<p>Inom avancerad produktionsindustri använder man sig fortfarande i stor utsträckning av manuell provning för att säkra kvaliteten på de tillverkade produkterna. Detta innebär, förutom att man ofta bara tar stickprov, även en viss fördröjning innan upptäckt av eventuella kvalitetsbrister. Dessutom finns en osäkerhetsfaktor härrörande från den mänskliga faktorn eftersom människans kognitiva förmågor påverkas av dagsform, stressupplevelse, personliga erfarenheter med mera.</p><p><strong></strong></p><p>Examensarbetet har utförts vid Linköpings universitet inom ramen för en magisterutbildning i Ergonomi och MTO (Människa Teknik Organisation). Syftet är att undersöka potentiella vinster vid minskning av den mänskliga faktorn vid övergång från manuell till automatiserad OFP (oförstörande provning). Arbetet består av en litteraturstudie, enkäter till operatörer samt intervjuer med beslutsfattare.</p><p><strong></strong></p><p>Vid detektering, lokalisering, särskiljning, jämförelse och kategorisering spelar perceptionen en stor roll. Den mänskliga faktorn är ett av de huvudelement som påverkar kvaliteten vid oförstörande provning. Operatören är således den största källan till tillförlitlighetsvariation (Dickens & Bray, 1994). OFP - utrustningen visar bara rätt information om den hanteras korrekt. Dessutom behöver informationen tolkas och sammanställas för att en bedömning ska kunna göras.</p><p><strong></strong></p><p>Åtskilliga studier har visat låg detekteringsgrad för flera olika OFP - metoder (runt 50 %) och flera storskaliga forskningsprogram har visat att automatiserad provning är överlägsen den manuella (PISC, NORDEST, NIL, ICON, TIP). Flera studier har visat högre detekteringsgrad (84-90 % jämfört med 50-52 %) och lägre kostnader (minskning med ca 40 %) vid automatisering av provningen. (Wassink & Dijkstra, 2007, Verkooijen, 1998).</p><p><strong></strong></p><p>Knappt 70 operatörer i tillverkningsindustrin har deltagit i denna studie genom att fylla i en enkät om sin arbetssituation. Operatörerna tror själva att stress, trötthet, monotonitet och distraktion i nämnd ordning har negativ påverkan på detekteringsgraden. 97 % av dem tror att automatisering av moment skulle öka andelen funna fel.</p><p> </p><p>Fem beslutsfattare inom olika tillverkningsindustrier har deltagit i studien genom intervjuer kring varför man valt att automatisera. Beslutsfattarna nämner ekonomi och kvalitet som främsta orsaker till att man valt att automatisera provningen. Flera anser att felfrekvensen vid manuell provning var för hög för att man skulle kunna leva upp till kvalitetskraven. Även ergonomi har spelat in eftersom man sparat mycket pengar på minskad sjukfrånvaro. Provningen anses bli mer heltäckande och dokumentationen bättre. Flera uppskattar tids- och kostnadsbesparingar till minst 60 %. Samtliga är nöjda med övergången och kommer att fortsätta automatisera flera moment.</p> / <p>In advanced production industry manual testing is still a common method for ensuring quality of manufactured products. This means apart from the fact that it is often a spot check also a certain delay before possible quality problems are discovered. Additionally there is an uncertainty due to the human factor since the human cognitive behavior is affected by day form, experienced stress, and personal practice etcetera.</p><p> </p><p>This thesis has been carried out at the University of Linköping as a part of a Master in ergonomics degree. The aim is to investigate potential benefits due to less influence of the human factor, when shifting from manual to automated NDT (non destructive testing). The work includes a literature review, operator questionnaires and interviews with decision makers.</p><p> </p><p>At detection, localization, separation, comparison and categorization human perception is of great importance. The human factor is one of the main elements affecting the quality of nondestructive testing. The operator therefore is the main source of reliability variations. The NDE equipment only shows the right information if it is handled the right way. In addition the information needs to be interpreted and put together for an assessment to be made.</p><p> </p><p>Several studies have shown low detection rate for various NDT methods (around 50 %) and a number of large-scale research programs have shown that automated testing is superior to manual (PISC, NORDEST, NIL, ICON, TIP). Various studies have shown higher detection rate (84-90 % compared to 50-52 %) and lower costs (reduction of approx. 40 %) by automation of the testing (Wassink & Dijkstra, 2007, Verkooijen, 1998).</p><p> </p><p>Almost 70 operators in the manufacturing industry took part in this study by answering a questionnaire about their working situation. The operators themselves believe that stress, drowsiness, monotony and distraction, in the order mentioned, have negative effect on the detection rate. 97 % of them think that by automating some elements, the detection rate would increase.</p><p> </p><p>Five decisions makers in the manufacturing industry took part in the study thru interviews concerning the reason for automating the testing. The decisions makers mention economy and quality as main reasons for choosing changeover to automation. Several think that the error frequency by manual testing is too high to be able to live up to the quality demands. Also ergonomics have played a big role since they have saved a lot of money due to less reporting sick. The testing is believed to be more comprehensive and the documentation better. Several estimate time and cost savings to be at least 60 %. All are satisfied with the changeover and want to automate more elements of the production.</p>

Bakgrund Det finns ännu inga etablerade officiella gränsvärden för övervikt och fetma som är baserade på proportionen fettmassa (FM%) utan de gränsvärden som finns är utgår body mass index (BMI) eller midjemått. Syfte Att utveckla modeller för att prediktera FM, procentuellt och i kg, utifrån antropometriska mått hos unga och medelålders (20-49 år) svenska män. Vidare syftar uppsatsen till att undersöka vilka värden för FM% som motsvarar 25 kg/m2 och 30 kg/m2 i BMI och samt för 94 cm och 102 cm i midjemått. Metod Männen har rekryterats med hjälp av en mödravårdscentral, kvinnohälsan, i Linköping i samband med ett projekt om utveckling av barnfetma. Totalt 136 män undersöktes med Bod Pod, en maskin som mäter kroppssammansättning med hög validitet. Vidare mättes antropometriska mått såsom vikt, längd och midjemått vid mättillfället. Resultat Regressionsmodellerna med midjemått och BMI (r=0,94) samt midjemått (r=0,94) var de som var signifikant högst korrelerade till FM (kg). De regressionsmodellerna som förklarade mest av variansen i FM% var de med 1) M/L (midja/längd), midjemått och BMI 2) M/L och 3) midjemått som oberoende variabler (r=0,86-0,88). Ett BMI på 25 kg/m2 och 30 kg/m2 motsvaras av 23, respektive 32 FM%. Motsvarande värden för midjemått 94 och 102 cm var 25, respektive 31 FM%. Slutsats Midjemått och M/L (midjemått/längd) är bäst för att prediktera mängden fettmassa (FM), både i procent och kg. BMI 25 kg/m2 motsvarar 23±1 i FM% och BMI 30 kg/m2 korresponderas av 32±2 i FM%. / Introduction Currently, no official cut-offs regarding overweight and obesity based on proportion fat mass (FM%) are available. Existing cut-offs are instead derived from body mass index (BMI) and waist circumference. Aim To develop equations to predict FM, in percent and kg, from anthropometric measures in young and middle aged (20-49 years of age) Swedish men. Also, this paper aims to investigate which values for FM% that corresponds to firstly 25 kg/m2 and 30 kg/m2 in BMI and secondly to 94 cm and 102 cm in waist circumference. Methods The men in the study were recruited in collaboration with a maternity clinic, kvinnohälsan, in Linköping. In total, 136 men were measured by the means of Bod Pod, a device that measures body composition in a valid manner. Anthropometric measures such as weight, height and waist circumference were measured. Results The regression models with waist circumference and BMI (r=0,94) and waist circumference (r=0,94) were significantly strongest related to FM (kg). The regression models who explained most of the variability in FM% were the ones with 1) W/H (waist circumference/height), waist circumference and BMI 2) W/H and 3) waist circumference as independent variables. A BMI of 25 kg/m2 and 30 kg/m2 corresponds to a FM% of 23 and 32, respectively. Corresponding values for waist circumference (94 and 102 cm) were 25 FM% and 31 FM%, respectively. Conclusion Waist circumference and W/H were the best variables to predict fat mass, both in percent and kg. BMI 25 kg/m2 corresponds to a FM% of 23±1 while BMI 30 kg/m2 is equivalent to 32±2 in FM%.

Nous nous intéressons dans ce mémoire à des méthodes de parallélisation par découplage du système dynamique. Plusieurs applications numériques de nos jours conduisent à des systèmes dynamiques de grande taille et nécessitent des méthodes de parallélisation en conséquence pour pouvoir être résolues sur les machines de calcul à plusieurs processeurs. Notre but est de trouver une méthode numérique à la fois consistante et stable pour réduire le temps de la résolution numérique. La première approche consiste à découpler le système dynamique en sous-systèmes contenant des sous-ensembles de variables indépendants et à remplacer les termes de couplage par l'extrapolation polynomiale. Une telle méthode a été introduite sous le nom de schéma C (p, q, j), nous améliorons ce schéma en introduisant la possibilité à utiliser des pas de temps adaptatifs. Cependant, notre étude montre que cette méthode de découplage ne peut satisfaire les propriétés numériques que sous des conditions très strictes et ne peut donc pas s'appliquer aux problèmes raides présentant des couplages forts entre les sous-systèmes. Afin de pouvoir répondre à cette problématique de découplage des systèmes fortement couplés, on introduit le deuxième axe de recherche, dont l'outil principal est la réduction d'ordre du modèle. L'idée est de remplacer le couplage entre les sous-ensembles de variables du système par leurs représentations sous forme réduite. Ces sous-systèmes peuvent être distribués sur une architecture de calcul parallèle. Notre analyse du schéma de découplage résultant nous conduit à définir un critère mathématique pour la mise à jour des bases réduites entre les sous-systèmes. La méthode de réduction d'ordre du modèle utilisée est fondée sur la décomposition orthogonale aux valeurs propres (POD). Cependant, ne disposant pas à priori des données requises pour la construction de la base réduite, nous proposons alors un algorithme de construction incrémentale de la base réduite permettant de représenter le maximum des dynamiques des solutions présentes dans l'intervalle de simulation. Nous avons appliqué la méthode proposée sur les différents systèmes dynamiques tels que l'exemple provenant d'une EDP et celui provenant de l'équation de Navier Stokes. La méthode proposée montre l'avantage de l'utilisation de l'algorithme de découplage basé sur la réduction d'ordre. Les solutions numériques sont obtenues avec une bonne précision comparées à celle obtenue par une méthode de résolution classique tout en restant très performante selon le nombre de sous-systèmes définis.

This thesis presents a study of the wind load forces and their influence on the response of structures. The study is based on the capacity of the Proper Orthogonal Decomposition method (POD) to identify and extract organized patterns that are hidden or embedded inside a complex field. Technically this complex field is defined as a multi-variate random process, which in wind engineering is represented by unsteady pressure signals recorded on multiple points of the surface of a structure. The POD method thus transforms the multi-variate random pressure field into a sequence of load shapes that are uncorrelated with each other. The effect of each uncorrelated load shape on the structural response is relatively easy to evaluate and the individual contributions can be added linearly afterwards. Additionally, since each uncorrelated load shape is associated with a percentage of the total energy involved in the loading process, it is possible to neglect those load shapes with low energy content. Furthermore, the load shapes obtained with the POD often reveal physical flow structures, like vortex shedding, oscillations of shear layers, etc. This later property can be used in conjunction with classical results in fluid mechanics to theorize about the physical nature of different flow mechanics and their interactions. The POD method is well suited to be used in conjunction with the classical modal analysis, not only to calculate the structural response for a given pressure field but to observe the details of the wind-structure interaction. A detailed and complete application is presented here but the methodology is very general since it can be applied to any recorded pressure field and for any type of structure.

Flow control of transitional shear flows is investigated by means of numerical simulations. The attenuation of three-dimensional wavepackets of Tollmien-Schlichting (TS) and streaks in the boundary layer is obtained using active control in combination with localised sensors and actuators distributed near the rigid wall. Due to the dimensions of the discretized Navier-Stokes operator, reduced-order models are identified, preserving the dynamics between the inputs and the outputs of the system. Balanced realizations of the system are computed using balanced truncation and system identification. We demonstrate that the energy growth of the perturbations is substantially and efficiently mitigated, using relatively few sensors and actuators. The robustness of the controller is analysed by varying the number of actuators and sensors, the Reynolds number, the pressure gradient and by investigating the nonlinear, transitional case. We show that delay of the transition from laminar to turbulent flow can be achieved despite the fully linear approach. This configuration can be reproduced in experiments, due to the localisation of sensing and actuation devices. The closed-loop system has been investigated for the corresponding twodimensional case by using full-dimensional optimal controllers computed by solving an iterative optimisation based on the Lagrangian approach. This strategy allows to compare the results achieved using open-loop model reduction with model-free controllers. Finally, a parametric analysis of the actuators/ sensors placement is carried-out to deepen the understanding of the inherent dynamics of the closed-loop. The distinction among two different classes of controllers – feedforward and feedback controllers - is highlighted. A second shear flow, a confined turbulent jet, is investigated using particle image velocimetry (PIV) measurements. Proper orthogonal decomposition (POD) modes and Koopman modes via dynamic mode decomposition (DMD) are computed and analysed for understanding the main features of the flow. The frequencies related to the dominating mechanisms are identified; the most energetic structures show temporal periodicity. / <p>QC 20130207</p>

This thesis presents a study of the wind load forces and their influence on the response of structures. The study is based on the capacity of the Proper Orthogonal Decomposition method (POD) to identify and extract organized patterns that are hidden or embedded inside a complex field. Technically this complex field is defined as a multi-variate random process, which in wind engineering is represented by unsteady pressure signals recorded on multiple points of the surface of a structure. The POD method thus transforms the multi-variate random pressure field into a sequence of load shapes that are uncorrelated with each other. The effect of each uncorrelated load shape on the structural response is relatively easy to evaluate and the individual contributions can be added linearly afterwards. Additionally, since each uncorrelated load shape is associated with a percentage of the total energy involved in the loading process, it is possible to neglect those load shapes with low energy content. Furthermore, the load shapes obtained with the POD often reveal physical flow structures, like vortex shedding, oscillations of shear layers, etc. This later property can be used in conjunction with classical results in fluid mechanics to theorize about the physical nature of different flow mechanics and their interactions. The POD method is well suited to be used in conjunction with the classical modal analysis, not only to calculate the structural response for a given pressure field but to observe the details of the wind-structure interaction. A detailed and complete application is presented here but the methodology is very general since it can be applied to any recorded pressure field and for any type of structure.

Inom avancerad produktionsindustri använder man sig fortfarande i stor utsträckning av manuell provning för att säkra kvaliteten på de tillverkade produkterna. Detta innebär, förutom att man ofta bara tar stickprov, även en viss fördröjning innan upptäckt av eventuella kvalitetsbrister. Dessutom finns en osäkerhetsfaktor härrörande från den mänskliga faktorn eftersom människans kognitiva förmågor påverkas av dagsform, stressupplevelse, personliga erfarenheter med mera. Examensarbetet har utförts vid Linköpings universitet inom ramen för en magisterutbildning i Ergonomi och MTO (Människa Teknik Organisation). Syftet är att undersöka potentiella vinster vid minskning av den mänskliga faktorn vid övergång från manuell till automatiserad OFP (oförstörande provning). Arbetet består av en litteraturstudie, enkäter till operatörer samt intervjuer med beslutsfattare. Vid detektering, lokalisering, särskiljning, jämförelse och kategorisering spelar perceptionen en stor roll. Den mänskliga faktorn är ett av de huvudelement som påverkar kvaliteten vid oförstörande provning. Operatören är således den största källan till tillförlitlighetsvariation (Dickens &amp; Bray, 1994). OFP - utrustningen visar bara rätt information om den hanteras korrekt. Dessutom behöver informationen tolkas och sammanställas för att en bedömning ska kunna göras. Åtskilliga studier har visat låg detekteringsgrad för flera olika OFP - metoder (runt 50 %) och flera storskaliga forskningsprogram har visat att automatiserad provning är överlägsen den manuella (PISC, NORDEST, NIL, ICON, TIP). Flera studier har visat högre detekteringsgrad (84-90 % jämfört med 50-52 %) och lägre kostnader (minskning med ca 40 %) vid automatisering av provningen. (Wassink &amp; Dijkstra, 2007, Verkooijen, 1998). Knappt 70 operatörer i tillverkningsindustrin har deltagit i denna studie genom att fylla i en enkät om sin arbetssituation. Operatörerna tror själva att stress, trötthet, monotonitet och distraktion i nämnd ordning har negativ påverkan på detekteringsgraden. 97 % av dem tror att automatisering av moment skulle öka andelen funna fel.   Fem beslutsfattare inom olika tillverkningsindustrier har deltagit i studien genom intervjuer kring varför man valt att automatisera. Beslutsfattarna nämner ekonomi och kvalitet som främsta orsaker till att man valt att automatisera provningen. Flera anser att felfrekvensen vid manuell provning var för hög för att man skulle kunna leva upp till kvalitetskraven. Även ergonomi har spelat in eftersom man sparat mycket pengar på minskad sjukfrånvaro. Provningen anses bli mer heltäckande och dokumentationen bättre. Flera uppskattar tids- och kostnadsbesparingar till minst 60 %. Samtliga är nöjda med övergången och kommer att fortsätta automatisera flera moment. / In advanced production industry manual testing is still a common method for ensuring quality of manufactured products. This means apart from the fact that it is often a spot check also a certain delay before possible quality problems are discovered. Additionally there is an uncertainty due to the human factor since the human cognitive behavior is affected by day form, experienced stress, and personal practice etcetera.   This thesis has been carried out at the University of Linköping as a part of a Master in ergonomics degree. The aim is to investigate potential benefits due to less influence of the human factor, when shifting from manual to automated NDT (non destructive testing). The work includes a literature review, operator questionnaires and interviews with decision makers.   At detection, localization, separation, comparison and categorization human perception is of great importance. The human factor is one of the main elements affecting the quality of nondestructive testing. The operator therefore is the main source of reliability variations. The NDE equipment only shows the right information if it is handled the right way. In addition the information needs to be interpreted and put together for an assessment to be made.   Several studies have shown low detection rate for various NDT methods (around 50 %) and a number of large-scale research programs have shown that automated testing is superior to manual (PISC, NORDEST, NIL, ICON, TIP). Various studies have shown higher detection rate (84-90 % compared to 50-52 %) and lower costs (reduction of approx. 40 %) by automation of the testing (Wassink &amp; Dijkstra, 2007, Verkooijen, 1998).   Almost 70 operators in the manufacturing industry took part in this study by answering a questionnaire about their working situation. The operators themselves believe that stress, drowsiness, monotony and distraction, in the order mentioned, have negative effect on the detection rate. 97 % of them think that by automating some elements, the detection rate would increase.   Five decisions makers in the manufacturing industry took part in the study thru interviews concerning the reason for automating the testing. The decisions makers mention economy and quality as main reasons for choosing changeover to automation. Several think that the error frequency by manual testing is too high to be able to live up to the quality demands. Also ergonomics have played a big role since they have saved a lot of money due to less reporting sick. The testing is believed to be more comprehensive and the documentation better. Several estimate time and cost savings to be at least 60 %. All are satisfied with the changeover and want to automate more elements of the production.

The objective of the present study was to explore the correlation between resting metabolic rate (RMR), body composition and physical activity in active and inactive men and women aged 20-30 years. In total, 13 active and 10 inactive women and 8 active and 5 inactive men were enrolled in this study. RMR was measured using an indirect respiratory calorimeter and body composition was obtained using a BodPod, anthropometric measurements (measurements of waist, weight, skin fold thickness etc.) and bioelectrical impedance analysis. From the BodPod were information obtained about fat-free mass (FFM) and fat mass (FM) and from the bioelectrical impedance analysis were data obtained about the total body water (TBW). By combining the data from these methods a three-compartment model could be produced. This gives a better value of the body composition. By using anthropometric measurements the muscle mass (MM) could be calculated. FFM measurements correlate best with RMR for both active men and women and for inactive women. For the inactive men MM correlates best with RMR. In conclusion, comparing the groups as a whole it is seen that the FFM correlates best with RMR for both women and men. Since the muscles are the metabolically active part of FFM it is concluded that muscles affects the RMR value and muscles can in turn be influenced by training.

Snap bean (Phaseolus vulgaris L.) production by large scale commercial producers in Ethiopia is under intensive production and relies on high rates of nitrogen (N) fertilizer and irrigation during the dry season. Despite increasing interest to produce this crop, small scale farmers cannot afford the high cost of N fertilizer. Field and greenhouse experiments were conducted to test snap bean production under a low input production system better suited to small scale resource limited farmers. Field experiments were conducted in 2011 and 2012 under rain fed conditions, and in 2012 under irrigation, at three locations (Debre Zeit, Hawassa, Ziway) representing different climate zones in Ethiopia. This experiment used three N treatments: 0 and 100 kg N ha-1, and inoculation with Rhizobium etli [HB 429], and eight cultivars: Andante, Boston Contender Blue, Lomami, Melkassa 1, Melkassa 3, Paulista and Volta. The general objective of the field experiment was to determine the potential of snap bean production under a low input production system using rhizobium inoculation as the nitrogen source, and use rain fed conditions. Results obtained indicated that rhizobial inoculation and applied inorganic N increased on average the marketable pod yield of snap bean under rain fed conditions by 18 % and 43%, respectively. Nodulation and subsequent N2 fixation was not effective in improving yield or other traits of snap bean pod under irrigation, although applied N increased marketable yield by 33%. Melkassa 1 was the most suitable cultivar for a reduced input production system due to its successful nodulation characteristics, greatest N2 fixation levels and consistently good performance across locations under rain fed conditions. Commercial cultivars possessed the best pod quality characteristics and they yielded better under irrigation. Cultivars interacted with locations to affect pod traits including total soluble solids and concentrations of protein, calcium, and potassium under rain fed conditions. Snap bean cultivrs produced at Debre Zeit and Hawassa were similar in marketable yield and several other traits particularly under rain fed conditions. Zinc (Zn) concentration in pods was greatest at Hawassa both under rain fed and irrigated conditions. Conditions at Debre Zeit were the most conducive for supporting biological N2 fixation for snap bean production. The eight cultivars were also used for a greenhouse study that was evaluated treatments of drought stress of 50% field capacity (50% FC) during the vegetative (V4.4), flowering (R6) and pod formation (R7) developmental stages. Our result showed that drought stresses during reproductive stages (R6 and R7) were the most sensitive stages in deteriorating the quality of snap bean pods. Drought stress increased protein, phosphorus and Zn concentrations but it reduced iron concentration in snap bean pods. All cultivars had a similar response to drought stress. A second greenhouse experiment was conducted to test foliar application of growth regulators: the control, 10-5 M and 10-4 M concentrations of each of abscisic acid (ABA), kinetin and salicylic acid (SA); and two concentrations of yeast extract (4 g l-1 and 8 g l-1), under drought (50% FC) stressed and unstressed conditions. Foliar application of SA on snap bean under greenhouse conditions reduced the impact of drought stress, particularly the pod quality parameters: marketable yield, pod curving, texture and appearance of snap bean pods. However, application of ABA, kinetin and SA reduced pod quality of snap bean under unstressed conditions. In conclusion, pod yield improvement could be achieved by a N2 fixation system under rain fed conditions, which is more sustainable than N fertilizer inputs. Pod quality was also adequate for commercial export production. Rhizobium inoculant can therefore be used as an alternative N source, particularly under low input production system for resource-limited small-scale snap bean producers.

The body composition of female collegiate athletes was measured using the Bod Pod® device. The sample consisted of 75 student athletes, aged 18 to 22 years old. Five sports at the university level were represented, including basketball, gymnastics, soccer, swimming & diving, and soccer. Participants were measured at the preseason and postseason periods. Overall, participants in all five sports were not found to change significantly in total body mass, fat mass, fat free mass, percent body fat, or body mass index from the preseason period to the postseason period at the alpha = 0.05 level. On average, the members from each of the different teams were found to be significantly different from each other for one or more variables. In general, basketball and volleyball players were found to be similar in body composition. The average member on the swimming & diving, soccer, and gymnastics teams was found to vary from the average team member on each of the other teams.