A Topological Approach to Fuzzy Sets

This thesis presents a topological approach to studying fuzzy setsby means of modifier operators. Modifier operators are mathematical models, e.g., for hedges, and we present briefly different approaches to studying modifier operators. We are interested in compositional modifier operators, modifiers for short, and these modifiers depend on binary relations. We show that if a modifier depends on a reflexive and transitive binary relation on U, then there exists a unique topology on U such that this modifier is the closure operator in that topology. Also, if U is finite then there exists a lattice isomorphism between the class of all reflexive and transitive relations and the class of all topologies on U. We define topological similarity relation "≈" between L-fuzzy sets in an universe U, and show that the class LU/ ≈ is isomorphic with the class of all topologies on U, if U is finite and L is suitable. We consider finite bitopological spaces as approximation spaces, and we show that lower and upper approximations can be computed by means of α-level sets also in the case of equivalence relations. This means that approximations in the sense of Rough Set Theory can be computed by means of α-level sets. Finally, we present and application to data analysis: we study an approach to detecting dependencies of attributes in data base-like systems, called information systems.

Spinor Bose-Einstein Condensates and Topological Defects

This thesis concentrates on the topological defects of spin-1 and spin-2 Bose-Einstein condensates, the ground states of spin-3 condensates, and the inert states of spinor condensates with arbitrary spin. Our work is based on the description of a spinor condensate of spin-S atoms in terms of a state vector of a spin-S particle. The results of the homotopy theory are used to study the existence and structure of the topological defects in spinor condensates. We construct examples of defects, study their energetics, and examine how their stability is affected by the presence of an external magnetic field. The ground states of spin-3 condensates are calculated using analytical and numerical means. Special emphasis is put on the ground states of a chromium condensate, whose dependence on the magnetic dipole-dipole interaction is studied. A simple geometrical method for the calculation of inert states of spinor condensates is presented. This method is used to find candidates for the ground states of spin-S condensates.

Contact Center Functionality - Collecting and Prioritizing Features of Modern Contact Center.

Tässä diplomityössä pohditaan call centereiden asemaa tämän päivän palveluympäristössä ja myöskin call centereiden tulevaisuutta contact centereinä. Tämä työ tutkii kuinka asiakastarpeita ja uusia toiminnallisuuksia voidaan etsiä olemassaolevaan, mutta vielä keskeneräiseen call center tuotteeseen. Tutkimus on tehty lukemalla artikkeleita ja kirjoja tulevaisuuden contact centereistä, haastattelemalla asiakkaita ja järjestämällä ideointisessio yrityksen asiantuntijoille. Näin saadut tulokset priorisoitiin tätä tarkoitusta varten kehitellyllä matriisilla. Lopullisena tuloksena on lista toiminnallisuuksista tärkeysjärjestyksessä ja tuote roadmap kaikkein tärkeimmistä toiminnallisuuksista. Tämä roadmap antaa tuotekehitykselle ehdotuksen mitä tulisi implementoida nykyiseen tuotteeseen ja mitkä ovat prioriteetit. Tässä työssä pohdiskellaan myös tuotteen modulaarista rakennetta.

Fuzzy subgroups, algebraic and topological points of view and complex analysis

Fuzzy subsets and fuzzy subgroups are basic concepts in fuzzy mathematics. We shall concentrate on fuzzy subgroups dealing with some of their algebraic, topological and complex analytical properties. Explorations are theoretical belonging to pure mathematics. One of our ideas is to show how widely fuzzy subgroups can be used in mathematics, which brings out the wealth of this concept. In complex analysis we focus on Möbius transformations, combining them with fuzzy subgroups in the algebraic and topological sense. We also survey MV spaces with or without a link to fuzzy subgroups. Spectral space is known in MV algebra. We are interested in its topological properties in MV-semilinear space. Later on, we shall study MV algebras in connection with Riemann surfaces. In fact, the Riemann surface as a concept belongs to complex analysis. On the other hand, Möbius transformations form a part of the theory of Riemann surfaces. In general, this work gives a good understanding how it is possible to fit together different fields of mathematics.

On Topological Solitons in The Faddeev-Skyrme Model and its Extensions

The topological solitons of two classical field theories, the Faddeev-Skyrme model and the Ginzburg-Landau model are studied numerically and analytically in this work. The aim is to gain information on the existence and properties of these topological solitons, their structure and behaviour under relaxation. First, the conditions and mechanisms leading to the possibility of topological solitons are explored from the field theoretical point of view. This leads one to consider continuous deformations of the solutions of the equations of motion. The results of algebraic topology necessary for the systematic treatment of such deformations are reviewed and methods of determining the homotopy classes of topological solitons are presented. The Faddeev-Skyrme and Ginzburg-Landau models are presented, some earlier results reviewed and the numerical methods used in this work are described. The topological solitons of the Faddeev-Skyrme model, Hopfions, are found to follow the same mechanisms of relaxation in three different domains with three different topological classifications. For two of the domains, the necessary but unusual topological classification is presented. Finite size topological solitons are not found in the Ginzburg-Landau model and a scaling argument is used to suggest that there are indeed none unless a certain modification to the model, due to R. S. Ward, is made. In that case, the Hopfions of the Faddeev-Skyrme model are seen to be present for some parameter values. A boundary in the parameter space separating the region where the Hopfions exist and the area where they do not exist is found and the behaviour of the Hopfion energy on this boundary is studied.

Equivalence and translation strategies in multilingual thesaurus construction

In the present dissertation, multilingual thesauri were approached as cultural products and the focus was twofold: On the empirical level the focus was placed on the translatability of certain British-English social science indexing terms into the Finnish language and culture at a concept, a term and an indexing term level. On the theoretical level the focus was placed on the aim of translation and on the concept of equivalence. In accordance with modern communicative and dynamic translation theories the interest was on the human dimension. The study is qualitative. In this study, equivalence was understood in a similar way to how dynamic, functional equivalence is commonly understood in translation studies. Translating was seen as a decision-making process, where a translator often has different kinds of possibilities to choose in order to fulfil the function of the translation. Accordingly, and as a starting point for the construction of the empirical part, the function of the source text was considered to be the same or similar to the function of the target text, that is, a functional thesaurus both in source and target context. Further, the study approached the challenges of multilingual thesaurus construction from the perspectives of semantics and pragmatics. In semantic analysis the focus was on what the words conventionally mean and in pragmatics on the ‘invisible’ meaning - or how we recognise what is meant even when it is not actually said (or written). Languages and ideas expressed by languages are created mainly in accordance with expressional needs of the surrounding culture and thesauri were considered to reflect several subcultures and consequently the discourses which represent them. The research material consisted of different kinds of potential discourses: dictionaries, database records, and thesauri, Finnish versus British social science researches, Finnish versus British indexers, simulated indexing tasks with five articles and Finnish versus British thesaurus constructors. In practice, the professional background of the two last mentioned groups was rather similar. It became even more clear that all the material types had their own characteristics, although naturally not entirely separate from each other. It is further noteworthy that the different types and origins of research material were not used to represent true comparison pairs, and that the aim of triangulation of methods and material was to gain a holistic view. The general research questions were: 1. Can differences be found between Finnish and British discourses regarding family roles as thesaurus terms, and if so, what kinds of differences and which are the implications for multilingual thesaurus construction? 2. What is the pragmatic indexing term equivalence? The first question studied how the same topic (family roles) was represented in different contexts and by different users, and further focused on how the possible differences were handled in multilingual thesaurus construction. The second question was based on findings of the previous one, and answered to the final question as to what kinds of factors should be considered when defining translation equivalence in multilingual thesaurus construction. The study used multiple cases and several data collection and analysis methods aiming at theoretical replication and complementarity. The empirical material and analysis consisted of focused interviews (with Finnish and British social scientists, thesaurus constructors and indexers), simulated indexing tasks with Finnish and British indexers, semantic component analysis of dictionary definitions and translations, coword analysis and datasets retrieved in databases, and discourse analysis of thesauri. As a terminological starting point a topic and case family roles was selected. The results were clear: 1) It was possible to identify different discourses. There also existed subdiscourses. For example within the group of social scientists the orientation to qualitative versus quantitative research had an impact on the way they reacted to the studied words and discourses, and indexers placed more emphasis on the information seekers whereas thesaurus constructors approached the construction problems from a more material based solution. The differences between the different specialist groups i.e. the social scientists, the indexers and the thesaurus constructors were often greater than between the different geo-cultural groups i.e. Finnish versus British. The differences occurred as a result of different translation aims, diverging expectations for multilingual thesauri and variety of practices. For multilingual thesaurus construction this means severe challenges. The clearly ambiguous concept of multilingual thesaurus as well as different construction and translation strategies should be considered more precisely in order to shed light on focus and equivalence types, which are clearly not self-evident. The research also revealed the close connection between the aims of multilingual thesauri and the pragmatic indexing term equivalence. 2) The pragmatic indexing term equivalence is very much context-depended. Although thesaurus term equivalence is defined and standardised in the field of library and information science (LIS), it is not understood in one established way and the current LIS tools are inadequate to provide enough analytical tools for both constructing and studying different kinds of multilingual thesauri as well as their indexing term equivalence. The tools provided in translation science were more practical and theoretical, and especially the division of different meanings of a word provided a useful tool in analysing the pragmatic equivalence, which often differs from the ideal model represented in thesaurus construction literature. The study thus showed that the variety of different discourses should be acknowledged, there is a need for operationalisation of new types of multilingual thesauri, and the factors influencing pragmatic indexing term equivalence should be discussed more precisely than is traditionally done.

A contact-linguistic view on Finland-Swedish quotatives vara ’be’ and att ’that’

Artikel i konferensrapport.

CFD Modelling of Direct Contact Condensation in Suppression Pools by Applying Condensation Models of Separated Flow

The condensation rate has to be high in the safety pressure suppression pool systems of Boiling Water Reactors (BWR) in order to fulfill their safety function. The phenomena due to such a high direct contact condensation (DCC) rate turn out to be very challenging to be analysed either with experiments or numerical simulations. In this thesis, the suppression pool experiments carried out in the POOLEX facility of Lappeenranta University of Technology were simulated. Two different condensation modes were modelled by using the 2-phase CFD codes NEPTUNE CFD and TransAT. The DCC models applied were the typical ones to be used for separated flows in channels, and their applicability to the rapidly condensing flow in the condensation pool context had not been tested earlier. A low Reynolds number case was the first to be simulated. The POOLEX experiment STB-31 was operated near the conditions between the ’quasi-steady oscillatory interface condensation’ mode and the ’condensation within the blowdown pipe’ mode. The condensation models of Lakehal et al. and Coste & Lavi´eville predicted the condensation rate quite accurately, while the other tested ones overestimated it. It was possible to get the direct phase change solution to settle near to the measured values, but a very high resolution of calculation grid was needed. Secondly, a high Reynolds number case corresponding to the ’chugging’ mode was simulated. The POOLEX experiment STB-28 was chosen, because various standard and highspeed video samples of bubbles were recorded during it. In order to extract numerical information from the video material, a pattern recognition procedure was programmed. The bubble size distributions and the frequencies of chugging were calculated with this procedure. With the statistical data of the bubble sizes and temporal data of the bubble/jet appearance, it was possible to compare the condensation rates between the experiment and the CFD simulations. In the chugging simulations, a spherically curvilinear calculation grid at the blowdown pipe exit improved the convergence and decreased the required cell count. The compressible flow solver with complete steam-tables was beneficial for the numerical success of the simulations. The Hughes-Duffey model and, to some extent, the Coste & Lavi´eville model produced realistic chugging behavior. The initial level of the steam/water interface was an important factor to determine the initiation of the chugging. If the interface was initialized with a water level high enough inside the blowdown pipe, the vigorous penetration of a water plug into the pool created a turbulent wake which invoked the chugging that was self-sustaining. A 3D simulation with a suitable DCC model produced qualitatively very realistic shapes of the chugging bubbles and jets. The comparative FFT analysis of the bubble size data and the pool bottom pressure data gave useful information to distinguish the eigenmodes of chugging, bubbling, and pool structure oscillations.

Ambidextrous leadership in customer contact centre organization

In a modern dynamic environment organizations are facing new requirements for success and competitive advantage. This also sets new requirements for leaders. The term of ambidexterity is used in relation with organizations that are able to manage short-term efficiency and long-term innovation simultaneously. Ambidextrous leaders have the same capability at an individual level. They are able to balance between efficiency and flexibility. This study examined the confrontation of these two competing concepts in the leadership perspective. The aim of the study was to understand this recently arisen concept and its antecedents and examine what is currently known about ambidextrous leadership. This was a case study with data collected through theme interviews in a result orientated customer centre organization that has a cultural change at hand when it comes to leadership and empowerment. Organization wants to be efficient and flexible at the same time (a.k.a. ambidextrous) and that requires new type of leadership. In this study the aim was to describe the capabilities and criteria for ambidextrous leader and examine the leadership roles related to ambidextrous leadership in different hierarchical levels. The case organization had also created systematic means to support this cultural change and the effects of the process related to leadership were studied. This study showed that the area is yet widely unexplored and contradictory views are presented. This study contributes to the deprivation of study of ambidexterity in leadership and individuals. The study presents a description of ambidextrous leadership and describes the capabilities of ambidextrous leader. Ambidextrous leaders are able to make cognitive decisions between their leadership style according to situation that requires either leadership related to efficiency such as transactional leadership or leadership related to flexibility such as transformational leadership. Their leadership style supports both short-term and long-term goals. This study also shows that the role of top management is vital and operational leaders rely on their example.

Side peaks in Nb and NbTi point-contact spectra

Superconductor – normal metal point contacts were investigated, using different combinations of Cu, brass, Nb and NbTi. The resulting spectra contained side peaks. The currents at which these side peaks appeared, depended on the radii of the contacts. For contacts with Nb this dependence was quadratic, while for contacts with NbTi it was linear. Based on this, we argue that the side peaks in the case of the Nb contacts are due to the critical current density being exceeded. In contrast, side peaks of the NbTi contacts are caused by the self-magnetic field exceeding the lower critical field of NbTi. The NbTi contacts did not show the expected contribution from the vanishing Maxwell resistance of the superconductor, a question which remained open.

A Soft Contact Collision Method For Real-Time Simulation of Triangularized Geometries in Multibody Dynamics

When modeling machines in their natural working environment collisions become a very important feature in terms of simulation accuracy. By expanding the simulation to include the operation environment, the need for a general collision model that is able to handle a wide variety of cases has become central in the development of simulation environments. With the addition of the operating environment the challenges for the collision modeling method also change. More simultaneous contacts with more objects occur in more complicated situations. This means that the real-time requirement becomes more difficult to meet. Common problems in current collision modeling methods include for example dependency on the geometry shape or mesh density, calculation need increasing exponentially in respect to the number of contacts, the lack of a proper friction model and failures due to certain configurations like closed kinematic loops. All these problems mean that the current modeling methods will fail in certain situations. A method that would not fail in any situation is not very realistic but improvements can be made over the current methods.