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Dissertations / Theses on the topic 'Diagnostic reliability'
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Lachner, Gabriele, Hans-Ulrich Wittchen, Axel Perkonigg, Alexandra Holly, Peter Schuster, Ursula Wunderlich, Dilek Türk, Ela Garczynski, and Hildegard Pfister. "Structure, Content and Reliability of the Munich-Composite International Diagnostic Interview (M-CIDI) Substance Use Sections." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99961.
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After reviewing currently available diagnostic assessment instruments for substance use disorders this paper describes the format and structure of the Munich-Composite International Diagnostic Interview (M-CIDI) substance disorder section. In addition, the test-retest reliability of diagnoses and criteria for nicotine, alcohol, illegal and prescription drugs, is reported. Findings obtained in community sample of adolescents and young adults indicate that the substance section is acceptable for almost all types of respondents, efficient in terms of time and ease of administration as well as reliable in terms of consistency of findings over time. The test-retest reliability over a period of an average of 1 month, as examined by two independent interviewers indicates good-to-excellent kappa values for all substance disorders assessed, with significant kappa values ranging between 0.55 for drug abuse and 0.83 for alcohol abuse. There was also fairly consistently high agreement for the assessment of single DSM-IV diagnostic criteria for abuse and dependence as well as the M-CIDI quantity-frequency and time-related questions. To conclude, although – unlike previous studies – this study was conducted in a community sample and not in patients and used considerably longer time intervals of more than a month between investigations, our M-CIDI reliability findings are at least as high as those from previous studies.
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Reller, Susan R. "Reliability diagnostic strategies for series systems under imperfect testing." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45926.
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An expected cost model was developed for failure detection in series systems under imperfect testing. Type I and type II error probabilities are included and single-pass sample paths are required. The model accounts for the expected costs of testing components, false positive termination, and no-defect-found outcomes.
Based on the model, a heuristic was developed to construct the cost minimizing testing sequence. The heuristic algorithm utilizes elementary arithmetic computations and has been successfully applied to a variety of problems. Furthermore, the algorithm appears to be globally convergent. Choice of a starting solution affects the rate of convergence, and guidelines for selecting the starting solution were discussed. Implementation of the heuristic was illustrated by numerical example.Master of Science
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Srinivasan, Soorya. "Reliability and Accuracy of Assessing TAD - Tooth Root Contact using CBCT." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1553782462280014.
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Chandroth, Gopinath Odayammadath. "Diagnostic classifier ensembles : enforcing diversity for reliability in the combination." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322873.
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Roy, Abhijit Sinha. "Diagnostic Reliability of Guidewire in Evaluation of Coronary Artery Stenoses." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1100280001.
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Lachner, Gabriele, Hans-Ulrich Wittchen, Axel Perkonigg, Alexandra Holly, Peter Schuster, Ursula Wunderlich, Dilek Türk, Ela Garczynski, and Hildegard Pfister. "Structure, Content and Reliability of the Munich-Composite International Diagnostic Interview (M-CIDI) Substance Use Sections." Karger, 1998. https://tud.qucosa.de/id/qucosa%3A26272.
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After reviewing currently available diagnostic assessment instruments for substance use disorders this paper describes the format and structure of the Munich-Composite International Diagnostic Interview (M-CIDI) substance disorder section. In addition, the test-retest reliability of diagnoses and criteria for nicotine, alcohol, illegal and prescription drugs, is reported. Findings obtained in community sample of adolescents and young adults indicate that the substance section is acceptable for almost all types of respondents, efficient in terms of time and ease of administration as well as reliable in terms of consistency of findings over time. The test-retest reliability over a period of an average of 1 month, as examined by two independent interviewers indicates good-to-excellent kappa values for all substance disorders assessed, with significant kappa values ranging between 0.55 for drug abuse and 0.83 for alcohol abuse. There was also fairly consistently high agreement for the assessment of single DSM-IV diagnostic criteria for abuse and dependence as well as the M-CIDI quantity-frequency and time-related questions. To conclude, although – unlike previous studies – this study was conducted in a community sample and not in patients and used considerably longer time intervals of more than a month between investigations, our M-CIDI reliability findings are at least as high as those from previous studies.
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Bergeron, Sophie 1968. "A biopsychosocial approach to vulvar vestibulitis syndrome : diagnostic reliability and treatment outcome." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35855.
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Vulvar vestibulitis is a highly prevalent and underinvestigated pain syndrome that is considered the most common subtype of dyspareunia, or painful intercourse, in pre-menopausal women. The first chapter of this thesis consists of a critical review of the vulvar vestibulitis literature, covering descriptive, diagnostic, etiologic, and treatment aspects. This is followed by a retrospective study of 38 women, investigating the success of vestibulectomy, a frequently recommended medical treatment for vulvar vestibulitis. Results from structured telephone interviews pertaining to dyspareunia and sexual function show that 63.2% of participants experienced a significant improvement or a complete cure while 36.8% reported moderate to no improvement. The third and fourth chapters are based on a randomized treatment outcome study of women with vulvar vestibulitis. Data from 146 participants taking part in the recruitment phase of the treatment outcome study were used to investigate the reliability of the vulvar vestibulitis diagnosis. Findings demonstrate moderate to substantial inter-rater agreement and test-retest reliability. The fourth paper reports results from the randomized comparison of 78 women meeting study selection criteria and assigned either to group cognitive-behavioral therapy, surface electromyographic biofeedback, or vestibulectomy. They were assessed at pretreatment, posttreatment and 6-month follow-up via gynecological examinations, a structured interview and standard questionnaires pertaining to dyspareunia, sexual function, and psychosocial adjustment. Results from the treatment outcome study demonstrate that (1) participants from the three treatment conditions significantly improve from pretreatment to 6-month follow-up on all pain measures, and (2) vestibulectomy is significantly more successful than biofeedback and group cognitive-behavioral therapy in relieving vulvar vestibulitis. Findings from this set of studies suggest that vulvar vestibuliti
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Bergeron, Sophie. "A biopsychosocial approach to vulvar vestibulitis syndrome, diagnostic reliability and treatment outcome." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0022/NQ50111.pdf.
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Pereira, Raul Alexandre Marques. ""Reliability of diagnostic procedures in medical imaging: Narrow Band Imaging Endoscopy in gastric disease"." Dissertação, Faculdade de Medicina da Universidade do Porto, 2009. http://hdl.handle.net/10216/55712.
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Atamer, Allen 1976. "Reliability evaluation of an expert system diagnostic aid for a sleep and respiration experiment." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/81556.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2001.Pages 127-130 blank.
Includes bibliographical references (p. 95-96).
by Allen Atamer.
S.M.
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Pereira, Raul Alexandre Marques. ""Reliability of diagnostic procedures in medical imaging: Narrow Band Imaging Endoscopy in gastric disease"." Master's thesis, Faculdade de Medicina da Universidade do Porto, 2009. http://hdl.handle.net/10216/55712.
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Knappe, Susanne, Jens Klotsche, Franziska Heyde, Sarah Hiob, Jens Siegert, Jürgen Hoyer, Anja Strobel, et al. "Test–retest reliability and sensitivity to change of the dimensional anxiety scales for DSM-5." Cambride University Press, 2014. https://tud.qucosa.de/id/qucosa%3A39010.
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Objective. This article reports on the test–retest reliability and sensitivity to change of a set of brief dimensional self-rating questionnaires for social anxiety disorder (SAD-D), specific phobia (SP-D), agoraphobia (AG-D), panic disorder (PD-D), and generalized anxiety disorder (GAD-D), as well as a general cross-cutting anxiety scale (Cross-D), which were developed to supplement categorical diagnoses in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Methods. The German versions of the dimensional anxiety scales were administered to 218 students followed up approximately 2 weeks later (Study 1) and 55 outpatients (23 with anxiety diagnoses) followed-up 1 year later (Study 2). Probable diagnostic status in students was determined by the DIA-X/M-CIDI stem screening-questionnaire (SSQ). In the clinical sample, Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnoses were assessed at Time 1 using the DIA-X/M-CIDI. At Time 2, the patient-version of the Clinical Global Impression— Improvement scale (CGI-I) was applied to assess change. Results: Good psychometric properties, including high test–retest reliability, were found for the dimensional scales except for SP-D. In outpatients, improvement at Time 2 was associated with significant decrease in PD-D, GAD-D, and Cross-D scores. Discussion. Major advantages of the scales include that they are brief, concise, and based on a consistent template to measure the cognitive, physiological, and ehavioral symptoms of fear and anxiety. Further replication in larger samples is needed. Given its modest psychometric properties, SP-D needs refinement. Conclusion. Increasing evidence from diverse samples suggests clinical utility of the dimensional anxiety scales.
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Stephenson, Heather Lynn. "Screening and Diagnostic Validity of Affinity 2.5." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4232.
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Affinity 2.5 is a computer-based instrument designed to assess sexual interest using viewing-time measures. Viewing-time measures of sexual interest have been developed to identify individuals with deviant sexual interest. The purpose of this study is to examine the validity of Affinity 2.5 in screening and diagnosing individuals with sexually deviant interests. This study used viewing time profiles of known sexual offenders compared to norm-referenced profiles of an exclusively heterosexual, non-pedophilic college population. Participants were 155 males and 3 females who had sexually offended against children and 63 male and 84 female non-offender college students. Results show that 43.7% of offenders were correctly identified as having significantly deviant sexual interest, compared to the reference group. Further 12.0% of offenders showed statistical significant interest in at least one category of individuals from a protected population and offended against that same category. The results of this study do not provide support for the utility of the Affinity 2.5 as a screening or diagnostic tool.
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Patel, Chandni. "Reliability Generalization of the Alcohol Use Disorders Identification Test." Digital Commons @ East Tennessee State University, 2008. https://dc.etsu.edu/etd/1973.
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The Alcohol Use Disorder Identification Test (AUDIT) is a brief screening instrument for assessing alcohol use problems among adults. This instrument is widely used and continued evaluation of its psychometric performance is needed. Reliability and validity are the primary psychometric characteristics of interest when evaluating psychological instruments. The focus of the present study is on reliability, which reflects the consistency or repeatability of the scores produced by a given instrument. Using meta-analytic methods, results showed that approximately 65% of previously published studies using the AUDIT did not appropriately report reliability estimates. Among the remaining studies, weighted reliability estimate centered on .81 (SD = .07) suggesting that the AUDIT generally produces scores of adequate reliability for most research purposes. Multiple regression equations showed that, among a variety of sample and methodological characteristics, the standard deviation of scores was the only statistically significant predictor of the variability in AUDIT score reliability estimates.
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Wittchen, Hans-Ulrich, Lee N. Robins, Linda B. Cottler, Norman Sartorius, J. D. Burke, and Darrel A. Regier. "Cross-cultural Feasibility, Reliability and Sources of Variance of the Composite International Diagnostic Interview (CIDI)." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-108560.
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The CIDI is a fully standardised diagnostic interview designed for assessing mental disorders based on the definitions and criteria of ICD-1Oand DSM-IlI-R. Field trials with the CIDI have been conducted in 18 centres around the world, to test the feasibility and reliability of the CIDI in different cultures and settings, as well as to test the inter-rater agreement for the different types of questions used. Of 590 subjects interviewed across all sites and rated by an interviewer and observer, 575 were eligible for analysis. The CIDI was judged to be acceptable for most subjects and was appropriate for use in different kinds of settings. Many subjects fulfilled criteria for more than one diagnosis (lifetime and six-month). The most frequent lifetime disorders were generalised anxiety, major depression, tobacco use disorders, and agoraphobia. Percentage agreements for all diagnoses were above 90% and the kappa values were all highly significant. No significant numbers of diagnostic disconcordances were found with lifetime, six-month, and four-week time frames.
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Steiner, Markus F. C. "Workplace health surveillance for occupational skin diseases : diagnostic accuracy and reliability of a teledermatology tool." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=186732.
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Occupational skin diseases is one of the most commonest occupational disease groups accounting for about a fifth of all occupational diseases in the UK. Current guidance from the HSE for skin health surveillance is the skin inspection by a responsible person in the workplace. The use of teledermatology can be attractive to reliably conduct skin surveillance in the workplace, and a tool box to take reproducible standardised photographs from the hands of workers in the workplace was developed. Aim of this thesis was to assess diagnostic accuracy and validity of this toolkit with visual inspection as criterion standard for the presence of minor or major hand dermatitis and by scoring the hands and photographs with the validated Hand Eczema Severity Index. Workers from four different occupations were recruited over a 7 month period and 332 workers were assessed on a repeatedly basis producing 1212 assessments. Skin hydration and transepidermal water loss was measured and a symptoms questionnaire was completed by every participant. A high prevalence of skin problems was found in our study: 70% of the participants presented at least once over the study period with minor or major skin symptoms. A high intrarater reliability compared to the visual assessment was shown for the teledermatologic assessment with an agreement of 88%, kappa of 0.79, and a positive likelihood ratio of 7.4 and negative likelihood ratio of 0.07; about 5% of participants with normal skin were over-diagnosed compared to the visual inspection. The interrater reliability was low. The biophysical parameter did not distinguish between normal and affected skin. The tool kit has shown to produce reliable and standardised high quality photographs, the assessment of the photographs showed a very good intrarater agreement to the criterion standard. The toolkit would allow regular skin surveillance with minimal interruption in the workplace and with reliable results from the assessment.
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Wittchen, Hans-Ulrich, Lee N. Robins, Linda B. Cottler, Norman Sartorius, J. D. Burke, and Darrel A. Regier. "Cross-cultural Feasibility, Reliability and Sources of Variance of the Composite International Diagnostic Interview (CIDI)." Technische Universität Dresden, 1991. https://tud.qucosa.de/id/qucosa%3A26759.
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The CIDI is a fully standardised diagnostic interview designed for assessing mental disorders based on the definitions and criteria of ICD-1Oand DSM-IlI-R. Field trials with the CIDI have been conducted in 18 centres around the world, to test the feasibility and reliability of the CIDI in different cultures and settings, as well as to test the inter-rater agreement for the different types of questions used. Of 590 subjects interviewed across all sites and rated by an interviewer and observer, 575 were eligible for analysis. The CIDI was judged to be acceptable for most subjects and was appropriate for use in different kinds of settings. Many subjects fulfilled criteria for more than one diagnosis (lifetime and six-month). The most frequent lifetime disorders were generalised anxiety, major depression, tobacco use disorders, and agoraphobia. Percentage agreements for all diagnoses were above 90% and the kappa values were all highly significant. No significant numbers of diagnostic disconcordances were found with lifetime, six-month, and four-week time frames.
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Reissing, Elke D. "Re-evaluating vaginismus : an empirical investigation of diagnostic reliability, vaginal spasm, pain, and associated etiological correlates." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38514.
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Vaginismus is a sexual dysfunction that has received insufficient empirical attention. The first chapter of this thesis consists of a critical review of the literature and demonstrates the overall paucity of research studies and their poor methodological quality. The second and third chapter are based on the results of an experimental study comparing 87 women, matched on age, relationship status, and parity and assigned to 3 groups, vaginismus, dyspareunia/vulvar vestibulitis syndrome (VVS), and no pain. A structured interview evaluating pain with intercourse and history of gynecological problems as well as psychometric measures; evaluating sexual and physical abuse, sexual knowledge and schema, sexual functioning, relationship adjustment and psychological distress were administered. The reliability of vaginal muscle spasm as the main diagnostic criterion, differential diagnosis, and the role of pain were assessed via by 2 separate gynecological and, 2 separate physical therapist examination, 2 EMG evaluations, and a review of the interview data by 2 separate psychologists. Findings suggest that the spasm-based definition and resulting diagnostic reliability of vaginismus are not adequate. Both, women in the vaginismus and VVS groups exhibited higher levels of pelvic floor hypertonicity compared to women with no pain; however, women in the vaginismus group demonstrated the highest levels. Measures of pain did not distinguish between women with vaginismus and VVS. The only dependent measure clearly differentiating women with vaginismus was defensive and avoidant reactions during the physical exams. A re-conceptualization based on a multidimensional diagnostic framework including pelvic floor hypertonicity, avoidance and defensive reactions to vaginal penetration, and genital pain was suggested. The third paper was based on the results of questionnaires investigating etiological correlates of vaginismus, sexual and physical abuse, sexual self-schema, sexual knowled
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Ahmadi, Shamila. "The validity and reliability of the abbreviated version of the diagnostic interview for borderlines (DIB-Ab) /." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32745.
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Objective. The diagnostic interview for borderline personality disorder (DIB) requires a long duration of administration (45 minutes). This led to the development of a briefer (10 minutes), and therefore more feasible, version of the DIB named the DIB-Ab. It is the aim of this study to test the validity and reliability of the DIB-Ab. Method. Forty-seven previously suicidal adolescents, aged 14--21 years, participated in this study. The DIB-Ab and DIB-R were administered during a battery of tests separated by 130 minutes of unrelated measures. Results. The Pearson correlation coefficient of the DIB-Ab with respect to the DIB-R ranged from .52--.80 with respect to the total scores on three sections (i.e. affect, cognition, and impulse/action). The correlation coefficient of the DIB-Ab ranged from .43--.91 for the total section scores and the same section scores. The standardized alpha for internal consistency of the DIB-Ab ranged from .54--.83 for the total scores and for cognition and impulse/action section scores. Conclusion. The preliminary data analysis revealed that the DIB-Ab is a valid and reliable instrument, and it could replace the parent version in certain research and clinical paradigms.
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Cantin, Peter. "Quality assurance procedures in non-obstetric diagnostic ultrasound : a study of the reliability of current methods." Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/29694.
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Introduction: This study aimed to address some of the issues and inconsistencies around clinical quality assurance mechanisms in (non-obstetric) diagnostic medical ultrasound. Quality assurance and resultant quality improvement in this field is sporadic with a plethora of different methodologies, techniques and quality assurance measurements tools. The evidence-base upon which programs are designed is weak with little high quality primary research in this subject area. This study aimed to clarify some of the uncertainties around clinical quality assurance mechanisms in this field of medical imaging. Methodology: A website was created which allowed the retrospective review of ultrasound imaging and clinical reports to be undertaken on-line. Clinical ultrasound cases were selected which covered a wide spectrum of clinical quality and these cases were uploaded onto this site. Study participants were ultrasound practitioners invited from several professional backgrounds and levels of clinical experience who reviewed this imaging and scored the ultrasound examinations using several different quality assessment tools. The on-line method of image dissemination facilitated a geographically diverse group of ultrasound practitioners to evaluate the same imaging and clinical reports using the quality assurance measurement tools provided. Outcome measurements included degree of inter-rater agreement between participants for each quality assessment tool. Systematic differences between different reviewers were also assessed. Participants were given the opportunity to leave comments regarding the imaging that they had reviewed on the website if they wished. The content and tone of these comments was also analysed. Results: The inter-rater agreement was classed as ‘fair’ for all the quality assurance tools under investigation. There was no significant difference between any of the quality measurement tools in terms of inter-rater agreement. Correlation between tools was good. There were weak systematic differences found between reviewers. Practitioners of more clinical experience rated image quality more highly than those of lesser clinical experience. Practitioners of lower clinical grade tended to rate the quality of clinical report more highly than those of a higher clinical grade. Participant comments were evenly divided between comments on clinical technique and comments on the quality of the written report. An ultrasound specialist judged that ‘expert-group’ participants were more likely to give constructive comments than a ‘peer-group’ of reviewers, but this finding was not confirmed when the comments were analysed by a non-specialist in clinical ultrasound. Overall, there were slightly more constructive comments than non-constructive, but a large proportion of the comments were judged to be non-constructive in nature. Conclusions: The study demonstrated significant inter-rater variation in quality assessment of diagnostic ultrasound which is probably inherent within the imaging modality itself. Efforts should be directed to managing this variation rather than attempting to eradicate it. There are some systematic differences between study participants but there was insufficient data to accurately model the precise systematic effects of different participant characteristics and this requires further research with a larger cohort of study participants. There is scope to improve the quality of feedback to ultrasound practitioners, particularly when this is subjective in nature to maximise the probability of this resulting in positive subsequent change. Formal tuition in the theory and practice of giving feedback should be available to all staff undertaking quality assurance work, irrespective of their degree of expertise, clinical grade or clinical experience. Recommendations for Clinical Practice. The following clinical recommendations have been made, based on the evidence gained from this study; • Quality assurance of non-obstetric ultrasound examinations should ideally be undertaken by those of a higher clinical grade than those undertaking the work being appraised. Peer audit may be acceptable providing there is effective oversight by a senior clinical practitioner. • The use of a single, expert reviewer in diagnostic ultrasound does not provide adequate assurance in terms of inter-rater reliability and therefore should not be used. A quality assurance program based on retrospective assessment of ultrasound imaging and clinical reporting should be undertaken by several reviewers to buffer against the effects of inter-reviewer variation. • Use of the internet provides great advantages in terms of overcoming logistical difficulties in undertaking quality assurance in ultrasound, particularly when undertaken by an external reviewer. However, individual feedback should be given to ultrasound practitioners face-to-face by the senior practitioner responsible for the quality assurance program. • Those undertaking quality assurance work, regardless of clinical grade and expertise should receive formal training in giving feedback in a constructive fashion. The purpose is to maximise the potential for this feedback to lead to improved clinical standards and outcomes for patients. • There is currently no primary research evidence to favour one quality assurance tool over another. Quality assurance tool selection may therefore be done at an individual ultrasound unit level. In selection of a quality assurance tool, ultrasound units should consider which tool best reflects the individual requirements and workload of that unit.
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Hübková, Ivana. "Uplatnění diagnostických metod na zařízeních paroplynového bloku." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219905.
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This master´s thesis deals with problem of reliability of technical device in general a so there is explained bathtub curve, defects and malfunctions of devices and then there is a brief outline of reliability system. This thesis further briefly describes technical diagnostic and then there is performed the vibrodiagnostic measurements of selected pumps and ventilators in in heating plant Červený mlýn in Brno. Evaluation of their condition is done according to relevant standards. Further there was done a diagnostic of the steam traps through the ultrasound diagnostic. The last part of my thesis deals with the reliability of selected specific pumps in foregoing rating plant. There are showed reliability curves of selected pumps and elaboration of data from their long-term vibrations measurement.
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AlKanhal, AbdulAziz A. "Novel cutaneous abscess model : model development and exploration of reliability and validity of detecting key diagnostic features." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54700.
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Introduction: The difficulty of differential diagnoses between cellulitis and occult cutaneous abscess remains the main issue in clinical practice. Educational efforts, however, have been invested into building simulation models directed toward the treatment of cutaneous abscesses. The discrepancy between the problem in clinical practice and educational efforts in this area requires simulation models that can provide an opportunity for trainees to practice their diagnostic skills.
Aims: The study focuses on creating a cutaneous abscess model that is detectable by ultrasound and evaluating the reliability and validity of detecting clinical and sonographic features of cutaneous abscess disease on the basis of the model.
Materials and methods: Six identical models were made, each consisting of a water balloon filled with mock abscess and two glue threads inside a pork belly, and radiologist standardized ultrasound images of the model. Reliability and validity of detecting key diagnostic features on the basis of the model by 24 judges were explored.
Results: Cronbach’s alpha across all models were 0.89 and 0.87 for clinical and sonographic features, respectively. The intraclass correlation coefficient was 0.71 for both clinical and sonographic features. The correlation between all clinical and sonographic features and corresponding construct were statistically significant (p < 0.01). Content validity indices were 0.90 for clinical features construct and 0.85 for the sonographic features construct.
Discussion: The model was constructed from simple, widely available and easy to assemble materials. It is a high fidelity, cost-effective model and can be used as a simulator for diagnosis of cutaneous abscess in medical education. Study data expressed excellent internal consistency and high agreement among judges. The clinical and sonographic features were significantly correlating to the overall corresponding construct. It also reveals strong content validity. The constructed cutaneous abscess model has reliable and valid ability in demonstrating both clinical and sonographic features. Further studies are needed to examine the efficacy of the model for training and correlations with the clinical outcomes in real practice.
Conclusion: The novel high fidelity cost-effective cutaneous abscess model allows for reliable and valid detection of the clinical and sonographic diagnostic features of the cutaneous abscess disease.Surgery, Department of
Medicine, Faculty of
Graduate
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Mynář, Josef. "Vliv frekvenčního měniče na životnost ložisek a jejich poškození." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378018.
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The diploma thesis deals with the technical diagnostics of machines with a closer focus on vibrational diagnostics. In the thesis is elaborated a design of a diagnostic system with measurement methodology, measurement procedure and evaluation of measured data on the machine produced by Siemens.
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Giovanetti, Gabriele. "Assessment of partial discharge activity and conductivity in IGBT modules as a reliability index." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amslaurea.unibo.it/25730/.
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Al giorno d’oggi l’elettronica di potenza deve essere in grado di operare in ambienti ostili e in condizioni di lavoro difficili. Il tema dell’affidabilità è diventato fondamentale quanto quello dell’efficienza. Questa tesi si focalizza sull’IGBT, in particolare sul suo sistema d’isolamento. Il primo passo è stato studiare in dettaglio i meccanismi di guasto possibili e più frequenti. Dal momento che le scariche parziali risultano essere un problema per l’affidabilità dei dielettrici solidi, in questo studio si esamina l’attività di PD su moduli IGBT nuovi ed invecchiati, in diverse configurazioni, con forme d’onda di tensione e temperature differenti. Si sono effettuate anche misure di corrente di dispersione su moduli nuovi ed invecchiati alla temperatura di lavoro. I risultati sono stati post-processati statisticamente tentando di ottenere indici di affidabilità per quei moduli. Quasi tutti i moduli invecchiati sono interessati da PD e i risultati mostrano che il PDIV, assieme ad altri fattori, è sicuramente influenzato dall’ageing. I risultati del monitoraggio della corrente di dispersione mostrano una tendenza all'aumento con l'invecchiamento. Si sono svolte anche simulazioni con software agli elementi finiti e rilevazioni ottiche di PD ed entrambe supportano i risultati ottenuti. È necessario effettuare ulteriori indagini su un data set più ampio al fine di migliorare un algoritmo di diagnostica predittiva basato sui valori di PDIV e conducibilità.
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Nguyen, Vu Quoc Huy. "Identification of progressive cervical squamous intraepithelial lesions using DNA image cytometry a study on diagnostic validity and reliability /." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968526322.
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Ben, Hassen Wafa. "Étude de stratégies de diagnostic embarqué des réseaux filaires complexes." Thesis, Toulouse, INPT, 2014. http://www.theses.fr/2014INPT0084/document.
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Cette étude s’inscrit dans le cadre du diagnostic embarqué des réseaux filaires complexes. Elle vise à détecter et localiser les défauts électriques avec précision. En effet, l’intégration du diagnostic par réflectométrie dans un système embarqué fait apparaître des problèmes d’interférence qui s’aggravent dans le cas d’un réseau complexe où plusieurs réflectomètres sont placés en différents points du réseau. L’objectif est de développer de nouvelles stratégies de diagnostic embarqué des réseaux filaires complexes pour résoudre les problèmes d’interférence d’une part et l’ambiguïté de localisation du défaut d’autre part. La première contribution concerne le développement d’une nouvelle méthode de réflectométrie baptisée OMTDR (Orthogonal Multi-tone Time Domain Reflectometry). Elle utilise des signaux numériques modulés et orthogonaux pour éliminer les interférences. Pour davantage de couverture, la deuxième contribution propose d’intégrer la communication entre les réflectomètres. Elle vise à fusionner les données afin de faciliter la prise de décision. La troisième contribution adresse la problématique de la stratégie de diagnostic, c’est-à-dire, de l’optimisation des performances du diagnostic d’un réseau complexe sous contraintes opérationnelles d’utilisation. L’utilisation des Réseaux Bayésiens permet d’étudier l’impact des différents facteurs et d’obtenir une estimation de la confiance et donc, de la fiabilité du résultat du diagnosticThis study addresses embedded diagnosis of complex wired networks. Based on the reflectometry method, it aims at detecting and locating accurately electrical faults. Increasing demand for on-line diagnosis has imposed serious challenges on interference mitigation. It aims at making diagnosis while the target system is running. The interference becomes more critical in the case of complex networks where several reflectometers are injecting their test signals simultaneously. The objective is to develop new embedded diagnosis strategies in complex wired networks that would resolve interference problems and eliminate ambiguity related to the fault location. The first contribution is the development of a new method called OMTDR (Orthogonal Multi-tone Time Domain Reflectometry). It uses orthogonal modulated digital signals for interference mitigation and thereby on-line diagnosis. For better coverage of the network, the second contribution proposes to integrate communication between reflectometers. It uses sensors data fusion to facilitate decision making. The third contribution addresses the problem of the diagnosis strategy, i.e. the optimization of diagnosis performance of a complex network under operational constraints. The use of Bayesian Networks allows us to study the impact of different factors and estimate the confidence level and thereby the reliability of the diagnosis results
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Perkel, Joshua. "The influence of critical asset management facets on improving reliability in power systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/31690.
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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Begovic, Miroslav; Committee Member: Hampton, Nigel; Committee Member: Harley, Ronald; Committee Member: Michaels, Thomas; Committee Member: Vidakovic, Brani. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Raikes, Adam. "The Reliability and Diagnostic Accuracy of the Yes/No Scapular Dyskinesis Test When Used By Graduate Assistant Athletic Trainers." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1203.
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Context: Scapular motion evaluation is a necessary component of the upper extremity exam. Several methods exist, but most lack good reliability or diagnostic accuracy. The yes/no scapular dyskinesis test has the best of both measures but is untested on inexperienced clinicians. Objective: The purpose of this study was to evaluate the reliability and diagnostic accuracy of the yes/no scapular dyskinesis test when used by graduate assistant athletic trainers. Participants: The participants were college-aged students with no prior history of upper extremity fracture or nerve injury. Data Collection and Results: Participants were evaluated for scapular dyskinesis by a physician and 10 graduate assistant athletic trainers. Ratings were for normal or dyskinetic and then determination of side. Reliability was calculated using Gwet’s AC1 statistic and diagnostic accuracy from standard 2x2 contingency tables. Results: Reliability was moderate (AC1 = 0.48, p < 0.0025, 95% CI [0.147, 0.812]) when side was not accounted for and moderate (AC1 = 0.43, p < 0.0001, 95% CI [0.242, 0.632]) when side-per-side decisions were made. Sensitivity and negative predictive values were low to moderate (34.4%-66.2%, 8.9%-74.1% ). Specificity and positive predictive values were moderate to high (50%-85.2%, 51.5%-95.2%). Accuracy was moderate (65.2%-69.4%) and positive and negative likelihood ratios were low (1.325-2.333, 0.675-0.769). Conclusions: The reliability in this study was on par with previously published studies. Measures of diagnostic accuracy met or exceeded previous results. Clinically, to avoid false negative results and enhance the use of positive results, it appears necessary to combine methods and begin the evaluation with a gross assessment of whether or not dyskinesis is present and if it is to then evaluate which side is dyskinetic.
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Adcock, Jane Elizabeth St Vincent's Clinical School UNSW. "The reliability and clinical validity of functional magnetic resonance imaging in the assessment of language in pre-surgical patients with temporal lobe epilepsy." Awarded by:University of New South Wales. St Vincent's Clinical School, 2005. http://handle.unsw.edu.au/1959.4/22484.
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Defining language lateralisation is important to minimise morbidity in patients treated surgically for temporal lobe epilepsy (TLE). Functional magnetic resonance imaging (fMRI) offers a promising, non-invasive, alternative strategy to the Wada test. Here, fMRI has been used to study healthy controls and patients with TLE in order (i) to define language-related activation patterns and their reproducibility; (ii) to compare lateralisation determined by fMRI with that from the Wada test; and (iii) to explore the usefulness of multiple fMRI language paradigms. 18 healthy controls (12 right-handed and 6 left-handed) and 24 pre-operative TLE patients (19 right-handed: 12 left-TLE, 7 right-TLE; 5 left-handed: 2 right-TLE, 3 left-TLE) were studied using fMRI. Four fMRI language paradigms used: phonetic and semantic fluency, and the naming of living and non-living things. The data for all 4 tasks were acquired during a single scanning session on two occasions. All patients also underwent Wada testing. In patients and controls, phonetic and semantic fluency tasks were robustly activating and strongly lateralising. Quantified language-related lateralisation from fMRI verbal fluency data was highly reproducible and concordant with the lateralisation of the Wada test. Both fluency tasks identified patients with atypical language lateralisation, including 4/12 right-handed patients with left-TLE and 4/5 left-handed TLE patients, regardless of the side of epileptic focus. In comparison, the two confrontational naming tasks were not strongly lateralising and did not reliably agree with Wada lateralisation in either 12 right-handed controls or 19 right-handed patients with TLE. However, there was a difference in the pattern of fMRI activation in right-handed pat ients with left-TLE. Left-TLE patients had a more right lateralised network of activation when naming living things relative to non-living things, suggesting that some patients may be at risk of a category specific naming decline for non-living things after left anterior temporal lobectomy. These results demonstrate that non-invasive fMRI measures of languagerelated lateralisation may provide a practical and reliable alternative to invasive testing for pre-surgical language lateralisation in patients with TLE. The high proportion of TLE patients showing atypical language lateralisation suggests considerable plasticity of language representation in the brains of patients with intractable TLE.
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Ma, Rui. "Recommendations Regarding Q-Matrix Design and Missing Data Treatment in the Main Effect Log-Linear Cognitive Diagnosis Model." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/9043.
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Diagnostic classification models used in conjunction with diagnostic assessments are to classify individual respondents into masters and nonmasters at the level of attributes. Previous researchers (Madison & Bradshaw, 2015) recommended items on the assessment should measure all patterns of attribute combinations to ensure classification accuracy, but in practice, certain attributes may not be measured by themselves. Moreover, the model estimation requires large sample size, but in reality, there could be unanswered items in the data. Therefore, the current study sought to provide suggestions on selecting between two alternative Q-matrix designs when an attribute cannot be measured in isolation and when using maximum likelihood estimation in the presence of missing responses. The factorial ANOVA results of this simulation study indicate that adding items measuring some attributes instead of all attributes is more optimal and that other missing data treatments should be sought if the percent of missing responses is greater than 5%.
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Karboyan, Serge. "Dedicated design of experiments and experimental diagnostic tools for accurate reliability investigations on AlGaN/GaN high electron mobility transistors (HEMTs)." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/4019/.
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Le développement intensif et rapide des dispositifs HEMT à base de nitrure de gallium a été largement favorisé par les qualités intrinsèques du matériau pour proposer des performances élevées (haute puissance, haute fréquence. . . ) et pour autoriser un fonctionnement en environnement extrêmement sévère (fluctuations thermiques, brouillage, tenues aux radiations ionisantes. . . ) par rapport aux technologies concurrentes plus traditionnelles (Si, GaAs. . . ). À ce jour, les dispositifs HEMTs AlGaN/GaN sont considérés comme une alternative prometteuse pour remplacer la technologie GaAs, et se positionnent comme d'excellents candidats pour des applications d'électronique de puissance, pour les applications TVSAT, des stations de base terrestres et des systèmes radar à large bande de fréquence (bande L à W), et pour les applications civiles et militaires. Cependant, il reste à lever certains verrous concernant des problèmes de fiabilité de ces dispositifs, qui affectent la durée de vie élevée attendue ; l'amélioration de la robustesse de ces technologies reste une phase critique à étudier malgré les progrès déjà réalisés. Plusieurs paramètres de fabrication affectent la fiabilité, tels que la passivation de la surface, le plateau de champ, le procédé de dépôt de la grille. Il est bien connu que l'étude de la fiabilité est complexe et ne pourra jamais être totalement accomplie, cependant les limites escomptées pour une exploitation raisonnable des filières GaN laissent entrevoir la possibilité de réels progrès dans ce domaine pour assoir le positionnement de ces technologies vis à vis des solutions concurrentes. Ce manuscrit de thèse présente les outils de diagnostic et les procédures de mesures associées développés pour mieux comprendre les mécanismes de dégradation sous-jacents de ces dispositifs. Les mesures électriques DC et pulsées à différentes températures sont présentées en premier lieu. Pour obtenir des informations au niveau microscopique sur la fluctuation des porteurs et des défauts dans les zones actives et passives du dispositif, des mesures de bruit basse fréquence sont effectuées sur les courant de grille et de drain sous différentes configurations : la diode seule (drain en l'air) et le transistor en régime saturé. Une technique électro-optique, l'OBIRCh (Optical Beam Induced Resistance Change technique), est aussi appliquée sur les mêmes composants : cette technique apporte d'autres informations quant à l'intégrité du composant (fluctuations de courant), et vient corroborer nos hypothèses sur l'activation de mécanismes piezoélectriques dans les zones fortement polarisées du composant. Toutes ces techniques non-destructives permettent des analyses croisées. Un modèle original de la diode Schottky a été établi pour tenir compte de certains défauts d'homogénéité à l'intérieur du contact de grille à l'interface entre la diode Schottky et la couche semi-conductrice supérieure. D'autres résultats originaux ont été trouvés à partir des mesures de bruit basse fréquence concernant la localisation des défauts actifs et leur évolution suite à l'application d'un stress électrique et thermique (HTRB, HTOL,. . . ). Les analyses électriques (pulsées et transitoires) des phénomènes de retard à la commande (grille ou drain) sont partiellement corrélées aux analyses du bruit basse fréquences des courant de grille et de drain pour identifier les mécanismes sous-jacents de dégradations. Dernièrement, une ébauche de plan d'expérience (DOE) est proposée dans le cadre de notre travail, qui complètera celui mis en œuvre dans le cadre du projet ANR REAGAN impliquant tous les partenaires : des règles et des procédures expérimentales sont identifiées pour s'assurer que les données expérimentales sont fiables (i. E. Reflètent statistiquement le comportement réel du dispositif)Intensive and rapid development of GaN-based HEMT devices has been largely promoted by their extreme attraction and intrinsic capabilities for proposing high performances (high power and PAE, high frequency, moderate HF noise. . . ) and for operating under different extreme conditions and harsh environment (thermal fluctuations, jamming, ionizing radiations. . . ) over more traditional competitive technologies (Si, GaAs). More than ever, AlGaN/GaN HEMTs are considered as promising technology to replace the GaAs, and an excellent candidate for power electronics applications, for TVSAT applications, terrestrial base stations and radar transceivers operating over large frequency band (from L to W-band) for both civil and military applications. However, some remaining problems concerning the reliability of the devices affect the expected elevated lifetime, and the improvement of the robustness of these technologies stay a questionable phase to study despite the progress already made. Several fabrication parameters could impact the reliability such as surface passivation, field plate, gate deposition process (presence of spontaneous and piezoelectrical effects). It is well known that the reliability background is complex and will never be completely accomplished, but the margin between expected theoretical lifetime and results already obtained motivates efforts to give for an improved level of reliability. The following manuscript presents diagnostic tools and associated measurement procedures to better understand the underlying degradation mechanisms of such devices. Electrical DC and pulsed measurements at different temperatures are presented first. To get more microscopic information about the carrier flow and the defects in the active and passive areas of the device, low frequency noise measurements on the gate and drain currents are investigated under open drain (Schottky diode) and when the transistor is biased in saturated region. An electro-optical technique is also applied, called OBIRCh (Optical Beam Induced Resistance Change technique), on the same devices: this technique brings other expertise about the device integrity (current fluctuations). All these non-destructive techniques are cross-correlated. Original Schottky diode models have been established to account for some inhomogeneities within the gate contact at the interface between the Schottky diode and the upper semiconductor layer. Some other original results have been found from Low Frequency Noise measurements concerning the location of the active defects, and their evolution after the application of thermal and electrical stresses (HTRB & HTOL). The electrical (pulsed and transient) analyses of lag effects are correlated to the harmonic low frequency analysis of the current spectral densities to identify the root trapping mechanisms. Lastly, a first Design of Experiment (DOE) is proposed in conjunction with our work, and also within the ANR REAGAN project involving all the partners: experimental rules and procedures are identified to ensure that the experimental data are reliable (i. E. Reflect the actual behavior of the device, with statistical assessment)
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Blodgett, Thomas J. "The reliability and diagnostic validity of clinical manifestations of catheter-associated urinary tract infection in hospitalized adults: a pilot study." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/4579.
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Catheter-associated urinary tract infection is a common clinical condition among hospitalized patients with numerous health and economic implications. With judicious use of indwelling urinary catheters, along with strict adherence to basic infection prevention measures, such as hand hygiene and aseptic technique during catheter insertion, these infections are most often preventable. However, these devices continue to be used inappropriately or unnecessarily, which has led the Center for Medicare and Medicaid Services (CMS), the Centers for Disease Control and Prevention (CDC), and numerous infectious disease professional societies to focus attention on how these infections can be diagnosed, prevented, and managed. Despite these efforts, consensus on how best to identify cases of CAUTI has been elusive.
Perhaps the most widely used guidelines for the diagnosis, prevention, and treatment of CAUTI are those published in 2010 in the American Journal of Infection Control by Hooton and colleagues. These authors are very clear that CAUTI is a problem if, and only if, it is associated with clinical manifestations; the presence of urinary microorganisms alone is not a clear indication for antimicrobial therapy. Moreover, these authors provide a list of accepted clinical manifestations of CAUTI, which are substantially different from those in previous guidelines. Among others, the manifestations listed include: fever, suprapubic tenderness, flank tenderness, and delirium. However, these are supported by expert opinion only, and neither their diagnostic validity nor their inter-rater reliability have been reported in the literature.
The purpose of this study was to examine the diagnostic validity and inter-rater reliability of fever, suprapubic tenderness, flank tenderness, and delirium in hospitalized adult with an indwelling urinary catheter. Briefly, these clinical manifestations were compared against three diagnostic criteria for CAUTI based on microbiologic and molecular methods, and their inter-rater reliability was examined using assessments conducted by three advanced practice nurses.
Because significant microbial growth was only present in two urine samples, the diagnostic validity of these manifestations could not be established. However, it was possible to examine the inter-rater reliability of these manifestations. To summarize these findings, the nurse raters were in perfect agreement with the identification of fever, moderate agreement with the identification of delirium, and fair agreement with the identification of suprapubic tenderness and flank tenderness. With the exception of flank tenderness, these findings are statistically significant, and they provide evidence that nurses can consistently identify the presence and absence of fever, suprapubic tenderness, and delirium in hospitalized patients with indwelling urinary catheters. As CAUTI receives more attention from multiple stakeholders, nurses must take an active role in correctly identifying patients with this condition. However, this study had several limitations, and further research is necessary to understand the overall clinical utility and value of these manifestations in terms of patient outcomes and cost.
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Gavanmeh, Ahmed Mahmud Ahmed. "Development of unified systems of data collection and processing of accelerated tests of complex products." Thesis, Київський національний університет технологій та дизайну, 2018. https://er.knutd.edu.ua/handle/123456789/9688.
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Losik, Len. "Using Telemetry to Measure Equipment Reliability and Upgrading the Satellite and Launch Vehicle Factory ATP." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595730.
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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, NevadaSatellite and launch vehicles continues to suffer from catastrophic infant mortality failures. NASA now requires satellite suppliers to provide on-orbit satellite delivery and a free satellite and launch vehicle in the event of a catastrophic infant mortality failure. A high infant mortality failure rate demonstrates that the factory acceptance test program alone is inadequate for producing 100% reliability space vehicle equipment. This inadequacy is caused from personnel only measuring equipment performance during ATP and performance is unrelated to reliability. Prognostic technology uses pro-active diagnostics, active reasoning and proprietary algorithms that illustrate deterministic data for prognosticians to identify piece-parts, components and assemblies that will fail within the first year of use allowing this equipment to be repaired or replaced while still on the ground. Prognostic technology prevents equipment failures and so is pro-active. Adding prognostic technology will identify all unreliable equipment prior to shipment to the launch pad producing 100% reliable equipment and will eliminate launch failures, launch pad delays, on-orbit infant mortalities, surprise in-orbit failures. Moving to the 100% reliable equipment extends on-orbit equipment usable life.
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Shewell, Justin Reed. "Hearing the Difference: A Computer-Based Speech-Perception Diagnostic Tool for Non-Native Speakers of English." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd456.pdf.
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Noura, Hassan. "Contribution à la commande des systèmes : diagnostic et commande des systèmes soumis à des défauts." Nancy 1, 1993. http://www.theses.fr/1993NAN10208.
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Le bon fonctionnement d'un processeur industriel peut être altéré par la présence d'un ou plusieurs défauts. Dans ce cas, une commande classique peut s'avérer insuffisante pour préserver la sécurité et la fiabilité du système. Il est donc indispensable de déterminer une stratégie de commande capable de tolérer le défaut lorsqu'il apparait ou bien de s'y accommoder. Différentes méthodes d'accommodation aux défauts, existant dans la littérature, ont été présentées dans le premier chapitre de ce mémoire. Dans le deuxième chapitre, deux approches basées sur la stabilisation simultanée de systèmes ont été proposées. L'importance du diagnostic pour résoudre le problème de l'accommodation aux défauts a été présentée au troisième chapitre. Le quatrième chapitre comporte la comparaison entre deux approches d'accommodation qualifiées d'indirectes. Une de ces méthodes a été testée sur un pendule inversé. Dans la cinquième partie, une méthode qualifiée de directe a été proposée. Le sixième chapitre comprend l'étude d'une approche globale applicable aux systèmes de grande dimension qui a été appliquée à un processus thermique
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Rostaing, Gilles. "DIAGNOSTIC DE DÉFAUT DANS LES ENTRAINEMENTS ÉLECTRIQUES." Phd thesis, Grenoble INPG, 1997. http://tel.archives-ouvertes.fr/tel-00909645.
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Cette thèse représente une contribution aux études sur la disponiblité des dispositifs électrotechnique. L'étude présentée vise à définir la méthode de redondance analytique, basée sur l'estimation d'état, la mieux adaptée au diagnostic des entraînements électriques en considérant les défauts de l'ensemble du convertisseur, de la commande et des capteurs. La méthode retenue doit permettre d'obtenir un modèle de diagnostic implantable en temps réel et sans ajout de capteurs supplémentaires. L'application retenue est un entraînement à courant continu commandé en couple. Le chapitre II compare deux modèles analytiques nommés modèles parallèle et permet de retenir un modèle parallèle "découplé" qui permet une bonne détection et une bonne localisation des défauts d'électronique de puissance ainsi que des défauts capteur. Malheureusement les modèles parallèles sont dépendants des entrées perturbatrices du procédé. Les perturbations génèrent donc des fausses alarmes La batterie d'observateur à entrées inconnues mise au point au chapitre III permet de s'affranchir de l'entrée perturbatrice que constitue dans notre cas le couple de charge. Cette technique est moins dépendante, en terme de découplage, du système car l'injection de sortie grace à la matrice de gain permet de disposer de degrés de liberté supplémentaires qui autorisent un réglage des découplages et des sensibilités. Les observateurs (à entrées inconnues) sont donc, à priori, les modèles de diagnostic les mieux adaptés à la à la détection et la localisation de défauts dans les entrainements électriques à courant continu.
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Ertl, Jakub. "Spolehlivost výkonových olejových transformátorů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-234174.
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The doctoral thesis deals with design of non-invasive methods for estimated reliability analysis of power oil transformers. Such procedures also solve two-state and multistate reliability problems together with applying of gained reliability characteristics in planning further operation of these non-rotating electrical machines. Reliability module for diagnostic system, which is developed at the training workplace, is designed in conclusion of this thesis. All the above procedures were verified on data obtained from diagnostic measurements of ten power oil transformers operating in different power plants in the Czech Republic.
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Manseck, Andreas, Christian Pilarsky, Stefan E. Froschermaier, Mario Menschikowski, and Manfred P. Wirth. "Diagnostic Significance of Prostate-Specific Antigen Velocity at Intermediate PSA Serum Levels in Relation to the Standard Deviation of Different Test Systems." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-133947.
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Serial prostate-specific antigen (PSA) measurements (PSA velocity) as an additional instrument to detect prostatic cancer was introduced in 1992. It has previously been reported that PSA increase per year differed in the last 5 years prior to diagnosis in patients with benign prostatic hyperplasia (0.18 ng/ml/year), locally confined (0.75 ng/ml/year) and metastasized (4.4 ng/ml/year) cancer of the prostate (CaP) in contrast to healthy men (0.04 ng/ml/year). The ability of PSA velocity to detect organ-confined CaP in patients with intermediate PSA serum values depends therefore on a reliable and reproducible PSA result. The present study comprised 85 men with PSA values between 3 and 8 ng/ml (Abbott IMx). PSA measurements were repeated with Abbott IMx (n = 85 patients) and Hybritech Tandem-E (n = 59 patients) assays. The PSA serum values differed from one examination to the other from 0.02 to 2.74 ng/ml with the Abbott IMx. Standard deviation amounted to 0.35 ng/ml with the Abbott IMx PSA assay. Using the Hybritech Tandem-E assay, mean standard deviation was 1.15 ng/ml and therefore higher than with the Abbott IMx assay. The difference from one test to the other ranged from 0.05 to 4.05 ng/ml with the Hybritech Tandem-E. Using the Abbott IMx assay, 10.6% of all repeat measurements exceeded 1 ng/ml whereas in the Hybritech Tandem-E assay 62.7% of the second measurements differed >1 ng/ml from the first PSA result. An increase in PSA serum values may therefore be due to intratest variation, physiological day-to-day variation as well as prostatic disease. It is important to notice that the intra-assay variation may be greater than the PSA increase per year in a patient with CaP. Therefore, PSA velocity seems to be of limited valueDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Manseck, Andreas, Christian Pilarsky, Stefan E. Froschermaier, Mario Menschikowski, and Manfred P. Wirth. "Diagnostic Significance of Prostate-Specific Antigen Velocity at Intermediate PSA Serum Levels in Relation to the Standard Deviation of Different Test Systems." Karger, 1998. https://tud.qucosa.de/id/qucosa%3A27551.
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Serial prostate-specific antigen (PSA) measurements (PSA velocity) as an additional instrument to detect prostatic cancer was introduced in 1992. It has previously been reported that PSA increase per year differed in the last 5 years prior to diagnosis in patients with benign prostatic hyperplasia (0.18 ng/ml/year), locally confined (0.75 ng/ml/year) and metastasized (4.4 ng/ml/year) cancer of the prostate (CaP) in contrast to healthy men (0.04 ng/ml/year). The ability of PSA velocity to detect organ-confined CaP in patients with intermediate PSA serum values depends therefore on a reliable and reproducible PSA result. The present study comprised 85 men with PSA values between 3 and 8 ng/ml (Abbott IMx). PSA measurements were repeated with Abbott IMx (n = 85 patients) and Hybritech Tandem-E (n = 59 patients) assays. The PSA serum values differed from one examination to the other from 0.02 to 2.74 ng/ml with the Abbott IMx. Standard deviation amounted to 0.35 ng/ml with the Abbott IMx PSA assay. Using the Hybritech Tandem-E assay, mean standard deviation was 1.15 ng/ml and therefore higher than with the Abbott IMx assay. The difference from one test to the other ranged from 0.05 to 4.05 ng/ml with the Hybritech Tandem-E. Using the Abbott IMx assay, 10.6% of all repeat measurements exceeded 1 ng/ml whereas in the Hybritech Tandem-E assay 62.7% of the second measurements differed >1 ng/ml from the first PSA result. An increase in PSA serum values may therefore be due to intratest variation, physiological day-to-day variation as well as prostatic disease. It is important to notice that the intra-assay variation may be greater than the PSA increase per year in a patient with CaP. Therefore, PSA velocity seems to be of limited value.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Koch, Christoph. "Endoscopic scoring of the tracheal septum in horses : its reliability as a diagnostic tool and clinical relevance for the evaluation of lower airway health in horses /." [S.l.] : [s.n.], 2005. http://www.zb.unibe.ch/download/eldiss/05koch_c.pdf.
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Carstens, Wiehahn Alwyn. "Regression analysis of caterpillar 793D haul truck engine failure data and through-life diagnostic information using the proportional hazards model." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20333.
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Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Physical Asset Management (PAM) is becoming a greater concern for companies in industry today. The widely accepted British Standards Institutes’ specification for optimized management of physical assets and infrastructure is PAS55. According to PAS55, PAM is the “systematic and co-ordinated activities and practices through which an organization optimally manages its physical assets, and their associated performance, risks and expenditures over their life cycle for the purpose of achieving its organizational strategic plan”. One key performance area of PAM is Asset Care Plans (ACP). These plans are maintenance strategies which improve or ensure acceptable asset reliability and performance during its useful life. Maintenance strategies such as Condition Based Maintenance (CBM) acts upon Condition Monitoring (CM) data, disregarding the previous failure histories of an asset. Other maintenance strategies, such as Usage Based Maintenance (UBM), is based on previous failure histories, and does not consider CM data. Regression models make use of both CM data and previous failure histories to develop a model which represents the underlying failure behaviour of the asset under study. These models can be of high value in ACP development due to the fact that Residual Useful Life (RUL) can be estimated and/or the long term life cycle cost can be optimized. The objective of this thesis was to model historical failure data and CM data well enough so that RUL or optimized preventive maintenance instant estimations can be made. These estimates were used in decision models to develop maintenance schedules, i.e. ACPs. Several regression models were evaluated to determine the most suitable model to achieve the objectives of this thesis. The model found to be most suitable for this research project was the Proportional Hazards Model (PHM). A comprehensive investigation on the PHM was undertaken focussing on the mathematics and the practical implementation thereof. Data obtained from the South African mining industry was modelled with the Weibull PHM. It was found that the developed model produced estimates which were accurate representations of reality. These findings provide an exciting basis for the development of futureWeibull PHMs that could result in huge maintenance cost savings and reduced failure occurrences.
AFRIKAANSE OPSOMMING: Fisiese Bate Bestuur (FBB) is besig om ’n groter bekommernis vir maatskappye in die bedryf te word. Die Britse Standaarde Instituut se spesifikasie vir optimale bestuur van fisiese bates en infrastruktuur is PAS55. Volgens PAS55 is FBB die “sistematiese en gekoördineerde aktiwiteite en praktyke wat deur ’n organisasie optimaal sy fisiese bates, hul verwante prestasie, risiko’s en uitgawes vir die doel van die bereiking van sy organisatoriese strategiese plan beheer oor hul volle lewensiklus te bestuur”. Een Sleutel Fokus Area (SFA) van FBB is Bate Versorgings Plan (BVP) ontwikkeling. Hierdie is onderhouds strategieë wat bate betroubaarheid verbeter of verseker tydens die volle bruikbare lewe van die bate. Een onderhoud strategie is Toestands Gebasseeerde Onderhoud (TGO) wat besluite baseer op Toestand Monitering (TM) informasie maar neem nie die vorige falingsgeskiedenis van die bate in ag nie. Ander onderhoud strategieë soos Gebruik Gebasseerde Onderhoud (GGO) is gebaseer op historiese falingsdata maar neem nie TM inligting in ag nie. Regressiemodelle neem beide TM data en historiese falings geskiedenis data in ag ten einde die onderliggende falings gedrag van die gegewe bate te verteenwoordig. Hierdie modelle kan baie nuttig wees vir BVP ontwikkeling te danke aan die feit dat Bruikbare Oorblywende Lewe (BOL) geskat kan word en/of die langtermyn lewenssilus koste geoptimeer kan word. Die doelwit van hierdie tesis was om historiese falingsdata en TT data goed genoeg te modelleer sodat BOL of optimale langtermyn lewensiklus kostes bepaal kan word om opgeneem te word in BVP ontwikkeling. Hierdie bepalings word dan gebruik in besluitnemings modelle wat gebruik kan word om onderhoud skedules op te stel, d.w.s. om ’n BVP te ontwikkel. Verskeie regressiemodelle was geëvalueer om die regte model te vind waarmee die doel van hierdie tesis te bereik kan word. Die mees geskikte model vir die navorsingsprojek was die Proporsionele Gevaarkoers Model (PGM). ’n Omvattende ondersoek oor die PGM is onderneem wat fokus op die wiskunde en die praktiese implementering daarvan. Data is van die Suid-Afrikaanse mynbedryf verkry en is gemodelleer met behulp van die Weibull PGM. Dit was bevind dat die ontwikkelde model resultate geproduseer het wat ’n akkurate verteenwoordinging van realiteit is. Hierdie bevindinge bied ’n opwindende basis vir die ontwikkeling van toekomstige Weibull Proporsionele Gevaarkoers Modelle wat kan lei tot groot onderhoudskoste besparings en minder onverwagte falings.
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Škrobánek, Martin. "Diagnostický systém papírenského stroje." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417858.
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This master thesis deals with the technical diagnostics, focusing mainly on vibration diagnostics. This problematice is described in the first part of this work on a theoretical level. The next part describes the paper machine, diagnostic system and the measuring points are classified into databases. The practical part of this work consists of a proposal for the methodology of vibration diagnostics for a paper machine, the procedure for measuring and evaluating the measured values. Part of the work is also a practical example of the measurement of the central cylinder, on which the procedure is tested, and the compilation of new limit values.
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Lebranchu, Alexis. "Analyse de données de surveillance et synthèse d'indicateurs de défauts et de dégradation pour l'aide à la maintenance prédictive de parcs de turbines éoliennes." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT082/document.
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Le secteur de l’énergie éolienne est en pleine expansion depuis les 10 dernières années. Le nombre et la taille des éoliennes ont été multipliés, ce qui accroît la difficulté et la criticité de la maintenance, et impose aux industriels de passer d’une maintenance corrective et systématique à une maintenance conditionnelle et prédictive. L'objectif de ces travaux est de développer des indicateurs de dégradation, en utilisant les données numériques fournies par le SCADA, disponibles à faible coût mais enregistrées à une faible fréquence d'échantillonnage (10 min) dans un objectif de suivi de production. Une analyse bibliographique approfondie des travaux réalisés sur la surveillance de parcs éoliens à partir de données SCADA montre que deux types d’approches sont généralement proposés. Les méthodes dites mono-turbines où un modèle de comportement d’une turbine est appris sur des périodes de bon fonctionnement, à partir duquel il est possible de créer des résidus mesurant la différence entre la valeur prédite par le modèle et la mesure en ligne, qui servent d’indicateurs de défaut. Les modèles mono-turbines ont la particularité d’utiliser des variables provenant de la même turbine du parc. Les deuxièmes méthodes, dites multi-turbines, sont des méthodes où l'effet parc et la similarité entre machines sont utilisés. Là où les recherches les plus récentes proposent principalement de créer des courbes de performances pour chaque machine du parc pendant une période de temps et de comparer ces courbes entre elles, nous faisons la proposition originale de combiner les deux approches et de comparer les résidus mono-turbines à une référence parc traduisant le comportement majoritaire des turbines du parc. Nous validons de manière extensive ces indicateurs en analysant leurs performances sur une base de données composée d’enregistrements de variables SCADA d’une durée de 4 ans sur un parc de 6 machines. Nous proposons aussi des critères de performances pertinents permettant d’évaluer de manière réaliste les gains et éventuels surcoûts que généreraient ces indicateurs s’ils étaient intégrés dans un outil de maintenance. Ainsi, nous montrons que le taux d’interventions inutiles associées à des fausses alarmes produites par les indicateurs de défaut, et qui provoquent un surcoût très important pour l’entreprise, peut être fortement diminué par la fusion d’indicateurs mono-turbines que nous proposons, tout en conservant une avance à la détection suffisante pour planifier la mise en place d’interventions par les équipes de maintenanceThe wind energy sector has rapidly gown in the last 10 years. The number and the size of wind turbines have multiplied, which increases the difficulty and the criticality of the maintenance, and forces the wind turbine industry to change from a corrective and systematic maintenance to a conditional and predictive maintenance. The objective of this research is to develop failure indicators using numerical SCADA data, available at a low price but with a very low sampling frequency (10 min), in order to make online monitoring.A thorough bibliographical analysis on the surveillance of wind farms using SCADA data shows that two types of approaches are usually suggested. The first approach, called mono-turbine, where a good behaviour model of a turbine is learnt over unfaulty periods. With this approach, it is possible to create residuals measuring the difference between the predicted value by the model and the on-line measure, which serves as failure indicators. The mono-turbine models have the peculiarity in that they use variables coming from the same turbine as the farms. The second approach, called multi-turbine, are methods where the similarity between machines is used. Where the most recent researches mostly suggest creating performance curves for every machine on the farm during a period of time and comparing these curves between each other, we make the original proposal to combine both approaches and compare mono-turbine residuals with a farm reference representing the behaviour of the turbines of the farm.We validate in an extensive way those failure indicators by analysing their performances on a database made up of SCADA variable recordings of a duration of 4 years on a windfarm of 6 machines. We also propose relevant performance criteria allowing an estimation in a realistic way of the gains and possible additional costs which would generate these indicators if they were integrated into a tool of maintenance. Therefore, we show that the rate of useless interventions associated with false alarms produced by the failure indicators, which cause a heavy additional cost for the company, can be strongly decreased by the mono-turbines indicators merging that we propose, while preserving a sufficient detection time for the maintenance teams to plan interventions
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Luong, Marie. "Conception optimale de l'architecture d'un systeme d'instrumentation sous contraintes de diagnostic, de fiabilité et de disponibilité." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL155N.
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L’objectif de ce mémoire concerne, d'une part, l'analyse structurelle et quantitative d'un processus et, d'autre part, la conception optimale d'une architecture d'instrumentation permettant de définir la position, le nombre et la précision des capteurs. Cette conception doit satisfaire à de nombreuses contraintes dont les principales sont la disponibilité de la valeur des variables nécessaires, la détectabilité et l'isolabilité des capteurs défaillants, la précision de l'estimation, le coût, la fiabilité et la disponibilité du systeme d'instrumentation. Pour ce qui est l'analyse structurelle et quantitative, nous avons développé des méthodes permettant de caractériser le processus selon le critère d'observabilité, le degré de redondance des variables, la détectabilité et l'isolabilité des capteurs défaillants, la précision de l'estimation de l'état du processus, la fiabilité et la disponibilité de son systeme d'instrumentation. Quant à la conception optimale d'un systeme d'instrumentation, elle a été résolue en trois étapes: i) définir la position et le nombre de capteurs sous contraintes d'observabilité, de degré de redondance, de détectabilité et d'isolabilité des capteurs défaillants, de non-mesurabilité et d'obligation de mesurer des variables. En utilisant les cycles et la formulation en termes de programmation linéaire en nombres entiers, une solution optimale est proposée soit en minimisant le coût à fiabilité imposée, soit en maximisant la fiabilité à coût imposé, ii) déterminer la précision des capteurs de façon à garantir une précision imposée de l'estimation, en se basant sur un algorithme à itération directe, iii) déterminer le taux de réparation des capteurs pour obtenir une disponibilité donnée pour le systeme d'instrumentation. Ces méthodes ont été testées sur une partie d'une plate-forme pétrolière de la société ELF
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Nascimento, Denise Antunes Do. "A preliminary assessment of a framework for the allocation of comprehensive primary dental services." Thesis, University of the Western Cape, 2010. http://hdl.handle.net/11394/3795.
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Magister Public Health - MPHSummary:The aim of this study was to produce a preliminary assessment of the DRAF by determining its face validity, testing reliability and usability of its diagnostic classification tool, and to produce a set of preliminary recommendations on the viability of the DRAF before it is released for use within the Family Health Programme.
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Losik, Len. "Using Telemetry to Measure Equipment Mission Life on the NASA Orion Spacecraft for Increasing Astronaut Safety." International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581640.
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ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, CaliforniaThe surprise failure of two NASA Space Shuttles and the premature failures of satellite subsystem equipment on NASA satellites are motivating NASA to adopt an engineering discipline specifically developed for preventing surprise equipment failures. The NASA Orion spacecraft is an Apollo module-like capsule planned to replace the NASA Space Shuttle reusable launch vehicle for getting astronauts to space and return to the earth safely as well as a crew escape vehicle stored at the ISS. To do so, NASA is adopting a non-Markov reliability paradigm for measuring equipment life based on the prognostic and health management program on the Air Force F-35 Joint Strike Fighter. The decision is based on the results from the prognostic analysis completed on the Space Shuttle Challenger and Columbia that identified the information that was present but was ignored for a variety of reasons prior to both accidents. The goal of a PHM is to produce equipment that will not fail prematurely and includes using predictive algorithms to measure equipment usable life. Equipment with transient behavior, missed by engineering analysis is caused from accelerated of parts will fail prematurely with 100% certainty. With the processing speed of today's processors, transient behavior is caused from at least one part suffering from accelerated aging. Transient behavior is illustrated in equipment telemetry in a prognostic analysis but not in an engineering analysis. Telemetry is equipment performance information and equipment performance has been used to increase reliability, but performance is unrelated to equipment remaining usable life and so equipment should be failing prematurely. A PHM requires equipment telemetry for analysis and so analog telemetry will be available from all Orion avionics equipment. Replacing equipment with a measured remaining usable life of less than one year will stop the premature and surprise equipment failures from occurring during future manned and unmanned space missions.
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Losik, Len. "Using Telemetry to Measure Equipment Mission Life on the NASA Orion Spacecraft for Increasing Astronaut Safety." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595658.
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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, NevadaThe surprise failure of two NASA Space Shuttles and the premature failures of satellite subsystem equipment on NASA satellites are motivating NASA to adopt an engineering discipline that uses telemetry specifically developed for preventing surprise equipment failures. The NASA Orion spacecraft is an Apollo module-like capsule planned to replace the NASA Space Shuttle reusable launch vehicle for getting astronauts to space and return to the earth safely as well as a crew escape vehicle stored at the ISS. To do so, NASA is adopting a non-Markov reliability paradigm for measuring equipment life based on the prognostic and health management program on the Air Force F-35 Joint Strike Fighter. The decision is based on the results from the prognostic analysis completed on the Space Shuttle Challenger and Columbia that identified the information that was present but was ignored for a variety of reasons. The goal of a PHM is to produce equipment that will not fail prematurely. It includes using predictive algorithms to measure equipment usable life. Equipment with transient behavior caused from accelerated of parts will fail prematurely with 100% certainty. For many decades, it was believed that test equipment and software used to in testing and noise from communications equipment were the cause of most transient behavior. With the processing speed of today's processors, transient behavior is caused from at least one part suffering from accelerated aging. Transient behavior is illustrated in equipment telemetry in a prognostic analysis. Telemetry is equipment performance information and equipment performance has been used to increase reliability, but performance is unrelated to equipment remaining usable life and so equipment should be failing prematurely. A PHM requires equipment telemetry for analysis and so analog telemetry will be available from all Orion avionics equipment. Replacing equipment with a measured remaining usable life of less than one year will stop the premature and surprise equipment failures from occurring during future manned and unmanned space missions.
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Jiříček, Petr. "Bezpečnost technických systémů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228673.
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The work deals with the safety of technological systems and can be divided into two main thematic units. The attention in the first theoretic unit is paid to aspects that affect the safety of technological systems during their technical life. It describes, together with elementary norms and acts solving the products safety, the most important principles for creating and analysing the safety. It clarifies the origin of company’s risk management, part of its quality management, mentions the faults in which products can be found and also describes the failures which have the biggest effect on these faults and of course on the safety too. Attention is further paid to the reliability analysis, as the tool that helps to create the products safety in the pre-manufacturing phase and also to technical diagnostic, as the tool to keep the safety in after-manufacturing phase. The second practical unit arithmetically analyses the safety of two high-voltage transformers. For that it was used the database of real operation numerical values that were gained during diagnostic investigations on these transformers. In addition it describes mentioned diagnostics methods and gives the new procedure for analyse of transformers’ safety by criteria matrix and weighted sum approach. The main contribution of the work can be considered the checkout and the evaluation of this procedure for use in elaboration of high-voltage transformers diagnostic values for analyzing their safety.
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Gandibleux, Jean. "Contribution à l'évaluation de sûreté de fonctionnement des architectures de surveillance/diagnostic embarquées. Application au transport ferroviaire." Phd thesis, Université de Valenciennes et du Hainaut-Cambresis, 2013. http://tel.archives-ouvertes.fr/tel-00990970.
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Dans le transport ferroviaire, le coût et la disponibilité du matériel roulant sont des questions majeures. Pour optimiser le coût de maintenance du système de transport ferroviaire, une solution consiste à mieux détecter et diagnostiquer les défaillances. Actuellement, les architectures de surveillance/diagnostic centralisées atteignent leurs limites et imposent d'innover. Cette innovation technologique peut se matérialiser par la mise en oeuvre d'architectures embarquées de surveillance/diagnostic distribuées et communicantes afin de détecter et localiser plus rapidement les défaillances et de les valider dans le contexte opérationnel du train. Les présents travaux de doctorat, menés dans le cadre du FUI SURFER (SURveillance active Ferroviaire) coordonné par Bombardier, visent à proposer une démarche méthodologique d'évaluation de la sûreté de fonctionnement d'architectures de surveillance/diagnostic. Pour ce faire, une caractérisation et une modélisation génériques des architectures de surveillance/diagnostic basée sur le formalisme des Réseaux de Petri stochastiques ont été proposées. Ces modèles génériques intègrent les réseaux de communication (et les modes de défaillances associés) qui constituent un point dur des architectures de surveillance/diagnostic retenues. Les modèles proposés ont été implantés et validés théoriquement par simulation et une étude de sensibilité de ces architectures de surveillance/diagnostic à certains paramètres influents a été menée. Enfin, ces modèles génériques sont appliqués sur un cas réel du domaine ferroviaire, les systèmes accès voyageurs des trains, qui sont critiques en matière de disponibilité et diagnosticabilité.