This study develops a method to simulate a full-scale inertia friction weld with a sub-scale specimen and modifies a direct drive friction stir welder to perform the welding process. A torque meter is fabricated for the FSW machine to measure weld torque. Machine controls are modified to enable a force control during the IFW process. An equation is created to measure weld upset due to deflection of the FSW machine. Data obtained from a full-scale inertia friction weld are altered to account for the geometrical differences between the sub-scale and full-scale specimens. The IFW are simulated with the sub-scale specimen while controlling spindle RPM and matching weld power or weld RPM. The force used to perform friction welding is scaled to different values accounting for specimen size to determine the effects on output parameters including: HAZ, upset, RPM, torque, power and energy of the weld. Increasing force has positive effects to upset, torque, power and energy of the welds, while reducing the size of the HAZ.

Central banks use a series of relatively small interest rate changes in adjusting their monetary policy stance. This persistence in interest rate changes is well documented by empirical monetary policy reaction functions that feature a large estimated coefficient for the lagged interest rate. The two hypotheses that explain the size of this large estimated coefficient are monetary policy inertia and serially correlated macro shocks. In the first part of my dissertation, I show that the effect of inertia on the Federal Reserve’s monthly funds rate adjustment is only moderate, and smaller than suggested by previous studies. In the second part, I present evidence that the temporal aggregation of interest rates puts an upward bias on the size of the estimated coefficient for the lagged interest rate. The third part of my dissertation is inspired by recent developments in the housing market and the resulting effect on the overall economy. In this third essay, we show that high loan-to-value mortgage borrowing reduces the effectiveness of monetary policy.

The purpose of this dissertation is to describe, explain and understand how slowness appeared when some decisions were made in the area of welfare policy and how this slowness was eliminated. The study focuses on major changes. It is argued that such changes follow another logic than small gradual adjustments. Four breaking points have been selected for a deeper analysis: the pension policy decisions of 1913 and 1994 and the housing policy decisions of 1935 and 1992. These decisions led to the emergence of fundamentally new institutional structures concerning the relation between the central government and the citizens. The study shows that an established institutional structure within a welfare policy area generated mental constructs and decision rules that governed political decision-making. This governance resulted in slowness in the form of lengthy decision-making processes. The fundamental institutional structure was being altered only when the mental constructs were broken down. A common feature was that the decisions were first made when discontent with the prevailing order became so strong that it overwhelmed the fear of a new institutional structure. The general tendency was also to shape the fundamental changes in relation to the citizens so that the changes could be portrayed as small. The established mental constructs are the determining explanation for slowness. The interest organizations played a secondary role, as their interests are shaped in accordance with the mental constructs. Their resistance was declined at the same time when the mental constructs were broken down. The individuals – agents of change – that constantly worked for the change of system in reality appear to be significantly more interesting than hindering organization. Their influence showed a recurring pattern.

Innebandy är en växande idrott, som framför allt utövas i Sverige, Finland och Schweiz, men där väldigt lite forskning ännu finns publicerad. Tidigare studier inom ishockey och baseboll har visat att träning med viktmanipulerad utrustning förbättrat bland annat greppstyrka och svinghastigheten av slagträ i baseboll. Annan forskning har visat på att det är en förbättring i det neuromuskulära samspelet snarare än ökad muskelmassa som förbättrat prestationen vid dynamisk motståndsträning. Skotthastigheten anses vara en viktig faktor inom innebandy för prestationen och eftersom det inom baseboll har visats att viktmanipulerad utrustning kan förbättra svinghastigheten så vore det intressant att se om samma resultat kan uppnås inom innebandy. Syftet med studien var att undersöka effekten av innebandyträning med en viktmanipulerad innebandyklubba med avseende på dragskottshastighet och greppstyrka hos manliga innebandyspelare samt undersöka korrelationen mellan dragskottshastighet och greppstyrka. Även testpersonernas subjektiva uppfattning av träningen med den viktmanipuleradeutrustningen undersöktes. Testgruppen bestod av 13 stycken 17-åriga manliga innebandyspelare. Under en sex veckors period genomförde testpersonerna 30 minuter av sin vanliga innebandyträning med den viktmanipulerade klubban (40 gram tyngre) tre gånger i veckan. Dragskotten filmades med en höghastighetskamera (Casio Exilim EX-FH25) med 250 fps och analyserades sedan i Dartfish för att mäta hastigheten. För att fastställa greppstyrkan användes en handdynamometer (Jamar – Baseline Hydraulic Hand Dynamometer). Träningen resulterade i en signifikant skillnad hos testpersonernas greppstyrka i den nedre handen på klubban (p<0,05). Däremot hittades ingen signifikant skillnad för den övre handens greppstyrka eller dragskottshastigheten. Studien visade heller inte på någon korrelation mellan dragskottshastighet och greppstyrka hos testpersonerna. Testpersonerna hade olika åsikter kring hur den extra tyngden påverkade innebandytekniken.De funna resultaten indikerar att träning med viktmanipulerad utrustning i innebandy signifikant förbättrar spelarnas greppstyrka i den nedre handen. Den ökade kraftutvecklingen kan eventuellt förklaras av ett ökat neuromuskulärt samspel. Studien ger en ökad förståelse för hur dynamisk motståndsträning kan implementeras i den dagliga innebandyträningen, vilket kan tillämpas vid planeringen av träningsprogram. / Floorball is a sport with increasing number of participants, which has not been studied extensively according to the literature. Previous studies on ice hockey and baseball have shown that training with weight manipulated equipment improved grip strength and swing speed. Other research has shown that the increased performance with dynamic resistance training rather occurs from the improvements in the neuromuscular facilitation than an increase in muscle mass. In floorball shooting velocity is considered to be an important factor of the performance. Since it has been shown in baseball that training with weight manipulated equipment can improve the bat velocity, it would be interesting to see if the same results can be found in floorball. The purpose of this study was to investigate the effect of grip strength and drag shot velocity in floorball training with a weight manipulated floorball stick. The study also investigated the relationship between grip strength and drag shot velocity. The test subjects’ subjective perception about the training method was also investigated. Thirteen 17-year-old male floorball players participated in the study. During a six weeks period the subjects used the weight manipulated equipment during 30 minutes, three times per week during their regular team practice. 40 grams lead tape was attached to the player's equipment to increase the resistance. The drag shots were filmed with a high speed camera (Casio Exilim EX-FH25) at 250 fps. The drag shot velocity was analyzed in Dartfish. To assess grip strength a hand dynamometer (Jamar - Baseline Hydraulic Hand Dynamometer)was used. The training resulted in a significant increase for the subjects’ grip strength in the lower hand on the stick (p <0,05). The study found no significant difference for the upper hand grip strength or drag shot velocity. No correlation between drag shot velocity and handgripstrength among the subjects were found. Conclusion: The results found in this study indicate that training with weight manipulated equipment can significantly improve the player’s lower hand grip strength. The results can eventually be explained by more effective fiber recruitment in the muscles. Studying floorball can contribute to increase the interest in research on floorball and increase the understanding for how dynamic resistance training can be incorporated in daily floorball practice.

Static characteristics and rotordynamic coefficients were experimentally determined for a four-pad tilting-pad journal bearing with ball-in-socket pivots in loadbetween- pad configuration. A frequency-independent [M]-[C]-[K] model fit the measurements reasonably well, except for the cross-coupled damping coefficients. Test conditions included speeds from 4,000 to 12,000 rpm and unit loads from 0 to 1896 kPa (0 to 275 psi). The test bearing was manufactured by Rotating Machinery Technology (RMT), Inc. Though it has a nominal diameter of 101.78 mm (4.0070 in.), measurements indicated significant bearing crush with radial bearing clearances of 99.6 μm (3.92 mils) and 54.6 μm (2.15 mils) in the axes 45º counterclockwise and 45º clockwise from the loaded axis, respectively. The pad length is 101.6 mm (4.00 in.), giving L/D = 1.00. The pad arc angle is 73º, and the pivot offset ratio is 65%. The preloads of the loaded and unloaded pads are 0.37 and 0.58, respectively. A bulk-flow Navier-Stokes model was used for predictions, using adiabatic conditions for the bearing fluid. Because the model assumes constant nominal clearances at all pads, the average of the measured clearances was used as an estimate. Eccentricities and attitude angles were markedly under predicted while power loss was under predicted at low speeds and very well predicted at high speeds. The maximum detected pad temperature was 71ºC (160ºF) and the rise from inlet to maximum bearing temperature was over predicted by 10-40%. Multiple-frequency force inputs were used to excite the bearing. Direct stiffness and damping coefficients were significantly over predicted, but addition of a simple stiffness-in-series model substantially improved the agreement between theory and experiment. Direct added masses were zero or negative at low speeds and increased with speed up to a maximum of about 50 kg; they were normally greater in the unloaded direction. Although significant cross-coupled stiffness terms were present, they always had the same sign. The bearing had zero whirl frequency ratio netting unconditional stability over all test conditions. Static stiffness in the y direction (obtained from steadystate loading) matched the rotordynamic stiffness Kyy (obtained from multiple-frequency excitation) reasonably at low loads but poorly at the maximum test load.

This thesis documents the studies conducted in deriving a mathematical model representing the dynamics of a maneuvering ship to be implemented as part of an interactive real-time simulation system, as well as the details and results of the implementation process itself. Different effects on the dynamics of ship motions are discussed separately, meaning that the effects are considered to be applied to the system one at a time and they are included in the model simply by the principle of superposition. The model is intended to include the hydrodynamic interactions between the ship hull and the ocean via added mass (added inertia), damping and restoring force concepts. In addition to these effects, which are derived considering no incident waves are present on the ocean, the environmental disturbances, such as wind, wave and ocean current are also taken into account for proposing a mathematical model governing the dynamics of the ship. Since the ultimate product of this thesis work is a running computer code that can be integrated into an available simulation software, the algorithm development and code implementation processes are also covered. Improvements made on the implementation to achieve &ldquo / better&rdquo / real-time performance are evaluated comparatively in reference to original runs conducted before the application of improvement under consideration. A new method to the computation of the wave model that allows faster calculation in real-time is presented. A modular programming approach is followed in the overall algorithm development process in order to make the integration of new program components into the software, such as a new hull or propulsion model or a different integrator type possible, easily and quickly.

The in-situ examination of historical structures for diagnostic and monitoring purposes is a troublesome work that necessitates the use of non-destructive investigation (NDT) techniques. The methods of quantitative infrared thermography (QIRT) and ultrasonic testing have distinct importance in this regard. The key concern of the study was developing the in-situ use of QIRT for assessment of stone masonry wall sections having different sublayer(s) and failures. For that purpose, the non-destructive in-situ survey composed of QIRT and ultrasonic testing was conducted on a 16th century monument, Cenabi Ahmet PaSa Camisi, suffering from structural cracks, dampness problems and materials deterioration. The combined use of these two methods allowed to define the thermal inertia characteristics of structural cracks in relation to their depth. The temperature evolution in time during the controlled heating and cooling process was deployed for the cracks/defects inspection. The superficial and deep cracks were found to have different thermal responses to exposed conditions which made them easily distinguishable by QIRT analyses. The depth of cracks was precisely estimated by the in-situ ultrasonic testing data taken in the indirect transmission mode. The inherently good thermal resistivity of the wall structure was found to have failed due to entrapped moisture resulting from incompatible recent plaster repairs. The IRT survey allowed to detect the wall surfaces with different sublayer configurations due to their different thermal inertia characteristics. The knowledge and experience gained on the experimental set-ups and analytic methods were useful for the improvement of in-situ applications of QIRT and ultrasonic testing.

Thermal mass can be successfully implemented in the hot‐humid region of Austin, TX especially when well designed and with supplementary aids like nightcooling and day‐lighting. This study shows that in some situations thermal mass can be actually more beneficial at reducing electricity demands in hot‐humid regions than in the hot‐dry regions that are so emphasized in the literature. / text

Les écoulements rampants, recirculants et instationnaires d'un fluide viscoplastique autour d'un cylindre ont été étudiés.Numériquement, les morphologies des écoulements, la localisation des zones rigides, les champs de contraintes et pression autour du cylindre ainsi que le coefficient de traînée, ont été déterminés sur un large domaine des nombres de Reynolds et d'Oldroyd.Expérimentalement, les fluides étudiés sont des gels de polymère Carbopol®. Le comportement élastoviscoplastique de ces gels a été modélisé par une loi d'Herschel-Bulkley adaptée. Le montage expérimental conçu et réalisé a été validé par l'étude de l'écoulement d'un fluide newtonien autour d'un cylindre et la mise en place d'une procédure adaptée pour les fluides à seuil.On a pu constater l'influence des conditions d'interface avec l'apparition d'une morphologie de lâchers de tourbillons simultanés et symétriques.

Contemporary organisations face a raft of challenges in coping with competing demands and rapidly changing environments. With these demands and changes comes the need for those within the organisation to be adequately skilled to meet these challenges both now and into the future. There is a growing concern that the rate of change is such that learning will not be sufficient and that individuals will need to be skilled in unlearning or letting go of past practice and behaviour. This research investigated individual unlearning as it applies in the workplace, and enabled the development of a process model of unlearning that provides specific indication of factors affecting unlearning during times of change. In particular, this thesis highlights the critical importance of elements of a more personal and affective nature; often referred to as "soft" issues. Six key factors at the level of the individual were identified as impacting unlearning; positive prior outlook, individual inertia, feelings and expectations, positive experience and informal support, understanding the need for change, and assessment of the new way. Two factors emerged from the organisational level that also impact unlearning; organisational support and training and history of organisational change. Many change efforts will fail because of lack of attention to individuals, how they unlearn and the level of feelings and expectations that accompany change. This research demonstrates that organisations must provide resources and education to provide both those in supervisory roles and those impacted by change with the necessary skills to unlearn and to embrace change at an individual level.