In turbomachinery, extra excitation forces may result from non-idealised operation conditions and may sometime cause excessive vibrations and unsteady rotor motions. The goal of this thesis is to investigate the effects of such excitation forces. The extra excitation forces investigated here are the Thomas/Alford force due to the blade tip clearance change, the steam excitation force caused by the variation of inlet steam speed and state blade trailing wake and the dominant magnetic pull force due to dynamic eccentricity of the rotor. The main research results in this thesis include: (1) The modelling of the Jeffcott rotor and the 600MW steam-turbine generator. The used in-house ??transient?? program can only handle the circular short bearings with the modified short bearing method while the simulated steam-turbine should be supported by tilting pad bearings. The first critical speeds of systems supported by tilting pad bearings are more approaching to the lab data for all four rotor models while that of journal bearing supported systems are normally lower than the real operating critical speed. (2) Applying three sorts of excitation forces into the single-stage rotor-bearing system. The numerical simulation shows that for the model with each single excitation force, all of these three forces need to reach some limit to force the system into the unsteady state. For all the three forces, higher limits are needed if the machine runs at lower running speeds. Furthermore, unbalance loading also can influence the system behaviours. As the unbalance increases, the system will still stay steady while the spectra become noisier, though the amplitude still low comparing to harmonics. (3) Combing three types of excitation forces into the assembled rotor-bearing system. The numerical simulation shows that the assembled system presents similar vibration responses as the single stage rotor-bearing system. Furthermore, these three forces cannot cancel each other and the combination will unstabilise the system. Meanwhile, the influence of the dominant magnetic pull force is less than other two forces.

De manière classique, une caractérisation large signal des amplificateurs de puissance s'effectue en présence d'un signal sinusoïdal CW dans le but de fournir aux concepteurs les informations nécessaires permettant un compromis entre puissance de sortie et rendement en puissance ajoutée. Cependant, Dans les systèmes de communications modernes, les amplificateurs de puissance sont soumis à des signaux de plus en plus complexes (modulations numériques) pour lesquels la linéarité est un critère capital supplémentaire pour les performances globales de ces systèmes. Il est donc indispensable de disposer d'outils de caractérisation fonctionnelle permettant de mesurer l'ensemble de ces critères en présence de ces signaux complexes afin de rendre compte au mieux du comportement du dispositif sous test en le plaçant dans ses conditions réelles de fonctionnement. Ce mémoire présente l'étude et la mise en oeuvre d'un banc de caractérisation fonctionnelle de type "load-pull" pour la mesure de l'ensemble des critères de puissance, rendement et linéarité en présence de tous types de signaux (CW, CW-pulsés, GMSK, QPSK, QAM, etc.). L'ENST dispose d'un banc de mesure "source-pull" et "load-pull" multi-harmonique capable d'optimiser la puissance de sortie et le rendement en puissance ajoutée en mode CW. Ce banc est constitué de réflectomètres six-portes, pour la mesure des impédances et des puissances. Afin de permettre l'utilisation de signaux modulés nous avons implémenté des détecteurs de puissance rapides bas coût à base de diodes Schottky non polarisées pour la détection de puissance au niveau des jonctions six-portes. Pour l'optimisation de la linéarité en plus, nous avons ajouté des modules de contrôle des impédances basses fréquences en entrée et en sortie du composant à tester. Un transistor de puissance MESFET a été testé à la fréquence 1.575 GHz en présence d'un signal modulé QPSK de largeur 1.25 MHz et d'un signal bi-porteuses séparées de 800 kHz pour une polarisation de type A et AB. L'ensemble des mesures effectuées permet d'aboutir aux trois principales conclusions montionnées ci-dessous. Premièrement, les contours "load-pull" d'iso-puissances, d'iso-rendement, d'iso-ACPR et d'iso-produits d'intermodulation d'ordre 3 et 5 montrent que les conditions optimales de puissance, de rendement et de linéarité sont différentes d'où la nécessité de trouver des compromis entre les différents critères. D'autre part, ces résultats montrent qu'il existe une forte corrélation entre l'ACPR et le produit d'intermodulation d'ordre 3 en classe A mais pas en classe AB. De toute façon, quel que soit le degré de corrélation, il apparaît difficile de prédire l'ACPR à partir de la connaissance des produits d'intermodulation. Deuxièmement, l'effet des impédances de source BF n'est notable qu'en classe AB dans la zone de saturation. Cet effet se fait sentir uniquement sur la linéarité (variation de 5 dB pour l'ACPR). Finalement, l'effet des impédances de charge BF apparaît quelle que soit la classe de fonctionnement avec évidemment un effet très prononcé pour les classes fortement non-linéaire comme la classe AB pour laquelle on a observé des variations de 5 à 20 dB pour l'ACPR sur toute la dynamique de mesure. Notons que l'impédance optimale n'est pas obligatoirement un court-circuit, et que cette impédance optimale n'est pas toujours l'impédance minimisant la dissymétrie. Par ailleurs, ces impédances ont également une grande influence sur le rendement (variation observée de 10 points) et sur la puissance de sortie (variation de 1 dB).

<p>As an increasing number of people are logging on to the internet to do their shopping, it is imperative for a site to be accessible and usable. Nielsen’s heuristic method is one esteemed method that many web site developers use in their design work. One study suggests that online shopping needs most improvement with the heuristics “User control and freedom” where an undo button often is lacking and in ‘Help and Documentation’ where the user may not easily switch between their work and the help. The study, however, has been made on grocery shops alone.</p><p>The following study adopts the results of the past study as hypotheses and investigates if they hold true for another type of online shopping site – women’s apparel. The results of the study confirm that these two heuristics indeed are the two most troublesome. However, for the biggest usability disaster under each, the results are either inapplicable or only lend weak support. The following results lend more support to a possible generalization for all online sites and better awareness among software developers of online shopping sites. Yet a more consistent base of common usability disasters under these two specific heuristics needs to be developed.</p>

This field study examined relationships of income and life satisfaction among retirees, their perceptions of whether their decisions to retire were voluntary or involuntary, and their stated reasons for retiring: “push” (to exit unsustainable work situations) or “pull” (to pursue more attractive options). Based on prior research, hypotheses predicted that voluntary / involuntary choice would moderate the relationship of income and life satisfaction, and that the relationship would vary as a function of "push" vs. "pull" reasons for retiring. A screened, national sample of 1,043 U.S. retirees completed an online survey that assessed satisfaction with multiple life domains, reason for retiring, demographic characteristics, family income, and perceived financial control. Results showed that voluntary retirees had, on average, higher income, life satisfaction, and perceived financial control than those who saw their retirements as involuntary. Type of reason for retirement did moderate the relationship between income and life satisfaction, but in an unexpected way. Based on decades of research on the relationship of control and stress, the hypothesis predicted the correlation between income and life satisfaction would be weakest in voluntary "pull" retirees, and strongest in the involuntary group. Instead, the relationship was strongest among voluntary "push" retirees (r=+.35). These surprising results highlight the importance of further research on perceived control over retirement on common predictors of life satisfaction in retirement.

‘Internationalisation of higher education’ is considered a significant issue in many countries.One effective way to achieve internationalisation is by having an exchange study program. Thisis something which has been promoted by universities all around the globe. It has been foundthat the experience of studying abroad is beneficial to the students. There has been a trend ofincreasing number of students going to study abroad. In Sweden, Jönköping InternationalBusiness School (JIBS) is one of the most internationalised business schools that promoteexchange studies extensively. To promote study abroad it is important to know what motivatesand influences the students to go on exchange. There has been previous research oninternationalisation and push-pull factors of student mobility which acted as a guideline for thisthesis. Thus it was appealing to study the reasons behind the phenomenon of students goingabroad for exchange studies.The purpose of this paper is to explore the push-pull factors influencing student’s destinationchoice for exchange study abroad. JIBS is the institution where the case study was conducted.The empirical data have been gathered by using a qualitative approach combining face-to-faceinterviews and focus groups with international exchange students and Swedish students. Toanalyse the findings, theories relating to marketing communications in service and productattribution were used.The results derived from the empirical findings show the push-pull factors which motivatestudents to go on exchange. The initial push factor is the promotion and encouragement tostudents for studying abroad by the university. Exchange studies helps to enhance students’personal development with intercultural communication, practicing language skills andtravelling. These skills and experiences add value to their CV.On the other hand the pull factors which the students take into consideration for deciding ontheir host countries and institutions are geographic location, weather, culture, and the economicand social position of the country. Living cost and the education system which includeslanguage used, courses offered, perceived image, communication and cooperation andrecommendations are factors influencing the choices of a student’s decision on the destinationfor studying abroad. The authors in this thesis summarised their findings in a model of pushpullfactors which is specialised only for exchange students. The process of considering thesefactors leads to the outcome of choosing the destination for studying abroad. The authorsbelieve the results of this study can be applied on other universities for further research andmay be appropriate for its own case to focus on areas where it needs to improve.ii

As an increasing number of people are logging on to the internet to do their shopping, it is imperative for a site to be accessible and usable. Nielsen’s heuristic method is one esteemed method that many web site developers use in their design work. One study suggests that online shopping needs most improvement with the heuristics “User control and freedom” where an undo button often is lacking and in ‘Help and Documentation’ where the user may not easily switch between their work and the help. The study, however, has been made on grocery shops alone. The following study adopts the results of the past study as hypotheses and investigates if they hold true for another type of online shopping site – women’s apparel. The results of the study confirm that these two heuristics indeed are the two most troublesome. However, for the biggest usability disaster under each, the results are either inapplicable or only lend weak support. The following results lend more support to a possible generalization for all online sites and better awareness among software developers of online shopping sites. Yet a more consistent base of common usability disasters under these two specific heuristics needs to be developed.

Medical tourism is a global emerging industry and is an important component of tourism., and operates on the basis of both individual and regional level. Medical tourism refers to a vacation that involves traveling across international borders to obtain a broad range of medical services. It usually includes leisure, fun, and relaxation activities, as well as wellness and health-care service. Patients who seek to reduce their health-care expenditures travel to medical centers in other countries to obtain dental, medical, and surgical services that are less expensive than those at home. Medical tourism can be defined as the provision of cost-effective medical care to patients in collaboration with the tourism industry. This process is usually facilitated by the private medical sector, whereas both the private and public sectors are involved in the tourism industry. By traveling abroad to have surgery or other medical treatment, medical tourists also take advantage of the opportunity to visit a popular travel destination, thus combining health care with a vacation. The aim of this thesis can be summarized as to provide a deep understanding of what factors are essential and require the phenomenon of Medical Tourism in terms of Swedish travel patterns. The research questions aims also to develop a competitive and sustainable business concept within the frames of the current market. The results of this paper aims to proof in addition to the knowledge gained from literature and precedent research, to use a case study methodology to provide a valuable insight for both academics and practitioners into the process of further research, pursue studies and practicing approaches within the context of Medical Tourism. Results indicate that , the factors that characterize the Swedish travel patterns within medical tourism is price, availability and service, quality and the ability of combining holidays with treatment. Medical tourism phenomena can be explained using for components of medical tourism system: medical tourists, medical tourist regenerating regions, medical tourist destinations regions and medical tourism industries. Each component is a basic component of the medical tourism system, and each is mutually connected and interdependent in their mechanisms. Medical tourists require the four areas of the services which are needed for successful medical tourism. Even if the components of service influence each other, in general medical tourism agency plays a major role in arranging the schedule of medical tourists for the for service components. Medical service may be the most important factor which the medical tourists consider when they choose a destination for medical tourism. Accommodation, food and beverage, tourism experiences, and government regulations and socio-cultural factors are also crucial factors affecting the choice of a medical tourism destination. Quality management and Product differentiation is to strategies that both interrelate with each other and benefits both medical tourism efficiencies and medical tourists. They are important strategies from both a sustainable and economic perspectives as Quality management maximizes the internal force of every level in medical tourism clinics in order to satisfy their patients, meanwhile Product differentiation aims to develop sustainable marketing approaches to attract potential medical tourists and create competitive offers.

Proactive ergonomics is generally considered to be a more efficient and cost effective way of designing working environments than reactive ergonomics. It often requires preemptively selecting working postures and forces to reduce potential injury risk. One major issue with proactive ergonomic design is correctly identifying the true manual forces that will be required of a worker to complete defined tasks. Typically, these forces are represented as in direct opposition to the forces required by a particular task. However, this is likely an oversimplification as forces often act in different directions than the task-required direction to increase required force level, enhance balance and reduce joint moments, depending on specific experimental conditions. This study aims to quantify these off-axis forces as they change with different required on-axis force intensities. This thesis evaluated the effects of force intensity on the presence of off-axis forces across four conditions, which included free and constrained postures, and with and without off-axis force. Eighteen female subjects performed static, unilateral, manual pushing and pulling exertions while seated and were limited to force contributions from the right upper extremity. Hand forces and location of bony landmarks were collected from each subject and force intensity consisted of both maximal and submaximal levels (5% to 50% of the maximum producible on-axis force in increments of 5%). All principle direction forces were scaled to the on-axis force level and anatomically relevant joint moments scaled to the maximum capacity joint moment. The main objective of this study was to analyze off-axis force production as force intensity was increased under various constraint conditions. The highest maximum on-axis force was in the fully free condition (off-axis force allowed and posture unconstrained) and as conditions became more constrained for both pushing and pulling exertions, maximum on-axis force production decreased (p=<0.0001). For submaximal exertions in the free posture, participants used off-axis forces to target the shoulder flexion-extension moment by pushing increasingly upwards (p=0.0122) and to the left by 5.6% on-axis (p=0.0025), and by pulling 12.6% on-axis downward (p=<0.0001) and 4.7% on-axis rightward (p=0.0024) compared to when off-axis force was not allowed. When comparing the free to the constrained posture while allowing off-axis force, participants pushed downwards instead of upwards by a difference of 12.9% on-axis (p=0.0002) and pulled less downward (becoming slightly upward) by an increasing difference (p=0.0002) and from decreasing to increasing rightward (p=0.0006). These changes in off-axis force showed a unifying strategy of using less shoulder flexion-extension strength by targeting wrist and elbow moments for pushing and pulling exertions. When in the constrained posture allowing and not allowing off-axis force resulted in more internal elbow flexion (p=0.0003) moment during pushing, and less internal shoulder flexion (p=0.0092), more internal shoulder adduction (p=0.0252), more to less internal elbow supination (p=0.0415), and increasingly less internal wrist flexion (p=0.0296) moments during pulling, which verified previously observed strategies. Finally, for both maximal and submaximal exertions, pulling was more sensitive to changes in off-axis forces compared to pushing which was more sensitive to postural flexibility. In conclusion, the underlying principles as to how and why off-axis forces change provides valuable knowledge to ergonomists so that they can more accurately predict force production in workplace design, ultimately reducing the potential for injury.

The role of branding in building distribution relationships has attained increased attention in the marketing literature lately and several studies have shown that branding is an effective tool for building stronger relationships between manufacturers and their distribution partners. Unfortunately these findings fail to explain how channel push strategies work independently of consumer pull strategies when it comes to building strong manufacturer brands. On one hand, it is asserted that close interaction between brand representatives and distribution channel members is a prerequisite for success, while it on the other hand is asserted that direct communication to end users is just as important. In terms of managerial implications this has often led to vague recommendations in crafting a "perfect blend" between push and pull strategies.These recommendations constitute a status quo, where marketing managers in manufacturing firms have been placed in between two strategies without clear recommendations on how they work independently of each other. This status quo is a problem in both academic research and managerial practice since distribution channel relationships are seen as an increasingly important source of competitive advantage. As a result, the theoretical foundation of a blended strategy might be reprioritized in advantage for better relationships with distribution channel members, which in effect make push efforts the prioritized channel for manufacturer brand management.This master thesis gives all its attention to channel push branding and provides essential insights into how a brand is built in the minds of distributors, resellers and end-users, through a channel-push strategy. A single case study design is used, investigating a telecom-brand focused solely on a channel push strategy. The investigation concerns the brand identity as well as interviews with distributors, resellers and end-users. The studied brand is analyzed through Aaker's (2002) conceptualization of consumer based brand equity, consisting of brand awareness, brand associations, perceived quality and brand loyalty. Although an equity model is used, the goal is not to assess brand value, rather to investigate how brand equity is built through a strict channel push strategy.Although this case illustrates both challenges and limitations, I strongly argue against the assertion that strict push strategies are something of the past. The studied brand is filled with relevant associations and functional attributes and has only suffered minor diversities between different intermediaries and regions. However, this case also shows that channel push branding is a complex procedure that requires careful and specific considerations. Main areas which should be considered are; limitations in awareness creation, difficulties in building brand associations, dependence of interpersonal relations and the activity of the end-user-brand relationship. My main contribution with this case study is a rich description of the underlying phenomena which constitute these considerations. Distribution channel relationships are an increasingly important source of competitive advantage, and I believe that this case provides a new perspective on channel push branding, both to practitioners and to researchers.

When designing work tasks, one goal should be to enable postures that maximize the force capabilities of the workers while minimizing the overall muscular demands; however, little is known regarding specific shoulder tissue loads during pushing and pulling. This study quantitatively evaluated the effects of direction (anterior-posterior pushing and pulling), handle height (100 cm and 150 cm), handle orientation (vertical and horizontal), included elbow angle (extended and flexed) as well as personal factors (gender, mass and stature) on hand force magnitudes, shoulder and L5/S1 joint moments, normalized mean muscle activation and electromyography (EMG)/force ratios during two-handed maximal push and pull exertions. Twelve female and twelve male volunteers performed maximal voluntary isometric contractions under 10 push and pull experimental conditions that emulated industrial tasks. Hand force magnitudes, kinematic data and bilateral EMG of seven superficial shoulder and trunk muscles were collected. Results showed that direction had the greatest influence on dependent measures. Push exertions produced the greatest forces while also reducing L5/S1 extensor moments, shoulder moments with the 150 cm height and overall muscular demands (p < 0.0001). The 100 cm handle height generated the greatest forces (p < 0.0001) and reduced muscular demands (p < 0.05), but were associated with greater sagittal plane moments (p < 0.05). Females generated, on average, 67% of male forces in addition to incurring greater muscular demands (p < 0.05). The flexed elbows condition in conjunction with pushing produced greater forces with reduced overall muscular demands (p < 0.0001). Furthermore, horizontal handle orientation caused greater resultant moments at all joints (p <. 0.05) The results have important ergonomics implications for evaluating, designing or modifying workstations, tasks or equipment towards improved task performance and the prevention of musculoskeletal injuries and associated health care costs.