Segui questo link per vedere altri tipi di pubblicazioni sul tema: Stress detection and management.
Tesi sul tema "Stress detection and management"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Stress detection and management".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Keryakos, Youssef. "Detection and management of stressful situations to help the blind persons in their daily lives". Electronic Thesis or Diss., Bourgogne Franche-Comté, 2024. http://www.theses.fr/2024UBFCD043.
Testo completoAbstract (sommario):
Le stress, une expérience commune à diverses activités humaines, affecte de manière significative la vie quotidienne des individus, en particulier ceux ayant des déficiences visuelles. Défini comme un état de tension physique ou mentale, le stress provient de situations qui induisent frustration, nervosité ou colère. Le Syndrome d'Adaptation Générale (SAG) décrit la réponse du corps au stress, englobant les phases d'Alarme, de Résistance et d''Epuisement, et implique la libération d'hormones de stress comme le cortisol et l'adrénaline. Identifier et gérer le stress chez les personnes aveugles est particulièrement difficile en raison de leur dépendance aux indices sensoriels non visuels pour la navigation.Les personnes aveugles éprouvent un stress accru lors de la navigation en raison de l'incapacité à voir les obstacles et les changements dans leur environnement. Ce stress est exacerbé dans les environnements extérieurs et intérieurs inconnus ou complexes, où les aides traditionnelles à la navigation, telles que les GPS et les images satellites, sont inefficaces. Les résultats de notre travail ont établi que la présence d'obstacles et la complexité des itinéraires de navigation sont directement corrélées à des niveaux de stress accrus. Malgré le développement de divers outils d'assistance, tels que les compas en braille et les cannes blanches, ces solutions sont souvent insuffisantes pour fournir un soutien complet.En réponse à ces défis, nous proposons un nouveau système de navigation hybride conçu pour aider les personnes aveugles en intégrant la détection du stress en temps réel et une aide à l'orientation lors de la navigation. Notre système utilise une canne blanche intelligente équipée d'un réseau de capteurs biologiques pour surveiller les indicateurs physiologiques du stress, notamment la fréquence cardiaque, la conductance de la peau et l'activité musculaire. En analysant ces biosignaux, le système vise à identifier les situations induisant du stress et à recommander des itinéraires de navigation moins stressants.Le système proposé répond aux défis de la navigation en extérieur et en intérieur. Pour les environnements extérieurs, le système génère des indices de difficulté et de stress des itinéraires, permettant aux utilisateurs de choisir et de suivre le chemin le moins stressant. La détection en temps réel des obstacles est réalisée grâce à des techniques avancées de traitement d'images, et les utilisateurs reçoivent des indications vocales pour naviguer efficacement. Pour les environnements intérieurs, où les données GPS et satellites sont indisponibles, le système utilise la réalité augmentée (RA) et un système de gestion de contenu (SGC) pour créer des cartes virtuelles basées sur des images de plans d'étage. Des codes QR dans l'espace intérieur permettent aux utilisateurs de charger et d'interagir avec ces cartes virtuelles via une application mobile.L'intégration de la détection du stress en temps réel et du soutien à la navigation représente un avancement significatif dans la technologie d'assistance. En réduisant le stress et en améliorant l'efficacité de la navigation, le système vise à améliorer la qualité de vie des personnes malvoyantes. Les recherches futures se concentreront sur l'évaluation des performances du système, l'analyse des retours des utilisateurs et le raffinement de la technologie pour garantir une fonctionnalité optimale et la satisfaction des utilisateurs. Cette approche améliore non seulement l'indépendance, mais fournit également une expérience de navigation plus gérable et moins stressante pour les utilisateurs aveuglesStress is a universal human experience that has a substantial impact on people's day-to-day functioning, particularly for those who are visually impaired. Stress is characterized as a condition of tension, either bodily or mental, that results from events that cause anxiety, agitation, or frustration. The alarm, resistance, and exhaustion phases of the body's reaction to stress are outlined by the General Adaptation Syndrome (GAS), which also includes the release of stress hormones like cortisol and adrenaline. Blindness makes it especially difficult to recognize and manage stress, as blind people rely on non-visual sensory signals to navigate.Being unable to notice barriers and changes in their surroundings causes blind persons to experience more stress when navigating. In unfamiliar or complicated outdoor and indoor environments, when conventional navigational aids like GPS and satellite images are useless, this stress is increased. Our research's findings have demonstrated a clear relationship between higher stress levels and the difficulty of navigation routes and the existence of barriers. Even with the invention of numerous assistive devices, such as white canes and braille compasses, these solutions frequently fail to offer complete assistance.We address these issues by putting forth a novel hybrid navigation system that combines real-time stress detection with navigation assistance to help blind people. Our method makes use of a smart white cane that is outfitted with a network of biosensors to keep an eye on physiological stress markers including heart rate, muscular activity, and skin conductance. The system's goal is to identify stressful conditions and suggest less stressful navigation routes by evaluating these biosignals.The suggested solution tackles navigational issues in both indoor and outdoor environments. The system creates stress and route difficulty indices for outdoor surroundings, enabling users to select and follow the least stressful path. Advanced image processing techniques are used to detect obstacles in real-time, and verbal commentary is provided to users to help them navigate safely. The technology uses augmented reality (AR) and a content management system (CMS) to build virtual maps based on floor plan photos for indoor environments where GPS and satellite data are not available. Thanks to a mobile application, users can load and interact with these virtual maps by scanning QR codes located within the indoor space.Real-time stress detection and navigation support are integrated into the system, which is a major leap in assistive technology. The system's goal is to make navigation more efficient and less stressful for people who are blind or visually impaired. Subsequent studies will concentrate on assessing the system's effectiveness, examining user input, and improving the technology to guarantee peak performance and user contentment. For blind individuals, this method not only increases independence but also makes navigation easier and less stressful
2
Ostovar, Alireza. "Business process drift: Detection and characterization". Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/127157/1/Alireza_Ostovar_Thesis.pdf.
Testo completoAbstract (sommario):
This research contributes a set of techniques for the early detection and characterization of process drifts, i.e. statistically significant changes in the behavior of business operations, as recorded in transactional data. Early detection and subsequent characterization of process drifts allows organizations to take prompt remedial actions and avoid potential repercussions resulting from unplanned changes in the behavior of their operations.
3
Gaur, Sudhanshu. "Interference management in MIMO networks". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24769.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: Mary Ann Ingram; Committee Member: Geoffrey Li; Committee Member: Gregory Durgin; Committee Member: Prasad Tetali; Committee Member: Raghupathy Sivakumar.
4
Xu, Cheng. "Scalable Validation of Data Streams". Doctoral thesis, Uppsala universitet, Avdelningen för datalogi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-291530.
Testo completoAbstract (sommario):
In manufacturing industries, sensors are often installed on industrial equipment generating high volumes of data in real-time. For shortening the machine downtime and reducing maintenance costs, it is critical to analyze efficiently this kind of streams in order to detect abnormal behavior of equipment. For validating data streams to detect anomalies, a data stream management system called SVALI is developed. Based on requirements by the application domain, different stream window semantics are explored and an extensible set of window forming functions are implemented, where dynamic registration of window aggregations allow incremental evaluation of aggregate functions over windows. To facilitate stream validation on a high level, the system provides two second order system validation functions, model-and-validate and learn-and-validate. Model-and-validate allows the user to define mathematical models based on physical properties of the monitored equipment, while learn-and-validate builds statistical models by sampling the stream in real-time as it flows. To validate geographically distributed equipment with short response time, SVALI is a distributed system where many SVALI instances can be started and run in parallel on-board the equipment. Central analyses are made at a monitoring center where streams of detected anomalies are combined and analyzed on a cluster computer. SVALI is an extensible system where functions can be implemented using external libraries written in C, Java, and Python without any modifications of the original code. The system and the developed functionality have been applied on several applications, both industrial and for sports analytics.
5
Protsenko, I. M. "Stress management". Thesis, Видавництво СумДУ, 2012. http://essuir.sumdu.edu.ua/handle/123456789/26022.
Testo completoAbstract (sommario):
Stress management refers to a wide spectrum of techniques and psychotherapies aimed at controlling a person's levels of stress, especially chronic stress, usually for the purpose of improving everyday functioning.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/26022
6
Lau, Shing-hon. "Stress Detection for Keystroke Dynamics". Research Showcase @ CMU, 2018. http://repository.cmu.edu/dissertations/1208.
Testo completoAbstract (sommario):
Background. Stress can profoundly affect human behavior. Critical-infrastructure operators (e.g., at nuclear power plants) may make more errors when overstressed; malicious insiders may experience stress while engaging in rogue behavior; and chronic stress has deleterious effects on mental and physical health. If stress could be detected unobtrusively, without requiring special equipment, remedies to these situations could be undertaken. In this study a common computer keyboard and everyday typing are the primary instruments for detecting stress. Aim. The goal of this dissertation is to detect stress via keystroke dynamics – the analysis of a user’s typing rhythms – and to detect the changes to those rhythms concomitant with stress. Additionally, we pinpoint markers for stress (e.g., a 10% increase in typing speed), analogous to the antigens used as markers for blood type. We seek markers that are universal across all typists, as well as markers that apply only to groups or clusters of typists, or even only to individual typists. Data. Five types of data were collected from 116 subjects: (1) demographic data, which can reveal factors (e.g., gender) that influence subjects’ reactions to stress; (2) psychological data, which capture a subject’s general susceptibility to stress and anxiety, as well as his/her current stress state; (3) physiological data (e.g., heart-rate variability and blood pressure) that permit an objective and independent assessment of a subject’s stress level; (4) self-report data, consisting of subjective self-reports regarding the subject’s stress, anxiety, and workload levels; and (5) typing data from subjects, in both neutral and stressed states, measured in terms of keystroke timings – hold and latency times – and typographical errors. Differences in typing rhythms between neutral and stressed states were examined to seek specific markers for stress. Method. An ABA, single-subject design was used, in which subjects act as their own controls. Each subject provided 80 typing samples in each of three conditions: (A) baseline/neutral, (B) induced stress, and (A) post-stress return/recovery-to-baseline. Physiological measures were analyzed to ascertain the subject’s stress level when providing each sample. Typing data were analyzed, using a variety of statistical and machine learning techniques, to elucidate markers of stress. Clustering techniques (e.g., K-means) were also employed to detect groups of users whose responses to stress are similar. Results. Our stressor paradigm was effective for all 116 subjects, as confirmed through analysis of physiological and self-report data. We were able to identify markers for stress within each subject; i.e., we can discriminate between neutral and stressed typing when examining any subject individually. However, despite our best attempts, and the use of state-of-the-art machine learning techniques, we were not able to identify universal markers for stress, across subjects, nor were we able to identify clusters of subjects whose stress responses were similar. Subjects’ stress responses, in typing data, appear to be highly individualized. Consequently, effective deployment in a realworld environment may require an approach similar to that taken in personalized medicine.
7
Madjar, Nicole, e Filip Lindblom. "Machine Learning implementation for Stress-Detection". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280897.
Testo completoAbstract (sommario):
This project is about trying to apply machine learning theories on a selection of data points in order to see if an improvement of current methodology within stress detection and measure selecting could be applicable for the company Linkura AB. Linkura AB is a medical technology company based in Linköping and handles among other things stress measuring for different companies employees, as well as health coaching for selecting measures. In this report we experiment with different methods and algorithms under the collective name of Unsupervised Learning, to identify visible patterns and behaviour of data points and further on we analyze it with the quantity of data received. The methods that have been practiced on during the project are “K-means algorithm” and a dynamic hierarchical clustering algorithm. The correlation between the different data points parameters is analyzed to optimize the resource consumption, also experiments with different number of parameters are tested and discussed with an expert in stress coaching. The results stated that both algorithms can create clusters for the risk groups, however, the dynamic clustering method clearly demonstrate the optimal number of clusters that should be used. Having consulted with mentors and health coaches regarding the analysis of the produced clusters, a conclusion that the dynamic hierarchical cluster algorithm gives more accurate clusters to represent risk groups were done. The conclusion of this project is that the machine learning algorithms that have been used, can categorize data points with stress behavioral correlations, which is usable in measure testimonials. Further research should be done with a greater set of data for a more optimal result, where this project can form the basis for the implementations.Detta projekt handlar om att försöka applicera maskininlärningsmodeller på ett urval av datapunkter för att ta reda på huruvida en förbättring av nuvarande praxis inom stressdetektering och åtgärdshantering kan vara applicerbart för företaget Linkura AB. Linkura AB är ett medicintekniskt företag baserat i Linköping och hanterar bland annat stressmätning hos andra företags anställda, samt hälso-coachning för att ta fram åtgärdspunkter för förbättring. I denna rapport experimenterar vi med olika metoder under samlingsnamnet oövervakad maskininlärning för att identifiera synbara mönster och beteenden inom datapunkter, och vidare analyseras detta i förhållande till den mängden data vi fått tillgodosett. De modeller som har använts under projektets gång har varit “K-Means algoritm” samt en dynamisk hierarkisk klustermodell. Korrelationen mellan olika datapunktsparametrar analyseras för att optimera resurshantering, samt experimentering med olika antal parametrar inkluderade i datan testas och diskuteras med expertis inom hälso-coachning. Resultaten påvisade att båda algoritmerna kan generera kluster för riskgrupper, men där den dynamiska modellen tydligt påvisar antalet kluster som ska användas för optimalt resultat. Efter konsultering med mentorer samt expertis inom hälso-coachning så drogs en slutsats om att den dynamiska modellen levererar tydligare riskkluster för att representera riskgrupper för stress. Slutsatsen för projektet blev att maskininlärningsmodeller kan kategorisera datapunkter med stressrelaterade korrelationer, vilket är användbart för åtgärdsbestämmelser. Framtida arbeten bör göras med ett större mängd data för mer optimerade resultat, där detta projekt kan ses som en grund för dessa implementeringar.
8
Uggla, Gabriel. "Pause — Stress Management". Thesis, Umeå universitet, Designhögskolan vid Umeå universitet, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171773.
Testo completoAbstract (sommario):
Stress affects us all more or less, but over the last decade people who suffer from severe stress and its symptomshas increased considerably. Women are especially affected, with absence from Swedish workplaces due tostress growing 370% between 2011—2019. As of 2020, stress is treated when we experience symptoms suchas anxiety, panic attacks or insomnia, but it is more sustainable to prevent stress than treating it in terms ofmoney, time, health and effort.Through collaboration with people affected by stress, psychiatrists & researchers specialized on stress, anddesigners from different disciplines, the topic of stress was explored and researched to create a conceptualsolution that could be able to help users manage their stress better.“Pause” is the result of this work. It is a conceptual product ecosystem consisiting of an application andwatch that facilitates monitoring and management of stress in day-to-day scenarios, in order to prevent andreduce stress.
9
Kangas, Persson Emil. "Stress Management for Pilots". Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-35606.
Testo completoAbstract (sommario):
A human brain is capable to achieve great things, to endure heavy stress and to calculate complex problems. What happens when it fails to do so? Is there anything that could be done to prevent this from happening? Is it possible to help a pilot in command manage his or her stress during flight by measuring finger temperature, skin conductance, ECG and heart rate variations? This thesis study processes that can help pilots manage high stress with simple tools such as closing their eyes and taking a few deep breaths. To determine when the calming measures are needed and to evaluate potential effects, all the signal data stated above are used combined with scoring of every participant performance. The statistical methods used involves an ANOVA-test and mean value calculations. The results were also analyzed using CBR to get a better understanding of the results and to not only rely on statistical methods. The thesis is limited to a minor study of 10 student pilots participating in two sessions with a heavy workload departure in a simulator. The test did result in a small difference between the two sessions which pointed at the calming measures giving a slight improvement for the pilots. However, when ANOVA was applied it showed that the difference between the two sessions was not a significant one. This could be due to several reasons; the pilots were not used to the calming measures and because of this felt more stressed when trying to use the calming measures as well. There might have been a difference if calming measures were included into pilot training already from the beginning. Another reason might be because this is only a minor study and the difference was not apparent on so few participants. In future research, however, there might be a breakthrough on how to handle stress in a cockpit environment involving similar sensors.
10
Bonner, Tanya. "Stress, coping, and corporate stress management : a review". Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50108.
Testo completoAbstract (sommario):
Thesis (MA)--University of Stellenbosch, 2004.Hierdie artikel bied 'n teoretiese oorsig van stres en streshantering in die korporatiewe omgewing. Die artikel begin met 'n kort oorsig van die historiese ontwikkeling van die streskonsep, gevolg deur 'n kort bespreking van die konsep streshantering. Vervolgens word verskeie faktore wat tot stres in die werkplek bydra, in oënskou geneem. Dit word opgevolg deur 'n bespreking van stres wat kenmerkend is van bestuursposisies en 'n kort oorsig van onlangse navorsing oor streshanteringsprogramme. Sommige van die probleme wat met navorsing oor streshanteringsprogramme ondervind word, word kortliks oorweeg. Die artikel word afgesluit met 'n poging om, op grond van gepubliseerde bevindings, te illustreer watter stresverminderende intervensies doeltreffend is en watter nie.
AFRIKAANSE OPSOMMING: Hierdie artikel bied 'n teoretiese oorsig van stres en streshantering in die korporatiewe omgewing. Die artikel begin met 'n kort oorsig van die historiese ontwikkeling van die streskonsep, gevolg deur 'n kort bespreking van die konsep streshantering. Vervolgens word verskeie faktore wat tot stres in die werkplek bydra, in oënskou geneem. Dit word opgevolg deur 'n bespreking van stres wat kenmerkend is van bestuursposisies en 'n kort oorsig van onlangse navorsing oor streshanteringsprogramme. Sommige van die probleme wat met navorsing oor streshanteringsprogramme ondervind word, word kortliks oorweeg. Die artikel word afgesluit met 'n poging om, op grond van gepubliseerde bevindings, te illustreer watter stresverminderende intervensies doeltreffend is en watter nie.
11
Unruh, Ellen M. "Heat stress detection and mitigation in feedlot cattle". Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38179.
Testo completoAbstract (sommario):
Master of Science in Biomedical SciencesDepartment of Clinical Sciences
Robert L. Larson
Bradley J. White
Feedlot cattle frequently endure high environmental temperature-humidity index conditions in the summer months within cattle feeding regions of North America. Heat stress develops when the total heat gain (combined effects of environmental and metabolic factors) exceeds an animal’s heat loss capabilities. The objective of my research was evaluating heat mitigation strategies and developing a practical method to identify animals that are of greatest risk of heat stress; thus improving animal welfare and performance. A number of heat abatement strategies have been utilized in US feedlots including shade, sprinklers, nutritional modifications, and misters. A literature review was performed using published journal articles demonstrated significant benefits of providing shade to feedlot cattle. Sprinkling the pen surface may be just as beneficial as sprinkling or misting cattle. Sprinkling the ground not only cooled the ground which increased the thermal gradient between lying cattle and the ground, but also provided increased thermal conductivity and better heat flow down that gradient. A study was performed to develop a noninvasive, remotely applied, practical method to identify animals at risk for heat stress. Infrared thermography images were obtained during the morning hours and pant scores obtained in the afternoon hours. Data mining techniques were employed to evaluate accuracy of potential classification methods to identify heat stress events in the afternoon based on the known morning data. Using infrared technology as a diagnostic test was not accurate for predicting heat stress events in the study presented. Finally a retrospective study of Kansas feedlot performance, medical and weather data was performed. Findings indicate that diagnostic counts of bovine respiratory disease are associated with elevated ambient temperature two days prior. In conclusion, heat stress in beef feedlot animals is an important area of research. Heat mitigation methods such as shade have been proven to be effective at reducing heat stress in beef feeder cattle. Further research is needed to evaluate the use of infrared technology to predict heat stress events in the feedlot setting.
12
Kiriakos, Bernard. "Detection of lexical stress in English isolated words". Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61710.
Testo completo
13
Crane, Andrew John. "The spectral detection of salt stress in cotton". Thesis, University of Portsmouth, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292358.
Testo completo
14
Guriel, Jennifer L. "Detection of coached malingering of posttraumatic stress disorder". Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3324.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains iv, 71 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 29-32).
15
Rastgoo, Mohammad Naim. "Driver stress level detection based on multimodal measurements". Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/134144/1/Mohammad%20Naim%20Rastgoo%20Thesis_Redacted.pdf.
Testo completoAbstract (sommario):
Successful driver performance is fundamental in preventing vehicle crashes. Stress can negatively affect driver performance and significantly increase the risk of a crash. Therefore, an in-vehicle warning system for driver stress levels is needed to continuously predict dangerous driving situations and proactively alert drivers to ensure safe and comfortable driving. As a result of the recent developments in sensing technologies and context recognition, driver stress can be detected using multimodal measurements. This thesis proposes a general framework for building a driver stress level detection system based on multimodal measurements and adopts different approaches to maximise the performance of the system.
16
Seidel, Jayna G. "Adolescent female stress management curriculum". Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1585967.
Testo completoAbstract (sommario):
The purpose of this curriculum is to help adolescent females navigate the stress they experience during this developmental stage in a safe and effective way. The curriculum aims to increase adolescent females' self-esteem, increase their knowledge of effective communication strategies, and increase their ability to identify support systems in life. The curriculum includes eight 1 hour sessions designed to be delivered in a group setting. The curriculum was designed based on a review of the literature and research concerning adolescence, adolescent learning theories, interventions, relational aggression, conflict management, compassion and empathy, healthy relationships, self-esteem, and support systems. Curriculum limitations, implications for social work practice, and recommendations for future curriculums are also discussed.
17
Mead, Amanda M. "Proactive Stress Management for Firefighters". Antioch University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1544913796266512.
Testo completo
18
Stuart, Marta. "Stress Management After a Disaster". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/157093.
Testo completo
19
Harley-McClaskey, Deborah. "Stress Reduction and Time Management". Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/4708.
Testo completo
20
Tanner, Amy Vivien. "Detection and measurement of stress hormones with mass spectrometry". Thesis, University of Greenwich, 2012. http://gala.gre.ac.uk/9155/.
Testo completoAbstract (sommario):
The purpose of this thesis was to develop and validate a liquid chromatography mass spectrometry (LC-MS) method to measure salivary cortisol and testosterone. Furthermore, to use this method to analyse saliva samples collected during an exercise study measuring the hormonal response to acute exercise. The ongoing contribution to knowledge provided by this research is the application of a developed and validated LC-MS method to analysis of cortisol from pre and post exercise saliva samples, and evaluation of the cortisol and testosterone response to three different training sessions; including an interval session (INT), tempo run (TEMP) and aerobic circuit training (CIR). An LC-MS method was developed to measure cortisol and testosterone. The mass spectrometer used was a triple quadrupole BioQ (Waters/Micromass, UK) coupled with a 1200 series HPLC machine (Agilent Technologies, UK). Optimisation of various parameters was undertaken including: cone voltage and capillary voltage, followed by optimisation of liquid chromatography (LC) parameters such as; mobile phase gradient and flow rate. Saliva samples were collected at rest, and hormones measured with the new LC-MS method and ELISA to validate the developed method. Finally, heart rate and salivary and plasma cortisol and testosterone response to acute exercise were tested, to compare the response to different training protocols in runners. Following this, the MS method underwent further validation against ELISA. Results revealed optimum MS parameters were: cone voltage 25 V; capillary voltage 3.5 kV and LM and HM resolution 8 Da. For the LC method, mobile phase flow rate was optimised at 0.1 mL/min, with a gradient profile ranging from 50 to 95% methanol (MeOH), and a run time of 15 minutes. Sample preparation was also considered (solid phase extraction); and wash phase of 10% MeOH, 10 times sample concentration and reconstitution with 80% MeOH were optimised to improve analyte recovery and detection. Comparison of cortisol measured at rest with LC-MS and ELISA (n=22) revealed a correlation between methods (r=0.83, P<0.001). The exercise study showed the INT elicited a higher peak heart rate (172±11) than CIR (148±10) or TEMP trials (163±10). INT also produced a higher RPE (15 ±2) than CIR (13±1) and TEMP (14±2) trials. Salivary cortisol increased at all time points post exercise in INT and remained higher than rest (1.29 ± 0.51 ng/mL) at 60 minutes recovery (3.13 ±1.59 ng/mL). Salivary testosterone increased pre to post exercise in CIR (119.7±39.5 pg/mL to 150.1 ±51.5 pg/mL), TEMP (142.4±76.5 pg/mL to 185.0±49.1 pg/mL) and INT (117.5±23.5 pg/mL to 176.3±46.0 pg/mL) trials. There was also a correlation between cortisol measured in plasma and saliva (r=0.813, p=0.0001). Additionally, comparison of salivary cortisol measurements obtained with mass spectrometry and ELISA (n=85) showed a correlation (r=0.934, p=00001). In conclusion, validation revealed cortisol could be quantfied accurately and precisely with LC-MS. Additionally, INT elicited a higher mean RPE and cortisol response than TEMP or CIR.
21
Nguyen, Nguyet Thi Minh. "Earnings management : detection, application and contagion". Thesis, University of Kent, 2017. https://kar.kent.ac.uk/59823/.
Testo completoAbstract (sommario):
The accounting scandals in the 2000s and 2010s have led to a number of large-scale reforms in financial reporting and corporate governance regulations around the world, and still attract a lot of public debates recently. In that context, the demand for further knowledge on earnings management is very topical. What we have known is earnings management does exist. What we have not known, however, seems still overwhelming. We need to know more about issues such as how earnings management could be detected, to what extent earnings management has an impact on investment decisions, what drives earnings management behaviour etc. The accounting research community has responded to such demand by producing a very large, and still growing, volume of publications on the topic during the last few decades. In fact, earnings management has now been one of the largest strands in the mainstream accounting literature. This thesis aims to make original and important contributions to the literature on earnings management. The main components of the thesis comprise of three empirical chapters which analyse secondary data on the United Kingdom's (the UK hereafter) stock market during the period from 1995 to 2011. The contributions are made on three important and inter-related research strands within the earnings management literature, namely the earnings management detection models, the impact of earnings management on stock market investment, and the spread of earnings management as a corporate decision through board network. The first empirical chapter constructs a signal-based composite index, namely ESCORE, which captures the context of earnings management. Specifically, ESCORE aggregates fifteen individual signals related to earnings management based on prior relevant literature. Empirical results using UK data shows that when ESCORE is higher, firms do manage earnings with greater magnitude and are more likely to be most aggressive using both accruals and real earnings management. Firms which are investigated for financial-statement-related irregularities are also shown to have significantly higher ESCORE. The composite score can be easily applied in practice as well as replicated in subsequent studies, especially in emerging market where small samples technically constrain the use of other existing earnings management detection models. The approach to construct ESCORE is innovative and it only measures the likelihood rather than the magnitude of earnings management. This aspect of ESCORE is important given the growing criticisms that none of the existing earnings management models could actually measure the magnitude of earnings management. Using ESCORE as a measure that captures the general context of earnings management, the second empirical chapter asks if investors rationally price the information contained in such context. Empirical evidence shows that firms with low ESCORE outperform those with high ESCORE by 1.37% per month after controlling for risk loadings on the market, size, book-to-market and momentum factors in up to one year after portfolio formation. The relationship between ESCORE and future returns is still significant, in both economic and statistical terms, after controlling for various other known 'market anomalies', including the size, value-glamour, seasoned equity offer, market irrational reaction to financial distress, balance sheet bloat, profitability and discretionary accruals. This finding is in line with the behavioural explanation that investors tend to ignore the observable context of earnings management under the influence of the well-documented base rate fallacy. This is an original piece of knowledge which makes significant and interesting contributions to the literature on market anomalies. The third and last empirical chapter investigates whether aggressive earnings management practices spread across firms sharing interlocked directors. The evidence shows that if a firm aggressively manages earnings (referred to as a 'contagious firm') via accruals (or production activities and discretionary expenses) manipulation in a year, any firms (referred to as 'exposed firms') which are interlocked with that contagious firm in that year and the two following years are more likely to aggressively manage earnings via accruals (or production activities and discretionary expenses, respectively) manipulation. The contagion effect is found to be more pronounced if the interlocked director is male, older, British, and charged with duties which could influence financial reporting. The contagion effect is robust after controlling for endogeneity issues and common characteristics of the interlocked firms. The evidence presented in this chapter is both original and a significant contribution to our knowledge on the impact of board networks on corporate decisions, a topic which attracts a lot of attention as it fits directly to the process of reforming corporate governance codes to enhance the efficiency and effectiveness of the boards of directors.
22
Guerrier, Sterenn. "High bandwidth detection of mechanical stress in optical fibre using coherent detection of Rayleigh scattering". Electronic Thesis or Diss., Institut polytechnique de Paris, 2022. http://www.theses.fr/2022IPPAT004.
Testo completoAbstract (sommario):
Répondant à une demande croissante de connectivité entre les individus, entre les pays et par conséquent entre les continents, les fibres optiques de télécommunications sont déployées dans le monde entier. Les continents comme les océans sont désormais quadrillés par ces réseaux dont l'importance stratégique n'est plus à démontrer. De manière plus générale, les fibres optiques sont une alternative aux capteurs électrodynamiques de vibrations, avec un atout majeur : la possibilité de détecter et localiser des phénomènes indépendants tout au long de la fibre, bien au-delà de la simple détection de ruptures de fibres et allant jusqu’à la reconnaissance de multiples signatures audio voire de la parole. Cette thèse a pour but d'étudier finement la rétro-diffusion Rayleigh dans les fibres optiques, qui permet de capter de l'information induite par des perturbations mécaniques tout le long d'une fibre. Nous étudions le potentiel des fibres optiques en tant que microphones distribués, en terme de bande passante mécanique et de sensibilité. Nous décrivons le système d'interrogation des capteurs à fibre distribués, et proposons la modélisation d'un tel interrogateur en tenant compte du multiplexage des signaux sur deux axes orthogonaux de polarisation lors de la propagation dans la fibre. Nous étudions la problématique de l'évanouissement dans la fibre : à la fois l'évanouissement de polarisation que nous parvenons à annuler grâce à la méthode d'interrogation Coherent-MIMO, et l'évanouissement cohérent que nous proposons de diminuer en recourant à une interrogation multi-porteuses électronique. Différents résultats de mesure sont également présentés dans cette thèse : nous validons le seuil de distinction du système d'interrogation sur quelques kilomètres de fibre monomodes de télécommunications, puis, sur des dizaines de kilomètres de fibres incluant des câbles déployés, nous validons la pertinence d'un système de captation par segment de fibres dans les réseaux télécom à haut débit, ouvrant ainsi la voie à des systèmes de télémétrie évoluée dédiés aux réseaux optiques de demainTelecommunication fibres are being deployed all over the world, connecting distant people, institutions, companies with an outstanding quality of service in terms of data rate and latency. Their strategic value in terms of global economy and daily life is now undeniable. Monitoring such an infrastructure has become mandatory, and that far beyond the standard case of breaks localization. From a broader standpoint, optical fibres are an alternative to electro-dynamic point sensors, with a strong asset: the capability to detect and localize multiple independent phenomena all along a fibre. Thus, the millions of kilometers of currently deployed optical fibre around the world constitute a huge potential base of sensors. Distributed vibration sensors have a huge potential regarding sensing of dynamic events, detecting of multiple acoustic signatures up to speech signals. In this thesis, we show how distributed optical fibre sensors can be designed on top of telecommunication fibres, namely standard single mode fibres, and we explore their potential in terms of reach, detection threshold, and sensing bandwidth. We present the interrogator systems for distributed fibre sensing and build a dual-polarization numerical model of such an interrogation system and fibre sensor. Secondly, we tackle the coherent fading issue by means of frequency diversity in the digital domain, i.e. directly applicable at the modulation of the interrogation sequences, before entering the optical domain. We developed MIMO-OFDM which retrieves independent channel estimations from a single fibre segment; the estimations are further combined, and the obtained estimations are assessed with regards to the reliability metric. Throughout this thesis, many experimental measurements were conducted, assessing the capabilities of the Coherent-MIMO interrogator on single-mode-fibre sensors in terms of reach, bandwidth, and detection threshold. We also demonstrate the co-propagation of a sensing signal along with high data rate channels, without any impact on the transmitted data, paving the way to the enhanced monitoring and telemetry in deployed telecommunication networks
23
Aigrain, Jonathan. "Multimodal detection of stress : evaluation of the impact of several assessment strategies". Electronic Thesis or Diss., Paris 6, 2016. http://www.theses.fr/2016PA066681.
Testo completoAbstract (sommario):
Il est maintenant largement accepté que le stress joue un rôle important dans les sociétés modernes. Le stress impacte en effet le corps et l'esprit à différents niveaux. De plus, le lien entre stress et maladie a été observé dans plusieurs études. Cependant, il n'y a pas encore de définition consensuelle du stress, et par conséquent il n'y a pas de manière consensuelle de le mesurer. Ainsi, bien que la qualité de la mesure joue un rôle majeur dans la réalisation de solutions robustes de détection du stress, les chercheurs doivent choisir une stratégie de mesure parmi un grand nombre de possibilités. Cette hétérogénéité impacte la validité des comparaisons faites entre les différentes solutions. Dans cette thèse, nous évaluons l'impact de plusieurs stratégies de mesure pour la détection du stress. Dans un premier temps, nous résumons comment différents domaines de recherche définissent et mesurent le stress. Nous décrivons ensuite comment nous avons collecté des données de sujets en situation stressante ainsi que plusieurs mesures du stress. Nous étudions également les liens entre ces différentes mesures. Par la suite, nous présentons les descripteurs comportementaux et physiologiques que nous avons extraits pour nos expériences. Enfin, nous présentons les résultats obtenus concernant l'impact des stratégies de mesure sur 1) la normalisation de données, 2) la performance des descripteurs pour la classification et 3) sur la conception d'algorithmes d'apprentissage automatique. De manière générale, nous défendons l'idée qu'il faut adopter une approche globale pour concevoir une solution de détection du stressIt is now widely accepted that stress plays an important role in modern societies. It impacts the body and the mind at several levels and the association between stress and disease has been observed in several studies. However, there is no consensual definition of stress yet, and therefore there is no consensual way of assessing it either. Thus, although the quality of assessment is a key factor to build robust stress detection solutions, researchers have to choose among a wide variety of assessment strategies. This heterogeneity impacts the validity of comparing solutions among them. In this thesis, we evaluate the impact of several assessment strategies for stress detection. We first review how different fields of research define and assess stress. Then, we describe how we collected stress data along with multiple assessments. We also study the association between these assessments. We present the behavioural and physiological features that we extracted for our experiments. Finally, we present the results we obtained regarding the impact of assessment strategies on 1) data normalization, 2) feature classification performance and 3) on the design of machine learning algorithms. Overall, we argue that one has to take a global and comprehensive approach to design stress detection solutions
24
Maynard, I. W. "Towards effective stress management in sport". Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243085.
Testo completo
25
Crockett, Cedrick D. "Stress Management Treatments among Police Departments". ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/6001.
Testo completoAbstract (sommario):
The police profession is viewed as one of the most stressful occupations in the world. Police officers are responsible for handling calls for service, serving and protecting the community, enforcing laws, and preventing and solving crimes. These responsibilities along with many others can become overwhelming and lead to police stress and trauma. Police stress has been linked to adverse effects on the performances and health of police officers. The purpose of this mixed methods study was to describe the internal and external factors of police stress through their lived experiences as police officers, and the stress management techniques used by police departments to treat police stress. The theoretical framework was based on Kingdon's multiple streams approach. The research questions were designed to examine the factors of police stress and the treatments offered by police departments to help officers manage police stress. Data were collected through surveys and interviews with 15 police officers and 2 human resources department employees from 2 police departments in a southern state. Quantitative results from the surveys were analyzed using Intellectus Statistics software. Qualitative results from the face to face interviews were organized and analyzed using Nvivo 12. The findings indicated that death, time away from family, and trust were main stress factors affecting officers and that Employee Assistance Programs were treatments police departments offer to officers to help manage stress. The implications for social change is improving police officer job performance, the overall mental and physical health of police officers as well as strengthening police-citizen relationships.
26
Nikoci, Besjana <1989>. "Stress Testing for Financial Risk Management". Master's Degree Thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/6935.
Testo completoAbstract (sommario):
The complexity and duration of the financial crisis has led many banks and authorities to question the adequacy of stress testing practices prior to the crisis and their efficiency to cope with rapidly changing circumstances. Stress testing is a process to identify and manage situations that could cause extraordinary losses and it is an important risk management tool that is used by banks as part of their internal risk management. Majority of models make assumptions that do not hold in abnormal markets. Therefore, stress tests are vital for a comprehensive picture of risk. In this thesis we will be introducing basics of stress-testing and elaborate on its models and methodologies.
27
Aigrain, Jonathan. "Multimodal detection of stress : evaluation of the impact of several assessment strategies". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066681/document.
Testo completoAbstract (sommario):
Il est maintenant largement accepté que le stress joue un rôle important dans les sociétés modernes. Le stress impacte en effet le corps et l'esprit à différents niveaux. De plus, le lien entre stress et maladie a été observé dans plusieurs études. Cependant, il n'y a pas encore de définition consensuelle du stress, et par conséquent il n'y a pas de manière consensuelle de le mesurer. Ainsi, bien que la qualité de la mesure joue un rôle majeur dans la réalisation de solutions robustes de détection du stress, les chercheurs doivent choisir une stratégie de mesure parmi un grand nombre de possibilités. Cette hétérogénéité impacte la validité des comparaisons faites entre les différentes solutions. Dans cette thèse, nous évaluons l'impact de plusieurs stratégies de mesure pour la détection du stress. Dans un premier temps, nous résumons comment différents domaines de recherche définissent et mesurent le stress. Nous décrivons ensuite comment nous avons collecté des données de sujets en situation stressante ainsi que plusieurs mesures du stress. Nous étudions également les liens entre ces différentes mesures. Par la suite, nous présentons les descripteurs comportementaux et physiologiques que nous avons extraits pour nos expériences. Enfin, nous présentons les résultats obtenus concernant l'impact des stratégies de mesure sur 1) la normalisation de données, 2) la performance des descripteurs pour la classification et 3) sur la conception d'algorithmes d'apprentissage automatique. De manière générale, nous défendons l'idée qu'il faut adopter une approche globale pour concevoir une solution de détection du stressIt is now widely accepted that stress plays an important role in modern societies. It impacts the body and the mind at several levels and the association between stress and disease has been observed in several studies. However, there is no consensual definition of stress yet, and therefore there is no consensual way of assessing it either. Thus, although the quality of assessment is a key factor to build robust stress detection solutions, researchers have to choose among a wide variety of assessment strategies. This heterogeneity impacts the validity of comparing solutions among them. In this thesis, we evaluate the impact of several assessment strategies for stress detection. We first review how different fields of research define and assess stress. Then, we describe how we collected stress data along with multiple assessments. We also study the association between these assessments. We present the behavioural and physiological features that we extracted for our experiments. Finally, we present the results we obtained regarding the impact of assessment strategies on 1) data normalization, 2) feature classification performance and 3) on the design of machine learning algorithms. Overall, we argue that one has to take a global and comprehensive approach to design stress detection solutions
28
Burman, Hanna, e Julia Mattsson. "Coronastress management : Hur chefer arbetar med stress management under coronakrisen". Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-434260.
Testo completoAbstract (sommario):
Stress är en stigande folksjukdom som kan drabba vem som helst, och inte minst accelerera till följd av rådande covid-19-pandemin. Med anledning av att individer spenderar så pass mycket tid på sitt jobb behöver även arbetsgivare hantera detta. I försök att hantera och förebygga stress kan organisationer och chefer använda sig utav stress management. Stress management omfattas av olika tillvägagångssätt, verktyg och modeller, i syfte att hjälpa arbetsgivare att påverka och hantera stress hos deras anställda. Följande studie ämnar således åt att undersöka hur chefer arbetar med (och eventuellt anpassar) stress management på arbetsplatsen efter de omställningar som coronakrisen orsakat. För att besvara studiens syfte genomfördes tio semistrukturerade intervjuer, baserat på ett strategiskt urval av respondenter. Resultatet av undersökningen visar på att chefer har anpassat sin stress management under pandemin, men på olika sätt. Fem nya stressdrivande faktorer och två nya stresshämmande faktorer har även uppmärksammats av respondenterna till följd av omställningarna.
29
Parsons, Kelley S. "Detection-Action Sequence in Vigilance: Effects on Workload and Stress". Cincinnati, Ohio : University of Cincinnati, 2007. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1177942825.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--University of Cincinnati, 2007.Advisor: Dr. Joel Warm. Title from electronic thesis title page (viewed June 30, 2010). Keywords: Vigilance; Workload; Stress; Detection-Action. Includes abstract. Includes bibliographical references.
30
Docherty, Lorraine. "Molecular detection and gene expression of Campylobacter during stress conditions". Thesis, University of Surrey, 1997. http://epubs.surrey.ac.uk/843004/.
Testo completoAbstract (sommario):
The magnetic immuno-polymerase chain reaction assay (MIPA), was developed for the detection of Campylobacter jejuni and Campylobacter coli initially in milk and chicken products. After 18 hours pre-enrichment the MIPA could detect 420 cfu g-1 of chicken and 63 cfu ml-1 of artificially contaminated milk. MIPA was then applied for the detection of C. jejuni / C. coli in cloacal swabs and in retail poultry, where the sensitivity was found to be comparable to cultural methods. However, results were available significantly faster, within 24 hours compared to the 4-5 days of cultural methods. MIPA was also evaluated as a technique for the detection of "viable but non-culturable" (VBNC) forms in the environment. It was found that there was a reduction in sensitivity for the detection of these non-culturable forms (NCFs) and it was concluded that the MIPA had limited use in their detection. The lack of sensitivity of MIPA for detecting VBNC campylobacters in the environment may indicate that they are either antigenically or genetically distinct from the culturable forms. This result highlights the question of whether these VBNC forms actually represent a viable potentially infectious form of Campylobacter. This question can be answered at a molecular level; promoter activity can be monitored as a representation of viability of the bacterial cell during stress conditions. The promoter activity could be measured using a promoter probe vector. Initially we decided to construct a promoter probe vector which based on the recombinase system of the PI bacteriophage. However, the final construct was unstable and due to the constraints of time we decided to use a pre-existing promoter probe vector pSP73 constructed by Purdy and Park, (1993). This promoter probe vector contains promoterless luxAB genes which induce light emission as a reporter of gene expression. In order to investigate the genetic regulation during the conversion of C. jejuni to non-culturable forms (NCFs), we monitored gene expression during the transformation of C. jejuni into the non-culturable state. The promoterless copy of the luxAB genes was placed under the control of promoter regions of the C. jejuni flaA gene. Transformed C. jejuni was incubated under stress conditions that induce transition to NCFs (Non-culturable forms). Promoter activity, plate counts and direct microscope counts were simultaneously monitored. It was found that during the initial conversion of C. jejuni to NCFs there is an up-regulation of the flaA promoter. This regulation occurs in response to agitation and did not occur in NCFs and indicates that they are functionally non-viable.
31
Goel, Pradeep Kumar. "Hyper-spectral remote sensing for weed and nitrogen stress detection". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82882.
Testo completoAbstract (sommario):
This study investigated the possibility of using data, acquired from airborne multi-spectral or hyper-spectral sensors, to detect nitrogen status and presence of weeds in crops; with the ultimate aim of contributing towards the development of a decision support system for precision crop management (PCM).A 24-waveband (spectrum range 475 to 910 nm) multi-spectral sensor was used to detect weeds in corn (Zea mays L.) and soybean ( Glycine max (L.) Merr.) in 1999. Analysis of variance (ANOVA), followed by Scheffe's test, were used to determine which wavebands displayed significant differences in aerial spectral data due to weed treatments. It was found that the radiance values were mainly indicative of the contribution of weeds to the total vegetation cover in various plots, rather than indicative of changes in radiance of the crops themselves, or of differences in radiance between the weed populations and the crop species.
In the year 2000, a 72-waveband (spectrum range 407 to 949 nm) hyperspectral sensor was used to detect weeds in corn gown at three nitrogen levels (60, 120 and 250 kg N/ha). The weed treatments were: no control of weeds, control of grasses, control of broadleaved weeds and control of all weeds. Imagery was acquired at the early growth, tassel, and fully-mature stages of corn. Hyper-spectral measurements were also taken with a 512-waveband field spectroradiometer (spectrum range 270 to 1072 nm). Measurements were also carried out on crop physiological and associated parameters. ANOVA and contrast analyses indicated that there were significant (alpha = 0.05) differences in reflectance at certain wavebands, due to weed control strategies and nitrogen application rates. Weed controls were best distinguished at tassel stage. Nitrogen levels were most closely related to reflectance, at 498 nm and 671 nm, in the aerial data set. Differences in other wavebands, whether related to nitrogen or weeds, appeared to be dependent on the growth stage. Better results were obtained from aerial than ground-based spectral data.
Regression models, representing crop biophysical parameters and yield in terms of reflectance, at one or more wavebands, were developed using the maximum r2 criterion. The coefficients of determination (r 2) were generally greater than 0.7 when models were based on spectral data obtained at the tassel stage. Models based on normalized difference vegetation indices (NDVI) were more reliable at estimating the validation data sets than were the reflectance models. The wavebands at 701 nm and 839 nm were the most prevalent in these models.
Decision trees, artificial neural networks (ANNs), and seven other classifiers were used to classify spectral data into the weed and nitrogen treatment categories. Success rates for validation data were lower than 68% (mediocre) when training was done for all treatment categories, but good to excellent (up to 99% success) for classification into levels of one or the other treatment (i.e. weed or nitrogen) and also classification into pairs of levels within one treatment. Not one classifier was determined best for all situations.
The results of the study suggested that spectral data acquired from airborne platforms can provide vital information on weed presence and nitrogen levels in cornfields, which might then be used effectively in the development of PCM systems.
32
Allen, H. Joel. "A Behavioral Model for Detection of Acute Stress in Bivalves". Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc277998/.
Testo completoAbstract (sommario):
A behavioral model for acute responses in bivalves, was developed using time series analysis for use in a real-time biomonitoring unit. Stressed bivalves closed their shell and waited for the stressful conditions to pass. Baseline data showed that group behavior of fifteen bivalves was periodic, however, individuals behaved independently. Group behavior did not change over a period of 20 minutes more than 30 percent, however, following toxic exposures the group behavior changed by more than 30 percent within 20 minutes. Behavior was mathematically modeled using autoregression to compare current and past behavior. A logical alarm applied to the behavior model determined when organisms were stressed. The ability to disseminate data collected in real time via the Internet was demonstrated.
33
Wang, Jing. "Detection and characterization of harmful algae by bioluminescent stress fingerprinting". College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1978.
Testo completoAbstract (sommario):
Thesis (M.S.) -- University of Maryland, College Park, 2004.Thesis research directed by: Dept. of Nutrition and Food Science. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
34
Ehe, Kerstin Anna von der. "Detection of stress during the drying process of polymer dispersions". Clausthal-Zellerfeld Papierflieger, 2008. http://d-nb.info/993813410/04.
Testo completo
35
MARINO, Giovanni, Giovanni MARINO e Giovanni MARINO. "Detection of the effects of water stress on woody plants". Doctoral thesis, Università degli studi del Molise, 2014. http://hdl.handle.net/11695/66250.
Testo completoAbstract (sommario):
Climate change is increasing the chronic water scarcity in many world regions, and also in Mediterranean basin. Water is the most limiting resource for plant growth and development where the climate is characterized by high potential evaporation and low and highly variable rainfall during the growing season. Water deficit constraints all the physiological processes involved in photosynthesis. In addition, drought and heat have effects on plats secondary metabolism as the synthesis and the emission of volatile organic compounds (VOCs) that, on global scale, are able to influence the chemical and physical properties of the atmosphere. Therefore, in last years has become important to develop methods enabling the detection and the description of water relations and the physiological responses of plants experiencing water stress, that could allow the monitoring on large scale of the effects of an increasing drought condition on the vegetation.
In the present study phenotyping methods have been applied to monitor water relations, photosynthetic status and physiological responses in woody plants experiencing water stress. The aim of the study was to evaluate the reliability of remote sensing techniques, based on the passive analysis of spectral reflectance, to monitor the water status of plants and different functions that are affected by drought. Thereafter, a new application of these methods was tested for the detection of the indirect estimation of foliar isoprenoid emissions, in order to sense them remotely. In addition, the relationships and the interactions of chemical and hydraulic signals from root to leaves and the emission of VOCs were investigated in a partial root zone drought experiment on Populus nigra saplings.I cambiamenti climatici in corso stanno aumentando la cronica scarsità di acqua in molte regioni del mondo, come anche nel bacino del Mediterraneo. L'acqua è la principale risorsa limitante per la crescita e lo sviluppo delle piante, in aree in cui il clima è caratterizzato da un elevato potenziale di evaporazione e precipitazioni scarse e molto variabili nel corso delle stagioni vegetative. Il deficit idrico vincola tutti i processi fisiologici coinvolti nella fotosintesi. Inoltre, la siccità e la temperatura hanno anche effetti sul metabolismo secondario delle piante, come la sintesi e l’emissione di composti organici volatili (VOC) che, su scala globale, sono in grado di influenzare le proprietà fisiche e chimiche dell'atmosfera. Pertanto, negli ultimi anni è diventato di rilevante importanza sviluppare metodi che consentano l'individuazione e la descrizione delle relazioni idriche e le risposte fisiologiche delle piante sottoposte a stress idrico, che potrebbero consentire il monitoraggio su larga scala degli effetti della condizione crescente di scarsa disponibilità idrica sulla vegetazione. Nel presente studio sono stati applicati metodi di fenotipizzazione per monitorare le relazioni idriche, lo stato della fotosintesi e le risposte fisiologiche di piante legnose sottoposte a stress idrico. Lo scopo dello studio è stato di valutare l'applicabilità di tecniche di telerilevamento, basate sull'analisi passiva della riflettanza spettrale, per monitorare lo stato idrico e le diverse funzioni di piante legnose sottoposte a siccità. Successivamente, una nuova applicazione di questi metodi è stato impiegata per la stima indiretta delle emissioni fogliari di isoprenoidi, al fine di consentirne il rilevamento da remoto. Inoltre sono stati studiati, in un esperimento in condizione di parziale siccità della zona radicale in piante in vaso di Populus nigra, i rapporti e le interazioni esistenti tra i segnali chimici e idraulici dalle radici alle foglie e l'emissione di VOC.
36
Caliboso, Menchie. "Does understanding and adhering to a stress management program affect stress outcomes?" Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10118889.
Testo completoAbstract (sommario):
High prenatal stress and the stress hormone cortisol have been shown to lead to adverse birth outcomes. Yet, few studies have examined the efficacy of prenatal stress management programs on improving prenatal stress and cortisol outcomes, specifically what factors (i.e., participant comprehension and content fidelity) in implementing these programs might influence whether pregnant women obtain improved stress outcomes. This study demonstrated that participant comprehension (i.e., how well a participant understands program material) and content fidelity (i.e., how well instructors adhere to core program components) were not associated with stress and cortisol outcomes among low-income pregnant women enrolled in a stress management program. Future research should investigate whether program characteristics (e.g., cultural norms of the population, skill-learning, or therapeutic-oriented processes) mediate these implementation factors. By understanding multivariate models of implementation factors and program characteristics, health care practitioners can effectively provide the CBSM program to pregnant women across at-risk communities.
37
Suarez-Cano, Gabriela. "Racial and ethnic differences in perceived stress, social support, and stress management". University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1522335867241361.
Testo completo
38
Salain, Samantha Leigh Fields. "Stress Management Training, Gender, Level of Stress, and Coping in Police Officers". ScholarWorks, 2017. https://scholarworks.waldenu.edu/dissertations/3833.
Testo completoAbstract (sommario):
Stress has lasting and sometimes fatal effects on the law enforcement community, which can compromise the well-being of police officers. To date, there is little research on factors that influence the level of stress in police officers. The purpose of this quantitative, correlational study was to investigate the relationship of gender, used coping mechanisms, and levels of organizational and operational stress among police officers who have and have not received stress management training. Bandura's social learning theory and Lazarus and Folkman's theory of cognitive appraisal provided the theoretical foundation. Cross-sectional survey data from a convenience sample of 134 male and female police officers were collected using the Brief Cope, the Operational and Organizational Police Stress Questionnaire, and a demographic survey. An independent samples t test and multiple linear regression analyses were conducted to test the hypotheses. According to study findings, officers who received stress management training demonstrated a higher use of adaptive coping mechanisms compared to those who did not receive training. In addition, gender and use of maladaptive coping predicted level of stress among officers. Evidently, receiving stress management training was useful for these participating police officers, and these findings suggest that the training may have positive demonstrable effects for other police officers. This study promotes positive social change by increasing knowledge and awareness of the value that stress management has in reducing level of stress and use of maladaptive coping in police officers, thus empowering the psychological needs of officers while endorsing public safety at the individual and societal level.
39
Brown, Minda J. "Relationship Between Stress Management Self-Efficacy, Stress Mindset, and Vocational Student Success". ScholarWorks, 2019. https://scholarworks.waldenu.edu/dissertations/7788.
Testo completoAbstract (sommario):
Due to the passage of the Gainful Employment Rule of 2015, for-profit schools must ensure graduate employability, which forces vocational schools to make student success a priority. The concepts of stress mindset from the cognitive activation theory of stress and stress management self-efficacy from social cognitive theory were used in this study to assess the relationship of each to the employability of graduates. This study utilized a nonrandomized convenience sampling method and a multiple logistic regression with categorical dependent/criterion variables (gainful employment versus not) and continuous predictor variables (stress management self-efficacy, stress mindset) to compare the relationships. Stress mindset levels were measured using the stress mindset measure while stress management self-efficacy levels were measured by the stress management self-efficacy measure with 66 participants. The results of this study indicated that while both increased levels of stress management self-efficacy and a positive stress mindset were associated with a significantly increased likelihood of gainful employment, on its own, stress management self-efficacy was a better indicator than was stress mindset, on its own. The implications for positive social change from the results of this study, are a greater understanding of the importance of stress management self-efficacy and a positive stress mindset on the employability of technical school graduates. This knowledge could lead to the creation of improved stress management and stress mindset assistance for technical school students, which could lead to increased employability in these graduates.
40
Anthony, Romy Leigh. "A stress management module for shift workers". Thesis, Cape Peninsula University of Technology, 2006. http://hdl.handle.net/20.500.11838/1748.
Testo completoAbstract (sommario):
Thesis (MTech (Human Resources Management))--Cape Peninsula University of Technology, 2006Many people work shifts because of socio-economic considerations and for them stopping shift work is not a realistic option. Shift work can have a negative impact on the health and well being of workers. The reason for this is that in every individual's body there are many rhythms/cycles, which are designed for daytime work. When these rhythms are disrupted as in nightime work, they need time to adjust so that they may all function as one. These rhythms do not adjust instantaneously; therefore the impact on the body is negative. This in turn, leads to a reduction in performance attentiveness, as well as an increase in the risk of accidents and injuries. Most shift workers do not know how to adjust their lifestyle to minimise the negative effects of working around the clock as companies do not provide the required programmes for their well being, thus increasing the chance of suffering from stress. If this is so, then, not only will the well being of the individual or employee be disrupted, but so too will productivity, as well as the profits of the business. This therefore means that shift work could in the end diminish the economic gain it was designed to create. "A tailor-made shift system should be a compromise between the employer's goals, the wishes of employees, and ergonomic recommendations for the design of shift systems" (Knauth, 1997:21). According to Ahasan (2002:09): "Currently there is little information available in the literature that supports the effective design of shift schedules, which offer effective productivity levels, while maintaining the health and safety of shift workers", It therefore has to be realised that there is no ideal shift system, which is going to fully meet an organisations needs, as well as the well being, social and family needs of each and every single employee within the organisation. Employers and employees can work together in order to learn how to identify and control shift work hazards. Also, employees need to learn how to cope better with the demands of their work schedule. Due to the many disruptions encountered in their personal life, social life and physical well being, the existence of stressrelated illnesses is increased in shift workers. Employers may pick up signs of stress when the following factors are monitored on a regular basis, as well as investigated if and when variances occur:
41
Bracher, Grant Allan. "Detection of nutrient stress in Douglas-fir seedlings using spectroradiometer data". Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30961.
Testo completoAbstract (sommario):
Narrow-band spectral reflectance measurements in the visible and near-infrared region of the spectrum were investigated for the detection of nutrient deficiencies, and estimating the foliar concentrations of nitrogen, phosphorus, sulphur, and total chlorophyll. One-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were treated with 24 nutrient solutions containing nitrogen, phosphorus and sulphur levels ranging from 1 to 400 mg/L. After one growing season, newly matured needles were harvested, spectral reflectance measured from 400 to 1100 nm, and foliar samples analyzed for nutrient and chlorophyll levels.
Several nutrient deficiencies were diagnosed. There were no unique changes in spectral reflectance which could be attributed to a specific nutrient deficiency; rather changes in reflectance were non-specific responses influenced by how varying nutrient levels affected total chlorophyll concentration. All deficiencies caused decreases in total chlorophyll, thus demonstrating the value of total chlorophyll as an indicator of nutrient stress.
Correlation coefficients were calculated describing the degree of association between foliar nitrogen, phosphorus, sulphur and total chlorophyll, and the following spectral parameters: the wavelength of the red edge, percent spectral reflectance at 554 and 630 nm (red rise), and 15 vegetation indices (VIs). VIs were first determined using combinations of spectral reflectances at 480, 554, 800 nm and the wavelength of the red well (674 nm; called red well
VIs), and then recalculated using red rise (called red rise VIs) rather than red well measurements to see if greater correlation with foliar constituents could be obtained. Although the use of red rise measurements in the calculation of VIs 1, 2, 3, 12 and 14 resulted in higher correlation coefficients, differences between coefficients were seldom statistically significant.
Red well and red rise VI15 were most correlated with the needle nitrogen content of individual Douglas-fir, red rise VI10 with phosphorus, and spectral reflectance at 554 nm and red well VI15 with total chlorophyll. These parameters proved useful indicators of relative nitrogen, phosphorus and total chlorophyll content. None of the VIs or other spectral parameters followed the same relationship with foliar sulphur for the sulphur, nitrogen and phosphorus treatments; consequently, none were deemed suitable for sulphur estimation.Forestry, Faculty of
Graduate
42
Brisson, Bruce W. "Stress corrosion crack detection in alloy 600 in high temperature caustic". Thesis, Monterey, California. Naval Postgraduate School, 1996. http://hdl.handle.net/10945/9017.
Testo completoAbstract (sommario):
CIVINSAlloy 600, the material used for pressurized water reactor steam generator tubing, is susceptible to environmentally assisted stress corrosion cracking. Intergranular stress corrosion cracking (IGSCC) attacks the tubes in areas of high residual stress, and in crevice regions. No method has been successfully developed to monitor steam generator tubing in-situ for crack initiation and growth. Essentially all available published IGSCC crack growth data for alloy 600 is based on non-tubing material. Although it is very likely that the current data base is applicable to tubing processing, differences between tube and other geometries make a comparison between tubing and other data important for verification purposes. However, obtaining crack initiation and growth data from tubing is difficult due to the geometry and the thin wall thickness
43
Brisson, Bruce W. (Bruce William). "Stress corrosion crack detection in alloy 600 in high temperature caustic". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40241.
Testo completo
44
Kotian, Kunal. "Detection of in-plane stress waves with Polyvinylidene Fluoride (PVDF) sensors". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1357254821.
Testo completo
45
Eder, Véronique. "Detection de la restenose apres angioplastie coronaire par l'echographie de stress". Clermont-Ferrand 1, 1994. http://www.theses.fr/1994CLF1MS02.
Testo completo
46
Butrym, Brad A. "Crack Detection in Aluminum Structures". Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/32276.
Testo completoAbstract (sommario):
Structural health monitoring (SHM) is the process of using measurements of a structureâ s response to known excitations and trying to determine if damage has occurred to the structure. This also fits the description of non-destructive evaluation (NDE). The main difference is that NDE takes place while the structure is out of service and SHM is intended to take place while the structure is in service. As such, SHM provides the opportunity to provide early warning against structural failure. This thesis intends to advance the state of the art in SHM by examining two approaches to SHM: vibration based and impedance based, and to associate these with the NDE method of stress intensity factors. By examining these methods the goal is to try and answer some of the important questions in SHM process. The first is to experimentally validate a crack model and to see how small of a crack can be detected by vibration methods. The second is to use the concept of stress intensity factor to perform an SHM type of measurement to determine the remaining life of a structure once the impedance method has determined that damage has occurred.
The measurement system considered consists of using several different piezoceramic materials as self-sensing actuators and sensors. The structures are a simple beam and a more complex lug element used in aircraft applications. The approach suggested here is to use the impedance and vibration methods to detect crack initiation and then to use the proposed stress intensity method to measure the stress intensity factor of the structure under consideration.Master of Science
47
Richardson, Hayley. "Acute stress disorder and posttraumatic stress disorder after injury and illness : its presentation and detection in medical settings". Thesis, University of Warwick, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397101.
Testo completo
48
Hooper, Stephanie Elaine. "Separation and Detection of 2,3-Dihydroxybenzoic Acid". Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/10112.
Testo completoAbstract (sommario):
In Parkinson's disease, severe damage to nigrostriatal neurons causes a depletion of the neurotransmitter dopamine (DA). Oxidative stress on the brain is thought to contribute to neuron cell death and to the onset of Parkinson's disease. Reactive oxygen radicals produced during oxidative stress have been implicated as an initiator of neuron destruction. Glutamate, an excitatory neurotransmitter, can initiate OH radical formation when present in excess. Oxidative stress on the brain caused by glutamate overflow may be monitored by trapping the OH radicals with salicylic acid to produce 2,3-dihydroxybenzoic acid (2,3-DHBA). Determination of this product is initially performed using capillary zone electrophoresis (CZE) coupled with UV detection to establish optimum separation conditions. These conditions were applied for rapid, efficient, and sensitive determination of 2,3-DHBA by CZE coupled with electrochemical detection. Quick and sensitive detection of 2,3-DHBA is essential in monitoring OH radical generation and identifying its role in Parkinson's disease.Master of Science
49
Bernstein, Yaniv, e ybernstein@gmail com. "Detection and management of redundancy for information retrieval". RMIT University. Computer Science and Information Technology, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070417.160526.
Testo completoAbstract (sommario):
The growth of the web, authoring software, and electronic publishing has led to the emergence of a new type of document collection that is decentralised, amorphous, dynamic, and anarchic. In such collections, redundancy is a significant issue. Documents can spread and propagate across such collections without any control or moderation. Redundancy can interfere with the information retrieval process, leading to decreased user amenity in accessing information from these collections, and thus must be effectively managed. The precise definition of redundancy varies with the application. We restrict ourselves to documents that are co-derivative: those that share a common heritage, and hence contain passages of common text. We explore document fingerprinting, a well-known technique for the detection of co-derivative document pairs. Our new lossless fingerprinting algorithm improves the effectiveness of a range of document fingerprinting approaches. We empirically show that our algorithm can be highly effective at discovering co-derivative document pairs in large collections. We study the occurrence and management of redundancy in a range of application domains. On the web, we find that document fingerprinting is able to identify widespread redundancy, and that this redundancy has a significant detrimental effect on the quality of search results. Based on user studies, we suggest that redundancy is most appropriately managed as a postprocessing step on the ranked list and explain how and why this should be done. In the genomic area of sequence homology search, we explain why the existing techniques for redundancy discovery are increasingly inefficient, and present a critique of the current approaches to redundancy management. We show how document fingerprinting with a modified version of our algorithm provides significant efficiency improvements, and propose a new approach to redundancy management based on wildcards. We demonstrate that our scheme provides the benefits of existing techniques but does not have their deficiencies. Redundancy in distributed information retrieval systems - where different parts of the collection are searched by autonomous servers - cannot be effectively managed using traditional fingerprinting techniques. We thus propose a new data structure, the grainy hash vector, for redundancy detection and management in this environment. We show in preliminary tests that the grainy hash vector is able to accurately detect a good proportion of redundant document pairs while maintaining low resource usage.
50
Watkins, Oliver John. "Stochastic reachability, conflict detection and air traffic management". Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615088.
Testo completo