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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Za plotem čeká vlk. Mezidruhové soužití na Broumovsku v antropocénu / A wolf is waiting behind the fence. Multispecies coexistence in Broumovsko region in the Anthropocene

Senft, Lukáš January 2020 (has links)
This diploma thesis traces the changing human, animal and technology assemblage after the recent emergence of wolf packs in Broumov region. As the return of wolves coincides with ecological transformations gaining in strength, the central research focus are the possibilities - and impossibilities - of local multispecies coexistence in the conditions of Anthropocene. The research draws upon methods of multispecies ethnography, building on the literature that examines the ontological aspects of multispecies coexistence, including primarily the work of Donna Haraway, Eduardo Kohn, Annemarie Mol, Anna Tsing and Rane Willerslev. The thesis analyzes several modes of situated multispecies coexistence which have been reconfigured or made possible by the return of wolves: administrative and sensual practice of shepherds, methods of mimetic empathy of wolf trackers, emergence of new actors interfering with local events (satellites, subsidy programmes, drought) and the translation of processes on pastures into politically engaged activities of local farmers. The thesis develops the employed concepts in such a way that they enable analyzing the situation in Broumov region as situated making of more-than-human sociality. Key words: multispecies ethnography, wolfs, pastoralism, trackers, more-than-human sociality
32

Mobile period tracker apps and personalisation : Creating a personalised design that meets the diverse needs of people who menstruate

Shauchuk, Aliaksandra January 2023 (has links)
The popularity of mobile period tracker apps, designed to help women track their periods and fertility, has skyrocketed over the past decade. The target audience is people who menstruate, most often women. There are numerous articles on personalisation in mobile apps, but personalisation in mobile period tracker apps has been little studied. Therefore, in this thesis, I analyse the ways of collecting information about users and personalising the user's account in the period tracker apps, as well as whether this personalisation meets the needs of female users. My research question is: How could the personalisation of mobile period tracker apps be improved through design to meet real users' needs? The study builds on the user experience (UX) design process and consists of the following phases: UX research, design, and user testing. In addition, it includes an ideation part. I used post-structural feminist theory from the perspective of Judith Butler's work as a framework. I conducted seven semi-structured interviews with female users who actively use period tracker apps. I studied three chosen period tracker apps using the walkthrough method and conducted a co-design workshop using the themes identified through the thematic analysis of the interviews. The research output is a design solution tested on five participants of the study and then iterated. Through my work, I contribute to studies of reproductive technologies and the field of feminist human-computer interaction (HCI) through suggestions on personalisation.
33

Analyzing and developing precise pointing analysis tool to reduce image distortion in Earth Observation satellites

Vohra, Vidhan January 2023 (has links)
With growing space market and entry of more private companies into the industry, there arecompanies and stakeholders who would like to have a high order of accuracy mission outputrequirements. These requirements vary from mission to mission. This simply means that if acompany wants an Earth observation mission, the main requirement to be fulfilled would be tohave the highest resolution of image possible. In order to achieve this, the satellite carrying the camera payload would be required to bepointed in the right direction with utmost accuracy. For a satellite to be pointed in the rightdirection, the noise generated by the sensors and actuators on-board, which determines theattitude of the satellite and helps in changing it, should be minimized. The aim of this thesisis to design a method which could help in determining the right components to be procuredso that the pointing requirements of the satellite are fulfilled. This objective is achieved bydesigning algorithms in python and MATLAB. The values generated by these algorithms, ultimately describe the type of sensor or actuator to be procured. Finally, the noise generated bysuch individual components act as pointing error source and then PEET is used to translatethese error sources to platform error, to generate a pointing budget and ensure that all pointingrequirements are satisfied.
34

PrivacyLamp

Knudsen, Tore January 2017 (has links)
This thesis project presents a research through design process, that has aimed to investigate and challenge internet users’ perception and awareness around the theme of online privacy and third-party trackers. This has been done by designing a critical design artifact called PrivacyLamp which takes form as a classic lamp, that through a secondary (dis)functionality is designed to work as an mediation of potential third-par- ty-trackers activity on the user’s local network. PrivacyLamp has been developed through an iterative design process, guid- ed by relevant literature and works within the eld of critical design, physical data visualization, and design for re ection, which all have worked as a foundation for the design of such an artefact. The prototype has been evaluated together with six participants, who all adopted the prototype into their domestic settings to experience it as a part of their everyday life for a few days. The aim of this qualitative study has been to investigate how a defamiliarized domestic object can work as an ambient display to question the invisible ow of connec- tivity and its complication within online privacy, as well as the narratives and experiences users develops in relation to this.
35

Activité physique dans le cancer du sein métastatique : faisabilité et résultats d’une intervention (études ABLE et MUST) et lien avec la survie (étude StoRM) / Physical Activity in Metastatic Breast Cancer : Feasibility and results of an intervention (ABLE and MUST studies) and association with Survival (StoRM study)

Delrieu, Lidia 19 November 2018 (has links)
Environ 5% des patientes sont diagnostiquées chaque année avec un cancer du sein d’emblée métastatique et 20 à 30% des cancers du sein localisés évoluent vers un stade secondairement métastatique. Les bénéfices de l’activité physique pendant les traitements chez les patientes avec un cancer du sein localisé ont largement été démontrés mais la littérature est limitée dans le cancer du sein métastatique. Ce travail de thèse a permis d’évaluer les effets potentiels de l’activité physique chez des patientes atteintes d’un cancer du sein métastatique à travers trois études.L’étude observationnelle StoRM a montré une association du niveau d’activité physique recueilli par questionnaire à une meilleure survie des patientes HER2. L’étude interventionnelle ABLE a mis en évidence la faisabilité d’une intervention en activité physique avec une montre connectée dans cette population avec un excellent taux d’adhérence (96%), l’intérêt et la volonté des patientes pour les programmes d’activité physique ainsi qu’une amélioration fonctionnelle. L’intervention a contribué au un maintien de la qualité de vie, de la fatigue et du niveau d’activité physique malgré les traitements et l’avancée de la maladie. De potentiels biomarqueurs prédictifs d’une progression tumorale ont été identiés. L’étude MUST a montré que l’antioxydant SOD et de la force isométrique d’extension du quadriceps semblent prévenir la sarcopénie et une association entre le statut sarcopénie et le risque de toxicités a été confirmé. Ce travail de thèse représente une première étape dans l’analyse des effets de l’activité physique auprès de patientes atteintes d’un cancer du sein métastatique. L’activité physique semble être bénéfique dans cette population, mais ces résultats nécessitent d’être confirmés dans une étude à plus grande échelle. Ces résultats préliminaires soulignent l’importance de proposer des interventions adaptées en activité physique aux patientes atteintes d’un cancer du sein métastatique dès le diagnostic pour poursuivre un mode de vie actif le plus longtemps possible / Approximately 5% of patients are diagnosed with metastatic breast cancer each year and 20 to 30% of localized breast cancers become secondarily metastatic. Benefits of physical activity during treatment in patients with localized breast cancer have been widely demonstrated, but the literature is limited in metastatic breast cancer. This thesis work assessed the potential effects of physical activity in patients with metastatic breast cancer through three studies.The StoRM observational study showed an association between the level of physical activity collected by questionnaire with an improvement of survival for HER2 patients. The ABLE intervention study highlighted the feasibility of a physical activity intervention with an activity tracker in this population with an excellent adherence rate (96%), patients' interest and willingness to participate in physical activity programs and functional improvements. The intervention contributed to maintaining quality of life, fatigue and physical activity levels despite treatment and disease progression. Potential biomarkers predictive of tumor progression have been identified. The MUST study showed that the antioxidant SOD and quadriceps isometric extension force appear to prevent sarcopenia and an association between sarcopenia status and toxicity risk was confirmed. This thesis work represents a first step in analyzing the effects of physical activity on patients with metastatic breast cancer. Physical activity appears to be beneficial in this population, but these results need to be confirmed in a larger scale study. These preliminary results highlight the importance of providing appropriate physical activity interventions for patients with metastatic breast cancer at the time of diagnosis in order to maintain an active lifestyle as long as possible
36

Energy-Efficient Private Forecasting on Health Data using SNNs / Energieffektiv privat prognos om hälsodata med hjälp av SNNs

Di Matteo, Davide January 2022 (has links)
Health monitoring devices, such as Fitbit, are gaining popularity both as wellness tools and as a source of information for healthcare decisions. Predicting such wellness goals accurately is critical for the users to make informed lifestyle choices. The core objective of this thesis is to design and implement such a system that takes energy consumption and privacy into account. This research is modelled as a time-series forecasting problem that makes use of Spiking Neural Networks (SNNs) due to their proven energy-saving capabilities. Thanks to their design that closely mimics natural neural networks (such as the brain), SNNs have the potential to significantly outperform classic Artificial Neural Networks in terms of energy consumption and robustness. In order to prove our hypotheses, a previous research by Sonia et al. [1] in the same domain and with the same dataset is used as our starting point, where a private forecasting system using Long short-term memory (LSTM) is designed and implemented. Their study also implements and evaluates a clustering federated learning approach, which fits well the highly distributed data. The results obtained in their research act as a baseline to compare our results in terms of accuracy, training time, model size and estimated energy consumed. Our experiments show that Spiking Neural Networks trades off accuracy (2.19x, 1.19x, 4.13x, 1.16x greater Root Mean Square Error (RMSE) for macronutrients, calories burned, resting heart rate, and active minutes respectively), to grant a smaller model (19% less parameters an 77% lighter in memory) and a 43% faster training. Our model is estimated to consume 3.36μJ per inference, which is much lighter than traditional Artificial Neural Networks (ANNs) [2]. The data recorded by health monitoring devices is vastly distributed in the real-world. Moreover, with such sensitive recorded information, there are many possible implications to consider. For these reasons, we apply the clustering federated learning implementation [1] to our use-case. However, it can be challenging to adopt such techniques since it can be difficult to learn from data sequences that are non-regular. We use a two-step streaming clustering approach to classify customers based on their eating and exercise habits. It has been shown that training different models for each group of users is useful, particularly in terms of training time; however this is strongly dependent on the cluster size. Our experiments conclude that there is a decrease in error and training time if the clusters contain enough data to train the models. Finally, this study addresses the issue of data privacy by using state of-the-art differential privacy. We apply e-differential privacy to both our baseline model (trained on the whole dataset) and our federated learning based approach. With a differential privacy of ∈= 0.1 our experiments report an increase in the measured average error (RMSE) of only 25%. Specifically, +23.13%, 25.71%, +29.87%, 21.57% for macronutrients (grams), calories burned (kCal), resting heart rate (beats per minute (bpm), and minutes (minutes) respectively. / Hälsoövervakningsenheter, som Fitbit, blir allt populärare både som friskvårdsverktyg och som informationskälla för vårdbeslut. Att förutsäga sådana välbefinnandemål korrekt är avgörande för att användarna ska kunna göra välgrundade livsstilsval. Kärnmålet med denna avhandling är att designa och implementera ett sådant system som tar hänsyn till energiförbrukning och integritet. Denna forskning är modellerad som ett tidsserieprognosproblem som använder sig av SNNs på grund av deras bevisade energibesparingsförmåga. Tack vare deras design som nära efterliknar naturliga neurala nätverk (som hjärnan) har SNNs potentialen att avsevärt överträffa klassiska artificiella neurala nätverk när det gäller energiförbrukning och robusthet. För att bevisa våra hypoteser har en tidigare forskning av Sonia et al. [1] i samma domän och med samma dataset används som utgångspunkt, där ett privat prognossystem som använder LSTM designas och implementeras. Deras studie implementerar och utvärderar också en klustringsstrategi för federerad inlärning, som passar väl in på den mycket distribuerade data. Resultaten som erhållits i deras forskning fungerar som en baslinje för att jämföra våra resultat vad gäller noggrannhet, träningstid, modellstorlek och uppskattad energiförbrukning. Våra experiment visar att Spiking Neural Networks byter ut precision (2,19x, 1,19x, 4,13x, 1,16x större RMSE för makronäringsämnen, förbrända kalorier, vilopuls respektive aktiva minuter), för att ge en mindre modell ( 19% mindre parametrar, 77% lättare i minnet) och 43% snabbare träning. Vår modell beräknas förbruka 3, 36μJ, vilket är mycket lättare än traditionella ANNs [2]. Data som registreras av hälsoövervakningsenheter är enormt spridda i den verkliga världen. Dessutom, med sådan känslig registrerad information finns det många möjliga konsekvenser att överväga. Av dessa skäl tillämpar vi klustringsimplementeringen för federerad inlärning [1] på vårt användningsfall. Det kan dock vara utmanande att använda sådana tekniker eftersom det kan vara svårt att lära sig av datasekvenser som är oregelbundna. Vi använder en tvåstegs streaming-klustringsmetod för att klassificera kunder baserat på deras mat- och träningsvanor. Det har visat sig att det är användbart att träna olika modeller för varje grupp av användare, särskilt när det gäller utbildningstid; detta är dock starkt beroende av klustrets storlek. Våra experiment drar slutsatsen att det finns en minskning av fel och träningstid om klustren innehåller tillräckligt med data för att träna modellerna. Slutligen tar denna studie upp frågan om datasekretess genom att använda den senaste differentiell integritet. Vi tillämpar e-differentiell integritet på både vår baslinjemodell (utbildad på hela datasetet) och vår federerade inlärningsbaserade metod. Med en differentiell integritet på ∈= 0.1 rapporterar våra experiment en ökning av det uppmätta medelfelet (RMSE) på endast 25%. Specifikt +23,13%, 25,71%, +29,87%, 21,57% för makronäringsämnen (gram), förbrända kalorier (kCal), vilopuls (bpm och minuter (minuter).
37

Development Of Gyroless Attitude And Angular Rate Estimation For Satellites

Vivek Chandran, K P 07 1900 (has links)
Studies aimed at the development of indigenous low cost star tracker and gyroless attitude and angular rate estimation is presented in the thesis. This study is required for the realization of low cost micro satellites. A target specification of determining the attitude with accuracy (3σ) of 0.05 degrees and attitude rate with accuracy (3σ) in the range of 50rad/sec at a rate of 10 samples/second in all the axes is set as a goal for the study. Different sensor arrays available in the market are evaluated on the basis of their noise characteristics, resolution of the analog-to-digital converter (ADC) present and ability to work in low light conditions, for possible use in the hardware realization of star tracker. STAR1000 APS CMOS array, manufactured by Cypress Semiconductors, qualified these performance criteria, is used for the simulation study. An algorithm is presented for scanning the sensor array, detection of star image and retrieving the information concerning the photoelectron counts corresponding to a star image. The exact designation of the center of the star image becomes crucial as it has direct implications on the accuracy of the estimated attitude. Various algorithms concerning the centroid estimation of a defocused star image on the sensor array to subpixel accuracy are studied and Gaussian Weighed Center of Gravity algorithm is adapted with some modifications and an accuracy of 0.039 pixels is obtained in both horizontal and vertical direction of the array. A one-to-one relationship is established between the stars obtained in the field-of-view (FOV) of the star tracker with the stars present in the star catalog resident in the star tracker through star identification algorithm. A star identification algorithm which relies on the interstar angles and brightness of the stars is developed in this thesis. The interstar angles of the stars visible in the FOV of the star sensor is recorded, compared with the inter-star angles made by the stars selected in the catalog, based on initial brightness match with stars formed on image plane. After identification at the initial epoch, consequent instants can drive information from the previous matches so as to decrease the computational complexity and storage requirement for the subsequent instants. The memory constraints and computational overhead on the processor and the dynamic range of the image detector used in the star tracker are the limiting factors. The stars thus identified with the stars in the catalog are used for the estimation of attitude. A point solution to the attitude estimation problem is computed using a least square based algorithm called ESOQ-2. The algorithm for centroiding of star images and ESOQ-2 for finding the point solution satellite attitude is coded and tested on Da Vinci based emulator. This exercise shows that it is possible to implement above algorithm for real time operations. Estimation of attitude at a given epoch using algorithms like ESOQ-2 does not minimize the noise and error covariance as the attitude estimated at each instant of time depends only on the measurement taken at that particular instant. So a Kalman Filter (KF) based estimation using Integrated Rate Parameter (IRP) formulation called SIAVE algorithm, is adapted, with some modifications, for the estimation of incremental angle and attitude rates from vector observations of stars. From the point solution of attitude estimation problem of the satellite, the incremental angle and angular rate at successive time steps are predicted using a linear KF and refined with the measurements from the stand alone star tracker, taken at discrete time steps, using the SIAVE algorithm. The sensor noise is modeled from the characteristics of STAR1000 sensor array used in the algorithm in order to make the simulations more realistic in nature. The optimality of Kalman filter is based on the assumption that the state and measurement noises are white gaussian random processes and the state dynamics of the plant is completely known. However, for most real systems, modeling uncertainties are present. So a robust state estimator based on H∞ norm minimization is devised. The H∞ filter, based on game theory approach is used to minimize the worst case variance of noise signals with the only assumption on the noise signals that they are energy bounded. The aim is to find the feasibility of using H∞ filter for the estimation of incremental angle and attitude rate of the satellite. The studies shows that H∞ filter with proper tuning can serve as potential estimation scheme for the attitude and angular rate estimation of the satellite. It is found that both Kalman filter and H∞ are able to meet the specified accuracy desired from low cost accurate star sensor.
38

Εξομοίωση φωτοβολταϊκού συστήματος διασυνδεδεμένου στο δίκτυο / Simulation of a grid connected photovoltaic system

Ματσώκης, Αριστείδης 11 May 2007 (has links)
Σκοπός της συγκεκριμένης διπλωματικής εργασίας είναι η εξομοίωση ενός φωτοβολταϊκού συστήματος διασυνδεδεμένου στο τριφασικό δίκτυο με σκοπό τη μελέτη της λειτουργίας του και του καλύτερου σχεδιασμού του. Το σύστημα περιλαμβάνει τη φωτοβολταϊκή γεννήτρια, ένα φίλτρο διασύνδεσης της γεννήτριας με τον αντιστροφέα και ένα απλοποιημένο μοντέλο του τριφασικού συστήματος. Για την εξομοίωση του κυκλώματος το οποίο είναι χρονικά μεταβαλλόμενο λόγω της διακοπτικής λειτουργίας του μετατροπέα αναπτύσσεται μια συστηματική και αποτελεσματική μέθοδος για την ανάλυση κυκλωμάτων που περιέχουν e-R-L, C κλάδους και ιδανικούς διακόπτες. Χρησιμοποιώντας την τοπολογία του κυκλώματος και κατάλληλες μήτρες μετασχηματισμού οι εξισώσεις που περιγράφουν το αγώγιμο και μη αγώγιμο τμήμα του κυκλώματος προκύπτουν αυτόματα. Οι χρησιμοποιούμενες μήτρες μετασχηματισμού προκύπτουν με απλό και συστηματικό τρόπο από τις θεμελιώδης μήτρες του κυκλώματος. Σε κάθε βήμα προκύπτουν τα ρεύματα όλων των κλάδων του κυκλώματος από την επίλυση του αγώγιμου τμήματος αυτού και οι τάσεις των βαλβίδων που δεν άγουν από την επίλυση του μη αγώγιμου τμήματός του. Η μέθοδος είναι γενική και μπορεί να εφαρμοστεί για την μελέτη τυχόντων σφαλμάτων σε οποιοδήποτε τμήμα του κυκλώματος. Παρουσιάζονται τα αποτελέσματα της εξομοίωσης για λειτουργία του μετατροπέα ως ανορθωτή, ως αντιστροφέα, ως αντιστροφέα με φωτοβολταϊκή γεννήτρια και ως αντιστροφέα με φωτοβολταϊκή γεννήτρια και με ανιχνευτή σημείου μέγιστης ισχύος. Το χρησιμοποιηθέν μοντέλο θα μπορούσε να βελτιωθεί αν στην θέση του τριφασικού συστήματος χρησιμοποιηθεί ακριβέστερη αναπαράσταση του τριφασικού δικτύου στην οποία να περιλαμβάνεται και ο τριφασικός μετασχηματιστής ισχύος που διασυνδέει το φωτοβολταϊκό σύστημα με το AC δίκτυο. / The objective of this “Diploma Thesis” is the simulation of a grid connected photovoltaic (PV) system and the study of its operation. The system consists of a PV generator, a DC filter and a simplified model of the three-phase system. The method which was used for the simulation of the circuit (which is a varying topology circuit due to the switching operation of the converter) is a systematic, efficient and conceptually simple method for the analysis of circuits consisting of linear e, R, L, C elements and ideal switches. On the basis of well known network topological concepts a suitable transformation tensor is constructed at every step. This tensor constitutes a flexible and powerful tool to assemble automatically the necessary on-switch current and off-switch voltage equations required for any conduction pattern. The method is general and can be applied for the study of any random faults in any part of the circuit. Results of the simulation for operation of the converter as rectifier, as inverter with battery, as inverter with PV generator and as inverter with PV generator and with MPPT are presented. The used model could be improved if the three-phase system is more precisely represented by a power three-phase transformer which connects the PV system with the AC network.
39

Fysisk aktivitetsnivå, smärtintensitet och funktionsnedsättning hos personer med ländryggssmärta : - En enkätstudie / Level of physical activity, pain intensity and disability among people with lower back pain : - A survey study

Gunnesson, Linnea, Zetterlund, Anna January 2018 (has links)
Bakgrund Ländryggssmärta är mycket vanligt förekommande i västvärlden. Det innebär stort lidande för individen och stora kostnader för samhället. Idag behandlas ryggsmärta med information om att vara aktiv och vid behov rådgivning om smärtstillande läkemedel. Mer kunskap behövs gällande fysisk träning som prevention och behandling av akut- och subakut ländryggssmärta. Syfte Syftet med studien var att, för patienter med akut- och subakut ländryggsmärta, beskriva den fysiska aktivitetsnivån samt eventuella skillnader i smärtintensitet och funktionsnedsättning mellan grupper med olika aktivitetsnivåer. Syftet var även att undersöka samband mellan aktivitetsnivå och smärtintensitet respektive aktivitetsnivå och funktionsnedsättning. Metod Studien var en enkätstudie med tvärsnittsdesign. Deltagarna var 15 patienter, 9 kvinnor och 6 män, medelålder 49,2 år, som sökt vård för akuta eller subakuta ländryggsbesvär till 4 olika primärvårdsenheter. Fysisk aktivitetsnivå skattades via Socialstyrelsens indikatorfrågor för fysisk aktivitet, smärtan med numerisk skattningsskala 0-10 (NRS) och Roland Morris Disability Questionnaire (RMDQ) besvarades. Data sammanställdes med deskriptiv statistik, skillnader testades med Mann-Whitney U-test och samband analyserades med Spearmans korrelationskoefficient. Resultat Åtta av 15 deltagare uppnådde Världshälsoorganisationens (WHO) rekommendationer för fysisk aktivitet (> 150 minuter i veckan). De som ägnade sig åt fysisk träning minst 90 minuter per vecka hade medianvärde NRS 5,5 och RMDQ 8, för de som tränade mindre var motsvarande värden NRS 7,5 (p=0,153) och RMDQ 11,5 (p=0,175). Ett svagt negativt samband identifierades mellan NRS (r=-0,316,) och nivå av fysisk aktivitet medans sådant samband mellan RMDQ och fysisk aktivitetsnivå var negligerbart (r=-0,158). Slutsats Det var ingen statistiskt signifikant skillnad mellan grupperna som tränade minst 90 minuter per vecka och de som tränade mindre gällande varken smärtintensitet eller funktionsnedsättning. Ett svagt negativt men ej statistiskt signifikant samband kan ses mellan fysisk aktivitetsnivå och smärtintensitet. / Background Lower back pain is very common in the western world. It results in a great suffering for the person and large economic costs for the society. Today lower back pain is treated with information to stay active and medication for pain relief. There is a lack of knowledge with regards to what effect physical training has as prevention and treatment for acute and subacute lower back pain. Aim The aim of this study was to, among patients with acute and subacute non-specific lower back pain, describe their level of physical activity and evaluate differences between groups with different levels of activity. The aim was also to explore the association between pain intensity, disability and level of physical activity. Method The study was conducted as a survey. The participants was 15 patients, 6 men and 9 women with the mean age of 49,2 years old, who had sought care for acute and subacute lower back pain in 6 different primary care clinics. The level of physical activity were estimated using the indicator questions for physical activity by Socialstyrelsen, the pain intensity was measured with the Numeric Rating Scale and the Roland Morris Disability Questionnaire was answered. Data was analyzed with descriptive statistics, differences were tested with Mann-Whitney U-test and correlations analyzed with Spearman correlations coefficient. Results Eight out of 15 participants reached the WHO recommendations of physical activity (> 150 min/week). Those who participated in physical training minimum 90 mins/week had a median value of NRS 5,5 and RMDQ 8. For those who trained less the median values were for NRS 7,5 (p=0,153) and RMDQ 11,5 (p=0,175). A week correlation between NRS (r=-0,136) and level of physical activity was noted while such correlation between RMDQ was negligible (r=-0,158). Conclusion There were no statically significant difference between the groups who trained at least 90 minutes per week and those who trained less neither in regards to pain intensity or disability. A weak but not statistically significant correlation was observed between physical activity and pain intensity.
40

Supporting Real-Time, Automated Evaluation of Difficulty in Manual Assembly

Santhi, B January 2017 (has links) (PDF)
Product designers address the costs of assembly during the design process. Design process can be more efficient if assembly issues could be addressed early in its design process. Doing this requires the ability to assess assemblability among others. Assemblability refers to the ease of assembling the final product from its parts. Assemblability evaluation is applied by product designers for quantitatively estimating the degree of difficulty of the assembly. This helps in identifying areas of improvement, so as to reduce process time and production costs. This work focuses on assessing assemblability in a manual assembly and its importance in the earlier phases of design. Literature contains various methods for assessing assemblability (e.g. Boothroyd-Dewhurst method, the DFA house, Sturges DFA calculator and Sony DFA method). These methods are typically rule-based and their use requires insight and knowledge on the part of the designer. Further, the designer has to interpret and apply them differently in each specific and unique case. Literature also contains methods for ergonomic assessment of manual work and its link with assemblability. Both observation based ergonomic assessment such as RULA, REBA, VIDAR, LUBA and OWAS and instrumentation based ergonomic assessment using electro-goniometer and accelerometer are the techniques reviewed in this thesis for their suitability in assembly assessment. The most recent trend in the area is automation of the evaluation process. This thesis proposes an approach to automated assessment of assemblability using electromagnetic trackers. In spite of advances in industrial automation, manual assembly tasks continue to be an important feature of many industrial operations. The method proposed in the thesis is for the assessment of assemblability of manual assembly that combines both time and postural analysis. The tool used for the static analysis is called Rapid Upper Limb Assessment (RULA); for dynamic analysis a new method of time analysis is proposed that is based on the ratio of time spent in fine and gross motions carried out in an assembly process. The difficulty of assembly of a series of manual assembly tasks are carried out in a laboratory setting. Then by correlating this assessment with the feedback on the difficulty of these assembly task obtained from the subjects who carried out these tasks. The remaining work carried out as a part of this thesis is focussed on automating the process of carrying out the above assessment in an automated manner. Suitability of electromagnetic trackers as a means for automated capture of data necessary for executing the proposed assessment method is studied. Electromagnetic trackers have been used to capture postural data for various limbs of the assembly operators. Data from the limbs are then analysed to identify, to which limb movement signifies which sources of difficulty (i.e. reach, visibility, etc.) in assembly; for example reach difficulty is indicated by torso movement. Finally, the thesis proposes as a part of the future work in possible improvement of the assessment method. Also, its application using a virtual reality (VR) platform assesses in ascertaining ease or difficulties in assembly and many.

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