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1
Ridd, Jennifer Elizabeth. "Fatigue performance of stay cables". Full-text Adobe Acrobat (PDF) file, 2004. http://www.engr.utexas.edu/research/fsel/FSEL_reports/Thesis/Ridd,%20Jennifer.pdf.
Testo completo
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Bean, Matthew James. "Bending fatigue performance of small-scale stay cables". Full-text Adobe Acrobat (PDF) file, 2006. http://www.engr.utexas.edu/research/fsel/FSEL_reports/Thesis/Bean,%20Matthew.pdf.
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Osiroff, Ricardo. "Damorheology: creep-fatigue interaction in composite materials". Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/38757.
Testo completoAbstract (sommario):
This investigation addresses the interaction mechanisms of time dependent material behavior and cyclic damage during fatigue loading of fiber reinforced composite laminates. A new term 'damorheology' has been coined to describe such physical behavior. The lamina has been chosen as the building block and a cross ply laminate configuration was the selected test case. The chosen material system is the Radel X/T65-42 thermoplastic composite by Amoco. The fatigue performance at the lamina level is represented by the dynamic stiffness, residual strength and fatigue life of unidirectional laminates. The time dependent behavior is represented at the lamina level by a Pseudo-Analog Mechanical model. The thermo-rheological characterization procedure combines mechanical (creep) and thermal (dynamic mechanical analysis) techniques.Ph. D.
4
Yang, Qi. "BIO-SIGNAL ANALYSIS IN FATIGUE AND CANCER RELATED FATIGUE: WEAKENING of CORTICOMUSCULAR FUNCTIONAL COUPLING". Cleveland, Ohio : Cleveland State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1213888265.
Testo completoAbstract (sommario):
Thesis (D.Eng.)--Cleveland State University, 2008.Abstract. Title from PDF t.p. (viewed on Oct. 8, 2008). Includes bibliographical references (p. 91-99). Available online via the OhioLINK ETD Center. Also available in print.
5
Wallström, Maria, e Nadia Axelsson. "Med fatigue som följeslagare : upplevelsen av att leva med MS-relaterad fatigue/trötthet". Thesis, Högskolan i Borås, Institutionen för Vårdvetenskap, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-18610.
Testo completoAbstract (sommario):
Multipel skleros, MS, är en neurologisk autoimmun sjukdom som drabbar centrala nervsystemet. Trötthet/fatigue upplevs av många som ett av de svåraste symptomen som inverkar starkt på det vardagliga livet. MS-relaterad fatigue/trötthet ger en känsla av utmattning och brist på energi som kan vara överväldigande. Tröttheten är orimlig i förhållande till de aktiviteter som utförs. Syftet med uppsatsen var att beskriva hur det är att leva med MS-relaterad fatigue/trötthet. Metoden som användes var litteraturstudie med kvalitativ innehållsanalys som baserats på åtta vetenskapliga artiklar. Dataanalysen skedde med hjälp av Fribergs (2006) beskrivning. Ur resultatet framkom fyra teman varav det första var upplevelsen av kroppen som ett fysiskt hinder. Detta tema belyser hur ett antal intervjupersoner upplever sin kropp som ett hinder och hur fatigue/trötthet begränsar och påverkar det dagliga livet. Tema två och tre beskriver hur relationer till familj och vänner kan förändras samt hur den psykiska hälsan påverkas. Det fjärde och sista temat handlar om hur personer som lever med denna trötthet lägger upp strategier och på bästa sätt planerar sin vardag för att orka mer. I diskussionen diskuteras begrepp som hälsa och sjukdom. Vi belyser också hur fysisk träning och annan självhjälp kan minska fatigue/trötthet och öka en människas psykiska hälsa. I de praktiska implikationerna tar vi upp vikten av information och kommunikation som vi anser är grunden till en god vårdrelation.Program: Sjuksköterskeutbildning
Uppsatsnivå: C
6
Heisinger, Aaron E. "Association between driver-reported sleep and predicted behavior of effectiveness based on the Fatigue Avoidance Scheduling Tool". Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Jun/09Jun%5FHeisinger.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2009.Thesis Advisor(s): Miller, Nita Lewis. "June 2009." Description based on title screen as viewed on July 10, 2009. Author(s) subject terms: Large truck crash, long-haul truck drivers, heavy truck operations, Large Truck Crash Causation Study, effects of fatigue on driver performance, long-haul operations, commercial transportation carriers, Federal Motor Carrier Safety Administration, National Highway Traffic Safety Administration. Includes bibliographical references (p. 35-37). Also available in print.
7
Jiang, Zhiguo. "Altered Cortico-cortical Brain Connectivity During Muscle Fatigue". Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1264108010.
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Lebeck, Matthew Victor. "Predictive methods applied to the vibratory response of machining structural steel and weldments". Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/16021.
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McKinnon, Peter Laurence, University of Western Sydney, College of Social and Health Sciences e of Nursing Family and Community Health School. "Tired of dying : fatigue and stress in long distance road transport". THESIS_CSHS_NFC_McKinnon_P.xml, 2004. http://handle.uws.edu.au:8081/1959.7/657.
Testo completoAbstract (sommario):
In this thesis, the author has drawn on a large body of international research and his own surveys, interviews and experience to examine the interrelated issues of Fatigue and Stress in the long distance sector of the Australian road transport industry. Two major Australian studies are studied in some detail: House of Representatives Standing Committee on Communications, Transport and the Arts: Beyond the Midnight Oil, Report into an Inquiry into Managing Fatigue in Transport, Parliament of the Commonwealth of Australia October 2000 (The Neville Report) and Quinlan, Michael, Report of an Inquiry into Safety in the Long Haul Sector of the Road Trucking Industry, Motor Accident Authority of NSW, Nov 2001 and the United States of America: Belzer, Michael H., Sweatshop on Wheels: Winners and Losers in Trucking Deregulation, Oxford University Press, New York, 2000, has direct relevance to this study, especially as it relates to the underlying causes of much of the fatigue and stress suffered by long distance drivers. An extensive literature review was undertaken to help form an understanding of the issues and developments relating to workplace fatigue and stress, in several different settings, including the military, aviation and general industry. The author has surveyed a number of long distance drivers and interviewed managers and others linked to this industry, analysed their responses and reported on the findings. Since the commencement of this study, several significant changes have occurred in the relevant legislation and its application, and where possible these have been incorporated into the studyMaster of Science (Hons)
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De, Gray Birch Casey. "The effects of sustained attention, workload and task-related fatigue on physiological measures and performance during a tracking task". Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1005198.
Testo completoAbstract (sommario):
Despite extensive research into the concept of mental fatigue there is as yet no “gold standard” definition or measurement technique available. Because of this a large amount of fatigue-related errors are still seen in the workplace. The complexity of the problem lies with the inability to directly measure mental processes as well as the various endogenous and exogenous factors that interact to produce the experienced fatigue. Fatigue has been divided into sleep-related and task-related fatigue; however the task-related aspect is evident both during normal waking hours as well as during periods of sleep deprivation, therefore this aspect is considered important in the understanding of fatigue in general. The concept of task-related fatigue has further been divided into active and passive fatigue states; however differentiation between the two requires careful consideration. Various physiological measures have been employed in an attempt to gain a better understanding of the mechanisms involved in the generation of fatigue, however often studies have produced dissociating results. The current study considered the task-related fatigue elicited by a tracking task requiring sustained attention, in order to evaluate the usefulness of various cardiovascular and oculomotor measures as indicators of fatigue. A secondary aim was to determine whether the behavioural and physiological parameter responses could be used to infer the type of fatigue incurred (i.e. an active versus passive fatigue state) as well as the energetical mechanisms involved during task performance. A simple driving simulator task was used as the main tracking task, requiring constant attention and concentration. This task was performed for approximately two hours. Three experimental groups (consisting of 14 subjects each) were used: a control group that performed the tracking task only, a group that performed a five minute auditory memory span task concurrently with the driving task after every 20 minutes of pure driving, and a group that performed a visual choice reaction task for five minutes following every 20 minute driving period. The secondary tasks were employed in order to evaluate the extent of resource allocation as well as arousal level. Performance measures included various driving performance parameters, as well as secondary task performance. Physiological measures included heart rate frequency (HR) and various time- and frequency-domain heart rate variability (HRV)parameters, pupil dilation, blink frequency and duration, fixations, and saccadic parameters as well as critical flicker fusion frequency (CFFF). The Borg CR-10 scale was used to evaluate subjective fatigue during the task, and the NASA-TLX was completed following the task. A decline in driving performance over time was supplemented by measures such as HR, HRV and pupil dilation indicating an increase in parasympathetic activity (or a reduction in arousal). An increase in blink frequency was considered as a sign of withdrawal of attentional resources over time. Longer and faster saccades were also evident over time, coupled with shorter fixations. With regards to the secondary task influence, the choice RT task did not affect any behavioural or physiological parameters, thereby contesting the active fatigue theory of resource depletion, as well as implying that the increase in demand for the same resources used by the primary task was insufficient to affect the state of the subjects. The increased load elicited by the memory span task improved driving performance and increased measures of HR, HRV, pupil dilation and blink frequency. Some of these measures produced opposite effects to what was expected; an attempt to explain the dissociation of the various physiological parameters was expressed in terms of arousal, effort and resource theories. Overall, the results indicate that the fatigue and/or reduced arousal accompanying a monotonous sustained attention task can, to some degree, be alleviated through intermittent performance of a secondary task engaging mental resources other than the ones used for the primary task. The degree to which such a task is beneficial, however, requires careful consideration as while an immediate increase in arousal and primary task performance is noted, the impact of the task on general attentional resources may be detrimental in the case of reacting should an emergency situation occur.
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Raikar, Sajal Vijay. "Cement Augmentation Enhanced Pullout Strength Of Fatigue Loaded Bone Screws". University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1226240822.
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Taylor, Kristie-Lee. "Monitoring neuromuscular fatigue in high performance athletes". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2012. https://ro.ecu.edu.au/theses/581.
Testo completoAbstract (sommario):
With improving professionalism of sports around the world, the volume and frequency of training required for competitive performances at the elite level has increased concurrently. With this amplification in training load comes an increased need to closely monitor the associated fatigue responses, since maximising the adaptive response to training is also reliant on avoiding the negative consequences of excessive fatigue. The rationale for the experimental chapters in this thesis was established after considering survey responses regarding current best practice for monitoring fatigue in high performance sporting environments (Chapter 3). On the basis of the results, vertical jump assessments were selected for further investigation regarding their utility in determining neuromuscular fatigue responses. Outcomes from the subsequent series of studies aimed to provide practitioners working in high performance sport with guidelines for using vertical jumps to monitor athletic fatigue.
The results from Chapter 4 indicate using the mean value of at least six jumps enhances the ability to detect small but practically important changes in performance from week to week. This study also highlighted large differences (4-6%) in morning and afternoon performance, indicating that the time of day performance is assessed needs to be accounted for when monitoring changes in jump performance. Chapter 5 explored the theory that the time of day effect observed in Chapter 4 can be explained by internal temperature differences. This theory was supported by demonstrating that an extended warm-up period can negate differences in jump performance in the morning and the afternoon. Researchers who are unable to standardise the time of day that assessment occurs are able, therefore, to control for performance differences by manipulating the warm-up protocols.
The third study examined changes in vertical jump performance over a three month training period and produced several novel outcomes. A major finding was that unloaded jumps were more sensitive to neuromuscular fatigue during intensive training than loaded jumps (Chapter 6). Furthermore, this set of results showed that all subjects changed their jump technique via a reduction in the amplitude of the countermovement when they were highly fatigued. Using the same data, an analysis was performed to quantify individual differences in within-subject variation (Chapter 7) during normal and intensive training. These results provided the first indication that within-subject variability in vertical jump performance is substantially different between individuals and between different training phases, an important consideration for interpreting the practical importance of performance changes.
In Chapter 8 the relationship between vertical jump performance and electrically elicited force of the knee extensors was examined to better understand the mechanism(s) of changes in jump performance associated with neuromuscular fatigue during intensive overload training. The results showed that the fatigue assessed by vertical jump performance was likely not only peripheral in origin as previously suggested by other authors. Further research is required to further understand the mechanisms of reduced performance during overload training, although the preliminary evidence presented implicates central mechanisms. To conclude the thesis, the findings presented in the experimental chapters are summarised, with a series of practical recommendations for using vertical jumps to monitor athletic fatigue presented.
13
Hart, Timothy C. "Respondent fatigue in self-report victim surveys : examining a source of nonsampling error from three perspectives". [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001456.
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Ranganathan, Kannan. "A simulation model for stress measurements in notched test specimens by x-ray diffraction". Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45887.
Testo completoAbstract (sommario):
An analytical model was developed to simulate the stress state of notched tensile specimens. Actual experiments are being carried out by other investigators to study the relaxation of residual stresses in specimens containing stress raisers. In the present work, the stress state developed in notched tensile specimens was assessed by determining the response of the stress state in the form of x-ray line profiles; this is useful in the understanding and measurement of effects due to such stress states obtained in actual experiments. The theoretical relationship between the stress gradient and the depth of penetration of the x-ray beam at the edge of a notch tensile specimen was also studied. In addition, the effect of changes in the radius of curvature of the notch-tip on errors in measured stress values is also considered. Furthermore, a description of the state-of-the-art x-ray system being used in the experimental work is also included.
Master of Science
15
Blumoff, Sonja. "Oxygen Uptake Kinetics in Severe Intensity Exercise". Thesis, University of North Texas, 2000. https://digital.library.unt.edu/ark:/67531/metadc2539/.
Testo completoAbstract (sommario):
The purpose of this study was to describe mathematically the oxygen uptake kinetics during cycle ergometry, and to examine the effect of intensity on the kinetic responses within the severe domain. Sixteen volunteers performed a series of exercise tests at a range of intensities selected to elicit fatigue in ~3 to 10 min. A simple mono-exponential model effectively described the response across all intensities. There was a positive correlation between the response time and the time to fatigue, demonstrating that the maximal oxygen uptake was achieved faster at higher intensities within the severe domain. Models incorporating two components effectively described the responses only in tests lasting 8 min or more. It was concluded that there is a second, slow component in the oxygen uptake response only at the lower intensities within the severe domain.
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Costantini, Oren. "SERRATUS ANTERIOR MUSCLE FATIGUE EFFECTS ON SCAPULAR KINEMATICS". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1325219873.
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Benini, Brian J. "Tension and Flex Fatigue Behavior of Small Diameter Wires for Biomedical Applications". Cleveland, Ohio : Case Western Reserve University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1269970809.
Testo completoAbstract (sommario):
Thesis (Master of Sciences)--Case Western Reserve University, 2010Department of Materials Science and Engineering Title from PDF (viewed on 2010-05-25) Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center
18
Van, Kessel Kirsten. "The Development and efficacy of cognitive behaviour therapy for multiple sclerosis fatigue: a randomised controlled trial". Thesis, University of Auckland, 2007. http://hdl.handle.net/2292/3313.
Testo completoAbstract (sommario):
Aim Multiple Sclerosis (MS) is an unpredictable demyelinating disease of the central nervous system (CNS), with fatigue being one of the least understood symptoms. Based on a systematic review of the literature, a cognitive behavioural model of MS fatigue was developed and used to design a manualised eight session cognitive behaviour therapy (CBT) intervention to treat MS fatigue. The purpose of the randomized controlled trial (RCT) was to investigate the efficacy of CBT compared to relaxation training (RT) to treat fatigue in MS. Methods Seventy-two patients with MS fatigue were randomly assigned to either eight sessions of CBT or eight sessions of RT, designed to control for therapist time and attention. Participants were assessed before and after treatment, and at three and six months follow-up. Primary outcomes included the Fatigue Questionnaire (FQ) and the Clinical Global Impression Scale (CGIS). Secondary outcomes included measures of fatigue related impairment, mood, stress, sleep problems and daytime sleepiness. Seventy of the 72 participants completed all therapy sessions and 69 participants completed all assessments. Results Analyses were carried out by intention-to-heat. There was a significant group by time interaction for fatigue, indicating that the CBT group had significantly greater reductions in fatigue severity than the RT group (p<.02). A-priori contrasts showed that this significant effect was largely accounted for by changes between baseline and end of treatment (P<.00). By six month follow-up improvement in fatigue was equivalent in both groups. The key mechanism of improvement in fatigue severity during CBT was a positive change in schematic beliefs about fatigue. At the end of treatment 88.6% of the CBT group rated themselves as improved compared to 73% of the RT group, but this difference was not significant (p<.09). Both groups improved on almost all secondary outcomes, with the CBT participants improving more significantly on depression, anxiety and stress between baseline and end of treatment (p<.05). Conclusions CBT appears to be an effective treatment for MS fatigue, with CBT participants improving significantly more on fatigue than RT participants between baseline and end of treatment. Obtained effect sizes for fatigue in both CBT and RT were considerably larger than those in previous controlled trials of pharmacological and non-pharmacological interventions. Both groups improved on almost all of the secondary outcomes. Findings support the relevance of a cognitive behavioural model for MS fatigue.Whole document restricted, but available by request, use the feedback form to request access.
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Ollison, Jacquelyn. "Improving Teacher Retention by Addressing Teachers' Compassion Fatigue". Scholarly Commons, 2019. https://scholarlycommons.pacific.edu/uop_etds/3602.
Testo completoAbstract (sommario):
California is experiencing a massive teacher shortage, and urban schools are disproportionately affected by it negatively. Retention efforts to date have not included strategies to address Compassion Fatigue (burnout and secondary trauma) teachers experience when working with traumatized students at urban schools. This dissertation explores whether Compassion Fatigue is an unaddressed reason for teacher attrition at urban schools. A mixed method practical action research approach using the Professional Quality of Life Scale Version Five (ProQOL 5) and qualitative interviews, portions of which were turned into illustrative vignettes drove the exploration. Approximately 114 teachers completed the ProQOL 5. Statistical analysis of the ProQOL 5 results showed that female teachers experience more compassion fatigue than male teachers; compassion fatigue is more acute with beginning teachers than with veteran teachers; and that teachers working at high-poverty schools experience statistically significant differences in compassion satisfaction and fatigue than teachers at low poverty schools. Correlation tests revealed statistically significant relationships between compassion fatigue and the school’s racial demographics even when controlling for the socioeconomically disadvantaged status of the school and teacher ethnicity. Linear regression models showed that the percentage of African American students in the school is a statistically significant predictor of compassion fatigue. Qualitative interview analysis showed that secondary trauma from students is not the only trauma teachers are experiencing, and that school climate and conditions matter when attempting to retain teachers. In the final phase of the action research, a policy brief was developed through a collaborative and iterative process, based both on the findings and engagement with stakeholders. If California is serious about producing and retaining high-quality teachers at all urban schools,’ efforts to mitigate compassion fatigue should be undertaken immediately.
20
O'Brien, Christine Jane. "Exercise Participation in Parkinson's Disease: A Qualitative Study". Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/11685.
Testo completoAbstract (sommario):
Exercise and physiotherapy improve mobility and health-related quality of life in people with Parkinson’s disease (PD) and exercise is now an important component of disease management. People may live with PD for many years and to maximise the benefits of exercise, individuals need to participate in exercise regularly. People with PD have a range of motor and non-motor impairments that could impact on exercise participation but there is limited evidence about the factors that influence exercise participation in this population. It is important for physiotherapists to understand these factors so that exercise programs can be developed to encourage uptake and sustain participation. A qualitative study explored the experience of 8 participants who were variously successful in a semi-supervised, 6-month falls prevention exercise program. The aim was to understand the participants’ meaning of exercise and how factors influencing exercise participation interact and impact on decisions made about whether to exercise or not. In-depth semi-structured interviews were conducted and analyzed using grounded theory methodology. It was found that, for this group, exercise participation assisted in reframing identity as individuals are faced with losses associated with ageing and PD. Three new influences on exercise participation were identified: the non-motor impairments of apathy and fatigue, a belief in a finite energy quota, and the importance of feedback. Decisions about whether to exercise were the result of a dynamic process of evaluation by the participants in which goals were crucial. A model was developed to explain the interaction of factors involved in making decisions regarding exercise participation. This thesis contains information on how individual factors interact and influence exercise participation in these individuals with PD, suggestions on how to address these in the clinical setting and offers directions for further research.
21
Barahona, Jose L. "Maquiladoras in Central America: An Analysis of Workforce Schedule, Productivity and Fatigue". TopSCHOLAR®, 2019. https://digitalcommons.wku.edu/theses/3146.
Testo completoAbstract (sommario):
Textile factories or Maquiladoras are very abundant and predominant in Central American economies. However, they all do not have the same standardized work schedule or routines. Most of the Maquiladoras only follow schedules and regulations established by the current labor laws without taking into consideration many variables within their organization that could affect their overall performance. As a result, the purpose of the study is to analyze the current working structure of a textile Maquiladora and determine the most suitable schedule that will abide with the current working structure but also increase production levels, employee morale and decrease employee fatigue.
A Maquiladora located in el Salvador, C.A. has been chosen for the study. It currently provides finished goods to one of the leading textile industries in the United States of America. The study will consist of collecting production numbers for two of their manufacturing cells for five consecutive days. In addition, a questionnaire will be administered to measure employee fatigue. Once all data have been collected, the data will be analyzed to determine the best working structure that will benefit the employee and the employer.
22
Lindauer, Jason M. "F/A-18(A-D) wing root Fatigue Life Expended (FLE) prediction without the use of strain gage data". Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Jun/10Jun%5FLindauer.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2010.Thesis Advisor(s): Buttrey, Samuel E. ; Second Reader: Whitaker, Lyn R. "June 2010." Description based on title screen as viewed on July 15, 2010. Author(s) subject terms: F/A-18, fatigue life expended (FLE), linear regression, Naval Air Systems Command (NAVAIR), prediction, S-Plus, strain gage, wing root fatigue. Includes bibliographical references (p. 53). Also available in print.
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Moore, Emily. "The Frequency, Aqueous Solution, Stress Amplitude,Temperature (FAST) Machine: A Device Proposed for Accelerated Fatigue Testing of Cortical Bone". Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1339170465.
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Vandermey, Nancy E. "Damage development under compression-compression fatigue loading in a stitched uniwoven graphite/epoxy composite material". Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10242009-020345/.
Testo completoAbstract (sommario):
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991.Vita. Abstract. Includes bibliographical references (leaves 111-113). 1 folded diaghram included. Also available via the Internet.
25
Metwali, Mahmoud. "Motor variability, task performance, and muscle fatigue during training of a repetitive lifting task: adapting motor learning topics to occupational ergonomics research". Diss., University of Iowa, 2019. https://ir.uiowa.edu/etd/6803.
Testo completoAbstract (sommario):
Low back problems are among the most common nonfatal occupational injuries reported in the United States, and account for substantial healthcare expenditures (e.g., medical care costs) and losses to worker productivity. A strong association has been well-documented between occupational exposure to repetitive trunk motion and low back problems, particularly among workers performing manual material handling (i.e., lifting) activities. A feature of repetitive motion believed important to the development of work-related musculoskeletal disorders (MSDs), including low back problems, is a lack of within-individual, between-cycle variation of physical exposure summary measures, e.g., when observed visually, the cycle-to-cycle motion pattern appears consistent. An active literature has emerged using concepts of motor control to improve ergonomists’ understanding of physical exposure variation (i.e., motor variability) arising from individual-level mechanisms during repetitive work.
Fundamentally, for any particular individual, the onset of exposure to a repetitive physical activity (i.e., task training) involves a learning process during which motor control strategies are developed to accomplish the task effectively. The cycle-to-cycle variability of motor learning metrics, such as postural and task performance summary measures, has been observed to exponentially decay during task training. From an ergonomics perspective, a temporal reduction in postural variability may lead to greater cumulative loading and physiological fatiguing of the underlying muscle tissues (due to more consistent cycle-to-cycle movements), thus increasing MSD risk over time. However, it is not known if, or to what extent, physical task characteristics (e.g., work pace) modify the temporal behavior of motor variability during training of a repetitive occupational activity. Moreover, the relationships between motor variability, task performance, and muscle fatigue during occupational task training are not well understood.
The goal of this dissertation was to present new information concerning occupationally relevant metrics of motor learning during training of a laboratory-simulated, repetitive lifting activity. In this study, participants performed 100 repetitions (i.e., cycles) of the lifting task in each of four experimental sessions (i.e., visits) at different combinations of box load (low or high) and work pace (slow or fast). Three main observations were discussed in this dissertation: (i) participants exhibited a greater temporal reduction in the cycle-to-cycle variability of trunk postural summary measures during training of a heavier-weighted and faster-paced lifting activity (Chapter 3), which may have facilitated increases in the efficiency and repeatability of box movements (Chapter 4), (ii) the cycle-to-cycle variability of the erector spinae (back) muscle activity summary measures increased, but the variability of the multifidus muscle activity summary measures decreased, over time during faster-paced lifting (Chapter 3), and (iii) a greater temporal increase in trunk postural variability (i.e., a more “flexible” trunk movement strategy) was generally associated with lesser electromyographic back muscle fatigue during training of the lifting task (Chapter 5). Collectively, these research findings may open pathways to the development of new task design criteria and ergonomic guidelines to promote motor variability in the workplace and, ultimately, improve workers’ musculoskeletal health.
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Reeves, Audrey Michelle. "Compassion Fatigue: Stories/Artworks of an Art Teacher with a Trauma-Informed Pedagogy". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555570912535465.
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Dickson, Trudi. "Investigating physical activity and associations with sleep, fatigue and mood after breast cancer treatment : an exploratory study and clinical research portfolio". Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3617/.
Testo completoAbstract (sommario):
Objective: Physical activity has been shown to improve sleep, fatigue and mood among breast cancer patients during treatment. However, few studies have focused on assessing the effect of activity on these symptoms after treatment is complete. Using a correlational design, this study aimed to explore associations between physical activity, sleep, fatigue and mood in women who had completed treatment for breast cancer and to evaluate the reliability and validity of the short-version International Physical Activity Questionnaire. Methods: Twenty-eight women (aged 43 to 75 years) with stage I and II breast cancer were recruited at 6-months post-diagnosis and after completion of active treatment. Respondents completed measures of activity, sleep, fatigue, depression and anxiety. Six participants also undertook actigraphic monitoring to obtain objective activity levels. Results: Descriptive analyses suggest the sample was relatively active with 50% of participants engaging in moderate-intensity activities. Despite this, however, only 18% were sufficiently active to meet national guidelines. No significant relationships were found between total physical activity, sleep, fatigue or depression, whereas, anxiety and activity were significantly correlated. Reliability of the IPAQ was low, however, comparison with objective actigraphy data suggests high criterion validity. Conclusion: These findings have implications for designing interventions to reduce anxiety among breast cancer patients returning to physical activity after treatment. However, the choice of assessment instrument may have a significant impact on research results.
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O'Connor, Maureen J. Patillo Paul J. "Reengineering human performance and fatigue research through use of physiological monitoring devices, web-based and mobile device data collection methods, and integrated data storage techniques /". Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FO'Connor.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, December 2003.Thesis advisor(s): Nita L. Miller, Thomas J. Housel. Includes bibliographical references (p. 115-117). Also available online.
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Cassidy, Christopher. "A Comparison of Fatigue during Cardiocerebral Resuscitation with Different Compression Rates Among Layperson and Professional Rescuers". DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1299.
Testo completoAbstract (sommario):
Quality chest compressions during Cardiopulmonary Resuscitation (CPR) are vital to maintaining adequate perfusion of oxygenated blood to the organs of the body to sustain life. Over the years, the compression rate recommended in Basic Life Support (BLS)/ Advanced Cardiac Life Support (ACLS) protocols for the best possible outcome has risen, and with that increase there are questions regarding rescuer fatigue and the effectiveness of compressions. Layperson and professional rescuers, answering to an emergency, both maintain continuous chest compressions until advanced life support arrives. Depending on the location, this arrival time would most likely be longer than the two minute standard time given to rotate rescuers before fatigue compromises performance. The objective of this research was to investigate the level of rescuer fatigue associated with continuous compressions, varying compression rates, physical fitness, gender, and among layperson versus professional rescuers.
Sixty-one participants performed uninterrupted chest compressions on a manikin for 15 minutes. Before performing compressions, physical fitness was evaluated using a YMCA bench press for an assessment of upper body strength/endurance and a 3-minute step test to evaluate aerobic fitness. Subjects performed two trials at compression rates of greater or equal to 80 and greater or equal to 100 per minute with a 5-minute rest between trials.
Male professional rescuers had a greater strength/endurance, and thus were able to perform compressions for a longer period of time compared to their female counterparts. Compression duration and the YMCA Bench Press test score were significantly correlated (p = .0135). Cardiocerebral Resuscitation providers should maintain an adequate upper body strength, particularly if they may be required to perform continuous chest compressions at high rates for more than a few minutes.
30
Patillo, Paul L., e Maureen J. O'Connor. "Reengineering human performance and fatigue research through use of physiological monitoring devices, web-based and mobile device data collection methods, and integrated data storage techniques". Thesis, Monterey, California. Naval Postgraduate School, 2003. http://hdl.handle.net/10945/6156.
Testo completoAbstract (sommario):
Approved for public release; distribution is unlimitedIn the field of human research, particularly in operational environments, data collection techniques are difficult. Researchers often focus their efforts on the data analysis and overlook the shortcomings of their data collection and storage methodologies. In order to demonstrate effective data collection and storage methodology in a representative human research process, the process used by human fatigue and performance researchers at the Human Systems Integration Lab at Naval Postgraduate School (NPS) served as a Proof of Concept. Most recent studies conducted at NPS provided a model of the current process. The Knowledge Value Added (KVA) methodology was used as a tool of comparison of the current process to the reengineered process. Information technologies including wireless physiological monitoring devices, web-based and mobile device data collection methods, and integrated data storage techniques were incorporated in the reengineering effort. The data storage process included the design of a standard relational database format allowing research teams to easily access their data. This repository also enables data to be archived for future use (e.g., meta-analyses). To demonstrate the reengineered process in an operational environment, a field fatigue study was conducted at the Naval Officer Indoctrination School (OIS) in Newport, Rhode Island.
31
Dominguese, David J. "A Single Session of Repeated Wingate Anaerobic Test Caused Alterations in Peak Ground Reaction Force During Drop Landings". Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1268328477.
Testo completo
32
Buckenmeyer, Laura. "Optimization of Pedicle Screw Depth in the Lumbar Spine: Biomechanical Characterization of Screw Stability and Pullout Strength". University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365099627.
Testo completo
33
Kuruvilla, Mithun. "An Understanding of the Quasi-static Behavior, High Cycle Fatigue and Final Fracture Behavior of a Titanium (Ti- 4 Al-2.5 V-1.5 Fe-0.25 O2) Alloy". University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1217436482.
Testo completo
34
Dahlström, Örjan. "Focus on Chronic Disease through Different Lenses of Expertise : Towards Implementation of Patient-Focused Decision Support Preventing Disability: The Example of Early Rheumatoid Arthritis". Doctoral thesis, Linköpings universitet, Institutionen för beteendevetenskap och lärande, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-18112.
Testo completoAbstract (sommario):
Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disease. Treatment strategies emphasize early multi-professional interventions to reduce disease activity and to prevent disability, but there is a lack of knowledge on how optimal treatment can be provided to each individual patient. Aim: To elucidate how clinical manifestations of early RA are associated to disease and disability outcomes, to strive for greater potential to establish prognosis in early RA, and to facilitate implementation of decision support through analyses of the decision-making environment in chronic care. Methods: Multivariate statistics and mathematical modelling, as well as field observations and focus group interviews. Results: Decision support: A prognostic tree that predicted patients with a poor prognosis (moderate or high levels of DAS-28) at one year after diagnosis had a performance of 25% sensitivity, 90% specificity and a positive predictive value of 76%. Implementation of a decision support application at a rheumatology unit should include taking into account incentive structures, workflow and awareness, as well as informal communication structures. Prognosis: A considerable part of the variance in disease activity at one year after diagnosis could be explained by disease progression during the first three months after diagnosis. Using different types of knowledge – different expertise – prior to standardized data mining methods was found to be a promising when mining (clinical) data for new patterns that elicit new knowledge. Disease and disability: Women report more fatigue than men in early RA, although the difference is not consistently significant. Fatigue in early RA is closely and rather consistently related to disease activity, pain and activity limitation, as well as to mental health and sleep disturbance. Conclusion: A decision tree was designed to identify patients at risk of poor prognosis at one year after the diagnosis of RA. When constructing prediction rules for good or poor prognosis, including more measures of disease and disability progressions showed promise. Using different types of knowledge – different lenses of expertise – prior to standardized data mining methods was also a promising method when mining (clinical) data for new patterns that elicit new knowledge.Introduktion: Reumatoid artrit (RA) är en kronisk inflammatorisk sjukdom. Dagens behandlingsstrategi bygger på tidiga multiprofessionella insatser för att reducera sjukdomsaktivitet och minska risken för framtida funktionshinder. Idag finns stora datamängder tillgängliga gällande medicinering och utfall vid RA. Dessa data erbjuder möjligheter att generera ny kunskap som kan användas för att forma beslutsstöd. Syfte: Att undersöka hur olika kliniska manifestationer vid tidig RA samvarierar med funktionshinder och sjukdomsaktivitet, att pröva metoder att ställa prognos vid tidig RA, och att analysera en kontext för beslutsfattande inom vård av kroniskt sjuka. Metod: Multivariat statistik och matematisk modellering, samt observationsstudier och fokusgruppsintervjuer. Resultat: Beslutsstöd: Ett beslutsträd utformades för att bestämma vilka patienter som har dålig prognos (måttlig eller hög DAS-28) ett år efter diagnos. Beslutsträdet hade 25 % sensitivitet, 90 % specificitet och ett positivt prediktivt värde på 76 %. Vid införande av beslutsstöd på en reumatologisk klinik befanns det nödvändigt att hänsyn tas till incitamentsstrukturer, arbetsflöde och samarbetsformer. Informella kommunikationsstrukturer kan också ha stort inflytande på klinisk praxis. Prognos: En betydande del av variansen i sjukdomsaktivitet ett år efter diagnos kan förklaras av sjukdomsprogression första tre månaderna efter diagnos. Att formalisera olika experters erfarenheter före standardiserade ”data mining” metoder är en lovande ansats när man letar efter mönster i (kliniska) databaser. Funktionshinder och sjukdomsaktivitet: Kvinnor rapporterar mer trötthet än män vid tidig RA, men skillnaden är inte konsistent över tid. Trötthet vid tidig RA är nära relaterat till sjukdomsaktivitet, smärta och aktivitets begränsningar, men också till mental hälsa och sömnstörningar. Slutsats: Ett beslutsträd har utformats för att predicera patienter med dålig prognos inom tidig RA. Studier av fler mått på sjukdoms- och funktionshindersprogression behövs vid konstruktion av prediktionsregler för god eller dålig prognos framledes. Att använda sig av kunskap från olika experter – olika experters glasögon – vid sökandet efter mönster i stora datamängder för att generera ny kunskap är en lovande metodik. Implementering av beslutsstöd bör göras under övervägande av incitamentsstrukturer, arbetsflöde och samarbetsformer.
35
Ardatov, Oleg. "Apatinių galūnių įtvarų ilgaamžiškumo tyrimas". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120726_163924-05619.
Testo completoAbstract (sommario):
Baigiamajame magistro darbe yra atliekamas apatinių galūnių įtvarų ilgaamžiškumo tyrimas. Yra iškeliama čiurnos sąnario įtvarų patvarumo problema ir sudaroma jos sprendimo metodika. Darbe yra atliekama čiurnos sąnario biomechanikos analizė, įtvarų konstrukcijų ir medžiagų analizė, nagrinėjama ilgaamžiškumo reikšmė ir tyrimo būdai. Sudaroma tyrimo metodika. Kompiuterinio modeliavimo būdu, panaudojant SolidWorks programinę įrangą, yra sudaromas įtvaro modelis, nustatomos veikiančios apkrovos, atliekami įtempių ir poslinkių pasiskirstymo tyrimai. Atliekami modelio nuovargio bandymai. Atsižvelgiant į tyrimų rezultatus, yra sudaromi įtvarų iš aukštos temperatūros plastikų tinkamo pritaikymo nurodymai. Pateikiamos išvados ir literatūros sąrašas.Final thesis presents the research of durability of lower limbs splints. The problem of fatigue behaviour of ankle joint splint is raised and its solution is suggested. Final thesis contains ankle joint biomechanics analysis, lower limbs splints design and material analysis. Review of durability research methods is also done. The methodology of research is arranged. Using the computer aided modeling with SolidWorks software the model of ankle joint splint is created. Load parameters are determined, research of stresses and deformations are performed. Fatigue test is also performed. Due to the results of research, the instructions for ankle joint splints made of high density polyethylene and polypropylene use and adaptation are listed. Final thesis also contains conclusions and list of literature. Size of work – 77 pages of text without attachments, 55 pictures, 9 tables and 25 bibliographical sources.
36
Mealor, Andrew D. "Conscious and unconscious : passing judgment". Thesis, University of Sussex, 2013. http://sro.sussex.ac.uk/id/eprint/45262/.
Testo completoAbstract (sommario):
The extent to which conscious and unconscious mental processes contribute to our experiences of learning and the subsequent knowledge has been subject to great debate. Dual process theories of implicit learning and recognition memory bear many resemblances, but there are also important differences. This thesis uses subjective measures of awareness to explore these themes using the artificial grammar learning (AGL) and remember/know (R/K) procedures. Firstly, the relationship between response times associated with intuition and familiarity based responding (conscious judgment of unconscious structural knowledge) compared to rule and recollection based responding (conscious structural knowledge) in AGL were found to be strikingly similar to remembering and knowing; their R/K analogues. However, guessing (unconscious judgment knowledge) was also distinct from intuition and familiarity based responding. Secondly, implicit learning in AGL was shown to occur at test, which would not be expected in R/K. Finally, wider theories of cognition, unconscious thought and verbal overshadowing, were shown to have measurable effects on AGL and R/K respectively. The approach used in this thesis shows the merits of both in-depth analysis within a given method combined with the synthesis of seemingly disparate theories. This thesis has built upon the important distinction between conscious and unconscious structural knowledge but also suggests the conscious-unconscious division for judgment knowledge may be as important. Implicit learning and recognition memory tasks differ in the kinds of mental processes that subjective measures are sensitive toward; particularly so in situations where judgment knowledge is unconscious. Different theories and methods divide nature in different ways; the conscious-unconscious judgment distinction may prove an important one.
37
Soal, Keith Ian. "Vibration response of the polar supply and research vessel the S. A. Agulhas II in Antarctica and the Southern ocean". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/96058.
Testo completoAbstract (sommario):
Thesis (MEng) -- Stellenbosch University, 2014.ENGLISH ABSTRACT: Full scale measurements were conducted on the polar supply and research vessel the S.A. Agulhas II during a 78 day voyage from Cape Town to Antarctica in 2013/2014. Investigations were conducted into the effect of vibration on human comfort and the structural dynamic response of the vessel. Vibration measured in the bridge of the vessel is found to have little effect on human comfort for a standing person and is classified as not uncomfortable according to BS ISO 2631-1. Structural fatigue as a result of vibration is found to reach levels where damage is possible in the stern and where damage is probable in the bow during open water navigation, according to ship vibration guidelines by Germanischer Lloyd. Multivariate statistical analyses are performed to investigate the relationships between multiple predictor variables and vibration response. Factor analysis revealed data structure from which specific physical phenomena could be identified. Multivariable linear regression models are developed to predict vibration response and are found to provide more accurate predictions in open water than in ice. The 2-node, 3-node and 4-node normal bending modes of the structure are identified using operational modal analysis while the vessel was moored in the harbour. The natural frequencies, damping ratios and mode shapes are estimated and compared using LMS Operational PolyMAX and ARTeMIS CCSSI. A comparison of operational modal analysis results to the STX Finland finite element model show that the vessel’s modes occur at lower frequencies than numerically predicted. Clear potential is identified to further investigate structural vibration and operational modal analysis algorithm development in future research.
AFRIKAANSE OPSOMMING: Volskaal metings was op die poolvoorsienings en navorsingskip die S.A. Agulhas II uitgevoer tydens ’n 78 dae reis van Kaapstad tot Antarktika in 2013/2014. Ondersoeke is uitgevoer met betrekking tot die effek van vibrasie op menslike gemak en die strukturele dinamiese reaksie van die vaartuig. Vibrasie wat in die brug van die skip gemeet is, het min invloed op menslike gemak vir ’n staande persoon en word geklassifiseer as nie ongemaklik volgens BS ISO 2631-1. Strukturele vermoeidheid as gevolg van vibrasie bereik vlakke waar skade moontlik is in die spieël en waar skade waarskynlik is in die boog tydens navigasie in oop water, volgens skip vibrasie riglyne deur Germanischer Lloyd. Meerveranderlike statistiese ontledings is uitgevoer om die verhoudings tussen verskeie voorspellerveranderlikes en vibrasieterugvoer te ondersoek. Faktorontleding het data struktuur openbaar waaruit spesifieke fisiese verskynsels geïdentifiseer kan word. Multi-veranderlike lineêre regressiemodelle was ontwikkel om vibrasie reaksie te voorspel en lewer meer akkurate voorspellings in oop water as in ys. Die 2-nodus, 3-nodus en 4-nodus normale buig modes van die struktuur is geïdentifiseer met behulp van operasionele modale analise terwyl die skip vasgemeer in die hawe is. Die natuurlike frekwensie, demping verhoudings en mode vorms is beraam en vergelyk met behulp van LMS operasionele Polymax en ARTeMIS CCSSI. ’n vergelyking van operasionele modale analise resultate en ’n STX Finland eindige element model toon dat die vaartuig se modusse voorkom by laer frekwensies as wat numeries voorspel word. Duidelike potensiaal is geïdentifiseer om strukturele vibrasie en die ontwikkeling van operasionele modale analise algoritmes te ondersoek in toekomstige navorsing.
38
Liang, Yun-Ling, e 梁筠翎. "Research on Pilot Fatigue". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/44348655629265967282.
Testo completoAbstract (sommario):
碩士國立臺灣大學
土木工程學研究所
94
Pilot fatigue plays an important role in the flight safety. Except for the flight schedule, work hours and flying time may be other factors to lead to the fatigue. Actually, one of the important factors of that is the condition at work and rest period. For this reason, this study not only considers the cause, influence and countermeasures of pilot fatigue but also combines the different opinion of interview with pilots. After summarizing different kinds of studies, the goal of this study considers the condition at the work and rest period to analyze the issues of pilot fatigue. The rest order in the duty is always decided by the captain. But the crewmembers have the different physiology condition and the different fatigue feelings. This study considers the diverse factors such as the duty time, the pre-duty sleep time, the quality of sleep and so on. This analysis attempts to use the characteristics of work and rest period to establish a set of napping probability model with Logistic Regression Model and Gray System Theory. By this way, pilot could use this model to predict the probability of nap at different time range of duty. Hence, based on the objective standard, they could arrange the order of rest in the duty to reduce the fatal influence from fatigue. In order to provide pilot an easy, convenient and practical rest order suggestion, this study establishs a web about pilot fatige. Before being at the duty time, pilot could use it to obtain objective rest order to reduce the influence of fatigue, and then it provides a better and safer flight.
39
Feng, Wei Wen, e 馮蔚文. "Research on Fatigue and Leakage of Ferroelectric Capacitor". Thesis, 1996. http://ndltd.ncl.edu.tw/handle/69857991457460711431.
Testo completo
40
Elmaraghi, Omar A. "Integrated multibody dynamics and fatigue models for predicting the fatigue life of poly-V ribbed belts". Thesis, 2013. http://hdl.handle.net/1805/3691.
Testo completoAbstract (sommario):
Indiana University-Purdue University Indianapolis (IUPUI)Belt-drives are used in many applications such as industrial machines, washing machines, and accessory drives for automobiles and other vehicles. Multibody dynamics/finite element numerical models have become an effective way to predict the dynamic response of belt-drives. In this thesis, a high fidelity numerical model was built using a multibody dynamics/finite element code to simulate a belt-drive. The belt-drive transmits power from a turbine of a Rankin cycle (that uses the exhaust waste heat of the internal combustion engine as heat source) to the crank shaft of the engine. The code uses a time-accurate explicit numerical integration technique to solve the multibody dynamics differential equations. The belt was modeled using three-node beam elements to account for the belt axial and bending stiffness/damping, while the pulleys, shafts and tensioner body were modeled as rigid bodies. The penalty technique was used to model normal contact between the belt and the pulleys. An asperity-based friction model was used to approximate Coulomb friction between the belt and the pulleys. The dynamic response predicted using the model was validated by comparing it to experimental results supplied by Cummins Inc. A parameter sensitivity study was performed to evaluate the change in response due to change in various belt-drive parameters. A fatigue model was developed to predict the belt fatigue life using output from the explicit finite element code including normal and tangential forces between the belt and the pulleys and belt tension. The belt fatigue life was evaluated for alternative belt-drive configurations in order to find the configuration with the longest life.
41
HORNG-YITH, LIOU, e 劉宏毅. "Analysis and Research of Metal Fatigue Under Random Loading". Thesis, 1998. http://ndltd.ncl.edu.tw/handle/72925281993635328261.
Testo completoAbstract (sommario):
博士國立臺灣大學
機械工程學研究所
87
Some problems related to the metallic fatigue under random loading are studied in the present dissertation. The content of the dissertation is divided into two major parts. The first part focuses on the derivation of mathematical formulas that can be used for the prediction of fatigue damage and fatigue life of a component under random loading. The second part investigates the randomness of the parameters, which result in the scatter of the fatigue crack growth curves. In the first part of the dissertation, a key mathematical formula is derived based on random vibration theory in which Morrow*s nonlinear damage rule and the traditional S-N curve concept are both taken into consideration. Lambert*s empirical assumption or Gumbel*s asymptotic theory of statistical extremes is used to determine the maximum stress needed in applying the key mathematical formula. Computational algorithms for the prediction of fatigue damage and fatigue life under random for the prediction of fatigue damage and fatigue life under random loading are proposed and their accuracy is verified by the experimental data of 7075-T651 aluminum alloy. The following conclusions are made after the study. (1) The aforementioned key formula is general enough to cover other formulas derived by other researchers. (2) The key formula combined with Lambert*s assumption predicts the low-cycle fatigue damage and fatigue life very well. (3) A new derived formula can be used to predict the high-cycle fatigue damage and fatigue life. In the second part of the dissertation, Elber*s law is adopted for the cycle-by-cycle fatigue crack growth simulation. For each run of the simulation, various factors such as the applied load and the material constants are considered random factors. For each random factor, either a random variable or a random process is assumed, and its effect on the scatter of the crack growth curves is investigated. Experimental crack growth data of Type 4340 steel alloy are used for comparison. It is found that if one considers a certain material constant a random variable, the simulation result agrees rather well with the experimental result. It is also found that if one considers any one of the considered parameters as a random process, the scatter among different growth curves is smaller than the real experimental result. A random process with certain correlation length may be appropriate to account for the scatter of the real crack growth curves.
42
Chu, Jaffery, e 朱祐賢. "Research on the Bulking and Fatigue Properties of Rail". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/70540225068968846035.
Testo completoAbstract (sommario):
碩士國立中興大學
土木工程學系
90
ABSTRACT The south bound train of CHU KUANG NO.41 of Taiwan Railway Administration had a traffic accident at 10:17AM, 13 July, Friday, 2001.The cause of this accident is the main subject of this study. Two research methods were used in this paper: numerical analysis and experimentation. For numerical analysis, we will use structure analysis or theory reason to analyze the bulking load on 50kgN rail, and determine the lateral torsion and the temperature effects on the bulking load. For experimentation, we will study the effect of metal fatigue on material and structure properties. According to the research results, three million times fatigue vibration had no effect on the materials and the rail structure properties. The bulking load of 50kgN rail destroy mode was designed to support 35 tons. However, the axial load and temperature effects alone reached about 32.4 tons on that day. If the movement loads of the trains, including acceleration and deceleration, are added together, the total axial load might exceed 35 tons, which would cause bulking destruction. Additionally, Regulations of Taiwan Railway Administration stipulate that 400kg/m of lateral resistance on the ballast track is suitable, but it seems that the lateral resistance between slab track and ballast track is unsuitable. This paper will describe the suggestions for improvement.
43
Tseng, Hsiu-Fen, e 曾秀芬. "The Research of Operators’ Visual Fatigue in Lithographic Area". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/59443062902232521683.
Testo completoAbstract (sommario):
碩士中國文化大學
勞工研究所
90
Abstract Because the photolithographic processing in semiconductor has to be done under yellow light, it’s also called lithographic area （yellow light district）. Some papers show that operators of lithographic area generally have the problem in visual fatigue. There are many factors causing visual fatigue; related researches point out the main reason for operators’ visual fatigue may be the yellow light and microscopic process. Therefore, this research is focused on these two aspects. The results show that the subjective symptom of visual fatigue has higher incidence in yellow light than in the white light. As for other subjective symptoms, the “sore eyes” is the highest prevalence in yellow light and white light. The operators of yellow light have more statistically significance in「headaches」than those of white light. The subjective symptoms of visual strain have higher incidence in yellow light than in the white light. The near-point distance is significantly higher in yellow light than in the white light. It shows that the yellow light operators are apt to have the subjective symptom of visual fatigue problem. In the aspect of the subjective symptom of visual fatigue, prevalence after work is significantly higher in microscopic processing than non-microscopic processing one, as well in the degree of severity and incidence. As for other subjective symptoms, the “sore eyes” is the highest prevalence in microscopic processing and non-microscopic processing. The frequency of “hard—to—see-things” and “dizziness” lasting after work in the past week is more frequent in microscopic processing every day. The critical flicker fusion is significantly lower in microscopic processing operators than in non-microscopic processing ones. The near point distance is on increase in yellow light and white light, but microscopic processing operators significantly increase in the near-point distance. It shows that the microscope operators have visual fatigue problems. Above all, we can’t get the further inference whether the yellow light itself will cause visual fatigue due to the deficiency of the sample. However, we learn that the problem of the operators’ visual fatigue in the lithographic area may be related to microscopic processing as well. So, devoted to improving microscopic processing will be helpful for the operators to lower the occurrence of visual fatigue.
44
Adams, Denise Lauren. "Traditional Chinese medicine evidence and challenges in fatigue clinical research /". 2010. http://hdl.handle.net/10048/1140.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--University of Alberta, 2010.A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Department of Public Health Sciences. Title from pdf file main screen (viewed on April 28, 2010). Includes bibliographical references.
45
Adams, Denise. "Traditional Chinese medicine: evidence and challenges in fatigue clinical research". Phd thesis, 2010. http://hdl.handle.net/10048/1140.
Testo completoAbstract (sommario):
The increasing popularity of traditional Chinese medicine (TCM) therapies as health care options warrants thorough examination of the efficacy and safety evidence around these therapies. This thesis explores the intersection of TCM and fatigue using two rigorous methodologies: systematic reviews (SRs) and a randomized controlled clinical trial (RCT). In order to inform the development of an RCT of acupuncture for infectious mononucleosis (mono), a common condition with no known cure, characterized by profound fatigue, we examined the literature on TCM treatment of mono as well as another fatigue condition, idiopathic chronic fatigue (ICF). Additionally, we investigated the literature on the safety of pediatric acupuncture.
SRs of TCM efficacy in mono and ICF determined that although clinical trials exist, methodological flaws compromised their validity. In particular, studies published as RCTs were found to lack proper randomization. Inclusion of these studies in the SRs would have been inappropriate and demonstrates the importance of verifying RCT methods.
We also present the results of the first known SR of pediatric acupuncture safety. This review was comprehensive, including a large number of databases and publications in any language. Synthesis of the results from those studies that included a denominator produced mild adverse event estimates of 16.3/100 (95% CI 11.221.5) per patient, for RCTs, and 6.3/100 (95% CI 4.97.7) per patient, for cohort studies, with a combined estimate of 7.8/100 (95% CI 6.49.2) per patient.
We developed and conducted an RCT of acupuncture for mono, although limitations to recruitment resulted in the enrolment of only three participants. The primary result of the small sample size was to restrict the determination of treatment effect, however, successful implementation of other elements is informative to further research in this area. In addition, we determined the local 5-year Monospot positive incidence rate to be 1.11/1000 (95% CI 0.953.2) for all ages and 5.46/1000 (95% CI 0.8910.0) for the 15-25 year old group.
This dissertation examined the evidence around TCM and fatigue and provides recommendations that are aimed at increasing the value of research and the safety and efficacy of practice in this area.
46
WANG, EN-WEI, e 王恩偉. "Research of NiTi Wires Thermal Fatigue On Constant-Strain Test". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/k2g3vt.
Testo completoAbstract (sommario):
碩士國立高雄科技大學
模具工程系
107
Nitinol alloy consisting of equal amounts of Ni and Ti (49: 51 atom%) has a unique shape memory effect (SME), which has a great impact on the field of actuators. In this study, the thermal fatigue test of Nitinol wire was performed by constant-strain. The experiment was carried out with different wire diameters (0.100 mm, 0.127 mm, 0.150 mm) and two different austenite transformation temperatures (Af 70 °C and Af 80 °C). Nitinol wire, which is mounted on a fixed strain tester with fixed strain (1 ~ 5%) and set the current value (480 mA, 650 mA, 800 mA, 840 mA) for thermal fatigue test. The experimental results of Af 80°C wire with different fixed strain shows that wires on small fixed strain has longer fatigue life than bigger ones. On the other Af 70 °C wire shows different results. The strain value increases with its fatigue life rises from 10,000 times to 20,000 times. The main reason for the investigation is that Stress-Induced Martensitic by the R phase causes to provide the better strength and fatigue property for the wire, and the presence of the R phase also gives 0.150 (70) better functional fatigue stability, so that the thermal cycle shrinkage stress of the wire is much lower than others.
47
Lin, Yi-Chieh, e 林宜潔. "The Research of Graduate Students' Fatigue Assessment by Using Mobile Devices". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/9m5tv8.
Testo completoAbstract (sommario):
碩士國立雲林科技大學
工業工程與管理系
105
With the help of rapid technological development, various wearable devices and mobile applications have been developed subsequently. The main purpose of this research is to detect graduate students' fatigue by using mobile devices and applications. The physiological parameters which are measured by mobile devices and applications will be compared with the results of fatigue scale which is Checklist Individual Strength. The fatigue evaluation rules should be established and the quantitative fatigue level will be determined expectedly. This research proposed a fatigue detection system instead of fatigue scales. The mobile devises will be more widely used to monitor the human physiological changes. The medical cost can be reduced. The healthcare quality and personalized medicine can be more improved.
48
LEE, WEI CHIEH, e 李為杰. "Research on the Influence of Mobile Phone Screen on Visual Fatigue". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5qw9y5.
Testo completoAbstract (sommario):
碩士中華大學
工業管理學系
106
ABSTRACT Along with The change of the Times, the progress of science and technology, created the convenience of life, such as mobile phones, computers and other hard equipment, but as people rely on the convenience of these hard equipment, the use of time has become longer, but because of the use of time is too long, causing the human eye of sour, dizzy, vision loss, fatigue and other discomfort symptoms. Therefore, this study explores the effects of different brands of mobile phone screens on vision and visual fatigue, and mainly aims to explore the effects of high resolution and low pixel on the human eye and visual fatigue. Therefore, the effects of the different brands ' screen on the left eye, the right eye, the binocular vision and the visual fatigue were calculated with SAS and SPSS. The results showed that the visual acuity of the left eye was more serious than that of the mobile screen with high resolution. But in the right eye vision, the exact opposite. It is generally believed that high resolution has a positive effect on users, which is different from the conclusion of this study. The reason, according to the past scholars in the study, the impact of the two eye vision for the high and low resolution of the reasons, because the screen picture of the sense of three-dimensional feeling will be different people's left and right eye spacing difference, the dominant hand is different, resulting in the impact on the left eye vision. In the visual fatigue analysis, the higher the resolution of the mobile phone screen than the lower resolution of the mobile phone screen, resulting in more severe eye fatigue. In other words, the higher the resolution, the greater the sense of visual fatigue that accelerates the eye's fatigue. It is generally considered that the resolution is high, the screen quality is relatively high, in the user's job, the need to spend time and energy on the relative to the small, feel less fatigue. But the high resolution screen, visual performance alone and will be able to reduce the user's eye damage, for the eye fatigue due to high resolution, screen more stereo and shock, so that the eye visual fatigue is more serious. Conversely, the screen with low resolution, the eye needs to spend more energy and time to search, view and work, therefore, resulting in poor visual performance, but for the eye fatigue degree is better. It is hoped that by the conclusion of this study, the follow-up operators and consumers in the development, manufacture and purchase of reference. Keywords: Mobile phone screen, single factor variance, single factor common variable, visual fatigue
49
Frazer, Melanie. "A cognitive behavioural treatment programme for chronic fatigue syndrome sufferers". Thesis, 2012. http://hdl.handle.net/10210/7142.
Testo completoAbstract (sommario):
D.Litt. et Phil.The goal of this study was to determine the impact of cognitive behavioural therapy on people who meet the international diagnostic criteria for CFS, by specifically looking at symptoms and health behaviour. Whereas CFS was originally only studied from a medical perspective, recent years have seen an increased interest from psychologists. Initially the debate centered around whether CFS was a medical or psychiatric illness, but with the development of health psychology as a recognised field of its own, the focus shifted to the investigation of how medical and psychological factors work together to create the symptomatology of CFS. The approach adopted by the research team was that CFS was a biopsychosocial illness and that biological factors such as genetic predisposition, psychological factors such as cognitions and emotions and social factors such as the pressures of families and society work together to establish the health of a person. The study thus set out to gather information regarding all of these aspects in order to add to the current body of knowledge. As previous research efforts had been critisised regarding the validity of the diagnosis of the CFS patients included in their samples, an important challenge that was faced by the researcher was to establish that all the research group participants did meet with the diagnostic criteria. It also had to be ensured that their symptoms could not be accounted for by any other medical illness that was listed as an exclusion criteria for CFS. In order to achieve this patients who had not already had the necessary medical tests done, were requested to do so. The therapeutic intervention was based on cognitive behavioural principles which had been proven to be effective in the treatment of other illnesses that had a biological as well as psychological , aspect to it, for example anxiety, fibromyalgia and chronic pain. The aspects that were addressed had been found by previous researchers to be of great importance in a therapeutic intervention for CFS. These aspects included illness beliefs, information regarding CFS, locus of control and coping mechanisms, avoidance, activity levels, negative and dysfunctional thoughts, social support, lifestyle changes, stress management, sleep, exercise and personality factors. The specific techniques that were included in the intervention were self monitoring, monitoring and modifying of dysfunctional thoughts, goal setting, relaxation and systematic desensitisation. The research group consisted of 37 patients who met the internationally accepted diagnostic criteria for CFS. The control group was a contrast group of comparable size, which included only people who were free from psychological disorders and medical illnesses. The research group participated in a cognitive behavioural intervention, which was designed around the needs of each individual. They therapy was conducted at a community clinic at Rand Afrikaans University between February 1995 and October 1995. Pretests were completed upon commencement of the therapy and the posttests upon termination of the therapy. The control group completed their pre- and posttests at the average interval of the research group pre- and posttests. In order to make a multi-dimensional assessment of the impact of the cognitive behavioural intervention on CFS, various instruments were ulitised. The first instrument was a biographical questionnaire, which recorded the name, sex, age, income group, highest formal qualification, type of work, etcetera. The second questionnaire was an adapted version of the Support and Service Utilisation Schedule, which was employed to control for the other medical and therapeutic interventions that patients participated in, for example the medication taken, alternative medical practitioners visited and sources of support. The participants were asked to maintain their use of these services that they had been using for a long period and to not embark on any new therapies and treatments while they were partaking in the cognitive behavioural intervention.
50
Tang, Yushun, e 湯禹舜. "Research of Accommodative Microfluctuations Caused by Visual Fatigue Based on 3D Display Platforms". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/e494ax.
Testo completoAbstract (sommario):
碩士國立交通大學
電控工程研究所
101
The appearance of different colors and images causes different levels of visual fatigue in the human eye. Research uses the spectral power of high frequency component of accommodative microfluctuations as a major objective indicator for analyzing the effects of visual fatigue through color formation methods, 3D display technologies, light sources and individual differences. A questionnaire is used as a subjective indicator. Color formation methods involved in the research are time sharing and spatial formation method, and the 3D display technologies use shutter and polarized glasses; Light sources are light emitting diode (LED) backlights and mixed LED and laser diode (LD) lights. So far the color break-up from time sharing method has been known to make human eyes tire easily. This research used devices such as: a shutter 3D LCD TV, a polarized 3D LCD TV and a laser projector. Firstly, the subjects’ color discrimination was examined by the hue test, and then, at another time, by viewing 3D and 2D videos at the same visual range to stimulate the eyes. Before and after the experiment the subjects’ accommodative microfluctuations were measured by the auto refract-keratometer, and then a questionnaire was filled in. Finally the analysis of variance (ANOVA) and a t-test were used for analysis. Conclusions are: (1) 3D videos afflict greater visual fatigue than 2D videos (p<0.001). (2) The shutter glasses afflict more visual fatigue than the polarized glasses (p=0.012). (3) Time sharing method afflicts greater visual fatigue more than spatial formation method (p=0.008). (4) There is no difference between the LED backlight and mixed LED and LD lights (p=0.162). (5) In general, people with normal color discrimination have more visual fatigue than those with the good (p<0.001), but the visual discomfort are the same on LCD TVs and polarized system. (6) The HFC can evaluate the physiological stress or strain by overexerting the visual system, which then leads to visual fatigue. Rudimentary relationships have been found between different colors and images appearances and visual fatigue. However, more detailed research is required using different parameters, and visual fatigue could be monitored with the development of an advanced real-time sensor.