Stiffness based trajectory planning and feedforward based vibration suppression control of parallel robot machines

The dissertation proposes two control strategies, which include the trajectory planning and vibration suppression, for a kinematic redundant serial-parallel robot machine, with the aim of attaining the satisfactory machining performance. For a given prescribed trajectory of the robot's end-effector in the Cartesian space, a set of trajectories in the robot's joint space are generated based on the best stiffness performance of the robot along the prescribed trajectory. To construct the required system-wide analytical stiffness model for the serial-parallel robot machine, a variant of the virtual joint method (VJM) is proposed in the dissertation. The modified method is an evolution of Gosselin's lumped model that can account for the deformations of a flexible link in more directions. The effectiveness of this VJM variant is validated by comparing the computed stiffness results of a flexible link with the those of a matrix structural analysis (MSA) method. The comparison shows that the numerical results from both methods on an individual flexible beam are almost identical, which, in some sense, provides mutual validation. The most prominent advantage of the presented VJM variant compared with the MSA method is that it can be applied in a flexible structure system with complicated kinematics formed in terms of flexible serial links and joints. Moreover, by combining the VJM variant and the virtual work principle, a systemwide analytical stiffness model can be easily obtained for mechanisms with both serial kinematics and parallel kinematics. In the dissertation, a system-wide stiffness model of a kinematic redundant serial-parallel robot machine is constructed based on integration of the VJM variant and the virtual work principle. Numerical results of its stiffness performance are reported. For a kinematic redundant robot, to generate a set of feasible joints' trajectories for a prescribed trajectory of its end-effector, its system-wide stiffness performance is taken as the constraint in the joints trajectory planning in the dissertation. For a prescribed location of the end-effector, the robot permits an infinite number of inverse solutions, which consequently yields infinite kinds of stiffness performance. Therefore, a differential evolution (DE) algorithm in which the positions of redundant joints in the kinematics are taken as input variables was employed to search for the best stiffness performance of the robot. Numerical results of the generated joint trajectories are given for a kinematic redundant serial-parallel robot machine, IWR (Intersector Welding/Cutting Robot), when a particular trajectory of its end-effector has been prescribed. The numerical results show that the joint trajectories generated based on the stiffness optimization are feasible for realization in the control system since they are acceptably smooth. The results imply that the stiffness performance of the robot machine deviates smoothly with respect to the kinematic configuration in the adjacent domain of its best stiffness performance. To suppress the vibration of the robot machine due to varying cutting force during the machining process, this dissertation proposed a feedforward control strategy, which is constructed based on the derived inverse dynamics model of target system. The effectiveness of applying such a feedforward control in the vibration suppression has been validated in a parallel manipulator in the software environment. The experimental study of such a feedforward control has also been included in the dissertation. The difficulties of modelling the actual system due to the unknown components in its dynamics is noticed. As a solution, a back propagation (BP) neural network is proposed for identification of the unknown components of the dynamics model of the target system. To train such a BP neural network, a modified Levenberg-Marquardt algorithm that can utilize an experimental input-output data set of the entire dynamic system is introduced in the dissertation. Validation of the BP neural network and the modified Levenberg- Marquardt algorithm is done, respectively, by a sinusoidal output approximation, a second order system parameters estimation, and a friction model estimation of a parallel manipulator, which represent three different application aspects of this method.

Westerners in search of the legendary potion : ayahuasca travel in the borderland between tourism and pilgrimage

The thesis examines the phenomenon most commonly known as “ayahuasca tourism” – i.e. the practice of westerners traveling to South America and partaking in ceremonies in which a powerful entheogenic brew, ayahuasca, is consumed. While this popular phenomenon has been steadily increasing during the last decades, it has, however, been insufficiently studied by scholars. An important question which has not been properly addressed in earlier studies is how ayahuasca tourism relates to the wider occurrence of travel and how it should be perceived with reference to the theoretical frameworks on the subject of travel. Drawing on theories regarding pilgrimage and tourism, the main purpose of this thesis is to examine the relationship between ayahuasca tourism and the broader spectrum of travel. In particular, the study tests the designations “pilgrimage”, “religious tourism” and “spiritual tourism” with reference to ayahuasca tourism. Utilizing earlier literature as well as ayahuasca tourists‟ reports obtained from an Internet forum as a basis for analysis, I search for a suitable terminology to be used for the phenomenon. The study lays special emphasis on the protagonists‟ motivations, experiences and outcomes in order to take note of various aspects of the wide-ranging occurrence of ayahuasca tourism. Key findings indicate that ayahuasca tourism is best understood as a combination of pilgrimage and tourism. On the basis of the analysis I argue that ayahuasca tourism should be labeled as “pilgrimage” and/or “spiritual tourism”, and the tourists respectively as “pilgrims” and/or “spiritual tourists”. The category of “religious tourism/tourist”, on the other hand, turns out to be an inappropriate designation when describing the phenomenon. In general, through my study I show that the results are consistent with the present trend in the study of travel to perceive pilgrimage and tourism as theoretically similar phenomena. The study of ayahuasca tourism serves thus as living proof of contemporary travel, in which the categories of pilgrimage and tourism are often indistinguishable. I suggest that ayahuasca tourism is by no means exceptional on this point, but can rather be used as an illustration of modern travel forms on a general level. Thus, the present study does not only add to the research of ayahuasca tourism, but also provides additional insights into the study of travel.

Oral verrucous lesions – a search for PVL

Proliferatiivinen verrukoottinen leukoplakia (PVL) esiintyy yhtenä laajana tai useampana verrukoottisena, valkoisena muutoksena suun limakalvoilla. PVL on aggressiivinen limakalvomuutos, joka ei usein vastaa hoitoihin, uusii herkästi ja sillä on muita leukoplakioita suurempi pahanlaatuistumistaipumus. Tutkimuksen tarkoitus on lisätä tietoa PVL:sta ja sen ilmentymisestä ja kehittymisestä sekä arvioida kriittisesti PVL:n diagnostiikkaa. Systemaattinen kirjallisuuskatsaus suoritettiin etsimällä Pubmed-tietokannan kirjallisuushaulla kaikki englannin kielellä raportoidut ja vertaisarvioidut PVL- potilastapaukset 2000 – 2013. PVL voi histologisesti esiintyä myös verrukoottisena hyperplasiana (VH), joten myös nämä tapaukset sisällytettiin aineistoon. Kaikkiaan 54 artikkelia täytti sisäänottokriteerit. Näissä oli yhteensä 388 PVL- ja 848 VH-tapausta. Lisäksi kerättiin kaikki Turun yliopiston hammaslääketieteen laitoksen suupatologian osastolla histologisesti diagnosoidut vastaavat suun VH-muutokset 2000 – 2013. Kirjallisuudesta havaittiin, että PVL esiintyi useammin naisilla (2,2 : 1), kun taas VH esiintyi useammin miehillä (1 : 3,8). Tupakointi ei näyttänyt liittyvän PVL:aan (30 %), kun taas VH:aan se näytti selkeämmin liittyvän (83 %). PVL:n yleisin sijainti oli ikenellä (59 %) ja suurin osa VH-muutoksista esiintyi posken limakalvolla (51 %). PVL-potilaista 47 %:lla ja VH-potilaista 5 %:lla todettiin seurannassa pahanlaatuinen kasvain. Turun yliopiston suupatologian osastolla diagnosoituja VH-tapauksia oli 13 vuoden aikana 29. Naisten osuus sairastuneista oli suurempi kuin miesten (1,4 : 1). Muutokset esiintyivät yleisimmin kielen limakalvolla (48 %) ja poskessa (34 %). Yhdessä tapauksessa kehittyi pahanlaatuinen kasvain (3 %). Tutkimuksessa todettiin, että PVL- ja VH-muutokset poikkeavat toisistaan sukupuolijakauman, tupakoinnin ja pahanlaatuistumisen osalta. Ongelmana katsauksessa olivat tietojen puutteellisuus ja raportoinnin heterogeenisyys kirjallisuudessa. PVL- ja VH-tutkimuksessa tulisikin panostaa yhteneviin diagnostisiin kriteereihin, jotta materiaalit olisivat vertailukelpoisia. Potilaan kannalta PVL:n ja VH:n varhainen diagnosointi ja huolellinen seuranta ovat olennaisen tärkeitä asioita.

Thick Section Laser Beam Welding of Structural Steels: Methods for Improving Welding Efficiency

Laser beam welding (LBW) is applicable for a wide range of industrial sectors and has a history of fifty years. However, it is considered an unusual method with applications typically limited to welding of thin sheet metal. With a new generation of high power lasers there has been a renewed interest in thick section LBW (also known as keyhole laser welding). There was a growing body of publications during 2001-2011 that indicates an increasing interest in laser welding for many industrial applications, and in last ten years, an increasing number of studies have examined the ways to increase the efficiency of the process. Expanding the thickness range and efficiency of LBW makes the process a possibility for industrial applications dealing with thick metal welding: shipbuilding, offshore structures, pipelines, power plants and other industries. The advantages provided by LBW, such as high process speed, high productivity, and low heat input, may revolutionize these industries and significantly reduce the process costs. The research to date has focused on either increasing the efficiency via optimizing process parameters, or on the process fundamentals, rather than on process and workpiece modifications. The argument of this thesis is that the efficiency of the laser beam process can be increased in a straightforward way in the workshop conditions. Throughout this dissertation, the term “efficiency” is used to refer to welding process efficiency, specifically, an increase in efficiency refers an increase in weld’s penetration depth without increasing laser power level or decreasing welding speed. These methods are: modifications of the workpiece – edge surface roughness and air gap between the joining plates; modification of the ambient conditions – local reduction of the pressure in the welding zone; modification of the welding process – preheating of the welding zone. Approaches to improve the efficiency are analyzed and compared both separately and combined. These experimentally proven methods confirm previous findings and contribute additional evidence which expand the opportunities for laser beam welding applications. The focus of this research was primarily on the effects of edge surface roughness preparation and pre-set air gap between the plates on weld quality and penetration depth. To date, there has been no reliable evidence that such modifications of the workpiece give a positive effect on the welding efficiency. Other methods were tested in combination with the two methods mentioned above. The most promising - combining with reduced pressure method - resulted in at least 100% increase in efficiency. The results of this thesis support the idea that joining those methods in one modified process will provide the modern engineering with a sufficient tool for many novel applications with potential benefits to a range of industries.

Genetics of inherited small vessel diseases – in search of a novel small vessel disease and modifiers of the clinical course of CADASIL

The genetic and environmental risk factors of vascular cognitive impairment are still largely unknown. This thesis aimed to assess the genetic background of two clinically similar familial small vessel diseases (SVD), CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy) and Swedish hMID (hereditary multi-infarct dementia of Swedish type). In the first study, selected genetic modifiers of CADASIL were studied in a homogenous Finnish CADASIL population of 134 patients, all carrying the p.Arg133Cys mutation in NOTCH3. Apolipoprotein E (APOE) genotypes, angiotensinogen (AGT) p.Met268Thr polymorphism and eight NOTCH3 polymorphisms were studied, but no associations between any particular genetic variant and first-ever stroke or migraine were seen. In the second study, smoking, statin medication and physical activity were suggested to be the most profound environmental differences among the monozygotic twins with CADASIL. Swedish hMID was for long misdiagnosed as CADASIL. In the third study, the CADASIL diagnosis in the Swedish hMID family was ruled out on the basis of genetic, radiological and pathological findings, and Swedish hMID was suggested to represent a novel SVD. In the fourth study, the gene defect of Swedish hMID was then sought using whole exome sequencing paired with a linkage analysis. The strongest candidate for the pathogenic mutation was a 3’UTR variant in the COL4A1 gene, but further studies are needed to confirm its functionality. This study provided new information about the genetic background of two inherited SVDs. Profound knowledge about the pathogenic mutations causing familial SVD is also important for correct diagnosis and treatment options.

In Search for the European solidarity: The rule of law within the European Union in the framework of constitutional pluralism

The dissertation examines the rule of law within the European Union in the theoretical framework of constitutional pluralism. The leading lines of constitutional pluralism are examined with relation to the traditional and prevailing, monistic and hierarchical conceptions on how to perceive legal orders in Europe. The theoretical part offers also historical perspective by highlighting some of the turning points for the Union constitutional legal order in the framework of European integration. The concept of rule of law is examined in legal terms and its meaning to the Union constitutional constellation as a constitutional principle and a common value is observed. The realization of the rule of law at supranational and national level is explored with a view to discover that recent developments in some of the Member States give rise to concern about the viability of the rule of law within the European Union. It is recognized that the inobservance of the rule of law at national level causes a threat to the supranational constitutional legal order. The relationship between the supranational and national legal orders is significant in this respect and therefore particularly the interaction between the Court of Justice of the European Union (hereinafter the ECJ) and the Member States’ (constitutional/supreme) courts takes focus. It is observed that functioning dialogue between the supranational and national courts based on mutual respect and judicial deference is an important prerequisite for the realization of the rule of law within Europe. In order to afford a concrete example, a recent case C-62/14 Gauweiler v Deutscher Bundestag is introduced and analysed in relation to the notorious relationship between the Federal Constitutional Court of Germany and the ECJ. The implications of the ECJ’s decision in Gauweiler v Deutscher Bundestag is assessed with reference to some of the pressing issues of constitutionalism within Europe and some institutional aspects are also brought forward. Lastly, the feasibility of constitutional pluralism as a theoretical setting is measured against the legal reality of today’s Europe and its many constitutions. The hierarchical idea of one ultimate source of power, stemming from the traditional approaches to legal systems, is then assessed with relation to the requirement of the realization of the rule of law within the European Union from the supranational and national point of view.

In search of good relationships to music : understanding aspiration and challenge in developing music school teacher practices

This study focuses on teacher practices in publicly funded music schools in Finland. As views on the aims of music education change and broaden, music schools across Europe share the challenge of developing their activities in response. In public and scholarly debate, there have been calls for increased diversity of contents and concepts of teaching. In Finland, the official national curriculum for state-funded music schools builds on the ideal that teaching and learning should create conditions which promote ‘a good relationship to music’. The meaning of this concept has been deliberately left open in order to leave room for dialogue, flexibility, and teacher autonomy. Since what is meant by ‘good’ is not defined in advance, the notion of ‘improving’ practices is also open to discussion. The purpose of the study is to examine these issues from teachers’ point of view by asking what music school teachers aim to accomplish as they develop their practices. Methodologically, the study introduces a suggestion for building empirical research on Alperson’s ‘robust’ praxial approach to music education, a philosophical theory which is strongly committed to practitioner perspectives and musical diversity. A systematic method for analysing music education practices, interpretive practice analysis, is elaborated with support from interpretive research methods originally used in policy analysis. In addition, the research design shows how reflecting conversations (a collaborative approach well-known in Nordic social work) can be fruitfully applied in interpretive research and combined with teacher inquiry. Data have been generated in a collaborative project involving five experienced music school teachers and the researcher. The empirical material includes transcripts from group conversations, data from teacher inquiry conducted within the project, and transcripts from follow-up interviews. The teachers’ aspirations can be understood as strivings to reinforce the connection between musical practices and various forms of human flourishing such that music and flourishing can sustain each other. Examples from their practices show how the word ‘good’ receives its meaning in context. Central among the teachers’ concerns is their hope that students develop a free and sustainable interest in music, often described as inspiration. I propose that ‘good relationships to music’ and ‘inspiration’ can be understood as philosophical mediators which support the transition from an indeterminate ‘interest in music’ towards specific ways in which music can become a (co-)constitutive part of living well in each person’s particular circumstances. Different musical practices emphasise different aspects of what is considered important in music and in human life. Music school teachers consciously balance between a variety of such values. They also make efforts to resist pressure which might threaten the goods they think are most important. Such goods include joy, participation, perseverance, solid musical skills related to specific practices, and a strong sense of vitality. The insights from this study suggest that when teachers are able to create inspiration, they seem to do so by performing complex work which combines musical and educational aims and makes general positive contributions to their students’ lives. Ensuring that teaching and learning in music schools remain as constructive and meaningful as possible for both students and teachers is a demanding task. The study indicates that collaborative, reflective and interdisciplinary work may be helpful as support for development processes on both individual and collective levels of music school teacher practices.

In search of the interrelatedness of innovation and internationalisation processes in entrepreneurial life science companies

This study is motivated by the question how resource scarce innovative entrepreneurial companies seek and leverage global resources. This study takes a resource-seeking perspective a step forward and suggests that resources that enable the entrepreneurial internationalisation are largely accrued from the early stages of entrepreneurial life; that is from the innovation development. Consequently, this study seeks to explain how innovation and internationalisation processes are interrelated in the entrepreneurial internationalisation. This main objective is approached through three research questions, (1) What role do inter-organisational relationships in innovation have in the entrepreneurial internationalisation process? (2) What kind of inward–outward links do inter-organisational relationships create in the resource-seeking-based entrepreneurial internationalisation process? (3) What kind of capability to collaborate forms in the interaction of inter-organisational relationship deployment? The research design is a mixed methods design that consists of quantitative pilot study and qualitative multiple case study of five entrepreneurial life science companies from Finland and Austria. The findings show that innovation and internationalisation processes are tightly interwoven in pre-internationalisation state. The findings also reveal that the more experienced companies are able to take advantage of complexcross-border inter-organisational relationship structures better than the starting companies. However, very minor evidence was found on inward links translating into outward links in the entrepreneurial internationalisation process, despite the expectation to observe more of these links in the data. Combined intangible-tangible resource-seeking was the most preferred to build links between inward–outward internationalisation but also to develop competence to collaborate. By adopting a resource- instead of market-seeking approach, this study illustrated that internationalisation extends to early stages of innovative companies, and that in high-technology companies’ potentially significant cross-border relationships have started to form long before incorporation. Therefore, these observations justified the firmer inclusion of pre-company history in innovative entrepreneurship studies. The study offers a conceptualisation of entrepreneurial internationalisation that is perceived as a process. The main theoretical contributions are in the areas of international entrepreneurship and in the behavioural process studies of entrepreneurial internationalisation and resource-based internationalisation. The inclusion of the innovation-based discussion, namely the innovation process, in the internationalisation process theories has clearly contributed to the understanding of entrepreneurial internationalisation in the context of international entrepreneurship. Innovation development is a central act of entrepreneurial companies, and neglecting innovation process investigation from entrepreneurial internationalisation leaves potentially influential mechanisms unexplored.

Content-centered method for search engine optimization

Value of online business has grown to over one trillion USD. This thesis is about search engine optimization, which focus is to increase search engine rankings. Search engine optimization is an important branch of online marketing because the first page of search engine results is generating majority of the search traffic. Current articles about search engine optimization and Google are indicating that with the proper use of quality content, there is potential to improve search engine rankings. However, the existing search engine optimization literature is not noticing content at a sufficient level. To decrease that difference, the content-centered method for search engine optimization is constructed, and content in search engine optimization is studied. This content-centered method consists of three search engine optimization tactics: 1) content, 2) keywords, and 3) links. Two propositions were used for testing these tactics in a real business environment and results are suggesting that the content-centered method is improving search engine rankings. Search engine optimization is constantly changing because Google is adjusting its search algorithm regularly. Still, some long-term trends can be recognized. Google has said that content is growing its importance as a ranking factor in the future. The content-centered method is taking advance of this new trend in search engine optimization to be relevant for years to come.

Content-centered method for search engine optimization

Value of online business has grown to over one trillion USD. This thesis is about search engine optimization, which focus is to increase search engine rankings. Search engine optimization is an important branch of online marketing because the first page of search engine results is generating majority of the search traffic. Current articles about search engine optimization and Google are indicating that with the proper use of quality content, there is potential to improve search engine rankings. However, the existing search engine optimization literature is not noticing content at a sufficient level. To decrease that difference, the content-centered method for search engine optimization is constructed, and content in search engine optimization is studied. This content-centered method consists of three search engine optimization tactics: 1) content, 2) keywords, and 3) links. Two propositions were used for testing these tactics in a real business environment and results are suggesting that the content-centered method is improving search engine rankings. Search engine optimization is constantly changing because Google is adjusting its search algorithm regularly. Still, some long-term trends can be recognized. Google has said that content is growing its importance as a ranking factor in the future. The content-centered method is taking advance of this new trend in search engine optimization to be relevant for years to come.