop processing capacity intervention programmes for psychologically distressed older adults to prevent them from suffering cognitive decline. © 2018 Japanese Psychogeriatric Society.

Two speed factors of visual recognition independently correlated with fluid intelligence.

PubMed

Tachibana, Ryosuke; Namba, Yuri; Noguchi, Yasuki

2014-01-01

Growing evidence indicates a moderate but significant relationship between processing speed in visuo-cognitive tasks and general intelligence. On the other hand, findings from neuroscience proposed that the primate visual system consists of two major pathways, the ventral pathway for objects recognition and the dorsal pathway for spatial processing and attentive analysis. Previous studies seeking for visuo-cognitive factors of human intelligence indicated a significant correlation between fluid intelligence and the inspection time (IT), an index for a speed of object recognition performed in the ventral pathway. We thus presently examined a possibility that neural processing speed in the dorsal pathway also represented a factor of intelligence. Specifically, we used the mental rotation (MR) task, a popular psychometric measure for mental speed of spatial processing in the dorsal pathway. We found that the speed of MR was significantly correlated with intelligence scores, while it had no correlation with one's IT (recognition speed of visual objects). Our results support the new possibility that intelligence could be explained by two types of mental speed, one related to object recognition (IT) and another for manipulation of mental images (MR).

Preliminary exploration of the measurement of walking speed for the apoplectic people based on UHF RFID.

PubMed

Huang Hua-Lin; Mo Ling-Fei; Liu Ying-Jie; Li Cheng-Yang; Xu Qi-Meng; Wu Zhi-Tong

2015-08-01

The number of the apoplectic people is increasing while population aging is quickening its own pace. The precise measurement of walking speed is very important to the rehabilitation guidance of the apoplectic people. The precision of traditional measuring methods on speed such as stopwatch is relatively low, and high precision measurement instruments because of the high cost cannot be used widely. What's more, these methods have difficulty in measuring the walking speed of the apoplectic people accurately. UHF RFID tag has the advantages of small volume, low price, long reading distance etc, and as a wearable sensor, it is suitable to measure walking speed accurately for the apoplectic people. In order to measure the human walking speed, this paper uses four reader antennas with a certain distance to reads the signal strength of RFID tag. Because RFID tag has different RSSI (Received Signal Strength Indicator) in different distances away from the reader, researches on the changes of RSSI with time have been done by this paper to calculate walking speed. The verification results show that the precise measurement of walking speed can be realized by signal processing method with Gaussian Fitting-Kalman Filter. Depending on the variance of walking speed, doctors can predict the rehabilitation training result of the apoplectic people and give the appropriate rehabilitation guidance.

Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings

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

Hunt, A.; Easley, S.

2012-05-01

The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

Information processing speed and attention in multiple sclerosis: Reconsidering the Attention Network Test (ANT).

PubMed

Roth, Alexandra K; Denney, Douglas R; Lynch, Sharon G

2015-01-01

The Attention Network Test (ANT) assesses attention in terms of discrepancies between response times to items that differ in the burden they place on some facet of attention. However, simple arithmetic difference scores commonly used to capture these discrepancies fail to provide adequate control for information processing speed, leading to distorted findings when patient and control groups differ markedly in the speed with which they process and respond to stimulus information. This study examined attention networks in patients with multiple sclerosis (MS) using simple difference scores, proportional scores, and residualized scores that control for processing speed through statistical regression. Patients with relapsing-remitting (N = 20) or secondary progressive (N = 20) MS and healthy controls (N = 40) of similar age, education, and gender completed the ANT. Substantial differences between patients and controls were found on all measures of processing speed. Patients exhibited difficulties in the executive control network, but only when difference scores were considered. When deficits in information processing speed were adequately controlled using proportional or residualized score, deficits in the alerting network emerged. The effect sizes for these deficits were notably smaller than those for overall information processing speed and were also limited to patients with secondary progressive MS. Deficits in processing speed are more prominent in MS than those involving attention, and when the former are properly accounted for, differences in the latter are confined to the alerting network.

Neonatal Brain Pathology Predicts Adverse Attention and Processing Speed Outcomes in Very Preterm and/or Very Low Birth Weight Children

PubMed Central

Murray, Andrea L; Scratch, Shannon E; Thompson, Deanne K; Inder, Terrie E; Doyle, Lex W; Anderson, Jacqueline F. I.; Anderson, Peter J

2014-01-01

Objective This study aimed to examine attention and processing speed outcomes in very preterm (VPT; <32 weeks' gestational age) or very low birth weight (VLBW; <1500 g) children, and to assess the ability of brain abnormalities measured by neonatal magnetic resonance imaging (MRI) to predict outcome in these domains. Methods A cohort of 198 children born <30 weeks' gestational age and/or <1250 g and 70 term controls were examined. Neonatal MRI scans at term equivalent age were quantitatively assessed for white matter, cortical gray matter, deep gray matter, and cerebellar abnormalities. Attention and processing speed were assessed at 7 years using standardized neuropsychological tests. Group differences were tested in attention and processing speed, and the relationships between these cognitive domains and brain abnormalities at birth were investigated. Results At 7 years of age, the VPT/VLBW group performed significantly poorer than term controls on all attention and processing speed outcomes. Associations between adverse attention and processing speed performances at 7 years and higher neonatal brain abnormality scores were found; in particular, white matter and deep gray matter abnormalities were reasonable predictors of long-term cognitive outcomes. Conclusion Attention and processing speed are significant areas of concern in VPT/VLBW children. This is the first study to show that adverse attention and processing speed outcomes at 7 years are associated with neonatal brain pathology. PMID:24708047

Neonatal brain pathology predicts adverse attention and processing speed outcomes in very preterm and/or very low birth weight children.

PubMed

Murray, Andrea L; Scratch, Shannon E; Thompson, Deanne K; Inder, Terrie E; Doyle, Lex W; Anderson, Jacqueline F I; Anderson, Peter J

2014-07-01

This study aimed to examine attention and processing speed outcomes in very preterm (VPT; < 32 weeks' gestational age) or very low birth weight (VLBW; < 1,500 g) children, and to determine whether brain abnormality measured by neonatal MRI can be used to predict outcome in these domains. A cohort of 198 children born < 30 weeks' gestational age and/or < 1,250 g and 70 term controls were examined. Neonatal MRI scans at term equivalent age were quantitatively assessed for white matter, cortical gray matter, deep gray matter, and cerebellar abnormalities. Attention and processing speed were assessed at 7 years using standardized neuropsychological tests. Group differences were tested in attention and processing speed, and the relationships between these cognitive domains and brain abnormalities at birth were investigated. At 7 years of age, the VPT/VLBW group performed significantly poorer than term controls on all attention and processing speed outcomes. Associations between adverse attention and processing speed performances at 7 years and higher neonatal brain abnormality scores were found; in particular, white matter and deep gray matter abnormalities were reasonable predictors of long-term cognitive outcomes. Attention and processing speed are significant areas of concern in VPT/VLBW children. This is the first study to show that adverse attention and processing speed outcomes at 7 years are associated with neonatal brain pathology.

Intraindividual variability in executive functions but not speed of processing or conflict resolution predicts performance differences in gait speed in older adults.

PubMed

Holtzer, Roee; Mahoney, Jeannette; Verghese, Joe

2014-08-01

The relationship between executive functions (EF) and gait speed is well established. However, with the exception of dual tasking, the key components of EF that predict differences in gait performance have not been determined. Therefore, the current study was designed to determine whether processing speed, conflict resolution, and intraindividual variability in EF predicted variance in gait performance in single- and dual-task conditions. Participants were 234 nondemented older adults (mean age 76.48 years; 55% women) enrolled in a community-based cohort study. Gait speed was assessed using an instrumented walkway during single- and dual-task conditions. The flanker task was used to assess EF. Results from the linear mixed effects model showed that (a) dual-task interference caused a significant dual-task cost in gait speed (estimate = 35.99; 95% CI = 33.19-38.80) and (b) of the cognitive predictors, only intraindividual variability was associated with gait speed (estimate = -.606; 95% CI = -1.11 to -.10). In unadjusted analyses, the three EF measures were related to gait speed in single- and dual-task conditions. However, in fully adjusted linear regression analysis, only intraindividual variability predicted performance differences in gait speed during dual tasking (B = -.901; 95% CI = -1.557 to -.245). Among the three EF measures assessed, intraindividual variability but not speed of processing or conflict resolution predicted performance differences in gait speed. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Measures of digit span and verbal rehearsal speed in deaf children after more than 10 years of cochlear implantation.

PubMed

Pisoni, David B; Kronenberger, William G; Roman, Adrienne S; Geers, Ann E

2011-02-01

Conventional assessments of outcomes in deaf children with cochlear implants (CIs) have focused primarily on endpoint or product measures of speech and language. Little attention has been devoted to understanding the basic underlying core neurocognitive factors involved in the development and processing of speech and language. In this study, we examined the development of factors related to the quality of phonological information in immediate verbal memory, including immediate memory capacity and verbal rehearsal speed, in a sample of deaf children after >10 yrs of CI use and assessed the correlations between these two process measures and a set of speech and language outcomes. Of an initial sample of 180 prelingually deaf children with CIs assessed at ages 8 to 9 yrs after 3 to 7 yrs of CI use, 112 returned for testing again in adolescence after 10 more years of CI experience. In addition to completing a battery of conventional speech and language outcome measures, subjects were administered the Wechsler Intelligence Scale for Children-III Digit Span subtest to measure immediate verbal memory capacity. Sentence durations obtained from the McGarr speech intelligibility test were used as a measure of verbal rehearsal speed. Relative to norms for normal-hearing children, Digit Span scores were well below average for children with CIs at both elementary and high school ages. Improvement was observed over the 8-yr period in the mean longest digit span forward score but not in the mean longest digit span backward score. Longest digit span forward scores at ages 8 to 9 yrs were significantly correlated with all speech and language outcomes in adolescence, but backward digit spans correlated significantly only with measures of higher-order language functioning over that time period. While verbal rehearsal speed increased for almost all subjects between elementary grades and high school, it was still slower than the rehearsal speed obtained from a control group of normal-hearing adolescents. Verbal rehearsal speed at ages 8 to 9 yrs was also found to be strongly correlated with speech and language outcomes and Digit Span scores in adolescence. Despite improvement after 8 additional years of CI use, measures of immediate verbal memory capacity and verbal rehearsal speed, which reflect core fundamental information processing skills associated with representational efficiency and information processing capacity, continue to be delayed in children with CIs relative to NH peers. Furthermore, immediate verbal memory capacity and verbal rehearsal speed at 8 to 9 yrs of age were both found to predict speech and language outcomes in adolescence, demonstrating the important contribution of these processing measures for speech-language development in children with CIs. Understanding the relations between these core underlying processes and speech-language outcomes in children with CIs may help researchers to develop new approaches to intervention and treatment of deaf children who perform poorly with their CIs. Moreover, this knowledge could be used for early identification of deaf children who may be at high risk for poor speech and language outcomes after cochlear implantation as well as for the development of novel targeted interventions that focus selectively on these core elementary information processing variables.

Human Evoked Cortical Activity to Silent Gaps in Noise: Effects of Age, Attention, and Cortical Processing Speed

PubMed Central

Harris, Kelly C.; Wilson, Sara; Eckert, Mark A.; Dubno, Judy R.

2011-01-01

Objectives The goal of this study was to examine the degree to which age-related differences in early or automatic levels of auditory processing and attention-related processes explain age-related differences in auditory temporal processing. We hypothesized that age-related differences in attention and cognition compound age-related differences at automatic levels of processing, contributing to the robust age effects observed during challenging listening tasks. Design We examined age-related and individual differences in cortical event-related potential (ERP) amplitudes and latencies, processing speed, and gap detection from twenty-five younger and twenty-five older adults with normal hearing. ERPs were elicited by brief silent periods (gaps) in an otherwise continuous broadband noise and were measured under two listening conditions, passive and active. During passive listening, participants ignored the stimulus and read quietly. During active listening, participants button pressed each time they detected a gap. Gap detection (percent detected) was calculated for each gap duration during active listening (3, 6, 9, 12 and 15 ms). Processing speed was assessed using the Purdue Pegboard test and the Connections Test. Repeated measures ANOVAs assessed effects of age on gap detection, processing speed, and ERP amplitudes and latencies. An “attention modulation” construct was created using linear regression to examine the effects of attention while controlling for age-related differences in auditory processing. Pearson correlation analyses assessed the extent to which attention modulation, ERPs, and processing speed predicted behavioral gap detection. Results: Older adults had significantly poorer gap detection and slower processing speed than younger adults. Even after adjusting for poorer gap detection, the neurophysiological response to gap onset was atypical in older adults with reduced P2 amplitudes and virtually absent N2 responses. Moreover, individual differences in attention modulation of P2 response latencies and N2 amplitudes predicted gap detection and processing speed in older adults. That is, older adults with P2 latencies that decreased and N2 amplitudes that increased with active listening had faster processing speed and better gap detection than those older adults whose P2 latencies increased and N2 amplitudes decreased with attention Conclusions Results from the current study are broadly consistent with previous findings that older adults exhibit significantly poorer gap detection than younger adults in challenging tasks. Even after adjusting for poorer gap detection, older and younger adults showed robust differences in their electrophysiological responses to sound offset. Furthermore, the degree to which attention modulated the ERP was associated with individual variation in measures of processing speed and gap detection. Taken together, these results suggests an age-related deficit in early or automatic levels of auditory temporal processing and that some older adults may be less able to compensate for declines in processing by attending to the stimulus. These results extend our previous findings and support the hypothesis that age-related differences in cognitive or attention-related processing, including processing speed, contribute to an age-related decrease in gap detection. PMID:22374321

Role of processing speed and depressed mood on encoding, storage, and retrieval memory functions in patients diagnosed with schizophrenia.

PubMed

Brébion, Gildas; David, Anthony S; Bressan, Rodrigo A; Pilowsky, Lyn S

2007-01-01

The role of various types of slowing of processing speed, as well as the role of depressed mood, on each stage of verbal memory functioning in patients diagnosed with schizophrenia was investigated. Mixed lists of high- and low-frequency words were presented, and immediate and delayed free recall and recognition were required. Two levels of encoding were studied by contrasting the relatively automatic encoding of the high-frequency words and the more effortful encoding of the low-frequency words. Storage was studied by contrasting immediate and delayed recall. Retrieval was studied by contrasting free recall and recognition. Three tests of motor and cognitive processing speed were administered as well. Regression analyses involving the three processing speed measures revealed that cognitive speed was the only predictor of the recall and recognition of the low-frequency words. Furthermore, slowing in cognitive speed accounted for the deficit in recall and recognition of the low-frequency words relative to a healthy control group. Depressed mood was significantly associated with recognition of the low-frequency words. Neither processing speed nor depressed mood was associated with storage efficiency. It is concluded that both cognitive speed slowing and depressed mood impact on effortful encoding processes.

Speed of processing and strategic control of attention after traumatic brain injury.

PubMed

Dymowski, Alicia Rhian; Owens, Jacqueline Anne; Ponsford, Jennie Louise; Willmott, Catherine

2015-01-01

Slowed information processing speed has consistently been documented after traumatic brain injury (TBI). Debate continues as to whether deficits in strategic control are proportionate to, or remain after controlling for, reduced speed of processing. The study aim was to investigate the association of speed of processing and strategic control of attention with working memory, selective attention, response inhibition, and mental flexibility task performance after TBI using traditional and novel clinical measures. Twenty-five individuals with complicated mild to severe TBI (post-traumatic amnesia duration, M = 39.52 days, SD = 38.34; worst Glasgow Coma Scale score, M = 7.33, SD = 4.35; time post-injury, M = 392.64 days, SD = 537.19) and 25 matched healthy controls completed assessment of attentional and executive functioning. Measures included the Symbol Digit Modalities Test (SDMT), the computerized Selective Attention Task (SAT), the Ruff 2&7 Selective Attention Test (2&7), the visual n-back, Digit Span, Hayling Test, and Trail Making Test (TMT). t tests revealed that individuals with TBI demonstrated reduced processing speed on the SDMT, n-back, SAT, 2&7, Hayling Test, and TMT-A (p ≤ .002 for all). Digit Span performance did not differ between groups. Mixed-model ANOVAs revealed that individuals with TBI demonstrated a disproportionate increase in reaction time with complexity, which was accounted for by speed on the SAT but remained on the Hayling Inhibition Test after controlling for speed in ANCOVAs. Mann-Whitney U tests revealed that individuals with TBI also made more errors on the Hayling Test, missed responses on the n-back and were unable to benefit from the automatic condition of the 2&7. While slowed speed of information processing was pervasive across tasks after TBI, residual difficulties in response inhibition remained after controlling for slowness, which suggests impaired strategic control. These findings support targeted intervention for slowed speed of thinking and inhibition following TBI.

Testing for Neuropsychological Endophenotypes in Siblings Discordant for ADHD

PubMed Central

Bidwell, L. Cinnamon; Willcutt, Erik G.; DeFries, John C.; Pennington, Bruce F.

2007-01-01

Objective Neurocognitive deficits associated with attention deficit-hyperactivity disorder (ADHD) may be useful intermediate endophenotypes for determining specific genetic pathways that contribute to ADHD. Methods This study administered 17 measures from prominent neuropsychological theories of ADHD (executive function, processing speed, arousal regulation and motivation/delay aversion) in dizygotic (DZ) twin pairs discordant for ADHD and control twin pairs (ages 8–18) in order to compare performance between twins affected with ADHD (n = 266), their unaffected co-twins (n = 228), and control children from twin pairs without ADHD or learning difficulties (n = 332). Results ADHD subjects show significant impairment on executive function, processing speed, and response variability measures compared to control subjects. Unaffected cotwins of ADHD subjects are significantly impaired on nearly all the same measures as their ADHD siblings, even when subclinical symptoms of ADHD are controlled. Conclusion Executive function, processing speed, and response variability deficits may be useful endophenotypes for genetic studies of ADHD. PMID:17585884

Effect of Speed of Processing Training on Older Driver Screening Measures.

PubMed

Eramudugolla, Ranmalee; Kiely, Kim M; Chopra, Sidhant; Anstey, Kaarin J

2017-01-01

Objective: Computerized training for cognitive enhancement is of great public interest, however, there is inconsistent evidence for the transfer of training gains to every day activity. Several large trials have focused on speed of processing (SOP) training with some promising findings for long-term effects on daily activity, but no immediate transfer to other cognitive tests. Here, we examine the transfer of SOP training gains to cognitive measures that are known predictors of driving safety in older adults. Methods: Fifty-three adults aged 65-87 years who were current drivers participated in a two group non-randomized design with repeated measures and a no-contact matched control group. The Intervention group completed an average of 7.9 ( SD = 3.0) hours of self-administered online SOP training at home. Control group was matched on age, gender and test-re-test interval. Measures included the Useful Field of View (UFOV) test, a Hazard Perception test, choice reaction time (Cars RT), Trail Making Test B, a Maze test, visual motion threshold, as well as road craft and road knowledge tests. Results: Speed of processing training resulted in significant improvement in processing speed on the UFOV test relative to controls, with an average change of -45.8 ms ( SE = 14.5), and effect size of ω 2 = 0.21. Performance on the Maze test also improved, but significant slowing on the Hazard Perception test was observed after SOP training. Training effects on the UFOV task was associated with similar effects on the Cars RT, but not the Hazard Perception and Maze tests, suggesting transfer to some but not all driving related measures. There were no effects of training on any of the other measures examined. Conclusion: Speed of processing training effects on the UFOV task can be achieved with self-administered, online training at home, with some transfer to other cognitive tests. However, differential effects of training may be observed for tasks requiring goal-directed search strategies rather than diffuse attention.

A Measure of Inspection Time in 4-Year-Old Children: The Benny Bee IT Task

ERIC Educational Resources Information Center

Williams, Sarah E.; Turley, Christopher; Nettelbeck, Ted; Burns, Nicholas R.

2009-01-01

Inspection time (IT) measures speed of information processing without the confounding influence of motor speed. While IT has been found to relate to cognitive abilities in adults and older children, no measure of IT has been validated for use with children younger than 6 years. This study examined the validity of a new measure of IT for preschool…

Executive Functioning and Processing Speed in Age-Related Differences in Memory: Contribution of a Coding Task

ERIC Educational Resources Information Center

Baudouin, Alexia; Clarys, David; Vanneste, Sandrine; Isingrini, Michel

2009-01-01

The aim of the present study was to examine executive dysfunctioning and decreased processing speed as potential mediators of age-related differences in episodic memory. We compared the performances of young and elderly adults in a free-recall task. Participants were also given tests to measure executive functions and perceptual processing speed…

NBC Contamination Survivability, Large Item Exteriors

DTIC Science & Technology

1998-04-17

environment. Ability to control temperature , relative humidity (RH), and wind speed is required. The facility must be designed to ensure safe and...2.2 Instrumentation. Measuring Devices Permissible Error of Measurement Air temperature ±0.5°C Relative humidity (RH) ±5 % Wind speed ±0.1 rm/sec Still...process, excluding monitoring, should last no longer than 75 minutes. (3) The item surface temperature is 30’C and exterior wind speed is no greater

Do attentional capacities and processing speed mediate the effect of age on executive functioning?

PubMed

Gilsoul, Jessica; Simon, Jessica; Hogge, Michaël; Collette, Fabienne

2018-02-06

The executive processes are well known to decline with age, and similar data also exists for attentional capacities and processing speed. Therefore, we investigated whether these two last nonexecutive variables would mediate the effect of age on executive functions (inhibition, shifting, updating, and dual-task coordination). We administered a large battery of executive, attentional and processing speed tasks to 104 young and 71 older people, and we performed mediation analyses with variables showing a significant age effect. All executive and processing speed measures showed age-related effects while only the visual scanning task performance (selective attention) was explained by age when controlled for gender and educational level. Regarding mediation analyses, visual scanning partially mediated the age effect on updating while processing speed partially mediated the age effect on shifting, updating and dual-task coordination. In a more exploratory way, inhibition was also found to partially mediate the effect of age on the three other executive functions. Attention did not greatly influence executive functioning in aging while, in agreement with the literature, processing speed seems to be a major mediator of the age effect on these processes. Interestingly, the global pattern of results seems also to indicate an influence of inhibition but further studies are needed to confirm the role of that variable as a mediator and its relative importance by comparison with processing speed.

Test-Taking Speed: Predictors and Implications

ERIC Educational Resources Information Center

Lovett, Benjamin J.; Lewandowski, Lawrence J.; Potts, Heather E.

2017-01-01

Students often feel time pressure when taking tests, and students with disabilities are sometimes given extended time testing accommodations, but little research has been done on the factors that affect students' test-taking speed. In the present study, 253 students at two colleges completed measures of processing speed, reading fluency, and…

Episodic feeling-of-knowing accuracy and cued recall in the elderly: evidence for double dissociation involving executive functioning and processing speed.

PubMed

Perrotin, Audrey; Isingrini, Michel; Souchay, Céline; Clarys, David; Taconnat, Laurence

2006-05-01

This research investigated adult age differences in a metamemory monitoring task-episodic feeling-of-knowing (FOK) and in an episodic memory task-cued recall. Executive functioning and processing speed were examined as mediators of these age differences. Young and elderly adults were administered an episodic FOK task, a cued recall task, executive tests and speed tests. Age-related decline was observed on all the measures. Correlation analyses revealed a pattern of double dissociation which indicates a specific relationship between executive score and FOK accuracy, and between speed score and cued recall. When executive functioning and processing speed were evaluated concurrently on FOK and cued recall variables, hierarchical regression analyses showed that executive score was a better mediator of age-related variance in FOK, and that speed score was the better mediator of age-related variance in cued recall.

Full-frame, high-speed 3D shape and deformation measurements using stereo-digital image correlation and a single color high-speed camera

NASA Astrophysics Data System (ADS)

Yu, Liping; Pan, Bing

2017-08-01

Full-frame, high-speed 3D shape and deformation measurement using stereo-digital image correlation (stereo-DIC) technique and a single high-speed color camera is proposed. With the aid of a skillfully designed pseudo stereo-imaging apparatus, color images of a test object surface, composed of blue and red channel images from two different optical paths, are recorded by a high-speed color CMOS camera. The recorded color images can be separated into red and blue channel sub-images using a simple but effective color crosstalk correction method. These separated blue and red channel sub-images are processed by regular stereo-DIC method to retrieve full-field 3D shape and deformation on the test object surface. Compared with existing two-camera high-speed stereo-DIC or four-mirror-adapter-assisted singe-camera high-speed stereo-DIC, the proposed single-camera high-speed stereo-DIC technique offers prominent advantages of full-frame measurements using a single high-speed camera but without sacrificing its spatial resolution. Two real experiments, including shape measurement of a curved surface and vibration measurement of a Chinese double-side drum, demonstrated the effectiveness and accuracy of the proposed technique.

Individual Differences in the Speed of Facial Emotion Recognition Show Little Specificity but Are Strongly Related with General Mental Speed: Psychometric, Neural and Genetic Evidence

PubMed Central

Liu, Xinyang; Hildebrandt, Andrea; Recio, Guillermo; Sommer, Werner; Cai, Xinxia; Wilhelm, Oliver

2017-01-01

Facial identity and facial expression processing are crucial socio-emotional abilities but seem to show only limited psychometric uniqueness when the processing speed is considered in easy tasks. We applied a comprehensive measurement of processing speed and contrasted performance specificity in socio-emotional, social and non-social stimuli from an individual differences perspective. Performance in a multivariate task battery could be best modeled by a general speed factor and a first-order factor capturing some specific variance due to processing emotional facial expressions. We further tested equivalence of the relationships between speed factors and polymorphisms of dopamine and serotonin transporter genes. Results show that the speed factors are not only psychometrically equivalent but invariant in their relation with the Catechol-O-Methyl-Transferase (COMT) Val158Met polymorphism. However, the 5-HTTLPR/rs25531 serotonin polymorphism was related with the first-order factor of emotion perception speed, suggesting a specific genetic correlate of processing emotions. We further investigated the relationship between several components of event-related brain potentials with psychometric abilities, and tested emotion specific individual differences at the neurophysiological level. Results revealed swifter emotion perception abilities to go along with larger amplitudes of the P100 and the Early Posterior Negativity (EPN), when emotion processing was modeled on its own. However, after partialling out the shared variance of emotion perception speed with general processing speed-related abilities, brain-behavior relationships did not remain specific for emotion. Together, the present results suggest that speed abilities are strongly interrelated but show some specificity for emotion processing speed at the psychometric level. At both genetic and neurophysiological levels, emotion specificity depended on whether general cognition is taken into account or not. These findings keenly suggest that general speed abilities should be taken into account when the study of emotion recognition abilities is targeted in its specificity. PMID:28848411

Face Configuration Accuracy and Processing Speed among Adults with High-Functioning Autism Spectrum Disorders

ERIC Educational Resources Information Center

Faja, Susan; Webb, Sara Jane; Merkle, Kristen; Aylward, Elizabeth; Dawson, Geraldine

2009-01-01

The present study investigates the accuracy and speed of face processing employed by high-functioning adults with autism spectrum disorders (ASDs). Two behavioral experiments measured sensitivity to distances between features and face recognition when performance depended on holistic versus featural information. Results suggest adults with ASD…

Depressed Mood Mediates Decline in Cognitive Processing Speed in Caregivers

ERIC Educational Resources Information Center

Vitaliano, Peter P.; Zhang, Jianping; Young, Heather M.; Caswell, Lisa W.; Scanlan, James M.; Echeverria, Diana

2009-01-01

Purpose: Very few studies have examined cognitive decline in caregivers versus noncaregivers, and only 1 study has examined mediators of such decline. We evaluated the relationship between caregiver status and decline on the digit symbol test (DST; a measure of processing speed, attention, cognitive-motor translation, and visual scanning) and…

Processing Speed Measures as Clinical Markers for Children with Language Impairment

ERIC Educational Resources Information Center

Park, Jisook; Miller, Carol A.; Mainela-Arnold, Elina

2015-01-01

Purpose: This study investigated the relative utility of linguistic and nonlinguistic processing speed tasks as predictors of language impairment (LI) in children across 2 time points. Method: Linguistic and nonlinguistic reaction time data, obtained from 131 children (89 children with typical development [TD] and 42 children with LI; 74 boys and…

Two Speed Factors of Visual Recognition Independently Correlated with Fluid Intelligence

PubMed Central

Tachibana, Ryosuke; Namba, Yuri; Noguchi, Yasuki

2014-01-01

Growing evidence indicates a moderate but significant relationship between processing speed in visuo-cognitive tasks and general intelligence. On the other hand, findings from neuroscience proposed that the primate visual system consists of two major pathways, the ventral pathway for objects recognition and the dorsal pathway for spatial processing and attentive analysis. Previous studies seeking for visuo-cognitive factors of human intelligence indicated a significant correlation between fluid intelligence and the inspection time (IT), an index for a speed of object recognition performed in the ventral pathway. We thus presently examined a possibility that neural processing speed in the dorsal pathway also represented a factor of intelligence. Specifically, we used the mental rotation (MR) task, a popular psychometric measure for mental speed of spatial processing in the dorsal pathway. We found that the speed of MR was significantly correlated with intelligence scores, while it had no correlation with one’s IT (recognition speed of visual objects). Our results support the new possibility that intelligence could be explained by two types of mental speed, one related to object recognition (IT) and another for manipulation of mental images (MR). PMID:24825574

Measurements of Heavy Ion Differential Streaming with SOHO/CELIAS/CTOF and ACE/SWICS at 1 AU

NASA Astrophysics Data System (ADS)

Janitzek, Nils; Berger, Lars; Taut, Andreas; Drews, Christian; Wimmer-Schweingruber, Robert

2016-04-01

Helios measurements in the early 1980s showed the existence of a systematic velocity difference, called "differential streaming", between solar wind bulk protons and alpha particles with the alphas streaming faster than the protons. The absolute differential speed between these species decreases with radial distance to the Sun and decreasing proton speed. In the fast wind it was measured to be approximately half of the local Alfvén speed. However, the detailed processes of acceleration and regulation of differential streaming are still not well understood. A proposed key process is resonant wave particle interaction between the ions and Alfvén waves near the ion-cyclotron frequency which is able to accelerate the alphas preferentially due to their higher mass-per-charge ratio. Measuring the differential speed of a wide set of solar wind heavy ions and therefore extending the mass-per-charge range significantly can provide additional information on the underlying processes that we cannot infer from the alphas and protons alone. We analysed data measured at L1 by SOHO/CELIAS/CTOF in 1996 and ACE/SWICS from 2001 to 2010. Both instruments are linear time-of-flight mass spectrometers which measure the ions' radial 1D velocity distributions with a cadence of 5 and 12 minutes, respectively. Comparing the mean ion speed, with the mean proton speed measured routinely by the SOHO/CELIAS/MTOF/PM and ACE/SWEPAM, respectively, we obtain the differential streaming for major charge states of solar wind carbon, oxygen, neon, magnesium, silicon and iron. In the case of the SWICS data the magnetometer on-board ACE (ACE/MAG) allows us to directly relate the differential streaming to the ambient Alfvén velocity while the lack of in-situ magnetic field measurements on SOHO is compensated by a B-field extrapolation from the WIND spacecraft (WIND/MAG) to the SOHO site. Both instruments show a similar result: significant differential streaming between heavy ions and protons on the order of the local Alfvén speed for solar wind above 400 km/s. While for slow solar wind the picture is more complex, the differential streaming is ubiquitous in the fast wind. Neither of the instruments measured a clear trend with ion mass-per-charge as would be expected from simple models including ion cyclotron resonance as the main driving process. Finally, we discuss a possible dependence of the differential streaming on the solar cycle.

Measuring automatic retrieval: a comparison of implicit memory, process dissociation, and speeded response procedures.

PubMed

Horton, Keith D; Wilson, Daryl E; Vonk, Jennifer; Kirby, Sarah L; Nielsen, Tina

2005-07-01

Using the stem completion task, we compared estimates of automatic retrieval from an implicit memory task, the process dissociation procedure, and the speeded response procedure. Two standard manipulations were employed. In Experiment 1, a depth of processing effect was found on automatic retrieval using the speeded response procedure although this effect was substantially reduced in Experiment 2 when lexical processing was required of all words. In Experiment 3, the speeded response procedure showed an advantage of full versus divided attention at study on automatic retrieval. An implicit condition showed parallel effects in each study, suggesting that implicit stem completion may normally provide a good estimate of automatic retrieval. Also, we replicated earlier findings from the process dissociation procedure, but estimates of automatic retrieval from this procedure were consistently lower than those from the speeded response procedure, except when conscious retrieval was relatively low. We discuss several factors that may contribute to the conflicting outcomes, including the evidence for theoretical assumptions and criterial task differences between implicit and explicit tests.

Processing data, for improved, accuracy, from device for measuring speed of sound in a gas

DOEpatents

Owen, Thomas E.

2006-09-19

A method, used in connection with a pulse-echo type sensor for determining the speed of sound in a gas, for improving the accuracy of speed of sound measurements. The sensor operates on the principle that speed of sound can be derived from the difference between the two-way travel time of signals reflected from two different target faces of the sensor. This time difference is derived by computing the cross correlation between the two reflections. The cross correlation function may be fitted to a parabola whose vertex represents the optimum time coordinate of the coherence peak, thereby providing an accurate measure of the two-way time diffference.

Speed and Lateral Inhibition of Stimulus Processing Contribute to Individual Differences in Stroop-Task Performance.

PubMed

Naber, Marnix; Vedder, Anneke; Brown, Stephen B R E; Nieuwenhuis, Sander

2016-01-01

The Stroop task is a popular neuropsychological test that measures executive control. Strong Stroop interference is commonly interpreted in neuropsychology as a diagnostic marker of impairment in executive control, possibly reflecting executive dysfunction. However, popular models of the Stroop task indicate that several other aspects of color and word processing may also account for individual differences in the Stroop task, independent of executive control. Here we use new approaches to investigate the degree to which individual differences in Stroop interference correlate with the relative processing speed of word and color stimuli, and the lateral inhibition between visual stimuli. We conducted an electrophysiological and behavioral experiment to measure (1) how quickly an individual's brain processes words and colors presented in isolation (P3 latency), and (2) the strength of an individual's lateral inhibition between visual representations with a visual illusion. Both measures explained at least 40% of the variance in Stroop interference across individuals. As these measures were obtained in contexts not requiring any executive control, we conclude that the Stroop effect also measures an individual's pre-set way of processing visual features such as words and colors. This study highlights the important contributions of stimulus processing speed and lateral inhibition to individual differences in Stroop interference, and challenges the general view that the Stroop task primarily assesses executive control.

Information processing speed as a predictor of IQ in children with and without specific language impairment in grades 3 and 8.

PubMed

Park, Jisook; Mainela-Arnold, Elina; Miller, Carol A

2015-01-01

This study investigated (1) whether nonlinguistic processing speed predicts nonverbal IQ in TD children and children with SLI and (2) if the proposed relationship is different at two time points. The participants consisted of a subset of a longitudinal dataset, 55 typically developing children and 55 children with SLI. Children completed four nonverbal speed tasks and four subtests of the WISC-III. The WISC-III subtests requiring timed and untimed responses were examined separately. Linear mixed model analyses indicated that in both groups, processing speed predicted nonverbal IQ subtests that reward speedy responses, but not IQ subtests that do not. The relationships between processing speed and IQ with speed bonuses did not differ at grades 3 and 8, and these relationships also were not significantly different in children with SLI and their TD peers. The results suggest that the presence of processing speed limitations in many children with SLI raises questions about the utility of timed nonverbal IQ measures as tools for diagnosis of SLI. Future studies should investigate other cognitive assessments that could be used as inclusionary criteria for SLI. The reader will be able to (1) describe the relationship between processing speed and nonverbal IQ in children with TD and SLI and (2) discuss problems using an IQ criterion to diagnose children as having SLI. Copyright © 2014 Elsevier Inc. All rights reserved.

The Charging Process in a High-speed, Single-cylinder, Four-stroke Engine

NASA Technical Reports Server (NTRS)

Reynolds, Blake; Schecter, Harry; Taylor, E S

1939-01-01

Experimental measurements and theoretical calculations were made on an aircraft-type, single cylinder engine, in order to determine the physical nature of the inlet process, especially at high piston speeds. The engine was run at speeds from 1,500 to 2,600 r.p.m. (mean piston speeds of 1,370 to 2,380 feet per minute). Measurements were made of the cylinder pressure during the inlet stroke and of the power output and volumetric efficiency. Measurements were also made, with the engine not running, to determine the resistance and mass of air in the inlet valve port at various crank angles. Results of analysis indicate that mass has an appreciable effect, but friction plays the major part in restricting flow. The observed fact that the volumetric efficiency is considerably less than 100 percent is attributed to thermal effects. An estimate was made of the magnitude of these effects in the present case, and their general nature is discussed.

Evaluation and correction of laser-scanned point clouds

NASA Astrophysics Data System (ADS)

Teutsch, Christian; Isenberg, Tobias; Trostmann, Erik; Weber, Michael; Berndt, Dirk; Strothotte, Thomas

2005-01-01

The digitalization of real-world objects is of great importance in various application domains. E.g. in industrial processes quality assurance is very important. Geometric properties of workpieces have to be measured. Traditionally, this is done with gauges which is somewhat subjective and time-consuming. We developed a robust optical laser scanner for the digitalization of arbitrary objects, primary, industrial workpieces. As measuring principle we use triangulation with structured lighting and a multi-axis locomotor system. Measurements on the generated data leads to incorrect results if the contained error is too high. Therefore, processes for geometric inspection under non-laboratory conditions are needed that are robust in permanent use and provide high accuracy as well as high operation speed. The many existing methods for polygonal mesh optimization produce very esthetic 3D models but often require user interaction and are limited in processing speed and/or accuracy. Furthermore, operations on optimized meshes consider the entire model and pay only little attention to individual measurements. However, many measurements contribute to parts or single scans with possibly strong differences between neighboring scans being lost during mesh construction. Also, most algorithms consider unsorted point clouds although the scanned data is structured through device properties and measuring principles. We use this underlying structure to achieve high processing speeds and extract intrinsic system parameters and use them for fast pre-processing.

Intra-individual variability in information processing speed reflects white matter microstructure in multiple sclerosis.

PubMed

Mazerolle, Erin L; Wojtowicz, Magdalena A; Omisade, Antonina; Fisk, John D

2013-01-01

Slowed information processing speed is commonly reported in persons with multiple sclerosis (MS), and is typically investigated using clinical neuropsychological tests, which provide sensitive indices of mean-level information processing speed. However, recent studies have demonstrated that within-person variability or intra-individual variability (IIV) in information processing speed may be a more sensitive indicator of neurologic status than mean-level performance on clinical tests. We evaluated the neural basis of increased IIV in mildly affected relapsing-remitting MS patients by characterizing the relation between IIV (controlling for mean-level performance) and white matter integrity using diffusion tensor imaging (DTI). Twenty women with relapsing-remitting MS and 20 matched control participants completed the Computerized Test of Information Processing (CTIP), from which both mean response time and IIV were calculated. Other clinical measures of information processing speed were also collected. Relations between IIV on the CTIP and DTI metrics of white matter microstructure were evaluated using tract-based spatial statistics. We observed slower and more variable responses on the CTIP in MS patients relative to controls. Significant relations between white matter microstructure and IIV were observed for MS patients. Increased IIV was associated with reduced integrity in more white matter tracts than was slowed information processing speed as measured by either mean CTIP response time or other neuropsychological test scores. Thus, despite the common use of mean-level performance as an index of cognitive dysfunction in MS, IIV may be more sensitive to the overall burden of white matter disease at the microstructural level. Furthermore, our study highlights the potential value of considering within-person fluctuations, in addition to mean-level performance, for uncovering brain-behavior relationships in neurologic disorders with widespread white matter pathology.

Information processing efficiency in patients with multiple sclerosis.

PubMed

Archibald, C J; Fisk, J D

2000-10-01

Reduced information processing efficiency, consequent to impaired neural transmission, has been proposed as underlying various cognitive problems in patients with Multiple Sclerosis (MS). This study employed two measures developed from experimental psychology that control for the potential confound of perceptual-motor abnormalities (Salthouse, Babcock, & Shaw, 1991; Sternberg, 1966, 1969) to assess the speed of information processing and working memory capacity in patients with mild to moderate MS. Although patients had significantly more cognitive complaints than neurologically intact matched controls, their performance on standard tests of immediate memory span did not differ from control participants and their word list learning was within normal limits. On the experimental measures, both relapsing-remitting and secondary-progressive patients exhibited significantly slowed information processing speed relative to controls. However, only the secondary-progressive patients had an additional decrement in working memory capacity. Depression, fatigue, or neurologic disability did not account for performance differences on these measures. While speed of information processing may be slowed early in the disease process, deficits in working memory capacity may appear only as there is progression of MS. It is these latter deficits, however, that may underlie the impairment of new learning that patients with MS demonstrate.

Response Speed, Contingent Negative Variation and P300 in Alzheimer's Disease and MCI

ERIC Educational Resources Information Center

van Deursen, J. A.; Vuurman, E. F. P. M.; Smits, L. L.; Verhey, F. R. J.; Riedel, W. J.

2009-01-01

Background: Decreased speed of information processing is a hallmark of Alzheimer's disease (AD) and mild cognitive impairment (MCI). Recent studies suggest that response speed (RS) measures are very sensitive indicators of changes in longitudinal follow-up studies. Insight into the psycho-physiological underpinnings of slowed RS can be provided by…

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

Newsom, R. K.; Sivaraman, C.; Shippert, T. R.

Wind speed and direction, together with pressure, temperature, and relative humidity, are the most fundamental atmospheric state parameters. Accurate measurement of these parameters is crucial for numerical weather prediction. Vertically resolved wind measurements in the atmospheric boundary layer are particularly important for modeling pollutant and aerosol transport. Raw data from a scanning coherent Doppler lidar system can be processed to generate accurate height-resolved measurements of wind speed and direction in the atmospheric boundary layer.

Molecular-Based Optical Measurement Techniques for Transition and Turbulence in High-Speed Flow

NASA Technical Reports Server (NTRS)

Bathel, Brett F.; Danehy, Paul M.; Cutler, Andrew D.

2013-01-01

High-speed laminar-to-turbulent transition and turbulence affect the control of flight vehicles, the heat transfer rate to a flight vehicle's surface, the material selected to protect such vehicles from high heating loads, the ultimate weight of a flight vehicle due to the presence of thermal protection systems, the efficiency of fuel-air mixing processes in high-speed combustion applications, etc. Gaining a fundamental understanding of the physical mechanisms involved in the transition process will lead to the development of predictive capabilities that can identify transition location and its impact on parameters like surface heating. Currently, there is no general theory that can completely describe the transition-to-turbulence process. However, transition research has led to the identification of the predominant pathways by which this process occurs. For a truly physics-based model of transition to be developed, the individual stages in the paths leading to the onset of fully turbulent flow must be well understood. This requires that each pathway be computationally modeled and experimentally characterized and validated. This may also lead to the discovery of new physical pathways. This document is intended to describe molecular based measurement techniques that have been developed, addressing the needs of the high-speed transition-to-turbulence and high-speed turbulence research fields. In particular, we focus on techniques that have either been used to study high speed transition and turbulence or techniques that show promise for studying these flows. This review is not exhaustive. In addition to the probe-based techniques described in the previous paragraph, several other classes of measurement techniques that are, or could be, used to study high speed transition and turbulence are excluded from this manuscript. For example, surface measurement techniques such as pressure and temperature paint, phosphor thermography, skin friction measurements and photogrammetry (for model attitude and deformation measurement) are excluded to limit the scope of this report. Other physical probes such as heat flux gauges, total temperature probes are also excluded. We further exclude measurement techniques that require particle seeding though particle based methods may still be useful in many high speed flow applications. This manuscript details some of the more widely used molecular-based measurement techniques for studying transition and turbulence: laser-induced fluorescence (LIF), Rayleigh and Raman Scattering and coherent anti-Stokes Raman scattering (CARS). These techniques are emphasized, in part, because of the prior experience of the authors. Additional molecular based techniques are described, albeit in less detail. Where possible, an effort is made to compare the relative advantages and disadvantages of the various measurement techniques, although these comparisons can be subjective views of the authors. Finally, the manuscript concludes by evaluating the different measurement techniques in view of the precision requirements described in this chapter. Additional requirements and considerations are discussed to assist with choosing an optical measurement technique for a given application.

Developmental dyslexia and phonological processing in European Portuguese orthography.

PubMed

Moura, Octávio; Moreno, Joana; Pereira, Marcelino; Simões, Mário R

2015-02-01

This study analysed the performance of phonological processing, the diagnostic accuracy and the influence on reading in children who were native speakers of an orthography of intermediate depth. Portuguese children with developmental dyslexia (DD; N=24; aged 10-12 years), chronological age (CA)-matched controls (N=24; aged 10-12 years) and reading level (RL)-matched controls (N=24; aged 7-9 years) were tested on measures of phonological processing (phonological awareness, naming speed and verbal short-term memory) and reading. The results indicated that the children with DD performed significantly poorer in all measures compared with the CA and RL. Phonological awareness and naming speed showed a high accuracy (receiver operating characteristics curve analysis) for discriminating the children with DD from the CA and RL, whereas the presence of abnormally low scores in phonological awareness and naming speed was more frequent in the DD group than in the controls and the normative population. Hierarchical linear regression analyses revealed that phonological awareness was the most important predictor of all reading accuracy measures, whereas naming speed was particularly related to text reading fluency. Copyright © 2014 John Wiley & Sons, Ltd.

Decreased processing speed might account for working memory span deficit in schizophrenia, and might mediate the associations between working memory span and clinical symptoms.

PubMed

Brébion, G; Stephan-Otto, C; Huerta-Ramos, E; Usall, J; Perez Del Olmo, M; Contel, M; Haro, J M; Ochoa, S

2014-10-01

Verbal working memory span is decreased in patients with schizophrenia, and this might contribute to impairment in higher cognitive functions as well as to the formation of certain clinical symptoms. Processing speed has been identified as a crucial factor in cognitive efficiency in this population. We tested the hypothesis that decreased processing speed underlies the verbal working memory deficit in patients and mediates the associations between working memory span and clinical symptoms. Forty-nine schizophrenia inpatients recruited from units for chronic and acute patients, and forty-five healthy participants, were involved in the study. Verbal working memory span was assessed by means of the letter-number span. The Digit Copy test was used to assess motor speed, and the Digit Symbol Substitution Test to assess cognitive speed. The working memory span was significantly impaired in patients (F(1,90)=4.6, P<0.05). However, the group difference was eliminated when either the motor or the cognitive speed measure was controlled (F(1,89)=0.03, P=0.86, and F(1,89)=0.03, P=0.88). In the patient group, working memory span was significantly correlated with negative symptoms (r=-0.52, P<0.0001) and thought disorganisation (r=-0.34, P<0.025) scores. Regression analyses showed that the association with negative symptoms was no longer significant when the motor speed measure was controlled (β=-0.12, P=0.20), while the association with thought disorganisation was no longer significant when the cognitive speed measure was controlled (β=-0.10, P=0.26). Decrement in motor and cognitive speed plays a significant role in both the verbal working memory impairment observed in patients and the associations between verbal working memory impairment and clinical symptoms. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Interrelationships between Working Memory, Processing Speed, and Language Development in the Age Range 2-4 Years

ERIC Educational Resources Information Center

Newbury, Jayne; Klee, Thomas; Stokes, Stephanie F.; Moran, Catherine

2016-01-01

Purpose: This study explored associations between working memory and language in children aged 2-4 years. Method: Seventy-seven children aged 24-30 months were assessed on tests measuring language, visual cognition, verbal working memory (VWM), phonological short-term memory (PSTM), and processing speed. A standardized test of receptive and…

A fiber optic sensor for noncontact measurement of shaft speed, torque, and power

NASA Technical Reports Server (NTRS)

Madzsar, George C.

1990-01-01

A fiber optic sensor which enables noncontact measurement of the speed, torque and power of a rotating shaft was fabricated and tested. The sensor provides a direct measurement of shaft rotational speed and shaft angular twist, from which torque and power can be determined. Angles of twist between 0.005 and 10 degrees were measured. Sensor resolution is limited by the sampling rate of the analog to digital converter, while accuracy is dependent on the spot size of the focused beam on the shaft. Increasing the sampling rate improves measurement resolution, and decreasing the focused spot size increases accuracy. Digital processing allows for enhancement of an electronically or optically degraded signal.

A fiber optic sensor for noncontact measurement of shaft speed, torque and power

NASA Technical Reports Server (NTRS)

Madzsar, George C.

1990-01-01

A fiber optic sensor which enables noncontact measurement of the speed, torque and power of a rotating shaft was fabricated and tested. The sensor provides a direct measurement of shaft rotational speed and shaft angular twist, from which torque and power can be determined. Angles of twist between 0.005 and 10 degrees were measured. Sensor resolution is limited by the sampling rate of the analog to digital converter, while accuracy is dependent on the spot size of the focused beam on the shaft. Increasing the sampling rate improves measurement resolution, and decreasing the focused spot size increases accuracy. Digital processing allows for enhancement of an electronically or optically degraded signal.

Study on the high-frequency laser measurement of slot surface difference

NASA Astrophysics Data System (ADS)

Bing, Jia; Lv, Qiongying; Cao, Guohua

2017-10-01

In view of the measurement of the slot surface difference in the large-scale mechanical assembly process, Based on high frequency laser scanning technology and laser detection imaging principle, This paragraph designs a double galvanometer pulse laser scanning system. Laser probe scanning system architecture consists of three parts: laser ranging part, mechanical scanning part, data acquisition and processing part. The part of laser range uses high-frequency laser range finder to measure the distance information of the target shape and get a lot of point cloud data. Mechanical scanning part includes high-speed rotary table, high-speed transit and related structure design, in order to realize the whole system should be carried out in accordance with the design of scanning path on the target three-dimensional laser scanning. Data processing part mainly by FPGA hardware with LAbVIEW software to design a core, to process the point cloud data collected by the laser range finder at the high-speed and fitting calculation of point cloud data, to establish a three-dimensional model of the target, so laser scanning imaging is realized.

Differential relationships of somatic and cognitive anxiety with measures of processing speed in older adults.

PubMed

Schoen, Chelsea B; Holtzer, Roee

2017-09-01

Research suggests a reciprocal relationship between late-life anxiety and cognition, particularly attention and executive functions. Whereas evidence supports a conceptual distinction between cognitive and somatic dimensions of anxiety, their differential relationship with cognitive outcomes has not been examined, particularly on tests of attention/executive functions that rely on processing speed. Study goals were threefold: (a) to describe levels of overall, cognitive, and somatic anxiety in a sample of older adults without dementia, (b) to determine if overall anxiety is associated with performance on select measures of attention/executive functions that rely on processing speed, and (c) to determine if a differential relationship exists between cognitive and somatic anxiety and cognitive performance. Participants were 368 community-dwelling older adults. Results showed that elevated levels of somatic, but not cognitive anxiety were associated with poorer performance across measures. Findings suggest that the nature of anxiety symptoms may have important implications for cognitive performance in older adults.

Elucidation and visualization of solid-state transformation and mixing in a pharmaceutical mini hot melt extrusion process using in-line Raman spectroscopy.

PubMed

Van Renterghem, Jeroen; Kumar, Ashish; Vervaet, Chris; Remon, Jean Paul; Nopens, Ingmar; Vander Heyden, Yvan; De Beer, Thomas

2017-01-30

Mixing of raw materials (drug+polymer) in the investigated mini pharma melt extruder is achieved by using co-rotating conical twin screws and an internal recirculation channel. In-line Raman spectroscopy was implemented in the barrels, allowing monitoring of the melt during processing. The aim of this study was twofold: to investigate (I) the influence of key process parameters (screw speed - barrel temperature) upon the product solid-state transformation during processing of a sustained release formulation in recirculation mode; (II) the influence of process parameters (screw speed - barrel temperature - recirculation time) upon mixing of a crystalline drug (tracer) in an amorphous polymer carrier by means of residence time distribution (RTD) measurements. The results indicated a faster mixing endpoint with increasing screw speed. Processing a high drug load formulation above the drug melting temperature resulted in the production of amorphous drug whereas processing below the drug melting point produced solid dispersions with partially amorphous/crystalline drug. Furthermore, increasing the screw speed resulted in lower drug crystallinity of the solid dispersion. RTD measurements elucidated the improved mixing capacity when using the recirculation channel. In-line Raman spectroscopy has shown to be an adequate PAT-tool for product solid-state monitoring and elucidation of the mixing behavior during processing in a mini extruder. Copyright © 2016 Elsevier B.V. All rights reserved.

Cognitive aging on latent constructs for visual processing capacity: a novel structural equation modeling framework with causal assumptions based on a theory of visual attention.

PubMed

Nielsen, Simon; Wilms, L Inge

2014-01-01

We examined the effects of normal aging on visual cognition in a sample of 112 healthy adults aged 60-75. A testbattery was designed to capture high-level measures of visual working memory and low-level measures of visuospatial attention and memory. To answer questions of how cognitive aging affects specific aspects of visual processing capacity, we used confirmatory factor analyses in Structural Equation Modeling (SEM; Model 2), informed by functional structures that were modeled with path analyses in SEM (Model 1). The results show that aging effects were selective to measures of visual processing speed compared to visual short-term memory (VSTM) capacity (Model 2). These results are consistent with some studies reporting selective aging effects on processing speed, and inconsistent with other studies reporting aging effects on both processing speed and VSTM capacity. In the discussion we argue that this discrepancy may be mediated by differences in age ranges, and variables of demography. The study demonstrates that SEM is a sensitive method to detect cognitive aging effects even within a narrow age-range, and a useful approach to structure the relationships between measured variables, and the cognitive functional foundation they supposedly represent.

Cognitive ability at age 11 and 70 years, information processing speed, and APOE variation: the Lothian Birth Cohort 1936 study.

PubMed

Luciano, Michelle; Gow, Alan J; Harris, Sarah E; Hayward, Caroline; Allerhand, Mike; Starr, John M; Visscher, Peter M; Deary, Ian J

2009-03-01

The e4 allele of the apolipoprotein E (APOE) gene confers risk of Alzheimer's disease and, in some studies, relates to cognitive ability and decline in older people without Alzheimer's disease. Its relationship with processing speed, a contributor to cognitive decline with age, is largely unknown. This study tests the association of APOE with cognition and speed, with and without covarying childhood mental ability. The 1,013 participants were tested on cognitive ability at age 11 as part of the Scottish Mental Survey of 1947 and, at age 70, were tested on reasoning, working memory, information processing speed, and executive function. The results showed that APOE was associated with the general cognitive factor, 2 nonverbal tests, and choice reaction time (RT) variability; as expected, the e4 allele was the risk allele. RT measures and a general speed factor were nonlinearly related to APOE when factoring childhood ability (p < .05): The correlation between childhood ability and speed was lower in e4 allele carriers. APOE has an influence on nonverbal cognition in old age and interacts with childhood IQ to influence processing speed.

Real-time particle size analysis using focused beam reflectance measurement as a process analytical technology tool for a continuous granulation-drying-milling process.

PubMed

Kumar, Vijay; Taylor, Michael K; Mehrotra, Amit; Stagner, William C

2013-06-01

Focused beam reflectance measurement (FBRM) was used as a process analytical technology tool to perform inline real-time particle size analysis of a proprietary granulation manufactured using a continuous twin-screw granulation-drying-milling process. A significant relationship between D20, D50, and D80 length-weighted chord length and sieve particle size was observed with a p value of <0.0001 and R(2) of 0.886. A central composite response surface statistical design was used to evaluate the effect of granulator screw speed and Comil® impeller speed on the length-weighted chord length distribution (CLD) and particle size distribution (PSD) determined by FBRM and nested sieve analysis, respectively. The effect of granulator speed and mill speed on bulk density, tapped density, Compressibility Index, and Flowability Index were also investigated. An inline FBRM probe placed below the Comil-generated chord lengths and CLD data at designated times. The collection of the milled samples for sieve analysis and PSD evaluation were coordinated with the timing of the FBRM determinations. Both FBRM and sieve analysis resulted in similar bimodal distributions for all ten manufactured batches studied. Within the experimental space studied, the granulator screw speed (650-850 rpm) and Comil® impeller speed (1,000-2,000 rpm) did not have a significant effect on CLD, PSD, bulk density, tapped density, Compressibility Index, and Flowability Index (p value > 0.05).

Intermediate Cognitive Phenotypes in Bipolar Disorder

PubMed Central

Langenecker, Scott A.; Saunders, Erika F.H.; Kade, Allison M.; Ransom, Michael T.; McInnis, Melvin G.

2013-01-01

Background Intermediate cognitive phenotypes (ICPs) are measurable and quantifiable states that may be objectively assessed in a standardized method, and can be integrated into association studies, including genetic, biochemical, clinical, and imaging based correlates. The present study used neuropsychological measures as ICPs, with factor scores in executive functioning, attention, memory, fine motor function, and emotion processing, similar to prior work in schizophrenia. Methods Healthy control subjects (HC, n=34) and euthymic (E, n=66), depressed (D, n=43), or hypomanic/mixed (HM, n=13) patients with bipolar disorder (BD) were assessed with neuropsychological tests. These were from eight domains consistent with previous literature; auditory memory, visual memory, processing speed with interference resolution, verbal fluency and processing speed, conceptual reasoning and set-shifting, inhibitory control, emotion processing, and fine motor dexterity. Results Of the eight factor scores, the HC group outperformed the E group in three (Processing Speed with Interference Resolution, Visual Memory, Fine Motor Dexterity), the D group in seven (all except Inhibitory Control), and the HM group in four (Inhibitory Control, Processing Speed with Interference Resolution, Fine Motor Dexterity, and Auditory Memory). Limitations The HM group was relatively small, thus effects of this phase of illness may have been underestimated. Effects of medication could not be fully controlled without a randomized, double-blind, placebo-controlled study. Conclusions Use of the factor scores can assist in determining ICPs for BD and related disorders, and may provide more specific targets for development of new treatments. We highlight strong ICPs (Processing Speed with Interference Resolution, Visual Memory, Fine Motor Dexterity) for further study, consistent with the existing literature. PMID:19800130

Inertia Compensation While Scanning Screw Threads on Coordinate Measuring Machines

NASA Astrophysics Data System (ADS)

Kosarevsky, Sergey; Latypov, Viktor

2010-01-01

Usage of scanning coordinate-measuring machines for inspection of screw threads has become a common practice nowadays. Compared to touch trigger probing, scanning capabilities allow to speed up the measuring process while still maintaining high accuracy. However, in some cases accuracy drastically depends on the scanning speed. In this paper a compensation method is proposed allowing to reduce the influence of inertia of the probing system while scanning screw threads on coordinate-measuring machines.

Fast femtosecond laser ablation for efficient cutting of sintered alumina substrates

NASA Astrophysics Data System (ADS)

Oosterbeek, Reece N.; Ward, Thomas; Ashforth, Simon; Bodley, Owen; Rodda, Andrew E.; Simpson, M. Cather

2016-09-01

Fast, accurate cutting of technical ceramics is a significant technological challenge because of these materials' typical high mechanical strength and thermal resistance. Femtosecond pulsed lasers offer significant promise for meeting this challenge. Femtosecond pulses can machine nearly any material with small kerf and little to no collateral damage to the surrounding material. The main drawback to femtosecond laser machining of ceramics is slow processing speed. In this work we report on the improvement of femtosecond laser cutting of sintered alumina substrates through optimisation of laser processing parameters. The femtosecond laser ablation thresholds for sintered alumina were measured using the diagonal scan method. Incubation effects were found to fit a defect accumulation model, with Fth,1=6.0 J/cm2 (±0.3) and Fth,∞=2.5 J/cm2 (±0.2). The focal length and depth, laser power, number of passes, and material translation speed were optimised for ablation speed and high quality. Optimal conditions of 500 mW power, 100 mm focal length, 2000 μm/s material translation speed, with 14 passes, produced complete cutting of the alumina substrate at an overall processing speed of 143 μm/s - more than 4 times faster than the maximum reported overall processing speed previously achieved by Wang et al. [1]. This process significantly increases processing speeds of alumina substrates, thereby reducing costs, making femtosecond laser machining a more viable option for industrial users.

Information processing speed and 8-year mortality among community-dwelling elderly Japanese.

PubMed

Iwasa, Hajime; Kai, Ichiro; Yoshida, Yuko; Suzuki, Takao; Kim, Hunkyung; Yoshida, Hideyo

2014-01-01

Cognitive function is an important contributor to health among elderly adults. One reliable measure of cognitive functioning is information processing speed, which can predict incident dementia and is longitudinally related to the incidence of functional dependence. Few studies have examined the association between information processing speed and mortality. This 8-year prospective cohort study design with mortality surveillance examined the longitudinal relationship between information processing speed and all-cause mortality among community-dwelling elderly Japanese. A total of 440 men and 371 women aged 70 years or older participated in this study. The Digit Symbol Substitution Test (DSST) was used to assess information processing speed. DSST score was used as an independent variable, and age, sex, education level, depressive symptoms, chronic disease, sensory deficit, instrumental activities of daily living, walking speed, and cognitive impairment were used as covariates. During the follow-up period, 182 participants (133 men and 49 women) died. A multivariate Cox proportional hazards model showed that lower DSST score was associated with increased risk of mortality (hazard ratio [HR] = 1.62, 95% CI = 0.97-2.72; HR = 1.73, 95% CI = 1.05-2.87; and HR = 2.55, 95% CI = 1.51-4.29, for the third, second, and first quartiles of DSST score, respectively). Slower information processing speed was associated with shorter survival among elderly Japanese.

Dual N-Back Working Memory Training in Healthy Adults: A Randomized Comparison to Processing Speed Training

PubMed Central

Lawlor-Savage, Linette; Goghari, Vina M.

2016-01-01

Enhancing cognitive ability is an attractive concept, particularly for middle-aged adults interested in maintaining cognitive functioning and preventing age-related declines. Computerized working memory training has been investigated as a safe method of cognitive enhancement in younger and older adults, although few studies have considered the potential impact of working memory training on middle-aged adults. This study investigated dual n-back working memory training in healthy adults aged 30–60. Fifty-seven adults completed measures of working memory, processing speed, and fluid intelligence before and after a 5-week web-based dual n-back or active control (processing speed) training program. Results: Repeated measures multivariate analysis of variance failed to identify improvements across the three cognitive composites, working memory, processing speed, and fluid intelligence, after training. Follow-up Bayesian analyses supported null findings for training effects for each individual composite. Findings suggest that dual n-back working memory training may not benefit working memory or fluid intelligence in healthy adults. Further investigation is necessary to clarify if other forms of working memory training may be beneficial, and what factors impact training-related benefits, should they occur, in this population. PMID:27043141

Individual differences and predictors of forgetting in old age: the role of processing speed and working memory.

PubMed

Zimprich, Daniel; Kurtz, Tanja

2013-01-01

The goal of the present study was to examine whether individual differences in basic cognitive abilities, processing speed, and working memory, are reliable predictors of individual differences in forgetting rates in old age. The sample for the present study comprised 364 participants aged between 65 and 80 years from the Zurich Longitudinal Study on Cognitive Aging. The impact of basic cognitive abilities on forgetting was analyzed by modeling working memory and processing speed as predictors of the amount of forgetting of 27 words, which had been learned across five trials. Forgetting was measured over a 30-minute interval by using parceling and a latent change model, in which the latent difference between recall performance after five learning trials and a delayed recall was modeled. Results implied reliable individual differences in forgetting. These individual differences in forgetting were strongly related to processing speed and working memory. Moreover, an age-related effect, which was significantly stronger for forgetting than for learning, emerged even after controlling effects of processing speed and working memory.

A rough set-based measurement model study on high-speed railway safety operation.

PubMed

Hu, Qizhou; Tan, Minjia; Lu, Huapu; Zhu, Yun

2018-01-01

Aiming to solve the safety problems of high-speed railway operation and management, one new method is urgently needed to construct on the basis of the rough set theory and the uncertainty measurement theory. The method should carefully consider every factor of high-speed railway operation that realizes the measurement indexes of its safety operation. After analyzing the factors that influence high-speed railway safety operation in detail, a rough measurement model is finally constructed to describe the operation process. Based on the above considerations, this paper redistricts the safety influence factors of high-speed railway operation as 16 measurement indexes which include staff index, vehicle index, equipment index and environment. And the paper also provides another reasonable and effective theoretical method to solve the safety problems of multiple attribute measurement in high-speed railway operation. As while as analyzing the operation data of 10 pivotal railway lines in China, this paper respectively uses the rough set-based measurement model and value function model (one model for calculating the safety value) for calculating the operation safety value. The calculation result shows that the curve of safety value with the proposed method has smaller error and greater stability than the value function method's, which verifies the feasibility and effectiveness.

Processing speed in recurrent visual networks correlates with general intelligence.

PubMed

Jolij, Jacob; Huisman, Danielle; Scholte, Steven; Hamel, Ronald; Kemner, Chantal; Lamme, Victor A F

2007-01-08

Studies on the neural basis of general fluid intelligence strongly suggest that a smarter brain processes information faster. Different brain areas, however, are interconnected by both feedforward and feedback projections. Whether both types of connections or only one of the two types are faster in smarter brains remains unclear. Here we show, by measuring visual evoked potentials during a texture discrimination task, that general fluid intelligence shows a strong correlation with processing speed in recurrent visual networks, while there is no correlation with speed of feedforward connections. The hypothesis that a smarter brain runs faster may need to be refined: a smarter brain's feedback connections run faster.

High Speed Videometric Monitoring of Rock Breakage

NASA Astrophysics Data System (ADS)

Allemand, J.; Shortis, M. R.; Elmouttie, M. K.

2018-05-01

Estimation of rock breakage characteristics plays an important role in optimising various industrial and mining processes used for rock comminution. Although little research has been undertaken into 3D photogrammetric measurement of the progeny kinematics, there is promising potential to improve the efficacy of rock breakage characterisation. In this study, the observation of progeny kinematics was conducted using a high speed, stereo videometric system based on laboratory experiments with a drop weight impact testing system. By manually tracking individual progeny through the captured video sequences, observed progeny coordinates can be used to determine 3D trajectories and velocities, supporting the idea that high speed video can be used for rock breakage characterisation purposes. An analysis of the results showed that the high speed videometric system successfully observed progeny trajectories and showed clear projection of the progeny away from the impact location. Velocities of the progeny could also be determined based on the trajectories and the video frame rate. These results were obtained despite the limitations of the photogrammetric system and experiment processes observed in this study. Accordingly there is sufficient evidence to conclude that high speed videometric systems are capable of observing progeny kinematics from drop weight impact tests. With further optimisation of the systems and processes used, there is potential for improving the efficacy of rock breakage characterisation from measurements with high speed videometric systems.

Apathy, but not depression, is associated with executive dysfunction in cerebral small vessel disease

PubMed Central

Hollocks, Matthew J.; Morris, Robin G.; Markus, Hugh S.

2017-01-01

Objective To determine the prevalence of apathy and depression in cerebral small vessel disease (SVD), and the relationships between both apathy and depression with cognition. To examine whether apathy is specifically related to impairment in executive functioning and processing speed. Methods 196 patients with a clinical lacunar stroke and an anatomically corresponding lacunar infarct on MRI were compared to 300 stroke-free controls. Apathy and depression were measured using the Geriatric Depression Scale, and cognitive functioning was assessed using an SVD cognitive screening tool, the Brief Memory and Executive Test, which measures executive functioning/processing speed and memory/orientation. Path analysis and binary logistic regression were used to assess the relation between apathy, depression and cognitive impairment. Results 31 participants with SVD (15.8%) met criteria for apathy only, 23 (11.8%) for both apathy and depression, and 2 (1.0%) for depression only. In the SVD group the presence of apathy was related to global cognition, and specifically to impaired executive functioning/processing speed, but not memory/orientation. The presence of depression was not related to global cognition, impaired executive functioning/processing speed or memory/orientation. Conclusions Apathy is a common feature of SVD and is associated with impaired executive functioning/processing speed suggesting the two may share biological mechanisms. Screening for apathy should be considered in SVD, and further work is required to develop and evaluate effective apathy treatment or management in SVD. PMID:28493898

Moderating Effects of Cortisol on Neural-Cognitive Association in Cognitively Normal Elderly Subjects

PubMed Central

Lau, Way K. W.; Leung, Mei Kei; Law, Andrew C. K.; Lee, Tatia M. C.

2017-01-01

Cortisol homeostasis is important for healthy brain and cognitive aging. The aim of the current study is to investigate the role of serum cortisol levels in the relationship between regional brain volumes and cognitive processing speed in a group of cognitively normal elderly subjects. Forty-one healthy elderly participants were from a parallel longitudinal study. The reported data in this study reflects baseline measurements. Whole-brain anatomical scanning was performed using a 3.0 Tesla Philips Medical Systems Achieva scanner. Cognitive processing speed was assessed by the digit-symbol and symbol search tests, from the Chinese version of the Wechsler Adult Intelligence Scale—third edition (WAIS-III). Serum cortisol levels (sampled in the late morning) were measured by ELISA kits. Whole-brain regression analysis revealed that serum cortisol levels positively predicted the white matter volumes (WMV) of the right thalamus, the gray matter volumes (GMV) of the left thalamus and right cerebellar tonsil, and negatively predicted the WMV and GMV of the left middle temporal gyrus (MTG) in 41 healthy elderly participants. Furthermore, serum cortisol significantly moderated the relationship between the GMV of the left MTG and processing speed, as well as the GMV of the left thalamus and processing speed. This study provided the first piece of evidence supporting serum cortisol levels in moderating the relationship between regional brain volumes and processing speed in healthy elderly subjects. This observation enriches our understanding of the role of cortisol in brain morphology and cognitive functioning. PMID:28596732

Cognitive Risk Factors for Specific Learning Disorder: Processing Speed, Temporal Processing, and Working Memory.

PubMed

Moll, Kristina; Göbel, Silke M; Gooch, Debbie; Landerl, Karin; Snowling, Margaret J

2016-01-01

High comorbidity rates between reading disorder (RD) and mathematics disorder (MD) indicate that, although the cognitive core deficits underlying these disorders are distinct, additional domain-general risk factors might be shared between the disorders. Three domain-general cognitive abilities were investigated in children with RD and MD: processing speed, temporal processing, and working memory. Since attention problems frequently co-occur with learning disorders, the study examined whether these three factors, which are known to be associated with attention problems, account for the comorbidity between these disorders. The sample comprised 99 primary school children in four groups: children with RD, children with MD, children with both disorders (RD+MD), and typically developing children (TD controls). Measures of processing speed, temporal processing, and memory were analyzed in a series of ANCOVAs including attention ratings as covariate. All three risk factors were associated with poor attention. After controlling for attention, associations with RD and MD differed: Although deficits in verbal memory were associated with both RD and MD, reduced processing speed was related to RD, but not MD; and the association with RD was restricted to processing speed for familiar nameable symbols. In contrast, impairments in temporal processing and visuospatial memory were associated with MD, but not RD. © Hammill Institute on Disabilities 2014.

Non-Contact Measurement Using A Laser Scanning Probe

NASA Astrophysics Data System (ADS)

Modjarrad, Amir

1989-03-01

Traditional high accuracy touch-trigger probing can now be complemented by high speed, non-contact, profile scanning to give another "dimension" to the three-dimensional Co-ordinate Measuring Machines (CMMs). Some of the features of a specially developed laser scanning probe together with the trade-offs involved in the design of inspection systems that use triangulation are examined. Applications of such a laser probe on CMMs are numerous since high speed scanning allows inspection of many different components and surfaces. For example, car body panels, tyre moulds, aircraft wing skins, turbine blades, wax and clay models, plastics, etc. Other applications include in-process surveillance in manufacturing and food processing, robotics vision and many others. Some of these applications are discussed and practical examples, case studies and experimental results are given with particular reference to use on CMMs. In conclusion, future developments and market trends in high speed non-contact measurement are discussed.

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

A simple and reliable sensor for accurate measurement of angular speed for low speed rotating machinery

NASA Astrophysics Data System (ADS)

Kuosheng, Jiang; Guanghua, Xu; Tangfei, Tao; Lin, Liang; Yi, Wang; Sicong, Zhang; Ailing, Luo

2014-01-01

This paper presents the theory and implementation of a novel sensor system for measuring the angular speed (AS) of a shaft rotating at a very low speed range, nearly zero speed. The sensor system consists mainly of an eccentric sleeve rotating with the shaft on which the angular speed to be measured, and an eddy current displacement sensor to obtain the profile of the sleeve for AS calculation. When the shaft rotates at constant speed the profile will be a pure sinusoidal trace. However, the profile will be a phase modulated signal when the shaft speed is varied. By applying a demodulating procedure, the AS can be obtained in a straightforward manner. The sensor system was validated experimentally based on a gearbox test rig and the result shows that the AS obtained are consistent with that obtained by a conventional encoder. However, the new sensor gives very smooth and stable traces of the AS, demonstrating its higher accuracy and reliability in obtaining the AS of the low speed operations with speed-up and down transients. In addition, the experiment also shows that it is easy and cost-effective to be realised in different applications such as condition monitoring and process control.

Controlling the Temperature and Speed of the Phase Transition of VO 2 Microcrystals

DOE PAGES

Yoon, Joonseok; Kim, Howon; Chen, Xian; ...

2015-12-29

Here, we investigated the control of two important parameters of vanadium dioxide (VO 2 ) microcrystals, the phase transition temperature and speed, by varying microcrystal width. By using the reflectivity change between insulating and metallic phases, phase transition temperature is measured by optical microscopy. As the width of square cylinder-shaped microcrystals decreases from ~70 to ~1 μm, the phase transition temperature (67 °C for bulk) varied as much as 26.1 °C (19.7 °C) during heating (cooling). In addition, the propagation speed of phase boundary in the microcrystal, i.e., phase transition speed, is monitored at the onset of phase transition bymore » using the high-speed resistance measurement. The phase transition speed increases from 4.6 × 10 2 to 1.7 × 10 4 μm/s as the width decreases from ~50 to ~2 μm. While the statistical description for a heterogeneous nucleation process explains the size dependence on phase transition temperature of VO 2 , the increase of effective thermal exchange process is responsible for the enhancement of phase transition speed of small VO 2 microcrystals. These findings not only enhance the understanding of VO 2 intrinsic properties but also contribute to the development of innovative electronic devices.« less

Controlling the Temperature and Speed of the Phase Transition of VO 2 Microcrystals

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

Yoon, Joonseok; Kim, Howon; Chen, Xian

Here, we investigated the control of two important parameters of vanadium dioxide (VO 2 ) microcrystals, the phase transition temperature and speed, by varying microcrystal width. By using the reflectivity change between insulating and metallic phases, phase transition temperature is measured by optical microscopy. As the width of square cylinder-shaped microcrystals decreases from ~70 to ~1 μm, the phase transition temperature (67 °C for bulk) varied as much as 26.1 °C (19.7 °C) during heating (cooling). In addition, the propagation speed of phase boundary in the microcrystal, i.e., phase transition speed, is monitored at the onset of phase transition bymore » using the high-speed resistance measurement. The phase transition speed increases from 4.6 × 10 2 to 1.7 × 10 4 μm/s as the width decreases from ~50 to ~2 μm. While the statistical description for a heterogeneous nucleation process explains the size dependence on phase transition temperature of VO 2 , the increase of effective thermal exchange process is responsible for the enhancement of phase transition speed of small VO 2 microcrystals. These findings not only enhance the understanding of VO 2 intrinsic properties but also contribute to the development of innovative electronic devices.« less

Reading comprehension and working memory in learning-disabled readers: Is the phonological loop more important than the executive system?

PubMed

Swanson, H L

1999-01-01

This investigation explores the contribution of two working memory systems (the articulatory loop and the central executive) to the performance differences between learning-disabled (LD) and skilled readers. Performances of LD, chronological age (CA) matched, and reading level-matched children were compared on measures of phonological processing accuracy and speed (articulatory system), long-term memory (LTM) accuracy and speed, and executive processing. The results indicated that (a) LD readers were inferior on measures of articulatory, LTM, and executive processing; (b) LD readers were superior to RL readers on measures of executive processing, but were comparable to RL readers on measures of the articulatory and LTM system; (c) executive processing differences remained significant between LD and CA-matched children when measures of reading comprehension, articulatory processes, and LTM processes were partialed from the analysis; and (d) executive processing contributed significant variance to reading comprehension when measures of the articulatory and LTM systems were entered into a hierarchical regression model. In summary, LD readers experience constraints in the articulatory and LTM system, but constraints mediate only some of the influence of executive processing on reading comprehension. Further, LD readers suffer executive processing problems nonspecific to their reading comprehension problems. Copyright 1999 Academic Press.

Optimization of dynamic envelope measurement system for high speed train based on monocular vision

NASA Astrophysics Data System (ADS)

Wu, Bin; Liu, Changjie; Fu, Luhua; Wang, Zhong

2018-01-01

The definition of dynamic envelope curve is the maximum limit outline caused by various adverse effects during the running process of the train. It is an important base of making railway boundaries. At present, the measurement work of dynamic envelope curve of high-speed vehicle is mainly achieved by the way of binocular vision. There are some problems of the present measuring system like poor portability, complicated process and high cost. A new measurement system based on the monocular vision measurement theory and the analysis on the test environment is designed and the measurement system parameters, the calibration of camera with wide field of view, the calibration of the laser plane are designed and optimized in this paper. The accuracy has been verified to be up to 2mm by repeated tests and experimental data analysis. The feasibility and the adaptability of the measurement system is validated. There are some advantages of the system like lower cost, a simpler measurement and data processing process, more reliable data. And the system needs no matching algorithm.

Dynamic balancing of super-critical rotating structures using slow-speed data via parametric excitation

NASA Astrophysics Data System (ADS)

Tresser, Shachar; Dolev, Amit; Bucher, Izhak

2018-02-01

High-speed machinery is often designed to pass several "critical speeds", where vibration levels can be very high. To reduce vibrations, rotors usually undergo a mass balancing process, where the machine is rotated at its full speed range, during which the dynamic response near critical speeds can be measured. High sensitivity, which is required for a successful balancing process, is achieved near the critical speeds, where a single deflection mode shape becomes dominant, and is excited by the projection of the imbalance on it. The requirement to rotate the machine at high speeds is an obstacle in many cases, where it is impossible to perform measurements at high speeds, due to harsh conditions such as high temperatures and inaccessibility (e.g., jet engines). This paper proposes a novel balancing method of flexible rotors, which does not require the machine to be rotated at high speeds. With this method, the rotor is spun at low speeds, while subjecting it to a set of externally controlled forces. The external forces comprise a set of tuned, response dependent, parametric excitations, and nonlinear stiffness terms. The parametric excitation can isolate any desired mode, while keeping the response directly linked to the imbalance. A software controlled nonlinear stiffness term limits the response, hence preventing the rotor to become unstable. These forces warrant sufficient sensitivity required to detect the projection of the imbalance on any desired mode without rotating the machine at high speeds. Analytical, numerical and experimental results are shown to validate and demonstrate the method.

Tactical Approaches for Trading Science Objectives Against Measurements and Mission Design: Science Traceability Techniques at the Jet Propulsion Laboratory

NASA Astrophysics Data System (ADS)

Nash, A. E., III

2017-12-01

The most common approaches to identifying the most effective mission design to maximize science return from a potential set of competing alternative design approaches are often inefficient and inaccurate. Recently, Team-X at the Jet Propulsion Laboratory undertook an effort to improve both the speed and quality of science - measurement - mission design trade studies. We will report on the methodology & processes employed and their effectiveness in trade study speed and quality. Our results indicate that facilitated subject matter expert peers are the keys to speed and quality improvements in the effectiveness of science - measurement - mission design trade studies.

The effect of phasic auditory alerting on visual perception.

PubMed

Petersen, Anders; Petersen, Annemarie Hilkjær; Bundesen, Claus; Vangkilde, Signe; Habekost, Thomas

2017-08-01

Phasic alertness refers to a short-lived change in the preparatory state of the cognitive system following an alerting signal. In the present study, we examined the effect of phasic auditory alerting on distinct perceptual processes, unconfounded by motor components. We combined an alerting/no-alerting design with a pure accuracy-based single-letter recognition task. Computational modeling based on Bundesen's Theory of Visual Attention was used to examine the effect of phasic alertness on visual processing speed and threshold of conscious perception. Results show that phasic auditory alertness affects visual perception by increasing the visual processing speed and lowering the threshold of conscious perception (Experiment 1). By manipulating the intensity of the alerting cue, we further observed a positive relationship between alerting intensity and processing speed, which was not seen for the threshold of conscious perception (Experiment 2). This was replicated in a third experiment, in which pupil size was measured as a physiological marker of alertness. Results revealed that the increase in processing speed was accompanied by an increase in pupil size, substantiating the link between alertness and processing speed (Experiment 3). The implications of these results are discussed in relation to a newly developed mathematical model of the relationship between levels of alertness and the speed with which humans process visual information. Copyright © 2017 Elsevier B.V. All rights reserved.

In-process, non-destructive, dynamic testing of high-speed polymer composite rotors

NASA Astrophysics Data System (ADS)

Kuschmierz, Robert; Filippatos, Angelos; Günther, Philipp; Langkamp, Albert; Hufenbach, Werner; Czarske, Jürgen; Fischer, Andreas

2015-03-01

Polymer composite rotors are lightweight and offer great perspectives in high-speed applications such as turbo machinery. Currently, novel rotor structures and materials are investigated for the purpose of increasing machine efficiency and lifetime, as well as allowing for higher dynamic loads. However, due to the complexity of the composite materials an in-process measurement system is required. This allows for monitoring the evolution of damages under dynamic loads, for testing and predicting the structural integrity of composite rotors in process. In rotor design, it can be used for calibrating and improving models, simulating the dynamic behaviour of polymer composite rotors. The measurement system is to work non-invasive, offer micron uncertainty, as well as a high measurement rate of several tens of kHz. Furthermore, it must be applicable at high surface speeds and under technical vacuum. In order to fulfil these demands a novel laser distance measurement system was developed. It provides the angle resolved measurement of the biaxial deformation of a fibre-reinforced polymer composite rotor with micron uncertainty at surface speeds of more than 300 m/s. Furthermore, a simulation procedure combining a finite element model and a damage mechanics model is applied. A comparison of the measured data and the numerically calculated data is performed to validate the simulation towards rotor expansion. This validating procedure can be used for a model calibration in the future. The simulation procedure could be used to investigate different damage-test cases of the rotor, in order to define its structural behaviour without further experiments.

Executive deficits, not processing speed relates to abnormalities in distinct prefrontal tracts in amyotrophic lateral sclerosis.

PubMed

Pettit, Lewis D; Bastin, Mark E; Smith, Colin; Bak, Thomas H; Gillingwater, Thomas H; Abrahams, Sharon

2013-11-01

Cognitive impairment in amyotrophic lateral sclerosis is characterized by deficits on tests of executive function; however, the contribution of abnormal processing speed is unknown. Methods are confounded by tasks that depend on motor speed in patients with physical disability. Structural and functional magnetic resonance imaging studies have revealed multi-system cerebral involvement, with evidence of reduced white matter volume and integrity in predominant frontotemporal regions. The current study has two aims. First, to investigate whether cognitive impairments in amyotrophic lateral sclerosis are due to executive dysfunction or slowed processing speed using methodology that accommodates motor disability. This is achieved using a dual-task paradigm and tasks that manipulate stimulus presentation times and do not rely on response motor speed. Second, to identify relationships between specific cognitive impairments and the integrity of distinct white matter tracts. Thirty patients with amyotrophic lateral sclerosis and 30 age- and education-matched control subjects were administered an experimental dual-task procedure that combined a visual inspection time task and digit recall. In addition, measures of executive function (including letter fluency) and processing speed (visual inspection time and rapid serial letter identification) were administered. Integrity of white matter tracts was determined using region of interest analyses of diffusion tensor magnetic resonance imaging data. Patients with amyotrophic lateral sclerosis did not show impairments on tests of processing speed, but executive deficits were revealed once visual inspection time was combined with digit recall (dual-task) and in letter fluency. In addition to the corticospinal tracts, significant differences in fractional anisotropy and mean diffusivity were found between groups in a number of prefrontal and temporal white matter tracts including the anterior cingulate, anterior thalamic radiation, uncinate fasciculus and hippocampal portion of the cingulum bundles. Significant differences also emerged in the anterior corona radiata as well as in white matter underlying the superior, medial and inferior frontal gyri and the temporal gyri. Dual-task performance significantly correlated with fractional anisotropy measures in the middle frontal gyrus white matter and anterior corona radiata. Letter fluency indices significantly correlated with fractional anisotropy measures of the inferior frontal gyrus white matter and corpus callosum in addition to the corticospinal tracts and mean diffusivity measures in the white matter of the superior frontal gyrus. The current study demonstrates that cognitive impairment in amyotrophic lateral sclerosis is not due to generic slowing of processing speed. Moreover, different executive deficits are related to distinct prefrontal tract involvement in amyotrophic lateral sclerosis with dual-task impairment associating with dorsolateral prefrontal dysfunction and letter fluency showing greater dependence on inferolateral prefrontal dysfunction.

Global Processing Speed in Children with Low Reading Ability and in Children and Adults with Typical Reading Ability: Exploratory Factor Analytic Models

ERIC Educational Resources Information Center

Peter, Beate; Matsushita, Mark; Raskind, Wendy H.

2011-01-01

Purpose: To investigate processing speed as a latent dimension in children with dyslexia and children and adults with typical reading skills. Method: Exploratory factor analysis (FA) was based on a sample of multigenerational families, each ascertained through a child with dyslexia. Eleven measures--6 of them timed--represented verbal and…

Study into penetration speed during laser cutting of brain tissues.

PubMed

Yilbas, Z; Sami, M; Patiroglu, T

1998-01-01

The applications of CO2 continuous-wave lasers in neurosurgery have become important in recent years. Theoretical considerations of laser applicability in medicine are subsequently confirmed experimentally. To obtain precision operation in the laser cutting process, further theoretical developments and experimental studies need to be conducted. Consequently, in the present study, the heat transfer mechanism taking place during laser-tissue interaction is introduced using Fourier theory. The results obtained from the theoretical model are compared with the experimental results. In connection with this, an experiment is designed to measure the penetration speed during the laser cutting process. The measurement is carried out using an optical method. It is found that both results for the penetration speed obtained from the theory and experiment are in a good agreement.

Decomposing ADHD-Related Effects in Response Speed and Variability

PubMed Central

Karalunas, Sarah L.; Huang-Pollock, Cynthia L.; Nigg, Joel T.

2012-01-01

Objective Slow and variable reaction times (RTs) on fast tasks are such a prominent feature of Attention Deficit Hyperactivity Disorder (ADHD) that any theory must account for them. However, this has proven difficult because the cognitive mechanisms responsible for this effect remain unexplained. Although speed and variability are typically correlated, it is unclear whether single or multiple mechanisms are responsible for group differences in each. RTs are a result of several semi-independent processes, including stimulus encoding, rate of information processing, speed-accuracy trade-offs, and motor response, which have not been previously well characterized. Method A diffusion model was applied to RTs from a forced-choice RT paradigm in two large, independent case-control samples (NCohort 1= 214 and N Cohort 2=172). The decomposition measured three validated parameters that account for the full RT distribution, and assessed reproducibility of ADHD effects. Results In both samples, group differences in traditional RT variables were explained by slow information processing speed, and unrelated to speed-accuracy trade-offs or non-decisional processes (e.g. encoding, motor response). Conclusions RT speed and variability in ADHD may be explained by a single information processing parameter, potentially simplifying explanations that assume different mechanisms are required to account for group differences in the mean and variability of RTs. PMID:23106115

Automatic detection of health changes using statistical process control techniques on measured transfer times of elderly.

PubMed

Baldewijns, Greet; Luca, Stijn; Nagels, William; Vanrumste, Bart; Croonenborghs, Tom

2015-01-01

It has been shown that gait speed and transfer times are good measures of functional ability in elderly. However, data currently acquired by systems that measure either gait speed or transfer times in the homes of elderly people require manual reviewing by healthcare workers. This reviewing process is time-consuming. To alleviate this burden, this paper proposes the use of statistical process control methods to automatically detect both positive and negative changes in transfer times. Three SPC techniques: tabular CUSUM, standardized CUSUM and EWMA, known for their ability to detect small shifts in the data, are evaluated on simulated transfer times. This analysis shows that EWMA is the best-suited method with a detection accuracy of 82% and an average detection time of 9.64 days.

Visual processing speed.

PubMed

Owsley, Cynthia

2013-09-20

Older adults commonly report difficulties in visual tasks of everyday living that involve visual clutter, secondary task demands, and time sensitive responses. These difficulties often cannot be attributed to visual sensory impairment. Techniques for measuring visual processing speed under divided attention conditions and among visual distractors have been developed and have established construct validity in that those older adults performing poorly in these tests are more likely to exhibit daily visual task performance problems. Research suggests that computer-based training exercises can increase visual processing speed in older adults and that these gains transfer to enhancement of health and functioning and a slowing in functional and health decline as people grow older. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Influence of Selected Parameters on Evaluation of the Geometrical Shape Deviation - Cylindricity in 3D Measuring Machine Workspace

NASA Astrophysics Data System (ADS)

Drbúl, Mário; Šajgalík, Michal; Litvaj, lvan; Babík, Ondrej

2016-12-01

Each part as a final product and its surface is composed of various geometric elements, although at first glance seem as smooth and shiny. During the manufacturing process, there is a number of influences (e.g. selected manufacturing technology, production process, human factors, the strategy of measurement, scanning speed, shape of the measurement contact tip, temperature, or the surface tension and the like), which hinder the production of component with ideally shaped elements. From the economic and design point of view (in accordance with determined GPS standards), there is necessary fast and accurate analyze and evaluate these elements. Presented article deals with the influence of scanning speed and measuring strategy for assessment of shape deviations.

Note: High-speed Z tip scanner with screw cantilever holding mechanism for atomic-resolution atomic force microscopy in liquid

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

Reza Akrami, Seyed Mohammad; Miyata, Kazuki; Asakawa, Hitoshi

High-speed atomic force microscopy has attracted much attention due to its unique capability of visualizing nanoscale dynamic processes at a solid/liquid interface. However, its usability and resolution have yet to be improved. As one of the solutions for this issue, here we present a design of a high-speed Z-tip scanner with screw holding mechanism. We perform detailed comparison between designs with different actuator size and screw arrangement by finite element analysis. Based on the design giving the best performance, we have developed a Z tip scanner and measured its performance. The measured frequency response of the scanner shows a flatmore » response up to ∼10 kHz. This high frequency response allows us to achieve wideband tip-sample distance regulation. We demonstrate the applicability of the scanner to high-speed atomic-resolution imaging by visualizing atomic-scale calcite crystal dissolution process in water at 2 s/frame.« less

In-process, non-destructive multimodal dynamic testing of high-speed composite rotors

NASA Astrophysics Data System (ADS)

Kuschmierz, Robert; Filippatos, Angelos; Langkamp, Albert; Hufenbach, Werner; Czarske, Jürgern W.; Fischer, Andreas

2014-03-01

Fibre reinforced plastic (FRP) rotors are lightweight and offer great perspectives in high-speed applications such as turbo machinery. Currently, novel rotor structures and materials are investigated for the purpose of increasing machine efficiency, lifetime and loading limits. Due to complex rotor structures, high anisotropy and non-linear behavior of FRP under dynamic loads, an in-process measurement system is necessary to monitor and to investigate the evolution of damages under real operation conditions. A non-invasive, optical laser Doppler distance sensor measurement system is applied to determine the biaxial deformation of a bladed FRP rotor with micron uncertainty as well as the tangential blade vibrations at surface speeds above 300 m/s. The laser Doppler distance sensor is applicable under vacuum conditions. Measurements at varying loading conditions are used to determine elastic and plastic deformations. Furthermore they allow to determine hysteresis, fatigue, Eigenfrequency shifts and loading limits. The deformation measurements show a highly anisotropic and nonlinear behavior and offer a deeper understanding of the damage evolution in FRP rotors. The experimental results are used to validate and to calibrate a simulation model of the deformation. The simulation combines finite element analysis and a damage mechanics model. The combination of simulation and measurement system enables the monitoring and prediction of damage evolutions of FRP rotors in process.

Does targeted cognitive training reduce educational disparities in cognitive function among cognitively normal older adults?

PubMed

Clark, Daniel O; Xu, Huiping; Unverzagt, Frederick W; Hendrie, Hugh

2016-07-01

The aim of this study was to investigate educational differences in treatment responses to memory, reasoning, and speed of processing cognitive training relative to no-contact control. Secondary analyses of the Advanced Cognitive Training for Independent and Vital Elderly trial were conducted. Two thousand eight hundred older adults were randomized to memory, reasoning, or speed of processing training or no-contact control. A repeated-measures mixed-effects model was used to investigate immediate post-training and 1-year outcomes with sensitivity analyses out to 10 years. Outcomes were as follows: (1) memory composite of Hopkins Verbal Learning Test, Rey Auditory Verbal Learning Test, and Rivermead Behavioral Memory Test; (2) reasoning composite of letter series, letter sets, and word series; and (3) speed of processing measured using three trials of useful field of view and the digit symbol substitution test. The effects of reasoning and memory training did not differ by educational attainment. The effect of speed of processing training did. Those with fewer than 12 years of education experienced a 50% greater effect on the useful field of view test compared with those with 16 or more years of education. The training advantage for those with fewer than 12 years of education was maintained to 3 years post-training. Older adults with less than a secondary education are at elevated risk of dementia, including Alzheimer's disease. The analyses here indicate that speed of processing training is effective in older adults with low educational attainment. Copyright © 2015 John Wiley & Sons, Ltd.

Neurocognitive Enhancement or Impairment? A Systematic Meta-Analysis of Prescription Stimulant Effects on Processing Speed, Decision-Making, Planning, and Cognitive Perseveration

PubMed Central

Marraccini, Marisa E.; Weyandt, Lisa L.; Rossi, Joseph S.; Gudmundsdottir, Bergljot Gyda

2016-01-01

Increasing numbers of adults, particularly college students, are misusing prescription stimulants primarily for cognitive/academic enhancement, so it is critical to explore whether empirical findings support neurocognitive benefits of prescription stimulants. Previous meta-analytic studies have supported small benefits from prescription stimulants for the cognitive domains of inhibitory control and memory; however, no meta-analytic studies have examined the effects on processing speed or the potential impairment on other domains of cognition, including planning, decision-making, and cognitive perseveration. Therefore, the present study conducted a meta-analysis of the available literature examining the effects of prescription stimulants on specific measures of processing speed, planning, decision-making, and cognitive perseveration among healthy adult populations. The meta-analysis results indicated a positive influence of prescription stimulant medication on processing speed accuracy, with an overall mean effect size of g = 0.282 (95% CI 0.077, 0.488; n = 345). Neither improvements nor impairments were revealed for planning time, planning accuracy, advantageous decision-making, or cognitive perseveration; however findings are limited by the small number of studies examining these outcomes. Findings support that prescription stimulant medication may indeed act as a neurocognitive enhancer for accuracy measures of processing speed without impeding other areas of cognition. Considering that adults are already engaging in illegal use of prescription stimulants for academic enhancement, as well as the potential for stimulant misuse to have serious side effects, the establishment of public policies informed by interdisciplinary research surrounding this issue, whether restrictive or liberal, is of critical importance. PMID:27454675

High speed CMOS acquisition system based on FPGA embedded image processing for electro-optical measurements

NASA Astrophysics Data System (ADS)

Rosu-Hamzescu, Mihnea; Polonschii, Cristina; Oprea, Sergiu; Popescu, Dragos; David, Sorin; Bratu, Dumitru; Gheorghiu, Eugen

2018-06-01

Electro-optical measurements, i.e., optical waveguides and plasmonic based electrochemical impedance spectroscopy (P-EIS), are based on the sensitive dependence of refractive index of electro-optical sensors on surface charge density, modulated by an AC electrical field applied to the sensor surface. Recently, P-EIS has emerged as a new analytical tool that can resolve local impedance with high, optical spatial resolution, without using microelectrodes. This study describes a high speed image acquisition and processing system for electro-optical measurements, based on a high speed complementary metal-oxide semiconductor (CMOS) sensor and a field-programmable gate array (FPGA) board. The FPGA is used to configure CMOS parameters, as well as to receive and locally process the acquired images by performing Fourier analysis for each pixel, deriving the real and imaginary parts of the Fourier coefficients for the AC field frequencies. An AC field generator, for single or multi-sine signals, is synchronized with the high speed acquisition system for phase measurements. The system was successfully used for real-time angle-resolved electro-plasmonic measurements from 30 Hz up to 10 kHz, providing results consistent to ones obtained by a conventional electrical impedance approach. The system was able to detect amplitude variations with a relative variation of ±1%, even for rather low sampling rates per period (i.e., 8 samples per period). The PC (personal computer) acquisition and control software allows synchronized acquisition for multiple FPGA boards, making it also suitable for simultaneous angle-resolved P-EIS imaging.

Examining the locus of age effects on complex span tasks.

PubMed

McCabe, Jennifer; Hartman, Marilyn

2003-09-01

To investigate the locus of age effects on complex span tasks, the authors evaluated the contributions of working memory functions and processing speed. Age differences were found in measures of storage capacity, language processing speed, and lower level speed. Statistically controlling for each of these in hierarchical regressions substantially reduced, but did not eliminate, the complex span age effect. Accounting for lower level speed and storage, however, removed essentially the entire age effect, suggesting that both functions play important and independent roles. Additional evidence for the role of storage capacity was the absence of complex span age differences with span size calibrated to individual word span performance. Explanations for age differences based on inhibition and concurrent task performamce were not supported.

The role of reading time complexity and reading speed in text comprehension.

PubMed

Wallot, Sebastian; O'Brien, Beth A; Haussmann, Anna; Kloos, Heidi; Lyby, Marlene S

2014-11-01

Reading speed is commonly used as an index of reading fluency. However, reading speed is not a consistent predictor of text comprehension, when speed and comprehension are measured on the same text within the same reader. This might be due to the somewhat ambiguous nature of reading speed, which is sometimes regarded as a feature of the reading process, and sometimes as a product of that process. We argue that both reading speed and comprehension should be seen as the result of the reading process, and that the process of fluent text reading can instead be described by complexity metrics that quantify aspects of the stability of the reading process. In this article, we introduce complexity metrics in the context of reading and apply them to data from a self-paced reading study. In this study, children and adults read a text silently or aloud and answered comprehension questions after reading. Our results show that recurrence metrics that quantify the degree of temporal structure in reading times yield better prediction of text comprehension compared to reading speed. However, the results for fractal metrics are less clear. Furthermore, prediction of text comprehension is generally strongest and most consistent across silent and oral reading when comprehension scores are normalized by reading speed. Analyses of word length and word frequency indicate that the observed complexity in reading times is not a simple function of the lexical properties of the text, suggesting that text reading might work differently compared to reading of isolated word or sentences. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Executive functioning and processing speed in age-related differences in time estimation: a comparison of young, old, and very old adults.

PubMed

Baudouin, Alexia; Isingrini, Michel; Vanneste, Sandrine

2018-01-25

Age-related differences in time estimation were examined by comparing the temporal performance of young, young-old, and old-old adults, in relation to two major theories of cognitive aging: executive decline and cognitive slowing. We tested the hypothesis that processing speed and executive function are differentially involved in timing depending on the temporal task used. We also tested the assumption of greater age-related effects in time estimation in old-old participants. Participants performed two standard temporal tasks: duration production and duration reproduction. They also completed tests measuring executive function and processing speed. Findings supported the view that executive function is the best mediator of reproduction performance and inversely that processing speed is the best mediator of production performance. They also showed that young-old participants provide relatively accurate temporal judgments compared to old-old participants. These findings are discussed in terms of compensation mechanisms in aging.

Evidence that attitude accessibility augments the relationship between speeding attitudes and speeding behavior: a test of the MODE model in the context of driving.

PubMed

Elliott, Mark A; Lee, Emme; Robertson, Jamie S; Innes, Rhona

2015-01-01

According to the MODE model of attitude-to-behavior processes, attitude accessibility augments attitude-behavior correspondence, reflecting an automatic influence of attitudes on behavior. We therefore tested whether attitude accessibility moderates the attitude-behavior relationship in a context that is governed by characteristically automatic behavior, namely driving. In study 1 (correlational design), participants (N=130) completed online questionnaire measures of the valences and accessibilities of their attitudes towards speeding. Two weeks later, online questionnaire measures of subsequent speeding behavior were obtained. Attitude valence was a significantly better predictor of behavior at high (mean+1SD) versus low (mean-1SD) levels of attitude accessibility. In study 2 (experimental design), attitude accessibility was manipulated with a repeated attitude expression task. Immediately after the manipulation, participants (N=122) completed online questionnaire measures of attitude valence and accessibility, and two weeks later, subsequent speeding behavior. Increased attitude accessibility in the experimental (versus control) condition generated an increase in attitude-behavior correspondence. The findings are consistent with the MODE model's proposition that attitudes can exert an automatic influence on behavior. Interventions to reduce speeding could usefully increase the accessibility of anti-speeding attitudes and reduce the accessibility of pro-speeding attitudes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of automobile engine cylinder pressure and rotation speed from engine body vibration signal

NASA Astrophysics Data System (ADS)

Wang, Yuhua; Cheng, Xiang; Tan, Haishu

2016-01-01

In order to improve the engine vibration signal process method for the engine cylinder pressure and engine revolution speed measurement instrument, the engine cylinder pressure varying with the engine working cycle process has been regarded as the main exciting force for the engine block forced vibration. The forced vibration caused by the engine cylinder pressure presents as a low frequency waveform which varies with the cylinder pressure synchronously and steadily in time domain and presents as low frequency high energy discrete humorous spectrum lines in frequency domain. The engine cylinder pressure and the rotation speed can been extract form the measured engine block vibration signal by low-pass filtering analysis in time domain or by FFT analysis in frequency domain, the low-pass filtering analysis in time domain is not only suitable for the engine in uniform revolution condition but also suitable for the engine in uneven revolution condition. That provides a practical and convenient way to design motor revolution rate and cylinder pressure measurement instrument.

Longitudinal mediation of processing speed on age-related change in memory and fluid intelligence.

PubMed

Robitaille, Annie; Piccinin, Andrea M; Muniz-Terrera, Graciela; Hoffman, Lesa; Johansson, Boo; Deeg, Dorly J H; Aartsen, Marja J; Comijs, Hannie C; Hofer, Scott M

2013-12-01

Age-related decline in processing speed has long been considered a key driver of cognitive aging. While the majority of empirical evidence for the processing speed hypothesis has been obtained from analyses of between-person age differences, longitudinal studies provide a direct test of within-person change. Using recent developments in longitudinal mediation analysis, we examine the speed-mediation hypothesis at both the within-and between-person levels in two longitudinal studies, Longitudinal Aging Study Amsterdam (LASA) and Origins of Variance in the Oldest-Old (OCTO-Twin). We found significant within-person indirect effects of change in age, such that increasing age was related to lower speed, which in turn relates to lower performance across repeated measures on other cognitive outcomes. Although between-person indirect effects were also significant in LASA, they were not in OCTO-Twin which is not unexpected given the age homogeneous nature of the OCTO-Twin data. A more in-depth examination through measures of effect size suggests that, for the LASA study, the within-person indirect effects were small and between-person indirect effects were consistently larger. These differing magnitudes of direct and indirect effects across levels demonstrate the importance of separating between- and within-person effects in evaluating theoretical models of age-related change. PsycINFO Database Record (c) 2013 APA, all rights reserved.

High-Speed On-Board Data Processing for Science Instruments

NASA Technical Reports Server (NTRS)

Beyon, Jeffrey Y.; Ng, Tak-Kwong; Lin, Bing; Hu, Yongxiang; Harrison, Wallace

2014-01-01

A new development of on-board data processing platform has been in progress at NASA Langley Research Center since April, 2012, and the overall review of such work is presented in this paper. The project is called High-Speed On-Board Data Processing for Science Instruments (HOPS) and focuses on a high-speed scalable data processing platform for three particular National Research Council's Decadal Survey missions such as Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS), Aerosol-Cloud-Ecosystems (ACE), and Doppler Aerosol Wind Lidar (DAWN) 3-D Winds. HOPS utilizes advanced general purpose computing with Field Programmable Gate Array (FPGA) based algorithm implementation techniques. The significance of HOPS is to enable high speed on-board data processing for current and future science missions with its reconfigurable and scalable data processing platform. A single HOPS processing board is expected to provide approximately 66 times faster data processing speed for ASCENDS, more than 70% reduction in both power and weight, and about two orders of cost reduction compared to the state-of-the-art (SOA) on-board data processing system. Such benchmark predictions are based on the data when HOPS was originally proposed in August, 2011. The details of these improvement measures are also presented. The two facets of HOPS development are identifying the most computationally intensive algorithm segments of each mission and implementing them in a FPGA-based data processing board. A general introduction of such facets is also the purpose of this paper.

Toward a research-based assessment of dyslexia: using cognitive measures to identify reading disabilities.

PubMed

Bell, Sherry Mee; McCallum, R Steve; Cox, Elizabeth A

2003-01-01

One hundred five participants from a random sample of elementary and middle school children completed measures of reading achievement and cognitive abilities presumed, based on a synthesis of current dyslexia research, to underlie reading. Factor analyses of these cognitive variables (including auditory processing, phonological awareness, short-term auditory memory, visual memory, rapid automatized naming, and visual processing speed) produced three empirically and theoretically derived factors (auditory processing, visual processing/speed, and memory), each of which contributed to the prediction of reading and spelling skills. Factor scores from the three factors combined predicted 85% of the variance associated with letter/sight word naming, 70% of the variance associated with reading comprehension, 73% for spelling, and 61% for phonetic decoding. The auditory processing factor was the strongest predictor, accounting for 27% to 43% of the variance across the different achievement areas. The results provide practitioner and researcher with theoretical and empirical support for the inclusion of measures of the three factors, in addition to specific measures of reading achievement, in a standardized assessment of dyslexia. Guidelines for a thorough, research-based assessment are provided.

Modeling the Covariance Structure of Complex Datasets Using Cognitive Models: An Application to Individual Differences and the Heritability of Cognitive Ability.

PubMed

Evans, Nathan J; Steyvers, Mark; Brown, Scott D

2018-06-05

Understanding individual differences in cognitive performance is an important part of understanding how variations in underlying cognitive processes can result in variations in task performance. However, the exploration of individual differences in the components of the decision process-such as cognitive processing speed, response caution, and motor execution speed-in previous research has been limited. Here, we assess the heritability of the components of the decision process, with heritability having been a common aspect of individual differences research within other areas of cognition. Importantly, a limitation of previous work on cognitive heritability is the underlying assumption that variability in response times solely reflects variability in the speed of cognitive processing. This assumption has been problematic in other domains, due to the confounding effects of caution and motor execution speed on observed response times. We extend a cognitive model of decision-making to account for relatedness structure in a twin study paradigm. This approach can separately quantify different contributions to the heritability of response time. Using data from the Human Connectome Project, we find strong evidence for the heritability of response caution, and more ambiguous evidence for the heritability of cognitive processing speed and motor execution speed. Our study suggests that the assumption made in previous studies-that the heritability of cognitive ability is based on cognitive processing speed-may be incorrect. More generally, our methodology provides a useful avenue for future research in complex data that aims to analyze cognitive traits across different sources of related data, whether the relation is between people, tasks, experimental phases, or methods of measurement. © 2018 Cognitive Science Society, Inc.

Design of Control Software for a High-Speed Coherent Doppler Lidar System for CO2 Measurement

NASA Technical Reports Server (NTRS)

Vanvalkenburg, Randal L.; Beyon, Jeffrey Y.; Koch, Grady J.; Yu, Jirong; Singh, Upendra N.; Kavaya, Michael J.

2010-01-01

The design of the software for a 2-micron coherent high-speed Doppler lidar system for CO2 measurement at NASA Langley Research Center is discussed in this paper. The specific strategy and design topology to meet the requirements of the system are reviewed. In order to attain the high-speed digitization of the different types of signals to be sampled on multiple channels, a carefully planned design of the control software is imperative. Samples of digitized data from each channel and their roles in data analysis post processing are also presented. Several challenges of extremely-fast, high volume data acquisition are discussed. The software must check the validity of each lidar return as well as other monitoring channel data in real-time. For such high-speed data acquisition systems, the software is a key component that enables the entire scope of CO2 measurement studies using commercially available system components.

Measurement of Rotating Blade Tip Clearance with Fibre-Optic Probe

NASA Astrophysics Data System (ADS)

Cao, S. Z.; Duan, F. J.; Zhang, Y. G.

2006-10-01

This paper described a tip clearance measuring system with fibre-optic probe. The system is based on a novel tip clearance sensor of optical fibre-bundle mounted on the casing, rotating speed synchronization sensor mounted on the rotating shaft, the tip clearance preamplification processing circuit followed by high speed data-acquisition unit. A novel tip clearance sensor of trifurcated optical fibre bundle was proposed and demonstrated. It is independent of material of measured surface but capacitive probe demands target conductive. Measurements can be taken under severe conditions such as ionization. Sensor circuitry and data acquisition circuit were successfully designed. With the help of Rotation synchronized sensor, all the blades can be detected in real-time. Because of fibre-optic sensor, the measuring system has commendably frequency response, which can work well in high rotating speed from 0-15000rpm.The measurement range of tip clearance is 0-3mm with 25um precision.

Cognitive Processing Speed, Working Memory, and the Intelligibility of Hearing Aid-Processed Speech in Persons with Hearing Impairment

PubMed Central

Yumba, Wycliffe Kabaywe

2017-01-01

Previous studies have demonstrated that successful listening with advanced signal processing in digital hearing aids is associated with individual cognitive capacity, particularly working memory capacity (WMC). This study aimed to examine the relationship between cognitive abilities (cognitive processing speed and WMC) and individual listeners’ responses to digital signal processing settings in adverse listening conditions. A total of 194 native Swedish speakers (83 women and 111 men), aged 33–80 years (mean = 60.75 years, SD = 8.89), with bilateral, symmetrical mild to moderate sensorineural hearing loss who had completed a lexical decision speed test (measuring cognitive processing speed) and semantic word-pair span test (SWPST, capturing WMC) participated in this study. The Hagerman test (capturing speech recognition in noise) was conducted using an experimental hearing aid with three digital signal processing settings: (1) linear amplification without noise reduction (NoP), (2) linear amplification with noise reduction (NR), and (3) non-linear amplification without NR (“fast-acting compression”). The results showed that cognitive processing speed was a better predictor of speech intelligibility in noise, regardless of the types of signal processing algorithms used. That is, there was a stronger association between cognitive processing speed and NR outcomes and fast-acting compression outcomes (in steady state noise). We observed a weaker relationship between working memory and NR, but WMC did not relate to fast-acting compression. WMC was a relatively weaker predictor of speech intelligibility in noise. These findings might have been different if the participants had been provided with training and or allowed to acclimatize to binary masking noise reduction or fast-acting compression. PMID:28861009

Note: Fully integrated 3.2 Gbps quantum random number generator with real-time extraction

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

Zhang, Xiao-Guang; Nie, You-Qi; Liang, Hao

2016-07-15

We present a real-time and fully integrated quantum random number generator (QRNG) by measuring laser phase fluctuations. The QRNG scheme based on laser phase fluctuations is featured for its capability of generating ultra-high-speed random numbers. However, the speed bottleneck of a practical QRNG lies on the limited speed of randomness extraction. To close the gap between the fast randomness generation and the slow post-processing, we propose a pipeline extraction algorithm based on Toeplitz matrix hashing and implement it in a high-speed field-programmable gate array. Further, all the QRNG components are integrated into a module, including a compact and actively stabilizedmore » interferometer, high-speed data acquisition, and real-time data post-processing and transmission. The final generation rate of the QRNG module with real-time extraction can reach 3.2 Gbps.« less

Does silent reading speed in normal adult readers depend on early visual processes? evidence from event-related brain potentials.

PubMed

Korinth, Sebastian Peter; Sommer, Werner; Breznitz, Zvia

2012-01-01

Little is known about the relationship of reading speed and early visual processes in normal readers. Here we examined the association of the early P1, N170 and late N1 component in visual event-related potentials (ERPs) with silent reading speed and a number of additional cognitive skills in a sample of 52 adult German readers utilizing a Lexical Decision Task (LDT) and a Face Decision Task (FDT). Amplitudes of the N170 component in the LDT but, interestingly, also in the FDT correlated with behavioral tests measuring silent reading speed. We suggest that reading speed performance can be at least partially accounted for by the extraction of essential structural information from visual stimuli, consisting of a domain-general and a domain-specific expertise-based portion. © 2011 Elsevier Inc. All rights reserved.

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.

Ultrasonic Shear Wave Elasticity Imaging (SWEI) Sequencing and Data Processing Using a Verasonics Research Scanner

PubMed Central

Deng, Yufeng; Rouze, Ned C.; Palmeri, Mark L.; Nightingale, Kathryn R.

2017-01-01

Ultrasound elasticity imaging has been developed over the last decade to estimate tissue stiffness. Shear wave elasticity imaging (SWEI) quantifies tissue stiffness by measuring the speed of propagating shear waves following acoustic radiation force excitation. This work presents the sequencing and data processing protocols of SWEI using a Verasonics system. The selection of the sequence parameters in a Verasonics programming script is discussed in detail. The data processing pipeline to calculate group shear wave speed (SWS), including tissue motion estimation, data filtering, and SWS estimation is demonstrated. In addition, the procedures for calibration of beam position, scanner timing, and transducer face heating are provided to avoid SWS measurement bias and transducer damage. PMID:28092508

Imaging of sound speed using reflection ultrasound tomography.

PubMed

Nebeker, Jakob; Nelson, Thomas R

2012-09-01

The goal of this work was to obtain and evaluate measurements of tissue sound speed in the breast, particularly dense breasts, using backscatter ultrasound tomography. An automated volumetric breast ultrasound scanner was constructed for imaging the prone patient. A 5- to 7-MHz linear array transducer acquired 17,920 radiofrequency pulse echo A-lines from the breast, and a back-wall reflector rotated over 360° in 25 seconds. Sound speed images used reflector echoes that after preprocessing were uploaded into a graphics processing unit for filtered back-projection reconstruction. A velocimeter also was constructed to measure the sound speed and attenuation for comparison to scanner performance. Measurements were made using the following: (1) deionized water from 22°C to 90°C; (2) various fluids with sound speeds from 1240 to 1904 m/s; (3) acrylamide gel test objects with features from 1 to 15 mm in diameter; and (4) healthy volunteers. The mean error ± SD between sound speed reference and image data was -0.48% ± 9.1%, and the error between reference and velocimeter measurements was -1.78% ± 6.50%. Sound speed image and velocimeter measurements showed a difference of 0.10% ± 4.04%. Temperature data showed a difference between theory and imaging performance of -0.28% ± 0.22%. Images of polyacrylamide test objects showed detectability of an approximately 1% sound speed difference in a 2.4-mm cylindrical inclusion with a contrast to noise ratio of 7.9 dB. An automated breast scanner offers the potential to make consistent automated tomographic images of breast backscatter, sound speed, and attenuation, potentially improving diagnosis, particularly in dense breasts.

Evidence that communication impairment in schizophrenia is associated with generalized poor task performance.

PubMed

Merrill, Anne M; Karcher, Nicole R; Cicero, David C; Becker, Theresa M; Docherty, Anna R; Kerns, John G

2017-03-01

People with schizophrenia exhibit wide-ranging cognitive deficits, including slower processing speed and decreased cognitive control. Disorganized speech symptoms, such as communication impairment, have been associated with poor cognitive control task performance (e.g., goal maintenance and working memory). Whether communication impairment is associated with poorer performance on a broader range of non-cognitive control measures is unclear. In the current study, people with schizophrenia (n =51) and non-psychiatric controls (n =26) completed speech interviews allowing for reliable quantitative assessment of communication impairment. Participants also completed multiple goal maintenance and working memory tasks. In addition, we also examined (a) simple measures of processing speed involving highly automatic prepotent responses and (b) a non-cognitive control measure of general task performance. Schizophrenia communication impairment was significantly associated with poor performance in all cognitive domains, with the largest association found with processing speed (r s =-0.52). Further, communication impairment was also associated with the non-cognitive control measure of poor general task performance (r s =-0.43). In contrast, alogia, a negative speech symptom, and positive symptoms were less if at all related to cognitive task performance. Overall, this study suggests that communication impairment in schizophrenia may be associated with relatively generalized poor cognitive task performance. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Comorbidity between reading disability and math disability: concurrent psychopathology, functional impairment, and neuropsychological functioning.

PubMed

Willcutt, Erik G; Petrill, Stephen A; Wu, Sarah; Boada, Richard; Defries, John C; Olson, Richard K; Pennington, Bruce F

2013-01-01

Reading disability (RD) and math disability (MD) frequently co-occur, but the etiology of this comorbidity is not well understood. Groups with RD only (N = 241), MD only (N = 183), and RD + MD (N = 188) and a control group with neither disorder (N = 411) completed a battery of measures of internalizing and externalizing psychopathology, social and academic functioning, and 10 neuropsychological processes. Groups with RD only, MD only, and RD + MD were significantly impaired versus the control group on nearly all measures, and the group with RD + MD was more impaired than the groups with MD and RD alone on measures of internalizing psychopathology, academic functioning, and 7 of 10 neuropsychological constructs. Multiple regression analyses of the neuropsychological measures indicated that deficits in reading and math were associated with shared weaknesses in working memory, processing speed, and verbal comprehension. In contrast, reading difficulties were uniquely associated with weaknesses in phoneme awareness and naming speed, and math deficits were uniquely associated with weaknesses in set shifting. These results support multiple-deficit neuropsychological models of RD and MD and suggest that RD and MD are distinct but related disorders that co-occur because of shared neuropsychological weaknesses in working memory, processing speed, and verbal comprehension.

Speed skills: measuring the visual speed analyzing properties of primate MT neurons.

PubMed

Perrone, J A; Thiele, A

2001-05-01

Knowing the direction and speed of moving objects is often critical for survival. However, it is poorly understood how cortical neurons process the speed of image movement. Here we tested MT neurons using moving sine-wave gratings of different spatial and temporal frequencies, and mapped out the neurons' spatiotemporal frequency response profiles. The maps typically had oriented ridges of peak sensitivity as expected for speed-tuned neurons. The preferred speed estimate, derived from the orientation of the maps, corresponded well to the preferred speed when moving bars were presented. Thus, our data demonstrate that MT neurons are truly sensitive to the object speed. These findings indicate that MT is not only a key structure in the analysis of direction of motion and depth perception, but also in the analysis of object speed.

Exhaust pressure pulsation observation from turbocharger instantaneous speed measurement

NASA Astrophysics Data System (ADS)

Macián, V.; Luján, J. M.; Bermúdez, V.; Guardiola, C.

2004-06-01

In internal combustion engines, instantaneous exhaust pressure measurements are difficult to perform in a production environment. The high temperature of the exhaust manifold and its pulsating character make its application to exhaust gas recirculation control algorithms impossible. In this paper an alternative method for estimating the exhaust pressure pulsation is presented. A numerical model is built which enables the exhaust pressure pulses to be predicted from instantaneous turbocharger speed measurements. Although the model is data based, a theoretical description of the process is also provided. This combined approach makes it possible to export the model for different engine operating points. Also, compressor contribution in the turbocharger speed pulsation is discussed extensively. The compressor contribution is initially neglected, and effects of this simplified approach are analysed.

Inattentive behaviour is associated with poor working memory and slow processing speed in very pre-term children in middle childhood.

PubMed

Mulder, Hanna; Pitchford, Nicola J; Marlow, Neil

2011-03-01

BACKGROUND. Problem behaviour is common following pre-term birth, but the underlying nature of these difficulties is not well known. AIMS. We sought to establish the mechanisms underpinning behavioural difficulties in very pre-term (VPT) children in middle childhood by comparing their performance to that of term born peers on tasks of working memory, inhibition, and processing speed, and relating these to parent and teacher assessments of their behaviour. Particular focus was given to inattention and overactive/impulsive behaviour, as these behaviours have been associated with different neuropsychological problems in term children. SAMPLES. A group of VPT children (gestational age < 31 weeks, N= 56) aged 9-10 years and term controls (N= 22) participated in the study. METHOD. Children were assessed with measures of working memory, inhibition, and processing speed. Parents and teachers reported behavioural problems using the Strengths and Difficulties Questionnaire and two additional scales measuring overactive/impulsive behaviour and inattention. RESULTS. Results revealed increased rates of problem behaviour in VPT compared to term children for parent-rated total difficulties, hyperactivity, emotional problems, peer problems, prosocial behaviour, overactive/impulsive behaviour, and parent- and teacher-rated inattention. Processing speed and working memory, but not inhibition, were significantly related to inattentive and overactive/impulsive behaviour. CONCLUSIONS. The increased rates of inattention and overactive/impulsive behaviour in VPT children may be explained by impairment in processing speed and working memory. Expected links between overactive/impulsive behaviour and inhibitory control were not identified, suggesting the nature of such difficulties may be different in VPT compared to term children. © 2010 The British Psychological Society.

Brain training game improves executive functions and processing speed in the elderly: a randomized controlled trial.

PubMed

Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Akitsuki, Yuko; Shigemune, Yayoi; Sekiguchi, Atsushi; Kotozaki, Yuka; Tsukiura, Takashi; Yomogida, Yukihito; Kawashima, Ryuta

2012-01-01

The beneficial effects of brain training games are expected to transfer to other cognitive functions, but these beneficial effects are poorly understood. Here we investigate the impact of the brain training game (Brain Age) on cognitive functions in the elderly. Thirty-two elderly volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). This study was completed by 14 of the 16 members in the Brain Age group and 14 of the 16 members in the Tetris group. To maximize the benefit of the interventions, all participants were non-gamers who reported playing less than one hour of video games per week over the past 2 years. Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Each group played for a total of about 20 days. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into four categories (global cognitive status, executive functions, attention, and processing speed). Results showed that the effects of the brain training game were transferred to executive functions and to processing speed. However, the brain training game showed no transfer effect on any global cognitive status nor attention. Our results showed that playing Brain Age for 4 weeks could lead to improve cognitive functions (executive functions and processing speed) in the elderly. This result indicated that there is a possibility which the elderly could improve executive functions and processing speed in short term training. The results need replication in large samples. Long-term effects and relevance for every-day functioning remain uncertain as yet. UMIN Clinical Trial Registry 000002825.

Neurocognitive enhancement or impairment? A systematic meta-analysis of prescription stimulant effects on processing speed, decision-making, planning, and cognitive perseveration.

PubMed

Marraccini, Marisa E; Weyandt, Lisa L; Rossi, Joseph S; Gudmundsdottir, Bergljot Gyda

2016-08-01

Increasing numbers of adults, particularly college students, are misusing prescription stimulants primarily for cognitive/academic enhancement, so it is critical to explore whether empirical findings support neurocognitive benefits of prescription stimulants. Previous meta-analytic studies have supported small benefits from prescription stimulants for the cognitive domains of inhibitory control and memory; however, no meta-analytic studies have examined the effects on processing speed or the potential impairment on other domains of cognition, including planning, decision-making, and cognitive perseveration. Therefore, the present study conducted a meta-analysis of the available literature examining the effects of prescription stimulants on specific measures of processing speed, planning, decision-making, and cognitive perseveration among healthy adult populations. The meta-analysis results indicated a positive influence of prescription stimulant medication on processing speed accuracy, with an overall mean effect size of g = 0.282 (95% CI [0.077, 0.488]; n = 345). Neither improvements nor impairments were revealed for planning time, planning accuracy, advantageous decision-making, or cognitive perseveration; however, findings are limited by the small number of studies examining these outcomes. Findings support that prescription stimulant medication may indeed act as a neurocognitive enhancer for accuracy measures of processing speed without impeding other areas of cognition. Considering that adults are already engaging in illegal use of prescription stimulants for academic enhancement, as well as the potential for stimulant misuse to have serious side effects, the establishment of public policies informed by interdisciplinary research surrounding this issue, whether restrictive or liberal, is of critical importance. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Accuracy improvement of multimodal measurement of speed of sound based on image processing

NASA Astrophysics Data System (ADS)

Nitta, Naotaka; Kaya, Akio; Misawa, Masaki; Hyodo, Koji; Numano, Tomokazu

2017-07-01

Since the speed of sound (SOS) reflects tissue characteristics and is expected as an evaluation index of elasticity and water content, the noninvasive measurement of SOS is eagerly anticipated. However, it is difficult to measure the SOS by using an ultrasound device alone. Therefore, we have presented a noninvasive measurement method of SOS using ultrasound (US) and magnetic resonance (MR) images. By this method, we determine the longitudinal SOS based on the thickness measurement using the MR image and the time of flight (TOF) measurement using the US image. The accuracy of SOS measurement is affected by the accuracy of image registration and the accuracy of thickness measurements in the MR and US images. In this study, we address the accuracy improvement in the latter thickness measurement, and present an image-processing-based method for improving the accuracy of thickness measurement. The method was investigated by using in vivo data obtained from a tissue-engineered cartilage implanted in the back of a rat, with an unclear boundary.

Image processing for safety assessment in civil engineering.

PubMed

Ferrer, Belen; Pomares, Juan C; Irles, Ramon; Espinosa, Julian; Mas, David

2013-06-20

Behavior analysis of construction safety systems is of fundamental importance to avoid accidental injuries. Traditionally, measurements of dynamic actions in civil engineering have been done through accelerometers, but high-speed cameras and image processing techniques can play an important role in this area. Here, we propose using morphological image filtering and Hough transform on high-speed video sequence as tools for dynamic measurements on that field. The presented method is applied to obtain the trajectory and acceleration of a cylindrical ballast falling from a building and trapped by a thread net. Results show that safety recommendations given in construction codes can be potentially dangerous for workers.

Objectively-Measured Physical Activity and Cognitive Functioning in Breast Cancer Survivors

PubMed Central

Marinac, Catherine R.; Godbole, Suneeta; Kerr, Jacqueline; Natarajan, Loki; Patterson, Ruth E.; Hartman, Sheri J.

2015-01-01

Purpose To explore the relationship between objectively measured physical activity and cognitive functioning in breast cancer survivors. Methods Participants were 136 postmenopausal breast cancer survivors. Cognitive functioning was assessed using a comprehensive computerized neuropsychological test. 7-day physical activity was assessed using hip-worn accelerometers. Linear regression models examined associations of minutes per day of physical activity at various intensities on individual cognitive functioning domains. The partially adjusted model controlled for primary confounders (model 1), and subsequent adjustments were made for chemotherapy history (model 2), and BMI (model 3). Interaction and stratified models examined BMI as an effect modifier. Results Moderate-to-vigorous physical activity (MVPA) was associated with Information Processing Speed. Specifically, ten minutes of MVPA was associated with a 1.35-point higher score (out of 100) on the Information Processing Speed domain in the partially adjusted model, and a 1.29-point higher score when chemotherapy was added to the model (both p<.05). There was a significant BMI x MVPA interaction (p=.051). In models stratified by BMI (<25 vs. ≥25 kg/m2), the favorable association between MVPA and Information Processing Speed was stronger in the subsample of overweight and obese women (p<.05), but not statistically significant in the leaner subsample. Light-intensity physical activity was not significantly associated with any of the measured domains of cognitive function. Conclusions MVPA may have favorable effects on Information Processing Speed in breast cancer survivors, particularly among overweight or obese women. Implications for Cancer Survivors Interventions targeting increased physical activity may enhance aspects of cognitive function among breast cancer survivors. PMID:25304986

Using floating car data to analyse the effects of its measures and eco-driving.

PubMed

Garcia-Castro, Alvaro; Monzon, Andres

2014-11-11

The road transportation sector is responsible for around 25% of total man-made CO2 emissions worldwide. Considerable efforts are therefore underway to reduce these emissions using several approaches, including improved vehicle technologies, traffic management and changing driving behaviour. Detailed traffic and emissions models are used extensively to assess the potential effects of these measures. However, if the input and calibration data are not sufficiently detailed there is an inherent risk that the results may be inaccurate. This article presents the use of Floating Car Data to derive useful speed and acceleration values in the process of traffic model calibration as a means of ensuring more accurate results when simulating the effects of particular measures. The data acquired includes instantaneous GPS coordinates to track and select the itineraries, and speed and engine performance extracted directly from the on-board diagnostics system. Once the data is processed, the variations in several calibration parameters can be analyzed by comparing the base case model with the measure application scenarios. Depending on the measure, the results show changes of up to 6.4% in maximum speed values, and reductions of nearly 15% in acceleration and braking levels, especially when eco-driving is applied.

Using Floating Car Data to Analyse the Effects of ITS Measures and Eco-Driving

PubMed Central

Garcia-Castro, Alvaro; Monzon, Andres

2014-01-01

The road transportation sector is responsible for around 25% of total man-made CO2 emissions worldwide. Considerable efforts are therefore underway to reduce these emissions using several approaches, including improved vehicle technologies, traffic management and changing driving behaviour. Detailed traffic and emissions models are used extensively to assess the potential effects of these measures. However, if the input and calibration data are not sufficiently detailed there is an inherent risk that the results may be inaccurate. This article presents the use of Floating Car Data to derive useful speed and acceleration values in the process of traffic model calibration as a means of ensuring more accurate results when simulating the effects of particular measures. The data acquired includes instantaneous GPS coordinates to track and select the itineraries, and speed and engine performance extracted directly from the on-board diagnostics system. Once the data is processed, the variations in several calibration parameters can be analyzed by comparing the base case model with the measure application scenarios. Depending on the measure, the results show changes of up to 6.4% in maximum speed values, and reductions of nearly 15% in acceleration and braking levels, especially when eco-driving is applied. PMID:25393787

Shear wave speed and dispersion measurements using crawling wave chirps.

PubMed

Hah, Zaegyoo; Partin, Alexander; Parker, Kevin J

2014-10-01

This article demonstrates the measurement of shear wave speed and shear speed dispersion of biomaterials using a chirp signal that launches waves over a range of frequencies. A biomaterial is vibrated by two vibration sources that generate shear waves inside the medium, which is scanned by an ultrasound imaging system. Doppler processing of the acquired signal produces an image of the square of vibration amplitude that shows repetitive constructive and destructive interference patterns called "crawling waves." With a chirp vibration signal, successive Doppler frames are generated from different source frequencies. Collected frames generate a distinctive pattern which is used to calculate the shear speed and shear speed dispersion. A special reciprocal chirp is designed such that the equi-phase lines of a motion slice image are straight lines. Detailed analysis is provided to generate a closed-form solution for calculating the shear wave speed and the dispersion. Also several phantoms and an ex vivo human liver sample are scanned and the estimation results are presented. © The Author(s) 2014.

Ultrafast shock compression of an oxygen-balanced mixture of nitromethane and hydrogen peroxide.

PubMed

Armstrong, Michael R; Zaug, Joseph M; Grant, Christian D; Crowhurst, Jonathan C; Bastea, Sorin

2014-08-14

We apply ultrafast optical interferometry to measure the Hugoniot of an oxygen-balanced mixture of nitromethane and hydrogen peroxide (NM/HP) and compare with Hugoniot data for pure nitromethane (NM) and a 90% hydrogen peroxide/water mixture (HP), as well as theoretical predictions. We observe a 2.1% percent mean pairwise difference between the measured shockwave speed (at the measured piston speed) in unreacted NM/HP and the corresponding "universal" liquid Hugoniot, which is larger than the average standard deviation of our data, 1.4%. Unlike the Hugoniots of both HP and NM, in which measured shock speeds deviate to values greater than the unreacted Hugoniot for piston speeds larger than the respective reaction thresholds, in the NM/HP mixture we observe shock speed deviations to values lower than the unreacted Hugoniot well below the von Neumann pressure (≈28 GPa). Although the trend should reverse for high enough piston speeds, the initial behavior is unexpected. Possible explanations range from mixing effects to a complex index of refraction in the reacted solution. If this is indeed a signature of chemical initiation, it would suggest that the process may not be kinetically limited (on a ~100 ps time scale) between the initiation threshold and the von Neumann pressure.

Developmental trends in infant temporal processing speed.

PubMed

Saint, Sarah E; Hammond, Billy R; O'Brien, Kevin J; Frick, Janet E

2017-09-01

Processing speed, which can be measured behaviorally in various sensory domains, has been shown to be a strong marker of central nervous system health and functioning in adults. Visual temporal processing speed (measured via critical flicker fusion [CFF] thresholds) represents the maximum speed at which the visual system can detect changes. Previous studies of infant CFF development have been limited and inconsistent. The present study sought to characterize the development of CFF thresholds in the first year of life using a larger sample than previous studies and a repeated measures design (in Experiment 2) to control for individual differences. Experiment 1 (n=44 infants and n=24 adults) used a cross-sectional design aimed at examining age-related changes that exist in CFF thresholds across infants during the first year of life. Adult data were collected to give context to infant CFF thresholds obtained under our specific stimulus conditions. Experiment 2 (N=28) used a repeated-measures design to characterize the developmental trajectory of infant CFF thresholds between three and six months of age, based on the results of Experiment 1. Our results reveal a general increase in CFF from three to four and one-half months of age, with a high degree of variability within each age group. Infant CFF thresholds at 4.5months of age were not significantly different from the adult average, though a regression analysis of the data from Experiment 2 predicted that infants would reach the adult average closer to 6months of age. Developmental and clinical implications of these data are discussed. Published by Elsevier Ltd.

The puzzle of processing speed, memory, and executive function impairments in schizophrenia: fitting the pieces together.

PubMed

Knowles, Emma E M; Weiser, Mark; David, Anthony S; Glahn, David C; Davidson, Michael; Reichenberg, Abraham

2015-12-01

Substantial impairment in performance on the digit-symbol substitution task in patients with schizophrenia is well established, which has been widely interpreted as denoting a specific impairment in processing speed. However, other higher order cognitive functions might be more critical to performance on this task. To date, this idea has not been rigorously investigated in patients with schizophrenia. Neuropsychological measures of processing speed, memory, and executive functioning were completed by 125 patients with schizophrenia and 272 control subjects. We implemented a series of confirmatory factor and structural regression modeling to build an integrated model of processing speed, memory, and executive function with which to deconstruct the digit-symbol substitution task and characterize discrepancies between patients with schizophrenia and control subjects. The overall structure of the processing speed, memory, and executive function model was the same across groups (χ(2) = 208.86, p > .05), but the contribution of the specific cognitive domains to coding task performance differed significantly. When completing the task, control subjects relied on executive function and, indirectly, on working memory ability, whereas patients with schizophrenia used an alternative set of cognitive operations whereby they relied on the same processes required to complete verbal fluency tasks. Successful coding task performance relies predominantly on executive function, rather than processing speed or memory. Patients with schizophrenia perform poorly on this task because of an apparent lack of appropriate executive function input; they rely instead on an alternative cognitive pathway. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Visual Processing in Rapid-Chase Systems: Image Processing, Attention, and Awareness

PubMed Central

Schmidt, Thomas; Haberkamp, Anke; Veltkamp, G. Marina; Weber, Andreas; Seydell-Greenwald, Anna; Schmidt, Filipp

2011-01-01

Visual stimuli can be classified so rapidly that their analysis may be based on a single sweep of feedforward processing through the visuomotor system. Behavioral criteria for feedforward processing can be evaluated in response priming tasks where speeded pointing or keypress responses are performed toward target stimuli which are preceded by prime stimuli. We apply this method to several classes of complex stimuli. (1) When participants classify natural images into animals or non-animals, the time course of their pointing responses indicates that prime and target signals remain strictly sequential throughout all processing stages, meeting stringent behavioral criteria for feedforward processing (rapid-chase criteria). (2) Such priming effects are boosted by selective visual attention for positions, shapes, and colors, in a way consistent with bottom-up enhancement of visuomotor processing, even when primes cannot be consciously identified. (3) Speeded processing of phobic images is observed in participants specifically fearful of spiders or snakes, suggesting enhancement of feedforward processing by long-term perceptual learning. (4) When the perceived brightness of primes in complex displays is altered by means of illumination or transparency illusions, priming effects in speeded keypress responses can systematically contradict subjective brightness judgments, such that one prime appears brighter than the other but activates motor responses as if it was darker. We propose that response priming captures the output of the first feedforward pass of visual signals through the visuomotor system, and that this output lacks some characteristic features of more elaborate, recurrent processing. This way, visuomotor measures may become dissociated from several aspects of conscious vision. We argue that “fast” visuomotor measures predominantly driven by feedforward processing should supplement “slow” psychophysical measures predominantly based on visual awareness. PMID:21811484

Time-Dependent Effects of Acute Exercise on University Students’ Cognitive Performance in Temperate and Cold Environments

PubMed Central

Ji, Ling-Yu; Li, Xiao-Ling; Liu, Yang; Sun, Xiu-Wen; Wang, Hui-Fen; Chen, Long; Gao, Liang

2017-01-01

Background: Few studies have examined the acute exercise-induced changes in cognitive performance in different thermal environments and the time course effects. Objective: Investigate the time-dependent effects of acute exercise on university students’ processing speed, working memory and cognitive flexibility in temperate and cold environments. Method: Twenty male university students (age 23.5 ± 2.0 years) with moderate physical activity level participated in a repeated-measures within-subjects design. Processing speed, working memory and cognitive flexibility were assessed using CogState test battery at baseline (BASE), followed by a 45-min rest (REST), immediately after (EX) and 30 min after (POST-EX) 30-min moderate-intensity treadmill running in both temperate (TEMP; 25°C) and cold (COLD; 10°C) environments. Mean skin temperature (MST) and thermal sensation (TS) were also recorded. Two-way repeated measures ANOVA was performed to analyze each variable. Spearman’s rho was used to identify the correlations between MST, TS and cognitive performance. Results: Reaction time (RT) of processing speed and working memory decreased immediately after exercise in both conditions (processing speed: p = 0.003; working memory: p = 0.007). The facilitating effects on processing speed disappeared within 30 min after exercise in TEMP (p = 0.163) and COLD (p = 0.667), while improvements on working memory remained 30 min after exercise in TEMP (p = 0.047), but not in COLD (p = 0.663). Though RT of cognitive flexibility reduced in both conditions (p = 0.003), no significance was found between EX and REST (p = 0.135). Increased MST and TS were significantly associated with reductions in processing speed RT (MST: r = -0.341, p < 0.001; TS: r = -0.262, p = 0.001) and working memory RT (MST: r = -0.282, p < 0.001; TS: r = -0.2229, p = 0.005), and improvements in working memory accuracy (MST: r = 0.249, p = 0.002; TS: r = 0.255, p = 0.001). Conclusion: The results demonstrate different time-dependent effects of acute exercise on cognition in TEMP and COLD. Our study reveals facilitating effects of exercise on university students’ processing speed and working memory in both environments. However, in contrast to TEMP, effects on working memory in COLD are transient. PMID:28747896

Research on Dynamic Torque Measurement of High Speed Rotating Axis Based on Whole Optical Fiber Technique

NASA Astrophysics Data System (ADS)

Ma, H. P.; Jin, Y. Q.; Ha, Y. W.; Liu, L. H.

2006-10-01

Non-contact torque measurement system of fiber grating is proposed in this paper. It is used for the dynamic torque measurement of the rotating axis in the spaceflight servo system. Optical fiber is used as sensing probe with high sensitivity, anti-electromagnetic interference, resistance to high temperature and corrosion. It is suitable to apply in a bad environment. Signals are processed by digital circuit and Single Chip Microcomputer. This project can realize super speed dynamic measurement and it is the first time to apply the project in the spaceflight system.

The double-deficit hypothesis: a comprehensive analysis of the evidence.

PubMed

Vukovic, Rose K; Siegel, Linda S

2006-01-01

The double-deficit hypothesis of developmental dyslexia proposes that deficits in phonological processing and naming speed represent independent sources of dysfunction in dyslexia. The present article is a review of the evidence for the double-deficit hypothesis, including a discussion of recent findings related to the hypothesis. Studies in this area have been characterized by variability in methodology--how dyslexia is defined and identified, and how dyslexia subtypes are classified. Such variability sets limitations on the extent to which conclusions may be drawn with respect to the double-deficit hypothesis. Furthermore, the literature is complicated by the persistent finding that measures of phonological processing and naming speed are significantly correlated, resulting in a statistical artifact that makes it difficult to disentangle the influence of naming speed from that of phonological processing. Longitudinal and intervention studies of the double-deficit hypothesis are needed to accumulate evidence that investigates a naming speed deficit that is independent of a phonological deficit for readers with dyslexia. The existing evidence does not support a persistent core deficit in naming speed for readers with dyslexia.

Evaluation of spray drift using low speed wind tunnel measurements and dispersion modeling

USDA-ARS?s Scientific Manuscript database

The objective of this work was to evaluate the EPA’s proposed Test Plan for the validation testing of pesticide spray drift reduction technologies (DRTs) for row and field crops, focusing on the evaluation of ground application systems using the low-speed wind tunnel protocols and processing the dat...

Visual control of flight speed in Drosophila melanogaster.

PubMed

Fry, Steven N; Rohrseitz, Nicola; Straw, Andrew D; Dickinson, Michael H

2009-04-01

Flight control in insects depends on self-induced image motion (optic flow), which the visual system must process to generate appropriate corrective steering maneuvers. Classic experiments in tethered insects applied rigorous system identification techniques for the analysis of turning reactions in the presence of rotating pattern stimuli delivered in open-loop. However, the functional relevance of these measurements for visual free-flight control remains equivocal due to the largely unknown effects of the highly constrained experimental conditions. To perform a systems analysis of the visual flight speed response under free-flight conditions, we implemented a 'one-parameter open-loop' paradigm using 'TrackFly' in a wind tunnel equipped with real-time tracking and virtual reality display technology. Upwind flying flies were stimulated with sine gratings of varying temporal and spatial frequencies, and the resulting speed responses were measured from the resulting flight speed reactions. To control flight speed, the visual system of the fruit fly extracts linear pattern velocity robustly over a broad range of spatio-temporal frequencies. The speed signal is used for a proportional control of flight speed within locomotor limits. The extraction of pattern velocity over a broad spatio-temporal frequency range may require more sophisticated motion processing mechanisms than those identified in flies so far. In Drosophila, the neuromotor pathways underlying flight speed control may be suitably explored by applying advanced genetic techniques, for which our data can serve as a baseline. Finally, the high-level control principles identified in the fly can be meaningfully transferred into a robotic context, such as for the robust and efficient control of autonomous flying micro air vehicles.

A numerical study of zone-melting process for the thermoelectric material of Bi2Te3

NASA Astrophysics Data System (ADS)

Chen, W. C.; Wu, Y. C.; Hwang, W. S.; Hsieh, H. L.; Huang, J. Y.; Huang, T. K.

2015-06-01

In this study, a numerical model has been established by employing a commercial software; ProCAST, to simulate the variation/distribution of temperature and the subsequent microstructure of Bi2Te3 fabricated by zone-melting technique. Then an experiment is conducted to measure the temperature variation/distribution during the zone-melting process to validate the numerical system. Also, the effects of processing parameters on crystallization microstructure such as moving speed and temperature of heater are numerically evaluated. In the experiment, the Bi2Te3 powder are filled into a 30mm diameter quartz cylinder and the heater is set to 800°C with a moving speed 12.5 mm/hr. A thermocouple is inserted in the Bi2Te3 powder to measure the temperature variation/distribution of the zone-melting process. The temperature variation/distribution measured by experiment is compared to the results of numerical simulation. The results show that our model and the experiment are well matched. Then the model is used to evaluate the crystal formation for Bi2Te3 with a 30mm diameter process. It's found that when the moving speed is slower than 17.5 mm/hr, columnar crystal is obtained. In the end, we use this model to predict the crystal formation of zone-melting process for Bi2Te3 with a 45 mm diameter. The results show that it is difficult to grow columnar crystal when the diameter comes to 45mm.

Development of a Tablet-based symbol digit modalities test for reliably assessing information processing speed in patients with stroke.

PubMed

Tung, Li-Chen; Yu, Wan-Hui; Lin, Gong-Hong; Yu, Tzu-Ying; Wu, Chien-Te; Tsai, Chia-Yin; Chou, Willy; Chen, Mei-Hsiang; Hsieh, Ching-Lin

2016-09-01

To develop a Tablet-based Symbol Digit Modalities Test (T-SDMT) and to examine the test-retest reliability and concurrent validity of the T-SDMT in patients with stroke. The study had two phases. In the first phase, six experts, nine college students and five outpatients participated in the development and testing of the T-SDMT. In the second phase, 52 outpatients were evaluated twice (2 weeks apart) with the T-SDMT and SDMT to examine the test-retest reliability and concurrent validity of the T-SDMT. The T-SDMT was developed via expert input and college student/patient feedback. Regarding test-retest reliability, the practise effects of the T-SDMT and SDMT were both trivial (d=0.12) but significant (p≦0.015). The improvement in the T-SDMT (4.7%) was smaller than that in the SDMT (5.6%). The minimal detectable changes (MDC%) of the T-SDMT and SDMT were 6.7 (22.8%) and 10.3 (32.8%), respectively. The T-SDMT and SDMT were highly correlated with each other at the two time points (Pearson's r=0.90-0.91). The T-SDMT demonstrated good concurrent validity with the SDMT. Because the T-SDMT had a smaller practise effect and less random measurement error (superior test-retest reliability), it is recommended over the SDMT for assessing information processing speed in patients with stroke. Implications for Rehabilitation The Symbol Digit Modalities Test (SDMT), a common measure of information processing speed, showed a substantial practise effect and considerable random measurement error in patients with stroke. The Tablet-based SDMT (T-SDMT) has been developed to reduce the practise effect and random measurement error of the SDMT in patients with stroke. The T-SDMT had smaller practise effect and random measurement error than the SDMT, which can provide more reliable assessments of information processing speed.

Corpus callosum atrophy as a marker of clinically meaningful cognitive decline in secondary progressive multiple sclerosis. Impact on employment status.

PubMed

Papathanasiou, Athanasios; Messinis, Lambros; Zampakis, Petros; Papathanasopoulos, Panagiotis

2017-09-01

Cognitive impairment in Multiple Sclerosis (MS) is more frequent and pronounced in secondary progressive MS (SPMS). Cognitive decline is an important predictor of employment status in patients with MS. Magnetic Resonance Imaging (MRI) markers have been used to associate tissue damage with cognitive dysfunction. The aim of the study was to designate the MRI marker that predicts cognitive decline in SPMS and explore its effect on employment status. 30 SPMS patients and 30 healthy participants underwent neuropsychological assessment using the Trail Making Test (TMT) parts A and B, semantic and phonological verbal fluency task and a computerized cognitive screening battery (Central Nervous System Vital Signs). Employment status was obtained as a quality of life measure. Brain MRI was performed in all participants. We measured total lesion volume, third ventricle width, thalamic and corpus callosum atrophy. The frequency of cognitive decline for our SPMS patients was 80%. SPMS patients differed significantly from controls in all neuropsychological measures. Corpus callosum area was correlated with cognitive flexibility, processing speed, composite memory, executive functions, psychomotor speed, reaction time and phonological verbal fluency task. Processing speed and composite memory were the most sensitive markers for predicting employment status. Corpus callosum area was the most sensitive MRI marker for memory and processing speed. Corpus callosum atrophy predicts a clinically meaningful cognitive decline, affecting employment status in our SPMS patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

FPGA-Based Smart Sensor for Online Displacement Measurements Using a Heterodyne Interferometer

PubMed Central

Vera-Salas, Luis Alberto; Moreno-Tapia, Sandra Veronica; Garcia-Perez, Arturo; de Jesus Romero-Troncoso, Rene; Osornio-Rios, Roque Alfredo; Serroukh, Ibrahim; Cabal-Yepez, Eduardo

2011-01-01

The measurement of small displacements on the nanometric scale demands metrological systems of high accuracy and precision. In this context, interferometer-based displacement measurements have become the main tools used for traceable dimensional metrology. The different industrial applications in which small displacement measurements are employed requires the use of online measurements, high speed processes, open architecture control systems, as well as good adaptability to specific process conditions. The main contribution of this work is the development of a smart sensor for large displacement measurement based on phase measurement which achieves high accuracy and resolution, designed to be used with a commercial heterodyne interferometer. The system is based on a low-cost Field Programmable Gate Array (FPGA) allowing the integration of several functions in a single portable device. This system is optimal for high speed applications where online measurement is needed and the reconfigurability feature allows the addition of different modules for error compensation, as might be required by a specific application. PMID:22164040

The tactile motion aftereffect suggests an intensive code for speed in neurons sensitive to both speed and direction of motion

PubMed Central

Birznieks, I.; Vickery, R. M.; Holcombe, A. O.; Seizova-Cajic, T.

2016-01-01

Neurophysiological studies in primates have found that direction-sensitive neurons in the primary somatosensory cortex (SI) generally increase their response rate with increasing speed of object motion across the skin and show little evidence of speed tuning. We employed psychophysics to determine whether human perception of motion direction could be explained by features of such neurons and whether evidence can be found for a speed-tuned process. After adaptation to motion across the skin, a subsequently presented dynamic test stimulus yields an impression of motion in the opposite direction. We measured the strength of this tactile motion aftereffect (tMAE) induced with different combinations of adapting and test speeds. Distal-to-proximal or proximal-to-distal adapting motion was applied to participants' index fingers using a tactile array, after which participants reported the perceived direction of a bidirectional test stimulus. An intensive code for speed, like that observed in SI neurons, predicts greater adaptation (and a stronger tMAE) the faster the adapting speed, regardless of the test speed. In contrast, speed tuning of direction-sensitive neurons predicts the greatest tMAE when the adapting and test stimuli have matching speeds. We found that the strength of the tMAE increased monotonically with adapting speed, regardless of the test speed, showing no evidence of speed tuning. Our data are consistent with neurophysiological findings that suggest an intensive code for speed along the motion processing pathways comprising neurons sensitive both to speed and direction of motion. PMID:26823511

The Utility of the Supine-to-Stand Test as a Measure of Functional Motor Competence in Children Aged 5–9 Years

PubMed Central

Duncan, Michael J.; Lawson, Chelsey; Walker, Leanne Jaye; Stodden, David; Eyre, Emma L. J.

2017-01-01

This study examined how supine-to-stand (STS) performance is related to process and product assessment of motor competence (MC) in children. Ninety-one children aged 5–9 years were assessed for process and product MC (10 m running speed and standing long jump) as well as process and product measures of STS. Tertiles were created for STS process and STS product scores to create 3 groups reflecting low, medium, and high STS competency. ANCOVA analysis, controlling for age, for process STS, indicated that process MC was significantly higher in children, classified as medium STS (p = 0.048) and high STS (p = 0.011) competence, and that 10 m run speed was slower for low STS compared to medium (p = 0.019) and high STS (p = 0.004). For product STS tertiles, process MC was significantly higher for children in the lowest (fastest) STS tertile compared to those in the medium highest (slowest) tertile (p = 0.01). PMID:29910427

Brief report: Response inhibition and processing speed in children with motor difficulties and developmental coordination disorder.

PubMed

Bernardi, Marialivia; Leonard, Hayley C; Hill, Elisabeth L; Henry, Lucy A

2016-01-01

A previous study reported that children with poor motor skills, classified as having motor difficulties (MD) or Developmental Coordination Disorder (DCD), produced more errors in a motor response inhibition task compared to typically developing (TD) children but did not differ in verbal inhibition errors. The present study investigated whether these groups differed in the length of time they took to respond in order to achieve these levels of accuracy, and whether any differences in response speed could be explained by generally slow information processing in children with poor motor skills. Timing data from the Verbal Inhibition Motor Inhibition test were analyzed to identify differences in performance between the groups on verbal and motor inhibition, as well as on processing speed measures from standardized batteries. Although children with MD and DCD produced more errors in the motor inhibition task than TD children, the current analyses found that they did not take longer to complete the task. Children with DCD were slower at inhibiting verbal responses than TD children, while the MD group seemed to perform at an intermediate level between the other groups in terms of verbal inhibition speed. Slow processing speed did not account for these group differences. Results extended previous research into response inhibition in children with poor motor skills by explicitly comparing motor and verbal responses, and suggesting that slow performance, even when accurate, may be attributable to an inefficient way of inhibiting responses, rather than slow information processing speed per se.

The Application of Virtex-II Pro FPGA in High-Speed Image Processing Technology of Robot Vision Sensor

NASA Astrophysics Data System (ADS)

Ren, Y. J.; Zhu, J. G.; Yang, X. Y.; Ye, S. H.

2006-10-01

The Virtex-II Pro FPGA is applied to the vision sensor tracking system of IRB2400 robot. The hardware platform, which undertakes the task of improving SNR and compressing data, is constructed by using the high-speed image processing of FPGA. The lower level image-processing algorithm is realized by combining the FPGA frame and the embedded CPU. The velocity of image processing is accelerated due to the introduction of FPGA and CPU. The usage of the embedded CPU makes it easily to realize the logic design of interface. Some key techniques are presented in the text, such as read-write process, template matching, convolution, and some modules are simulated too. In the end, the compare among the modules using this design, using the PC computer and using the DSP, is carried out. Because the high-speed image processing system core is a chip of FPGA, the function of which can renew conveniently, therefore, to a degree, the measure system is intelligent.

Modeling and Analysis of CNC Milling Process Parameters on Al3030 based Composite

NASA Astrophysics Data System (ADS)

Gupta, Anand; Soni, P. K.; Krishna, C. M.

2018-04-01

The machining of Al3030 based composites on Computer Numerical Control (CNC) high speed milling machine have assumed importance because of their wide application in aerospace industries, marine industries and automotive industries etc. Industries mainly focus on surface irregularities; material removal rate (MRR) and tool wear rate (TWR) which usually depends on input process parameters namely cutting speed, feed in mm/min, depth of cut and step over ratio. Many researchers have carried out researches in this area but very few have taken step over ratio or radial depth of cut also as one of the input variables. In this research work, the study of characteristics of Al3030 is carried out at high speed CNC milling machine over the speed range of 3000 to 5000 r.p.m. Step over ratio, depth of cut and feed rate are other input variables taken into consideration in this research work. A total nine experiments are conducted according to Taguchi L9 orthogonal array. The machining is carried out on high speed CNC milling machine using flat end mill of diameter 10mm. Flatness, MRR and TWR are taken as output parameters. Flatness has been measured using portable Coordinate Measuring Machine (CMM). Linear regression models have been developed using Minitab 18 software and result are validated by conducting selected additional set of experiments. Selection of input process parameters in order to get best machining outputs is the key contributions of this research work.

Frequency domain laser velocimeter signal processor: A new signal processing scheme

NASA Technical Reports Server (NTRS)

Meyers, James F.; Clemmons, James I., Jr.

1987-01-01

A new scheme for processing signals from laser velocimeter systems is described. The technique utilizes the capabilities of advanced digital electronics to yield a smart instrument that is able to configure itself, based on the characteristics of the input signals, for optimum measurement accuracy. The signal processor is composed of a high-speed 2-bit transient recorder for signal capture and a combination of adaptive digital filters with energy and/or zero crossing detection signal processing. The system is designed to accept signals with frequencies up to 100 MHz with standard deviations up to 20 percent of the average signal frequency. Results from comparative simulation studies indicate measurement accuracies 2.5 times better than with a high-speed burst counter, from signals with as few as 150 photons per burst.

Education is associated with higher later life IQ scores, but not with faster cognitive processing speed.

PubMed

Ritchie, Stuart J; Bates, Timothy C; Der, Geoff; Starr, John M; Deary, Ian J

2013-06-01

Recent reports suggest a causal relationship between education and IQ, which has implications for cognitive development and aging-education may improve cognitive reserve. In two longitudinal cohorts, we tested the association between education and lifetime cognitive change. We then tested whether education is linked to improved scores on processing-speed variables such as reaction time, which are associated with both IQ and longevity. Controlling for childhood IQ score, we found that education was positively associated with IQ at ages 79 (Sample 1) and 70 (Sample 2), and more strongly for participants with lower initial IQ scores. Education, however, showed no significant association with processing speed, measured at ages 83 and 70. Increased education may enhance important later life cognitive capacities, but does not appear to improve more fundamental aspects of cognitive processing. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Clinical utility of the Wechsler Adult Intelligence Scale-Fourth Edition after traumatic brain injury.

PubMed

Donders, Jacobus; Strong, Carrie-Ann H

2015-02-01

The performance of 100 patients with traumatic brain injury (TBI) on the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) was compared with that of 100 demographically matched neurologically healthy controls. Processing Speed was the only WAIS-IV factor index that was able to discriminate between persons with moderate-severe TBI on the one hand and persons with either less severe TBI or neurologically healthy controls on the other hand. The Processing Speed index also had acceptable sensitivity and specificity when differentiating between patients with TBI who either did or did not have scores in the clinically significant range on the Trail Making Test. It is concluded that WAIS-IV Processing Speed has acceptable clinical utility in the evaluation of patients with moderate-severe TBI but that it should be supplemented with other measures to assure sufficient accuracy in the diagnostic process. © The Author(s) 2014.

Criterion validity of the Wechsler Intelligence Scale for Children-Fourth Edition after pediatric traumatic brain injury.

PubMed

Donders, Jacobus; Janke, Kelly

2008-07-01

The performance of 40 children with complicated mild to severe traumatic brain injury on the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV; Wechsler, 2003) was compared with that of 40 demographically matched healthy controls. Of the four WISC-IV factor index scores, only Processing Speed yielded a statistically significant group difference (p < .001) as well as a statistically significant negative correlation with length of coma (p < .01). Logistic regression, using Processing Speed to classify individual children, yielded a sensitivity of 72.50% and a specificity of 62.50%, with false positive and false negative rates both exceeding 30%. We conclude that Processing Speed has acceptable criterion validity in the evaluation of children with complicated mild to severe traumatic brain injury but that the WISC-IV should be supplemented with other measures to assure sufficient accuracy in the diagnostic process.

A Comparison of Crater-Size Scaling and Ejection-Speed Scaling During Experimental Impacts in Sand

NASA Technical Reports Server (NTRS)

Anderson, J. L. B.; Cintala, M. J.; Johnson, M. K.

2014-01-01

Non-dimensional scaling relationships are used to understand various cratering processes including final crater sizes and the excavation of material from a growing crater. The principal assumption behind these scaling relationships is that these processes depend on a combination of the projectile's characteristics, namely its diameter, density, and impact speed. This simplifies the impact event into a single point-source. So long as the process of interest is beyond a few projectile radii from the impact point, the point-source assumption holds. These assumptions can be tested through laboratory experiments in which the initial conditions of the impact are controlled and resulting processes measured directly. In this contribution, we continue our exploration of the congruence between crater-size scaling and ejection-speed scaling relationships. In particular, we examine a series of experimental suites in which the projectile diameter and average grain size of the target are varied.

Does participation in art classes influence performance on two different cognitive tasks?

PubMed

Schindler, Manuel; Maihöfner, Christian; Bolwerk, Anne; Lang, Frieder R

2017-04-01

Effects of two mentally stimulating art interventions on processing speed and visuo-spatial cognition were compared in three samples. In a randomized 10-week art intervention study with a pre-post follow-up design, 113 adults (27 healthy older adults with subjective memory complaints, 50 healthy older adults and 36 healthy younger adults) were randomly assigned to one of two groups: visual art production or cognitive art evaluation, where the participants either produced or evaluated art. ANOVAs with repeated measures were computed to observe effects on the Symbol-Digit Test, and the Stick Test. Significant Time effects were found with regard to processing speed and visuo-spatial cognition. Additionally, there was found a significant Time × Sample interaction for processing speed. The effects proved robust after testing for education and adding sex as additional factor. Mental stimulation by participation in art classes leads to an improvement of processing speed and visuo-spatial cognition. Further investigation is required to improve understanding of the potential impact of art intervention on cognitive abilities across adulthood.

A novel vibration-based fault diagnostic algorithm for gearboxes under speed fluctuations without rotational speed measurement

NASA Astrophysics Data System (ADS)

Hong, Liu; Qu, Yongzhi; Dhupia, Jaspreet Singh; Sheng, Shuangwen; Tan, Yuegang; Zhou, Zude

2017-09-01

The localized failures of gears introduce cyclic-transient impulses in the measured gearbox vibration signals. These impulses are usually identified from the sidebands around gear-mesh harmonics through the spectral analysis of cyclo-stationary signals. However, in practice, several high-powered applications of gearboxes like wind turbines are intrinsically characterized by nonstationary processes that blur the measured vibration spectra of a gearbox and deteriorate the efficacy of spectral diagnostic methods. Although order-tracking techniques have been proposed to improve the performance of spectral diagnosis for nonstationary signals measured in such applications, the required hardware for the measurement of rotational speed of these machines is often unavailable in industrial settings. Moreover, existing tacho-less order-tracking approaches are usually limited by the high time-frequency resolution requirement, which is a prerequisite for the precise estimation of the instantaneous frequency. To address such issues, a novel fault-signature enhancement algorithm is proposed that can alleviate the spectral smearing without the need of rotational speed measurement. This proposed tacho-less diagnostic technique resamples the measured acceleration signal of the gearbox based on the optimal warping path evaluated from the fast dynamic time-warping algorithm, which aligns a filtered shaft rotational harmonic signal with respect to a reference signal assuming a constant shaft rotational speed estimated from the approximation of operational speed. The effectiveness of this method is validated using both simulated signals from a fixed-axis gear pair under nonstationary conditions and experimental measurements from a 750-kW planetary wind turbine gearbox on a dynamometer test rig. The results demonstrate that the proposed algorithm can identify fault information from typical gearbox vibration measurements carried out in a resource-constrained industrial environment.

A novel vibration-based fault diagnostic algorithm for gearboxes under speed fluctuations without rotational speed measurement

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

Hong, Liu; Qu, Yongzhi; Dhupia, Jaspreet Singh

The localized failures of gears introduce cyclic-transient impulses in the measured gearbox vibration signals. These impulses are usually identified from the sidebands around gear-mesh harmonics through the spectral analysis of cyclo-stationary signals. However, in practice, several high-powered applications of gearboxes like wind turbines are intrinsically characterized by nonstationary processes that blur the measured vibration spectra of a gearbox and deteriorate the efficacy of spectral diagnostic methods. Although order-tracking techniques have been proposed to improve the performance of spectral diagnosis for nonstationary signals measured in such applications, the required hardware for the measurement of rotational speed of these machines is oftenmore » unavailable in industrial settings. Moreover, existing tacho-less order-tracking approaches are usually limited by the high time-frequency resolution requirement, which is a prerequisite for the precise estimation of the instantaneous frequency. To address such issues, a novel fault-signature enhancement algorithm is proposed that can alleviate the spectral smearing without the need of rotational speed measurement. This proposed tacho-less diagnostic technique resamples the measured acceleration signal of the gearbox based on the optimal warping path evaluated from the fast dynamic time-warping algorithm, which aligns a filtered shaft rotational harmonic signal with respect to a reference signal assuming a constant shaft rotational speed estimated from the approximation of operational speed. The effectiveness of this method is validated using both simulated signals from a fixed-axis gear pair under nonstationary conditions and experimental measurements from a 750-kW planetary wind turbine gearbox on a dynamometer test rig. Lastly, the results demonstrate that the proposed algorithm can identify fault information from typical gearbox vibration measurements carried out in a resource-constrained industrial environment.« less

A novel vibration-based fault diagnostic algorithm for gearboxes under speed fluctuations without rotational speed measurement

DOE PAGES

Hong, Liu; Qu, Yongzhi; Dhupia, Jaspreet Singh; ...

2017-02-27

The localized failures of gears introduce cyclic-transient impulses in the measured gearbox vibration signals. These impulses are usually identified from the sidebands around gear-mesh harmonics through the spectral analysis of cyclo-stationary signals. However, in practice, several high-powered applications of gearboxes like wind turbines are intrinsically characterized by nonstationary processes that blur the measured vibration spectra of a gearbox and deteriorate the efficacy of spectral diagnostic methods. Although order-tracking techniques have been proposed to improve the performance of spectral diagnosis for nonstationary signals measured in such applications, the required hardware for the measurement of rotational speed of these machines is oftenmore » unavailable in industrial settings. Moreover, existing tacho-less order-tracking approaches are usually limited by the high time-frequency resolution requirement, which is a prerequisite for the precise estimation of the instantaneous frequency. To address such issues, a novel fault-signature enhancement algorithm is proposed that can alleviate the spectral smearing without the need of rotational speed measurement. This proposed tacho-less diagnostic technique resamples the measured acceleration signal of the gearbox based on the optimal warping path evaluated from the fast dynamic time-warping algorithm, which aligns a filtered shaft rotational harmonic signal with respect to a reference signal assuming a constant shaft rotational speed estimated from the approximation of operational speed. The effectiveness of this method is validated using both simulated signals from a fixed-axis gear pair under nonstationary conditions and experimental measurements from a 750-kW planetary wind turbine gearbox on a dynamometer test rig. Lastly, the results demonstrate that the proposed algorithm can identify fault information from typical gearbox vibration measurements carried out in a resource-constrained industrial environment.« less

Longitudinal Mediation of Processing Speed on Age-Related Change in Memory and Fluid Intelligence

PubMed Central

Robitaille, Annie; Piccinin, Andrea M.; Muniz, Graciela; Hoffman, Lesa; Johansson, Boo; Deeg, Dorly J.H.; Aartsen, Marja J.; Comijs, Hannie C.; Hofer, Scott M.

2014-01-01

Age-related decline in processing speed has long been considered a key driver of cognitive aging. While the majority of empirical evidence for the processing speed hypothesis has been obtained from analyses of between-person age differences, longitudinal studies provide a direct test of within-person change. Using recent developments in longitudinal mediation analysis, we examine the speed–mediation hypothesis at both the within- and between-person levels in two longitudinal studies, LASA and OCTO-Twin. We found significant within-person indirect effects of change in age, such that increasing age was related to lower speed which, in turn, relates to lower performance across repeated measures on other cognitive outcomes. Although between-person indirect effects were also significant in LASA, they were not in OCTO-Twin. These differing magnitudes of direct and indirect effects across levels demonstrate the importance of separating between- and within-person effects in evaluating theoretical models of age-related change. PMID:23957224

Coupled changes in brain white matter microstructure and fluid intelligence in later life.

PubMed

Ritchie, Stuart J; Bastin, Mark E; Tucker-Drob, Elliot M; Maniega, Susana Muñoz; Engelhardt, Laura E; Cox, Simon R; Royle, Natalie A; Gow, Alan J; Corley, Janie; Pattie, Alison; Taylor, Adele M; Valdés Hernández, Maria Del C; Starr, John M; Wardlaw, Joanna M; Deary, Ian J

2015-06-03

Understanding aging-related cognitive decline is of growing importance in aging societies, but relatively little is known about its neural substrates. Measures of white matter microstructure are known to correlate cross-sectionally with cognitive ability measures, but only a few small studies have tested for longitudinal relations among these variables. We tested whether there were coupled changes in brain white matter microstructure indexed by fractional anisotropy (FA) and three broad cognitive domains (fluid intelligence, processing speed, and memory) in a large cohort of human participants with longitudinal diffusion tensor MRI and detailed cognitive data taken at ages 73 years (n = 731) and 76 years (n = 488). Longitudinal changes in white matter microstructure were coupled with changes in fluid intelligence, but not with processing speed or memory. Individuals with higher baseline white matter FA showed less subsequent decline in processing speed. Our results provide evidence for a longitudinal link between changes in white matter microstructure and aging-related cognitive decline during the eighth decade of life. They are consistent with theoretical perspectives positing that a corticocortical "disconnection" partly explains cognitive aging. Copyright © 2015 Ritchie et al.

Validation of the AQT Color-Form Additive Model for Screening and Monitoring Pharmacological Treatment of ADHD

ERIC Educational Resources Information Center

Nielsen, Niels Peter; Wiig, Elisabeth Hemmersam

2013-01-01

Objective:This retrospective study used A Quick Test of Cognitive Speed (AQT) processing-speed and efficiency measures for evaluating sensitivity and monitoring effects during pharmacological treatment of adults with ADHD. Method: Color (C), form (F), and color-form (CF) combination naming were administered to 69 adults during outpatient…

Speed discrimination predicts word but not pseudo-word reading rate in adults and children

PubMed Central

Main, Keith L.; Pestilli, Franco; Mezer, Aviv; Yeatman, Jason; Martin, Ryan; Phipps, Stephanie; Wandell, Brian

2014-01-01

Word familiarity may affect magnocellular processes of word recognition. To explore this idea, we measured reading rate, speed-discrimination, and contrast detection thresholds in adults and children with a wide range of reading abilities. We found that speed-discrimination thresholds are higher in children than in adults and are correlated with age. Speed discrimination thresholds are also correlated with reading rate, but only for words, not for pseudo-words. Conversely, we found no correlation between contrast sensitivity and reading rate and no correlation between speed discrimination thresholds WASI subtest scores. These findings support the position that reading rate is influenced by magnocellular circuitry attuned to the recognition of familiar word-forms. PMID:25278418

Eye-Tracking Measurements of Language Processing: Developmental Differences in Children at High Risk for ASD

ERIC Educational Resources Information Center

Chita-Tegmark, Meia; Arunachalam, Sudha; Nelson, Charles A.; Tager-Flusberg, Helen

2015-01-01

To explore how being at high risk for autism spectrum disorder (ASD), based on having an older sibling diagnosed with ASD, affects word comprehension and language processing speed, 18-, 24- and 36-month-old children, at high and low risk for ASD were tested in a cross-sectional study, on an eye gaze measure of receptive language that measured how…

Tablet Velocity Measurement and Prediction in the Pharmaceutical Film Coating Process.

PubMed

Suzuki, Yasuhiro; Yokohama, Chihiro; Minami, Hidemi; Terada, Katsuhide

2016-01-01

The purpose of this study was to measure the tablet velocity in pan coating machines during the film coating process in order to understand the impact of the batch size (laboratory to commercial scale), coating machine type (DRIACOATER, HICOATER® and AQUA COATER®) and manufacturing conditions on tablet velocity. We used a high speed camera and particle image velocimetry to measure the tablet velocity in the coating pans. It was observed that increasing batch sizes resulted in increased tablet velocities under the same rotation number because of the differences in circumferential rotation speeds. We also observed the tendency that increase in the filling ratio of tablets resulted in an increased tablet velocity for all coating machines. Statistical analysis was used to make a tablet velocity predictive equation by employing the filling ratio and rotation speed as the parameters from these measured values. The correlation coefficients of predicted value and experimental value were more than 0.959 in each machine. Using the predictive equation to determine tablet velocities, the manufacturing conditions of previous products were reviewed, and it was found that the tablet velocities of commercial scales, in which tablet chipping and breakage problems had occurred, were higher than those of pilot scales or laboratory scales.

Synchronous high speed multi-point velocity profile measurement by heterodyne interferometry

NASA Astrophysics Data System (ADS)

Hou, Xueqin; Xiao, Wen; Chen, Zonghui; Qin, Xiaodong; Pan, Feng

2017-02-01

This paper presents a synchronous multipoint velocity profile measurement system, which acquires the vibration velocities as well as images of vibrating objects by combining optical heterodyne interferometry and a high-speed CMOS-DVR camera. The high-speed CMOS-DVR camera records a sequence of images of the vibrating object. Then, by extracting and processing multiple pixels at the same time, a digital demodulation technique is implemented to simultaneously acquire the vibrating velocity of the target from the recorded sequences of images. This method is validated with an experiment. A piezoelectric ceramic plate with standard vibration characteristics is used as the vibrating target, which is driven by a standard sinusoidal signal.

Do the same factors predict outcome in schizophrenia and non-schizophrenia syndromes after first-episode psychosis? A two-year follow-up study.

PubMed

Peña, Javier; Segarra, Rafael; Ojeda, Natalia; García, Jon; Eguiluz, José I; Gutiérrez, Miguel

2012-06-01

The aim of this two-year longitudinal study was to identify the best baseline predictors of functional outcome in first-episode psychosis (FEP). We tested whether the same factors predict functional outcomes in two different subsamples of FEP patients: schizophrenia and non-schizophrenia syndrome groups. Ninety-five patients with FEP underwent a full clinical evaluation (i.e., PANSS, Mania, Depression and Insight). Functional outcome measurements included the WHO Disability Assessment Schedule (DAS-WHO), Global Assessment of Functioning (GAF) and Clinical Global Impression (CGI). Estimation of cognition was obtained by a neuropsychological battery which included attention, processing speed, language, memory and executive functioning. Greater severity of visuospatial functioning at baseline predicted poorer functional outcome as measured by the three functional scales (GAF, CGI and DAS-WHO) in the pooled FEP sample (explaining ut to the 12%, 9% and 10% of the variance, respectively). Negative symptoms also effectively contributed to predict GAF scores (8%). However, we obtained different predictive values after differentiating sample diagnoses. Processing speed significantly predicted most functional outcome measures in patients with schizophrenia, whereas visuospatial functioning was the only significant predictor of functional outcomes in the non-schizophrenia subgroup. Our results suggest that processing speed, visuospatial functioning and negative symptoms significantly (but differentially) predict outcomes in patients with FEP, depending on their clinical progression. For patients without a schizophrenia diagnosis, visuospatial functioning was the best predictor of functional outcome. The performance on processing speed seemed to be a key factor in more severe syndromes. However, only a small proportion of the variance could be explained by the model, so there must be many other factors that have to be considered. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cognitive Function in Normal-Weight, Overweight, and Obese Older Adults: An Analysis of the Advanced Cognitive Training for Independent and Vital Elderly Cohort

PubMed Central

Kuo, Hsu-Ko; Jones, Richard N.; Milberg, William P.; Tennstedt, Sharon; Talbot, Laura; Morris, John N.; Lipsitz, Lewis A.

2010-01-01

OBJECTIVES To assess how elevated body mass index (BMI) affects cognitive function in elderly people. DESIGN Cross-sectional study. SETTING Data for this cross-sectional study were taken from a multicenter randomized controlled trial, the Advanced Cognitive Training for Independent and Vital Elderly trial. PARTICIPANTS The analytic sample included 2,684 normal-weight, overweight, or obese subjects aged 65 to 94. MEASUREMENTS Evaluation of cognitive abilities was performed in several domains: global cognition, memory, reasoning, and speed of processing. Cross-sectional association between body weight status and cognitive functions was analyzed using multiple linear regression. RESULTS Overweight subjects had better performance on a reasoning task (β = 0.23, standard error (SE) = 0.11, P = .04) and the Useful Field of View (UFOV) measure (β = −39.46, SE = 12.95, P = .002), a test of visuospatial speed of processing, after controlling for age, sex, race, years of education, intervention group, study site, and cardiovascular risk factors. Subjects with class I (BMI 30.0–34.9 kg/m2) and class II (BMI>35.0 kg/m2) obesity had better UFOV measure scores (β = −38.98, SE = 14.77, P = .008; β = −35.75, SE = 17.65, and P = .04, respectively) in the multivariate model than normal-weight subjects. The relationships between BMI and individual cognitive domains were nonlinear. CONCLUSION Overweight participants had better cognitive performance in terms of reasoning and visuospatial speed of processing than normal-weight participants. Obesity was associated with better performance in visuospatial speed of processing than normal weight. The relationship between BMI and cognitive function should be studied prospectively. PMID:16420204

In situ flash x-ray high-speed computed tomography for the quantitative analysis of highly dynamic processes

NASA Astrophysics Data System (ADS)

Moser, Stefan; Nau, Siegfried; Salk, Manfred; Thoma, Klaus

2014-02-01

The in situ investigation of dynamic events, ranging from car crash to ballistics, often is key to the understanding of dynamic material behavior. In many cases the important processes and interactions happen on the scale of milli- to microseconds at speeds of 1000 m s-1 or more. Often, 3D information is necessary to fully capture and analyze all relevant effects. High-speed 3D-visualization techniques are thus required for the in situ analysis. 3D-capable optical high-speed methods often are impaired by luminous effects and dust, while flash x-ray based methods usually deliver only 2D data. In this paper, a novel 3D-capable flash x-ray based method, in situ flash x-ray high-speed computed tomography is presented. The method is capable of producing 3D reconstructions of high-speed processes based on an undersampled dataset consisting of only a few (typically 3 to 6) x-ray projections. The major challenges are identified, discussed and the chosen solution outlined. The application is illustrated with an exemplary application of a 1000 m s-1 high-speed impact event on the scale of microseconds. A quantitative analysis of the in situ measurement of the material fragments with a 3D reconstruction with 1 mm voxel size is presented and the results are discussed. The results show that the HSCT method allows gaining valuable visual and quantitative mechanical information for the understanding and interpretation of high-speed events.

Real-time 3D measurement based on structured light illumination considering camera lens distortion

NASA Astrophysics Data System (ADS)

Feng, Shijie; Chen, Qian; Zuo, Chao; Sun, Jiasong; Yu, ShiLing

2014-12-01

Optical three-dimensional (3-D) profilometry is gaining increasing attention for its simplicity, flexibility, high accuracy, and non-contact nature. Recent advances in imaging sensors and digital projection technology further its progress in high-speed, real-time applications, enabling 3-D shapes reconstruction of moving objects and dynamic scenes. In traditional 3-D measurement system where the processing time is not a key factor, camera lens distortion correction is performed directly. However, for the time-critical high-speed applications, the time-consuming correction algorithm is inappropriate to be performed directly during the real-time process. To cope with this issue, here we present a novel high-speed real-time 3-D coordinates measuring technique based on fringe projection with the consideration of the camera lens distortion. A pixel mapping relation between a distorted image and a corrected one is pre-determined and stored in computer memory for real-time fringe correction. And a method of lookup table (LUT) is introduced as well for fast data processing. Our experimental results reveal that the measurement error of the in-plane coordinates has been reduced by one order of magnitude and the accuracy of the out-plane coordinate been tripled after the distortions being eliminated. Moreover, owing to the merit of the LUT, the 3-D reconstruction can be achieved at 92.34 frames per second.

Fragmentation Speed at Magmatic Temperatures: an Experimental Determination

NASA Astrophysics Data System (ADS)

Alatorre-Ibarguengoitia, M. A.; Scheu, B.; Dingwell, D. B.

2011-12-01

The propagation speed of the fragmentation front (fragmentation speed) is a controlling factor in the dynamics of explosive volcanic eruptions and can affect the eruptive regime. It is impossible to measure the fragmentation speed directly in natural systems. Thus, laboratory experiments using natural samples represent a unique source of information revealing the dynamics of fragmentation processes. Rapid decompression experiments of natural samples from several volcanoes allowed us to quantify the influence of sample porosity and pressure differential on the fragmentation speed. These previous experiments have been performed almost exclusively at temperatures up to 300 °C. Due to experimental constraints it is not possible to measure directly the fragmentation speed at magmatic temperatures using the same procedure as in the experiments up to moderate temperature. The magmatic temperature for the analyzed rock types varies typically between 700 - 900 °C, reflecting their moderate to high silica content. For this reason, the influence of the temperature on the fragmentation speed had not been investigated systematically. In order to determine the fragmentation speed at magmatic temperatures (700 - 900 °C), we performed rapid decompression experiments of volcanic rocks and measured with a high-speed camera the ejection speed at the front of the gas-particle mixture produced by fragmentation. Then we used a theoretical model based on a 1-D shock-tube theory considering the conservation laws across the fragmentation front that provides a relationship between the fragmentation speed and the ejection speed at the front of the gas-particle mixture. This model has been validated in fragmentation experiments at room temperature where the fragmentation and ejection speed were measured simultaneously. We investigated natural volcanic samples covering a broad range of connected porosity (16 - 65 vol. %) and applied pressures (4-20 MPa) at room temperature and up to 850 °C. To our knowledge, this is the first systematic investigation of the fragmentation speed of volcanic samples at magmatic temperatures. These results enhance our understanding of explosive volcanic eruptions. As has been shown by recent studies, a quantitative knowledge of the dynamics of magma fragmentation is critical for determining the eruptive regime.

Non-invasive In vivo measurement of the shear modulus of human vocal fold tissue

PubMed Central

Kazemirad, Siavash; Bakhshaee, Hani; Mongeau, Luc; Kost, Karen

2014-01-01

Voice is the essential part of singing and speech communication. Voice disorders significantly affect the quality of life. The viscoelastic mechanical properties of the vocal fold mucosa determine the characteristics of the vocal folds oscillations, and thereby voice quality. In the present study, a non-invasive method was developed to determine the shear modulus of human vocal fold tissue in vivo via measurements of the mucosal wave propagation speed during phonation. Images of four human subjects’ vocal folds were captured using high speed digital imaging (HSDI) and magnetic resonance imaging (MRI) for different phonation pitches, specifically fundamental frequencies between 110 to 440 Hz. The MRI images were used to obtain the morphometric dimensions of each subject's vocal folds in order to determine the pixel size in the high-speed images. The mucosal wave propagation speed was determined for each subject and at each pitch value using an automated image processing algorithm. The transverse shear modulus of the vocal fold mucosa was then calculated from a surface (Rayleigh) wave propagation dispersion equation using the measured wave speeds. It was found that the mucosal wave propagation speed and therefore the shear modulus of the vocal fold tissue were generally greater at higher pitches. The results were in good agreement with those from other studies obtained via in vitro measurements, thereby supporting the validity of the proposed measurement method. This method offers the potential for in vivo clinical assessments of vocal folds viscoelasticity from HSDI. PMID:24433668

Training attentional control in older adults

PubMed Central

MacKay-Brandt, Anna

2013-01-01

Recent research has demonstrated benefits for older adults from training attentional control using a variable priority strategy, but the construct validity of the training task and the degree to which benefits of training transfer to other contexts are unclear. The goal of this study was to characterize baseline performance on the training task in a sample of 105 healthy older adults and to test for transfer of training in a subset (n = 21). Training gains after 5 days and extent of transfer was compared to another subset (n = 20) that served as a control group. Baseline performance on the training task was characterized by a two-factor model of working memory and processing speed. Processing speed correlated with the training task. Training gains in speed and accuracy were reliable and robust (ps <.001, η2 = .57 to .90). Transfer to an analogous task was observed (ps <.05, η2 = .10 to .17). The beneficial effect of training did not translate to improved performance on related measures of processing speed. This study highlights the robust effect of training and transfer to a similar context using a variable priority training task. Although processing speed is an important aspect of the training task, training benefit is either related to an untested aspect of the training task or transfer of training is limited to the training context. PMID:21728889

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.

N400 Event-Related Potential and Standardized Measures of Reading in Late Elementary School Children: Correlated or Independent?

ERIC Educational Resources Information Center

Coch, Donna; Benoit, Clarisse

2015-01-01

We investigated whether and how standardized behavioral measures of reading and electrophysiological measures of reading were related in 72 typically developing, late elementary school children. Behavioral measures included standardized tests of spelling, phonological processing, vocabulary, comprehension, naming speed, and memory.…

Training working memory in older adults: Is there an advantage of using strategies?

PubMed

Borella, Erika; Carretti, Barbara; Sciore, Roberta; Capotosto, Emanuela; Taconnat, Laurence; Cornoldi, Cesare; De Beni, Rossana

2017-03-01

The purpose of the present study was to test the efficacy of a working memory (WM) training in elderly people, and to compare the effects of a WM training based on an adaptive procedure with one combining the same procedure with the use of a strategy, based on the construction of visual mental images. Eighteen older adults received training with a WM task (the WM group), another 18 received the same WM training and were also taught to use a visual imagery strategy (the WM + Strategy group), and another 18 served as active controls. Training-related gains in the WM (criterion) task and transfer effects on measures of verbal and visuospatial WM, short-term memory (STM), processing speed, and reasoning were considered. Training gains and transfer effects were also assessed after 6 months. After the training, both the trained groups performed better than the control group in the WM criterion task, and maintained these gains 6 months later; they also showed immediate transfer effects on processing speed. The two trained groups also outperformed the control group in the long term in the WM tasks, in one of the STM tasks (backward span task), and in the processing speed measure. Long-term large effect sizes were found for all the tasks involving memory processes in the WM + Strategy group, but only for the processing speed task in the WM group. Findings are discussed in terms of the benefits and limits of teaching older people a strategy in combination with an adaptive WM training. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Analysing the influence of FSP process parameters on IGC susceptibility of AA5083 using Sugeno - Fuzzy model

NASA Astrophysics Data System (ADS)

Jayakarthick, C.; Povendhan, A. P.; Vaira Vignesh, R.; Padmanaban, R.

2018-02-01

Aluminium alloy AA5083 was friction stir processed to improve the intergranular corrosion (IGC) resistance. FSP trials were performed by varying the process parameters as per Taguchi’s L18 orthogonal array. IGC resistance of the friction stir processed specimens were found by immersing them in concentrated nitric acid and measuring the mass loss per unit area. Results indicate that dispersion and partial dissolution of secondary phase increased IGC resistance of the friction stir processed specimens. A Sugeno fuzzy model was developed to study the effect of FSP process parameters on the IGC susceptibility of friction stir processed specimens. Tool Rotation Speed, Tool Traverse Speed and Shoulder Diameter have a significant effect on the IGC susceptibility of the friction stir processed specimens.

A high performance sensor for triaxial cutting force measurement in turning.

PubMed

Zhao, You; Zhao, Yulong; Liang, Songbo; Zhou, Guanwu

2015-04-03

This paper presents a high performance triaxial cutting force sensor with excellent accuracy, favorable natural frequency and acceptable cross-interference for high speed turning process. Octagonal ring is selected as sensitive element of the designed sensor, which is drawn inspiration from ring theory. A novel structure of two mutual-perpendicular octagonal rings is proposed and three Wheatstone full bridge circuits are specially organized in order to obtain triaxial cutting force components and restrain cross-interference. Firstly, the newly developed sensor is tested in static calibration; test results indicate that the sensor possesses outstanding accuracy in the range of 0.38%-0.83%. Secondly, impacting modal tests are conducted to identify the natural frequencies of the sensor in triaxial directions (i.e., 1147 Hz, 1122 Hz and 2035 Hz), which implies that the devised sensor can be used for cutting force measurement in a high speed lathe when the spindle speed does not exceed 17,205 rev/min in continuous cutting condition. Finally, an application of the sensor in turning process is operated to show its performance for real-time cutting force measurement; the measured cutting forces demonstrate a good accordance with the variation of cutting parameters. Thus, the developed sensor possesses perfect properties and it gains great potential for real-time cutting force measurement in turning.

A High Performance Sensor for Triaxial Cutting Force Measurement in Turning

PubMed Central

Zhao, You; Zhao, Yulong; Liang, Songbo; Zhou, Guanwu

2015-01-01

This paper presents a high performance triaxial cutting force sensor with excellent accuracy, favorable natural frequency and acceptable cross-interference for high speed turning process. Octagonal ring is selected as sensitive element of the designed sensor, which is drawn inspiration from ring theory. A novel structure of two mutual-perpendicular octagonal rings is proposed and three Wheatstone full bridge circuits are specially organized in order to obtain triaxial cutting force components and restrain cross-interference. Firstly, the newly developed sensor is tested in static calibration; test results indicate that the sensor possesses outstanding accuracy in the range of 0.38%–0.83%. Secondly, impacting modal tests are conducted to identify the natural frequencies of the sensor in triaxial directions (i.e., 1147 Hz, 1122 Hz and 2035 Hz), which implies that the devised sensor can be used for cutting force measurement in a high speed lathe when the spindle speed does not exceed 17,205 rev/min in continuous cutting condition. Finally, an application of the sensor in turning process is operated to show its performance for real-time cutting force measurement; the measured cutting forces demonstrate a good accordance with the variation of cutting parameters. Thus, the developed sensor possesses perfect properties and it gains great potential for real-time cutting force measurement in turning. PMID:25855035

[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.

Meteorological measurements. Chapter 3

Treesearch

David Y. Hollinger

2008-01-01

Environmental measurements are useful for detecting climatic trends, understanding how the environment influences biological processes, and as input to ecosystem models. Landscape-scale monitoring requires a suite of environmental measures for all of these purposes, including air and soil temperature, humidity, wind speed, precipitation and soil moisture, and different...

Photoacoustics and speed-of-sound dual mode imaging with a long depth-of-field by using annular ultrasound array.

PubMed

Ding, Qiuning; Tao, Chao; Liu, Xiaojun

2017-03-20

Speed-of-sound and optical absorption reflect the structure and function of tissues from different aspects. A dual-mode microscopy system based on a concentric annular ultrasound array is proposed to simultaneously acquire the long depth-of-field images of speed-of-sound and optical absorption of inhomogeneous samples. First, speed-of-sound is decoded from the signal delay between each element of the annular array. The measured speed-of-sound could not only be used as an image contrast, but also improve the resolution and accuracy of spatial location of photoacoustic image in inhomogeneous acoustic media. Secondly, benefitting from dynamic focusing of annular array and the measured speed-of-sound, it is achieved an advanced acoustic-resolution photoacoustic microscopy with a precise position and a long depth-of-field. The performance of the dual-mode imaging system has been experimentally examined by using a custom-made annular array. The proposed dual-mode microscopy might have the significances in monitoring the biological physiological and pathological processes.

Experimental Evaluation of the High-Speed Motion Vector Measurement by Combining Synthetic Aperture Array Processing with Constrained Least Square Method

NASA Astrophysics Data System (ADS)

Yokoyama, Ryouta; Yagi, Shin-ichi; Tamura, Kiyoshi; Sato, Masakazu

2009-07-01

Ultrahigh speed dynamic elastography has promising potential capabilities in applying clinical diagnosis and therapy of living soft tissues. In order to realize the ultrahigh speed motion tracking at speeds of over thousand frames per second, synthetic aperture (SA) array signal processing technology must be introduced. Furthermore, the overall system performance should overcome the fine quantitative evaluation in accuracy and variance of echo phase changes distributed across a tissue medium. On spatial evaluation of local phase changes caused by pulsed excitation on a tissue phantom, investigation was made with the proposed SA signal system utilizing different virtual point sources that were generated by an array transducer to probe each component of local tissue displacement vectors. The final results derived from the cross-correlation method (CCM) brought about almost the same performance as obtained by the constrained least square method (LSM) extended to successive echo frames. These frames were reconstructed by SA processing after the real-time acquisition triggered by the pulsed irradiation from a point source. The continuous behavior of spatial motion vectors demonstrated the dynamic generation and traveling of the pulsed shear wave at a speed of one thousand frames per second.

Surface regions of illusory images are detected with a slower processing speed than those of luminance-defined images.

PubMed

Mihaylova, Milena; Manahilov, Velitchko

2010-11-24

Research has shown that the processing time for discriminating illusory contours is longer than for real contours. We know, however, little whether the visual processes, associated with detecting regions of illusory surfaces, are also slower as those responsible for detecting luminance-defined images. Using a speed-accuracy trade-off (SAT) procedure, we measured accuracy as a function of processing time for detecting illusory Kanizsa-type and luminance-defined squares embedded in 2D static luminance noise. The data revealed that the illusory images were detected at slower processing speed than the real images, while the points in time, when accuracy departed from chance, were not significantly different for both stimuli. The classification images for detecting illusory and real squares showed that observers employed similar detection strategies using surface regions of the real and illusory squares. The lack of significant differences between the x-intercepts of the SAT functions for illusory and luminance-modulated stimuli suggests that the detection of surface regions of both images could be based on activation of a single mechanism (the dorsal magnocellular visual pathway). The slower speed for detecting illusory images as compared to luminance-defined images could be attributed to slower processes of filling-in of regions of illusory images within the dorsal pathway.

Acquisition of Programming Skills

DTIC Science & Technology

1990-04-01

skills (e.g., arithmetic reasoning, work knowledge, information processing speed); and c) passive versus active learning style. Ability measures...concurrent storage and processing an individual was capable of doing), and an active learning style. Implications of the findings for the development of

Dynamic displacement measurement of large-scale structures based on the Lucas-Kanade template tracking algorithm

NASA Astrophysics Data System (ADS)

Guo, Jie; Zhu, Chang`an

2016-01-01

The development of optics and computer technologies enables the application of the vision-based technique that uses digital cameras to the displacement measurement of large-scale structures. Compared with traditional contact measurements, vision-based technique allows for remote measurement, has a non-intrusive characteristic, and does not necessitate mass introduction. In this study, a high-speed camera system is developed to complete the displacement measurement in real time. The system consists of a high-speed camera and a notebook computer. The high-speed camera can capture images at a speed of hundreds of frames per second. To process the captured images in computer, the Lucas-Kanade template tracking algorithm in the field of computer vision is introduced. Additionally, a modified inverse compositional algorithm is proposed to reduce the computing time of the original algorithm and improve the efficiency further. The modified algorithm can rapidly accomplish one displacement extraction within 1 ms without having to install any pre-designed target panel onto the structures in advance. The accuracy and the efficiency of the system in the remote measurement of dynamic displacement are demonstrated in the experiments on motion platform and sound barrier on suspension viaduct. Experimental results show that the proposed algorithm can extract accurate displacement signal and accomplish the vibration measurement of large-scale structures.

Associations between cognitive and gait performance during single- and dual-task walking in people with Parkinson disease.

PubMed

Stegemöller, Elizabeth L; Wilson, Jonathan P; Hazamy, Audrey; Shelley, Mack C; Okun, Michael S; Altmann, Lori J P; Hass, Chris J

2014-06-01

Cognitive impairments in Parkinson disease (PD) manifest as deficits in speed of processing, working memory, and executive function and attention abilities. The gait impairment in PD is well documented to include reduced speed, shortened step lengths, and increased step-to-step variability. However, there is a paucity of research examining the relationship between overground walking and cognitive performance in people with PD. This study sought to examine the relationship between both the mean and variability of gait spatiotemporal parameters and cognitive performance across a broad range of cognitive domains. A cross-sectional design was used. Thirty-five participants with no dementia and diagnosed with idiopathic PD completed a battery of 12 cognitive tests that yielded 3 orthogonal factors: processing speed, working memory, and executive function and attention. Participants completed 10 trials of overground walking (single-task walking) and 5 trials of overground walking while counting backward by 3's (dual-task walking). All gait measures were impaired by the dual task. Cognitive processing speed correlated with stride length and walking speed. Executive function correlated with step width variability. There were no significant associations with working memory. Regression models relating speed of processing to gait spatiotemporal variables revealed that including dual-task costs in the model significantly improved the fit of the model. Participants with PD were tested only in the on-medication state. Different characteristics of gait are related to distinct types of cognitive processing, which may be differentially affected by dual-task walking due to the pathology of PD. © 2014 American Physical Therapy Association.

Advanced Digital Signal Processing for Hybrid Lidar FY 2014

DTIC Science & Technology

2014-10-30

processing steps on raw data, with a PC miming Lab VIEW performing the fmal calculations to obtain range measurements . A MATLAB- based system...regarding the object and it reduces the image contrast and resolution as well as the object ranging measurement accuracy. There have been various...frequency (>100MHz) approach that uses high speed modulation to help suppress backscatter while also providing an unambiguous range measurement . In general

Factor Structure and Validity of Paper-and-Pencil Measures of Mental Speed: Evidence for a Higher-Order Model?

ERIC Educational Resources Information Center

Danthiir, Vanessa; Wilhelm, Oliver; Schulze, Ralf; Roberts, Richard D.

2005-01-01

This study explored the structure of elementary cognitive tasks (ECTs) and relations between the corresponding construct(s) with processing speed (Gs) and fluid intelligence (Gf). Participants (N=321) completed 14 ECTs, 3 Gs, and 6 Gf marker tests, all administered in paper-and-pencil format to reduce potential confounds evident when tasks are…

Adaptive functioning following pediatric traumatic brain injury: Relationship to executive function and processing speed.

PubMed

Shultz, Emily L; Hoskinson, Kristen R; Keim, Madelaine C; Dennis, Maureen; Taylor, H Gerry; Bigler, Erin D; Rubin, Kenneth H; Vannatta, Kathryn; Gerhardt, Cynthia A; Stancin, Terry; Yeates, Keith Owen

2016-10-01

Pediatric traumatic brain injury (TBI) may affect children's ability to perform everyday tasks (i.e., adaptive functioning). Guided by the American Association for Intellectual and Developmental Disabilities (AAIDD) model, we explored the association between TBI and adaptive functioning at increasing levels of specificity (global, AAIDD domains, and subscales). We also examined the contributions of executive function and processing speed as mediators of TBI's effects on adaptive functioning. Children (ages 8-13) with severe TBI (STBI; n = 19), mild-moderate TBI (MTBI; n = 50), or orthopedic injury (OI; n = 60) completed measures of executive function (TEA-Ch) and processing speed (WISC-IV) an average of 2.7 years postinjury (SD = 1.2; range: 1-5.3). Parents rated children's adaptive functioning (ABAS-II, BASC-2, CASP). STBI had lower global adaptive functioning (η2 = .04-.08) than the MTBI and OI groups, which typically did not differ. Deficits in the STBI group were particularly evident in the social domain, with specific deficits in social participation, leisure, and social adjustment (η2 = .06-.09). Jointly, executive function and processing speed were mediators of STBI's effects on global adaptive functioning and in conceptual and social domains. In the STBI group, executive function mediated social functioning, and processing speed mediated social participation. Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills. Executive function and processing speed may mediate the effects of STBI on adaptive functioning. Targeting adaptive functioning and associated cognitive deficits for intervention may enhance quality of life for pediatric TBI survivors. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Adaptive functioning following pediatric traumatic brain injury: Relationship to executive function and processing speed

PubMed Central

Shultz, Emily; Robinson, Kristen E.; Keim, Madelaine; Dennis, Maureen; Taylor, H. Gerry; Bigler, Erin D.; Rubin, Kenneth H.; Vannatta, Kathryn; Gerhardt, Cynthia A.; Stancin, Terry; Yeates, Keith Owen

2016-01-01

Objective Pediatric traumatic brain injury (TBI) may affect children’s ability to perform everyday tasks (i.e., adaptive functioning). Guided by the American Association for Intellectual and Developmental Disabilities (AAIDD) model, we explored the association between TBI and adaptive functioning at increasing levels of specificity (global, AAIDD domains, and subscales). We also examined the contributions of executive function and processing speed as mediators of TBI’s effects on adaptive functioning. Method Children (ages 8–13) with severe TBI (STBI; n=19), mild-moderate TBI (MTBI; n=50), or orthopedic injury (OI; n=60) completed measures of executive function (TEA-Ch) and processing speed (WISC-IV) an average of 2.7 years post-injury (SD = 1.2; range: 1–5.3). Parents rated children’s adaptive functioning (ABAS-II, BASC-2, CASP). Results STBI had lower global adaptive functioning (η2 = .04–.08) than the MTBI and OI groups, which typically did not differ. Deficits in the STBI group were particularly evident in the social domain, with specific deficits in social participation, leisure, and social adjustment (η2 = .06–.09). Jointly, executive function and processing speed were mediators of STBI’s effects on global adaptive functioning and in conceptual and social domains. In the STBI group, executive function mediated social functioning, and processing speed mediated social participation. Conclusions Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills. Executive function and processing speed may mediate the effects of STBI on adaptive functioning. Targeting adaptive functioning and associated cognitive deficits for intervention may enhance quality of life for pediatric TBI survivors. PMID:27182708

Online shaft encoder geometry compensation for arbitrary shaft speed profiles using Bayesian regression

NASA Astrophysics Data System (ADS)

Diamond, D. H.; Heyns, P. S.; Oberholster, A. J.

2016-12-01

The measurement of instantaneous angular speed is being increasingly investigated for its use in a wide range of condition monitoring and prognostic applications. Central to many measurement techniques are incremental shaft encoders recording the arrival times of shaft angular increments. The conventional approach to processing these signals assumes that the angular increments are equidistant. This assumption is generally incorrect when working with toothed wheels and especially zebra tape encoders and has been shown to introduce errors in the estimated shaft speed. There are some proposed methods in the literature that aim to compensate for this geometric irregularity. Some of the methods require the shaft speed to be perfectly constant for calibration, something rarely achieved in practice. Other methods assume the shaft speed to be nearly constant with minor deviations. Therefore existing methods cannot calibrate the entire shaft encoder geometry for arbitrary shaft speeds. The present article presents a method to calculate the shaft encoder geometry for arbitrary shaft speed profiles. The method uses Bayesian linear regression to calculate the encoder increment distances. The method is derived and then tested against simulated and laboratory experiments. The results indicate that the proposed method is capable of accurately determining the shaft encoder geometry for any shaft speed profile.

A new approach to correct yaw misalignment in the spinning ultrasonic anemometer

NASA Astrophysics Data System (ADS)

Ghaemi-Nasab, M.; Davari, Ali R.; Franchini, S.

2018-01-01

Single-axis ultrasonic anemometers are the modern instruments for accurate wind speed measurements. Despite their widespread and ever increasing applications, little attention has been paid up to now to spinning ultrasonic anemometers that can accurately measure both the wind speed and its direction in a single and robust apparatus. In this study, intensive wind-tunnel tests were conducted on a spinning single-axis ultrasonic anemometer to investigate the yaw misalignment in ultrasonic wind speed measurements during the yaw rotation. The anemometer was rotating inside the test section with various angular velocities, and the experiments were performed at several combinations of wind speed and anemometer angular velocity. The instantaneous angular position of the ultrasonic signal path with wind direction was measured using an angular position sensor. For a spinning anemometer, the circulatory wake and the associated flow distortion, along with the Doppler effect, impart a phase shift in the signals measured by the anemometer, which should be added to the position data for correcting the yaw misalignment. In this paper, the experimental data are used to construct a theoretical model, based on a response surface method, to correct the phase shift for various wind speeds and anemometer rotational velocities. This model is shown to successfully correct the velocity indicated by the spinning anemometer for the phase shift due to the rotation, and can easily be used in the calibration process for such anemometers.

N-terminal pro–brain natriuretic peptide and abnormal brain aging

PubMed Central

Sabayan, Behnam; van Buchem, Mark A.; de Craen, Anton J.M.; Sigurdsson, Sigurdur; Zhang, Qian; Harris, Tamara B.; Gudnason, Vilmundur; Arai, Andrew E.

2015-01-01

Objective: To investigate the independent association of serum N-terminal fragment of the prohormone natriuretic peptide (NT-proBNP) with structural and functional features of abnormal brain aging in older individuals. Methods: In this cross-sectional study based on the Age, Gene/Environment Susceptibility (AGES)–Reykjavik Study, we included 4,029 older community-dwelling individuals (born 1907 to 1935) with a measured serum level of NT-proBNP. Outcomes included parenchymal brain volumes estimated from brain MRI, cognitive function measured by tests of memory, processing speed, and executive functioning, and presence of depressive symptoms measured using the Geriatric Depression Scale. In a substudy, cardiac output of 857 participants was assessed using cardiac MRI. Results: In multivariate analyses, adjusted for sociodemographic and cardiovascular factors, higher levels of NT-proBNP were independently associated with lower total (p < 0.001), gray matter (p < 0.001), and white matter (p = 0.001) brain volumes. Likewise, in multivariate analyses, higher levels of NT-proBNP were associated with worse scores in memory (p = 0.005), processing speed (p = 0.001), executive functioning (p < 0.001), and more depressive symptoms (p = 0.002). In the substudy, the associations of higher NT-proBNP with lower brain parenchymal volumes, impaired executive function and processing speed, and higher depressive symptoms were independent of the level of cardiac output. Conclusions: Higher serum levels of NT-proBNP, independent of cardiovascular risk factors and a measure of cardiac function, are linked with alterations in brain structure and function. Roles of natriuretic peptides in the process of brain aging need to be further elucidated. PMID:26231259

Are Auditory and Visual Processing Deficits Related to Developmental Dyslexia?

ERIC Educational Resources Information Center

Georgiou, George K.; Papadopoulos, Timothy C.; Zarouna, Elena; Parrila, Rauno

2012-01-01

The purpose of this study was to examine if children with dyslexia learning to read a consistent orthography (Greek) experience auditory and visual processing deficits and if these deficits are associated with phonological awareness, rapid naming speed and orthographic processing. We administered measures of general cognitive ability, phonological…

High-Speed, capacitance-based tip clearance sensing

NASA Astrophysics Data System (ADS)

Haase, W. C.; Haase, Z. S.

This paper discusses recent advances in tip clearance measurement systems for turbine engines using capacitive probes. Real time measurements of individual blade pulses are generated using wideband signal processing providing 3 dB bandwidths of typically 5 MHz. Subsequent mixed-signal processing circuitry provide real-time measurements of maximum, minimum, and average clearance with latencies of one blade-to-blade time interval. Both guarded and unguarded probe configurations are possible with the system. Calibration techniques provide high accuracy measurements.

Tunneling Flight Time, Chemistry, and Special Relativity.

PubMed

Petersen, Jakob; Pollak, Eli

2017-09-07

Attosecond ionization experiments have not resolved the question "What is the tunneling time?". Different definitions of tunneling time lead to different results. Second, a zero tunneling time for a material particle suggests that the nonrelativistic theory includes speeds greater than the speed of light. Chemical reactions, occurring via tunneling, should then not be considered in terms of a nonrelativistic quantum theory calling into question quantum dynamics computations on tunneling reactions. To answer these questions, we define a new experimentally measurable paradigm, the tunneling flight time, and show that it vanishes for scattering through an Eckart or a square barrier, irrespective of barrier length or height, generalizing the Hartman effect. We explain why this result does not lead to experimental measurement of speeds greater than the speed of light. We show that this tunneling is an incoherent process by comparing a classical Wigner theory with exact quantum mechanical computations.

Brain Training Game Improves Executive Functions and Processing Speed in the Elderly: A Randomized Controlled Trial

PubMed Central

Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Akitsuki, Yuko; Shigemune, Yayoi; Sekiguchi, Atsushi; Kotozaki, Yuka; Tsukiura, Takashi; Yomogida, Yukihito; Kawashima, Ryuta

2012-01-01

Background The beneficial effects of brain training games are expected to transfer to other cognitive functions, but these beneficial effects are poorly understood. Here we investigate the impact of the brain training game (Brain Age) on cognitive functions in the elderly. Methods and Results Thirty-two elderly volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). This study was completed by 14 of the 16 members in the Brain Age group and 14 of the 16 members in the Tetris group. To maximize the benefit of the interventions, all participants were non-gamers who reported playing less than one hour of video games per week over the past 2 years. Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Each group played for a total of about 20 days. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into four categories (global cognitive status, executive functions, attention, and processing speed). Results showed that the effects of the brain training game were transferred to executive functions and to processing speed. However, the brain training game showed no transfer effect on any global cognitive status nor attention. Conclusions Our results showed that playing Brain Age for 4 weeks could lead to improve cognitive functions (executive functions and processing speed) in the elderly. This result indicated that there is a possibility which the elderly could improve executive functions and processing speed in short term training. The results need replication in large samples. Long-term effects and relevance for every-day functioning remain uncertain as yet. Trial Registration UMIN Clinical Trial Registry 000002825 PMID:22253758

Gas exchange-wind speed relation measured with sulfur hexafluoride on a lake

NASA Technical Reports Server (NTRS)

Wanninkhof, R.; Broecker, W. S.; Ledwell, J. R.

1985-01-01

Gas-exchange processes control the uptake and release of various gases in natural systems such as oceans, rivers, and lakes. Not much is known about the effect of wind speed on gas exchange in such systems. In the experiment described here, sulfur hexafluoride was dissolved in lake water, and the rate of escape of the gas with wind speed (at wind speeds up to 6 meters per second) was determined over a 1-month period. A sharp change in the wind speed dependence of the gas-exchange coefficient was found at wind speeds of about 2.4 meters per second, in agreement with the results of wind-tunnel studies. However the gas-exchange coefficients at wind speeds above 3 meters per second were smaller than those observed in wind tunnels and are in agreement with earlier lake and ocean results.

Effects on Vibration and Surface Roughness in High Speed Micro End-Milling of Inconel 718 with Minimum Quantity Lubrication

NASA Astrophysics Data System (ADS)

Rahman, Mohamed Abd; Yeakub Ali, Mohammad; Saddam Khairuddin, Amir

2017-03-01

This paper presents the study on vibration and surface roughness of Inconel 718 workpiece produced by micro end-milling using Mikrotools Integrated Multi-Process machine tool DT-110 with control parameters; spindle speed (15000 rpm and 30000 rpm), feed rate (2 mm/min and 4 mm/min) and depth of cut (0.10 mm and 0.15mm). The vibration was measured using DYTRAN accelerometer instrument and the average surface roughness Ra was measured using Wyko NT1100. The analysis of variance (ANOVA) by using Design Expert software revealed that feed rate and depth of cut are the most significant factors on vibration meanwhile for average surface roughness, Ra, spindle speed is the most significant factor.

Reduction of tablet weight variability by optimizing paddle speed in the forced feeder of a high-speed rotary tablet press.

PubMed

Peeters, Elisabeth; De Beer, Thomas; Vervaet, Chris; Remon, Jean-Paul

2015-04-01

Tableting is a complex process due to the large number of process parameters that can be varied. Knowledge and understanding of the influence of these parameters on the final product quality is of great importance for the industry, allowing economic efficiency and parametric release. The aim of this study was to investigate the influence of paddle speeds and fill depth at different tableting speeds on the weight and weight variability of tablets. Two excipients possessing different flow behavior, microcrystalline cellulose (MCC) and dibasic calcium phosphate dihydrate (DCP), were selected as model powders. Tablets were manufactured via a high-speed rotary tablet press using design of experiments (DoE). During each experiment also the volume of powder in the forced feeder was measured. Analysis of the DoE revealed that paddle speeds are of minor importance for tablet weight but significantly affect volume of powder inside the feeder in case of powders with excellent flowability (DCP). The opposite effect of paddle speed was observed for fairly flowing powders (MCC). Tableting speed played a role in weight and weight variability, whereas changing fill depth exclusively influenced tablet weight. The DoE approach allowed predicting the optimum combination of process parameters leading to minimum tablet weight variability. Monte Carlo simulations allowed assessing the probability to exceed the acceptable response limits if factor settings were varied around their optimum. This multi-dimensional combination and interaction of input variables leading to response criteria with acceptable probability reflected the design space.

Analysis on influence of guide vanes closure laws of pump-turbine on load rejection transient process

NASA Astrophysics Data System (ADS)

Yao, Z.; Bi, H. L.; Huang, Q. S.; Li, Z. J.; Wang, Z. W.

2013-12-01

In load rejection transient process, the sudden shut down of guide vanes may cause units speed rise and a sharp increase in water hammer pressure of diversion system, which endangers the safety operation of the power plant. Adopting reasonable guide vane closure law is a kind of economic and effective measurement to reduce the water hammer pressure and limit rotational speed increases. In this paper, combined with Guangzhou Pumped Storage Power Station plant A, the load rejection condition under different guide vanes closure laws is calculated and the key factor of guide vanes closure laws on the impact of the load rejection transition process is analyzed. The different inflection points, which are the closure modes, on the impact of unit speed change, water level fluctuation of surge tank, and the pressure fluctuation of volute inlet and draft tube inlet are further discussed. By compared with the calculation results, a reasonable guide vanes inflection point position can be determined according to security requirements and a reasonable guide vanes closure law can be attained to effectively coordinate the unit speed rise and the rapid pressure change in the load rejection transient process.

Foucault's method for measuring the speed of light with modern apparatus

NASA Astrophysics Data System (ADS)

Vörös, Zoltán; Weihs, Gregor

2015-05-01

In this paper, we introduce two simple and inexpensive, yet quite accurate versions of the well-known Foucault method for measuring the speed of light. In a compact footprint of just 20 cm by 270 cm with readily available laboratory items, a rotating mirror taken from a laser printer, and a webcam, we obtained c=296\\720+/- 3000 km s-1, and c=302\\295+/- 3000 km s-1, respectively, both within less than a per cent of the defined value. The experiment also prepares students for extracting data through image processing.

Movement measurement of isolated skeletal muscle using imaging microscopy

NASA Astrophysics Data System (ADS)

Elias, David; Zepeda, Hugo; Leija, Lorenzo S.; Sossa, Humberto; de la Rosa, Jose I.

1997-05-01

An imaging-microscopy methodology to measure contraction movement in chemically stimulated crustacean skeletal muscle, whose movement speed is about 0.02 mm/s is presented. For this, a CCD camera coupled to a microscope and a high speed digital image acquisition system, allowing us to capture 960 images per second are used. The images are digitally processed in a PC and displayed in a video monitor. A maximal field of 0.198 X 0.198 mm2 and a spatial resolution of 3.5 micrometers are obtained.

High-speed event detector for embedded nanopore bio-systems.

PubMed

Huang, Yiyun; Magierowski, Sebastian; Ghafar-Zadeh, Ebrahim; Wang, Chengjie

2015-08-01

Biological measurements of microscopic phenomena often deal with discrete-event signals. The ability to automatically carry out such measurements at high-speed in a miniature embedded system is desirable but compromised by high-frequency noise along with practical constraints on filter quality and sampler resolution. This paper presents a real-time event-detection method in the context of nanopore sensing that helps to mitigate these drawbacks and allows accurate signal processing in an embedded system. Simulations show at least a 10× improvement over existing on-line detection methods.

The Role of Visual Processing Speed in Reading Speed Development

PubMed Central

Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

2013-01-01

A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children. PMID:23593117

The role of visual processing speed in reading speed development.

PubMed

Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

2013-01-01

A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children.

Histamine H1 receptor antagonist cetirizine impairs working memory processing speed, but not episodic memory.

PubMed

van Ruitenbeek, P; Vermeeren, A; Riedel, W J

2010-09-01

The histaminergic neurotransmitter system is currently under investigation as a target for drug treatment of cognitive deficits in clinical disorders. The therapeutic potential of new drugs may initially be screened using a model of histaminergic dysfunction, for example, as associated with the use of centrally active antihistamines. Of the selective second generation antihistamines, cetirizine has been found to have central nervous system effects. The aim of the present study was to determine whether cetirizine can be used as a tool to model cognitive deficits associated with histaminergic hypofunction. The study was conducted according to a three-way, double-blind, cross-over design. Treatments were single oral doses of cetirizine 10 and 20 mg and placebo. Effects on cognition were assessed using tests of word learning, memory scanning, vigilance, divided attention, tracking and visual information processing speed. Cetirizine 10 mg impaired tracking performance and both doses impaired memory scanning speed. None of the other measures indicated impaired performance. Cetirizine affects information processing speed, but these effects were not sufficient to serve as a model for cognitive deficits in clinical disorders.

Method and apparatus for thermal processing of semiconductor substrates

DOEpatents

Griffiths, Stewart K.; Nilson, Robert H.; Mattson, Brad S.; Savas, Stephen E.

2002-01-01

An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.

Method and apparatus for thermal processing of semiconductor substrates

DOEpatents

Griffiths, Stewart K.; Nilson, Robert H.; Mattson, Brad S.; Savas, Stephen E.

2000-01-01

An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.

A high speed implementation of the random decrement algorithm

NASA Technical Reports Server (NTRS)

Kiraly, L. J.

1982-01-01

The algorithm is useful for measuring net system damping levels in stochastic processes and for the development of equivalent linearized system response models. The algorithm works by summing together all subrecords which occur after predefined threshold level is crossed. The random decrement signature is normally developed by scanning stored data and adding subrecords together. The high speed implementation of the random decrement algorithm exploits the digital character of sampled data and uses fixed record lengths of 2(n) samples to greatly speed up the process. The contributions to the random decrement signature of each data point was calculated only once and in the same sequence as the data were taken. A hardware implementation of the algorithm using random logic is diagrammed and the process is shown to be limited only by the record size and the threshold crossing frequency of the sampled data. With a hardware cycle time of 200 ns and 1024 point signature, a threshold crossing frequency of 5000 Hertz can be processed and a stably averaged signature presented in real time.

Domain-Specific Impairment in Cognitive Control among Remitted Youth with a History of Major Depression

PubMed Central

Peters, Amy T.; Jacobs, Rachel H.; Crane, Natania A.; Ryan, Kelly A.; Weisenbach, Sara L.; Ajilore, Olusola; Lamar, Melissa; Kassel, Michelle T.; Gabriel, Laura B.; West, Amy E.; Zubieta, Jon-Kar; Langenecker, Scott A.

2016-01-01

Aim Impairment in neuropsychological functioning is common in major depressive disorder (MDD), but it is not clear to what degree these deficits are related to risk (e.g., trait), scar, burden, or state effects of MDD. The objective of this study was to use neuropsychological measures, with factor scores in verbal fluency, processing speed, attention, set-shifting, and cognitive control in a unique population of young, remitted, un-medicated, early course individuals with a history of MDD in hopes of identifying putative trait markers of MDD. Methods Youth aged 18-23 in remission from MDD (rMDD; n = 62) and healthy controls (HC; n = 43) were assessed with neuropsychological tests at two time points. These were from four domains of executive functioning, consistent with previous literature as impaired in MDD; verbal fluency and processing speed, conceptual reasoning and set-shifting, processing speed with interference resolution, and cognitive control. Results rMDD youth performed comparably to healthy controls on verbal fluency and processing speed, processing speed with interference resolution, and conceptual reasoning and set-shifting, reliably over time. Individuals with rMDD demonstrated relative decrements in cognitive control at Time 1, with greater stability than HC participants. Conclusion MDD may be characterized by regulatory difficulties that do not pertain specifically to active mood state or fluctuations in symptoms. Deficient cognitive control may represent a trait vulnerability or early course scar of MDD that may prove a viable target for secondary prevention or early remediation PMID:26177674

Training attentional control in older adults.

PubMed

Mackay-Brandt, Anna

2011-07-01

Recent research has demonstrated benefits for older adults from training attentional control using a variable priority strategy, but the construct validity of the training task and the degree to which benefits of training transfer to other contexts are unclear. The goal of this study was to characterize baseline performance on the training task in a sample of 105 healthy older adults and to test for transfer of training in a subset (n = 21). Training gains after 5 days and extent of transfer was compared to another subset (n = 20) that served as a control group. Baseline performance on the training task was characterized by a two-factor model of working memory and processing speed. Processing speed correlated with the training task. Training gains in speed and accuracy were reliable and robust (ps <.001, η(2) = .57 to .90). Transfer to an analogous task was observed (ps <.05, η(2) = .10 to .17). The beneficial effect of training did not translate to improved performance on related measures of processing speed. This study highlights the robust effect of training and transfer to a similar context using a variable priority training task. Although processing speed is an important aspect of the training task, training benefit is either related to an untested aspect of the training task or transfer of training is limited to the training context.

Characterization of material parameters for high speed forming and cutting via experiment and inverse simulation

NASA Astrophysics Data System (ADS)

Scheffler, Christian; Psyk, Verena; Linnemann, Maik; Tulke, Marc; Brosius, Alexander; Landgrebe, Dirk

2018-05-01

High speed velocity effects in production technology provide a broad range of technological and economic advantages [1, 2]. However, exploiting them necessitates the knowledge of strain rate dependent material behavior in process modelling. In general, high speed material data characterization features several difficulties and requires sophisticated approaches in order to provide reliable material data. This paper proposes two innovative concepts with electromagnetic and pneumatic drive and an approach for material characterization in terms of strain rate dependent flow curves and parameters of failure or damage models. The test setups have been designed for investigations of strain rates up to 105 s-1. In principle, knowledge about the temporary courses and local distributions of stress and strain in the specimen is essential for identifying material characteristics, but short process times, fast changes of the measurement values, small specimen size and frequently limited accessibility of the specimen during the test hinder directly measuring these parameters at high-velocity testing. Therefore, auxiliary test parameters, which are easier to measure, are recorded and used as input data for an inverse numerical simulation that provides the desired material characteristics, e.g. the Johnson-Cook parameters, as a result. These parameters are a force equivalent strain signal on a measurement body and the displacement of the upper specimen edge.

Laser speckle velocimetry for robot manufacturing

NASA Astrophysics Data System (ADS)

Charrett, Thomas O. H.; Bandari, Yashwanth K.; Michel, Florent; Ding, Jialuo; Williams, Stewart W.; Tatam, Ralph P.

2017-06-01

A non-contact speckle correlation sensor for the measurement of robotic tool speed is presented for use in robotic manufacturing and is capable of measuring the in-plane relative velocities between a robot end-effector and the workpiece or other surface. The sensor performance was assessed in the laboratory with the sensor accuracies found to be better than 0:01 mm/s over a 70 mm/s velocity range. Finally an example of the sensors application to robotic manufacturing is presented where the sensor was applied to tool speed measurement for path planning in the wire and arc additive manufacturing process using a KUKA KR150 L110/2 industrial robot.

A New Fiber Preform with Nanocarbon Binder for Manufacturing Carbon Fiber Reinforced Composite by Liquid Molding Process.

PubMed

Seong, Dong Gi; Ha, Jong Rok; Lee, Jea Uk; Lee, Wonoh; Kim, Byung Sun

2015-11-01

Carbon fiber reinforced composite has been a good candidate of lightweight structural component in the automotive industry. As fast production speed is essential to apply the composite materials for the mass production area such as automotive components, the high speed liquid composite molding processes have been developed. Fast resin injection through the fiber preform by high pressure is required to improve the production speed, but it often results in undesirable deformations of the fiber preform which causes defectives in size and properties of the final composite products. In order to prevent the undesirable deformation and improve the stability of preform shape, polymer type binder materials are used. More stable fiber preform can be obtained by increasing the amount of binder material, but it disturbs the resin impregnation through the fiber preform. In this study, carbon nanomaterials such as graphene oxide were embedded on the surface of carbon fiber by electrophoretic deposition method in order to improve the shape stability of fiber preform and interfacial bonding between polymer and the reinforcing fiber. Effects of the modified reinforcing fiber were investigated in two respects. One is to increase the binding energy between fiber tows, and the other is to increase the interfacial bonding between polymer matrix and fiber surface. The effects were analyzed by measuring the binding force of fiber preform and interlaminar shear strength of the composite. This study also investigated the high speed liquid molding process of the composite materials composed of polymer matrix and the carbon fiber preforms embedded by carbon nanomaterials. Process parameter such as permeability of fiber preform was measured to investigate the effect of nanoscale surface modification on the macroscale processing condition for composite manufacturing.

Normative Data on Audiovisual Speech Integration Using Sentence Recognition and Capacity Measures

PubMed Central

Altieri, Nicholas; Hudock, Daniel

2016-01-01

Objective The ability to use visual speech cues and integrate them with auditory information is important, especially in noisy environments and for hearing-impaired (HI) listeners. Providing data on measures of integration skills that encompass accuracy and processing speed will benefit researchers and clinicians. Design The study consisted of two experiments: First, accuracy scores were obtained using CUNY sentences, and capacity measures that assessed reaction-time distributions were obtained from a monosyllabic word recognition task. Study Sample We report data on two measures of integration obtained from a sample comprised of 86 young and middle-age adult listeners: Results To summarize our results, capacity showed a positive correlation with accuracy measures of audiovisual benefit obtained from sentence recognition. More relevant, factor analysis indicated that a single-factor model captured audiovisual speech integration better than models containing more factors. Capacity exhibited strong loadings on the factor, while the accuracy-based measures from sentence recognition exhibited weaker loadings. Conclusions Results suggest that a listener’s integration skills may be assessed optimally using a measure that incorporates both processing speed and accuracy. PMID:26853446

Normative data on audiovisual speech integration using sentence recognition and capacity measures.

PubMed

Altieri, Nicholas; Hudock, Daniel

2016-01-01

The ability to use visual speech cues and integrate them with auditory information is important, especially in noisy environments and for hearing-impaired (HI) listeners. Providing data on measures of integration skills that encompass accuracy and processing speed will benefit researchers and clinicians. The study consisted of two experiments: First, accuracy scores were obtained using City University of New York (CUNY) sentences, and capacity measures that assessed reaction-time distributions were obtained from a monosyllabic word recognition task. We report data on two measures of integration obtained from a sample comprised of 86 young and middle-age adult listeners: To summarize our results, capacity showed a positive correlation with accuracy measures of audiovisual benefit obtained from sentence recognition. More relevant, factor analysis indicated that a single-factor model captured audiovisual speech integration better than models containing more factors. Capacity exhibited strong loadings on the factor, while the accuracy-based measures from sentence recognition exhibited weaker loadings. Results suggest that a listener's integration skills may be assessed optimally using a measure that incorporates both processing speed and accuracy.

Thermographic measurements of high-speed metal cutting

NASA Astrophysics Data System (ADS)

Mueller, Bernhard; Renz, Ulrich

2002-03-01

Thermographic measurements of a high-speed cutting process have been performed with an infrared camera. To realize images without motion blur the integration times were reduced to a few microseconds. Since the high tool wear influences the measured temperatures a set-up has been realized which enables small cutting lengths. Only single images have been recorded because the process is too fast to acquire a sequence of images even with the frame rate of the very fast infrared camera which has been used. To expose the camera when the rotating tool is in the middle of the camera image an experimental set-up with a light barrier and a digital delay generator with a time resolution of 1 ns has been realized. This enables a very exact triggering of the camera at the desired position of the tool in the image. Since the cutting depth is between 0.1 and 0.2 mm a high spatial resolution was also necessary which was obtained by a special close-up lens allowing a resolution of app. 45 microns. The experimental set-up will be described and infrared images and evaluated temperatures of a titanium alloy and a carbon steel will be presented for cutting speeds up to 42 m/s.

Improving Sensitivity to Detect Mild Cognitive Impairment: Cognitive Load Dual-Task Gait Speed Assessment.

PubMed

MacAulay, Rebecca K; Wagner, Mark T; Szeles, Dana; Milano, Nicholas J

2017-07-01

Longitudinal research indicates that cognitive load dual-task gait assessment is predictive of cognitive decline and thus might provide a sensitive measure to screen for mild cognitive impairment (MCI). However, research among older adults being clinically evaluated for cognitive concerns, a defining feature of MCI, is lacking. The present study investigated the effect of performing a cognitive task on normal walking speed in patients presenting to a memory clinic with cognitive complaints. Sixty-one patients with a mean age of 68 years underwent comprehensive neuropsychological testing, clinical interview, and gait speed (simple- and dual-task conditions) assessments. Thirty-four of the 61 patients met criteria for MCI. Repeated measure analyses of covariance revealed that greater age and MCI both significantly associated with slower gait speed, ps<.05. Follow-up analysis indicated that the MCI group had significantly slower dual-task gait speed but did not differ in simple-gait speed. Multivariate linear regression across groups found that executive attention performance accounted for 27.4% of the variance in dual-task gait speed beyond relevant demographic and health risk factors. The present study increases the external validity of dual-task gait assessment of MCI. Differences in dual-task gait speed appears to be largely attributable to executive attention processes. These findings have clinical implications as they demonstrate expected patterns of gait-brain behavior relationships in response to a cognitive dual task within a clinically representative population. Cognitive load dual-task gait assessment may provide a cost efficient and sensitive measure to detect older adults at high risk of a dementia disorder. (JINS, 2017, 23, 493-501).

The role of neuropsychological performance in the relationship between chronic pain and functional physical impairment.

PubMed

Pulles, Wiesje L J A; Oosterman, Joukje M

2011-12-01

  In this study, the relationship between pain intensity, neuropsychological, and physical function in adult chronic pain patients was examined.   Thirty participants with chronic pain completed neuropsychological tests tapping mental processing speed, memory, and executive function. Pain intensity was measured with three visual analog scales and the Pain Rating Index of the McGill Pain Questionnaire. A grip strength test, the 6-minute walk test, the Unipedal Stance Test and the Lifting Low Test were administered in order to obtain a performance-based measure of physical capacity. Self-reported physical ability was assessed with the Disability Rating Index and the Short Form-36 Physical Functioning, and Role Physical scales. Psychosocial function was examined using the Mental Health and Role Emotional subscales of the Short Form-36.   The study was set in two outpatient physical therapy clinics in The Netherlands.   The analysis showed that a lower mental processing speed was related to a higher level of pain, as well as to a lower performance-based and self-reported physical functioning. In addition, both performance-based and self-reported physical function revealed an inverse correlation with pain intensity. Psychosocial function turned out to be an important mediator of the relationship between pain and self-reported, but not performance-based, physical function. Mental processing speed, on the other hand, was found to mediate the relationship between pain and performance-based physical functioning.   The results suggest that in chronic pain patients, mental processing speed mediates the relationship between pain and physical function. Wiley Periodicals, Inc.

Measuring the circular motion of small objects using laser stroboscopic images.

PubMed

Wang, Hairong; Fu, Y; Du, R

2008-01-01

Measuring the circular motion of a small object, including its displacement, speed, and acceleration, is a challenging task. This paper presents a new method for measuring repetitive and/or nonrepetitive, constant speed and/or variable speed circular motion using laser stroboscopic images. Under stroboscopic illumination, each image taken by an ordinary camera records multioutlines of an object in motion; hence, processing the stroboscopic image will be able to extract the motion information. We built an experiment apparatus consisting of a laser as the light source, a stereomicroscope to magnify the image, and a normal complementary metal oxide semiconductor camera to record the image. As the object is in motion, the stroboscopic illumination generates a speckle pattern on the object that can be recorded by the camera and analyzed by a computer. Experimental results indicate that the stroboscopic imaging is stable under various conditions. Moreover, the characteristics of the motion, including the displacement, the velocity, and the acceleration can be calculated based on the width of speckle marks, the illumination intensity, the duty cycle, and the sampling frequency. Compared with the popular high-speed camera method, the presented method may achieve the same measuring accuracy, but with much reduced cost and complexity.

Use of near-infrared spectroscopy and multipoint measurements for quality control of pharmaceutical drug products.

PubMed

Boiret, Mathieu; Chauchard, Fabien

2017-01-01

Near-infrared (NIR) spectroscopy is a non-destructive analytical technique that enables better-understanding and optimization of pharmaceutical processes and final drug products. The use in line is often limited by acquisition speed and sampling area. This work focuses on performing a multipoint measurement at high acquisition speed at the end of the manufacturing process on a conveyor belt system to control both the distribution and the content of active pharmaceutical ingredient within final drug products, i.e., tablets. A specially designed probe with several collection fibers was developed for this study. By measuring spectral and spatial information, it provides physical and chemical knowledge on the final drug product. The NIR probe was installed on a conveyor belt system that enables the analysis of a lot of tablets. The use of these NIR multipoint measurement probes on a conveyor belt system provided an innovative method that has the potential to be used as a new paradigm to ensure the drug product quality at the end of the manufacturing process and as a new analytical method for the real-time release control strategy. Graphical abstract Use of near-infrared spectroscopy and multipoint measurements for quality control of pharmaceutical drug products.

Chapter 22: Compressed Air Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

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

Kurnik, Charles W; Benton, Nathanael; Burns, Patrick

Compressed-air systems are used widely throughout industry for many operations, including pneumatic tools, packaging and automation equipment, conveyors, and other industrial process operations. Compressed-air systems are defined as a group of subsystems composed of air compressors, air treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications using compressed air. A compressed-air system has three primary functional subsystems: supply, distribution, and demand. Air compressors are the primary energy consumers in a compressed-air system and are the primary focus of this protocol. The two compressed-air energy efficiency measures specifically addressed in this protocol are: High-efficiency/variable speed drive (VSD) compressormore » replacing modulating, load/unload, or constant-speed compressor; and Compressed-air leak survey and repairs. This protocol provides direction on how to reliably verify savings from these two measures using a consistent approach for each.« less

Useful field of view test.

PubMed

Wood, Joanne M; Owsley, Cynthia

2014-01-01

The useful field of view test was developed to reflect the visual difficulties that older adults experience with everyday tasks. Importantly, the useful field of view test (UFOV) is one of the most extensively researched and promising predictor tests for a range of driving outcomes measures, including driving ability and crash risk as well as other everyday tasks. Currently available commercial versions of the test can be administered using personal computers; these measure the speed of visual processing for rapid detection and localization of targets under conditions of divided visual attention and in the presence and absence of visual clutter. The test is believed to assess higher-order cognitive abilities, but performance also relies on visual sensory function because in order for targets to be attended to, they must be visible. The format of the UFOV has been modified over the years; the original version estimated the spatial extent of useful field of view, while the latest version measures visual processing speed. While deficits in the useful field of view are associated with functional impairments in everyday activities in older adults, there is also emerging evidence from several research groups that improvements in visual processing speed can be achieved through training. These improvements have been shown to reduce crash risk, and can have a positive impact on health and functional well-being, with the potential to increase the mobility and hence the independence of older adults. © 2014 S. Karger AG, Basel

Long-Term Deflection Prediction from Computer Vision-Measured Data History for High-Speed Railway Bridges

PubMed Central

Lee, Jaebeom; Lee, Young-Joo

2018-01-01

Management of the vertical long-term deflection of a high-speed railway bridge is a crucial factor to guarantee traffic safety and passenger comfort. Therefore, there have been efforts to predict the vertical deflection of a railway bridge based on physics-based models representing various influential factors to vertical deflection such as concrete creep and shrinkage. However, it is not an easy task because the vertical deflection of a railway bridge generally involves several sources of uncertainty. This paper proposes a probabilistic method that employs a Gaussian process to construct a model to predict the vertical deflection of a railway bridge based on actual vision-based measurement and temperature. To deal with the sources of uncertainty which may cause prediction errors, a Gaussian process is modeled with multiple kernels and hyperparameters. Once the hyperparameters are identified through the Gaussian process regression using training data, the proposed method provides a 95% prediction interval as well as a predictive mean about the vertical deflection of the bridge. The proposed method is applied to an arch bridge under operation for high-speed trains in South Korea. The analysis results obtained from the proposed method show good agreement with the actual measurement data on the vertical deflection of the example bridge, and the prediction results can be utilized for decision-making on railway bridge maintenance. PMID:29747421

Long-Term Deflection Prediction from Computer Vision-Measured Data History for High-Speed Railway Bridges.

PubMed

Lee, Jaebeom; Lee, Kyoung-Chan; Lee, Young-Joo

2018-05-09

Management of the vertical long-term deflection of a high-speed railway bridge is a crucial factor to guarantee traffic safety and passenger comfort. Therefore, there have been efforts to predict the vertical deflection of a railway bridge based on physics-based models representing various influential factors to vertical deflection such as concrete creep and shrinkage. However, it is not an easy task because the vertical deflection of a railway bridge generally involves several sources of uncertainty. This paper proposes a probabilistic method that employs a Gaussian process to construct a model to predict the vertical deflection of a railway bridge based on actual vision-based measurement and temperature. To deal with the sources of uncertainty which may cause prediction errors, a Gaussian process is modeled with multiple kernels and hyperparameters. Once the hyperparameters are identified through the Gaussian process regression using training data, the proposed method provides a 95% prediction interval as well as a predictive mean about the vertical deflection of the bridge. The proposed method is applied to an arch bridge under operation for high-speed trains in South Korea. The analysis results obtained from the proposed method show good agreement with the actual measurement data on the vertical deflection of the example bridge, and the prediction results can be utilized for decision-making on railway bridge maintenance.

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.

Flying fish accelerate at 5 G to leap from the water surface

NASA Astrophysics Data System (ADS)

Yang, Patricia; Phonekeo, Sulisay; Xu, Ke; Chang, Shui-Kai; Hu, David

2013-11-01

Flying fish can both swim underwater and glide in air. Transitioning from swimming to gliding requires penetration of the air-water interface, or breaking the ``surface tension barrier,'' a formidable task for juvenile flying fish measuring 1 to 5 cm in length. In this experimental investigation, we use high-speed videography to characterize the kinematics of juvenile flying fish as they leap from the water surface. During this process, which lasts 0.05 seconds, flying fish achieve body accelerations of 5 times earth's gravity and gliding speeds of 1.3 m/s, an order of magnitude higher than their steady swimming speed. We rationalize this anomalously high speed on the basis of the hydrodynamic and surface tension forces and torques experienced by the fish. Specifically, leaping fish experience skin friction forces only on the submerged part of their body, permitting them to achieve much higher speeds than in steady underwater swimming. We also perform experiments using a towed flying fish mimc to determine optimality of various parameters in this process, including body angle and start position with respect to the water surface.

Near-surface wind speed statistical distribution: comparison between ECMWF System 4 and ERA-Interim

NASA Astrophysics Data System (ADS)

Marcos, Raül; Gonzalez-Reviriego, Nube; Torralba, Verónica; Cortesi, Nicola; Young, Doo; Doblas-Reyes, Francisco J.

2017-04-01

In the framework of seasonal forecast verification, knowing whether the characteristics of the climatological wind speed distribution, simulated by the forecasting systems, are similar to the observed ones is essential to guide the subsequent process of bias adjustment. To bring some light about this topic, this work assesses the properties of the statistical distributions of 10m wind speed from both ERA-Interim reanalysis and seasonal forecasts of ECMWF system 4. The 10m wind speed distribution has been characterized in terms of the four main moments of the probability distribution (mean, standard deviation, skewness and kurtosis) together with the coefficient of variation and goodness of fit Shapiro-Wilks test, allowing the identification of regions with higher wind variability and non-Gaussian behaviour at monthly time-scales. Also, the comparison of the predicted and observed 10m wind speed distributions has been measured considering both inter-annual and intra-seasonal variability. Such a comparison is important in both climate research and climate services communities because it provides useful climate information for decision-making processes and wind industry applications.

Dynamic measurement of speed of sound in n-Heptane by ultrasonics during fuel injections.

PubMed

Minnetti, Elisa; Pandarese, Giuseppe; Evangelisti, Piersavio; Verdugo, Francisco Rodriguez; Ungaro, Carmine; Bastari, Alessandro; Paone, Nicola

2017-11-01

The paper presents a technique to measure the speed of sound in fuels based on pulse-echo ultrasound. The method is applied inside the test chamber of a Zeuch-type instrument used for indirect measurement of the injection rate (Mexus). The paper outlines the pulse-echo method, considering probe installation, ultrasound beam propagation inside the test chamber, typical signals obtained, as well as different processing algorithms. The method is validated in static conditions by comparing the experimental results to the NIST database both for water and n-Heptane. The ultrasonic system is synchronized to the injector so that time resolved samples of speed of sound can be successfully acquired during a series of injections. Results at different operating conditions in n-Heptane are shown. An uncertainty analysis supports the analysis of results and allows to validate the method. Experimental results show that the speed of sound variation during an injection event is less than 1%, so the Mexus model assumption to consider it constant during the injection is valid. Copyright © 2017 Elsevier B.V. All rights reserved.

How Safe Is High-Speed Burring in Spine Surgery? An In Vitro Study on the Effect of Rotational Speed and Heat Generation in the Bovine Spine.

PubMed

Singh, Taran Singh Pall; Yusoff, Abdul Halim; Chian, Yap Keat

2015-08-01

In vitro animal cadaveric study. To identify the appropriate rotational speed and safe bone distance from neural tissue during bone burring in spinal surgery. Bone burring is a common step in spinal surgery. Unwanted frictional heat produced during bone burring may result in thermal injury to the bone and adjacent neural structure. One of the important parameters influencing the bone temperature rise during bone burring is rotational speed. This laboratory-based animal study used bovine spine bones, and the tests were conducted using a steel round burr. The bone temperature was measured simultaneously with thermocouple at the distances of 1 mm, 3 mm, and 5 mm from the burring site during the burring process. The bone burring was done with 4 different rotational speeds of 35,000 revolutions per minute (rpm), 45,000 rpm, 65,000 rpm, and 75,000 rpm. This study showed that increasing the rotational speed significantly elevated bone temperature. The threshold temperature of 47°C was reached when bone was burred for 10 seconds, with a rotational speed of 45,000 rpm. The mean bone temperature measured at a distance 1 mm from the burring site for all 4 rotational speeds was always higher than that measured at a distance of 3 mm and 5 mm and this difference was statistically significant (P < 0.001). There was no significant difference between the mean bone temperature measured at a distance of 3 mm and 5 mm (P > 0.05). Taking 47°C as the threshold temperature for causing significant impairment to the regenerative capacity of bone, a rotational speed of lower than 45,000 rpm is preferable so as to minimize thermal injury to bone tissue. We also concluded that a 3-mm distance between the site of burring and the neural tissue is a safe distance. N/A.

Heat Control via Torque Control in Friction Stir Welding

NASA Technical Reports Server (NTRS)

Venable, Richard; Colligan, Kevin; Knapp, Alan

2004-01-01

In a proposed advance in friction stir welding, the torque exerted on the workpiece by the friction stir pin would be measured and controlled in an effort to measure and control the total heat input to the workpiece. The total heat input to the workpiece is an important parameter of any welding process (fusion or friction stir welding). In fusion welding, measurement and control of heat input is a difficult problem. However, in friction stir welding, the basic principle of operation affords the potential of a straightforward solution: Neglecting thermal losses through the pin and the spindle that supports it, the rate of heat input to the workpiece is the product of the torque and the speed of rotation of the friction stir weld pin and, hence, of the spindle. Therefore, if one acquires and suitably processes data on torque and rotation and controls the torque, the rotation, or both, one should be able to control the heat input into the workpiece. In conventional practice in friction stir welding, one uses feedback control of the spindle motor to maintain a constant speed of rotation. According to the proposal, one would not maintain a constant speed of rotation: Instead, one would use feedback control to maintain a constant torque and would measure the speed of rotation while allowing it to vary. The torque exerted on the workpiece would be estimated as the product of (1) the torque-multiplication ratio of the spindle belt and/or gear drive, (2) the force measured by a load cell mechanically coupled to the spindle motor, and (3) the moment arm of the load cell. Hence, the output of the load cell would be used as a feedback signal for controlling the torque (see figure).

A Vehicular Mobile Standard Instrument for Field Verification of Traffic Speed Meters Based on Dual-Antenna Doppler Radar Sensor

PubMed Central

Du, Lei; Sun, Qiao; Cai, Changqing; Bai, Jie; Fan, Zhe; Zhang, Yue

2018-01-01

Traffic speed meters are important legal measuring instruments specially used for traffic speed enforcement and must be tested and verified in the field every year using a vehicular mobile standard speed-measuring instrument to ensure speed-measuring performances. The non-contact optical speed sensor and the GPS speed sensor are the two most common types of standard speed-measuring instruments. The non-contact optical speed sensor requires extremely high installation accuracy, and its speed-measuring error is nonlinear and uncorrectable. The speed-measuring accuracy of the GPS speed sensor is rapidly reduced if the amount of received satellites is insufficient enough, which often occurs in urban high-rise regions, tunnels, and mountainous regions. In this paper, a new standard speed-measuring instrument using a dual-antenna Doppler radar sensor is proposed based on a tradeoff between the installation accuracy requirement and the usage region limitation, which has no specified requirements for its mounting distance and no limitation on usage regions and can automatically compensate for the effect of an inclined installation angle on its speed-measuring accuracy. Theoretical model analysis, simulated speed measurement results, and field experimental results compared with a GPS speed sensor with high accuracy showed that the dual-antenna Doppler radar sensor is effective and reliable as a new standard speed-measuring instrument. PMID:29621142

A Vehicular Mobile Standard Instrument for Field Verification of Traffic Speed Meters Based on Dual-Antenna Doppler Radar Sensor.

PubMed

Du, Lei; Sun, Qiao; Cai, Changqing; Bai, Jie; Fan, Zhe; Zhang, Yue

2018-04-05

Traffic speed meters are important legal measuring instruments specially used for traffic speed enforcement and must be tested and verified in the field every year using a vehicular mobile standard speed-measuring instrument to ensure speed-measuring performances. The non-contact optical speed sensor and the GPS speed sensor are the two most common types of standard speed-measuring instruments. The non-contact optical speed sensor requires extremely high installation accuracy, and its speed-measuring error is nonlinear and uncorrectable. The speed-measuring accuracy of the GPS speed sensor is rapidly reduced if the amount of received satellites is insufficient enough, which often occurs in urban high-rise regions, tunnels, and mountainous regions. In this paper, a new standard speed-measuring instrument using a dual-antenna Doppler radar sensor is proposed based on a tradeoff between the installation accuracy requirement and the usage region limitation, which has no specified requirements for its mounting distance and no limitation on usage regions and can automatically compensate for the effect of an inclined installation angle on its speed-measuring accuracy. Theoretical model analysis, simulated speed measurement results, and field experimental results compared with a GPS speed sensor with high accuracy showed that the dual-antenna Doppler radar sensor is effective and reliable as a new standard speed-measuring instrument.

An FPGA-based High Speed Parallel Signal Processing System for Adaptive Optics Testbed

NASA Astrophysics Data System (ADS)

Kim, H.; Choi, Y.; Yang, Y.

In this paper a state-of-the-art FPGA (Field Programmable Gate Array) based high speed parallel signal processing system (SPS) for adaptive optics (AO) testbed with 1 kHz wavefront error (WFE) correction frequency is reported. The AO system consists of Shack-Hartmann sensor (SHS) and deformable mirror (DM), tip-tilt sensor (TTS), tip-tilt mirror (TTM) and an FPGA-based high performance SPS to correct wavefront aberrations. The SHS is composed of 400 subapertures and the DM 277 actuators with Fried geometry, requiring high speed parallel computing capability SPS. In this study, the target WFE correction speed is 1 kHz; therefore, it requires massive parallel computing capabilities as well as strict hard real time constraints on measurements from sensors, matrix computation latency for correction algorithms, and output of control signals for actuators. In order to meet them, an FPGA based real-time SPS with parallel computing capabilities is proposed. In particular, the SPS is made up of a National Instrument's (NI's) real time computer and five FPGA boards based on state-of-the-art Xilinx Kintex 7 FPGA. Programming is done with NI's LabView environment, providing flexibility when applying different algorithms for WFE correction. It also facilitates faster programming and debugging environment as compared to conventional ones. One of the five FPGA's is assigned to measure TTS and calculate control signals for TTM, while the rest four are used to receive SHS signal, calculate slops for each subaperture and correction signal for DM. With this parallel processing capabilities of the SPS the overall closed-loop WFE correction speed of 1 kHz has been achieved. System requirements, architecture and implementation issues are described; furthermore, experimental results are also given.

Updating and Not Shifting Predicts Learning Performance in Young and Middle-Aged Adults

ERIC Educational Resources Information Center

Gijselaers, Hieronymus J. M.; Meijs, Celeste; Neroni, Joyce; Kirschner, Paul A.; de Groot, Renate H. M.

2017-01-01

The goal of this study was to investigate whether single executive function (EF) tests were predictive for learning performance in mainly young and middle-aged adults. The tests measured shifting and updating. Processing speed was also measured. In an observational study, cognitive performance and learning performance were measured objectively in…

N-terminal pro-brain natriuretic peptide and abnormal brain aging: The AGES-Reykjavik Study.

PubMed

Sabayan, Behnam; van Buchem, Mark A; de Craen, Anton J M; Sigurdsson, Sigurdur; Zhang, Qian; Harris, Tamara B; Gudnason, Vilmundur; Arai, Andrew E; Launer, Lenore J

2015-09-01

To investigate the independent association of serum N-terminal fragment of the prohormone natriuretic peptide (NT-proBNP) with structural and functional features of abnormal brain aging in older individuals. In this cross-sectional study based on the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study, we included 4,029 older community-dwelling individuals (born 1907 to 1935) with a measured serum level of NT-proBNP. Outcomes included parenchymal brain volumes estimated from brain MRI, cognitive function measured by tests of memory, processing speed, and executive functioning, and presence of depressive symptoms measured using the Geriatric Depression Scale. In a substudy, cardiac output of 857 participants was assessed using cardiac MRI. In multivariate analyses, adjusted for sociodemographic and cardiovascular factors, higher levels of NT-proBNP were independently associated with lower total (p < 0.001), gray matter (p < 0.001), and white matter (p = 0.001) brain volumes. Likewise, in multivariate analyses, higher levels of NT-proBNP were associated with worse scores in memory (p = 0.005), processing speed (p = 0.001), executive functioning (p < 0.001), and more depressive symptoms (p = 0.002). In the substudy, the associations of higher NT-proBNP with lower brain parenchymal volumes, impaired executive function and processing speed, and higher depressive symptoms were independent of the level of cardiac output. Higher serum levels of NT-proBNP, independent of cardiovascular risk factors and a measure of cardiac function, are linked with alterations in brain structure and function. Roles of natriuretic peptides in the process of brain aging need to be further elucidated. © 2015 American Academy of Neurology.

Current observations offshore Punta Tuna, Puerto Rico, 21 June-7 December 1980. Part A

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

Frye, D.; Leavitt, K.; Whitney, A.

1981-08-01

An oceanographic measurement program was conducted in the vicinity of a proposed ocean thermal energy conversion (OTEC) site about 20 km offshore of Punta Tuna, Puerto Rico. As part of the program, a mooring consisting of five current meters was maintained between 21 June and 7 December, 1980. The current data collected are summarized according to frequency of occurrence within 5 cm/sec speed and 15/sup 0/ direction intervals. Sums and percentages of total occurrence are given for each speed and direction class, along with mean speed, extreme speeds, mean component speeds, and standard deviations. Hourly averages of current speed, truemore » direction, current vector, temperature, and pressure are plotted as a function of time. On 13 December, 1980, a current meter array was deployed at the Punta Tuna site and recovered on May 16, 1981. The processed current data from this current meter array are described. (LEW)« less

Behavioural system identification of visual flight speed control in Drosophila melanogaster

PubMed Central

Rohrseitz, Nicola; Fry, Steven N.

2011-01-01

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles. PMID:20525744

Behavioural system identification of visual flight speed control in Drosophila melanogaster.

PubMed

Rohrseitz, Nicola; Fry, Steven N

2011-02-06

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles.

A fast positioning algorithm for the asymmetric dual Mach-Zehnder interferometric infrared fiber vibration sensor

NASA Astrophysics Data System (ADS)

Jiang, Junfeng; An, Jianchang; Liu, Kun; Ma, Chunyu; Li, Zhichen; Liu, Tiegen

2017-09-01

We propose a fast positioning algorithm for the asymmetric dual Mach-Zehnder interferometric infrared fiber vibration sensor. Using the approximately derivation method and the enveloping detection method, we successfully eliminate the asymmetry of the interference outputs and improve the processing speed. A positioning measurement experiment was carried out to verify the effectiveness of the proposed algorithm. At the sensing length of 85 km, the experimental results show that the mean positioning error is 18.9 m and the mean processing time is 116 ms. The processing speed is improved by 5 times compared to what can be achieved by using the traditional time-frequency analysis-based positioning method.

Learning, Attention/Hyperactivity, and Conduct Problems as Sequelae of Excessive Daytime Sleepiness in a General Population Study of Young Children

PubMed Central

Calhoun, Susan L.; Fernandez-Mendoza, Julio; Vgontzas, Alexandros N.; Mayes, Susan D.; Tsaoussoglou, Marina; Rodriguez-Muñoz, Alfredo; Bixler, Edward O.

2012-01-01

Study Objectives: Although excessive daytime sleepiness (EDS) is a common problem in children, with estimates of 15%; few studies have investigated the sequelae of EDS in young children. We investigated the association of EDS with objective neurocognitive measures and parent reported learning, attention/hyperactivity, and conduct problems in a large general population sample of children. Design: Cross-sectional. Setting: Population based. Participants: 508 children from The Penn State Child Cohort. Interventions: N/A. Measurements and Results: Children underwent a 9-h polysomnogram, comprehensive neurocognitive testing, and parent rating scales. Children were divided into 2 groups: those with and without parent-reported EDS. Structural equation modeling was used to examine whether processing speed and working memory performance would mediate the relationship between EDS and learning, attention/hyperactivity, and conduct problems. Logistic regression models suggest that parent-reported learning, attention/hyperactivity, and conduct problems, as well as objective measurement of processing speed and working memory are significant sequelae of EDS, even when controlling for AHI and objective markers of sleep. Path analysis demonstrates that processing speed and working memory performance are strong mediators of the association of EDS with learning and attention/hyperactivity problems, while to a slightly lesser degree are mediators from EDS to conduct problems. Conclusions: This study suggests that in a large general population sample of young children, parent-reported EDS is associated with neurobehavioral (learning, attention/hyperactivity, conduct) problems and poorer performance in processing speed and working memory. Impairment due to EDS in daytime cognitive and behavioral functioning can have a significant impact on children's development. Citation: Calhoun SL; Fernandez-Mendoza J; Vgontzas AN; Mayes SD; Tsaoussoglou M; Rodriguez-Muñoz A; Bixler EO. Learning, attention/hyperactivity, and conduct problems as sequelae of excessive daytime sleepiness in a general population study of young children. SLEEP 2012;35(5):627-632. PMID:22547888

Nonintrusive performance measurement of a gas turbine engine in real time

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

DeSilva, Upul P.; Claussen, Heiko

Performance of a gas turbine engine is monitored by computing a mass flow rate through the engine. Acoustic time-of-flight measurements are taken between acoustic transmitters and receivers in the flow path of the engine. The measurements are processed to determine average speeds of sound and gas flow velocities along those lines-of-sound. A volumetric flow rate in the flow path is computed using the gas flow velocities together with a representation of the flow path geometry. A gas density in the flow path is computed using the speeds of sound and a measured static pressure. The mass flow rate is calculatedmore » from the gas density and the volumetric flow rate.« less

Experimental analysis of IMEP in a rotary combustion engine

NASA Technical Reports Server (NTRS)

Schock, H. J.; Rice, W. J.; Meng, P. R.

1981-01-01

A real time indicated mean effective pressure measurement system is described which is used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate volume function in real time. Measurements at two engine speeds (2000 and 3000 rpm) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 rpm.

A high-speed tunable beam splitter for feed-forward photonic quantum information processing.

PubMed

Ma, Xiao-Song; Zotter, Stefan; Tetik, Nuray; Qarry, Angie; Jennewein, Thomas; Zeilinger, Anton

2011-11-07

We realize quantum gates for path qubits with a high-speed, polarization-independent and tunable beam splitter. Two electro-optical modulators act in a Mach-Zehnder interferometer as high-speed phase shifters and rapidly tune its splitting ratio. We test its performance with heralded single photons, observing a polarization-independent interference contrast above 95%. The switching time is about 5.6 ns, and a maximal repetition rate is 2.5 MHz. We demonstrate tunable feed-forward operations of a single-qubit gate of path-encoded qubits and a two-qubit gate via measurement-induced interaction between two photons.

The Complexities of Complex Memory Span: Storage and Processing Deficits in Specific Language Impairment

ERIC Educational Resources Information Center

Archibald, Lisa M. D.; Gathercole, Susan E.

2007-01-01

This study investigated the verbal and visuospatial processing and storage skills of children with SLI and typically developing children. Fourteen school-age children with SLI, and two groups of typically developing children matched either for age or language abilities, completed measures of processing speed and storage capacity, and a set of…

Cognitive switching processes in young people with attention-deficit/hyperactivity disorder.

PubMed

Oades, Robert D; Christiansen, Hanna

2008-01-01

Patients with attention-deficit/hyperactivity disorder (ADHD) can be slow at switching between stimuli, or between sets of stimuli to control behaviour appropriate to changing situations. We examined clinical and experimental parameters that may influence the speed of such processes measured in the trail-making (TMT) and switch-tasks in cases with ADHD combined type, their non-affected siblings and unrelated healthy controls. The latency for completion of the trail-making task controlling for psychomotor processing (TMT-B-A) was longer for ADHD cases, and correlated with Conners' ratings of symptom severity across all subjects. The effect decreased with age. Switch-task responses to questions of "Which number?" and "How many?" between sets of 1/111 or 3/333 elicited differential increases in latency with condition that affected all groups. But there was evidence for increased symptom-related intra-individual variability among the ADHD cases, and across all subjects. Young siblings showed familiality for some measures of TMT and switch-task performance but these were modest. The potential influences of moderator variables on the efficiency of processing stimulus change rather than the speed of processing are discussed.

High-speed imaging of the transient ice accretion process on a NACA 0012 airfoil

NASA Astrophysics Data System (ADS)

Waldman, Rye; Hu, Hui

2014-11-01

Ice accretion on aircraft wings poses a performance and safety threat as aircraft encounter supercooled droplets suspended in the cloud layer. The details of the ice accretion depend on the atmospheric conditions and the fight parameters. We present the measurement results of the experiments conducted in the Iowa State icing wind tunnel on a NACA 0012 airfoil to study the transient ice accretion process under varying icing conditions. The icing process on the wing consists of a complex interaction of water deposition, surface water transport, and freezing. The aerodynamics affects the water deposition, the heat and mass transport, and ice accumulation; meanwhile, the accumulating ice also affects the aerodynamics. High-speed video of the unsteady icing accretion process was acquired under controlled environmental conditions to quantitatively measure the transient water run back, rivulet formation, and accumulated ice growth, and the experiments show how varying the environmental conditions modifies the ice accretion process. Funding support from the Iowa Energy Center with Grant No. 14-008-OG and National Science Foundation (NSF) with Grant No. CBET-1064196 and CBET-1438099 is gratefully acknowledged.

Field and Numerical Study of the Columbia River Mouth

DTIC Science & Technology

2013-09-30

system pole-mounted to the USGS survey vessel R/V Parke Snavely. Positioning and orientation of the transducers were measured using an Applanix ...POS MV 320 and afterwards post-processed using Applanix POSPac MMS software. Continuous speed of sound measurements were collected using an Applied

Effect of rotation speed and welding speed on Friction Stir Welding of AA1100 Aluminium alloy

NASA Astrophysics Data System (ADS)

Raja, P.; Bojanampati, S.; Karthikeyan, R.; Ganithi, R.

2018-04-01

Aluminum AA1100 is the most widely used grade of Aluminium due to its excellent corrosion resistance, high ductility and reflective finish, the selected material was welded with Friction Stir Welding (FSW) process on a CNC machine, using a combination of different tool rotation speed (1500 rpm, 2500 rpm, 3500 rpm) and welding speed (10 mm/min, 30 mm/min, 50 mm/min) as welding parameters. The effect of FSW using this welding parameter was studied by measuring the ultimate tensile strength of the welded joints. A high-speed steel tool was prepared for welding the Aluminium AA1100 alloy having an 8mm shoulder diameter and pin dimension of 4mm diameter and 2.8 mm length. The welded joints were tested using the universal testing machine. It was found that Ultimate Tensile Strength of FSW specimen was highest with a value of 98.08 MPa when the weld was performed at rotation speed of 1500 RPM and welding speed of 50 mm/min.

Rolling element bearing defect diagnosis under variable speed operation through angle synchronous averaging of wavelet de-noised estimate

NASA Astrophysics Data System (ADS)

Mishra, C.; Samantaray, A. K.; Chakraborty, G.

2016-05-01

Rolling element bearings are widely used in rotating machines and their faults can lead to excessive vibration levels and/or complete seizure of the machine. Under special operating conditions such as non-uniform or low speed shaft rotation, the available fault diagnosis methods cannot be applied for bearing fault diagnosis with full confidence. Fault symptoms in such operating conditions cannot be easily extracted through usual measurement and signal processing techniques. A typical example is a bearing in heavy rolling mill with variable load and disturbance from other sources. In extremely slow speed operation, variation in speed due to speed controller transients or external disturbances (e.g., varying load) can be relatively high. To account for speed variation, instantaneous angular position instead of time is used as the base variable of signals for signal processing purposes. Even with time synchronous averaging (TSA) and well-established methods like envelope order analysis, rolling element faults in rolling element bearings cannot be easily identified during such operating conditions. In this article we propose to use order tracking on the envelope of the wavelet de-noised estimate of the short-duration angle synchronous averaged signal to diagnose faults in rolling element bearing operating under the stated special conditions. The proposed four-stage sequential signal processing method eliminates uncorrelated content, avoids signal smearing and exposes only the fault frequencies and its harmonics in the spectrum. We use experimental data1

Effect of using a treadmill workstation on performance of simulated office work tasks.

PubMed

John, Dinesh; Bassett, David; Thompson, Dixie; Fairbrother, Jeffrey; Baldwin, Debora

2009-09-01

Although using a treadmill workstation may change the sedentary nature of desk jobs, it is unknown if walking while working affects performance on office-work related tasks. To assess differences between seated and walking conditions on motor skills and cognitive function tests. Eleven males (24.6 +/- 3.5 y) and 9 females (27.0 +/- 3.9 y) completed a test battery to assess selective attention and processing speed, typing speed, mouse clicking/drag-and-drop speed, and GRE math and reading comprehension. Testing was performed under seated and walking conditions on 2 separate days using a counterbalanced, within subjects design. Participants did not have an acclimation period before the walking condition. Paired t tests (P < .05) revealed that in the seated condition, completion times were shorter for mouse clicking (26.6 +/- 3.0 vs. 28.2 +/- 2.5s) and drag-and-drop (40.3 +/- 4.2 vs. 43.9 +/- 2.5s) tests, typing speed was greater (40.2 +/- 9.1 vs. 36.9 +/- 10.2 adjusted words x min(-1)), and math scores were better (71.4 +/- 15.2 vs. 64.3 +/- 13.4%). There were no significant differences between conditions in selective attention and processing speed or in reading comprehension. Compared with the seated condition, treadmill walking caused a 6% to 11% decrease in measures of fine motor skills and math problem solving, but did not affect selective attention and processing speed or reading comprehension.

Non-contact Real-time heart rate measurements based on high speed circuit technology research

NASA Astrophysics Data System (ADS)

Wu, Jizhe; Liu, Xiaohua; Kong, Lingqin; Shi, Cong; Liu, Ming; Hui, Mei; Dong, Liquan; Zhao, Yuejin

2015-08-01

In recent years, morbidity and mortality of the cardiovascular or cerebrovascular disease, which threaten human health greatly, increased year by year. Heart rate is an important index of these diseases. To address this status, the paper puts forward a kind of simple structure, easy operation, suitable for large populations of daily monitoring non-contact heart rate measurement. In the method we use imaging equipment video sensitive areas. The changes of light intensity reflected through the image grayscale average. The light change is caused by changes in blood volume. We video the people face which include the sensitive areas (ROI), and use high-speed processing circuit to save the video as AVI format into memory. After processing the whole video of a period of time, we draw curve of each color channel with frame number as horizontal axis. Then get heart rate from the curve. We use independent component analysis (ICA) to restrain noise of sports interference, realized the accurate extraction of heart rate signal under the motion state. We design an algorithm, based on high-speed processing circuit, for face recognition and tracking to automatically get face region. We do grayscale average processing to the recognized image, get RGB three grayscale curves, and extract a clearer pulse wave curves through independent component analysis, and then we get the heart rate under the motion state. At last, by means of compare our system with Fingertip Pulse Oximeter, result show the system can realize a more accurate measurement, the error is less than 3 pats per minute.

Is there a hierarchy of social inferences? The likelihood and speed of inferring intentionality, mind, and personality.

PubMed

Malle, Bertram F; Holbrook, Jess

2012-04-01

People interpret behavior by making inferences about agents' intentionality, mind, and personality. Past research studied such inferences 1 at a time; in real life, people make these inferences simultaneously. The present studies therefore examined whether 4 major inferences (intentionality, desire, belief, and personality), elicited simultaneously in response to an observed behavior, might be ordered in a hierarchy of likelihood and speed. To achieve generalizability, the studies included a wide range of stimulus behaviors, presented them verbally and as dynamic videos, and assessed inferences both in a retrieval paradigm (measuring the likelihood and speed of accessing inferences immediately after they were made) and in an online processing paradigm (measuring the speed of forming inferences during behavior observation). Five studies provide evidence for a hierarchy of social inferences-from intentionality and desire to belief to personality-that is stable across verbal and visual presentations and that parallels the order found in developmental and primate research. (c) 2012 APA, all rights reserved.

Using the virtual reality device Oculus Rift for neuropsychological assessment of visual processing capabilities

PubMed Central

Foerster, Rebecca M.; Poth, Christian H.; Behler, Christian; Botsch, Mario; Schneider, Werner X.

2016-01-01

Neuropsychological assessment of human visual processing capabilities strongly depends on visual testing conditions including room lighting, stimuli, and viewing-distance. This limits standardization, threatens reliability, and prevents the assessment of core visual functions such as visual processing speed. Increasingly available virtual reality devices allow to address these problems. One such device is the portable, light-weight, and easy-to-use Oculus Rift. It is head-mounted and covers the entire visual field, thereby shielding and standardizing the visual stimulation. A fundamental prerequisite to use Oculus Rift for neuropsychological assessment is sufficient test-retest reliability. Here, we compare the test-retest reliabilities of Bundesen’s visual processing components (visual processing speed, threshold of conscious perception, capacity of visual working memory) as measured with Oculus Rift and a standard CRT computer screen. Our results show that Oculus Rift allows to measure the processing components as reliably as the standard CRT. This means that Oculus Rift is applicable for standardized and reliable assessment and diagnosis of elementary cognitive functions in laboratory and clinical settings. Oculus Rift thus provides the opportunity to compare visual processing components between individuals and institutions and to establish statistical norm distributions. PMID:27869220

Using the virtual reality device Oculus Rift for neuropsychological assessment of visual processing capabilities.

PubMed

Foerster, Rebecca M; Poth, Christian H; Behler, Christian; Botsch, Mario; Schneider, Werner X

2016-11-21

Neuropsychological assessment of human visual processing capabilities strongly depends on visual testing conditions including room lighting, stimuli, and viewing-distance. This limits standardization, threatens reliability, and prevents the assessment of core visual functions such as visual processing speed. Increasingly available virtual reality devices allow to address these problems. One such device is the portable, light-weight, and easy-to-use Oculus Rift. It is head-mounted and covers the entire visual field, thereby shielding and standardizing the visual stimulation. A fundamental prerequisite to use Oculus Rift for neuropsychological assessment is sufficient test-retest reliability. Here, we compare the test-retest reliabilities of Bundesen's visual processing components (visual processing speed, threshold of conscious perception, capacity of visual working memory) as measured with Oculus Rift and a standard CRT computer screen. Our results show that Oculus Rift allows to measure the processing components as reliably as the standard CRT. This means that Oculus Rift is applicable for standardized and reliable assessment and diagnosis of elementary cognitive functions in laboratory and clinical settings. Oculus Rift thus provides the opportunity to compare visual processing components between individuals and institutions and to establish statistical norm distributions.

Analysis of base fuze functioning of HESH ammunitions through high-speed photographic technique

NASA Astrophysics Data System (ADS)

Biswal, T. K.

2007-01-01

High-speed photography plays a major role in a Test Range where the direct access is possible through imaging in order to understand a dynamic process thoroughly and both qualitative and quantitative data are obtained thereafter through image processing and analysis. In one of the trials it was difficult to understand the performance of HESH ammunitions on rolled homogeneous armour. There was no consistency in scab formation even though all other parameters like propellant charge mass, charge temperature, impact velocity etc are maintained constant. To understand the event thoroughly high-speed photography was deployed to have a frontal view of the total process. Clear information of shell impact, embedding of HE propellant on armour and base fuze initiation are obtained. In case of scab forming rounds these three processes are clearly observed in sequence. However in non-scab ones base fuze is initiated before the completion of the embedding process resulting non-availability of threshold thrust on to the armour to cause scab. This has been revealed in two rounds where there was a failure of scab formation. As a quantitative measure, fuze delay was calculated for each round and there after premature functioning of base fuze was ascertained in case of non-scab rounds. Such potency of high-speed photography has been depicted in details in this paper.

High-speed single-shot optical focusing through dynamic scattering media with full-phase wavefront shaping.

PubMed

Hemphill, Ashton S; Shen, Yuecheng; Liu, Yan; Wang, Lihong V

2017-11-27

In biological applications, optical focusing is limited by the diffusion of light, which prevents focusing at depths greater than ∼1 mm in soft tissue. Wavefront shaping extends the depth by compensating for phase distortions induced by scattering and thus allows for focusing light through biological tissue beyond the optical diffusion limit by using constructive interference. However, due to physiological motion, light scattering in tissue is deterministic only within a brief speckle correlation time. In in vivo tissue, this speckle correlation time is on the order of milliseconds, and so the wavefront must be optimized within this brief period. The speed of digital wavefront shaping has typically been limited by the relatively long time required to measure and display the optimal phase pattern. This limitation stems from the low speeds of cameras, data transfer and processing, and spatial light modulators. While binary-phase modulation requiring only two images for the phase measurement has recently been reported, most techniques require at least three frames for the full-phase measurement. Here, we present a full-phase digital optical phase conjugation method based on off-axis holography for single-shot optical focusing through scattering media. By using off-axis holography in conjunction with graphics processing unit based processing, we take advantage of the single-shot full-phase measurement while using parallel computation to quickly reconstruct the phase map. With this system, we can focus light through scattering media with a system latency of approximately 9 ms, on the order of the in vivo speckle correlation time.

High-speed single-shot optical focusing through dynamic scattering media with full-phase wavefront shaping

NASA Astrophysics Data System (ADS)

Hemphill, Ashton S.; Shen, Yuecheng; Liu, Yan; Wang, Lihong V.

2017-11-01

In biological applications, optical focusing is limited by the diffusion of light, which prevents focusing at depths greater than ˜1 mm in soft tissue. Wavefront shaping extends the depth by compensating for phase distortions induced by scattering and thus allows for focusing light through biological tissue beyond the optical diffusion limit by using constructive interference. However, due to physiological motion, light scattering in tissue is deterministic only within a brief speckle correlation time. In in vivo tissue, this speckle correlation time is on the order of milliseconds, and so the wavefront must be optimized within this brief period. The speed of digital wavefront shaping has typically been limited by the relatively long time required to measure and display the optimal phase pattern. This limitation stems from the low speeds of cameras, data transfer and processing, and spatial light modulators. While binary-phase modulation requiring only two images for the phase measurement has recently been reported, most techniques require at least three frames for the full-phase measurement. Here, we present a full-phase digital optical phase conjugation method based on off-axis holography for single-shot optical focusing through scattering media. By using off-axis holography in conjunction with graphics processing unit based processing, we take advantage of the single-shot full-phase measurement while using parallel computation to quickly reconstruct the phase map. With this system, we can focus light through scattering media with a system latency of approximately 9 ms, on the order of the in vivo speckle correlation time.

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.

Insights from field observations into controls on flow front speed in submarine sediment flows

NASA Astrophysics Data System (ADS)

Heerema, C.; Talling, P.; Cartigny, M.; Paull, C. K.; Gwiazda, R.; Clare, M. A.; Parsons, D. R.; Xu, J.; Simmons, S.; Maier, K. L.; Chapplow, N.; Gales, J. A.; McGann, M.; Barry, J.; Lundsten, E. M.; Anderson, K.; O'Reilly, T. C.; Rosenberger, K. J.; Sumner, E. J.; Stacey, C.

2017-12-01

Seafloor avalanches of sediment called turbidity currents are one of the most important processes for moving sediment across our planet. Only rivers carry comparable amounts of sediment across such large areas. Here we present some of the first detailed monitoring of these underwater flows that is being undertaken at a series of test sites. We seek to understand the factors that determine flow front speed, and how that speed varies with distance. This frontal speed is particularly important for predicting flow runout, and how the power of these hazardous flows varies with distance. First, we consider unusually detailed measurements of flow front speed defined by transit times between moorings and other tracked objects placed on the floor of Monterey Canyon offshore California in 2016-17. These measurements are then compared to flow front speeds measured using multiple moorings in Bute Inlet, British Columbia in 2016; and by cable breaks in Gaoping Canyon offshore Taiwan in 2006 and 2009. We seek to understand how flow front velocity is related to seafloor gradient, flow front thickness and density. It appears that the spatial evolution of frontal speed is similar in multiple flows, although their peak frontal velocities vary. Flow front velocity tends to increase rapidly initially before declining rather gradually over tens or even hundreds of kilometres. It has been proposed that submarine flows will exist in one of two states; either eroding and accelerating, or depositing sediment and dissipating. We conclude by discussing the implications of this global compilation of flow front velocities for understanding submarine flow behaviour.

Sentence Processing Factors in Adults with Specific Language Impairment

ERIC Educational Resources Information Center

Poll, Gerard H.

2012-01-01

Sentence imitation effectively discriminates between adults with and without specific language impairment (SLI). Little is known, however, about the factors that result in performance differences. This study evaluated the effects of working memory, processing speed, and argument status on sentence imitation. Working memory was measured by both a…

On Some Stopping Times of Citation Processes. From Theory to Indicators.

ERIC Educational Resources Information Center

Glanzel, Wolfgang

1992-01-01

Proposes a new measure of the citation speed of scientific publications based on a stopping time approach. The stochastic process approach in bibliometrics is described, mean response time (MRT) is discussed, harmonic mean response time (HMRT) is explained, and examples are given. (six references) (LRW)

75 FR 25927 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-10

... qualification process as an important tool for the assessment of vehicle performance. These simulations are... qualification process, simulations would be conducted using both a measured track geometry segment... on the results of simulation studies designed to identify track geometry irregularities associated...

A Tablet for Healthy Ageing: The Effect of a Tablet Computer Training Intervention on Cognitive Abilities in Older Adults.

PubMed

Vaportzis, Eleftheria; Martin, Mike; Gow, Alan J

2017-08-01

To test the efficacy of a tablet computer training intervention to improve cognitive abilities of older adults. Prospective randomized controlled trial. Community-based aging intervention study, Edinburgh, UK. Forty-eight healthy older adults aged 65 to 76 years were recruited at baseline with no or minimal tablet experience; 43 completed follow-up testing. Twenty-two participants attended a weekly 2-hour class for 10 weeks during which they learned how to use a tablet and various applications on it. A battery of cognitive tests from the WAIS-IV measuring the domains of Verbal Comprehension, Perceptual Processing, Working Memory, and Processing Speed, as well as health, psychological, and well-being measures. A 2 × 2 mixed model ANOVA suggested that the tablet intervention group (N = 22) showed greater improvements in Processing Speed (η 2  = 0.10) compared with controls (N = 21), but did not differ in Verbal Comprehension, Perceptual Processing, or Working Memory (η 2 ranged from -0.03 to 0.04). Engagement in a new mentally challenging activity (tablet training) was associated with improved processing speed. Acquiring skills in later life, including those related to adopting new technologies, may therefore have the potential to reduce or delay cognitive changes associated with ageing. It is important to understand how the development of these skills might further facilitate everyday activities, and also improve older adults' quality of life. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Comparing depression screening tools in persons with multiple sclerosis (MS).

PubMed

Hanna, Joshua; Santo, Jonathan B; Blair, Mervin; Smolewska, Kathy; Warriner, Erin; Morrow, Sarah A

2017-02-01

Depression is more common among persons with multiple sclerosis (MS) than the general population. Depression in MS is associated with reduced quality of life, transition to unemployment, and cognitive impairment. Two proposed screening measures for depression in MS populations are the Hospital Anxiety and Depression Scale (HADS) and the Beck Depression Inventory-Fast Screen (BDI-FS). Our objective was to compared the associations of the BDI-FS and the HADS-D scores with history of depressive symptoms, fatigue, and functional outcomes to determine the differential clinical utility of these screening measures among persons with MS. We reviewed charts of 133 persons with MS for demographic information; scores on the HADS, BDI-FS, a fatigue measure, and a processing speed measure; and employment status. Structural equation modeling results indicated the HADS-D predicted employment status, disability status, and processing speed more effectively than did the BDI-FS, whereas both measures predicted fatigue. This study suggests the HADS-D is more effective than the BDI-FS in predicting functional outcomes known to be associated with depression among persons with MS. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Design of quantum efficiency measurement system for variable doping GaAs photocathode

NASA Astrophysics Data System (ADS)

Chen, Liang; Yang, Kai; Liu, HongLin; Chang, Benkang

2008-03-01

To achieve high quantum efficiency and good stability has been a main direction to develop GaAs photocathode recently. Through early research, we proved that variable doping structure is executable and practical, and has great potential. In order to optimize variable doping GaAs photocathode preparation techniques and study the variable doping theory deeply, a real-time quantum efficiency measurement system for GaAs Photocathode has been designed. The system uses FPGA (Field-programmable gate array) device, and high speed A/D converter to design a high signal noise ratio and high speed data acquisition card. ARM (Advanced RISC Machines) core processor s3c2410 and real-time embedded system are used to obtain and show measurement results. The measurement precision of photocurrent could reach 1nA, and measurement range of spectral response curve is within 400~1000nm. GaAs photocathode preparation process can be real-time monitored by using this system. This system could easily be added other functions to show the physic variation of photocathode during the preparation process more roundly in the future.

Determination of combustion parameters using engine crankshaft speed

NASA Astrophysics Data System (ADS)

Taglialatela, F.; Lavorgna, M.; Mancaruso, E.; Vaglieco, B. M.

2013-07-01

Electronic engine controls based on real time diagnosis of combustion process can significantly help in complying with the stricter and stricter regulations on pollutants emissions and fuel consumption. The most important parameter for the evaluation of combustion quality in internal combustion engines is the in-cylinder pressure, but its direct measurement is very expensive and involves an intrusive approach to the cylinder. Previous researches demonstrated the direct relationship existing between in-cylinder pressure and engine crankshaft speed and several authors tried to reconstruct the pressure cycle on the basis of the engine speed signal. In this paper we propose the use of a Multi-Layer Perceptron neural network to model the relationship between the engine crankshaft speed and some parameters derived from the in-cylinder pressure cycle. This allows to have a non-intrusive estimation of cylinder pressure and a real time evaluation of combustion quality. The structure of the model and the training procedure is outlined in the paper. A possible combustion controller using the information extracted from the crankshaft speed information is also proposed. The application of the neural network model is demonstrated on a single-cylinder spark ignition engine tested in a wide range of speeds and loads. Results confirm that a good estimation of some combustion pressure parameters can be obtained by means of a suitable processing of crankshaft speed signal.

Can Training Enhance Face Cognition Abilities in Middle-Aged Adults?

PubMed Central

Dolzycka, Dominika; Herzmann, Grit; Sommer, Werner; Wilhelm, Oliver

2014-01-01

Face cognition is a crucial skill for social interaction and shows large individual differences in healthy adults, suggesting a possibility for improvement in some. We developed and tested specific training procedures for the accuracy of face memory and the speed of face cognition. Two groups each of 20 healthy middle-aged trainees practiced for 29 daily sessions of 15 minutes duration with different computerized home-based training procedures. In addition, 20 matched and 59 non-matched controls were included. Face cognition speed training enhanced performance during the training and transferred to the latent factor level as measured in a pre-post comparison. Persistence of the training effect was evidenced at the manifest level after three months. However, the training procedure influenced the speed of processing object stimuli to the same extent as face stimuli and therefore seems to have affected a more general ability of processing complex visual stimuli and not only faces. No effects of training on the accuracy of face memory were found. This study demonstrates that face-specific abilities may be hard to improve but also shows the plasticity of the speed of processing complex visual stimuli – for the first time in middle-aged, normal adults. PMID:24632743

Exploring Expressive Vocabulary Variability in Two-Year-Olds: The Role of Working Memory

ERIC Educational Resources Information Center

Newbury, Jayne; Klee, Thomas; Stokes, Stephanie F.; Moran, Catherine

2015-01-01

Purpose: This study explored whether measures of working memory ability contribute to the wide variation in 2-year-olds' expressive vocabulary skills. Method: Seventy-nine children (aged 24-30 months) were assessed by using standardized tests of vocabulary and visual cognition, a processing speed measure, and behavioral measures of verbal working…

High-speed mixture fraction and temperature imaging of pulsed, turbulent fuel jets auto-igniting in high-temperature, vitiated co-flows

NASA Astrophysics Data System (ADS)

Papageorge, Michael J.; Arndt, Christoph; Fuest, Frederik; Meier, Wolfgang; Sutton, Jeffrey A.

2014-07-01

In this manuscript, we describe an experimental approach to simultaneously measure high-speed image sequences of the mixture fraction and temperature fields during pulsed, turbulent fuel injection into a high-temperature, co-flowing, and vitiated oxidizer stream. The quantitative mixture fraction and temperature measurements are determined from 10-kHz-rate planar Rayleigh scattering and a robust data processing methodology which is accurate from fuel injection to the onset of auto-ignition. In addition, the data processing is shown to yield accurate temperature measurements following ignition to observe the initial evolution of the "burning" temperature field. High-speed OH* chemiluminescence (CL) was used to determine the spatial location of the initial auto-ignition kernel. In order to ensure that the ignition kernel formed inside of the Rayleigh scattering laser light sheet, OH* CL was observed in two viewing planes, one near-parallel to the laser sheet and one perpendicular to the laser sheet. The high-speed laser measurements are enabled through the use of the unique high-energy pulse burst laser system which generates long-duration bursts of ultra-high pulse energies at 532 nm (>1 J) suitable for planar Rayleigh scattering imaging. A particular focus of this study was to characterize the fidelity of the measurements both in the context of the precision and accuracy, which includes facility operating and boundary conditions and measurement of signal-to-noise ratio (SNR). The mixture fraction and temperature fields deduced from the high-speed planar Rayleigh scattering measurements exhibited SNR values greater than 100 at temperatures exceeding 1,300 K. The accuracy of the measurements was determined by comparing the current mixture fraction results to that of "cold", isothermal, non-reacting jets. All profiles, when properly normalized, exhibited self-similarity and collapsed upon one another. Finally, example mixture fraction, temperature, and OH* emission sequences are presented for a variety for fuel and vitiated oxidizer combinations. For all cases considered, auto-ignition occurred at the periphery of the fuel jet, under very "lean" conditions, where the local mixture fraction was less than the stoichiometric mixture fraction ( ξ < ξ s). Furthermore, the ignition kernel formed in regions of low scalar dissipation rate, which agrees with previous results from direct numerical simulations.

Speed and accuracy of dyslexic versus typical word recognition: an eye-movement investigation

PubMed Central

Kunert, Richard; Scheepers, Christoph

2014-01-01

Developmental dyslexia is often characterized by a dual deficit in both word recognition accuracy and general processing speed. While previous research into dyslexic word recognition may have suffered from speed-accuracy trade-off, the present study employed a novel eye-tracking task that is less prone to such confounds. Participants (10 dyslexics and 12 controls) were asked to look at real word stimuli, and to ignore simultaneously presented non-word stimuli, while their eye-movements were recorded. Improvements in word recognition accuracy over time were modeled in terms of a continuous non-linear function. The words' rhyme consistency and the non-words' lexicality (unpronounceable, pronounceable, pseudohomophone) were manipulated within-subjects. Speed-related measures derived from the model fits confirmed generally slower processing in dyslexics, and showed a rhyme consistency effect in both dyslexics and controls. In terms of overall error rate, dyslexics (but not controls) performed less accurately on rhyme-inconsistent words, suggesting a representational deficit for such words in dyslexics. Interestingly, neither group showed a pseudohomophone effect in speed or accuracy, which might call the task-independent pervasiveness of this effect into question. The present results illustrate the importance of distinguishing between speed- vs. accuracy-related effects for our understanding of dyslexic word recognition. PMID:25346708

Comparison of EEG propagation speeds under emotional stimuli on smartphone between the different anxiety states

PubMed Central

Asakawa, Tetsuya; Muramatsu, Ayumi; Hayashi, Takuto; Urata, Tatsuya; Taya, Masato; Mizuno-Matsumoto, Yuko

2014-01-01

The current study evaluated the effect of different anxiety states on information processing as measured by an electroencephalography (EEG) using emotional stimuli on a smartphone. Twenty-three healthy subjects were assessed for their anxiety states using The State Trait Anxiety Inventory (STAI) and divided into two groups: low anxiety (I, II) or high anxiety (III and IV, V). An EEG was performed while the participant was presented with emotionally laden audiovisual stimuli (resting, pleasant, and unpleasant sessions) and emotionally laden sentence stimuli (pleasant sentence, unpleasant sentence sessions) and EEG data was analyzed using propagation speed analysis. The propagation speed of the low anxiety group at the medial coronal for resting stimuli for all time segments was higher than those of high anxiety group. The low anxiety group propagation speeds at the medial sagittal for unpleasant stimuli in the 0–30 and 60–150 s time frames were higher than those of high anxiety group. The propagation speeds at 150 s for all stimuli in the low anxiety group were significantly higher than the correspondent propagation speeds of the high anxiety group. These events suggest that neural information processes concerning emotional stimuli differ based on current anxiety state. PMID:25540618

Thermo-mechanical behavior and structure of melt blown shape-memory polyurethane nonwovens.

PubMed

Safranski, David L; Boothby, Jennifer M; Kelly, Cambre N; Beatty, Kyle; Lakhera, Nishant; Frick, Carl P; Lin, Angela; Guldberg, Robert E; Griffis, Jack C

2016-09-01

New processing methods for shape-memory polymers allow for tailoring material properties for numerous applications. Shape-memory nonwovens have been previously electrospun, but melt blow processing has yet to be evaluated. In order to determine the process parameters affecting shape-memory behavior, this study examined the effect of air pressure and collector speed on the mechanical behavior and shape-recovery of shape-memory polyurethane nonwovens. Mechanical behavior was measured by dynamic mechanical analysis and tensile testing, and shape-recovery was measured by unconstrained and constrained recovery. Microstructure changes throughout the shape-memory cycle were also investigated by micro-computed tomography. It was found that increasing collector speed increases elastic modulus, ultimate strength and recovery stress of the nonwoven, but collector speed does not affect the failure strain or unconstrained recovery. Increasing air pressure decreases the failure strain and increases rubbery modulus and unconstrained recovery, but air pressure does not influence recovery stress. It was also found that during the shape-memory cycle, the connectivity density of the fibers upon recovery does not fully return to the initial values, accounting for the incomplete shape-recovery seen in shape-memory nonwovens. With these parameter to property relationships identified, shape-memory nonwovens can be more easily manufactured and tailored for specific applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adjusting an electron beam for drilling

NASA Technical Reports Server (NTRS)

Childress, C. L.

1980-01-01

Reticle contains two concentric circles: inner circle insures beam circularity and outer circle is guide to prevent beam from cutting workpiece clamp. Precise measurement of beam and clamp are required with old reticle. New reticle speeds up electron-beam drilling process by eliminating need to rotate eyepiece to make measurements against reticle scale.

Age-related decline in cognitive control: the role of fluid intelligence and processing speed

PubMed Central

2014-01-01

Background Research on cognitive control suggests an age-related decline in proactive control abilities whereas reactive control seems to remain intact. However, the reason of the differential age effect on cognitive control efficiency is still unclear. This study investigated the potential influence of fluid intelligence and processing speed on the selective age-related decline in proactive control. Eighty young and 80 healthy older adults were included in this study. The participants were submitted to a working memory recognition paradigm, assessing proactive and reactive cognitive control by manipulating the interference level across items. Results Repeated measures ANOVAs and hierarchical linear regressions indicated that the ability to appropriately use cognitive control processes during aging seems to be at least partially affected by the amount of available cognitive resources (assessed by fluid intelligence and processing speed abilities). Conclusions This study highlights the potential role of cognitive resources on the selective age-related decline in proactive control, suggesting the importance of a more exhaustive approach considering the confounding variables during cognitive control assessment. PMID:24401034

Is rapid automatized naming related to reading and mathematics for the same reason(s)? A follow-up study from kindergarten to Grade 1.

PubMed

Georgiou, George K; Tziraki, Niki; Manolitsis, George; Fella, Argyro

2013-07-01

We examined (a) what rapid automatized naming (RAN) components (articulation time and/or pause time) predict reading and mathematics ability and (b) what processing skills involved in RAN (speed of processing, response inhibition, working memory, and/or phonological awareness) may explain its relationship with reading and mathematics. A sample of 72 children were followed from the beginning of kindergarten until the end of Grade 1 and were assessed on measures of RAN, general cognitive ability, speed of processing, attention, working memory, phonological awareness, reading, and mathematics. The results indicated that pause time was the critical component in both the RAN-reading and RAN-mathematics relationships and that it shared most of its predictive variance in reading and mathematics with speed of processing and working memory. Our findings further suggested that, unlike the relationship between RAN and reading fluency in Grade 1, there is nothing in the RAN task that is uniquely related to math. Copyright © 2013 Elsevier Inc. All rights reserved.

Geometry characteristics modeling and process optimization in coaxial laser inside wire cladding

NASA Astrophysics Data System (ADS)

Shi, Jianjun; Zhu, Ping; Fu, Geyan; Shi, Shihong

2018-05-01

Coaxial laser inside wire cladding method is very promising as it has a very high efficiency and a consistent interaction between the laser and wire. In this paper, the energy and mass conservation law, and the regression algorithm are used together for establishing the mathematical models to study the relationship between the layer geometry characteristics (width, height and cross section area) and process parameters (laser power, scanning velocity and wire feeding speed). At the selected parameter ranges, the predicted values from the models are compared with the experimental measured results, and there is minor error existing, but they reflect the same regularity. From the models, it is seen the width of the cladding layer is proportional to both the laser power and wire feeding speed, while it firstly increases and then decreases with the increasing of the scanning velocity. The height of the cladding layer is proportional to the scanning velocity and feeding speed and inversely proportional to the laser power. The cross section area increases with the increasing of feeding speed and decreasing of scanning velocity. By using the mathematical models, the geometry characteristics of the cladding layer can be predicted by the known process parameters. Conversely, the process parameters can be calculated by the targeted geometry characteristics. The models are also suitable for multi-layer forming process. By using the optimized process parameters calculated from the models, a 45 mm-high thin-wall part is formed with smooth side surfaces.

High-speed limnology: using advanced sensors to investigate spatial variability in biogeochemistry and hydrology.

PubMed

Crawford, John T; Loken, Luke C; Casson, Nora J; Smith, Colin; Stone, Amanda G; Winslow, Luke A

2015-01-06

Advanced sensor technology is widely used in aquatic monitoring and research. Most applications focus on temporal variability, whereas spatial variability has been challenging to document. We assess the capability of water chemistry sensors embedded in a high-speed water intake system to document spatial variability. This new sensor platform continuously samples surface water at a range of speeds (0 to >45 km h(-1)) resulting in high-density, mesoscale spatial data. These novel observations reveal previously unknown variability in physical, chemical, and biological factors in streams, rivers, and lakes. By combining multiple sensors into one platform, we were able to detect terrestrial-aquatic hydrologic connections in a small dystrophic lake, to infer the role of main-channel vs backwater nutrient processing in a large river and to detect sharp chemical changes across aquatic ecosystem boundaries in a stream/lake complex. Spatial sensor data were verified in our examples by comparing with standard lab-based measurements of selected variables. Spatial fDOM data showed strong correlation with wet chemistry measurements of DOC, and optical NO3 concentrations were highly correlated with lab-based measurements. High-frequency spatial data similar to our examples could be used to further understand aquatic biogeochemical fluxes, ecological patterns, and ecosystem processes, and will both inform and benefit from fixed-site data.

High-speed limnology: Using advanced sensors to investigate spatial variability in biogeochemistry and hydrology

USGS Publications Warehouse

Crawford, John T.; Loken, Luke C.; Casson, Nora J.; Smith, Collin; Stone, Amanda G.; Winslow, Luke A.

2015-01-01

Advanced sensor technology is widely used in aquatic monitoring and research. Most applications focus on temporal variability, whereas spatial variability has been challenging to document. We assess the capability of water chemistry sensors embedded in a high-speed water intake system to document spatial variability. This new sensor platform continuously samples surface water at a range of speeds (0 to >45 km h–1) resulting in high-density, mesoscale spatial data. These novel observations reveal previously unknown variability in physical, chemical, and biological factors in streams, rivers, and lakes. By combining multiple sensors into one platform, we were able to detect terrestrial–aquatic hydrologic connections in a small dystrophic lake, to infer the role of main-channel vs backwater nutrient processing in a large river and to detect sharp chemical changes across aquatic ecosystem boundaries in a stream/lake complex. Spatial sensor data were verified in our examples by comparing with standard lab-based measurements of selected variables. Spatial fDOM data showed strong correlation with wet chemistry measurements of DOC, and optical NO3 concentrations were highly correlated with lab-based measurements. High-frequency spatial data similar to our examples could be used to further understand aquatic biogeochemical fluxes, ecological patterns, and ecosystem processes, and will both inform and benefit from fixed-site data.

Pathways From Toddler Information Processing to Adolescent Lexical Proficiency.

PubMed

Rose, Susan A; Feldman, Judith F; Jankowski, Jeffery J

2015-01-01

This study examined the relation of 3-year core information-processing abilities to lexical growth and development. The core abilities covered four domains-memory, representational competence (cross-modal transfer), processing speed, and attention. Lexical proficiency was assessed at 3 and 13 years with the Peabody Picture Vocabulary Test (PPVT) and verbal fluency. The sample (N = 128) consisted of 43 preterms (< 1750 g) and 85 full-terms. Structural equation modeling indicated concurrent relations of toddler information processing and language proficiency and, independent of stability in language, direct predictive links between (a) 3-year cross-modal ability and 13-year PPVT and (b) 3-year processing speed and both 13-year measures, PPVT and verbal fluency. Thus, toddler information processing was related to growth in lexical proficiency from 3 to 13 years. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

Thermographic Measurements of the Commercial Laser Powder Bed Fusion Process at NIST.

PubMed

Lane, Brandon; Moylan, Shawn; Whitenton, Eric; Ma, Li

2016-01-01

Measurement of the high-temperature melt pool region in the laser powder bed fusion (L-PBF) process is a primary focus of researchers to further understand the dynamic physics of the heating, melting, adhesion, and cooling which define this commercially popular additive manufacturing process. This paper will detail the design, execution, and results of high speed, high magnification in-situ thermographic measurements conducted at the National Institute of Standards and Technology (NIST) focusing on the melt pool region of a commercial L-PBF process. Multiple phenomena are observed including plasma plume and hot particle ejection from the melt region. The thermographic measurement process will be detailed with emphasis on the 'measurability' of observed phenomena and the sources of measurement uncertainty. Further discussion will relate these thermographic results to other efforts at NIST towards L-PBF process finite element simulation and development of in-situ sensing and control methodologies.

Quality Control Methodology Of A Surface Wind Observational Database In North Eastern North America

NASA Astrophysics Data System (ADS)

Lucio-Eceiza, Etor E.; Fidel González-Rouco, J.; Navarro, Jorge; Conte, Jorge; Beltrami, Hugo

2016-04-01

This work summarizes the design and application of a Quality Control (QC) procedure for an observational surface wind database located in North Eastern North America. The database consists of 526 sites (486 land stations and 40 buoys) with varying resolutions of hourly, 3 hourly and 6 hourly data, compiled from three different source institutions with uneven measurement units and changing measuring procedures, instrumentation and heights. The records span from 1953 to 2010. The QC process is composed of different phases focused either on problems related with the providing source institutions or measurement errors. The first phases deal with problems often related with data recording and management: (1) compilation stage dealing with the detection of typographical errors, decoding problems, site displacements and unification of institutional practices; (2) detection of erroneous data sequence duplications within a station or among different ones; (3) detection of errors related with physically unrealistic data measurements. The last phases are focused on instrumental errors: (4) problems related with low variability, placing particular emphasis on the detection of unrealistic low wind speed records with the help of regional references; (5) high variability related erroneous records; (6) standardization of wind speed record biases due to changing measurement heights, detection of wind speed biases on week to monthly timescales, and homogenization of wind direction records. As a result, around 1.7% of wind speed records and 0.4% of wind direction records have been deleted, making a combined total of 1.9% of removed records. Additionally, around 15.9% wind speed records and 2.4% of wind direction data have been also corrected.

Visual motion direction is represented in population-level neural response as measured by magnetoencephalography.

PubMed

Kaneoke, Y; Urakawa, T; Kakigi, R

2009-05-19

We investigated whether direction information is represented in the population-level neural response evoked by the visual motion stimulus, as measured by magnetoencephalography. Coherent motions with varied speed, varied direction, and different coherence level were presented using random dot kinematography. Peak latency of responses to motion onset was inversely related to speed in all directions, as previously reported, but no significant effect of direction on latency changes was identified. Mutual information entropy (IE) calculated using four-direction response data increased significantly (>2.14) after motion onset in 41.3% of response data and maximum IE was distributed at approximately 20 ms after peak response latency. When response waveforms showing significant differences (by multivariate discriminant analysis) in distribution of the three waveform parameters (peak amplitude, peak latency, and 75% waveform width) with stimulus directions were analyzed, 87 waveform stimulus directions (80.6%) were correctly estimated using these parameters. Correct estimation rate was unaffected by stimulus speed, but was affected by coherence level, even though both speed and coherence affected response amplitude similarly. Our results indicate that speed and direction of stimulus motion are represented in the distinct properties of a response waveform, suggesting that the human brain processes speed and direction separately, at least in part.

Vibration-based angular speed estimation for multi-stage wind turbine gearboxes

NASA Astrophysics Data System (ADS)

Peeters, Cédric; Leclère, Quentin; Antoni, Jérôme; Guillaume, Patrick; Helsen, Jan

2017-05-01

Most processing tools based on frequency analysis of vibration signals are only applicable for stationary speed regimes. Speed variation causes the spectral content to smear, which encumbers most conventional fault detection techniques. To solve the problem of non-stationary speed conditions, the instantaneous angular speed (IAS) is estimated. Wind turbine gearboxes however are typically multi-stage gearboxes, consisting of multiple shafts, rotating at different speeds. Fitting a sensor (e.g. a tachometer) to every single stage is not always feasible. As such there is a need to estimate the IAS of every single shaft based on the vibration signals measured by the accelerometers. This paper investigates the performance of the multi-order probabilistic approach for IAS estimation on experimental case studies of wind turbines. This method takes into account the meshing orders of the gears present in the system and has the advantage that a priori it is not necessary to associate harmonics with a certain periodic mechanical event, which increases the robustness of the method. It is found that the MOPA has the potential to easily outperform standard band-pass filtering techniques for speed estimation. More knowledge of the gearbox kinematics is beneficial for the MOPA performance, but even with very little knowledge about the meshing orders, the MOPA still performs sufficiently well to compete with the standard speed estimation techniques. This observation is proven on two different data sets, both originating from vibration measurements on the gearbox housing of a wind turbine.

The implementation of depth measurement and related algorithms based on binocular vision in embedded AM5728

NASA Astrophysics Data System (ADS)

Deng, Zhiwei; Li, Xicai; Shi, Junsheng; Huang, Xiaoqiao; Li, Feiyan

2018-01-01

Depth measurement is the most basic measurement in various machine vision, such as automatic driving, unmanned aerial vehicle (UAV), robot and so on. And it has a wide range of use. With the development of image processing technology and the improvement of hardware miniaturization and processing speed, real-time depth measurement using dual cameras has become a reality. In this paper, an embedded AM5728 and the ordinary low-cost dual camera is used as the hardware platform. The related algorithms of dual camera calibration, image matching and depth calculation have been studied and implemented on the hardware platform, and hardware design and the rationality of the related algorithms of the system are tested. The experimental results show that the system can realize simultaneous acquisition of binocular images, switching of left and right video sources, display of depth image and depth range. For images with a resolution of 640 × 480, the processing speed of the system can be up to 25 fps. The experimental results show that the optimal measurement range of the system is from 0.5 to 1.5 meter, and the relative error of the distance measurement is less than 5%. Compared with the PC, ARM11 and DMCU hardware platforms, the embedded AM5728 hardware is good at meeting real-time depth measurement requirements in ensuring the image resolution.

Photo-Machining of Semiconductor Related Materials with Femtosecond Laser Ablation and Characterization of Its Properties

NASA Astrophysics Data System (ADS)

Yokotani, Atushi; Mizuno, Toshio; Mukumoto, Toru; Kawahara, Kousuke; Ninomiya, Takahumi; Sawada, Hiroshi; Kurosawa, Kou

We have analyzed the drilling process with femtosecond laser on the silicon surface in order to investigate a degree of thermal effect during the dicing process of the very thin silicon substrate. A regenerative amplified Ti:Al2O3 laser (E= 30˜500 μJ/pulse, τ= 200 fs, λ= 780 nm, f= 10 Hz) was used and focused onto a 50 μm-thick silicon sample. ICCD (Intensified Charge coupled Device) camera with a high-speed gate of 5 ns was utilized to take images of processing hole. First, we investigated the dependence of laser energy on the speed of the formation of the drilled hole. As a result, it was found that the lager the energy, the slower the speed of the formation under the minimum hole was obtained. Consequently, in the case of defocused condition, even when the smaller the energy density was used, the very slow speed of formation and the much lager thermal effects are simultaneously observed. So we can say that the degree of the thermal effects is not simply related to energy density of the laser but strongly related to the speed of the formation, which can be measured by the ICCD camera. The similar tendency was also obtained for other materials, which are important for the fabrication of ICs (Al, Cu, SiO2 and acrylic resin).

Noncontact Measurement Of Sizes And Eccentricities Of Holes

NASA Technical Reports Server (NTRS)

Chern, Engmin J.

1993-01-01

Semiautomatic eddy-current-probe apparatus makes noncontact measurements of nominally round holes in electrically conductive specimens and processes measurement data into diameters and eccentricities of holes. Includes x-y translation platform, which holds specimen and moves it horizontally. Probe mounted on probe scanner, positioning probe along vertical (z) direction and rotates probe about vertical axis at preset low speed. Eddy-current sensing coil mounted in side of probe near tip. As probe rotates, impedance analyzer measures electrical impedance (Z) of coil as function of instantaneous rotation angle. Translation and rotation mechanisms and impedance analyzer controlled by computer, which also processes impedance-measurement data.

Fluid Merging Viscosity Measurement (FMVM) Experiment on the International Space Station

NASA Technical Reports Server (NTRS)

Antar, Basil N.; Ethridge, Edwin; Lehman, Daniel; Kaukler, William

2007-01-01

The concept of using low gravity experimental data together with fluid dynamical numerical simulations for measuring the viscosity of highly viscous liquids was recently validated on the International Space Station (ISS). After testing the proof of concept for this method with parabolic flight experiments, an ISS experiment was proposed and later conducted onboard the ISS in July, 2004 and subsequently in May of 2005. In that experiment a series of two liquid drops were brought manually together until they touched and then were allowed to merge under the action of capillary forces alone. The merging process was recorded visually in order to measure the contact radius speed as the merging proceeded. Several liquids were tested and for each liquid several drop diameters were used. It has been shown that when the coefficient of surface tension for the liquid is known, the contact radius speed can then determine the coefficient of viscosity for that liquid. The viscosity is determined by fitting the experimental speed to theoretically calculated contact radius speed for the same experimental parameters. Experimental and numerical results will be presented in which the viscosity of different highly viscous liquids were determined, to a high degree of accuracy, using this technique.

Revisiting the Relations between the WJ-IV Measures of Cattell-Horn-Carroll (CHC) Cognitive Abilities and Reading Achievement during the School-Age Years

ERIC Educational Resources Information Center

Cormier, Damien C.; McGrew, Kevin S.; Bulut, Okan; Funamoto, Allyson

2017-01-01

This study examined associations between broad cognitive abilities (Fluid Reasoning [Gf], Short-Term Working Memory [Gwm], Long-Term Storage and Retrieval [Glr], Processing Speed [Gs], Comprehension-Knowledge [Gc], Visual Processing [Gv], and Auditory Processing [Ga]) and reading achievement (Basic Reading Skills, Reading Rate, Reading Fluency,…

Using Field and Satellite Measurements to Improve Snow and Riming Processes in Cloud Resolving Models

NASA Technical Reports Server (NTRS)

Colle, Brian A.; Molthan, Andrew L.

2013-01-01

The representation of clouds in climate and weather models is a driver in forecast uncertainty. Cloud microphysics parameterizations are challenged by having to represent a diverse range of ice species. Key characteristics of predicted ice species include habit and fall speed, and complex interactions that result from mixed-phased processes like riming. Our proposed activity leverages Global Precipitation Measurement (GPM) Mission ground validation studies to improve parameterizations

Development of Multi-perspective Diagnostics and Analysis Algorithms with Applications to Subsonic and Supersonic Combustors

NASA Astrophysics Data System (ADS)

Wickersham, Andrew Joseph

There are two critical research needs for the study of hydrocarbon combustion in high speed flows: 1) combustion diagnostics with adequate temporal and spatial resolution, and 2) mathematical techniques that can extract key information from large datasets. The goal of this work is to address these needs, respectively, by the use of high speed and multi-perspective chemiluminescence and advanced mathematical algorithms. To obtain the measurements, this work explored the application of high speed chemiluminescence diagnostics and the use of fiber-based endoscopes (FBEs) for non-intrusive and multi-perspective chemiluminescence imaging up to 20 kHz. Non-intrusive and full-field imaging measurements provide a wealth of information for model validation and design optimization of propulsion systems. However, it is challenging to obtain such measurements due to various implementation difficulties such as optical access, thermal management, and equipment cost. This work therefore explores the application of FBEs for non-intrusive imaging to supersonic propulsion systems. The FBEs used in this work are demonstrated to overcome many of the aforementioned difficulties and provided datasets from multiple angular positions up to 20 kHz in a supersonic combustor. The combustor operated on ethylene fuel at Mach 2 with an inlet stagnation temperature and pressure of approximately 640 degrees Fahrenheit and 70 psia, respectively. The imaging measurements were obtained from eight perspectives simultaneously, providing full-field datasets under such flow conditions for the first time, allowing the possibility of inferring multi-dimensional measurements. Due to the high speed and multi-perspective nature, such new diagnostic capability generates a large volume of data and calls for analysis algorithms that can process the data and extract key physics effectively. To extract the key combustion dynamics from the measurements, three mathematical methods were investigated in this work: Fourier analysis, proper orthogonal decomposition (POD), and wavelet analysis (WA). These algorithms were first demonstrated and tested on imaging measurements obtained from one perspective in a sub-sonic combustor (up to Mach 0.2). The results show that these algorithms are effective in extracting the key physics from large datasets, including the characteristic frequencies of flow-flame interactions especially during transient processes such as lean blow off and ignition. After these relatively simple tests and demonstrations, these algorithms were applied to process the measurements obtained from multi-perspective in the supersonic combustor. compared to past analyses (which have been limited to data obtained from one perspective only), the availability of data at multiple perspective provide further insights into the flame and flow structures in high speed flows. In summary, this work shows that high speed chemiluminescence is a simple yet powerful combustion diagnostic. Especially when combined with FBEs and the analyses algorithms described in this work, such diagnostics provide full-field imaging at high repetition rate in challenging flows. Based on such measurements, a wealth of information can be obtained from proper analysis algorithms, including characteristic frequency, dominating flame modes, and even multi-dimensional flame and flow structures.

Determination of car on-road black carbon and particle number emission factors and comparison between mobile and stationary measurements

NASA Astrophysics Data System (ADS)

Ježek, I.; Drinovec, L.; Ferrero, L.; Carriero, M.; Močnik, G.

2015-01-01

We have used two methods for measuring emission factors (EFs) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured, and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EFs of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars; hence, we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, and we rather describe the vehicle EF with a characteristic value and a super emission tail.

Motivational salience signal in the basal forebrain is coupled with faster and more precise decision speed.

PubMed

Avila, Irene; Lin, Shih-Chieh

2014-03-01

The survival of animals depends critically on prioritizing responses to motivationally salient stimuli. While it is generally believed that motivational salience increases decision speed, the quantitative relationship between motivational salience and decision speed, measured by reaction time (RT), remains unclear. Here we show that the neural correlate of motivational salience in the basal forebrain (BF), defined independently of RT, is coupled with faster and also more precise decision speed. In rats performing a reward-biased simple RT task, motivational salience was encoded by BF bursting response that occurred before RT. We found that faster RTs were tightly coupled with stronger BF motivational salience signals. Furthermore, the fraction of RT variability reflecting the contribution of intrinsic noise in the decision-making process was actively suppressed in faster RT distributions with stronger BF motivational salience signals. Artificially augmenting the BF motivational salience signal via electrical stimulation led to faster and more precise RTs and supports a causal relationship. Together, these results not only describe for the first time, to our knowledge, the quantitative relationship between motivational salience and faster decision speed, they also reveal the quantitative coupling relationship between motivational salience and more precise RT. Our results further establish the existence of an early and previously unrecognized step in the decision-making process that determines both the RT speed and variability of the entire decision-making process and suggest that this novel decision step is dictated largely by the BF motivational salience signal. Finally, our study raises the hypothesis that the dysregulation of decision speed in conditions such as depression, schizophrenia, and cognitive aging may result from the functional impairment of the motivational salience signal encoded by the poorly understood noncholinergic BF neurons.

Motivational Salience Signal in the Basal Forebrain Is Coupled with Faster and More Precise Decision Speed

PubMed Central

Avila, Irene; Lin, Shih-Chieh

2014-01-01

The survival of animals depends critically on prioritizing responses to motivationally salient stimuli. While it is generally believed that motivational salience increases decision speed, the quantitative relationship between motivational salience and decision speed, measured by reaction time (RT), remains unclear. Here we show that the neural correlate of motivational salience in the basal forebrain (BF), defined independently of RT, is coupled with faster and also more precise decision speed. In rats performing a reward-biased simple RT task, motivational salience was encoded by BF bursting response that occurred before RT. We found that faster RTs were tightly coupled with stronger BF motivational salience signals. Furthermore, the fraction of RT variability reflecting the contribution of intrinsic noise in the decision-making process was actively suppressed in faster RT distributions with stronger BF motivational salience signals. Artificially augmenting the BF motivational salience signal via electrical stimulation led to faster and more precise RTs and supports a causal relationship. Together, these results not only describe for the first time, to our knowledge, the quantitative relationship between motivational salience and faster decision speed, they also reveal the quantitative coupling relationship between motivational salience and more precise RT. Our results further establish the existence of an early and previously unrecognized step in the decision-making process that determines both the RT speed and variability of the entire decision-making process and suggest that this novel decision step is dictated largely by the BF motivational salience signal. Finally, our study raises the hypothesis that the dysregulation of decision speed in conditions such as depression, schizophrenia, and cognitive aging may result from the functional impairment of the motivational salience signal encoded by the poorly understood noncholinergic BF neurons. PMID:24642480

Statistical Post-Processing of Wind Speed Forecasts to Estimate Relative Economic Value

NASA Astrophysics Data System (ADS)

Courtney, Jennifer; Lynch, Peter; Sweeney, Conor

2013-04-01

The objective of this research is to get the best possible wind speed forecasts for the wind energy industry by using an optimal combination of well-established forecasting and post-processing methods. We start with the ECMWF 51 member ensemble prediction system (EPS) which is underdispersive and hence uncalibrated. We aim to produce wind speed forecasts that are more accurate and calibrated than the EPS. The 51 members of the EPS are clustered to 8 weighted representative members (RMs), chosen to minimize the within-cluster spread, while maximizing the inter-cluster spread. The forecasts are then downscaled using two limited area models, WRF and COSMO, at two resolutions, 14km and 3km. This process creates four distinguishable ensembles which are used as input to statistical post-processes requiring multi-model forecasts. Two such processes are presented here. The first, Bayesian Model Averaging, has been proven to provide more calibrated and accurate wind speed forecasts than the ECMWF EPS using this multi-model input data. The second, heteroscedastic censored regression is indicating positive results also. We compare the two post-processing methods, applied to a year of hindcast wind speed data around Ireland, using an array of deterministic and probabilistic verification techniques, such as MAE, CRPS, probability transform integrals and verification rank histograms, to show which method provides the most accurate and calibrated forecasts. However, the value of a forecast to an end-user cannot be fully quantified by just the accuracy and calibration measurements mentioned, as the relationship between skill and value is complex. Capturing the full potential of the forecast benefits also requires detailed knowledge of the end-users' weather sensitive decision-making processes and most importantly the economic impact it will have on their income. Finally, we present the continuous relative economic value of both post-processing methods to identify which is more beneficial to the wind energy industry of Ireland.

Field experiments to determine wave propagation principles and mechanical properties of snow

NASA Astrophysics Data System (ADS)

Simioni, Stephan; Gebhard, Felix; Dual, Jürg; Schweizer, Jürg

2017-04-01

To understand the release of snow avalanches by explosions one needs to know how acoustic waves travel above and within the snowpack. Hitherto, wave propagation was investigated in the laboratory with small samples or in the field in the shock wave region. We developed a measurement system and layout to derive wave attenuation in snow, wave speeds and elastic moduli on small-scale (1-2 m) field experiments to close the gap between the lab scale (0.1 m) and the scale of artificial release (10-100 m). We used solid explosives and hammer blows to create the load and accelerometers to measure the resulting wave within the snowpack. The strong attenuation we observed indicates that we measured the second longitudinal wave which propagates through the pore space. The wave speeds, however, corresponded to the speeds of the first longitudinal wave within the ice skeleton. The elastic moduli were high on the order of several tens of MPa for lower densities (150 kg m-3) and agreed well with earlier lab studies, in particular for the higher densities 250-400 kg m-3). However, the scatter was rather large as expected for in-situ experiments in the layered snow cover. In addition, we measured accelerations during propagation saw test experiments. The propagation of cracks during this type of snow instability test has mainly been studied by analysing the bending of the slab (due to the saw cut) using particle tracking velocimetry. We used the accelerometers to measure crack propagation speeds. The wave speeds were slightly higher for most experiments than reported previously. Furthermore, in some experiments, we encountered to different wave types with one propagating at a higher speed. This finding may be interpreted as the actual crack propagation and the settling of the weak layer (collapse wave). Our results show that field measurements of propagation properties are feasible and that crack propagation as observed during propagation saw tests may involve different processes that need to be further investigated.

Cognitive domains that predict time to diagnosis in prodromal Huntington disease.

PubMed

Harrington, Deborah Lynn; Smith, Megan M; Zhang, Ying; Carlozzi, Noelle E; Paulsen, Jane S

2012-06-01

Prodromal Huntington's disease (prHD) is associated with a myriad of cognitive changes but the domains that best predict time to clinical diagnosis have not been studied. This is a notable gap because some domains may be more sensitive to cognitive decline, which would inform clinical trials. The present study sought to characterise cognitive domains underlying a large test battery and for the first time, evaluate their ability to predict time to diagnosis. Participants included gene negative and gene positive prHD participants who were enrolled in the PREDICT-HD study. The CAG-age product (CAP) score was the measure of an individual's genetic signature. A factor analysis of 18 tests was performed to identify sets of measures or latent factors that elucidated core constructs of tests. Factor scores were then fit to a survival model to evaluate their ability to predict time to diagnosis. Six factors were identified: (1) speed/inhibition, (2) verbal working memory, (3) motor planning/speed, (4) attention-information integration, (5) sensory-perceptual processing and (6) verbal learning/memory. Factor scores were sensitive to worsening of cognitive functioning in prHD, typically more so than performances on individual tests comprising the factors. Only the motor planning/speed and sensory-perceptual processing factors predicted time to diagnosis, after controlling for CAP scores and motor symptoms. Conclusions The results suggest that motor planning/speed and sensory-perceptual processing are important markers of disease prognosis. The findings also have implications for using composite indices of cognition in preventive Huntington's disease trials where they may be more sensitive than individual tests.

Fuzzy Logic Enhanced Digital PIV Processing Software

NASA Technical Reports Server (NTRS)

Wernet, Mark P.

1999-01-01

Digital Particle Image Velocimetry (DPIV) is an instantaneous, planar velocity measurement technique that is ideally suited for studying transient flow phenomena in high speed turbomachinery. DPIV is being actively used at the NASA Glenn Research Center to study both stable and unstable operating conditions in a high speed centrifugal compressor. Commercial PIV systems are readily available which provide near real time feedback of the PIV image data quality. These commercial systems are well designed to facilitate the expedient acquisition of PIV image data. However, as with any general purpose system, these commercial PIV systems do not meet all of the data processing needs required for PIV image data reduction in our compressor research program. An in-house PIV PROCessing (PIVPROC) code has been developed for reducing PIV data. The PIVPROC software incorporates fuzzy logic data validation for maximum information recovery from PIV image data. PIVPROC enables combined cross-correlation/particle tracking wherein the highest possible spatial resolution velocity measurements are obtained.

In-line mixing states monitoring of suspensions using ultrasonic reflection technique.

PubMed

Zhan, Xiaobin; Yang, Yili; Liang, Jian; Zou, Dajun; Zhang, Jiaqi; Feng, Luyi; Shi, Tielin; Li, Xiwen

2016-02-01

Based on the measurement of echo signal changes caused by different concentration distributions in the mixing process, a simple ultrasonic reflection technique is proposed for in-line monitoring of the mixing states of suspensions in an agitated tank in this study. The relation between the echo signals and the concentration of suspensions is studied, and the mixing process of suspensions is tracked by in-line measurement of ultrasonic echo signals using two ultrasonic sensors. Through the analysis of echo signals over time, the mixing states of suspensions are obtained, and the homogeneity of suspensions is quantified. With the proposed technique, the effects of impeller diameter and agitation speed on the mixing process are studied, and the optimal agitation speed and the minimum mixing time to achieve the maximum homogeneity are acquired under different operating conditions and design parameters. The proposed technique is stable and feasible and shows great potential for in-line monitoring of mixing states of suspensions. Copyright © 2015 Elsevier B.V. All rights reserved.

Age-related delay in visual and auditory evoked responses is mediated by white- and grey-matter differences.

PubMed

Price, D; Tyler, L K; Neto Henriques, R; Campbell, K L; Williams, N; Treder, M S; Taylor, J R; Henson, R N A

2017-06-09

Slowing is a common feature of ageing, yet a direct relationship between neural slowing and brain atrophy is yet to be established in healthy humans. We combine magnetoencephalographic (MEG) measures of neural processing speed with magnetic resonance imaging (MRI) measures of white and grey matter in a large population-derived cohort to investigate the relationship between age-related structural differences and visual evoked field (VEF) and auditory evoked field (AEF) delay across two different tasks. Here we use a novel technique to show that VEFs exhibit a constant delay, whereas AEFs exhibit delay that accumulates over time. White-matter (WM) microstructure in the optic radiation partially mediates visual delay, suggesting increased transmission time, whereas grey matter (GM) in auditory cortex partially mediates auditory delay, suggesting less efficient local processing. Our results demonstrate that age has dissociable effects on neural processing speed, and that these effects relate to different types of brain atrophy.

Age-related delay in visual and auditory evoked responses is mediated by white- and grey-matter differences

PubMed Central

Price, D.; Tyler, L. K.; Neto Henriques, R.; Campbell, K. L.; Williams, N.; Treder, M.S.; Taylor, J. R.; Brayne, Carol; Bullmore, Edward T.; Calder, Andrew C.; Cusack, Rhodri; Dalgleish, Tim; Duncan, John; Matthews, Fiona E.; Marslen-Wilson, William D.; Rowe, James B.; Shafto, Meredith A.; Cheung, Teresa; Davis, Simon; Geerligs, Linda; Kievit, Rogier; McCarrey, Anna; Mustafa, Abdur; Samu, David; Tsvetanov, Kamen A.; van Belle, Janna; Bates, Lauren; Emery, Tina; Erzinglioglu, Sharon; Gadie, Andrew; Gerbase, Sofia; Georgieva, Stanimira; Hanley, Claire; Parkin, Beth; Troy, David; Auer, Tibor; Correia, Marta; Gao, Lu; Green, Emma; Allen, Jodie; Amery, Gillian; Amunts, Liana; Barcroft, Anne; Castle, Amanda; Dias, Cheryl; Dowrick, Jonathan; Fair, Melissa; Fisher, Hayley; Goulding, Anna; Grewal, Adarsh; Hale, Geoff; Hilton, Andrew; Johnson, Frances; Johnston, Patricia; Kavanagh-Williamson, Thea; Kwasniewska, Magdalena; McMinn, Alison; Norman, Kim; Penrose, Jessica; Roby, Fiona; Rowland, Diane; Sargeant, John; Squire, Maggie; Stevens, Beth; Stoddart, Aldabra; Stone, Cheryl; Thompson, Tracy; Yazlik, Ozlem; Barnes, Dan; Dixon, Marie; Hillman, Jaya; Mitchell, Joanne; Villis, Laura; Henson, R. N. A.

2017-01-01

Slowing is a common feature of ageing, yet a direct relationship between neural slowing and brain atrophy is yet to be established in healthy humans. We combine magnetoencephalographic (MEG) measures of neural processing speed with magnetic resonance imaging (MRI) measures of white and grey matter in a large population-derived cohort to investigate the relationship between age-related structural differences and visual evoked field (VEF) and auditory evoked field (AEF) delay across two different tasks. Here we use a novel technique to show that VEFs exhibit a constant delay, whereas AEFs exhibit delay that accumulates over time. White-matter (WM) microstructure in the optic radiation partially mediates visual delay, suggesting increased transmission time, whereas grey matter (GM) in auditory cortex partially mediates auditory delay, suggesting less efficient local processing. Our results demonstrate that age has dissociable effects on neural processing speed, and that these effects relate to different types of brain atrophy. PMID:28598417

Control system for several rotating mirror camera synchronization operation

NASA Astrophysics Data System (ADS)

Liu, Ningwen; Wu, Yunfeng; Tan, Xianxiang; Lai, Guoji

1997-05-01

This paper introduces a single chip microcomputer control system for synchronization operation of several rotating mirror high-speed cameras. The system consists of four parts: the microcomputer control unit (including the synchronization part and precise measurement part and the time delay part), the shutter control unit, the motor driving unit and the high voltage pulse generator unit. The control system has been used to control the synchronization working process of the GSI cameras (driven by a motor) and FJZ-250 rotating mirror cameras (driven by a gas driven turbine). We have obtained the films of the same objective from different directions in different speed or in same speed.

The Effect of One Night's Sleep Deprivation on Adolescent Neurobehavioral Performance

PubMed Central

Louca, Mia; Short, Michelle A.

2014-01-01

Study Objectives: To investigate the effects of one night's sleep deprivation on neurobehavioral functioning in adolescents. Design: Participants completed a neurobehavioral test battery measuring sustained attention, reaction speed, cognitive processing speed, sleepiness, and fatigue every 2 h during wakefulness. Baseline performance (defined as those test bouts between 09:00 and 19:00 on days 2 and 3, following two 10-h sleep opportunities) were compared to performance at the same clock time the day following total sleep deprivation. Setting: The sleep laboratory at the Centre for Sleep Research. Participants: Twelve healthy adolescents (6 male), aged 14-18 years (mean = 16.17, standard deviation = 0.83). Measurements and Results: Sustained attention, reaction speed, cognitive processing speed, and subjective sleepiness were all significantly worse following one night without sleep than following 10-h sleep opportunities (all main effects of day, P < 0.05). Sleep deprivation led to increased variability on objective performance measures. There were between-subjects differences in response to sleep loss that were task-specific, suggesting that adolescents may not only vary in terms of the degree to which they are affected by sleep loss but also the domains in which they are affected. Conclusions: These findings suggest that one night of total sleep deprivation has significant deleterious effects upon neurobehavioral performance and subjective sleepiness. These factors impair daytime functioning in adolescents, leaving them at greater risk of poor academic and social functioning and accidents and injuries. Citation: Louca M, Short MA. The effect of one night's sleep deprivation on adolescent neurobehavioral performance. SLEEP 2014;37(11):1799-1807. PMID:25364075

A dynamic processes study of PM retention by trees under different wind conditions.

PubMed

Xie, Changkun; Kan, Liyan; Guo, Jiankang; Jin, Sijia; Li, Zhigang; Chen, Dan; Li, Xin; Che, Shengquan

2018-02-01

Particulate matter (PM) is one of the most serious environmental problems, exacerbating respiratory and vascular illnesses. Plants have the ability to reduce non-point source PM pollution through retention on leaves and branches. Studies of the dynamic processes of PM retention by plants and the mechanisms influencing this process will help to improve the efficiency of urban greening for PM reduction. We examined dynamic processes of PM retention and the major factors influencing PM retention by six trees with different branch structure characteristics in wind tunnel experiments at three different wind speeds. The results showed that the changes of PM numbers retained by plant leaves over time were complex dynamic processes for which maximum values could exceed minimum values by over 10 times. The average value of PM measured in multiple periods and situations can be considered a reliable indicator of the ability of the plant to retain PM. The dynamic processes were similar for PM 10 and PM 2.5 . They could be clustered into three groups simulated by continually-rising, inverse U-shaped, and U-shaped polynomial functions, respectively. The processes were the synthetic effect of characteristics such as species, wind speed, period of exposure and their interactions. Continually-rising functions always explained PM retention in species with extremely complex branch structure. Inverse U-shaped processes explained PM retention in species with relatively simple branch structure and gentle wind. The U-shaped processes mainly explained PM retention at high wind speeds and in species with a relatively simple crown. These results indicate that using plants with complex crowns in urban greening and decreasing wind speed in plant communities increases the chance of continually-rising or inverse U-shaped relationships, which have a positive effect in reducing PM pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measuring impact rebound with photography.

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

Sumali, Hartono

2010-05-01

To study the rebound of a sphere colliding against a flat wall, a test setup was developed where the sphere is suspended with strings as a pendulum, elevated, and gravity-released to impact the wall. The motion of the sphere was recorded with a highspeed camera and traced with an image-processing program. From the speed of the sphere before and after each collision, the coefficient of restitution was computed, and shown to be a function of impact speed as predicted analytically.

High-speed precise cell patterning by pulsed electrohydrodynamic jet printing

NASA Astrophysics Data System (ADS)

Makaev, A. V.; Mingaliev, E. A.; Karpov, V. R.; Zubarev, I. V.; Shur, V. Ya; El'kina, O. S.

2017-10-01

The generation of micro-droplets of nutrient medium with living cells by pulsed electrohydrodynamic printing has been studied. In-situ visualization by high-speed camera made it possible to measure the characteristic times of droplet generation process and to determine the optimal printing parameters. Maximal frequency of stable generation was achieved at 700 Hz. This technique was applied successfully for drop-on-demand printing of culture medium with live HeLa cells and yeasts.

DURIP: An Ultrafast Testbed for Comprehensive Characterization of Photonics, Electronic, and Optoelectronic Properties of Inegrated Nanophotonic Structures

DTIC Science & Technology

2017-10-14

Department of the Army position, policy or decision , unless so designated by other documentation. 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS (ES...characterization equipment to an al- ready available photonic characterization setup. The following table details of the spent budget and the list of purchased ...measure the response of a high-speed optical signal processing platform. The same architecture also can be used to charac- terize high-speed

Nugget Structure Evolution with Rotation Speed for High-Rotation-Speed Friction-Stir-Welded 6061 Aluminum Alloy

NASA Astrophysics Data System (ADS)

Zhang, H. J.; Wang, M.; Zhu, Z.; Zhang, X.; Yu, T.; Wu, Z. Q.

2018-03-01

High-rotation-speed friction stir welding (HRS-FSW) is a promising technique to reduce the welding loads during FSW and thus facilitates the application of FSW for in situ fabrication and repair. In this study, 6061 aluminum alloy was friction stir welded at high-rotation speeds ranging from 3000 to 7000 rpm at a fixed welding speed of 50 mm/min, and the effects of rotation speed on the nugget zone macro- and microstructures were investigated in detail in order to illuminate the process features. Temperature measurements during HRS-FSW indicated that the peak temperature did not increase consistently with rotation speed; instead, it dropped remarkably at 5000 rpm because of the lowering of material shear stress. The nugget size first increased with rotation speed until 5000 rpm and then decreased due to the change of the dominant tool/workpiece contact condition from sticking to sliding. At the rotation speed of 5000 rpm, where the weld material experienced weaker thermal effect and higher-strain-rate plastic deformation, the nugget exhibited relatively small grain size, large textural intensity, and high dislocation density. Consequently, the joint showed superior nugget hardness and simultaneously a slightly low tensile ductility.

Development of an imaging system for single droplet characterization using a droplet generator.

PubMed

Minov, S Vulgarakis; Cointault, F; Vangeyte, J; Pieters, J G; Hijazi, B; Nuyttens, D

2012-01-01

The spray droplets generated by agricultural nozzles play an important role in the application accuracy and efficiency of plant protection products. The limitations of the non-imaging techniques and the recent improvements in digital image acquisition and processing increased the interest in using high speed imaging techniques in pesticide spray characterisation. The goal of this study was to develop an imaging technique to evaluate the characteristics of a single spray droplet using a piezoelectric single droplet generator and a high speed imaging technique. Tests were done with different camera settings, lenses, diffusers and light sources. The experiments have shown the necessity for having a good image acquisition and processing system. Image analysis results contributed in selecting the optimal set-up for measuring droplet size and velocity which consisted of a high speed camera with a 6 micros exposure time, a microscope lens at a working distance of 43 cm resulting in a field of view of 1.0 cm x 0.8 cm and a Xenon light source without diffuser used as a backlight. For measuring macro-spray characteristics as the droplet trajectory, the spray angle and the spray shape, a Macro Video Zoom lens at a working distance of 14.3 cm with a bigger field of view of 7.5 cm x 9.5 cm in combination with a halogen spotlight with a diffuser and the high speed camera can be used.

The effect of one night's sleep deprivation on adolescent neurobehavioral performance.

PubMed

Louca, Mia; Short, Michelle A

2014-11-01

To investigate the effects of one night's sleep deprivation on neurobehavioral functioning in adolescents. Participants completed a neurobehavioral test battery measuring sustained attention, reaction speed, cognitive processing speed, sleepiness, and fatigue every 2 h during wakefulness. Baseline performance (defined as those test bouts between 09:00 and 19:00 on days 2 and 3, following two 10-h sleep opportunities) were compared to performance at the same clock time the day following total sleep deprivation. The sleep laboratory at the Centre for Sleep Research. Twelve healthy adolescents (6 male), aged 14-18 years (mean = 16.17, standard deviation = 0.83). Sustained attention, reaction speed, cognitive processing speed, and subjective sleepiness were all significantly worse following one night without sleep than following 10-h sleep opportunities (all main effects of day, P < 0.05). Sleep deprivation led to increased variability on objective performance measures. There were between-subjects differences in response to sleep loss that were task-specific, suggesting that adolescents may not only vary in terms of the degree to which they are affected by sleep loss but also the domains in which they are affected. These findings suggest that one night of total sleep deprivation has significant deleterious effects upon neurobehavioral performance and subjective sleepiness. These factors impair daytime functioning in adolescents, leaving them at greater risk of poor academic and social functioning and accidents and injuries.

Processing Speed and Executive Functions in Cognitive Aging: How to Disentangle Their Mutual Relationship?

ERIC Educational Resources Information Center

Albinet, Cedric T.; Boucard, Geoffroy; Bouquet, Cedric; Audiffren, Michel

2012-01-01

The processing-speedtheory and the prefrontal-executivetheory are competing theories of cognitive aging. Here we used a theoretically and methodologically-driven framework to investigate the relationships among measures classically used to assess these two theoretical constructs. Twenty-eight young adults (18-32 years) and 39 healthy older adults…

Real-time tracking using stereo and motion: Visual perception for space robotics

NASA Technical Reports Server (NTRS)

Nishihara, H. Keith; Thomas, Hans; Huber, Eric; Reid, C. Ann

1994-01-01

The state-of-the-art in computing technology is rapidly attaining the performance necessary to implement many early vision algorithms at real-time rates. This new capability is helping to accelerate progress in vision research by improving our ability to evaluate the performance of algorithms in dynamic environments. In particular, we are becoming much more aware of the relative stability of various visual measurements in the presence of camera motion and system noise. This new processing speed is also allowing us to raise our sights toward accomplishing much higher-level processing tasks, such as figure-ground separation and active object tracking, in real-time. This paper describes a methodology for using early visual measurements to accomplish higher-level tasks; it then presents an overview of the high-speed accelerators developed at Teleos to support early visual measurements. The final section describes the successful deployment of a real-time vision system to provide visual perception for the Extravehicular Activity Helper/Retriever robotic system in tests aboard NASA's KC135 reduced gravity aircraft.

EFFECTS OF NON-CIRCULAR MOTIONS ON AZIMUTHAL COLOR GRADIENTS

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

Martinez-Garcia, Eric E.; Gonzalez-Lopezlira, Rosa A.; Gomez, Gilberto C., E-mail: emartinez@cida.v, E-mail: r.gonzalez@crya.unam.m, E-mail: g.gomez@crya.unam.m

2009-12-20

Assuming that density waves trigger star formation, and that young stars preserve the velocity components of the molecular gas where they are born, we analyze the effects that non-circular gas orbits have on color gradients across spiral arms. We try two approaches, one involving semianalytical solutions for spiral shocks, and another with magnetohydrodynamic (MHD) numerical simulation data. We find that, if non-circular motions are ignored, the comparison between observed color gradients and stellar population synthesis models would in principle yield pattern speed values that are systematically too high for regions inside corotation, with the difference between the real and themore » measured pattern speeds increasing with decreasing radius. On the other hand, image processing and pixel averaging result in systematically lower measured spiral pattern speed values, regardless of the kinematics of stellar orbits. The net effect is that roughly the correct pattern speeds are recovered, although the trend of higher measured OMEGA{sub p} at lower radii (as expected when non-circular motions exist but are neglected) should still be observed. We examine the MartInez-GarcIa et al. photometric data and confirm that this is indeed the case. The comparison of the size of the systematic pattern speed offset in the data with the predictions of the semianalytical and MHD models corroborates that spirals are more likely to end at outer Lindblad resonance, as these authors had already found.« less

Assessment of JVX Proprotor Performance Data in Hover and Airplane-Mode Flight Conditions

NASA Technical Reports Server (NTRS)

Acree, C. W., Jr.

2016-01-01

A 0.656-scale V-22 proprotor, the Joint Vertical Experimental (JVX) rotor, was tested at the NASA Ames Research Center in both hover and airplane-mode (high-speed axial flow) flight conditions, up to an advance ratio of 0.562 (231 knots). This paper examines the two principal data sets generated by those tests, and includes investigations of hub spinner tares, torque/thrust measurement interactions, tunnel blockage effects, and other phenomena suspected of causing erroneous measurements or predictions. Uncertainties in hover and high-speed data are characterized. The results are reported here to provide guidance for future wind tunnel tests, data processing, and data analysis.

Potassium channel gene associations with joint processing speed and white matter impairments in schizophrenia.

PubMed

Bruce, H A; Kochunov, P; Paciga, S A; Hyde, C L; Chen, X; Xie, Z; Zhang, B; Xi, H S; O'Donnell, P; Whelan, C; Schubert, C R; Bellon, A; Ament, S A; Shukla, D K; Du, X; Rowland, L M; O'Neill, H; Hong, L E

2017-06-01

Patients with schizophrenia show decreased processing speed on neuropsychological testing and decreased white matter integrity as measured by diffusion tensor imaging, two traits shown to be both heritable and genetically associated indicating that there may be genes that influence both traits as well as schizophrenia disease risk. The potassium channel gene family is a reasonable candidate to harbor such a gene given the prominent role potassium channels play in the central nervous system in signal transduction, particularly in myelinated axons. We genotyped members of the large potassium channel gene family focusing on putatively functional single nucleotide polymorphisms (SNPs) in a population of 363 controls, 194 patients with schizophrenia spectrum disorder (SSD) and 28 patients with affective disorders with psychotic features who completed imaging and neuropsychological testing. We then performed three association analyses using three phenotypes - processing speed, whole-brain white matter fractional anisotropy (FA) and schizophrenia spectrum diagnosis. We extracted SNPs showing an association at a nominal P value of <0.05 with all three phenotypes in the expected direction: decreased processing speed, decreased FA and increased risk of SSD. A single SNP, rs8234, in the 3' untranslated region of voltage-gated potassium channel subfamily Q member 1 (KCNQ1) was identified. Rs8234 has been shown to affect KCNQ1 expression levels, and KCNQ1 levels have been shown to affect neuronal action potentials. This exploratory analysis provides preliminary data suggesting that KCNQ1 may contribute to the shared risk for diminished processing speed, diminished white mater integrity and increased risk of schizophrenia. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Cognitive inconsistency in bipolar patients is determined by increased intra-individual variability in initial phase of task performance.

PubMed

Krukow, Paweł; Szaniawska, Ola; Harciarek, Michał; Plechawska-Wójcik, Małgorzata; Jonak, Kamil

2017-03-01

Bipolar patients show high intra-individual variability during cognitive processing. However, it is not known whether there are a specific fluctuations of variability contributing to the overall high cognitive inconsistency. The objective was to compare dynamic profiles of patients and healthy controls to identify hypothetical differences and their associations with overall variability and processing speed. Changes of reaction times iSD during processing speed test performance over time was measured by dividing the iSD for whole task into four consecutive parts. Motor speed and cognitive effort were controlled. Patients with BD exhibited significantly lower results regarding processing speed and higher intra-individual variability comparing with HC. The profile of intra-individual variability changes over time of performance was significantly different in BD versus HC groups: F(3, 207)=8.60, p<0.0001, η p 2 =0.11. iSD of BD patients in the initial phase of performance was three times higher than in the last. There was no significant differences between four intervals in HC group. Inter-group difference in the initial part of the profiles was significant also after controlling for several cognitive and clinical variables. Applied computer version of Cognitive Speed Test was relatively new and, thus, replication studies are needed. Effect seen in the present study is driven mainly by the BD type I. Patients with BD exhibits problems with setting a stimulus-response association in starting phase of cognitive processing. This deficit may negatively interfere with the other cognitive functions, decreasing level of psychosocial functioning, therefore should be explored in future studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of deformation path on microstructure, microhardness and texture evolution of interstitial free steel fabricated by differential speed rolling

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

Hamad, Kotiba; Chung, Bong Kwon; Ko, Young Gun, E-mail: younggun@ynu.ac.kr

2014-08-15

This paper reports the effect of the deformation path on the microstructure, microhardness, and texture evolution of interstitial free (IF) steel processed by differential speed rolling (DSR) method. For this purpose, total height reductions of 50% and 75% were imposed on the samples by a series of differential speed rolling operations with various height reductions per pass (deformation levels) ranging from 10 to 50% under a fixed roll speed ratio of 1:4 for the upper and lower rolls, respectively. Microstructural observations using transmission electron microscopy and electron backscattered diffraction measurements showed that the samples rolled at deformation level of 50%more » had the finest mean grain size (∼ 0.5 μm) compared to the other counterparts; also the samples rolled at deformation level of 50% showed a more uniform microstructure. Based on the microhardness measurements along the thickness direction of the deformed samples, gradual evolution of the microhardness value and its homogeneity was observed with the increase of the deformation level per pass. Texture analysis showed that, as the deformation level per pass increased, the fraction of alpha fiber and gamma fiber in the deformed samples increased. The textures obtained by the differential speed rolling process under the lubricated condition would be equivalent to those obtained by the conventional rolling. - Highlights: • Effect of DSR deformation path on microstructure of IF steel is significant. • IF steel rolled at deformation level of 50% has the ultrafine grains of ∼ 0.5 μm. • Rolling texture components are pronounced with increasing deformation level.« less

Individual differences in executive processing predict susceptibility to interference in verbal working memory.

PubMed

Hedden, Trey; Yoon, Carolyn

2006-09-01

Recent theories have suggested that resistance to interference is a unifying principle of executive function and that individual differences in interference may be explained by executive function (M. J. Kane & R. W. Engle, 2002). Measures of executive function, memory, and perceptual speed were obtained from 121 older adults (ages 63-82). We used structural equation modeling to investigate the relationships of these constructs with interference in a working memory task. Executive function was best described as two related subcomponent processes: shifting and updating goal-relevant representations and inhibition of proactive interference. These subcomponents were distinct from verbal and visual memory and speed. Individual differences in interference susceptibility and recollection were best predicted by shifting and updating and by resistance to proactive interference, and variability in familiarity was predicted by resistance to proactive interference and speed. ((c) 2006 APA, all rights reserved).

Mathematical modeling of fluid flow in aluminum ladles for degasification with impeller - injector

NASA Astrophysics Data System (ADS)

Ramos-Gómez, E.; González-Rivera, C.; Ramírez-Argáez, M. A.

2012-09-01

In this work a fundamental Eulerian mathematical model was developed to simulate fluid flow in a water physical model of an aluminum ladle equipped with impeller for degassing treatment. The effect of critical process parameters such as rotor speed, gas flow rate on the fluid flow and vortex formation was analyzed with this model. Commercial CFD code PHOENICS 3.4 was used to solve all conservation equations governing the process for this twophase fluid flow system. The mathematical model was successfully validated against experimentally measured liquid velocity and turbulent profiles in a physical model. From the results it was concluded that the angular speed of the impeller is the most important parameter promoting better stirred baths. Pumping effect of the impeller is increased as impeller rotation speed increases. Gas flow rate is detrimental on bath stirring and diminishes pumping effect of impeller.

Interpretation of plasma impurity deposition probes. Analytic approximation

NASA Astrophysics Data System (ADS)

Stangeby, P. C.

1987-10-01

Insertion of a probe into the plasma induces a high speed flow of the hydrogenic plasma to the probe which, by friction, accelerates the impurity ions to velocities approaching the hydrogenic ion acoustic speed, i.e., higher than the impurity ion thermal speed. A simple analytic theory based on this effect provides a relation between impurity fluxes to the probe Γimp and the undisturbed impurity ion density nimp, with the hydrogenic temperature and density as input parameters. Probe size also influences the collection process and large probes are found to attract a higher flux density than small probes in the same plasma. The quantity actually measured, cimp, the impurity atom surface density (m-2) net-deposited on the probe, is related to Γimp and thus to nimp by taking into account the partial removal of deposited material caused by sputtering and the redeposition process.

High resolution imaging of a subsonic projectile using automated mirrors with large aperture

NASA Astrophysics Data System (ADS)

Tateno, Y.; Ishii, M.; Oku, H.

2017-02-01

Visual tracking of high-speed projectiles is required for studying the aerodynamics around the objects. One solution to this problem is a tracking method based on the so-called 1 ms Auto Pan-Tilt (1ms-APT) system that we proposed in previous work, which consists of rotational mirrors and a high-speed image processing system. However, the images obtained with that system did not have high enough resolution to realize detailed measurement of the projectiles because of the size of the mirrors. In this study, we propose a new system consisting of enlarged mirrors for tracking a high-speed projectiles so as to achieve higher-resolution imaging, and we confirmed the effectiveness of the system via an experiment in which a projectile flying at subsonic speed tracked.

Low-Altitude Reconnection Inflow-Outflow Observations During a 2010 November 3 Solar Eruption

NASA Technical Reports Server (NTRS)

Savage, Sabrina L.a; Holman, Gordon; Reeves, Katharine K.; Seaton, Daniel B.; McKenzie, David E.; Su, Yang

2012-01-01

For a solar flare occurring on 2010 November 3, we present observations us- ing several SDO/AIA extreme-ultraviolet (EUV) passbands of an erupting flux rope followed by inflows sweeping into a current sheet region. The inflows are soon followed by outflows appearing to originate from near the termination point of the inflowing motion an observation in line with standard magnetic reconnection models. We measure average inflow plane-of-sky speeds to range from approximately 150 - 690 km s-1 with the initial, high-temperature inflows being the fastest. Using the inflow speeds and a range of Alfven speeds, we estimate the Alfvenic Mach number which appears to decrease with time. We also provide inflow and outflow times with respect to RHESSI count rates and find that the fast, high- temperature inflows occur simultaneously with a peak in the RHESSI thermal light curve. Five candidate inflow-outflow pairs are identified with no more than a minute delay between detections. The inflow speeds of these pairs are measured to be approximately 10(exp 2) km s-1 with outflow speeds ranging from approximately 10(exp 2) - 10(exp 33 km s-1 indicating acceleration during the reconnection process. The fastest of these outflows are in the form of apparently traveling density enhancements along the legs of the loops rather than the loop apexes themselves. These flows could possibly either be accelerated plasma, shocks, or waves prompted by reconnection. The measurements presented here show an order of magnitude difference between the retraction speeds of the loops and the speed of the density enhancements within the loops presumably exiting the reconnection site.

LOW-ALTITUDE RECONNECTION INFLOW-OUTFLOW OBSERVATIONS DURING A 2010 NOVEMBER 3 SOLAR ERUPTION

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

Savage, Sabrina L.; Holman, Gordon; Su, Yang

For a solar flare occurring on 2010 November 3, we present observations using several SDO/AIA extreme-ultraviolet (EUV) passbands of an erupting flux rope followed by inflows sweeping into a current sheet region. The inflows are soon followed by outflows appearing to originate from near the termination point of the inflowing motion-an observation in line with standard magnetic reconnection models. We measure average inflow plane-of-sky speeds to range from {approx}150 to 690 km s{sup -1} with the initial, high-temperature inflows being the fastest. Using the inflow speeds and a range of Alfven speeds, we estimate the Alfvenic Mach number which appearsmore » to decrease with time. We also provide inflow and outflow times with respect to RHESSI count rates and find that the fast, high-temperature inflows occur simultaneously with a peak in the RHESSI thermal light curve. Five candidate inflow-outflow pairs are identified with no more than a minute delay between detections. The inflow speeds of these pairs are measured to be {approx}10{sup 2} km s{sup -1} with outflow speeds ranging from {approx}10{sup 2} to 10{sup 3} km s{sup -1}-indicating acceleration during the reconnection process. The fastest of these outflows are in the form of apparently traveling density enhancements along the legs of the loops rather than the loop apexes themselves. These flows could possibly either be accelerated plasma, shocks, or waves prompted by reconnection. The measurements presented here show an order of magnitude difference between the retraction speeds of the loops and the speed of the density enhancements within the loops-presumably exiting the reconnection site.« less

Thermographic Measurements of the Commercial Laser Powder Bed Fusion Process at NIST

PubMed Central

Lane, Brandon; Moylan, Shawn; Whitenton, Eric; Ma, Li

2016-01-01

Measurement of the high-temperature melt pool region in the laser powder bed fusion (L-PBF) process is a primary focus of researchers to further understand the dynamic physics of the heating, melting, adhesion, and cooling which define this commercially popular additive manufacturing process. This paper will detail the design, execution, and results of high speed, high magnification in-situ thermographic measurements conducted at the National Institute of Standards and Technology (NIST) focusing on the melt pool region of a commercial L-PBF process. Multiple phenomena are observed including plasma plume and hot particle ejection from the melt region. The thermographic measurement process will be detailed with emphasis on the ‘measurability’ of observed phenomena and the sources of measurement uncertainty. Further discussion will relate these thermographic results to other efforts at NIST towards L-PBF process finite element simulation and development of in-situ sensing and control methodologies. PMID:28058036

Measuring Thermal Conductivity of a Small Insulation Sample

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Kuczmarski, Maria A.

2009-01-01

A multiple-throat venturi system has been invented for measuring laminar flow of air or other gas at low speed (1 to 30 cm/s) in a duct while preserving the laminar nature of the flow and keeping the velocity profile across the duct as nearly flat as possible. While means for measuring flows at higher speeds are well established, heretofore, there have been no reliable means for making consistent, accurate measurements in this speed range. In the original application for which this system was invented, the duct leads into the test section of a low-speed wind tunnel wherein uniform, low-speed, laminar flow is required for scientific experiments. The system could also be used to monitor a slow flow of gas in an industrial process like chemical vapor deposition. In the original application, the multiple- throat venturi system is mounted at the inlet end of the duct having a rectangular cross section of 19 by 14 cm, just upstream of an assembly of inlet screens and flow straighteners that help to suppress undesired flow fluctuations (see Figure 1). The basic venturi measurement principle is well established: One measures the difference in pressure between (1) a point just outside the inlet, where the pressure is highest and the kinetic energy lowest; and (2) the narrowest part (the throat) of the venturi passage, where the kinetic energy is highest and the pressure is lowest. Then by use of Bernoulli s equation for the relationship between pressure and kinetic energy, the volumetric flow speed in the duct can be calculated from the pressure difference and the inlet and throat widths. The design of this system represents a compromise among length, pressure recovery, uniformity of flow, and complexity of assembly. Traditionally, venturis are used to measure faster flows in narrower cross sections, with longer upstream and downstream passages to maintain accuracy. The dimensions of the passages of the present venturi system are sized to provide a readily measurable pressure drop. Multiple throats are used to minimize the length needed to recover internal energy and enable the velocity profile to recover to near flatness.

Effects of Prenatal Tobacco, Alcohol and Marijuana Exposure on Processing Speed, Visual-Motor Coordination, and Interhemispheric Transfer

PubMed Central

Willford, Jennifer A.; Chandler, Lynette S.; Goldschmidt, Lidush; Day, Nancy L.

2010-01-01

Deficits in motor control are often reported in children with prenatal alcohol exposure (PAE). Less is known about the effects of prenatal tobacco exposure (PTE) and prenatal marijuana exposure (PME) on motor coordination, and previous studies have not considered whether PTE, PAE, and PME interact to affect motor control. This study investigated the effects of PTE, PAE, and PME as well as current drug use on speed of processing, visual-motor coordination, and interhemispheric transfer in 16-year-old adolescents. Data were collected as part of the Maternal Health Practices and Child Development Project. Adolescents (age 16, n=320) participating in a longitudinal study of the effects of prenatal substance exposure on developmental outcomes were evaluated in this study. The computerized Bimanual Coordination Test (BCT) was used to assess each domain of function. Other important variables, such as demographics, home environment, and psychological characteristics of the mother and adolescent were also considered in the analyses. There were significant and independent effects of PTE, PAE, and PME on processing speed and interhemispheric transfer of information. PTEand PME were associated with deficits in visual motor coordination. There were no interactions between PAE, PTE, and PME. Current tobacco use predicted deficits in speed of processing. Current alcohol and marijuana use by the offspring were not associated with any measures of performance on the BCT. PMID:20600845

Research on signal processing method for total organic carbon of water quality online monitor

NASA Astrophysics Data System (ADS)

Ma, R.; Xie, Z. X.; Chu, D. Z.; Zhang, S. W.; Cao, X.; Wu, N.

2017-08-01

At present, there is no rapid, stable and effective approach of total organic carbon (TOC) measurement in the Marine environmental online monitoring field. Therefore, this paper proposes an online TOC monitor of chemiluminescence signal processing method. The weak optical signal detected by photomultiplier tube can be enhanced and converted by a series of signal processing module: phase-locked amplifier module, fourth-order band pass filter module and AD conversion module. After a long time of comparison test & measurement, compared with the traditional method, on the premise of sufficient accuracy, this chemiluminescence signal processing method can offer greatly improved measuring speed and high practicability for online monitoring.

Emotional Intelligence and cognitive abilities - associations and sex differences.

PubMed

Pardeller, Silvia; Frajo-Apor, Beatrice; Kemmler, Georg; Hofer, Alex

2017-09-01

In order to expand on previous research, this cross-sectional study investigated the relationship between Emotional Intelligence (EI) and cognitive abilities in healthy adults with a special focus on potential sex differences. EI was assessed by means of the Mayer-Salovey-Caruso-Emotional-Intelligence Test (MSCEIT), whereas cognitive abilities were investigated using the Brief Assessment of Cognition in Schizophrenia (BACS), which measures key aspects of cognitive functioning, i.e. verbal memory, working memory, motor speed, verbal fluency, attention and processing speed, and reasoning and problem solving. 137 subjects (65% female) with a mean age of 38.7 ± 11.8 years were included into the study. While males and females were comparable with regard to EI, men achieved significantly higher BACS composite scores and outperformed women in the BACS subscales motor speed, attention and processing speed, and reasoning and problem solving. Verbal fluency significantly predicted EI, whereas the MSCEIT subscale understanding emotions significantly predicted the BACS composite score. Our findings support previous research and emphasize the relevance of considering cognitive abilities when assessing ability EI in healthy individuals.

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.

High-speed measurements of steel-plate deformations during laser surface processing.

PubMed

Jezersek, Matija; Gruden, Valter; Mozina, Janez

2004-10-04

In this paper we present a novel approach to monitoring the deformations of a steel plate's surface during various types of laser processing, e.g., engraving, marking, cutting, bending, and welding. The measuring system is based on a laser triangulation principle, where the laser projector generates multiple lines simultaneously. This enables us to measure the shape of the surface with a high sampling rate (80 Hz with our camera) and high accuracy (+/-7 microm). The measurements of steel-plate deformations for plates of different thickness and with different illumination patterns are presented graphically and in an animation.

Effects of alcoholism severity and smoking on executive neurocognitive function.

PubMed

Glass, Jennifer M; Buu, Anne; Adams, Kenneth M; Nigg, Joel T; Puttler, Leon I; Jester, Jennifer M; Zucker, Robert A

2009-01-01

Neurocognitive deficits in chronic alcoholic men are well documented. Impairments include memory, visual-spatial processing, problem solving and executive function. The cause of impairment could include direct effects of alcohol toxicity, pre-existing cognitive deficits that predispose towards substance abuse, comorbid psychiatric disorders and abuse of substances other than alcohol. Cigarette smoking occurs at higher rates in alcoholism and has been linked to poor cognitive performance, yet the effects of smoking on cognitive function in alcoholism are often ignored. We examined whether chronic alcoholism and chronic smoking have effects on executive function. Alcoholism and smoking were examined in a community-recruited sample of alcoholic and non-alcoholic men (n = 240) using standard neuropsychological and reaction-time measures of executive function. Alcoholism was measured as the average level of alcoholism diagnoses across the study duration (12 years). Smoking was measured in pack-years. Both alcoholism and smoking were correlated negatively with a composite executive function score. For component measures, alcoholism was correlated negatively with a broad range of measures, whereas smoking was correlated negatively with measures that emphasize response speed. In regression analyses, both smoking and alcoholism were significant predictors of executive function composite. However, when IQ is included in the regression analyses, alcoholism severity is no longer significant. Both smoking and alcoholism were related to executive function. However, the effect of alcoholism was not independent of IQ, suggesting a generalized effect, perhaps affecting a wide range of cognitive abilities of which executive function is a component. On the other hand, the effect of smoking on measures relying on response speed were independent of IQ, suggesting a more specific processing speed deficit associated with chronic smoking.

Gender Differences in Processing Speed: A Review of Recent Research

ERIC Educational Resources Information Center

Roivainen, Eka

2011-01-01

A review of recent large-scale studies on gender differences in processing speed and on the cognitive factors assumed to affect processing speed was performed. It was found that females have an advantage in processing speed tasks involving digits and alphabets as well as in rapid naming tasks while males are faster on reaction time tests and…

Evaluation of measurements of propulsion used to reflect changes in walking speed in individuals poststroke.

PubMed

Hsiao, HaoYuan; Zabielski, Thomas M; Palmer, Jacqueline A; Higginson, Jill S; Binder-Macleod, Stuart A

2016-12-08

Recent rehabilitation approaches for individuals poststroke have focused on improving walking speed because it is a reliable measurement that is associated with quality of life. Previous studies have demonstrated that propulsion, the force used to propel the body forward, determines walking speed. However, there are several different ways of measuring propulsion and no studies have identified which measurement best reflects differences in walking speed. The primary purposes of this study were to determine for individuals poststroke, which measurement of propulsion (1) is most closely related to their self-selected walking speeds and (2) best reflects changes in walking speed within a session. Participants (N=43) with chronic poststroke hemiparesis walked at their self-selected and maximal walking speeds on a treadmill. Propulsive impulse, peak propulsive force, and mean propulsive value (propulsive impulse divided by duration) were analyzed. In addition, each participant׳s cadence was calculated. Pearson correlation coefficients were used to determine the relationships between different measurements of propulsion versus walking speed as well as changes in propulsion versus changes in walking speed. Stepwise linear regression was used to determine which measurement of propulsion best predicted walking speed and changes in walking speed. The results showed that all 3 measurements of propulsion were correlated to walking speed, with peak propulsive force showed the strongest correlation. Similarly, when participants increased their walking speeds, changes in peak propulsive forces showed the strongest correlation to changes in walking speed. In addition, multiplying each measurement by cadence improved the correlations. The present study suggests that measuring peak propulsive force and cadence may be most appropriate of the variables studied to characterize propulsion in individuals poststroke. Copyright © 2016 Elsevier Ltd. All rights reserved.

Basic numerical processing, calculation, and working memory in children with dyscalculia and/or ADHD symptoms.

PubMed

Kuhn, Jörg-Tobias; Ise, Elena; Raddatz, Julia; Schwenk, Christin; Dobel, Christian

2016-09-01

Deficits in basic numerical skills, calculation, and working memory have been found in children with developmental dyscalculia (DD) as well as children with attention-deficit/hyperactivity disorder (ADHD). This paper investigates cognitive profiles of children with DD and/or ADHD symptoms (AS) in a double dissociation design to obtain a better understanding of the comorbidity of DD and ADHD. Children with DD-only (N = 33), AS-only (N = 16), comorbid DD+AS (N = 20), and typically developing controls (TD, N = 40) were assessed on measures of basic numerical processing, calculation, working memory, processing speed, and neurocognitive measures of attention. Children with DD (DD, DD+AS) showed deficits in all basic numerical skills, calculation, working memory, and sustained attention. Children with AS (AS, DD+AS) displayed more selective difficulties in dot enumeration, subtraction, verbal working memory, and processing speed. Also, they generally performed more poorly in neurocognitive measures of attention, especially alertness. Children with DD+AS mostly showed an additive combination of the deficits associated with DD-only and A_Sonly, except for subtraction tasks, in which they were less impaired than expected. DD and AS appear to be related to largely distinct patterns of cognitive deficits, which are present in combination in children with DD+AS.

Acoustic measurements for the combustion diagnosis of diesel engines fuelled with biodiesels

NASA Astrophysics Data System (ADS)

Zhen, Dong; Wang, Tie; Gu, Fengshou; Tesfa, Belachew; Ball, Andrew

2013-05-01

In this paper, an experimental investigation was carried out on the combustion process of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The effects of biodiesel on the combustion process and engine dynamics were analysed for non-intrusive combustion diagnosis based on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine. The signals of vibration, acoustic and in-cylinder pressure were measured simultaneously to find their inter-connection for diagnostic feature extraction. It was found that the sound energy level increases with the increase of engine load and speed, and the sound characteristics are closely correlated with the variation of in-cylinder pressure and combustion process. The continuous wavelet transform (CWT) was employed to analyse the non-stationary nature of engine noise in a higher frequency range. Before the wavelet analysis, time synchronous average (TSA) was used to enhance the signal-to-noise ratio (SNR) of the acoustic signal by suppressing the components which are asynchronous. Based on the root mean square (RMS) values of CWT coefficients, the effects of biodiesel fractions and operating conditions (speed and load) on combustion process and engine dynamics were investigated. The result leads to the potential of airborne acoustic measurements and analysis for engine condition monitoring and fuel quality evaluation.

PATTERNS OF CLINICALLY SIGNIFICANT COGNITIVE IMPAIRMENT IN HOARDING DISORDER.

PubMed

Mackin, R Scott; Vigil, Ofilio; Insel, Philip; Kivowitz, Alana; Kupferman, Eve; Hough, Christina M; Fekri, Shiva; Crothers, Ross; Bickford, David; Delucchi, Kevin L; Mathews, Carol A

2016-03-01

The cognitive characteristics of individuals with hoarding disorder (HD) are not well understood. Existing studies are relatively few and somewhat inconsistent but suggest that individuals with HD may have specific dysfunction in the cognitive domains of categorization, speed of information processing, and decision making. However, there have been no studies evaluating the degree to which cognitive dysfunction in these domains reflects clinically significant cognitive impairment (CI). Participants included 78 individuals who met DSM-V criteria for HD and 70 age- and education-matched controls. Cognitive performance on measures of memory, attention, information processing speed, abstract reasoning, visuospatial processing, decision making, and categorization ability was evaluated for each participant. Rates of clinical impairment for each measure were compared, as were age- and education-corrected raw scores for each cognitive test. HD participants showed greater incidence of CI on measures of visual memory, visual detection, and visual categorization relative to controls. Raw-score comparisons between groups showed similar results with HD participants showing lower raw-score performance on each of these measures. In addition, in raw-score comparisons HD participants also demonstrated relative strengths compared to control participants on measures of verbal and visual abstract reasoning. These results suggest that HD is associated with a pattern of clinically significant CI in some visually mediated neurocognitive processes including visual memory, visual detection, and visual categorization. Additionally, these results suggest HD individuals may also exhibit relative strengths, perhaps compensatory, in abstract reasoning in both verbal and visual domains. © 2015 Wiley Periodicals, Inc.

Naming Speed of Adolescents and Young Adults with Attention Deficit Hyperactivity Disorder: Differences in Alphanumeric Versus Color/Object Naming.

PubMed

Whipple, Brittany D; Nelson, Jason M

2016-02-01

This study investigated the performance of adolescents and young adults with Attention Deficit Hyperactivity Disorder (ADHD), Reading Disorder (RD), and ADHD/RD on measures of alphanumeric and nonalphanumeric naming speed and the relationship between naming speed and academic achievement. The sample (N = 203) included students aged 17-28 years diagnosed with ADHD (n = 83), RD (n = 71), or ADHD/RD (n = 49). Individuals with ADHD performed significantly faster on measures of alphanumeric naming compared with RD and comorbid groups and, within group, demonstrated significantly quicker naming of letters/digits compared with colors/objects. Both alphanumeric rapid naming scores and processing speed scores variably predicted academic achievement scores across groups, whereas nonalphanumeric rapid naming only predicted reading comprehension scores within the ADHD group. Results support findings that older individuals with ADHD show relative weakness in rapid naming of objects and colors. Implications of these findings in regard to assessment of older individuals for ADHD are discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Wind-invariant saltation heights imply linear scaling of aeolian saltation flux with shear stress.

PubMed

Martin, Raleigh L; Kok, Jasper F

2017-06-01

Wind-driven sand transport generates atmospheric dust, forms dunes, and sculpts landscapes. However, it remains unclear how the flux of particles in aeolian saltation-the wind-driven transport of sand in hopping trajectories-scales with wind speed, largely because models do not agree on how particle speeds and trajectories change with wind shear velocity. We present comprehensive measurements, from three new field sites and three published studies, showing that characteristic saltation layer heights remain approximately constant with shear velocity, in agreement with recent wind tunnel studies. These results support the assumption of constant particle speeds in recent models predicting linear scaling of saltation flux with shear stress. In contrast, our results refute widely used older models that assume that particle speed increases with shear velocity, thereby predicting nonlinear 3/2 stress-flux scaling. This conclusion is further supported by direct field measurements of saltation flux versus shear stress. Our results thus argue for adoption of linear saltation flux laws and constant saltation trajectories for modeling saltation-driven aeolian processes on Earth, Mars, and other planetary surfaces.

Wind-invariant saltation heights imply linear scaling of aeolian saltation flux with shear stress

PubMed Central

Martin, Raleigh L.; Kok, Jasper F.

2017-01-01

Wind-driven sand transport generates atmospheric dust, forms dunes, and sculpts landscapes. However, it remains unclear how the flux of particles in aeolian saltation—the wind-driven transport of sand in hopping trajectories—scales with wind speed, largely because models do not agree on how particle speeds and trajectories change with wind shear velocity. We present comprehensive measurements, from three new field sites and three published studies, showing that characteristic saltation layer heights remain approximately constant with shear velocity, in agreement with recent wind tunnel studies. These results support the assumption of constant particle speeds in recent models predicting linear scaling of saltation flux with shear stress. In contrast, our results refute widely used older models that assume that particle speed increases with shear velocity, thereby predicting nonlinear 3/2 stress-flux scaling. This conclusion is further supported by direct field measurements of saltation flux versus shear stress. Our results thus argue for adoption of linear saltation flux laws and constant saltation trajectories for modeling saltation-driven aeolian processes on Earth, Mars, and other planetary surfaces. PMID:28630907

PSP Measurement of Stator Vane Surface Pressures in a High Speed Fan

NASA Technical Reports Server (NTRS)

Lepicovsky, Jan

1998-01-01

This paper presents measurements of static pressures on the stator vane suction side of a high-speed single stage fan using the technique of pressure sensitive paint (PSP). The paper illustrates development in application of the relatively new experimental technique to the complex environment of internal flows in turbomachines. First, there is a short explanation of the physics of the PSP technique and a discussion of calibration methods for pressure sensitive paint in the turbomachinery environment. A description of the image conversion process follows. The recorded image of the stator vane pressure field is skewed due to the limited optical access and must be converted to the meridional plane projection for comparison with analytical predictions. The experimental results for seven operating conditions along an off-design rotational speed line are shown in a concise form, including performance map points, mindspan static tap pressure distributions, and vane suction side pressure fields. Then, a comparison between static tap and pressure sensitive paint data is discussed. Finally, the paper lists shortcomings of the pressure sensitive paint technology and lessons learned in this high-speed fan application.

Wear-Induced Changes in FSW Tool Pin Profile: Effect of Process Parameters

NASA Astrophysics Data System (ADS)

Sahlot, Pankaj; Jha, Kaushal; Dey, G. K.; Arora, Amit

2018-06-01

Friction stir welding (FSW) of high melting point metallic (HMPM) materials has limited application due to tool wear and relatively short tool life. Tool wear changes the profile of the tool pin and adversely affects weld properties. A quantitative understanding of tool wear and tool pin profile is crucial to develop the process for joining of HMPM materials. Here we present a quantitative wear study of H13 steel tool pin profile for FSW of CuCrZr alloy. The tool pin profile is analyzed at multiple traverse distances for welding with various tool rotational and traverse speeds. The results indicate that measured wear depth is small near the pin root and significantly increases towards the tip. Near the pin tip, wear depth increases with increase in tool rotational speed. However, change in wear depth near the pin root is minimal. Wear depth also increases with decrease in tool traverse speeds. Tool pin wear from the bottom results in pin length reduction, which is greater for higher tool rotational speeds, and longer traverse distances. The pin profile changes due to wear and result in root defect for long traverse distance. This quantitative understanding of tool wear would be helpful to estimate tool wear, optimize process parameters, and tool pin shape during FSW of HMPM materials.

Ultrasonic sensing for noninvasive characterization of oil-water-gas flow in a pipe

NASA Astrophysics Data System (ADS)

Chillara, Vamshi Krishna; Sturtevant, Blake T.; Pantea, Cristian; Sinha, Dipen N.

2017-02-01

A technique for noninvasive ultrasonic characterization of multiphase crude oil-water-gas flow is discussed. The proposed method relies on determining the sound speed in the mixture. First, important issues associated with making real-time noninvasive measurements are discussed. Then, signal processing approach adopted to determine the sound speed in the multiphase mixture is presented. Finally, results from controlled experiments on crude oil-water mixture in both the presence and absence of gas are presented.

Unstable behaviour of RPT when testing turbine characteristics in the laboratory

NASA Astrophysics Data System (ADS)

Nielsen, T. K.; Fjørtoft Svarstad, M.

2014-03-01

A reversible pump turbine is a machine that can operate in three modes of operation i.e. in pumping mode. in turbine mode and in phase compensating mode (idle speed). Reversible pump turbines have an increasing importance for regulation purposes for obtaining power balance in electric power systems. Especially in grids dominated by thermal energy. reversible pump turbines improve the overall power regulating ability. Increased use of renewables (wind-. wave- and tidal power plants) will utterly demand better regulation ability of the traditional water power systems. enhancing the use of reversible pump turbines. A reversible pump turbine is known for having incredible steep speed - flow characteristics. As the speed increases the flow decreases more than that of a Francis turbines with the same specific speed. The steep characteristics might cause severe stability problems in turbine mode of operation. Stability in idle speed is a necessity for phasing in the generator to the electric grid. In the design process of a power plant. system dynamic simulations must be performed in order to check the system stability. The turbine characteristics will have to be modelled with certain accuracy even before one knows the exact turbine design and have measured characteristics. A representation of the RPT characteristics for system dynamic simulation purposes is suggested and compared with measured characteristics. The model shows good agreement with RPT characteristics measured in The Waterpower Laboratory. Because of the S-shaped characteristics. there is a stability issue involved when measuring these characteristics. Without special measures. it is impossible to achieve stable conditions in certain operational points. The paper discusses the mechanism when using a throttle to achieve system stability. even if the turbine characteristics imply instability.

Study on the mechanical analysis and the testing technology of the optical fiber cables released from the bobbin

NASA Astrophysics Data System (ADS)

Wang, Rong; Li, Zhen-hua; Bian, Bao-min; Liu, Cheng-lin; Ji, Yun-jing

2014-12-01

Accurate measurements of forces applied to the optical cable reels with high spinning speeds, will render information on the breakdown of optical fibers, and thus improve the odds of success and un-winding efficiency. In this paper we analyze and deduce the cable wire stress at high pay-off speeds. A high-sensitive opti-mechanical testing sensory device is designed to measure both the axial tension of the cables and the radial pressure of the cable reels at varying stress points simultaneously. The time resolution of this new device is less than 0.015ms, the response time is up to 15μs, and its sensitivity is about 500pc/N, which satisfies the mechanical testing requirements at high spinning speeds. In addition, the spinning speed of 260m/s led to the break-down of the optical fibers, and the spinning speed of 250m/s tested finally led to a deceleration near the end of the broken fibers. It is obvious that this kit can meet the requirement to obtain the periodic signals of the varying forces for each layer and each turn of optical fiber cables. Moreover, we found that the pay-off fiber cable is safe with the unwinding speed of 250m/s and the break-down of optical cables happens during the deceleration process. However, it is under the unwinding speed of 260m/s that pay-off fiber cables broke during the experiment. The abnormal breakdown signals are captured at these unwinding speeds, respectively.

RAYLEIGH–TAYLOR UNSTABLE FLAMES—FAST OR FASTER?

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

Hicks, E. P., E-mail: eph2001@columbia.edu

2015-04-20

Rayleigh–Taylor (RT) unstable flames play a key role in the explosions of supernovae Ia. However, the dynamics of these flames are still not well understood. RT unstable flames are affected by both the RT instability of the flame front and by RT-generated turbulence. The coexistence of these factors complicates the choice of flame speed subgrid models for full-star Type Ia simulations. Both processes can stretch and wrinkle the flame surface, increasing its area and, therefore, the burning rate. In past research, subgrid models have been based on either the RT instability or turbulence setting the flame speed. We evaluate bothmore » models, checking their assumptions and their ability to correctly predict the turbulent flame speed. Specifically, we analyze a large parameter study of 3D direct numerical simulations of RT unstable model flames. This study varies both the simulation domain width and the gravity in order to probe a wide range of flame behaviors. We show that RT unstable flames are different from traditional turbulent flames: they are thinner rather than thicker when turbulence is stronger. We also show that none of the several different types of turbulent flame speed models accurately predicts measured flame speeds. In addition, we find that the RT flame speed model only correctly predicts the measured flame speed in a certain parameter regime. Finally, we propose that the formation of cusps may be the factor causing the flame to propagate more quickly than predicted by the RT model.« less

Rayleigh-Taylor Unstable Flames -- Fast or Faster?

NASA Astrophysics Data System (ADS)

Hicks, E. P.

2015-04-01

Rayleigh-Taylor (RT) unstable flames play a key role in the explosions of supernovae Ia. However, the dynamics of these flames are still not well understood. RT unstable flames are affected by both the RT instability of the flame front and by RT-generated turbulence. The coexistence of these factors complicates the choice of flame speed subgrid models for full-star Type Ia simulations. Both processes can stretch and wrinkle the flame surface, increasing its area and, therefore, the burning rate. In past research, subgrid models have been based on either the RT instability or turbulence setting the flame speed. We evaluate both models, checking their assumptions and their ability to correctly predict the turbulent flame speed. Specifically, we analyze a large parameter study of 3D direct numerical simulations of RT unstable model flames. This study varies both the simulation domain width and the gravity in order to probe a wide range of flame behaviors. We show that RT unstable flames are different from traditional turbulent flames: they are thinner rather than thicker when turbulence is stronger. We also show that none of the several different types of turbulent flame speed models accurately predicts measured flame speeds. In addition, we find that the RT flame speed model only correctly predicts the measured flame speed in a certain parameter regime. Finally, we propose that the formation of cusps may be the factor causing the flame to propagate more quickly than predicted by the RT model.

Thermocouple and infrared sensor-based measurement of temperature distribution in metal cutting.

PubMed

Kus, Abdil; Isik, Yahya; Cakir, M Cemal; Coşkun, Salih; Özdemir, Kadir

2015-01-12

In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining.

Thermocouple and Infrared Sensor-Based Measurement of Temperature Distribution in Metal Cutting

PubMed Central

Kus, Abdil; Isik, Yahya; Cakir, M. Cemal; Coşkun, Salih; Özdemir, Kadir

2015-01-01

In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining. PMID:25587976

A phase-based stereo vision system-on-a-chip.

PubMed

Díaz, Javier; Ros, Eduardo; Sabatini, Silvio P; Solari, Fabio; Mota, Sonia

2007-02-01

A simple and fast technique for depth estimation based on phase measurement has been adopted for the implementation of a real-time stereo system with sub-pixel resolution on an FPGA device. The technique avoids the attendant problem of phase warping. The designed system takes full advantage of the inherent processing parallelism and segmentation capabilities of FPGA devices to achieve a computation speed of 65megapixels/s, which can be arranged with a customized frame-grabber module to process 211frames/s at a size of 640x480 pixels. The processing speed achieved is higher than conventional camera frame rates, thus allowing the system to extract multiple estimations and be used as a platform to evaluate integration schemes of a population of neurons without increasing hardware resource demands.

Hippocampal structure and human cognition: key role of spatial processing and evidence supporting the efficiency hypothesis in females

PubMed Central

Colom, Roberto; Stein, Jason L.; Rajagopalan, Priya; Martínez, Kenia; Hermel, David; Wang, Yalin; Álvarez-Linera, Juan; Burgaleta, Miguel; Quiroga, MªÁngeles; Shih, Pei Chun; Thompson, Paul M.

2014-01-01

Here we apply a method for automated segmentation of the hippocampus in 3D high-resolution structural brain MRI scans. One hundred and four healthy young adults completed twenty one tasks measuring abstract, verbal, and spatial intelligence, along with working memory, executive control, attention, and processing speed. After permutation tests corrected for multiple comparisons across vertices (p < .05) significant relationships were found for spatial intelligence, spatial working memory, and spatial executive control. Interactions with sex revealed significant relationships with the general factor of intelligence (g), along with abstract and spatial intelligence. These correlations were mainly positive for males but negative for females, which might support the efficiency hypothesis in women. Verbal intelligence, attention, and processing speed were not related to hippocampal structural differences. PMID:25632167

Experimental analysis of IMEP in a rotary combustion engine. [Indicated Mean Effective Pressure

NASA Technical Reports Server (NTRS)

Schock, H. J.; Rice, W. J.; Meng, P. R.

1981-01-01

This experimental work demonstrates the use of a NASA designed, real time Indicated Mean Effective Pressure (IMEP) measurement system which will be used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate the volume function in real time. Measurements at two engine speeds (2000 and 3000 RPM) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 RPM.

Precision depth measurement of through silicon vias (TSVs) on 3D semiconductor packaging process.

PubMed

Jin, Jonghan; Kim, Jae Wan; Kang, Chu-Shik; Kim, Jong-Ahn; Lee, Sunghun

2012-02-27

We have proposed and demonstrated a novel method to measure depths of through silicon vias (TSVs) at high speed. TSVs are fine and deep holes fabricated in silicon wafers for 3D semiconductors; they are used for electrical connections between vertically stacked wafers. Because the high-aspect ratio hole of the TSV makes it difficult for light to reach the bottom surface, conventional optical methods using visible lights cannot determine the depth value. By adopting an optical comb of a femtosecond pulse laser in the infra-red range as a light source, the depths of TSVs having aspect ratio of about 7 were measured. This measurement was done at high speed based on spectral resolved interferometry. The proposed method is expected to be an alternative method for depth inspection of TSVs.

Viscoelastic material properties' identification using high speed full field measurements on vibrating plates

NASA Astrophysics Data System (ADS)

Giraudeau, A.; Pierron, F.

2010-06-01

The paper presents an experimental application of a method leading to the identification of the elastic and damping material properties of isotropic vibrating plates. The theory assumes that the searched parameters can be extracted from curvature and deflection fields measured on the whole surface of the plate at two particular instants of the vibrating motion. The experimental application consists in an original excitation fixture, a particular adaptation of an optical full-field measurement technique, a data preprocessing giving the curvature and deflection fields and finally in the identification process using the Virtual Fields Method (VFM). The principle of the deflectometry technique used for the measurements is presented. First results of identification on an acrylic plate are presented and compared to reference values. Details about a new experimental arrangement, currently in progress, is presented. It uses a high speed digital camera to over sample the full-field measurements.

Measurement of stress distributions in truck tyre contact patch in real rolling conditions

NASA Astrophysics Data System (ADS)

Anghelache, Gabriel; Moisescu, Raluca

2012-12-01

Stress distributions on three orthogonal directions have been measured across the contact patch of truck tyres using the complex measuring system that contains a transducer assembly with 30 sensing elements placed in the road surface. The measurements have been performed in straight line, in real rolling conditions. Software applications for calibration, data acquisition, and data processing were developed. The influence of changes in inflation pressure and rolling speed on the shapes and sizes of truck tyre contact patch has been shown. The shapes and magnitudes of normal, longitudinal, and lateral stress distributions, measured at low speed, have been presented and commented. The effect of wheel toe-in and camber on the stress distribution results was observed. The paper highlights the impact of the longitudinal tread ribs on the shear stress distributions. The ratios of stress distributions in the truck tyre contact patch have been computed and discussed.

Measuring and imaging diffusion with multiple scan speed image correlation spectroscopy.

PubMed

Gröner, Nadine; Capoulade, Jérémie; Cremer, Christoph; Wachsmuth, Malte

2010-09-27

The intracellular mobility of biomolecules is determined by transport and diffusion as well as molecular interactions and is crucial for many processes in living cells. Methods of fluorescence microscopy like confocal laser scanning microscopy (CLSM) can be used to characterize the intracellular distribution of fluorescently labeled biomolecules. Fluorescence correlation spectroscopy (FCS) is used to describe diffusion, transport and photo-physical processes quantitatively. As an alternative to FCS, spatially resolved measurements of mobilities can be implemented using a CLSM by utilizing the spatio-temporal information inscribed into the image by the scan process, referred to as raster image correlation spectroscopy (RICS). Here we present and discuss an extended approach, multiple scan speed image correlation spectroscopy (msICS), which benefits from the advantages of RICS, i.e. the use of widely available instrumentation and the extraction of spatially resolved mobility information, without the need of a priori knowledge of diffusion properties. In addition, msICS covers a broad dynamic range, generates correlation data comparable to FCS measurements, and allows to derive two-dimensional maps of diffusion coefficients. We show the applicability of msICS to fluorophores in solution and to free EGFP in living cells.

Superfast 3D shape measurement of a flapping flight process with motion based segmentation

NASA Astrophysics Data System (ADS)

Li, Beiwen

2018-02-01

Flapping flight has drawn interests from different fields including biology, aerodynamics and robotics. For such research, the digital fringe projection technology using defocused binary image projection has superfast (e.g. several kHz) measurement capabilities with digital-micromirror-device, yet its measurement quality is still subject to the motion of flapping flight. This research proposes a novel computational framework for dynamic 3D shape measurement of a flapping flight process. The fast and slow motion parts are separately reconstructed with Fourier transform and phase shifting. Experiments demonstrate its success by measuring a flapping wing robot (image acquisition rate: 5000 Hz; flapping speed: 25 cycles/second).

Repeated head trauma is associated with smaller thalamic volumes and slower processing speed: the Professional Fighters’ Brain Health Study

PubMed Central

Bernick, Charles; Banks, Sarah J; Shin, Wanyong; Obuchowski, Nancy; Butler, Sam; Noback, Michael; Phillips, Michael; Lowe, Mark; Jones, Stephen; Modic, Michael

2015-01-01

Objectives Cumulative head trauma may alter brain structure and function. We explored the relationship between exposure variables, cognition and MRI brain structural measures in a cohort of professional combatants. Methods 224 fighters (131 mixed martial arts fighters and 93 boxers) participating in the Professional Fighters Brain Health Study, a longitudinal cohort study of licensed professional combatants, were recruited, as were 22 controls. Each participant underwent computerised cognitive testing and volumetric brain MRI. Fighting history including years of fighting and fights per year was obtained from self-report and published records. Statistical analyses of the baseline evaluations were applied cross-sectionally to determine the relationship between fight exposure variables and volumes of the hippocampus, amygdala, thalamus, caudate, putamen. Moreover, the relationship between exposure and brain volumes with cognitive function was assessed. Results Increasing exposure to repetitive head trauma measured by number of professional fights, years of fighting, or a Fight Exposure Score (FES) was associated with lower brain volumes, particularly the thalamus and caudate. In addition, speed of processing decreased with decreased thalamic volumes and with increasing fight exposure. Higher scores on a FES used to reflect exposure to repetitive head trauma were associated with greater likelihood of having cognitive impairment. Conclusions Greater exposure to repetitive head trauma is associated with lower brain volumes and lower processing speed in active professional fighters. PMID:25633832

Musical practice and cognitive aging: two cross-sectional studies point to phonemic fluency as a potential candidate for a use-dependent adaptation.

PubMed

Fauvel, Baptiste; Groussard, Mathilde; Mutlu, Justine; Arenaza-Urquijo, Eider M; Eustache, Francis; Desgranges, Béatrice; Platel, Hervé

2014-01-01

Because of permanent use-dependent brain plasticity, all lifelong individuals' experiences are believed to influence the cognitive aging quality. In older individuals, both former and current musical practices have been associated with better verbal skills, visual memory, processing speed, and planning function. This work sought for an interaction between musical practice and cognitive aging by comparing musician and non-musician individuals for two lifetime periods (middle and late adulthood). Long-term memory, auditory-verbal short-term memory, processing speed, non-verbal reasoning, and verbal fluencies were assessed. In Study 1, measures of processing speed and auditory-verbal short-term memory were significantly better performed by musicians compared with controls, but both groups displayed the same age-related differences. For verbal fluencies, musicians scored higher than controls and displayed different age effects. In Study 2, we found that lifetime period at training onset (childhood vs. adulthood) was associated with phonemic, but not semantic, fluency performances (musicians who had started to practice in adulthood did not perform better on phonemic fluency than non-musicians). Current frequency of training did not account for musicians' scores on either of these two measures. These patterns of results are discussed by setting the hypothesis of a transformative effect of musical practice against a non-causal explanation.

High Rotation Speed Friction Stir Welding for 2014 Aluminum Alloy Thin Sheets

NASA Astrophysics Data System (ADS)

Chen, Shujin; Zhou, Yang; Xue, Junrong; Ni, Ruiyang; Guo, Yue; Dong, Jianghui

2017-03-01

In this study, 2014 aluminum alloy sheets with 1 mm thickness are welded successfully by friction stir welding (FSW) robot under the condition of high rotation speed. When the high rotation speed of 10,000-16,500 rpm is applied, the lower axial pressure (less than 200 N) is obtained, which reduces stiffness requirements for equipment. Welding deformation is inevitable because high rotation speed can easily result in rapid heating rate and uneven heat input. The welding distortion caused by two cooling methods is measured, respectively, by laser range finder. The experimental results show that the welding distortion is smaller under the condition of water cooling. When the rotation speed is up to 15,000 rpm and welding speed 50-170 mm/min, the whole welding process is controllable. Under the higher rotation speed condition, the welding defects disappear gradually and more stable mechanical properties can be obtained up to 75% of base metal (ω = 16,000 rpm, ν = 110 mm/min). The results of different welding parameters demonstrate that the high rotation speed can increase material mixing and reduce the axial force (z force), and it can benefit lightweight sheet welding by using FSW robot.

Advanced Digital Signal Processing for Hybrid Lidar

DTIC Science & Technology

2014-09-30

with a PC running LabVIEW performing the final calculations to obtain range measurements . A MATLAB- based system developed at Clarkson University in...the image contrast and resolution as well as the object ranging measurement accuracy. There have been various methods that attempt to reduce the...high speed modulation to help suppress backscatter while also providing an unambiguous range measurement . In general, it is desired to determine which

Wind Speed and Sea State Dependencies of Air-Sea Gas Transfer: Results From the High Wind Speed Gas Exchange Study (HiWinGS)

NASA Astrophysics Data System (ADS)

Blomquist, B. W.; Brumer, S. E.; Fairall, C. W.; Huebert, B. J.; Zappa, C. J.; Brooks, I. M.; Yang, M.; Bariteau, L.; Prytherch, J.; Hare, J. E.; Czerski, H.; Matei, A.; Pascal, R. W.

2017-10-01

A variety of physical mechanisms are jointly responsible for facilitating air-sea gas transfer through turbulent processes at the atmosphere-ocean interface. The nature and relative importance of these mechanisms evolves with increasing wind speed. Theoretical and modeling approaches are advancing, but the limited quantity of observational data at high wind speeds hinders the assessment of these efforts. The HiWinGS project successfully measured gas transfer coefficients (k660) with coincident wave statistics under conditions with hourly mean wind speeds up to 24 m s-1 and significant wave heights to 8 m. Measurements of k660 for carbon dioxide (CO2) and dimethylsulfide (DMS) show an increasing trend with respect to 10 m neutral wind speed (U10N), following a power law relationship of the form: k660 CO2˜U10N1.68 and k660 dms˜U10N1.33. Among seven high wind speed events, CO2 transfer responded to the intensity of wave breaking, which depended on both wind speed and sea state in a complex manner, with k660 CO2 increasing as the wind sea approaches full development. A similar response is not observed for DMS. These results confirm the importance of breaking waves and bubble injection mechanisms in facilitating CO2 transfer. A modified version of the Coupled Ocean-Atmosphere Response Experiment Gas transfer algorithm (COAREG ver. 3.5), incorporating a sea state-dependent calculation of bubble-mediated transfer, successfully reproduces the mean trend in observed k660 with wind speed for both gases. Significant suppression of gas transfer by large waves was not observed during HiWinGS, in contrast to results from two prior field programs.

A novel five-wire micro anemometer with 3D directionality for low speed air flow detection and acoustic particle velocity detecting capability

NASA Astrophysics Data System (ADS)

Li, Zhe; Chang, Wenhan; Gao, Chengchen; Hao, Yilong

2018-04-01

In this paper, a novel five-wire micro-fabricated anemometer with 3D directionality based on calorimetric principle is proposed, which is capable of measuring low speed airflow. This structure is realized by vertically bonding two different dies, which can be fabricated on the same wafer resulting in a simple fabrication process. Experiments on speed lower than 200 mm s-1 are conducted, showing good repeatability and directionality. The speed of airflow is controlled by the volumetric flow rate. The measured velocity sensitivity is 9.4 mV · s m-1, with relative direction sensitivity of 37.1 dB. The deviation between the expected and the measured directivity is analyzed by both theories and simulations. A correction procedure is proposed and turns out to be useful to eliminate this deviation. To further explore the potential of our device, we expose it to acoustic plane waves in a standing wave tube, showing consistent planar directivity of figure of eight. The measured velocity sensitivity at 1 kHz and 120 dBC is 4.4 mV · s m-1, with relative direction sensitivity of 27.0 dB. By using the correction method proposed above, the maximum angle error is about  ±2°, showing its good directionality accuracy.

Phonological Processing Skills as Predictors of Literacy amongst Arabic Speaking Bahraini Children

ERIC Educational Resources Information Center

al Mannai, Haya; Everatt, John

2005-01-01

This paper reports a study of the reading and spelling skills of grades 1-3 Arabic-speaking children in Bahrain. Children were tested on their literacy skills (single word reading and spelling), their ability to decode letter strings (non-word reading) and measures of phonological awareness, short-term memory, speed of processing and non-verbal…

RysannMD: A biomedical semantic annotator balancing speed and accuracy.

PubMed

Cuzzola, John; Jovanović, Jelena; Bagheri, Ebrahim

2017-07-01

Recently, both researchers and practitioners have explored the possibility of semantically annotating large and continuously evolving collections of biomedical texts such as research papers, medical reports, and physician notes in order to enable their efficient and effective management and use in clinical practice or research laboratories. Such annotations can be automatically generated by biomedical semantic annotators - tools that are specifically designed for detecting and disambiguating biomedical concepts mentioned in text. The biomedical community has already presented several solid automated semantic annotators. However, the existing tools are either strong in their disambiguation capacity, i.e., the ability to identify the correct biomedical concept for a given piece of text among several candidate concepts, or they excel in their processing time, i.e., work very efficiently, but none of the semantic annotation tools reported in the literature has both of these qualities. In this paper, we present RysannMD (Ryerson Semantic Annotator for Medical Domain), a biomedical semantic annotation tool that strikes a balance between processing time and performance while disambiguating biomedical terms. In other words, RysannMD provides reasonable disambiguation performance when choosing the right sense for a biomedical term in a given context, and does that in a reasonable time. To examine how RysannMD stands with respect to the state of the art biomedical semantic annotators, we have conducted a series of experiments using standard benchmarking corpora, including both gold and silver standards, and four modern biomedical semantic annotators, namely cTAKES, MetaMap, NOBLE Coder, and Neji. The annotators were compared with respect to the quality of the produced annotations measured against gold and silver standards using precision, recall, and F 1 measure and speed, i.e., processing time. In the experiments, RysannMD achieved the best median F 1 measure across the benchmarking corpora, independent of the standard used (silver/gold), biomedical subdomain, and document size. In terms of the annotation speed, RysannMD scored the second best median processing time across all the experiments. The obtained results indicate that RysannMD offers the best performance among the examined semantic annotators when both quality of annotation and speed are considered simultaneously. Copyright © 2017 Elsevier Inc. All rights reserved.

High-speed real-time 3-D coordinates measurement based on fringe projection profilometry considering camera lens distortion

NASA Astrophysics Data System (ADS)

Feng, Shijie; Chen, Qian; Zuo, Chao; Sun, Jiasong; Yu, Shi Ling

2014-10-01

Optical three-dimensional (3-D) profilometry is gaining increasing attention for its simplicity, flexibility, high accuracy, and non-contact nature. Recent advances in imaging sensors and digital projection technology further its progress in high-speed, real-time applications, enabling 3-D shapes reconstruction of moving objects and dynamic scenes. However, the camera lens is never perfect and the lens distortion does influence the accuracy of the measurement result, which is often overlooked in the existing real-time 3-D shape measurement systems. To this end, here we present a novel high-speed real-time 3-D coordinates measuring technique based on fringe projection with the consideration of the camera lens distortion. A pixel mapping relation between a distorted image and a corrected one is pre-determined and stored in computer memory for real-time fringe correction. The out-of-plane height is obtained firstly and the acquisition for the two corresponding in-plane coordinates follows on the basis of the solved height. Besides, a method of lookup table (LUT) is introduced as well for fast data processing. Our experimental results reveal that the measurement error of the in-plane coordinates has been reduced by one order of magnitude and the accuracy of the out-plane coordinate been tripled after the distortions being eliminated. Moreover, owing to the generated LUTs, a 3-D reconstruction speed of 92.34 frames per second can be achieved.

Article 7: Measures of digit span and verbal rehearsal speed in deaf children following more than 10 years of cochlear implantation

PubMed Central

Pisoni, David; Kronenberger, William; Roman, Adrienne; Geers, Ann

2011-01-01

Precis This paper reports results on the development of immediate memory capacity and verbal rehearsal speed in 112 children with more than ten years of CI use. We found less than half of the sample showed increases in both forward and backward digit spans suggesting disturbances in basic mechanisms related to storage or rehearsal of verbal information. Both spans and verbal rehearsal speeds in elementary school were found to be correlated with speech and language outcomes in high school. These developmental results provide new insights in the elementary neurocognitive information processes associated with high variability in speech and language outcomes. PMID:21832890

Shared virtual memory and generalized speedup

NASA Technical Reports Server (NTRS)

Sun, Xian-He; Zhu, Jianping

1994-01-01

Generalized speedup is defined as parallel speed over sequential speed. The generalized speedup and its relation with other existing performance metrics, such as traditional speedup, efficiency, scalability, etc., are carefully studied. In terms of the introduced asymptotic speed, it was shown that the difference between the generalized speedup and the traditional speedup lies in the definition of the efficiency of uniprocessor processing, which is a very important issue in shared virtual memory machines. A scientific application was implemented on a KSR-1 parallel computer. Experimental and theoretical results show that the generalized speedup is distinct from the traditional speedup and provides a more reasonable measurement. In the study of different speedups, various causes of superlinear speedup are also presented.

Sensory Gating Deficits in First-Episode Psychosis: Evidence From Neurophysiology, Psychophysiology, and Neuropsychology.

PubMed

Morales-Muñoz, Isabel; Jurado-Barba, Rosa; Fernández-Guinea, Sara; Rodríguez-Jiménez, Roberto; Jiménez-Arriero, Miguel Ángel; Criado, José R; Rubio, Gabriel

2016-12-01

Sensory gating deficits are commonly found in patients with schizophrenia. However, there is still scarce research on this issue. Thirty-eight patients with first-episode psychosis (FEP) were compared to thirty-eight controls. A condition-test paradigm of event-related potentials (ERP), prepulse inhibition (PPI), and some specific tasks of the MATRICS Consensus Cognitive Battery (MCCB) were used (i.e., TMT, BACS-SC, and Fluency for processing speed and CPT-IP for attention and vigilance). The ERP components measured were P50, N1, and P2. The PPI intervals examined were 30, 60, and 120 msec. Regarding the MCCB, processing speed and attention/vigilance cognitive domains were selected. FEP patients showed significant deficits in N1 and P2 components, at 30 and 60 PPI levels and in all the MCCB subtests selected. We obtained significant relationships in N1 with PPI-60, and with one MCCB subtest for processing speed. In addition, this same subtest showed significant association with P2. Therefore, sensory gating functioning is widely impaired since the very early stages of schizophrenia.

INDIVIDUAL DIFFERENCES IN TASK-SPECIFIC PAIRED ASSOCIATES LEARNING IN OLDER ADULTS: THE ROLE OF PROCESSING SPEED AND WORKING MEMORY

PubMed Central

Kurtz, Tanja; Mogle, Jacqueline; Sliwinski, Martin J.; Hofer, Scott M.

2013-01-01

Background The role of processing speed and working memory was investigated in terms of individual differences in task-specific paired associates learning in a sample of older adults. Task-specific learning, as distinct from content-oriented item-specific learning, refers to gains in performance due to repeated practice on a learning task in which the to-be-learned material changes over trials. Methods Learning trajectories were modeled within an intensive repeated-measures design based on participants obtained from an opt-in internet-based sampling service (Mage = 65.3, SD = 4.81). Participants completed an eight-item paired associates task daily over a seven-day period. Results Results indicated that a three-parameter hyperbolic model (i.e., initial level, learning rate, and asymptotic performance) best described learning trajectory. After controlling for age-related effects, both higher working memory and higher processing speed had a positive effect on all three learning parameters. Conclusion These results emphasize the role of cognitive abilities for individual differences in task-specific learning of older adults. PMID:24151913

Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction

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

Zhao, Cang; Fezzaa, Kamel; Cunningham, Ross W.

Here, we employ the high-speed synchrotron hard X-ray imaging and diffraction techniques to monitor the laser powder bed fusion (LPBF) process of Ti-6Al-4V in situ and in real time. We demonstrate that many scientifically and technologically significant phenomena in LPBF, including melt pool dynamics, powder ejection, rapid solidification, and phase transformation, can be probed with unprecedented spatial and temporal resolutions. In particular, the keyhole pore formation is experimentally revealed with high spatial and temporal resolutions. The solidification rate is quantitatively measured, and the slowly decrease in solidification rate during the relatively steady state could be a manifestation of the recalescencemore » phenomenon. The high-speed diffraction enables a reasonable estimation of the cooling rate and phase transformation rate, and the diffusionless transformation from β to α’ phase is evident. The data present here will facilitate the understanding of dynamics and kinetics in metal LPBF process, and the experiment platform established will undoubtedly become a new paradigm for future research and development of metal additive manufacturing.« less

Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction

DOE PAGES

Zhao, Cang; Fezzaa, Kamel; Cunningham, Ross W.; ...

2017-06-15

Here, we employ the high-speed synchrotron hard X-ray imaging and diffraction techniques to monitor the laser powder bed fusion (LPBF) process of Ti-6Al-4V in situ and in real time. We demonstrate that many scientifically and technologically significant phenomena in LPBF, including melt pool dynamics, powder ejection, rapid solidification, and phase transformation, can be probed with unprecedented spatial and temporal resolutions. In particular, the keyhole pore formation is experimentally revealed with high spatial and temporal resolutions. The solidification rate is quantitatively measured, and the slowly decrease in solidification rate during the relatively steady state could be a manifestation of the recalescencemore » phenomenon. The high-speed diffraction enables a reasonable estimation of the cooling rate and phase transformation rate, and the diffusionless transformation from β to α’ phase is evident. The data present here will facilitate the understanding of dynamics and kinetics in metal LPBF process, and the experiment platform established will undoubtedly become a new paradigm for future research and development of metal additive manufacturing.« less

Aging and the Vulnerability of Speech to Dual Task Demands

PubMed Central

Kemper, Susan; Schmalzried, RaLynn; Hoffman, Lesa; Herman, Ruth

2010-01-01

Tracking a digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. Tracking performance by both groups was affected by dual task demands: time on target declined and tracking error increased as dual task demands increased from the baseline condition to a moderately demanding dual task condition to a more demanding dual task condition. When dual task demands were moderate, older adults’ speech rate declined but their fluency, grammatical complexity, and content were unaffected. When the dual task was more demanding, older adults’ speech, like young adults’ speech, became highly fragmented, ungrammatical, and incoherent. Vocabulary, working memory, processing speed, and inhibition affected vulnerability to dual task costs: vocabulary provided some protection for sentence length and grammaticality, working memory conferred some protection for grammatical complexity, and processing speed provided some protection for speech rate, propositional density, coherence, and lexical diversity. Further, vocabulary and working memory capacity provided more protection for older adults than for young adults although the protective effect of processing speed was somewhat reduced for older adults as compared to the young adults. PMID:21186917

[Dose and image quality in intraoral radiography].

PubMed

Hjardemaal, O

1991-11-01

The technique factors when performing intraoral X-ray exposures must be selected in such a way that sufficient diagnostic information is obtained at a reasonable patient dose. The Danish National Institute of Radiation Hygiene has performed a study comprising 32 dental X-ray sets. The mean value of the skin dose for a maxillary molar was 9.6 mGy and the value for the dental colleges 7.0 mGy. For a mandibular incisor the corresponding doses were 7.7 mGy and 3.6 mGy. After the conclusion of the mentioned study it has been part of the institute's inspection procedure for dental X-ray sets to measure patient skin doses. 243 measurements were performed and the mean value of the entrance skin dose was 6.5 mGy and the dose interval was 0.7-57 mGy. All doses are normalised to speed class D film. At 16% of the inspected sets films of speed class E were used. The remainder used class D films. The spread in doses cannot be explained by variation in equipment parameters alone but is to a high degree due to a combination of inappropriate film processing and exposure time. Interviews with staff in dental clinics confirm that films are frequently processed until the desired density is obtained by visual estimation. It is shown that the skin dose when using film of speed class D can be kept below 7 mGy for a mandibular incisor. Concluding is stated that film processing shall be performed in accordance with specifications from the manufacturer of the developer. Film of speed class E must be used. Finally must the exposure time be graduated according to the object exposed.

Sodar - Vaisala Triton Wind Profiler, AON5 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON2 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON8 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON1 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON6 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON9 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON4 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON7 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Sodar - Vaisala Triton Wind Profiler, AON3 - Processed Data

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

Stoelinga, Mark

2018-01-26

This dataset contains measurements from eight different Vaisala Triton Wind Profiler instruments. The Triton Wind Profiler is a sodar wind profiler that measures wind speed, direction, and turbulence intensity at heights from 30 m to 200 m above ground every 10 minutes. The eight Tritons are located at various sites around the WFIP2 study area.

Reliability of a Computerized Neurocognitive Test in Baseline Concussion Testing of High School Athletes.

PubMed

MacDonald, James; Duerson, Drew

2015-07-01

Baseline assessments using computerized neurocognitive tests are frequently used in the management of sport-related concussions. Such testing is often done on an annual basis in a community setting. Reliability is a fundamental test characteristic that should be established for such tests. Our study examined the test-retest reliability of a computerized neurocognitive test in high school athletes over 1 year. Repeated measures design. Two American high schools. High school athletes (N = 117) participating in American football or soccer during the 2011-2012 and 2012-2013 academic years. All study participants completed 2 baseline computerized neurocognitive tests taken 1 year apart at their respective schools. The test measures performance on 4 cognitive tasks: identification speed (Attention), detection speed (Processing Speed), one card learning accuracy (Learning), and one back speed (Working Memory). Reliability was assessed by measuring the intraclass correlation coefficient (ICC) between the repeated measures of the 4 cognitive tasks. Pearson and Spearman correlation coefficients were calculated as a secondary outcome measure. The measure for identification speed performed best (ICC = 0.672; 95% confidence interval, 0.559-0.760) and the measure for one card learning accuracy performed worst (ICC = 0.401; 95% confidence interval, 0.237-0.542). All tests had marginal or low reliability. In a population of high school athletes, computerized neurocognitive testing performed in a community setting demonstrated low to marginal test-retest reliability on baseline assessments 1 year apart. Further investigation should focus on (1) improving the reliability of individual tasks tested, (2) controlling for external factors that might affect test performance, and (3) identifying the ideal time interval to repeat baseline testing in high school athletes. Computerized neurocognitive tests are used frequently in high school athletes, often within a model of baseline testing of asymptomatic individuals before the start of a sporting season. This study adds to the evidence that suggests in this population such testing may lack sufficient reliability to support clinical decision making.

Effect of grinding parameters on surface roughness and subsurface damage and their evaluation in fused silica.

PubMed

Xiao, Huapan; Chen, Zhi; Wang, Hairong; Wang, Jiuhong; Zhu, Nan

2018-02-19

Based on micro-indentation mechanics and kinematics of grinding processes, theoretical formulas are deduced to calculate surface roughness (SR) and subsurface damage (SSD) depth. The SRs and SSD depths of a series of fused silica samples, which are prepared under different grinding parameters, are measured. By experimental and theoretical analysis, the relationship between SR and SSD depth is discussed. The effect of grinding parameters on SR and SSD depth is investigated quantitatively. The results show that SR and SSD depth decrease with the increase of wheel speed or the decrease of feed speed as well as cutting depth. The interaction effect between wheel speed and feed speed should be emphasized greatly. Furthermore, a relationship model between SSD depth and grinding parameters is established, which could be employed to evaluate SSD depth efficiently.

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

Bunshah, R.F.; Shabaik, A.H.

The process of Activated Reactive Evaporation is used to synthesize superhard materials like carbides, oxides, nitrides and ultrafine grain cermets. The deposits are characterized by hardness, microstructure, microprobe analysis for chemistry and lattice parameter measurements. The synthesis and characterization of TiC-Ni cermets and Al/sub 2/O/sub 3/ are given. High speed steel tool coated with TiC, TiC-Ni and TaC are tested for machining performance at different speeds and feeds. The machining evaluation and the selection of coatings is based on the rate of deterioration of the coating tool temperature, and cutting forces. Tool life tests show coated high speed steel toolsmore » having 150 to 300% improvement in tool life compared to uncoated tools. Variability in the quality of the ground edge on high speed steel inserts produce a great scatter in the machining evaluation data.« less

High-speed high-accuracy three-dimensional shape measurement using digital binary defocusing method versus sinusoidal method

NASA Astrophysics Data System (ADS)

Hyun, Jae-Sang; Li, Beiwen; Zhang, Song

2017-07-01

This paper presents our research findings on high-speed high-accuracy three-dimensional shape measurement using digital light processing (DLP) technologies. In particular, we compare two different sinusoidal fringe generation techniques using the DLP projection devices: direct projection of computer-generated 8-bit sinusoidal patterns (a.k.a., the sinusoidal method), and the creation of sinusoidal patterns by defocusing binary patterns (a.k.a., the binary defocusing method). This paper mainly examines their performance on high-accuracy measurement applications under precisely controlled settings. Two different projection systems were tested in this study: a commercially available inexpensive projector and the DLP development kit. Experimental results demonstrated that the binary defocusing method always outperforms the sinusoidal method if a sufficient number of phase-shifted fringe patterns can be used.

32 CFR 634.27 - Speed-measuring devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 4 2011-07-01 2011-07-01 false Speed-measuring devices. 634.27 Section 634.27... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.27 Speed-measuring devices. Speed-measuring devices will be used in traffic control studies and enforcement programs. Signs...

The Involvement of Speed-of-Processing in Story Listening in Preschool Children: A Functional and Structural Connectivity Study.

PubMed

Horowitz-Kraus, Tzipi; Farah, Rola; DiFrancesco, Mark; Vannest, Jennifer

2017-02-01

Story listening in children relies on brain regions supporting speech perception, auditory word recognition, syntax, semantics, and discourse abilities, along with the ability to attend and process information (part of executive functions). Speed-of-processing is an early-developed executive function. We used functional and structural magnetic resonance imaging (MRI) to demonstrate the relationship between story listening and speed-of-processing in preschool-age children. Eighteen participants performed story-listening tasks during MRI scans. Functional and structural connectivity analysis was performed using the speed-of-processing scores as regressors. Activation in the superior frontal gyrus during story listening positively correlated with speed-of-processing scores. This region was functionally connected with the superior temporal gyrus, insula, and hippocampus. Fractional anisotropy in the inferior frontooccipital fasciculus, which connects the superior frontal and temporal gyri, was positively correlated with speed-of-processing scores. Our results suggest that speed-of-processing skills in preschool-age children are reflected in functional activation and connectivity during story listening and may act as a biomarker for future academic abilities. Georg Thieme Verlag KG Stuttgart · New York.

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

Holographic digital microscopy in on-line process control

NASA Astrophysics Data System (ADS)

Osanlou, Ardeshir

2011-09-01

This article investigates the feasibility of real-time three-dimensional imaging of microscopic objects within various emulsions while being produced in specialized production vessels. The study is particularly relevant to on-line process monitoring and control in chemical, pharmaceutical, food, cleaning, and personal hygiene industries. Such processes are often dynamic and the materials cannot be measured once removed from the production vessel. The technique reported here is applicable to three-dimensional characterization analyses on stirred fluids in small reaction vessels. Relatively expensive pulsed lasers have been avoided through the careful control of the speed of the moving fluid in relation to the speed of the camera exposure and the wavelength of the continuous wave laser used. The ultimate aim of the project is to introduce a fully robust and compact digital holographic microscope as a process control tool in a full size specialized production vessel.

Adapting ISA system warnings to enhance user acceptance.

PubMed

Jiménez, Felipe; Liang, Yingzhen; Aparicio, Francisco

2012-09-01

Inappropriate speed is a major cause of traffic accidents. Different measures have been considered to control traffic speed, and intelligent speed adaptation (ISA) systems are one of the alternatives. These systems know the speed limits and try to improve compliance with them. This paper deals with an informative ISA system that provides the driver with an advance warning before reaching a road section with singular characteristics that require a lower safe speed than the current speed. In spite of the extensive tests performed using ISA systems, few works show how warnings can be adapted to the driver. This paper describes a method to adapt warning parameters (safe speed on curves, zone of influence of a singular stretch, deceleration process and reaction time) to normal driving behavior. The method is based on a set of tests with and without the ISA system. This adjustment, as well as the analysis of driver acceptance before and after the adaptation and changes in driver behavior (changes in speed and path) resulting from the tested ISA regarding a driver's normal driving style, is shown in this paper. The main conclusion is that acceptance by drivers increased significantly after redefining the warning parameters, but the effect of speed homogenization was not reduced. Copyright © 2010 Elsevier Ltd. All rights reserved.

Rapid Automatized Naming in Children with Dyslexia: Is Inhibitory Control Involved?

PubMed

Bexkens, Anika; van den Wildenberg, Wery P M; Tijms, Jurgen

2015-08-01

Rapid automatized naming (RAN) is widely seen as an important indicator of dyslexia. The nature of the cognitive processes involved in rapid naming is however still a topic of controversy. We hypothesized that in addition to the involvement of phonological processes and processing speed, RAN is a function of inhibition processes, in particular of interference control. A total 86 children with dyslexia and 31 normal readers were recruited. Our results revealed that in addition to phonological processing and processing speed, interference control predicts rapid naming in dyslexia, but in contrast to these other two cognitive processes, inhibition is not significantly associated with their reading and spelling skills. After variance in reading and spelling associated with processing speed, interference control and phonological processing was partialled out, naming speed was no longer consistently associated with the reading and spelling skills of children with dyslexia. Finally, dyslexic children differed from normal readers on naming speed, literacy skills, phonological processing and processing speed, but not on inhibition processes. Both theoretical and clinical interpretations of these results are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

Application of tunable diode laser absorption spectroscopy in the detection of oxygen

NASA Astrophysics Data System (ADS)

Zhou, Xin; Jin, Xing

2015-10-01

Most aircrafts is driven by chemic energy which is released in the combustion process. For improving the capability of engine and controlling the running on-time, the processes of fuel physics and chemistry need to be analysis by kinds of high quality sensor. In the research of designing and improving the processes of fuel physics and chemistry, the concentration, temperature and velocity of kinds of gas in the combustor need to be detected and measured. In addition, these engines and research equipments are always in the harsh environment of high temperature, high pressure and high speed. The harsh environment needs the sensor to be high reliability, well repetition, no cross- sensitivity between gases, and the traditional measurement system can't satisfy the metrical requirement well. Tunable diode laser absorption spectroscopy (TDLAS) analytic measurement technology can well satisfy the measurement in the harsh environment, which can support the whole measurement plan and high quality measurement system. Because the TDLAS sensor has the excellence of small bulk, light weight, high reliability and well specifically measurement, the TDLAS measurement technology has wide prospects. Different from most measurements, only a beam of laser can be pass through the measured environment by TDLAS, and the measurement equipment needn't be set in the harsh environment. So, the TDLAS equipment can't be interrupted by the measured equipment. The ability of subsistence in the harsh environment is very valuable, especially in the measurement on the subject of aerospace with environment of high speed, combustion and plasma. This paper focuses on the collecting the articles on the subject of oxygen detection of TDLAS. By analyzing the research and results of the articles, we conclude the central issues, difficulties and results. And we can get some instructive conclusions.

An implicit non-self-report measure of attitudes to speeding: development and validation.

PubMed

Hatfield, Julie; Fernandes, Ralston; Faunce, Gavin; Job, R F Soames

2008-03-01

Speeding is a major contributor to road trauma and attitudes toward speeding are hypothesised to be a key determinant of the behaviour. Attitudinal research is limited by reliance on self-report measures and the attendant possibility of reporting biases. The Implicit Association Test (IAT) aims to measure attitudes without reliance on self-report, by assessing the association between a target-concept and an evaluation, in terms of reaction time for compatible versus non-compatible pairings. The present research aimed to develop and evaluate an IAT to measure attitudes to speeding. Forty-five licensed drivers completed the speed-related IAT, and drove a driving simulator. Participants also completed a questionnaire that assessed self-reported attitudes to speeding, and several variables theoretically related to attitudes, including speeding behaviour. Observed IAT results suggested that attitudes toward speeding are negative, and were generally consistent with results derived from the simulated driving and self-reported behaviours, beliefs, and attitudes. Thus, the speed-related IAT appears to be a valid measure of attitudes toward speeding, which might be used to measure attitudes in road safety research without reliance on self-report.

Physical mechanism of mind changes and tradeoffs among speed, accuracy, and energy cost in brain decision making: Landscape, flux, and path perspectives

NASA Astrophysics Data System (ADS)

Han, Yan; Kun, Zhang; Jin, Wang

2016-07-01

Cognitive behaviors are determined by underlying neural networks. Many brain functions, such as learning and memory, have been successfully described by attractor dynamics. For decision making in the brain, a quantitative description of global attractor landscapes has not yet been completely given. Here, we developed a theoretical framework to quantify the landscape associated with the steady state probability distributions and associated steady state curl flux, measuring the degree of non-equilibrium through the degree of detailed balance breaking for decision making. We quantified the decision-making processes with optimal paths from the undecided attractor states to the decided attractor states, which are identified as basins of attractions, on the landscape. Both landscape and flux determine the kinetic paths and speed. The kinetics and global stability of decision making are explored by quantifying the landscape topography through the barrier heights and the mean first passage time. Our theoretical predictions are in agreement with experimental observations: more errors occur under time pressure. We quantitatively explored two mechanisms of the speed-accuracy tradeoff with speed emphasis and further uncovered the tradeoffs among speed, accuracy, and energy cost. Our results imply that there is an optimal balance among speed, accuracy, and the energy cost in decision making. We uncovered the possible mechanisms of changes of mind and how mind changes improve performance in decision processes. Our landscape approach can help facilitate an understanding of the underlying physical mechanisms of cognitive processes and identify the key factors in the corresponding neural networks. Project supported by the National Natural Science Foundation of China (Grant Nos. 21190040, 91430217, and 11305176).

Decomposing decision components in the Stop-signal task: A model-based approach to individual differences in inhibitory control

PubMed Central

White, Corey N.; Congdon, Eliza; Mumford, Jeanette A.; Karlsgodt, Katherine H.; Sabb, Fred W.; Freimer, Nelson B.; London, Edythe D.; Cannon, Tyrone D.; Bilder, Robert M.; Poldrack, Russell A.

2014-01-01

The Stop-signal task (SST), in which participants must inhibit prepotent responses, has been used to identify neural systems that vary with individual differences in inhibitory control. To explore how these differences relate to other aspects of decision-making, a drift diffusion model of simple decisions was fitted to SST data from Go trials to extract measures of caution, motor execution time, and stimulus processing speed for each of 123 participants. These values were used to probe fMRI data to explore individual differences in neural activation. Faster processing of the Go stimulus correlated with greater activation in the right frontal pole for both Go and Stop trials. On Stop trials stimulus processing speed also correlated with regions implicated in inhibitory control, including the right inferior frontal gyrus, medial frontal gyrus, and basal ganglia. Individual differences in motor execution time correlated with activation of the right parietal cortex. These findings suggest a robust relationship between the speed of stimulus processing and inhibitory processing at the neural level. This model-based approach provides novel insight into the interrelationships among decision components involved in inhibitory control, and raises interesting questions about strategic adjustments in performance and inhibitory deficits associated with psychopathology. PMID:24405185

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

The Predictive Impact of Biological and Sociocultural Factors on Executive Processing: The Role of Age, Education, and Frequency of Reading and Writing Habits.

PubMed

Cotrena, Charles; Branco, Laura D; Cardoso, Caroline O; Wong, Cristina Elizabeth I; Fonseca, Rochele P

2016-01-01

Although the impact of education and age on executive functions (EF) has been widely studied, the influence of daily cognitive stimulation on EF has not been sufficiently investigated. Therefore, the aim of the present study was to evaluate whether the age, education, and frequency of reading and writing habits (FRWH) of healthy adults could predict their performance on measures of inhibition and cognitive flexibility. Inhibition speed, inhibitory control, and set shifting were assessed using speed, accuracy, and discrepancy scores on the Trail-Making Test (TMT) and Hayling Test. Demographic characteristics and the FRWH were assessed using specialized questionnaires. Regression analyses showed that age and the FRWH predicted speed and accuracy on the TMT. The FRWH predicted both speed and accuracy on the Hayling Test, for which speed and accuracy scores were also partly explained by age and education, respectively. Surprisingly, only the FRWH was associated with Hayling Test discrepancy scores, considered one of the purest EF measures. This highlights the importance of regular cognitive stimulation over the number of years of formal education on EF tasks. Further studies are required to investigate the role of the FRWH so as to better comprehend its relationship with EF and general cognition.

Fast tunable blazed MEMS grating for external cavity lasers

NASA Astrophysics Data System (ADS)

Tormen, Maurizio; Niedermann, Philippe; Hoogerwerf, Arno; Shea, Herbert; Stanley, Ross

2017-11-01

Diffractive MEMS are interesting for a wide range of applications, including displays, scanners or switching elements. Their advantages are compactness, potentially high actuation speed and in the ability to deflect light at large angles. We have designed and fabricated deformable diffractive MEMS grating to be used as tuning elements for external cavity lasers. The resulting device is compact, has wide tunability and a high operating speed. The initial design is a planar grating where the beams are free-standing and attached to each other using leaf springs. Actuation is achieved through two electrostatic comb drives at either end of the grating. To prevent deformation of the free-standing grating, the device is 10 μm thick made from a Silicon on Insulator (SOI) wafer in a single mask process. At 100V a periodicity tuning of 3% has been measured. The first resonant mode of the grating is measured at 13.8 kHz, allowing high speed actuation. This combination of wide tunability and high operating speed represents state of the art in the domain of tunable MEMS filters. In order to improve diffraction efficiency and to expand the usable wavelength range, a blazed version of the deformable MEMS grating has been designed. A key issue is maintaining the mechanical properties of the original device while providing optically smooth blazed beams. Using a process based on anisotropic KOH etching, blazed gratings have been obtained and preliminary characterization is promising.

Anterior cingulate cortex surface area relates to behavioral inhibition in adolescents with and without heavy prenatal alcohol exposure

PubMed Central

Migliorini, Robyn; Moore, Eileen M.; Glass, Leila; Infante, M. Alejandra; Tapert, Susan F.; Jones, Kenneth Lyons; Mattson, Sarah N.; Riley, Edward P.

2015-01-01

Prenatal alcohol exposure is associated with behavioral disinhibition, yet the brain structure correlates of this deficit have not been determined with sufficient detail. We examined the hypothesis that the structure of the anterior cingulate cortex (ACC) relates to inhibition performance in youth with histories of heavy prenatal alcohol exposure (AE, n = 32) and non-exposed controls (CON, n = 21). Adolescents (12–17 years) underwent structural magnetic resonance imaging yielding measures of gray matter volume, surface area, and thickness across four ACC subregions. A subset of subjects were administered the NEPSY-II Inhibition subtest. MANCOVA was utilized to test for group differences in ACC and inhibition performance and multiple linear regression was used to probe ACC-inhibition relationships. ACC surface area was significantly smaller in AE, though this effect was primarily driven by reduced right caudal ACC (rcACC). AE also performed significantly worse on inhibition speed but not on inhibition accuracy. Regression analyses with the rcACC revealed a significant group × ACC interaction. A smaller rcACC surface area was associated with slower inhibition completion time for AE but was not significantly associated with inhibition in CON. After accounting for processing speed, smaller rcACC surface area was associated with worse (i.e., slower) inhibition regardless of group. Examining processing speed independently, a decrease in rcACC surface area was associated with faster processing speed for CON but not significantly associated with processing speed in AE. Results support the theory that caudal ACC may monitor reaction time in addition to inhibition and highlight the possibility of delayed ACC neurodevelopment in prenatal alcohol exposure. PMID:26025509

Anterior cingulate cortex surface area relates to behavioral inhibition in adolescents with and without heavy prenatal alcohol exposure.

PubMed

Migliorini, Robyn; Moore, Eileen M; Glass, Leila; Infante, M Alejandra; Tapert, Susan F; Jones, Kenneth Lyons; Mattson, Sarah N; Riley, Edward P

2015-10-01

Prenatal alcohol exposure is associated with behavioral disinhibition, yet the brain structure correlates of this deficit have not been determined with sufficient detail. We examined the hypothesis that the structure of the anterior cingulate cortex (ACC) relates to inhibition performance in youth with histories of heavy prenatal alcohol exposure (AE, n = 32) and non-exposed controls (CON, n = 21). Adolescents (12-17 years) underwent structural magnetic resonance imaging yielding measures of gray matter volume, surface area, and thickness across four ACC subregions. A subset of subjects were administered the NEPSY-II Inhibition subtest. MANCOVA was utilized to test for group differences in ACC and inhibition performance and multiple linear regression was used to probe ACC-inhibition relationships. ACC surface area was significantly smaller in AE, though this effect was primarily driven by reduced right caudal ACC (rcACC). AE also performed significantly worse on inhibition speed but not on inhibition accuracy. Regression analyses with the rcACC revealed a significant group × ACC interaction. A smaller rcACC surface area was associated with slower inhibition completion time for AE but was not significantly associated with inhibition in CON. After accounting for processing speed, smaller rcACC surface area was associated with worse (i.e., slower) inhibition regardless of group. Examining processing speed independently, a decrease in rcACC surface area was associated with faster processing speed for CON but not significantly associated with processing speed in AE. Results support the theory that caudal ACC may monitor reaction time in addition to inhibition and highlight the possibility of delayed ACC neurodevelopment in prenatal alcohol exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

Visual attention in posterior stroke and relations to alexia.

PubMed

Petersen, A; Vangkilde, S; Fabricius, C; Iversen, H K; Delfi, T S; Starrfelt, R

2016-11-01

Impaired visual attention is common following strokes in the territory of the middle cerebral artery, particularly in the right hemisphere, while attentional effects of more posterior lesions are less clear. Commonly, such deficits are investigated in relation to specific syndromes like visual agnosia or pure alexia. The aim of this study was to characterize visual processing speed and apprehension span following posterior cerebral artery (PCA) stroke. In addition, the relationship between these attentional parameters and single word reading is investigated, as previous studies have suggested that reduced visual speed and span may explain pure alexia. Eight patients with unilateral PCA strokes (four left hemisphere, four right hemisphere) were selected on the basis of lesion location, rather than the presence of any visual symptoms. Visual attention was characterized by a whole report paradigm allowing for hemifield-specific measurements of processing speed and apprehension span. All patients showed reductions in visual span contralateral to the lesion site, and four patients showed bilateral reductions in visual span despite unilateral lesions (2L; 2R). Six patients showed selective deficits in visual span, though processing speed was unaffected in the same field (ipsi- or contralesionally). Only patients with right hemifield reductions in visual span were impaired in reading, and this could follow either right or left lateralized stroke and was irrespective of visual field impairments. In conclusion, visual span may be affected bilaterally by unilateral PCA-lesions. Reductions in visual span may also be confined to one hemifield, and may be affected in spite of preserved visual processing speed. Furthermore, reduced span in the right visual field seems to be related to reading impairment in this group, regardless of lesion lateralization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aircraft Speed Instruments

NASA Technical Reports Server (NTRS)

Beij, K Hilding

1933-01-01

This report presents a concise survey of the measurement of air speed and ground speed on board aircraft. Special attention is paid to the pitot-static air-speed meter which is the standard in the United States for airplanes. Air-speed meters of the rotating vane type are also discussed in considerable detail on account of their value as flight test instruments and as service instruments for airships. Methods of ground-speed measurement are treated briefly, with reference to the more important instruments. A bibliography on air-speed measurement concludes the report.

Dynamic calibration and analysis of crack tip propagation in energetic materials using real-time radiography

NASA Astrophysics Data System (ADS)

Butt, Ali

Crack propagation in a solid rocket motor environment is difficult to measure directly. This experimental and analytical study evaluated the viability of real-time radiography for detecting bore regression and propellant crack propagation speed. The scope included the quantitative interpretation of crack tip velocity from simulated radiographic images of a burning, center-perforated grain and actual real-time radiographs taken on a rapid-prototyped model that dynamically produced the surface movements modeled in the simulation. The simplified motor simulation portrayed a bore crack that propagated radially at a speed that was 10 times the burning rate of the bore. Comparing the experimental image interpretation with the calibrated surface inputs, measurement accuracies were quantified. The average measurements of the bore radius were within 3% of the calibrated values with a maximum error of 7%. The crack tip speed could be characterized with image processing algorithms, but not with the dynamic calibration data. The laboratory data revealed that noise in the transmitted X-Ray intensity makes sensing the crack tip propagation using changes in the centerline transmitted intensity level impractical using the algorithms employed.

The useful field of view assessment predicts simulated commercial motor vehicle driving safety.

PubMed

McManus, Benjamin; Heaton, Karen; Vance, David E; Stavrinos, Despina

2016-10-02

The Useful Field of View (UFOV) assessment, a measure of visual speed of processing, has been shown to be a predictive measure of motor vehicle collision (MVC) involvement in an older adult population, but it remains unknown whether UFOV predicts commercial motor vehicle (CMV) driving safety during secondary task engagement. The purpose of this study is to determine whether the UFOV assessment predicts simulated MVCs in long-haul CMV drivers. Fifty licensed CMV drivers (Mage = 39.80, SD = 8.38, 98% male, 56% Caucasian) were administered the 3-subtest version of the UFOV assessment, where lower scores measured in milliseconds indicated better performance. CMV drivers completed 4 simulated drives, each spanning approximately a 22.50-mile distance. Four secondary tasks were presented to participants in a counterbalanced order during the drives: (a) no secondary task, (b) cell phone conversation, (c) text messaging interaction, and (d) e-mailing interaction with an on-board dispatch device. The selective attention subtest significantly predicted simulated MVCs regardless of secondary task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC in the simulated drive. The e-mail interaction secondary task significantly predicted simulated MVCs with a 4.14 times greater risk of an MVC compared to the no secondary task condition. Subtest 3, a measure of visual speed of processing, significantly predicted MVCs in the email interaction task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC during the email interaction task. The UFOV subtest 3 may be a promising measure to identify CMV drivers who may be at risk for MVCs or in need of cognitive training aimed at improving speed of processing. Subtest 3 may also identify CMV drivers who are particularly at risk when engaged in secondary tasks while driving.

High-speed imaging using compressed sensing and wavelength-dependent scattering (Conference Presentation)

NASA Astrophysics Data System (ADS)

Shin, Jaewook; Bosworth, Bryan T.; Foster, Mark A.

2017-02-01

The process of multiple scattering has inherent characteristics that are attractive for high-speed imaging with high spatial resolution and a wide field-of-view. A coherent source passing through a multiple-scattering medium naturally generates speckle patterns with diffraction-limited features over an arbitrarily large field-of-view. In addition, the process of multiple scattering is deterministic allowing a given speckle pattern to be reliably reproduced with identical illumination conditions. Here, by exploiting wavelength dependent multiple scattering and compressed sensing, we develop a high-speed 2D time-stretch microscope. Highly chirped pulses from a 90-MHz mode-locked laser are sent through a 2D grating and a ground-glass diffuser to produce 2D speckle patterns that rapidly evolve with the instantaneous frequency of the chirped pulse. To image a scene, we first characterize the high-speed evolution of the generated speckle patterns. Subsequently we project the patterns onto the microscopic region of interest and collect the total light from the scene using a single high-speed photodetector. Thus the wavelength dependent speckle patterns serve as high-speed pseudorandom structured illumination of the scene. An image sequence is then recovered using the time-dependent signal received by the photodetector, the known speckle pattern evolution, and compressed sensing algorithms. Notably, the use of compressed sensing allows for reconstruction of a time-dependent scene using a highly sub-Nyquist number of measurements, which both increases the speed of the imager and reduces the amount of data that must be collected and stored. We will discuss our experimental demonstration of this approach and the theoretical limits on imaging speed.

Speed of Language Comprehension at 18 Months Old Predicts School-Relevant Outcomes at 54 Months Old in Children Born Preterm.

PubMed

Marchman, Virginia A; Loi, Elizabeth C; Adams, Katherine A; Ashland, Melanie; Fernald, Anne; Feldman, Heidi M

2018-04-01

Identifying which preterm (PT) children are at increased risk of language and learning differences increases opportunities for participation in interventions that improve outcomes. Speed in spoken language comprehension at early stages of language development requires information processing skills that may form the foundation for later language and school-relevant skills. In children born full-term, speed of comprehending words in an eye-tracking task at 2 years old predicted language and nonverbal cognition at 8 years old. Here, we explore the extent to which speed of language comprehension at 1.5 years old predicts both verbal and nonverbal outcomes at 4.5 years old in children born PT. Participants were children born PT (n = 47; ≤32 weeks gestation). Children were tested in the "looking-while-listening" task at 18 months old, adjusted for prematurity, to generate a measure of speed of language comprehension. Parent report and direct assessments of language were also administered. Children were later retested on a test battery of school-relevant skills at 4.5 years old. Speed of language comprehension at 18 months old predicted significant unique variance (12%-31%) in receptive vocabulary, global language abilities, and nonverbal intelligence quotient (IQ) at 4.5 years, controlling for socioeconomic status, gestational age, and medical complications of PT birth. Speed of language comprehension remained uniquely predictive (5%-12%) when also controlling for children's language skills at 18 months old. Individual differences in speed of spoken language comprehension may serve as a marker for neuropsychological processes that are critical for the development of school-relevant linguistic skills and nonverbal IQ in children born PT.

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

PubMed

Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Nozawa, Takayuki; Kambara, Toshimune; Sekiguchi, Atsushi; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Nouchi, Haruka; Kawashima, Ryuta

2013-01-01

Do brain training games work? The beneficial effects of brain training games are expected to transfer to other cognitive functions. Yet in all honesty, beneficial transfer effects of the commercial brain training games in young adults have little scientific basis. Here we investigated the impact of the brain training game (Brain Age) on a wide range of cognitive functions in young adults. We conducted a double-blind (de facto masking) randomized controlled trial using a popular brain training game (Brain Age) and a popular puzzle game (Tetris). Thirty-two volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into eight categories (fluid intelligence, executive function, working memory, short-term memory, attention, processing speed, visual ability, and reading ability). Our results showed that commercial brain training game improves executive functions, working memory, and processing speed in young adults. Moreover, the popular puzzle game can engender improvement attention and visuo-spatial ability compared to playing the brain training game. The present study showed the scientific evidence which the brain training game had the beneficial effects on cognitive functions (executive functions, working memory and processing speed) in the healthy young adults. Our results do not indicate that everyone should play brain training games. However, the commercial brain training game might be a simple and convenient means to improve some cognitive functions. We believe that our findings are highly relevant to applications in educational and clinical fields. UMIN Clinical Trial Registry 000005618.

The impact of social activities, social networks, social support and social relationships on the cognitive functioning of healthy older adults: a systematic review.

PubMed

Kelly, Michelle E; Duff, Hollie; Kelly, Sara; McHugh Power, Joanna E; Brennan, Sabina; Lawlor, Brian A; Loughrey, David G

2017-12-19

Social relationships, which are contingent on access to social networks, promote engagement in social activities and provide access to social support. These social factors have been shown to positively impact health outcomes. In the current systematic review, we offer a comprehensive overview of the impact of social activities, social networks and social support on the cognitive functioning of healthy older adults (50+) and examine the differential effects of aspects of social relationships on various cognitive domains. We followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, and collated data from randomised controlled trials (RCTs), genetic and observational studies. Independent variables of interest included subjective measures of social activities, social networks, and social support, and composite measures of social relationships (CMSR). The primary outcome of interest was cognitive function divided into domains of episodic memory, semantic memory, overall memory ability, working memory, verbal fluency, reasoning, attention, processing speed, visuospatial abilities, overall executive functioning and global cognition. Thirty-nine studies were included in the review; three RCTs, 34 observational studies, and two genetic studies. Evidence suggests a relationship between (1) social activity and global cognition and overall executive functioning, working memory, visuospatial abilities and processing speed but not episodic memory, verbal fluency, reasoning or attention; (2) social networks and global cognition but not episodic memory, attention or processing speed; (3) social support and global cognition and episodic memory but not attention or processing speed; and (4) CMSR and episodic memory and verbal fluency but not global cognition. The results support prior conclusions that there is an association between social relationships and cognitive function but the exact nature of this association remains unclear. Implications of the findings are discussed and suggestions for future research provided. PROSPERO 2012: CRD42012003248 .

Brain Training Game Boosts Executive Functions, Working Memory and Processing Speed in the Young Adults: A Randomized Controlled Trial

PubMed Central

Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Nozawa, Takayuki; Kambara, Toshimune; Sekiguchi, Atsushi; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Nouchi, Haruka; Kawashima, Ryuta

2013-01-01

Background Do brain training games work? The beneficial effects of brain training games are expected to transfer to other cognitive functions. Yet in all honesty, beneficial transfer effects of the commercial brain training games in young adults have little scientific basis. Here we investigated the impact of the brain training game (Brain Age) on a wide range of cognitive functions in young adults. Methods We conducted a double-blind (de facto masking) randomized controlled trial using a popular brain training game (Brain Age) and a popular puzzle game (Tetris). Thirty-two volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into eight categories (fluid intelligence, executive function, working memory, short-term memory, attention, processing speed, visual ability, and reading ability). Results and Discussion Our results showed that commercial brain training game improves executive functions, working memory, and processing speed in young adults. Moreover, the popular puzzle game can engender improvement attention and visuo-spatial ability compared to playing the brain training game. The present study showed the scientific evidence which the brain training game had the beneficial effects on cognitive functions (executive functions, working memory and processing speed) in the healthy young adults. Conclusions Our results do not indicate that everyone should play brain training games. However, the commercial brain training game might be a simple and convenient means to improve some cognitive functions. We believe that our findings are highly relevant to applications in educational and clinical fields. Trial Registration UMIN Clinical Trial Registry 000005618. PMID:23405164

Full Flight Envelope Direct Thrust Measurement on a Supersonic Aircraft

NASA Technical Reports Server (NTRS)

Conners, Timothy R.; Sims, Robert L.

1998-01-01

Direct thrust measurement using strain gages offers advantages over analytically-based thrust calculation methods. For flight test applications, the direct measurement method typically uses a simpler sensor arrangement and minimal data processing compared to analytical techniques, which normally require costly engine modeling and multisensor arrangements throughout the engine. Conversely, direct thrust measurement has historically produced less than desirable accuracy because of difficulty in mounting and calibrating the strain gages and the inability to account for secondary forces that influence the thrust reading at the engine mounts. Consequently, the strain-gage technique has normally been used for simple engine arrangements and primarily in the subsonic speed range. This paper presents the results of a strain gage-based direct thrust-measurement technique developed by the NASA Dryden Flight Research Center and successfully applied to the full flight envelope of an F-15 aircraft powered by two F100-PW-229 turbofan engines. Measurements have been obtained at quasi-steady-state operating conditions at maximum non-augmented and maximum augmented power throughout the altitude range of the vehicle and to a maximum speed of Mach 2.0 and are compared against results from two analytically-based thrust calculation methods. The strain-gage installation and calibration processes are also described.

Impact of neurocognition on social and role functioning in individuals at clinical high risk for psychosis.

PubMed

Carrión, Ricardo E; Goldberg, Terry E; McLaughlin, Danielle; Auther, Andrea M; Correll, Christoph U; Cornblatt, Barbara A

2011-08-01

Cognitive deficits have been well documented in schizophrenia and have been shown to impair quality of life and to compromise everyday functioning. Recent studies of adolescents and young adults at high risk for developing psychosis show that neurocognitive impairments are detectable before the onset of psychotic symptoms. However, it remains unclear how cognitive impairments affect functioning before the onset of psychosis. The authors assessed cognitive impairment in adolescents at clinical high risk for psychosis and examined its impact on social and role functioning. A sample of 127 treatment-seeking patients at clinical high risk for psychosis and a group of 80 healthy comparison subjects were identified and recruited for research in the Recognition and Prevention Program. At baseline, participants were assessed with a comprehensive neurocognitive battery as well as measures of social and role functioning. Relative to healthy comparison subjects, clinical high-risk patients showed significant impairments in the domains of processing speed, verbal memory, executive function, working memory, visuospatial processing, motor speed, sustained attention, and language. Clinical high-risk patients also displayed impaired social and role functioning at baseline. Among patients with attenuated positive symptoms, processing speed was related to social and role functioning at baseline. These findings demonstrate that cognitive and functional impairments are detectable in patients at clinical high risk for psychosis before the onset of psychotic illness and that processing speed appears to be an important cognitive predictor of poor functioning.

Cognitive status in patients with multiple sclerosis in Lanzarote.

PubMed

Pérez-Martín, María Yaiza; Eguia-Del Río, Pablo; González-Platas, Montserrat; Jiménez-Sosa, Alejandro

2016-01-01

Cognitive impairment is a common feature in multiple sclerosis affecting ~43%-72% of patients, which involves cognitive functions such as memory, processing speed, attention, and executive function. The aim of this study was to describe the extent and pattern of the involvement of cognitive impairment and psychological status in all patients with multiple sclerosis on a small Spanish island. In all, 70 patients and 56 healthy controls were included in the study between February 2013 and May 2013. All participants were assessed using the Brief Repeatable Battery of Neuropsychological Test. The patients also completed instruments to evaluate the presence of fatigue, perceived cognitive dysfunction, and symptoms of anxiety and depression. All procedures were performed in a single session. Cognitive impairment, defined as a score <1.5 standard deviation on two subtests of the battery, was present in 35% of the participants. The most frequently affected domain was working memory, followed by verbal memory and processing speed. Disease duration showed a moderate correlation with visuospatial memory and processing speed. The Expanded Disability Status Scale score correlated with verbal and processing speed. Verbal memory was correlated with depression symptoms and fatigue. Cognitive impairment was present in 35% of the study population. The most affected domains were working memory and verbal memory. Working memory and verbal fluency deficit are independent factors of disease evolution. Cognitive decline is related to clinical variables and psychological measures such as fatigue or depression but not to anxiety.

Cognitive status in patients with multiple sclerosis in Lanzarote

PubMed Central

Pérez-Martín, María Yaiza; Eguia-del Río, Pablo; González-Platas, Montserrat; Jiménez-Sosa, Alejandro

2016-01-01

Objectives Cognitive impairment is a common feature in multiple sclerosis affecting ~43%–72% of patients, which involves cognitive functions such as memory, processing speed, attention, and executive function. The aim of this study was to describe the extent and pattern of the involvement of cognitive impairment and psychological status in all patients with multiple sclerosis on a small Spanish island. Patients and methods In all, 70 patients and 56 healthy controls were included in the study between February 2013 and May 2013. All participants were assessed using the Brief Repeatable Battery of Neuropsychological Test. The patients also completed instruments to evaluate the presence of fatigue, perceived cognitive dysfunction, and symptoms of anxiety and depression. All procedures were performed in a single session. Results Cognitive impairment, defined as a score <1.5 standard deviation on two subtests of the battery, was present in 35% of the participants. The most frequently affected domain was working memory, followed by verbal memory and processing speed. Disease duration showed a moderate correlation with visuospatial memory and processing speed. The Expanded Disability Status Scale score correlated with verbal and processing speed. Verbal memory was correlated with depression symptoms and fatigue. Conclusion Cognitive impairment was present in 35% of the study population. The most affected domains were working memory and verbal memory. Working memory and verbal fluency deficit are independent factors of disease evolution. Cognitive decline is related to clinical variables and psychological measures such as fatigue or depression but not to anxiety. PMID:27418825

Impact of Neurocognition on Social and Role Functioning in Individuals at Clinical High Risk for Psychosis

PubMed Central

Carrión, Ricardo E.; Goldberg, Terry E.; McLaughlin, Danielle; Auther, Andrea M.; Correll, Christoph U.; Cornblatt, Barbara A.

2011-01-01

Objective Cognitive deficits have been well documented in schizophrenia and have been shown to impair quality of life and to compromise everyday functioning. Recent studies of adolescents and young adults at high risk for developing psychosis show that neurocognitive impairments are detectable before the onset of psychotic symptoms. However, it remains unclear how cognitive impairments affect functioning before the onset of psychosis. The authors assessed cognitive impairment in adolescents at clinical high risk for psychosis and examined its impact on social and role functioning. Method A sample of 127 treatment-seeking patients at clinical high risk for psychosis and a group of 80 healthy comparison subjects were identified and recruited for research in the Recognition and Prevention Program. At baseline, participants were assessed with a comprehensive neurocognitive battery as well as measures of social and role functioning. Results Relative to healthy comparison subjects, clinical high-risk patients showed significant impairments in the domains of processing speed, verbal memory, executive function, working memory, visuospatial processing, motor speed, sustained attention, and language. Clinical high-risk patients also displayed impaired social and role functioning at baseline. Among patients with attenuated positive symptoms, processing speed was related to social and role functioning at baseline. Conclusions These findings demonstrate that cognitive and functional impairments are detectable in patients at clinical high risk for psychosis before the onset of psychotic illness and that processing speed appears to be an important cognitive predictor of poor functioning. PMID:21536691

Information processing speed in obstructive sleep apnea syndrome: a review.

PubMed

Kilpinen, R; Saunamäki, T; Jehkonen, M

2014-04-01

To provide a comprehensive review of studies on information processing speed in patients with obstructive sleep apnea syndrome (OSAS) as compared to healthy controls and normative data, and to determine whether continuous positive airway pressure (CPAP) treatment improves information processing speed. A systematic review was performed on studies drawn from Medline and PsycINFO (January 1990-December 2011) and identified from lists of references in these studies. After inclusion criteria, 159 articles were left for abstract review, and after exclusion criteria 44 articles were fully reviewed. The number of patients in the studies reviewed ranged from 10 to 157 and the study samples consisted mainly of men. Half of the studies reported that patients with OSAS showed reduced information processing speed when compared to healthy controls. Reduced information processing speed was seen more often (75%) when compared to norm-referenced data. Psychomotor speed seemed to be particularly liable to change. CPAP treatment improved processing speed, but the improvement was marginal when compared to placebo or conservative treatment. Patients with OSAS are affected by reduced information processing speed, which may persist despite CPAP treatment. Information processing is usually assessed as part of other cognitive functioning, not as a cognitive domain per se. However, it is important to take account of information processing speed when assessing other aspects of cognitive functioning. This will make it possible to determine whether cognitive decline in patients with OSAS is based on lower-level or higher-level cognitive processes or both. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Frequency domain laser velocimeter signal processor

NASA Technical Reports Server (NTRS)

Meyers, James F.; Murphy, R. Jay

1991-01-01

A new scheme for processing signals from laser velocimeter systems is described. The technique utilizes the capabilities of advanced digital electronics to yield a signal processor capable of operating in the frequency domain maximizing the information obtainable from each signal burst. This allows a sophisticated approach to signal detection and processing, with a more accurate measurement of the chirp frequency resulting in an eight-fold increase in measurable signals over the present high-speed burst counter technology. Further, the required signal-to-noise ratio is reduced by a factor of 32, allowing measurements within boundary layers of wind tunnel models. Measurement accuracy is also increased up to a factor of five.

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

Optimization of rotational speed for growing BaFe12O19 thin films using spin coating

NASA Astrophysics Data System (ADS)

Budiawanti, S.; Soegijono, B.; Mudzakir, I.; Suharno, Fadillah, L.

2017-07-01

Barium ferrite (BaFe12O19, BaM) thin films were fabricated by the spin coating of precursors obtained by using a sol-gel method. The effects of the rotational speed on the spin-coating process for growing a BaM thin film were investigated in this study. Coated films were heat-deposited at different rotational speeds ranging from 2000 to 4000 rpm, while the number of layers was set to nine. Further, the effect of the number of layers on the growth of BaM thin films was discussed. For this purpose, we take the layers number 1 to 12 and take the constant rotational speed of 3000 rpm. All the film were characterized using X-Ray diffraction, Scanning Electron microscope, and Energy-dispersive X-Ray spectroscopy and Vibrating Sample Magnetometer. It was found that by increasing the rotational speed the amount of material deposited on the Si substrate decreased. The measured grain size of the BaM thin film was nearly similar for three three different rotational speeds. However, the grain size was found to increase the number of layers.

Application of High Speed Digital Image Correlation in Rocket Engine Hot Fire Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.; Schmidt, Tim

2016-01-01

Hot fire testing of rocket engine components and rocket engine systems is a critical aspect of the development process to understand performance, reliability and system interactions. Ground testing provides the opportunity for highly instrumented development testing to validate analytical model predictions and determine necessary design changes and process improvements. To properly obtain discrete measurements for model validation, instrumentation must survive in the highly dynamic and extreme temperature application of hot fire testing. Digital Image Correlation has been investigated and being evaluated as a technique to augment traditional instrumentation during component and engine testing providing further data for additional performance improvements and cost savings. The feasibility of digital image correlation techniques were demonstrated in subscale and full scale hotfire testing. This incorporated a pair of high speed cameras to measure three-dimensional, real-time displacements and strains installed and operated under the extreme environments present on the test stand. The development process, setup and calibrations, data collection, hotfire test data collection and post-test analysis and results are presented in this paper.

Faster on Easy Items, More Accurate on Difficult Ones: Cognitive Ability and Performance on a Task of Varying Difficulty

ERIC Educational Resources Information Center

Dodonova, Yulia A.; Dodonov, Yury S.

2013-01-01

Using more complex items than those commonly employed within the information-processing approach, but still easier than those used in intelligence tests, this study analyzed how the association between processing speed and accuracy level changes as the difficulty of the items increases. The study involved measuring cognitive ability using Raven's…

Hippocampal Structure and Human Cognition: Key Role of Spatial Processing and Evidence Supporting the Efficiency Hypothesis in Females

ERIC Educational Resources Information Center

Colom, Roberto; Stein, Jason L.; Rajagopalan, Priya; Martinez, Kenia; Hermel, David; Wang, Yalin; Alvarez-Linera, Juan; Burgaleta, Miguel; Quiroga, Ma. Angeles; Shih, Pei Chun; Thompson, Paul M.

2013-01-01

Here we apply a method for automated segmentation of the hippocampus in 3D high-resolution structural brain MRI scans. One hundred and four healthy young adults completed twenty one tasks measuring abstract, verbal, and spatial intelligence, along with working memory, executive control, attention, and processing speed. After permutation tests…

Visual function and cognitive speed of processing mediate age-related decline in memory span and fluid intelligence

PubMed Central

Clay, Olivio J.; Edwards, Jerri D.; Ross, Lesley A.; Okonkwo, Ozioma; Wadley, Virginia G.; Roth, David L.; Ball, Karlene K.

2010-01-01

Objectives: To evaluate the relationship between sensory and cognitive decline, particularly with respect to speed of processing, memory span, and fluid intelligence. Additionally, the common cause, sensory degradation and speed of processing hypotheses were compared. Methods: Structural equation modeling was used to investigate the complex relationships among age-related decrements in these areas. Results: Cross-sectional data analyses included 842 older adult participants (M = 73 years). After accounting for age-related declines in vision and processing speed, the direct associations between age and memory span and between age and fluid intelligence were nonsignificant. Older age was associated with visual decline, which was associated with slower speed of processing, which in turn was associated with greater cognitive deficits. Discussion: The findings support both the sensory degradation and speed of processing accounts of age-related cognitive decline. Further, the findings highlight positive aspects of normal cognitive aging in that older age may not be associated with a loss of fluid intelligence if visual sensory functioning and processing speed can be maintained. PMID:19436063

Driver behavior and accident frequency in school zones: Assessing the impact of sign saturation.

PubMed

Strawderman, Lesley; Rahman, Md Mahmudur; Huang, Yunchen; Nandi, Apurba

2015-09-01

Based on the models of human information processing, if a driver observes too many of the same signs, he or she may no longer pay attention to those signs. In the case of school zones, this expected effect may lead to non-compliance to posted speeds, negatively impacting safety around nearby schools. This study aims to investigate the effect of the number of nearby school zones on driver behavior (vehicle speed and compliance) and accident frequency. As a measure of the density of school zones, this study introduced and defined a new term sign saturation and presented a methodology to calculate sign saturation for school zones. Results found a significant effect of sign saturation on vehicle speed, compliance, and accident frequency. This study also examined the speeding behavior in school zones for different time of the day and day of the week. Results found that speeding was more prevalent in the early mornings and during the weekends. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Cortisol Awakening Response and Cognition across the Adult Lifespan

PubMed Central

Ennis, Gilda E.; Moffat, Scott D.; Hertzog, Christopher

2016-01-01

Although the hippocampus is thought to play a central role in the regulation of the cortisol awakening response (CAR), results from past studies examining the relationship between the CAR and hippocampally-mediated memory and cognition have been mixed. Inconsistent findings may be due to the use of cortisol samples collected on only 1 to 2 days since reduced sampling can permit unstable situational factors to bias results. We used cortisol assessments from 10 consecutive days to test the relationship of the CAR to episodic memory, working memory, and processing speed in a sample of healthy young, middle-aged, and older adults (age range: 23 – 79 years; N = 56). We tested if the relationship between the CAR and cognition would depend upon age and also tested if other cortisol measures, specifically waking cortisol, diurnal cortisol output (i.e., area under the curve) and diurnal cortisol slope (linear and quadratic), would be related to cognition. We found that a more positive CAR slope was related to better episodic memory and that this relationship did not depend upon age. The CAR was not significantly related to working memory. The relationship of the CAR to processing speed was not significant when using a CAR measure that corrected for non-compliant cortisol sampling. We also found that higher waking cortisol was significantly related to better working memory, but not episodic memory or processing speed. Neither diurnal cortisol output nor diurnal linear cortisol slope was significantly related to cognitive functioning. Future work should investigate the mechanisms underpinning the relationship of the cortisol awakening process to cognitive functioning. PMID:27105036

Development of a miniaturized optical viscosity sensor with an optical surface tracking system

NASA Astrophysics Data System (ADS)

Abe, H.; Nagamachi, R.; Taguchi, Y.; Nagasaka, Y.

2010-02-01

A new viscosity sensor enabling non-contact measurement at high speed, with less sample volume and high stability is required in a broad field. For example, in the industrial field, process control by real time monitoring of viscosity can enhance the quality of coating films and the process yield such as conductive films and optical films. Therefore, we have developed a new miniaturized optical viscosity sensor, namely MOVS (Miniaturized Optical Viscosity Sensor), based on a laser-induced capillary wave (LiCW) method which can meet the requirements above. In the MOVS, viscosity is estimated by observing the damping oscillation of LiCW, which is generated by an interference of two excitation laser beams on a liquid surface. By irradiating a probing laser on LiCW, a first order diffracted beam containing information of sample viscosity, is generated. The intensity of the reflected beam is utilized to control the distance between liquid-level and the sensor. The newly integrated optical surface tracking system makes possible the stable viscosity measurement in the presence of disturbance such as evaporation and external vibration. MOVS consists of five U-grooves fabricated by MEMS (Micro Electro Mechanical Systems) process to possess the optical fibers (photonic crystal fibers and fusion-spliced lensed fibers). In this study, by integrating the optical surface tracking system on the chip, nanosecond order damping oscillation of LiCW is successfully observed in the presence of external forced vibration, high speed evaporation (speed of 1 micrometer per second) and drying process of a liquid film (thickness of hundreds micrometer order).

Analysis of the regimes in the scanner-based laser hardening process

NASA Astrophysics Data System (ADS)

Martínez, S.; Lamikiz, A.; Ukar, E.; Calleja, A.; Arrizubieta, J. A.; Lopez de Lacalle, L. N.

2017-03-01

Laser hardening is becoming a consolidated process in different industrial sectors such as the automotive industry or in the die and mold industry. The key to ensure the success in this process is to control the surface temperature and the hardened layer thickness. Furthermore, the development of reliable scanners, based on moving optics for guiding high power lasers at extremely fast speeds allows the rapid motion of laser spots, resulting on tailored shapes of swept areas by the laser. If a scanner is used to sweep a determined area, the laser energy density distribution can be adapted by varying parameters such us the scanning speed or laser power inside this area. Despite its advantages in terms of versatility, the use of scanners for the laser hardening process has not yet been introduced in the thermal hardening industry because of the difficulty of the temperature control and possible non-homogeneous hardness thickness layers. In the present work the laser hardening process with scanning optics applied to AISI 1045 steel has been studied, with special emphasis on the influence of the scanning speed and the results derived from its variation, the evolution of the hardened layer thickness and different strategies for the control of the process temperature. For this purpose, the hardened material has been studied by measuring microhardness at different points and the shape of the hardened layer has also been evaluated. All tests have been performed using an experimental setup designed to keep a nominal temperature value using a closed-loop control. The tests results show two different regimes depending on the scanning speed and feed rate values. The experimental results conclusions have been validated by means of thermal simulations at different conditions.

Inhibition in task switching: The reliability of the n - 2 repetition cost.

PubMed

Kowalczyk, Agnieszka W; Grange, James A

2017-12-01

The n - 2 repetition cost seen in task switching is the effect of slower response times performing a recently completed task (e.g. an ABA sequence) compared to performing a task that was not recently completed (e.g. a CBA sequence). This cost is thought to reflect cognitive inhibition of task representations and as such, the n - 2 repetition cost has begun to be used as an assessment of individual differences in inhibitory control; however, the reliability of this measure has not been investigated in a systematic manner. The current study addressed this important issue. Seventy-two participants performed three task switching paradigms; participants were also assessed on rumination traits and processing speed-measures of individual differences potentially modulating the n - 2 repetition cost. We found significant n - 2 repetition costs for each paradigm. However, split-half reliability tests revealed that this cost was not reliable at the individual-difference level. Neither rumination tendencies nor processing speed predicted this cost. We conclude that the n - 2 repetition cost is not reliable as a measure of individual differences in inhibitory control.

Force characteristics in continuous path controlled crankpin grinding

NASA Astrophysics Data System (ADS)

Zhang, Manchao; Yao, Zhenqiang

2015-03-01

Recent research on the grinding force involved in cylindrical plunge grinding has focused mainly on steady-state conditions. Unlike in conventional external cylindrical plunge grinding, the conditions between the grinding wheel and the crankpin change periodically in path controlled grinding because of the eccentricity of the crankpin and the constant rotational speed of the crankshaft. The objective of this study is to investigate the effects of various grinding conditions on the characteristics of the grinding force during continuous path controlled grinding. Path controlled plunge grinding is conducted at a constant rotational speed using a cubic boron nitride (CBN) wheel. The grinding force is determined by measuring the torque. The experimental results show that the force and torque vary sinusoidally during dry grinding and load grinding. The variations in the results reveal that the resultant grinding force and torque decrease with higher grinding speeds and increase with higher peripheral speeds of the pin and higher grinding depths. In path controlled grinding, unlike in conventional external cylindrical plunge grinding, the axial grinding force cannot be disregarded. The speeds and speed ratios of the workpiece and wheel are also analyzed, and the analysis results show that up-grinding and down-grinding occur during the grinding process. This paper proposes a method for describing the force behavior under varied process conditions during continuous path controlled grinding, which provides a beneficial reference for describing the material removal mechanism and for optimizing continuous controlled crankpin grinding.

Match-to-match variation in physical activity and technical skill measures in professional Australian Football.

PubMed

Kempton, Thomas; Sullivan, Courtney; Bilsborough, Johann C; Cordy, Justin; Coutts, Aaron J

2015-01-01

To determine the match-to-match variability in physical activity and technical performance measures in Australian Football, and examine the influence of playing position, time of season, and different seasons on these measures of variability. Longitudinal observational study. Global positioning system, accelerometer and technical performance measures (total kicks, handballs, possessions and Champion Data rank) were collected from 33 players competing in the Australian Football League over 31 matches during 2011-2012 (N=511 observations). The global positioning system data were categorised into total distance, mean speed (mmin(-1)), high-speed running (>14.4 kmh(-1)), very high-speed running (>19.9 kmh(-1)), and sprint (>23.0 kmh(-1)) distance while player load was collected from the accelerometer. The data were log transformed to provide coefficient of variation and the between subject standard deviation (expressed as percentages). Match-to-match variability was increased for higher speed activities (high-speed running, very high-speed running, sprint distance, coefficient of variation %: 13.3-28.6%) compared to global measures (speed, total distance, player load, coefficient of variation %: 5.3-9.2%). The between-match variability was relativity stable for all measures between and within AFL seasons, with only few differences between positions. Higher speed activities (high-speed running, very high-speed running, sprint distance), but excluding mean speed, total distance and player load, were all higher in the final third phase of the season compared to the start of the season. While global measures of physical performance are relatively stable, higher-speed activities and technical measures exhibit a large degree of between-match variability in Australian Football. However, these measures remain relatively stable between positions, and within and between Australian Football League seasons. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

A laser-induced heat flux technique for convective heat transfer measurements in high speed flows

NASA Technical Reports Server (NTRS)

Porro, A. R.; Keith, T. G., Jr.; Hingst, W. R.

1991-01-01

A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to the heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the local surface convective heat transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimentally determined convective heat transfer coefficients were generally higher than the theoretical predictions for flat plate laminar boundary layers. However, the results indicate that this nonintrusive optical measurement technique has the potential to measure surface convective heat transfer coefficients in high speed flow fields.

A laser-induced heat flux technique for convective heat transfer measurements in high speed flows

NASA Technical Reports Server (NTRS)

Porro, A. R.; Keith, T. G., Jr.; Hingst, W. R.

1991-01-01

A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to the heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the local surface convective heat transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimentally determined convective heat transfer coefficients were generally higher than the theoretical predictions for flat plate laminar boundary layers. However, the results indicate that this nonintrusive optical measurement technique has the potential to measure surface convective heat transfer coefficients in high-speed flowfields.

An optical backscatter probe for time resolved droplet measurements in turbomachines

NASA Astrophysics Data System (ADS)

Bosdas, Ilias; Mansour, Michel; Kalfas, Anestis I.; Abhari, Reza S.

2016-01-01

The presence of particles in the flow path of turbomachines can result in undesirable engine operation. In order to improve the efficiency of turbomachines and guarantee their safe operation, the flow mechanisms that govern the particles’ need to be studied and associated with the main aerodynamic flow field. This paper describes a newly developed optical backscatter probe for droplet diameter and speed measurements in turbomachines. The miniature probe has a tip diameter of 5 mm and is capable of resolving droplets from 40 to 110 μm in diameter that travel up to 200 m s-1. The calibration of the novel probe is performed with a droplet generator capable of producing monodispersed water droplets. In addition, the probe is calibrated for droplet speed measurements in the same calibration facility. The paper conducts a detailed uncertainty analysis and describes the post processing code. In the final part of this paper the probe is used in an axial turbine with an installed spray generator to perform droplet measurements under two different operating conditions. Measurements have shown that the part load condition results in larger droplet diameters and higher relative droplet speeds. As a consequence higher erosion rates at the rotor leading edge suction side will occur when operating at part load condition.

Extension of the Contingency Naming Test to adult assessment: psychometric analysis in a college student sample.

PubMed

Riddle, Tara; Suhr, Julie

2012-01-01

The Contingency Naming Test (CNT; Taylor, Albo, Phebus, Sachs, & Bierl, 1987) was initially designed to assess aspects of executive functioning, such as processing speed and response inhibition, in children. The measure has shown initial utility in identifying differences in executive function among child clinical groups; however, there is an absence of adequate psychometric data for use with adults. The current study expanded psychometric data upward for use with a college student sample and explored the measure's test-retest reliability and factor structure. Performance in the adult sample showed continued improvement above child norms, consistent with theories of executive function development. Exploratory factor analysis showed that the CNT is most closely related to measures of processing speed, as well as elements of response inhibition within the latter trials. Overall, results from the current study provide added support for the utility of the CNT as a measure of executive functioning in young adults. However, more research is needed to determine patterns of performance among adult clinical groups, as well as to better understand how performance patterns may change in a broader age range, including middle and older adulthood.

Impact of one HF-rTMS session on fine motor function in right-handed healthy female subjects: a comparison of stimulation over the left versus the right dorsolateral prefrontal cortex.

PubMed

Baeken, C; Schrijvers, D L; Sabbe, B G C; Vanderhasselt, M A; De Raedt, R

2012-01-01

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool to investigate neural conduction in motor processes. Most rTMS research has been conducted by targeting the primary motor cortex. Several studies have also found increased psychomotor speed after rTMS of the dorsolateral prefrontal cortex (DLPFC). However, these studies were mainly performed in psychiatric patients, only targeting the left DLPFC, and often without sham control. Moreover, psychomotor speed is mostly measured based on tasks that also require higher executive functions. Here, we examined the lateralized effect of one sham-controlled high-frequency rTMS session applied to the left or right DLPFC on fine motor function in 36 healthy right-handed females, using the Fitts' paradigm. We found a significant improvement in psychomotor speed only after actively stimulating the right DLPFC. Our results support the assumption of a right prefrontal neural network implicated in visuomotor behavior and performance processes, and that the improvement in psychomotor speed is not a secondary effect of decreased mood. Copyright © 2012 S. Karger AG, Basel.

Optimization of gold ore Sumbawa separation using gravity method: Shaking table

NASA Astrophysics Data System (ADS)

Ferdana, Achmad Dhaefi; Petrus, Himawan Tri Bayu Murti; Bendiyasa, I. Made; Prijambada, Irfan Dwidya; Hamada, Fumio; Sachiko, Takahi

2018-04-01

Most of artisanal small gold mining in Indonesia has been using amalgamation method, which caused negative impact to the environment around ore processing area due to the usage of mercury. One of the more environmental-friendly method for gold processing is gravity method. Shaking table is one of separation equipment of gravity method used to increase concentrate based on difference of specific gravity. The optimum concentration result is influenced by several variables, such as rotational speed shaking, particle size and deck slope. In this research, the range of rotational speed shaking was between 100 rpm and 200 rpm, the particle size was between -100 + 200 mesh and -200 + 300 mesh and deck slope was between 3° and 7°. Gold concentration in concentrate was measured by EDX. The result shows that the optimum condition is obtained at a shaking speed of 200 rpm, with a slope of 7° and particle size of -100 + 200 mesh.

Parallel processing and expert systems

NASA Technical Reports Server (NTRS)

Yan, Jerry C.; Lau, Sonie

1991-01-01

Whether it be monitoring the thermal subsystem of Space Station Freedom, or controlling the navigation of the autonomous rover on Mars, NASA missions in the 90's cannot enjoy an increased level of autonomy without the efficient use of expert systems. Merely increasing the computational speed of uniprocessors may not be able to guarantee that real time demands are met for large expert systems. Speed-up via parallel processing must be pursued alongside the optimization of sequential implementations. Prototypes of parallel expert systems have been built at universities and industrial labs in the U.S. and Japan. The state-of-the-art research in progress related to parallel execution of expert systems was surveyed. The survey is divided into three major sections: (1) multiprocessors for parallel expert systems; (2) parallel languages for symbolic computations; and (3) measurements of parallelism of expert system. Results to date indicate that the parallelism achieved for these systems is small. In order to obtain greater speed-ups, data parallelism and application parallelism must be exploited.

Effects of information processing speed on learning, memory, and executive functioning in people living with HIV/AIDS.

PubMed

Fellows, Robert P; Byrd, Desiree A; Morgello, Susan

2014-01-01

It is unclear whether or to what degree literacy, aging, and other neurologic abnormalities relate to cognitive deficits among people living with HIV/AIDS in the combined antiretroviral therapy (CART) era. The primary aim of this study was to simultaneously examine the association of age, HIV-associated motor abnormalities, major depressive disorder, and reading level with information processing speed, learning, memory, and executive functions, and to determine whether processing speed mediated any of the relationships between cognitive and noncognitive variables. Participants were 186 racially and ethnically diverse men and women living with HIV/AIDS who underwent comprehensive neurological, neuropsychological, and medical evaluations. Structural equation modeling was utilized to assess the extent to which information processing speed mediated the relationship between age, motor abnormalities, major depressive disorder, and reading level with other cognitive abilities. Age, motor dysfunction, reading level, and current major depressive disorder were all significantly associated with information processing speed. Information processing speed fully mediated the effects of age on learning, memory, and executive functioning and partially mediated the effect of major depressive disorder on learning and memory. The effect of motor dysfunction on learning and memory was fully mediated by processing speed. These findings provide support for information processing speed as a primary deficit, which may account, at least in part, for many of the other cognitive abnormalities recognized in complex HIV/AIDS populations. The association of age and information processing speed may account for HIV/aging synergies in the generation of CART-era cognitive abnormalities.

Tool vibration detection with eddy current sensors in machining process and computation of stability lobes using fuzzy classifiers

NASA Astrophysics Data System (ADS)

Devillez, Arnaud; Dudzinski, Daniel

2007-01-01

Today the knowledge of a process is very important for engineers to find optimal combination of control parameters warranting productivity, quality and functioning without defects and failures. In our laboratory, we carry out research in the field of high speed machining with modelling, simulation and experimental approaches. The aim of our investigation is to develop a software allowing the cutting conditions optimisation to limit the number of predictive tests, and the process monitoring to prevent any trouble during machining operations. This software is based on models and experimental data sets which constitute the knowledge of the process. In this paper, we deal with the problem of vibrations occurring during a machining operation. These vibrations may cause some failures and defects to the process, like workpiece surface alteration and rapid tool wear. To measure on line the tool micro-movements, we equipped a lathe with a specific instrumentation using eddy current sensors. Obtained signals were correlated with surface finish and a signal processing algorithm was used to determine if a test is stable or unstable. Then, a fuzzy classification method was proposed to classify the tests in a space defined by the width of cut and the cutting speed. Finally, it was shown that the fuzzy classification takes into account of the measurements incertitude to compute the stability limit or stability lobes of the process.

Surface inspection system for carriage parts

NASA Astrophysics Data System (ADS)

Denkena, Berend; Acker, Wolfram

2006-04-01

Quality standards are very high in carriage manufacturing, due to the fact, that the visual quality impression is highly relevant for the purchase decision for the customer. In carriage parts even very small dents can be visible on the varnished and polished surface by observing reflections. The industrial demands are to detect these form errors on the unvarnished part. In order to meet the requirements, a stripe projection system for automatic recognition of waviness and form errors is introduced1. It bases on a modified stripe projection method using a high resolution line scan camera. Particular emphasis is put on achieving a short measuring time and a high resolution in depth, aiming at a reliable automatic recognition of dents and waviness of 10 μm on large curved surfaces of approximately 1 m width. The resulting point cloud needs to be filtered in order to detect dents. Therefore a spatial filtering technique is used. This works well on smoothly curved surfaces, if frequency parameters are well defined. On more complex parts like mudguards the method is restricted by the fact that frequencies near the define dent frequencies occur within the surface as well. To allow analysis of complex parts, the system is currently extended by including 3D CAD models into the process of inspection. For smoothly curved surfaces, the measuring speed of the prototype is mainly limited by the amount of light produced by the stripe projector. For complex surfaces the measuring speed is limited by the time consuming matching process. Currently, the development focuses on the improvement of the measuring speed.

The effective forces transmitted by high-speed, low-amplitude thoracic manipulation.

PubMed

Herzog, W; Kats, M; Symons, B

2001-10-01

Twenty asymptomatic volunteers each received three spinal manipulative treatments to the thoracic spine. The treatments consisted of a straight posterior-to-anterior high-speed, low-amplitude thrust to the transverse process of T3-T10 using a reinforced hypothenar contact. All treatments were given by a full-time practicing clinician with 3 years of experience. The primary objective of this study was to quantify local measures of loading applied by the clinician on the volunteers during spinal manipulative treatments and to compare these local measures of loading with previously described global measures. The sparse information on the mechanics of spinal manipulative treatments deals exclusively with global force or pressure measurements. On the basis of these global data, incorrect conclusions may be drawn about the beneficial effects of spinal manipulative therapy, the loading of internal structures, and the risks associated with these treatments. Twenty asymptomatic subjects each received three posterior-to-anterior, high-speed, low-amplitude spinal manipulative treatments to the transverse process of the thoracic spine. Total force, local force, contact area, peak pressure, and average pressure at the contact interface between clinician and subject were measured continuously by use of a thin, flexible pressure pad. Local and global measures of loading were compared and analyzed by use of nonparametric statistics (alpha = 0.01). The average peak total force was 238.2 N. The average peak local force over a target area of 25 mm2 was 5 N, indicating that global measures of loading vastly overestimate the local effective forces at the target site. The peak pressure point moved, on average, 9.8 mm during the course of the manipulation. To the authors' best knowledge, this is the first study to quantify local, effective measures of loading and compare them with the global measures typically used. The conclusions are limited because the study used a single clinician. The effective loading of specific target sites is much smaller than the global measures might suggest. This result occurs because as the forces during spinal manipulative treatment increase, so does the contact area; therefore, much of the total treatment force is taken up by non-target-specific tissues. Because of the vast discrepancy between the global and local measures of loading, it is suggested that risk-benefit assessments of high-speed, low-amplitude spinal manipulative treatments should be made, including local measures of loading. Finally, because theoretical approaches and the inverse dynamics approach can provide only global measures of loading, the results of such studies should be interpreted with caution.

Quasi-Uniform High Speed Foam Crush Testing Using a Guided Drop Mass Impact

NASA Technical Reports Server (NTRS)

Jones, Lisa E. (Technical Monitor); Kellas, Sotiris

2004-01-01

A relatively simple method for measuring the dynamic crush response of foam materials at various loading rates is described. The method utilizes a drop mass impact configuration with mass and impact velocity selected such that the crush speed remains approximately uniform during the entire sample crushing event. Instrumentation, data acquisition, and data processing techniques are presented, and limitations of the test method are discussed. The objective of the test method is to produce input data for dynamic finite element modeling involving crash and energy absorption characteristics of foam materials.

Factors influencing the latency of simple reaction time

PubMed Central

Woods, David L.; Wyma, John M.; Yund, E. William; Herron, Timothy J.; Reed, Bruce

2015-01-01

Simple reaction time (SRT), the minimal time needed to respond to a stimulus, is a basic measure of processing speed. SRTs were first measured by Francis Galton in the 19th century, who reported visual SRT latencies below 190 ms in young subjects. However, recent large-scale studies have reported substantially increased SRT latencies that differ markedly in different laboratories, in part due to timing delays introduced by the computer hardware and software used for SRT measurement. We developed a calibrated and temporally precise SRT test to analyze the factors that influence SRT latencies in a paradigm where visual stimuli were presented to the left or right hemifield at varying stimulus onset asynchronies (SOAs). Experiment 1 examined a community sample of 1469 subjects ranging in age from 18 to 65. Mean SRT latencies were short (231, 213 ms when corrected for hardware delays) and increased significantly with age (0.55 ms/year), but were unaffected by sex or education. As in previous studies, SRTs were prolonged at shorter SOAs and were slightly faster for stimuli presented in the visual field contralateral to the responding hand. Stimulus detection time (SDT) was estimated by subtracting movement initiation time, measured in a speeded finger tapping test, from SRTs. SDT latencies averaged 131 ms and were unaffected by age. Experiment 2 tested 189 subjects ranging in age from 18 to 82 years in a different laboratory using a larger range of SOAs. Both SRTs and SDTs were slightly prolonged (by 7 ms). SRT latencies increased with age while SDT latencies remained stable. Precise computer-based measurements of SRT latencies show that processing speed is as fast in contemporary populations as in the Victorian era, and that age-related increases in SRT latencies are due primarily to slowed motor output. PMID:25859198

Influence of wind-speed on short-duration NO2 measurements using Palmes and Ogawa passive diffusion samplers

NASA Astrophysics Data System (ADS)

Masey, Nicola; Gillespie, Jonathan; Heal, Mathew R.; Hamilton, Scott; Beverland, Iain J.

2017-07-01

We assessed the precision and accuracy of nitrogen dioxide (NO2) concentrations over 2-day, 3-day and 7-day exposure periods measured with the following types of passive diffusion samplers: standard (open) Palmes tubes; standard Ogawa samplers with commercially-prepared Ogawa absorbent pads (Ogawa[S]); and modified Ogawa samplers with absorbent-impregnated stainless steel meshes normally used in Palmes tubes (Ogawa[P]). We deployed these passive samplers close to the inlet of a chemiluminescence NO2 analyser at an urban background site in Glasgow, UK over 32 discrete measurement periods. Duplicate relative standard deviation was <7% for all passive samplers. The Ogawa[P], Ogawa[S] and Palmes samplers explained 93%, 87% and 58% of temporal variation in analyser concentrations respectively. Uptake rates for Palmes and Ogawa[S] samplers were positively and linearly associated with wind-speed (P < 0.01 and P < 0.05 respectively). Computation of adjusted uptake rates using average wind-speed observed during each sampling period increased the variation in analyser concentrations explained by Palmes and Ogawa[S] estimates to 90% and 92% respectively, suggesting that measurements can be corrected for shortening of diffusion path lengths due to wind-speed to improve the accuracy of estimates of short-term NO2 exposure. Monitoring situations where it is difficult to reliably estimate wind-speed variations, e.g. across multiple sites with different unknown exposures to local winds, and personal exposure monitoring, are likely to benefit from protection of these sampling devices from the effects of wind, for example by use of a mesh or membrane across the open end. The uptake rate of Ogawa[P] samplers was not associated with wind-speed resulting in a high correlation between estimated concentrations and observed analyser concentrations. The use of Palmes meshes in Ogawa[P] samplers reduced the cost of sampler preparation and removed uncertainty associated with the unknown manufacturing process for the commercially-prepared collection pads.

Physical and electrical properties of melt-spun Fe-Si (3–8 wt%) soft magnetic ribbons

DOE PAGES

Overman, Nicole R.; Jiang, Xiujuan; Kukkadapu, Ravi K.; ...

2017-12-13

Fe-Si alloys ranging from 3 to 8 wt% Si were rapidly solidified using melt spinning. Wheel speeds of 30 m/s and 40 m/s were employed to vary cooling rates. Mössbauer spectroscopic studies indicated the Si content significantly influenced the number of Fe sites, relative abundance of various Fe species, and internal magnetic fields/structural environments. Wheel speed altered Fe speciation only in the 3 wt% sample. Scanning electron microscopy confirmed that increasing the wheel speed refined both the ribbon thickness and grain size. Electron backscatter diffraction results suggest tailoring melt spinning process parameters and alloy chemistry may offer the ability tomore » manipulate {001} texture development. In conclusion, electrical resistivity measurements were observed to increase in response to elevated Si content. Increased hardness was correlated to elevated Si content and wheel speed.« less

Ultrafast Imaging using Spectral Resonance Modulation

NASA Astrophysics Data System (ADS)

Huang, Eric; Ma, Qian; Liu, Zhaowei

2016-04-01

CCD cameras are ubiquitous in research labs, industry, and hospitals for a huge variety of applications, but there are many dynamic processes in nature that unfold too quickly to be captured. Although tradeoffs can be made between exposure time, sensitivity, and area of interest, ultimately the speed limit of a CCD camera is constrained by the electronic readout rate of the sensors. One potential way to improve the imaging speed is with compressive sensing (CS), a technique that allows for a reduction in the number of measurements needed to record an image. However, most CS imaging methods require spatial light modulators (SLMs), which are subject to mechanical speed limitations. Here, we demonstrate an etalon array based SLM without any moving elements that is unconstrained by either mechanical or electronic speed limitations. This novel spectral resonance modulator (SRM) shows great potential in an ultrafast compressive single pixel camera.

Physical and electrical properties of melt-spun Fe-Si (3–8 wt.%) soft magnetic ribbons

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

Overman, Nicole R.; Jiang, Xiujuan; Kukkadapu, Ravi K.

Fe-Si alloys ranging from 3 to 8 wt% Si were rapidly solidified using melt spinning. Wheel speeds of 30 m/s and 40 m/s were employed to vary cooling rates. Mössbauer spectroscopic studies indicated the Si content significantly influenced the number of Fe sites, relative abundance of various Fe species, and internal magnetic fields/structural environments. Wheel speed altered Fe speciation only in the 3 wt% sample. Scanning electron microscopy confirmed that increasing the wheel speed refined both the ribbon thickness and grain size. Electron backscatter diffraction results suggest tailoring melt spinning process parameters and alloy chemistry may offer the ability tomore » manipulate {001} texture development. Electrical resistivity measurements were observed to increase in response to elevated Si content. Increased hardness was correlated to elevated Si content and wheel speed.« less

Numerical simulation of humping phenomenon in high speed gas metal arc welding

NASA Astrophysics Data System (ADS)

Chen, Ji; Wu, Chuan-Song

2011-06-01

It is of great significance to obtain a thorough understanding of the physical mechanisms responsible for humping bead phenomenon in high speed gas metal arc welding (GMAW) in order to raise welding efficiency. Experiments were conducted to observe the weld pool behaviors in high speed GMAW, and it was found that both the severely deformed weld pool surface and strong backward flowing play a dominant role in humping bead formation. In this study, a mathematical model is developed to quantitatively analyze the forming mechanism of humping beads for high speed GMAW through considering both the momentum and heat content distribution of the backward flowing molten metal inside the weld pool. The transient development of temperature profiles in the weld pool with severe deformation demonstrates the humping bead forming process under some welding conditions. The predicted and measured humping bead dimensions are in agreement.

Physical and electrical properties of melt-spun Fe-Si (3–8 wt%) soft magnetic ribbons

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

Overman, Nicole R.; Jiang, Xiujuan; Kukkadapu, Ravi K.

Fe-Si alloys ranging from 3 to 8 wt% Si were rapidly solidified using melt spinning. Wheel speeds of 30 m/s and 40 m/s were employed to vary cooling rates. Mössbauer spectroscopic studies indicated the Si content significantly influenced the number of Fe sites, relative abundance of various Fe species, and internal magnetic fields/structural environments. Wheel speed altered Fe speciation only in the 3 wt% sample. Scanning electron microscopy confirmed that increasing the wheel speed refined both the ribbon thickness and grain size. Electron backscatter diffraction results suggest tailoring melt spinning process parameters and alloy chemistry may offer the ability tomore » manipulate {001} texture development. In conclusion, electrical resistivity measurements were observed to increase in response to elevated Si content. Increased hardness was correlated to elevated Si content and wheel speed.« less