Academic literature on the topic 'Performance-intensity function'
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Journal articles on the topic "Performance-intensity function"
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Boothroyd, Arthur. "The Performance/Intensity Function: An Underused Resource." Ear and Hearing 29, no. 4 (August 2008): 479–91. http://dx.doi.org/10.1097/aud.0b013e318174f067.
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Studebaker, Gerald A., Rebecca Taylor, and Robert L. Sherbecoe. "The Effect of Noise Spectrum on Speech Recognition Performance-Intensity Functions." Journal of Speech, Language, and Hearing Research 37, no. 2 (April 1994): 439–48. http://dx.doi.org/10.1044/jshr.3702.439.
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Articulation theory predicts that a subject’s absolute or masked threshold configuration will affect the slope of the speech recognition performance-intensity (P-I) function. This study was carried out to test that prediction. Performance-intensity functions for the Technisonic Studios W-22 recordings were obtained from 12 subjects with normal hearing. Four continuous thermal noise maskers, high-pass (HP) noise, white noise, ANSI noise, and talker-spectrum-matched (TSM) noise, were used to shape threshold. P-I function slopes for the averaged data ranged from about 1.6%o/dB in HP noise to about 6.7%/dB in TSM noise. At low to moderate speech intensity levels, the positions and slopes of the P- functions were accurately estimated by an articulation index-type model that included corrections for subject proficiency and for high- and low-frequency spread of masking. At higher intensity levels, performance was overestimated by the model.
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Mehren, Aylin, Cecilia Diaz Luque, Mirko Brandes, Alexandra P. Lam, Christiane M. Thiel, Alexandra Philipsen, and Jale Özyurt. "Intensity-Dependent Effects of Acute Exercise on Executive Function." Neural Plasticity 2019 (June 4, 2019): 1–17. http://dx.doi.org/10.1155/2019/8608317.
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Numerous studies suggest beneficial effects of aerobic exercise at moderate intensity on cognition, while the effects of high-intensity exercise are less clear. This study investigated the acute effects of exercise at moderate and high intensities on executive functions in healthy adults, including functional MRI to examine the underlying neural mechanisms. Furthermore, the association between exercise effects and cardiorespiratory fitness was examined. 64 participants performed in two executive function tasks (flanker and Go/No-go tasks), while functional MR images were collected, following two conditions: in the exercise condition, they cycled on an ergometer at either moderate or high intensity (each n=32); in the control condition, they watched a movie. Differences in behavioral performance and brain activation between the two conditions were compared between groups. Further, correlations between cardiorespiratory fitness and exercise effects on neural and behavioral correlates of executive performance were calculated. Moderate exercise compared to high-intensity exercise was associated with a tendency towards improved behavioral performance (sensitivity index d′) in the Go/No-go task and increased brain activation during hit trials in areas related to executive function, attention, and motor processes (insula, superior frontal gyrus, precentral gyrus, and supplementary motor area). Exercise at high intensity was associated with decreased brain activation in those areas and no changes in behavioral performance. Exercise had no effect on brain activation in the flanker task, but an explorative analysis revealed that reaction times improved after high-intensity exercise. Higher cardiorespiratory fitness was correlated with increased brain activation after moderate exercise and decreased brain activation after high-intensity exercise. These data show that exercise at moderate vs. high intensity has different effects on executive task performance and related brain activation changes as measured by fMRI and that cardiorespiratory fitness might be a moderating factor of acute exercise effects. Thus, our results may contribute to further clarify the neurophysiological mechanisms underlying the beneficial effects of exercise on cognition.
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Chang, Yu-Kai, and Jennifer L. Etnier. "Exploring the Dose-Response Relationship between Resistance Exercise Intensity and Cognitive Function." Journal of Sport and Exercise Psychology 31, no. 5 (October 2009): 640–56. http://dx.doi.org/10.1123/jsep.31.5.640.
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The purpose of this study was to explore the dose-response relationship between resistance exercise intensity and cognitive performance. Sixty-eight participants were randomly assigned into control, 40%, 70%, or 100% of 10-repetition maximal resistance exercise groups. Participants were tested on Day 1 (baseline) and on Day 2 (measures were taken relative to performance of the treatment). Heart rate, ratings of perceived exertion, self-reported arousal, and affect were assessed on both days. Cognitive performance was assessed on Day 1 and before and following treatment on Day 2. Results from regression analyses indicated that there is a significant linear effect of exercise intensity on information processing speed, and a significant quadratic trend for exercise intensity on executive function. Thus, there is a dose-response relationship between the intensity of resistance exercise and cognitive performance such that high-intensity exercise benefits speed of processing, but moderate intensity exercise is most beneficial for executive function.
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Schlauch, Robert S., and Craig C. Wier. "A Method for Relating Loudness-Matching and Intensity-Discrimination Data." Journal of Speech, Language, and Hearing Research 30, no. 1 (March 1987): 13–20. http://dx.doi.org/10.1044/jshr.3001.13.
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A method that allows direct comparisons between pure-tone loudness-matching and intensity-discrimination data in normal and hearing-impaired listeners is described. This method makes a minimal number of assumptions about the relations between loudness perception and intensity-discrimination performance. Loudness is considered to be related to overall, perceived stimulus magnitude and intensity-discrimination performance is considered to reflect the accuracy with which a loudness judgment can be made. Because pure-tone intensity-discrimination performance varies as a function of stimulus level in normal ears, the standard level required to produce a particular difference limen in an impaired ear can be inferred from normal-ear intensity-discrimination data. Thus, plotting standard levels yielding normal difference limens as a function of standard levels yielding the equivalent sized difference limens from a threshold-shifted ear produces a function directly comparable to loudness recruitment functions. If loudness-growth and intensity-difference limens were tightly coupled in threshold-shifted ears, then stimuli that yield equal size difference limens would be equally loud. This relation was tested by obtaining loudness-matching and intensity-discrimination data from normal-hearing listeners with thresholds shifted by a wideband noise and hearing-impaired listeners with cochlear-type hearing losses. The results from these listeners show similarities between the traditional loudness-recruitment functions and "intensity-recruitment" functions derived from the assumed relation between the two measures. The primary difference between the functions is at low and moderate sensation levels where loudness grows at a more rapid rate than the difference limen.
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Bhatti, M. T., S. Soomro, A. M. Bughio, T. A. Soomro, A. Anwar, and M. A. Soomro. "Active Contours Using Harmonic Global Division Function." Engineering, Technology & Applied Science Research 9, no. 4 (August 10, 2019): 4457–62. http://dx.doi.org/10.48084/etasr.2866.
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This paper presents the region-based active contours method based on the harmonic global signed pressure force (HGSPF) function. The proposed formulation improves the performance of the level set method by utilizing intensity information based on the global division function, which has the ability to segment out regions with higher intensity differences. The new energy utilizes harmonic intensity, which can better preserve the low contrast details and can segment complicated areas easily. A Gaussian kernel is adjusted to regularize level set and to escape an expensive reinitialization. Finally, a set of real and synthetic images are used for validation of the proposed method. Results demonstrate the performance of the proposed method, the accuracy values are compared to previous state-of-the-art methods.
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Penkman, Michael A., Catherine J. Field, Christopher M. Sellar, Vicki J. Harber, and Gordon J. Bell. "Effect of Hydration Status on High-Intensity Rowing Performance and Immune Function." International Journal of Sports Physiology and Performance 3, no. 4 (December 2008): 531–46. http://dx.doi.org/10.1123/ijspp.3.4.531.
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Purpose:This study determined the effect of dehydration and rehydration (DR) on performance, immune cell response, and tympanic temperature after high-intensity rowing exercis.Methods:Seven oarswomen completed two simulated 2000-m rowing race trials separated by 72 h in a random, cross-over design. One trial was completed in a euhydrated (E) condition and the other using a DR protocol.Results:The DR condition resulted in a 3.33 ± 0.14% reduction in body mass (P < .05) over a 24-h period followed by a 2-h rehydration period immediately before the simulated rowing race. There was a greater change in tympanic temperature observed in the DR trial (P < .05). There were increases in the blood concentration of leukocytes, lymphocytes, lymphocyte subsets (CD3+, CD3+/4+, CD3+/8+, CD3−/16+, CD4+/25+; P < .05) and decreases in lymphocyte proliferation and neutrophil oxidative burst activity immediately following the simulated race (P < .05) in both trials. Blood leukocyte and neutrophil concentrations were greater after exercise in the DR trial (P < .05). Whereas most immune measures returned to resting values after 60 min of recovery in both trials, lymphocyte proliferation and the concentrations of CD3+/4+ and CD4+/25+ cells were significantly lower than before exercise. Blood leukocyte and neutrophil concentrations were significantly higher before and after exercise in the E trial.Conclusion:The effects of dehydration/rehydration did not negatively influence simulated 2000-m rowing race performance in lightweight oarswomen but did produce a higher tympanic temperature and had a differential effect on blood leukocyte, neutrophil, and natural killer (CD3−/16+) cell concentrations after exercise compared with the euhydrated state.
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Sjödahl, Mikael. "Gradient Correlation Functions in Digital Image Correlation." Applied Sciences 9, no. 10 (May 24, 2019): 2127. http://dx.doi.org/10.3390/app9102127.
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The performance of seven different correlation functions applied in Digital Image Correlation has been investigated using simulated and experimentally acquired laser speckle patterns. The correlation functions were constructed as combinations of the pure intensity correlation function, the gradient correlation function and the Hessian correlation function, respectively. It was found that the correlation function that was constructed as the product of all three pure correlation functions performed best for the small speckle sizes and large correlation values, respectively. The difference between the different functions disappeared as the speckle size increased and the correlation value dropped. On average, the random error of the combined correlation function was half that of the traditional intensity correlation function within the optimum region.
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Storer, T., R. Casaburi, C. Gottron, D. Walsh, and J. D. Kopple. "LOW INTENSITY ENDURANCE TRAINING IMPROVES MUSCLE FUNCTION, PHYSICAL PERFORMANCE, AND FFM IN HEMODIALYSIS." Medicine & Science in Sports & Exercise 35, Supplement 1 (May 2003): S231. http://dx.doi.org/10.1097/00005768-200305001-01285.
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Buckley, Stephanie, Kelly Knapp, Amy Lackie, Colin Lewry, Karla Horvey, Chad Benko, Jason Trinh, and Scotty Butcher. "Multimodal high-intensity interval training increases muscle function and metabolic performance in females." Applied Physiology, Nutrition, and Metabolism 40, no. 11 (November 2015): 1157–62. http://dx.doi.org/10.1139/apnm-2015-0238.
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High-intensity interval training (HIIT) is a time-efficient method of improving aerobic and anaerobic power and capacity. In most individuals, however, HIIT using modalities such as cycling, running, and rowing does not typically result in increased muscle strength, power, or endurance. The purpose of this study is to compare the physiological outcomes of traditional HIIT using rowing (Row-HIIT) with a novel multimodal HIIT (MM-HIIT) circuit incorporating multiple modalities, including strength exercises, within an interval. Twenty-eight recreationally active women (age 24.7 ± 5.4 years) completed 6 weeks of either Row-HIIT or MM-HIIT and were tested on multiple fitness parameters. MM-HIIT and Row-HIIT resulted in similar improvements (p < 0.05 for post hoc pre- vs. post-training increases for each group) in maximal aerobic power (7% vs. 5%), anaerobic threshold (13% vs. 12%), respiratory compensation threshold (7% vs. 5%), anaerobic power (15% vs. 12%), and anaerobic capacity (18% vs. 14%). The MM-HIIT group had significant (p < 0.01 for all) increases in squat (39%), press (27%), and deadlift (18%) strength, broad jump distance (6%), and squat endurance (280%), whereas the Row-HIIT group had no increase in any muscle performance variable (p values 0.33–0.90). Post-training, 1-repetition maximum (1RM) squat (64.2 ± 13.6 vs. 45.8 ± 16.2 kg, p = 0.02), 1RM press (33.2 ± 3.8 vs. 26.0 ± 9.6 kg, p = 0.01), and squat endurance (23.9 ± 12.3 vs. 10.2 ± 5.6 reps, p < 0.01) were greater in the MM-HIIT group than in the Row-HIIT group. MM-HIIT resulted in similar aerobic and anaerobic adaptations but greater muscle performance increases than Row-HIIT in recreationally active women.
Dissertations / Theses on the topic "Performance-intensity function"
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Smith, Michelle R. "Effects of Pre-exercise Muscle Glycogen Status on Muscle Phosphagens, Sarcoplasmic Reticulum Function, and Performance During Intermittent High Intensity Exercise." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/34813.
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Eight competitive cyclists performed two cycling trials, one following a high
carbohydrate diet (H-CHO) and the other following a low carbohydrate diet (L-CHO).
Trials consisted of repeated 60s maximal effort sprints to fatigue at a workload designed
to elicit 125-135% VO2peak at 90rpm. Three min of recovery separated sprints. Muscle
biopsies taken at rest (biopsy 1), 85% max interval rpm (biopsy 2), and 70% max interval
rpm (biopsy 3) revealed a main effect of diet on muscle glycogen levels: 609 ± 38 HCHO
vs. 390 ± 42 mmol/kgdw L-CHO at biopsy 1, 383 ± 29 vs. 252 ± 28 mmol/kgdw at
biopsy 2, and 346 ± 29 vs. 196 ± 18 mmol/kgdw at biopsy 3 (p<0.01). Similar decreases
in muscle glycogen (45%), creatine phosphate (CP) (35%), and sarcoplasmic reticulum
(SR) Ca2+-uptake (56%) were shown in both trials from biopsy 1 to 3. SR Ca2+-release
decreased by 53% in H-CHO subjects and 36% in L-CHO subjects. Total exercise time
tended to be longer in H-CHO than L-CHO subjects (57.5 ± 10 vs. 42.0 ± .89min)
(p=0.09). H-CHO subjects exercised significantly longer than L-CHO subjects from
biopsy 2 to 3 (33.6 ± 10 vs. 18 ± 3.6min) (p< 0.05). Results suggest that fatigue from 40-
60min of intermittent 60s high intensity cycling intervals is associated with reductions in
muscle glycogen, CP, and SR function, and that the latter part of performance is impaired
by low muscle glycogen. These data do not support a relationship between muscle
glycogen status and SR function in intermittent high intensity exercise.Master of Science
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Bunker, Lisa Dawn. "Development of Tongan Materials for Determining Speech Recognition Thresholds." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2419.pdf.
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Al, Matar Waseem. "Speech Audiometry: Arabic Word Recognition Test for Adults." Kent State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=kent1627046045659542.
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Taylor, Brandon Brian. "Development of Psychometrically Equivalent Speech Audiometry Materials for Measuring Speech Recognition Thresholds in Native Tagalog Speakers." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3348.
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In addition to the use of pure-tones for testing hearing, speech signals are highly valuable diagnostic tools for identifying and evaluating hearing impairment. Speech audiometry involves the implementation of such signals in the measurement of hearing acuity. One aspect of speech audiometry involves assessment of the speech recognition threshold (SRT) which evaluates an individual's ability to hear and understand speech. While live speech has been used in the past to assess SRT, recorded materials are preferred and have been shown to be advantageous over live speech. High-quality digitally recorded speech audiometry materials have been available in English for some time, but assessment of individuals using speech materials from a language that they do not speak natively has been shown to be both inadequate and inaccurate. Speech audiometry materials have recently become available in many languages. Currently, however, there are no known published recordings for assessment of SRT in the Tagalog language. The goal of this study was to develop psychometrically equivalent speech audiometry materials for measuring speech recognition threshold in Tagalog. During this study Tagalog words were initially recorded by a native speaker selected for accent and vocal quality. The words were reduced down to 90 words to be evaluated in the study. Each of the 90 trisyllabic words were evaluated at 2 dB increments from -10 to 16 dB HL by 20 native Tagalog speakers, all having normal hearing. Based on the results, 34 trisyllabic Tagalog words were selected based on their familiarity to native listeners, relative homogeneity with regards to audibility and psychometric function slope. Each word was then adjusted to make the 50% performance threshold equal to the mean PTA of the 20 research participants (4.3 dB HL). The final edited words were then digitally recorded onto compact disc for distribution and for use in assessing SRT in native Tagalog speakers worldwide.
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Newman, Jennifer Lane. "Development of Psychometrically Equivalent Speech Recognition Threshold Materials for Native Speakers of Samoan." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2214.
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The speech recognition threshold (SRT) is an important measure, as it validates the pure-tone average (PTA), assists in the diagnosis and prognosis of hearing impairments, and aids in the identification of non-organic hearing impairments. Research has shown that in order for SRT testing to yield valid and reliable measures, testing needs to be performed in the patient's native language. There are currently no published materials for SRT testing in the Samoan language. As a result, audiologists are testing patients with English materials or other materials not of the patient's native language. Results produced from this manner of testing are confounded by the patient's vocabulary knowledge and may reflect a language deficit rather than a hearing loss. The present study is aimed at developing SRT materials for native speakers of Samoan to enable valid and reliable measures of SRT for the Samoan speaking population. This study selected 28 trisyllabic Samoan words that were found to be relatively homogeneous in regard to audibility and psychometric function slope. Data were gathered on 20 normal hearing native speakers of Samoan and the intensity of each selected word was adjusted to make the 50% performance threshold of each word equal to the mean PTA of the 20 research participants (5.33 dB HL). The final edited words were digitally recorded onto compact disc to allow for distribution and use for SRT testing in Samoan.
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Mangum, Tanya Crawford. "Performance Intensity Functions for Digitally Recorded Japanese Speech Audiometry Materials." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd838.pdf.
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Dawson, Nicole T. "Examining the Effects of A Moderate-Intensity Home-Based Functional Exercise Intervention on Cognition and Function in Individuals with Dementia." Cleveland State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=csu1435768988.
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Bonnevie, Tristan. "Nouveaux outils et optimisation des outils existants pour la réhabilitation respiratoire et la ré-autonomisation des patients atteints d'un handicap ventilatoire. Chronic obstructive pulmonary disease Six-minute stepper test to set pulmonary rehabilitation intensity in patients with COPD - a retrospective study Can the six-minute stepper test be used to determine the intensity of endurance training in early stage COPD : a multicenter observational study The six-minute stepper test is related to muscle strength but cannot substitute for the one repetition maximum to prescribe strength training in patients with COPD People undertaking pulmonary rehabilitation are willing and able to provide accurate data via a remote pulse oximetry system : a multicentre observational study Mid-term effects of pulmonary rehabilitation on cognitive function in people with severe chronic obstructive pulmonary disease NIV is not adequate for high intensity endurance in COPD Home-based neuromuscular electrical stimulation as an add-on to pulmonary rehabilitation does not provide further benefits in patients with chronic obstructive pulmonary disease : a multicenter randomized trial Lumbar transcutaneous electrical nerve stimulation to improve exercise performance in COPD patients Advanced telehealth technology improves in-home pulmonary rehabilitation for people with stable chronic obstructive pulmonary disease : a systematic review Nasal high flow for stable patients with chronic obstructive pulmonary disease : a systematic review and meta-analysis." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR024.
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La réhabilitation respiratoire (RR) est recommandée dans la prise en soin des patients atteints d’un handicap ventilatoire afin d’améliorer leur qualité de vie. Malgré une efficacité clairement établie, très peu de patients en bénéficient et les modalités optimales d’entrainement restent à définir. L’utilisation des outils existants et des nouveaux outils pour optimiser l’accès au programme et ses effets représentent des développements majeurs qui méritent d’être évalués. Dans le cadre de cette thèse, nous avons cherché à aborder ces deux problématiques (1) en tentant de proposer un modèle de RR délocalisée hors des centres tout en évaluant les freins à ce modèle et (2) en explorant la place de différents adjuvants à la RR afin d’en optimiser les bénéfices. Dans la première partie, nous avons montré, à travers plusieurs études rétrospectives et une contribution originale prospective multicentrique, que le test stepper de six minutes peut être utilisé pour prescrire l’entrainement en endurance, particulièrement pour les patients présentant une forme légère à modérée de bronchopneumopathie chronique obstructive (BPCO), mais pas pour prescrire le renforcement musculaire. Par ailleurs, nous avons montré dans une population de 105 patients adressés en RR que l’utilisation d’un dispositif de telemonitoring était faisable, valide et largement accepté. Enfin, nous avons exploré la prévalence des dysfonctions cognitives, autre conséquence systémique de la BPCO qui pourrait compromettre la délocalisation du programme, et avons montré que cette prévalence était très élevée (environ 75% des patients) mais que ces troubles cognitifs pouvaient s’améliorer après la RR et ne semblaient pas influencer l’utilisation d’un dispositif de telemonitoring. Dans la seconde partie, nous avons évalué la place de différents adjuvants à la RR utilisés pour en potentialiser les bénéfices. Dans une étude en cross-over menée chez 21 patients atteints de BPCO, nous avons montré que la ventilation non invasive ne permettait pas d’améliorer la capacité à l’exercice en endurance en raison d’une limitation technologique du ventilateur. A travers une étude contrôlée randomisée multicentrique menée chez 73 patients atteints de BPCO sévère à très sévère, nous avons montré que la stimulation électrique excito-motrice à domicile, réalisée en plus d’un programme de RR, n’apportait pas davantage de bénéfices sur la qualité de vie ou la capacité à l’exercice. Enfin, à travers une étude randomisée en cross-over et en double aveugle menée chez 10 patients, nous n’avons pas pu montrer l’intérêt de la stimulation électrique nerveuse transcutanée pour améliorer leur capacité à l’exercice en endurance. Enfin, dans la dernière partie, nous avons présenté les recherches actuellement menées au sein de notre laboratoire, faisant suite aux contributions originales décrites au cours de cette thèse, ainsi que de nouvelles pistes de recherche afin de poursuivre les thématiques explorées. Ainsi, deux revues de littérature et méta-analyses (l’une d’elle portant sur le haut débit nasal et l’autre sur l’utilisation des technologies de santé avancées pour réaliser la RR respiratoire à domicile) serviront de base pour de futurs travauxPulmonary rehabilitation (PR) is recommended in the management of subjects with ventilatory impairment to improve their quality of life. Although a large body of evidence support its use, only few subjects benefit from it and the optimal training modality has not been determined yet. In this context, the use of new and existing tools to optimize access as well as the effects of the program are major developments that deserve to be studied. As part of this thesis, we sought to explore these two major issues (1) by considering a rehabilitation model relocated outside the PR centres while assessing the obstacles to this model and (2) exploring the effectiveness of different add-on to PR in further optimizing the benefits of the program. In the first part, we have shown, through several retrospective studies and an original prospective multicentre contribution, that the six-minute stepper test can be used to prescribe endurance training, particularly for those patients with a mild to moderate chronic obstructive pulmonary disease (COPD), but not to prescribe muscle strengthening. Furthermore, we have shown in a cohort of 105 subjects referred for PR that the use of a remote tele monitoring device was feasible, valid and widely accepted. Finally, we explored the prevalence of cognitive dysfunction, another systemic impairment of COPD that could compromise the relocation of the program, and showed that it was a very common condition (around 75% of the subjects) but that it could improve following PR and did not seem to influence the use of a remote tele monitoring device. In the second part, we evaluated the effects of different add-on used to potentiate the benefits of the PR program. In a cross-over study of 21 COPD patients, we showed that non-invasive ventilation did not improve endurance exercise capacity due to technological limitation of the ventilator. Through a multicentre randomized controlled study carried out in 73 patients with severe to very severe COPD, we have shown that neuromuscular electrical stimulation at home, performed in addition to a PR program, did not provide further benefits on quality of life or exercise capacity. Finally, through a randomized cross-over double-blind study carried out in 10 patients, we were unable to show the effectiveness of transcutaneous nerve electrical stimulation in improving their endurance exercise capacity. Finally, in a last part, we highlighted the research currently carried out in our laboratory following the original contributions described during this thesis, as well as new area of research in order to pursue the themes explored. Thus, two systematic reviews and meta-analysis (the first about nasal high flow therapy in subjects with stable COPD and the second about the use of advanced telehealth technologies to deliver PR) will serve as a basis for future research
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Badzinski, Diane Marie. "Developmental differences in children's inferential performance as a function of message intensity." 1988. http://catalog.hathitrust.org/api/volumes/oclc/18653364.html.
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Thesis (Ph. D.)--University of Wisconsin--Madison, 1988.Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 259-275).
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YUAN, HUA-HONG, and 袁華宏. "Effects of High-intensity Intermittent Spinning Course on Body Composition and Lower Extremity Functional Performance in Obese Middle-aged Adults." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/t59z8n.
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碩士國立體育大學
運動與健康科學學院
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PURPOSE: The spinning is a bicycle that can adjust the resistance and has less impact on the joints of lower extremities than the treadmill. High-intensity intermittent exercise is an efficient exercise mode that simultaneously challenges both aerobic and anaerobic systems. This study was to investigate the effects of high-intensity interval training with a spinning on the body composition and functional performance of lower extremity in obese middle-aged adults. METHODS: A total of 24 subjects (60.3±3.21 years old) were enrolled in this study and were assigned into exercise group (n=10) and control group (n=14) for 12-week intervention. Body composition and functional performance of the lower extremities were evaluated before and after the intervention. The exercise group performed supervised high-intensity intermittent spinning training 50 minutes per time, 3 times per week for 12 weeks. The control group maintained its regular lifestyle. The differences between the control group and the exercise group at pre-test and post-test were examined by the independent T test. The statistically significant level was set at α =.05. RESULTS: The 12-week high-intensity intermittent spinning program did not significantly alter the body composition in middle-aged obese adults, including body weight, body mass index, waist circumference, whole body fat, lower body fat, and skeletal muscle mass. However, the performance of the lower extremity significantly improved with exercise intervention, including the splitting of the legs, the 5-times chair stands test, 30-second chair-stand test, and the 2.44m up-and-go and stair climbing test. CONCLUSION: The 12-week high-intensity intermittent spinning course effectively improved the performance of the lower extremities in obese middle-aged adults even though body composition was not altered.
Books on the topic "Performance-intensity function"
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Tolfrey, Keith, and James W. Smallcombe. High-intensity interval training. Edited by Neil Armstrong and Willem van Mechelen. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198757672.003.0035.
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High-intensity interval training (HIIT) is characterized by brief, intermittent bursts of near- or maximal-intensity exercise, interspersed by periods of active or passive recovery. The limited available evidence suggests that HIIT is an efficacious training method for young athletes. The effect of HIIT on cardiorespiratory fitness, endurance performance, explosive strength, and sport-specific performance has been examined in a range of young athletic populations from various sports. Furthermore, promising preliminary findings suggest that HIIT may confer further benefits to a range of health outcome measures including fasting insulin, lipoproteins, systolic blood pressure, and endothelial function; obese youth may benefit particularly from this type of training. Improved cardiorespiratory fitness has been observed consistently after HIIT in athletic and non-athletic populations. Larger studies, extended over longer periods, that include valid measures of exercise compliance, tolerance, and enjoyment are required to further delineate the priority that could be afforded to this type of training.
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Mahon, Anthony D. Aerobic training. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199232482.003.0039.
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Aerobic training is defined as exercise training that involves whole body endurance activity that is sustained for a sufficient length of time and at a sufficient intensity in order to improve cardiorespiratory fitness.1 The effect of aerobic training on physiological function in children has been investigated for nearly four decades. Some of this research has focused on the health-related benefits of this type of training on children and adolescents and for good reason. With increasing rates of obesity, type 2 diabetes, metabolic syndrome, and many other physical inactivity-related disorders, there is ample reason to discern the health-related effects of aerobic training during the paediatric years.2,3 However, there also has been a concerted effort to study the effect of aerobic training on the physiological adaptations, particularly maximal oxygen uptake ( V · O 2 max), that are associated with endurance performance.4 This chapter will focus on the latter consideration and will examine the effect of aerobic training in apparently healthy children and adolescents.
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Roy, Kaushik. Indian Army and the First World War. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199485659.001.0001.
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Accustomed to conducting low-intensity warfare before 1914, the Indian Army learnt to engage in high-intensity conventional warfare during the course of World War I, thereby exhibiting a steep learning curve. Being the bulwark of the British Empire in South Asia, the ‘brown warriors’ of the Raj functioned as an imperial fire brigade during the war. Studying the Indian Army as an institution during the war, Kaushik Roy delineates its social, cultural, and organizational aspects to understand its role in the scheme of British imperial projects. Focusing not just on ‘history from above’ but also ‘history from below’, Roy analyses the experiences of common soldiers and not just those of the high command. Moreover, since society, along with the army, was mobilized to provide military and non-military support, this volume sheds light on the repercussions of this mass mobilization on the structure of British rule in South Asia. Using rare archival materials, published autobiographies, and diaries, Roy’s work offers a holistic analysis of the military performance of the Indian Army in major theatres during the war.
Book chapters on the topic "Performance-intensity function"
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Kumar, Ram, Sweta Rani, Abahan Sarkar, and Fazal Ahmed Talukdar. "GPU-Based Level Set Method for MRI Brain Tumor Segmentation Using Modified Probabilistic Clustering." In Medical Imaging, 1053–78. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0571-6.ch043.
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The level set method (LSM) has been widely used in image segmentation due to its intrinsic nature which allows handling complex shapes and topological changes easily. We propose a new level set algorithm, which is based on probabilistic c mean objective function which incorporates intensity inhomogeneity in image and robust to noise. The computational complexity of the proposed LSM is greatly reduced by using highly parallelizable lattice Boltzmann method (LBM). So the proposed algorithm is effective and highly parallelizable. The proposed LSM is implemented using Experimental results demonstrate the performance of the proposed method.
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S. P., Shantharajah, Ramkumar T, and Balakrishnan N. "An Image De-Noising Method Based on Intensity Histogram Equalization Technique for Image Enhancement." In Advanced Image Processing Techniques and Applications, 121–32. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-2053-5.ch005.
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Image enhancement is a quantifying criterion for sharpening and enhancing image quality, where many techniques are empirical with interactive procedures to obtain précised results. The proposed Intensity Histogram Equalization (IHE) approach conquers the noise defects that has a preprocessor to remove noise and enhances image contrast, providing ways to improve the intensity of the image. The preprocessor has the mask production, enlightenment equalization and color normalization for efficient processing of the images which generates a binary image by labeling pixels, overcomes the non-uniform illumination of image and classifies color capacity, respectively. The distinct and discrete mapping function calculates the histogram values and improves the contrast of the image. The performance of IHE is based on noise removal ratio, reliability rate, false positive error measure, Max-Flow Computational Complexity Measure with NDRA and Variation HOD. As the outcome, the different levels of contrast have been significantly improved when evaluated against with the existing systems.
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S. P., Shantharajah, Ramkumar T, and Balakrishnan N. "An Image De-Noising Method Based on Intensity Histogram Equalization Technique for Image Enhancement." In Computer Vision, 311–23. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-5204-8.ch012.
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Image enhancement is a quantifying criterion for sharpening and enhancing image quality, where many techniques are empirical with interactive procedures to obtain précised results. The proposed Intensity Histogram Equalization (IHE) approach conquers the noise defects that has a preprocessor to remove noise and enhances image contrast, providing ways to improve the intensity of the image. The preprocessor has the mask production, enlightenment equalization and color normalization for efficient processing of the images which generates a binary image by labeling pixels, overcomes the non-uniform illumination of image and classifies color capacity, respectively. The distinct and discrete mapping function calculates the histogram values and improves the contrast of the image. The performance of IHE is based on noise removal ratio, reliability rate, false positive error measure, Max-Flow Computational Complexity Measure with NDRA and Variation HOD. As the outcome, the different levels of contrast have been significantly improved when evaluated against with the existing systems.
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Ciulla, Carlo. "On the Implications of the Sub-Pixel Efficacy Region and the Bridging Concept of the Unifying Theory." In Improved Signal and Image Interpolation in Biomedical Applications, 471–511. IGI Global, 2009. http://dx.doi.org/10.4018/978-1-60566-202-2.ch020.
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The last chapter of the book reports on concluding remarks recalling to the reader the message given through these works and also recalling the proposed novelty. The novelty is discussed within the context of the current literature with specific attention to other works devoted to the improvement of the interpolation error. The reader is acknowledged that the methodological approach outlined through the theory can be seen as a viable pathway to follow in order to conceptualize interpolation in an innovative and alternative manner. This descends from the adoption of the mathematical formulation that is dependent on the joint information content of node intensity and curvature of the interpolation function and has brought to the determination of a viable option to adopt when re-sampling the signal (image). Re-sampling inherent to interpolation can be performed at sub-pixel locations that are not necessarily the same as the given misplacement neither are they necessarily the same pixel-by-pixel. This is because of the variability of pixel intensity and curvature of the interpolation function at the neighborhood and between neighborhoods and also because such variability corresponds to various signal shape characteristics. The reader is informed that within the context of a paradigm to be used for the improvement of the interpolation error it is of relevance to include the curvature in the methodology that is chosen to improve the approximation capability of a given interpolation function. The focus is also towards the evidence that local re-sampling is capable of changing the band-pass filtering property of the interpolation functions. Also, a study is undertaken to determine how beneficial is the application of the Sub-pixel Efficacy Region in the estimation of signals at unknown time-space locations and this is done for the one-dimensional interpolation functions presented in the book. It is also shown that the SRE-based interpolation functions are capable to determine error improvement and to be more accurate with respect to the classic interpolation functions in the estimation of signals at locations that are not captured by the sampling frequency because of the Nyquist’s theorem constraint. Also, based on the same data, the effect of the sampling resolution is studied on the interpolation error and the interpolation error improvement. Consequentially, it is outlined the licit conclusion that under the umbrella of the unifying framework proposed within the theory, the sampling resolution influences both interpolation error and interpolation error improvement obtained from the SRE-based functions. Finally the chapter reports on the investigation of the influence of the SCALE parameter and on the performance comparison across classic and SRE-based interpolation functions. The SCALE parameter is employed to scale the convolution of the pixel intensities determined through the polynomials forms: quadratic and cubic B-Splines, Lagrange, and also to scale the numerical values of the sums of cosine and sine functions of the Sinc interpolation function.
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Sylvies, Fiona R., and Myrvin H. Ellestad. "Cardiovascular and Pulmonary Responses to Exercise." In Ellestad's Stress Testing, edited by Gregory S. Thomas, L. Samuel Wann, and Myrvin H. Ellestad, 373–412. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190225483.003.0020.
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The chapter Cardiovascular and Pulmonary Responses to Exercise reviews the changes in cardiac function when called upon to increase its output of oxygenated blood during exercise. A deep understanding of exercise physiology enhances one’s ability to understand the pathophysiology of ischemia and coronary artery disease (CAD) inherent in the performance of stress testing. With the onset of exercise, the body exhibits an almost immediate response through alterations in heart rate, preload, contractility, stroke volume, and coronary blood flow, all to compensate for augmented metabolic demands. Individual characteristics such as age, sex, and fitness impact a person’s physiological response to exertion. Differences in exercise modality, duration, intensity, and frequency will provoke unique responses, which can be utilized to design exercise prescriptions specific to a patient’s goals and medical needs.
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Angelopoulos, Pavlos, Konstantinos Mylonas, Grigorios Tsigkas, Elias Tsepis, Evdokia Billis, and Konstantinos Fousekis. "Blood Flow Restriction Training in Cardiovascular Disease Patients." In Recent Advances in Sport Science [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96076.
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Over the past two decades, blood flow restriction training (BFRT) has gained popularity not only in athletic performance training, but also with many researchers and physical therapists as an innovative rehabilitation tool. Blood flow restriction (BFR) exercise is a novel exercise modality in clinical settings, which induces muscle hypertrophy and increases strength with low to moderate training intensity through increased anabolic processes mediated by BFR (usually with cuff inflation). BFR limits arterial and venous blood flow and leads to blood pooling, which could increase the effects of exercise-induced training. Strength training at lower intensities (20–40% of maximum strength) in combination with BFR showed similar effects on muscle hypertrophy as training at 70% strength level without BFR. In this context, considering that periods of immobilization (or reduced functionality) due to pathology, injury, or surgery cause harmful effects on muscle mass and strength in both young and old people, muscular adaptations of occlusion exercise could be beneficial to the elderly and post-operative patients in rehabilitation regarding muscle regeneration. Furthermore, as this type of exercise does not require high loads, it might be a feasible method in cardiac rehabilitation. Therefore, this chapter aims to review all recent literature regarding the impact of low-load BFR resistance training in patients with cardiovascular pathologies on muscle strength and hypertrophy, vascular function, safety, cardiovascular responses, and inflammatory markers.
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Kumar, Rajeev, and Ashraf Hossain. "Cooperative Relaying Communication in IoT Applications for 5G Radio Networks." In Handbook of Research on Innovations and Applications of AI, IoT, and Cognitive Technologies, 26–41. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-6870-5.ch002.
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This chapter presents cooperative relaying networks that are helpful in Internet of Thing (IoT) applications for fifth-generation (5G) radio networks. It provides reliable connectivity as the wireless device is out of range from cellular network, high throughput gains and enhance the lifetime of wireless networks. These features can be achieved by designing the advanced protocols. The design of advanced protocols plays an important role to combat the effect of channel fading, data packet scheduling at the buffered relay, average delay, and traffic intensity. To achieve our goals, we consider two-way cooperative buffered relay networks and then investigate advanced protocols such as without channel state information (CSI) i.e., buffer state information (BSI) only and with partial transmit CSI i.e., BSI/CSI with the assistance of one dimensional Markov chain and transmission policies in fading environment. The outage probability of consecutive links and outage probability of multi-access and broadcast channels are provided in closed-form. Further, the buffered relay achieves maximum throughput gains in closed-form for all these protocols. The objective function of throughput of the buffered relay is evaluated in fractional programming that is transformed into linear program using standard CVX tool. Numerical results show that our proposed protocols performance better as compared to conventional method studied in the literature. Finally, this chapter provides possible future research directions.
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Neji, Mahmoudi, Mahdhi Mosbah, and Mars Mohamed. "Effects of Arbuscular Mycorrhizal Fungi on Plant Adaptation to Arid Ecosystem of Bou-Hedma National Park in Tunisia." In Natural Resources Management and Biological Sciences. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.92087.
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Plants interact with beneficial microbes living in their rhizosphere, promoting their growth and development. In arid ecosystems, specific plant-associated microbes grant plants access to nutrients that would otherwise be inaccessible. Arbuscular mycorrhizal fungi (AMF) are probably one of the better known belowground functional networks with plants. AMF plays a crucial role in plant performance and consequently in ecosystem functioning. AMF activities also determine the bio-availability of nutrients and therefore soil fertility. The main objective of the present study was to evaluate the plant-AMF interactions on soil functions under arid ecosystem in Tunisia. AMF colonization was evaluated by visual observation of AMF in fine roots of Astragalus corrugatus and Lotus creticus on Bou-Hedma National Park in Tunisia. Mycorrhizal colonization varied between plants, and the spore number was significantly different across rhizosphere soils. Statistical analysis showed a clearly positive correlation between the number of spores and plant-mycorrhizal intensity. For microbiological proprieties, our results showed that mycorrhizal plants improved significantly the different microbiological parameters. The results of the present study specified the association plant-AMF and highlight AMF importance as a tailored mechanism of plant adaptation to arid ecosystems.
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Wang, Gai-Ge, Amir H. Gandomi, Amir H. Alavi, and Yong-Quan Dong. "A Hybrid Meta-Heuristic Method Based on Firefly Algorithm and Krill Herd." In Advances in Computer and Electrical Engineering, 505–24. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9479-8.ch019.
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This study proposes a new firefly-inspired krill herd (FKH) optimization method based on integration of firefly and krill herd algorithms. FKH introduces an attractiveness and light intensity updating (ALIU) operator originally used in firefly algorithm into the krill herd method. This is basically done to improve local search technique and promote the diversity of the population to avoid a premature convergence. Moreover, an elitism strategy is adopted to maintain the optimal krill with the best fitness when updating the krill. The performance of the FKH method is verified using fifteen different benchmark functions. The results indicate that FKH performs more accurate and effective than the basic krill herd and other optimization algorithms.
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Haida, Munetaka. "Implications of NIRS Brain Signals." In Advances in Bioinformatics and Biomedical Engineering, 120–28. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2113-8.ch013.
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Near Infrared Spectroscopy (NIRS) is commonly used for functional brain studies. With this method, brain signals can be easily obtained, but the interpretation of these signals still remains unclear. This chapter provides a simple model to interpret the NIRS signal, which is based on the following assumptions: 1. The NIRS signal may reflect Hb levels only in the capillaries and not in large vessels; 2. The brain has a lighter color than the other tissues, indicating that the Hb concentration in brain tissue is very low and intensity level of the NIRS signal is very high; 3. A photon that hits a large vessel is too weak to be detected in the surrounding high signal environment; 4. Cerebral blood flow (CBF) can be separated into cross-sections (the number of capillary beds) that are multiplied by the velocity. This model can explain the typical signal pattern observed during task performance, where oxy-Hb levels increase and deoxy-Hb levels slightly decrease.
Conference papers on the topic "Performance-intensity function"
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He, Qifan, and Mohammed F. Daqaq. "Influence of Potential Function Asymmetries on the Performance of Nonlinear Energy Harvesters Under White Noise." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-34397.
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To improve the broadband transduction capabilities of vibratory energy harvesters (VEHs) under random and non-stationary excitations, many researchers have resorted to purposefully introducing nonlinearities into the restoring force of the harvester. While performing this task, it is often very challenging to maintain a perfectly symmetric restoring force which usually yields a VEH with an asymmetric potential energy function. This paper investigates the influence of potential function asymmetries on the performance of nonlinear VEHs under white noise inputs. To that end, a quadratic nonlinearity is introduced into the restoring force of the harvester and its influence on the mean power for both mono- and bi-stable potentials is investigated. It is shown that, for VEHs with a mono-stable potential function, the mean output power increases with the degree of potential function asymmetry. On the other hand, for energy harvesters with a bi-stable potential function, asymmetries in the restoring force appear to worsen performance especially for low to moderate noise intensities. When the noise intensity becomes sufficiently large, the influence of the potential function’s asymmetry on the mean power diminishes. Results also reveal that a VEH with a symmetric bi-stable potential function produces higher mean power levels than the one with the most asymmetric mono-stable potential. As such, it is concluded that a VEH with a bi-stable symmetric potential is most desirable to improve performance under white noise.
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Hines, A., and N. Harte. "Simulated performance intensity functions." In 2011 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2011. http://dx.doi.org/10.1109/iembs.2011.6091804.
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King, H. L. "Performance analysis of SOHO in DSSS composite neighbour sets: A function of Eb/No and BER influenced by peak electromagnetic field intensity of an TV-element linear array antenna." In 2010 IEEE Region 10 Conference (TENCON 2010). IEEE, 2010. http://dx.doi.org/10.1109/tencon.2010.5686556.
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Nikparto, Ali, and Meinhard T. Schobeiri. "A New Physics Based Unsteady Transition Model Using the Universal Intermittency Function." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90585.
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Abstract The flow inside a gas turbine engine has unique complexities. One of the important characteristics of such flow field is the existence of periodic unsteady wakes, originating from stator–rotor interaction. The unsteady wakes, with their highly vortical core, impinge on the downstream blade surfaces and cause an intermittent transition of the boundary layer from laminar to turbulent. The relative intermittency value corresponding to the wake vortical core and the calm region outside the wake, irrespective of freestream turbulence intensity and wake frequency, exhibits a universal behavior which is best described by the universal intermittency function of Chakka and Schobeiri [1, 2]. This study aims at introducing a new physics-based universal intermittency function that in conjunction with the current turbulence models accurately predicts the unsteady behavior of an intermittent flow. For that reason, a transport equation for turbulence intermittency was proposed based on this function and was integrated into a RANS based solver with k-ω turbulence model. The model was tested for reliability. Experimental aerodynamics and heat transfer measurements conducted at Turbomachinery Performance and Flow research Lab (TPFL) at Texas A&M University, were used as benchmark tests. For experimental measurements, an unsteady linear cascade facility in TPFL was used to produce the periodic unsteady flow condition. Moving wakes, originating from upstream blades, were simulated in this facility by rods attached to two parallel timing belts in front of the turbine blades. Heat transfer measurements along the suction surface were conducted utilizing a specially manufactured blade with an internal heater core, instrumented with liquid crystal. All Measurements and calculations were conducted at Reynolds number of 264,000. The computational results, obtained from implementing the new enhanced intermittency transport equation into the solver, are compared with (a) experimental measurements and (b) with the computational results from RANS that incorporates Langtry-Menter [3, 4] method.
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Varfolomeyev, Igor, and Dieter Beukelmann. "Analytical Solutions and Tools for Assessment of Surface Cracks in Cylindrical Components." In ASME 2008 Pressure Vessels and Piping Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/pvp2008-61566.
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The paper reviews some advanced stress intensity factor solutions derived for analyses of axial and circumferential surface cracks in cylindrical components subjected to variable stress fields. The solutions are examined considering their validity ranges with respect to the crack and cylinder geometry, ability to account for a complex stress distribution in the pipe wall, as well as their accuracy. A method for estimating errors in numerical stress intensity factor solutions is introduced and applied to a particular set of data. Examples of a leak-before-break assessment and crack growth calculations under thermal fatigue loading are included to demonstrate the solutions performance. The considered analytical stress intensity factor solutions yield close results provided that the stress field in the prospective crack plane is described by a smooth function of the radial coordinate. For two-dimensional stress profiles as well as for variable ratios of the cylinder wall thickness to the inner radius, a selective use of the solutions is recommended considering their specific features and validity ranges.
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Devin, Austin F., Aditya P. Kulkarni, Bradley S. Young, and William F. Baker. "Interrelation of Architectural Form and Wind Climate on the Wind Performance of Supertall Towers." In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.0369.
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<p>The architectural form of tall and supertall buildings is a fundamentally influential factor in the building’s wind response. Under the action of wind, a tower’s shape can significantly influence the building’s occupant comfort levels, serviceability performance, as well as the effective wind loads which a structure must resist. As tall buildings advance to ever-increasing heights and, more recently, unprecedented slenderness ratios, the across-wind response, or lift response, of towers due to vortex shedding becomes the predominant contributor to wind response. The frequency and intensity of vortex formation off a bluff body is a function of the shape and width of the bluff body, and the speed of the flow. This is a critical relationship in wind engineering where fluid dynamics and architecture intersect, and is defined by the powerful Strouhal equation [1]. This paper shall investigate wind response as a function of the interrelation of the Strouhal number parameters with the structure’s own dynamic properties, as well as the wind environment in which the building is located. In addition, the potential benefit of Critical Width and Critical Mean Recurrence Interval plots as initial indicators at the conceptual stage of tower design will be highlighted.</p>
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Harris, Salil, Aniruddha Sinha, and Sudarshan Kumar. "Model Order Identification of Combustion Instability Using Lipschitz Indices." In ASME 2019 Gas Turbine India Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gtindia2019-2694.
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Abstract Gas turbine combustors employing lean premixed combustion are prone to combustion instability. Combustion instability, if unchecked, will have deleterious effects to the combustor and hence needs to be controlled. Active control methods are preferred to obtain better off-design performance. The effectiveness of active control methods is dependent on the quality of controller which in-turn depends on the quality of model. In the present work, an input-output model structure, where the output of the system at the current instant is modelled as a nonlinear function of delayed inputs and outputs is chosen. As there are infinite possibilities for representation of nonlinear functions, all parameters in the model structure like time delay between input and output, number of delayed input and output terms and the appropriate form of nonlinear function can be obtained only iteratively. However, prior knowledge of delay and number of delayed inputs and outputs reduces the computational intensity. To this end, the present work utilizes the method of Lipschitz indices to obtain the number of delayed inputs and outputs.
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Park, Joel T., J. Michael Cutbirth, and Wesley H. Brewer. "Hydrodynamic Performance of the Large Cavitation Channel (LCC)." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45599.
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The U. S. Navy William B. Morgan Large Cavitation Channel (LCC) in Memphis, Tennessee, is the world’s largest water tunnel. Its hydrodynamic performance is outlined in this paper. Three key characteristics of tunnel velocity were measured: temporal stability, spatial uniformity, and turbulence. Temporal stability and spatial uniformity were measured by laser Doppler anemometer (LDA), while the turbulence was measured with a conical hot-film and constant temperature anemometer (CTA). The velocity stability at a single point for run times greater than 2 hours was measured as ±0.15% at the 95% confidence level for velocities from 0.5 to 18 m/s. The spatial non-uniformity for the axial velocity component was ±0.34 to ±0.60% for velocities from 3 to 16 m/s. The non-uniformity in the vertical velocity was nominally 2%. The turbulence or relative turbulence intensity, which is the commonly reported performance characteristic for water tunnels, was measured as 0.2 to 0.5% depending on tunnel velocity. Additional information includes calibration of the LDA and CTA, test section velocity as a function of pump speed, acceleration of the test section velocity, velocity spectra, and color contour plots of the axial and vertical components for velocity uniformity. The measurements demonstrate that the LCC is a high-quality world-class water tunnel.
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Corti, Enrico, Giorgio Mancini, Claudio Forte, and Davide Moro. "Automatic Combustion Phase Calibration With Extremum Seeking Approach." In ASME 2013 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icef2013-19132.
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Combustion control is assuming a crucial role in reducing engine tailpipe emissions and maximizing performance. The number of actuations influencing the combustion is increasing, and, as a consequence, the calibration of control parameters is becoming challenging. One of the most effective factors influencing performance and efficiency is the combustion phasing: for gasoline engines control variables such as Spark Advance (SA), Air-to-Fuel Ratio (AFR), Variable Valve Timing (VVT), Exhaust Gas Recirculation (EGR) are mostly used to set the combustion phasing. The optimal control setting can be chosen according to a target function (cost or merit function), taking into account performance indicators, such as Indicated Mean Effective Pressure (IMEP), Brake Specific Fuel Consumption (BSFC), pollutant emissions, or other indexes inherent to reliability issues, such as exhaust gas temperature, or knock intensity. Many different approaches can be used to reach the best calibration settings: Design Of Experiment (DOE) is a common option when many parameters influence the results, but other methodologies are in use: some of them are based on the knowledge of the controlled system behavior, by means of models that are identified during the calibration process. The paper proposes the use of a different concept, based on the extremum seeking approach. The main idea consists in changing the values of each control parameter at the same time, identifying its effect on the monitored target function, allowing to shift automatically the control setting towards the optimum solution throughout the calibration procedure. An original technique for the recognition of control parameters variations effect on the target function is introduced, based on spectral analysis. The methodology has been applied to data referring to different engines and operating conditions, using IMEP, exhaust temperature and knock intensity for the definition of the target function, and using SA and AFR as control variables. The approach proved to be efficient in reaching the optimum control setting, showing that the optimal setting can be achieved rapidly and consistently.
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Ren, Bing, Fujun Gan, Yu Dang, and Libing Zhu. "Numerical Simulation of Crud Effects on the Flow and Heat Transfer Performance in PWR 17×17 Rod Bundles." In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-66537.
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Corrosion products on fuel cladding surface have a significant impact on reactor operation. These types of deposits are defined as Corrosion Residual Unidentified Deposit (CRUD) and are consist of a porous matrix of nickel and iron based oxides deposited on the fuel cladding surface. It is well known that crud deposits may cause potential Crud Induced Localized Corrosion (CILC) risk and Crud Induced Power Shift (CIPS) risk. The paper presents a Computational Fluid Dynamic (CFD) method of predicting the crud effect on the thermal hydraulic performance. The effect of the crud roughness is mainly considered in the simulation, the flow near the wall of the crud is solved by modifying wall function in the prism layer. The simulation object is a span of typical 17×17 rod bundle with a mid grid in PWR, all the structures including grid straps, springs, dimples, mixing vanes and welding spots are included. Thicknesses of grid and fuel cladding are considered in order to precisely simulate the fluid-solid conjugate heat transfer. The crud is set to be covered on the full span downstream of the grid. The simulation is based on the CILC risk pre-analysis and the computed information in the mostly likely crud deposit position is used as boundary condition. Based on the simulation results, the crud effects on the flow characteristics including vortex structures, circulation, turbulent intensity and second flow intensity and the heat transfer characteristics including rod temperature, fluid temperature and heat transfer coefficient are discussed in detail.