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Reliability Assessment of a Power Grid with Customer Operated Chp Systems Using Monte Carlo SimulationManohar, Lokesh Prakash 01 January 2009 (has links) (PDF)
This thesis presents a method for reliability assessment of a power grid with distributed generation providing support to the system. The distributed generation units considered for this assessment are Combined Heat and Power (CHP) units operated by individual customers at their site. CHP refers to the simultaneous generation of useful electric and thermal energy. CHP systems have received more attention recently due to their high overall efficiency combined with decrease in costs and increase in reliability. A composite system adequacy assessment, which includes the two main components of the power grid viz., Generation and Distribution, is done using Monte Carlo simulation. The State Duration Sampling approach is used to obtain the operating history of the generation and the distribution system components from which the reliability indices are calculated. The basic data and the topology used in the analysis are based on the Institution of Electrical and Electronics Engineers - Reliability Test System (IEEE-RTS) and distribution system for bus 2 of the IEEE-Reliability Busbar Test System (IEEE-RBTS). The reliability index Loss of Energy Expectation (LOEE) is used to assess the overall system reliability and the index Average Energy Not Supplied (AENS) is used to assess the individual customer reliability. CHP reliability information was obtained from actual data for systems operating in New England and New York. The significance of the results obtained is discussed.
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Predicting consultation durations in a digital primary care settingÅman, Agnes January 2018 (has links)
The aim of this thesis is to develop a method to predict consultation durations in a digital primary care setting and thereby create a tool for designing a more efficient scheduling system in primary care. The ultimate purpose of the work is to contribute to a reduction in waiting times in primary care. Even though no actual scheduling system was implemented, four machine learning models were implemented and compared to see if any of them had better performance. The input data used in this study was a combination of patient and doctor features. The patient features consisted of information extracted from digital symptom forms filled out by a patient before a video consultation with a doctor. These features were combined with doctor's speed, defined as the doctor's average consultation duration for his/her previous meetings. The output was defined as the length of the video consultation including administrative work made by the doctor before and after the meeting. One of the objectives of this thesis was to investigate whether the relationship between input and output was linear or non-linear. Also the problem was formulated both as a regression and a classification problem. The two problem formulations were compared in terms of achieved accuracy. The models chosen for this study was linear regression, linear discriminant analysis and the multi-layer perceptron implemented for both regression and classification. After performing a statistical t-test and a two-way ANOVA test it was concluded that no significant difference could be detected when comparing the models' performances. However, since linear regression is the least computationally heavy it was suggested for future usage until it is proved that any other model achieves better performance. Limitations such as too few models being tested and flaws in the data set were identified and further research is encouraged. Studies implementing an actual scheduling system using the methodology presented in the thesis is recommended as a topic for future research. / Syftet med denna uppsats är att utvärdera olika verktyg för att prediktera längden på ett läkarbesök och därmed göra det möjligt att skapa en mer effektiv schemaläggning i primärvården och på så sätt minska väntetiden för patienterna. Även om inget faktiskt schemaläggningssystem har föreslagits i denna uppsats så har fyra maskininlärningsmodeller implementerats och jämförts. Syftet med detta var bland annat att se om det var möjligt att dra slutsatsen att någon av modellerna gav bättre resultat än de andra. Den indata som använts i denna studie har bestått dels av symptomdata insamlad från symptomformulär ifylld av patienten före ett videomöte med en digital vårdgivare. Denna data har kombinerats med läkarens genomsnittliga mötestid i hens tidigare genomförda möten. Utdatan har definierats som längden av ett videomöte samt den tid som läkaren har behövt för administrativt arbete före och efter själva mötet. Ett av målen med denna studie var att undersöka som sambandet mellan indata och utdata är linjärt eller icke-linjärt. Ett annat mål var att formulera problemet både som ett regressionsproblem och som ett klassifikationsproblem. Syftet med detta var att kunna jämföra och se vilken av problemformuleringarna som gav bäst resultat. De modeller som har implementerats i denna studie är linjär regression, linjär diskriminationsanalys (linear discriminant analysis) och neurala nätverk implementerade för både regression och klassifikation. Efter att ha genomfört ett statistiskt t-test och en två-vägs ANOVA-analys kunde slutsatsen dras att ingen av de fyra studerade modellerna presterade signifikant bättre än någon av de andra. Eftersom linjär regression är enklare och kräver mindre datorkapacitet än de andra modellerna så dras slutsatsen att linjär regression kan rekommenderas för framtida användning tills det har bevisats att någon annan modell ger bättre resultat. De begränsningar som har identifierats hos studien är bland annat att det bara var fyra modeller som implementerats samt att datan som använts har vissa brister. Framtida studier som inkluderar fler modeller och bättre data har därför föreslagits. Dessutom uppmuntras framtida studier där ett faktiskt schemaläggningssystem implementeras som använder den metodik som föreslås i denna studie.
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La durée de sommeil et le risque du cancer de l'ovaireMarquis, Flavie 12 1900 (has links)
Introduction : Des variations de la durée de sommeil ont été associées à des perturbations biologiques pouvant affecter le risque de cancer. Seulement quatre études ont examiné la relation entre la durée de sommeil et le risque de cancer de l'ovaire et ont mené à des résultats inconsistants. Aussi, ces études ont considéré une seule mesure de la durée de sommeil collectée tardivement durant la vie adulte, potentiellement après la fenêtre étiologique d'exposition pertinente.
Objectifs : Nous voulions étudier la relation entre 1) la durée de sommeil moyenne durant la vie adulte ainsi que 2) la durée de sommeil par période de la vie adulte et le risque du cancer de l'ovaire. Nous voulions aussi estimer l'association entre la durée de sommeil moyenne et le risque du cancer de l'ovaire selon le comportement tumoral (invasif/borderline) et selon le type de tumeurs invasives (Type I/Type II). Enfin, nous désirions évaluer si cette association était modifiée par des difficultés à s'endormir ou par l'usage d'hormonothérapie substitutive (HTS) parmi les femmes ménopausées.
Méthodes : Les données sur les habitudes de vie et d'autres facteurs ont été collectées dans une étude cas-témoins basée sur la population réalisée à Montréal entre 2011 et 2016 (465 cas et 855 témoins). Les participantes ont rapporté leur durée de sommeil pour les périodes suivantes : 20-29, 30-39, 40-49, 50-59 ans et durant les 2 dernières années. À partir de ces données, nous avons calculé la durée de sommeil moyenne par nuit durant la vie adulte. Avec la régression logistique non-conditionnelle multivariée, nous avons estimé les rapports de cotes (OR) et les intervalles de confiance à 95 % (IC95%) de la relation entre la durée de sommeil et le cancer de l'ovaire.
Résultats : Par rapport à une durée de sommeil moyenne durant la vie adulte de 7-8 h/nuit, les ORs (IC95%) étaient 1,03 (0,72-1,48), 0,98 (0,75-1,27) et 1,59 (1,05-2,40) pour <7 h, 8-9 h, et ≥9 h respectivement. Les ORs pour une durée de ≥9 h durant différentes périodes de la vie adulte suggéraient aussi une augmentation du risque, mais celle-ci était moins marquée que pour la durée de sommeil moyenne. Pour une durée de sommeil moyenne de ≥9 h, l'augmentation du risque était similaire entre les tumeurs ayant comportement invasif ou borderline; toutefois, parmi les tumeurs invasives, cette augmentation était plus forte pour les tumeurs Type I que du Type II. Enfin, les ORs pour une durée de sommeil moyenne de ≥9 h semblaient être modifiés par le fait d'avoir eu des difficultés à s'endormir, mais moins par l'usage d'HTS parmi les femmes ménopausées.
Conclusion : Nos résultats suggèrent qu'une longue durée de sommeil durant la vie adulte pourrait être associée avec le risque du cancer de l'ovaire et que son effet cumulatif serait plus important. / Introduction : Variations in sleep duration have been linked to biological disruptions, which may affect cancer risk. For ovarian cancer, only four studies have examined sleep duration in relation to risk, with inconsistent findings. Also, these studies only analyzed a single measure of sleep collected in later adulthood, potentially after the etiologically relevant time window of exposure.
Objectives : We wanted to study the relationship between 1) average sleep duration over the adult life as well as 2) sleep duration in different periods of the adult life and ovarian cancer risk. We also wanted to estimate the association between average sleep duration and the risk of ovarian cancer according to tumor behavior (invasive/borderline) and type of invasive tumors (Type I/ Type II). Finally, we wanted to evaluate if this association was modified by having had difficulties falling asleep or the use of hormone replacement therapy (HRT) among postmenopausal women.
Methods : Data on lifestyle and other factors were collected in a population-based case-control study conducted in Montreal between 2011 and 2016 (465 cases and 855 controls). Participants reported their sleep duration for the following life periods: 20-29, 30-39, 40-49, 50-59 years old and during the last 2 years, from which we computed the average nightly sleep duration over the adult life. With multivariable unconditional logistic regression, we estimated odds ratios (OR) and 95 % confidence intervals (CI) sleep duration and ovarian cancer risk.
Results : Compared to an average sleep duration in adulthood between 7-8 h/night, the ORs (95%CI) were 1.03 (0.72-1.48), 0.98 (0.75-1.27) and 1.59 (1.05-2.40) for <7 h, 8-9 h, and ≥9 h, respectively. The ORs for ≥9 h during different life periods also suggested an increased risk, though it was less pronounced than for average sleep duration. For an average sleep duration of ≥9 h, the increase in risk did not differ between tumors with invasive or borderline behavior; however, among invasive tumors, this increase in risk was greater for Type I than Type II tumors. Finally, the ORs for an average sleep duration of ≥9 h seemed to be modified by having had difficulties falling asleep, but less so by the use of HRT among postmenopausal women.
Conclusion : The results suggest long sleep in adulthood may be associated with ovarian cancer risk, and that its cumulative effect might be more important.
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Vaccination and Antibody Testing in CatsEgberink, Herman, Frymus, Tadeusz, Hartmann, Katrin, Möstl, Karin, Addie, Diane D., Belak, Sandor, Boucraut-Baralon, Corine, Hofmann-Lehmann, Regina, Lloret, Albert, Marsilio, Fulvio, Penissi, Maria Grazia, Tasker, Severine, Thiry, Etienne, Truyen, Uwe, Hosie, Margaret J. 27 October 2023 (has links)
Vaccines protect cats from serious diseases by inducing antibodies and cellular immune
responses. Primary vaccinations and boosters are given according to vaccination guidelines provided
by industry and veterinary organizations, based on minimal duration of immunity (DOI). For certain
diseases, particularly feline panleukopenia, antibody titres correlate with protection. For feline
calicivirus and feline herpesvirus, a similar correlation is absent, or less clear. In this review, the
European Advisory Board on Cat Diseases (ABCD) presents current knowledge and expert opinion
on the use of antibody testing in different situations. Antibody testing can be performed either in
diagnostic laboratories, or in veterinary practice using point of care (POC) tests, and can be applied
for several purposes, such as to provide evidence that a successful immune response was induced
following vaccination. In adult cats, antibody test results can inform the appropriate re-vaccination
interval. In shelters, antibody testing can support the control of FPV outbreaks by identifying
potentially unprotected cats. Antibody testing has also been proposed to support decisions on
optimal vaccination schedules for the individual kitten. However, such testing is still expensive and
it is considered impractical to monitor the decline of maternally derived antibodies.
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Loneliness During COVID-19 and its Association with Eating Habits and 24-Hour Movement Behaviours in a Sample of Canadian AdolescentsTandon, Saniya 29 August 2023 (has links)
Background: Loneliness, a feeling of distress, has aggravated due to the COVID-19 pandemic lockdowns and reduced social interactions. The objective of this study was to explore whether increased loneliness due to the COVID-19 pandemic was associated with various eating and activity behaviours in adolescence, a critical period for the development of lasting lifestyle habits.
Methods: In this cross-sectional study, we used self-reported data from 43,588 and 40,521 Canadian adolescents aged 12-19 years (collected between November 2020 and June 2021) for eating habits and the 24-hour movement behaviours, respectively. Binary and multinomial logistic regression were used to predict the odds of various lifestyle behaviours among adolescents with increased loneliness due to the COVID-19 pandemic.
Results: We found higher odds of skipping breakfast [boys: OR 1.41 (95% CI: 1.33, 1.50), girls: OR 1.64 (95% CI: 1.56, 1.74)], fast food consumption [1-2 days in the past week: girls - OR: 1.14 (95% CI: 1.08, 1.21); ≥3 days in the past week: boys - 1.12 (95% CI: 1.02, 1.24), girls - OR: 1.42 (95% CI: 1.29, 1.57)], not meeting screen time [boys: OR 1.43 (95% CI: 1.24, 1.66), girls: OR 1.72 (95% CI: 1.54, 1.92)], and sleep duration guidelines [boys: OR 1.38 (95% CI: 1.28, 1.48), girls: OR 1.36 (95% CI: 1.27, 1.45)] among adolescents that reported increased loneliness due to the pandemic (versus those in the decreased/stayed the same loneliness group).
Conclusion: Future longitudinal studies in adolescents are needed to confirm the directionality of these associations. It is important to raise awareness of these findings among public health practitioners, policymakers, physicians, schools and parents to promote healthier eating habits and increase adherence to the 24-hour movement behaviours. Recovery efforts post-pandemic are needed to reduce loneliness levels to support adolescent social health and establish healthy behavioural habits across the lifespan.
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The association between physical activity parameters and olfactory functionNamiranian, Khoosheh 12 1900 (has links)
Le système olfactif a un impact significatif sur la qualité de vie. Une diminution de l'odorat peut influencer la santé physique et mentale des individus, or l’activité physique (AP) pourrait améliorer la fonction olfactive. Cette thèse vise à déterminer l'association entre AP et l'olfaction et si la durée, la fréquence et le volume de l’AP d’intensité moyenne à élevée pouvaient être liés à la fonction olfactive chez l'adulte.
Les données (n = 3527) ont été extraites de l'enquête américaine National Health and Nutrition Examination Survey (NHANES) de 2013-2014. L'étude comprenait des participants qui ont rempli à la fois le questionnaire autodéclaré sur le niveau d’AP et des tests d'odeur (chocolat, fraise, raisin, oignon, fumée, gaz naturel, cuir et savon). L'association entre l'olfaction et les paramètres d’AP a été évaluée à l'aide de corrélations et de régressions logistiques, rapportées ici sous forme de d'intervalles de confiance (IC) à 95 % et de rapport de cotes (RC). La valeur p≤0,05 était considérée comme statistiquement significative.
En analysant l'association entre les paramètres de l'AP et le score olfactif total, il a été montré une corrélation positive avec la durée, la fréquence de l'AP modérée et la fréquence de l'AP vigoureuse, ainsi que le volume total de l'AP (tous p≤ 0,05). La durée, (intervalles de 10 min/jour), une fréquence (jour/semaine) et un volume (METs*h/semaine) plus élevés d'AP modérée étaient associés à une plus grande capacité à détecter les odeurs de raisin [1,002< RCs <1,047, IC95 % (1,000 -1,082), p=0,007]. La fréquence des AP modérées était positivement associée à la capacité à identifier les odeurs de fumée [RC =1,074, IC 95% (1,019-1,131), p=0,008] et de cuir [RC =1,060, IC 95% (1,019-1,103), p= 0,004]. De plus, la fréquence des AP vigoureuses était positivement associée à la détection de l'odeur de raisin [RC = 1,002, IC 95 % (1,000-1,005), p = 0,028]. D'après ces résultats, les paramètres du PA sont liés à la capacité de détection de certaines odeurs, principalement pour l’AP modérée. Cependant, il faut considérer que l'effet constant de l'AP sur les chances de détecter correctement les odeurs est son meilleur de 7.4%. Par conséquent, ces résultats pourront être utilisés par d'autres chercheurs et kinésiologues pour explorer comment améliorer les troubles olfactifs à l'avenir. En ce sens, l'AP d'intensité modérée pourrait particulièrement être recommandée pour la prévention et le traitement des certains troubles olfactifs. / The olfactory system has a significant impact on the quality of life. A decrease in the sense of smell may influence individuals’ physical and mental health, and physical activity (PA) might improve olfactory function. This thesis aimed to determine the association between PA and olfaction and whether the duration, frequency, and volume of moderate to vigorous PA could be related to the olfactory function in adults.
The data (n=3527) were extracted from the U.S. National Health and Nutrition Examination Survey (NHANES) 2013-2014. The study included participants who completed both self-reported PA questionnaire and smell tests (chocolate, strawberry, grape, onion, smoke, natural gas, leather, and soap). The association between olfaction and PA parameters was assessed using correlations and logistic regressions, reported here as Odds-Ratio (OR) and 95% confidence intervals (CI). P-value ≤0.05 was considered statistically significant.
In analyzing the association between PA parameters and total smell score showed a positive correlation with the duration, frequency of moderate and frequency of vigorous PA, as well as PA total volume (all p≤ 0.05). Higher duration (bouts of 10min/day), frequency (day/week), and volume (METs*h/week) of moderate PA was associated with a higher ability to detect the smells of grapes [1.002<ORs<1.047, CI95% (1.000-1.082), p=0.007]. The frequency of moderate PA was positively associated with the capacity to identify smoke [OR =1.074, CI 95% (1.019-1.131), p=0.008] and leather [OR =1.060, CI 95% (1.019-1.103), p=0.004] odors. Furthermore, the frequency of vigorous PA was positively associated with the detection of grape smell [OR =1.002, CI 95% (1.000-1.005), p=0.028]. As a result of these findings, PA parameters are associated with the ability to detect some odors, mostly moderate PA. However, it should be considered that the constant effect of PA on the chance of correctly detecting the smells is his best at 7.4%. Therefore, these results could be used by other researchers and kinesiologists to improve olfactory disorders in the future. Moderate-intensity PA could especially be recommended for the prevention and treatment of some olfactory disorders.
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Commitment, the Crucible of Peace Agreements : Quantitative study on how providing for peacekeeping operations affects the duration of peace agreements in intra-state conflictsEnderstad, Linus January 2024 (has links)
Recurring conflicts are a common occurrence as most contemporary intra-state conflicts are recured old conflicts. This is the reality within peace and conflicts studies and a well studied phenomenon. Yet despite deaced of reserach, there still exist subjects wihtin the construction n of peace agreements that have not been studied that might reduce the recurrence of conflict. This thesis explores the effect of providing for a peacekeeping operation within a peace agreement. Based on theories of credible commitment the proposed hypothesis is that peace agreements that provide for a peacekeeping operation are mot durable than those that do not. Using the Uppsala Conflict Data Programs (UCDP) peace agreement dataset, which records peace agreements from 1975 to 2021, a quantitative study will be performed. A bivariable and multivariable regression as well as a T-test and Hazard-test will be used to explore this relationship. The hypothesis does not find support wihtin the statistical evidence that providing for a peacekeeping operation affects the duration of the agreement. However, the thesis still finds important implications for the construction of peace agreements.
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ELUCIDATING BIOPHYSICAL CUES CONDUCIVE TO TARGETED MULTIPOTENT CELL DIFFERENTIATIONMcBride, Sarah January 2008 (has links)
No description available.
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Sleep and Health Related Quality of Life in Children with Cardiac DiseaseBrubaker, Jennifer Ann January 2011 (has links)
No description available.
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Evaluation of the Response of Perpetual Pavement at Accelerated Pavement Loading Facility: Finite Element Analysis and Experimental InvestigationHernandez, Jaime A. 22 September 2010 (has links)
No description available.
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