CFD simulation of complex phenomena containing suspensions and flow throughporous media

There is an increasing reliance on computers to solve complex engineering problems. This is because computers, in addition to supporting the development and implementation of adequate and clear models, can especially minimize the financial support required. The ability of computers to perform complex calculations at high speed has enabled the creation of highly complex systems to model real-world phenomena. The complexity of the fluid dynamics problem makes it difficult or impossible to solve equations of an object in a flow exactly. Approximate solutions can be obtained by construction and measurement of prototypes placed in a flow, or by use of a numerical simulation. Since usage of prototypes can be prohibitively time-consuming and expensive, many have turned to simulations to provide insight during the engineering process. In this case the simulation setup and parameters can be altered much more easily than one could with a real-world experiment. The objective of this research work is to develop numerical models for different suspensions (fiber suspensions, blood flow through microvessels and branching geometries, and magnetic fluids), and also fluid flow through porous media. The models will have merit as a scientific tool and will also have practical application in industries. Most of the numerical simulations were done by the commercial software, Fluent, and user defined functions were added to apply a multiscale method and magnetic field. The results from simulation of fiber suspension can elucidate the physics behind the break up of a fiber floc, opening the possibility for developing a meaningful numerical model of the fiber flow. The simulation of blood movement from an arteriole through a venule via a capillary showed that the model based on VOF can successfully predict the deformation and flow of RBCs in an arteriole. Furthermore, the result corresponds to the experimental observation illustrates that the RBC is deformed during the movement. The concluding remarks presented, provide a correct methodology and a mathematical and numerical framework for the simulation of blood flows in branching. Analysis of ferrofluids simulations indicate that the magnetic Soret effect can be even higher than the conventional one and its strength depends on the strength of magnetic field, confirmed experimentally by Völker and Odenbach. It was also shown that when a magnetic field is perpendicular to the temperature gradient, there will be additional increase in the heat transfer compared to the cases where the magnetic field is parallel to the temperature gradient. In addition, the statistical evaluation (Taguchi technique) on magnetic fluids showed that the temperature and initial concentration of the magnetic phase exert the maximum and minimum contribution to the thermodiffusion, respectively. In the simulation of flow through porous media, dimensionless pressure drop was studied at different Reynolds numbers, based on pore permeability and interstitial fluid velocity. The obtained results agreed well with the correlation of Macdonald et al. (1979) for the range of actual flow Reynolds studied. Furthermore, calculated results for the dispersion coefficients in the cylinder geometry were found to be in agreement with those of Seymour and Callaghan.

Improving the effectiveness of supply chain development work – an expert role perspective

This study focuses to the intersection of three sets of activities in a company: expert work, development work and supply chain management, SCM. Experts and expert work represent a set of individuals whose efficiency and impact this study is intended to improve, while development work defines the set of organizational activities to focus on. SCM as an expertise area acts as the platform on which this study is built. The study has two aims. Firstly, it aims to derive a model helping an SCM expert to increase the effectiveness of expert work in development tasks by understanding the encountered organizational situations and processes better, reflecting his/her past and future actions to organizational processes and selecting and adjusting the processes and contents of his/her work accordingly. Secondly, it aims to develop applicable approaches and methods to understand, evaluate and manage the organizational processes and situations in development work. The integrative model on approaches and methods to improve the effectiveness of development processes is split to two aggregate dimensions: technical performance of the developed solution and consumption of resources of the development process. Six potential approaches and methods aiming at helping in the management of organizational dimensions are presented in enclosed publications. The approaches focus on three subtasks of development work: decision making, implementation and change, and knowledge accumulation. The approaches and methods have been tested in case studies representing typical development processes in the area of supply chain management. As a result, four suggestions are presented. Firstly, SCM experts are advised to consider the SCM development work to be consisting of development processes. Secondly, inside these processes they should identify and evaluate the risk of difficult decision-making related to organizational factors. Thirdly, they are prompted for an active role in implementation and change, supporting the implementation through whole process. Finally, the development should be seen in a holistic view, taking into account the stage of knowledge and organizational issues related to it, and adopt a knowledge development strategy.

Akateemiset urapolut. Humanistisen, yhteiskuntatieteellisen ja kasvatustieteellisen alan generalistien urapolkujen alkuvaiheet 1980- ja 1990-luvuilla

Academic Career Paths. The early career phases of generalists in the fields of humanities, social science and education in the 1980’s and 1990’s This doctoral thesis analyses how generalist graduates of master’s degree have attached to the labour market in two different time periods, and how their career paths in the first eight years following graduation have shaped up. The thesis also analyses the channels of employment through which the generalists have got employed in their early career path. By generalists I am referring to graduates of studies in academic fields which have not qualified the person in a specific profession but rather offered a more general readiness for working life. I address two groups of generalist master’s degree graduates of The University of Turku; one including graduates of the year 1985 and the other consisting of graduates of 1995. All subjects have graduated in the field of humanities, social studies or education. 71 respondents from the group of 1985 and 80 respondents from the group of 1995 answered a survey, which provided the data for the thesis. I interpret the data through the theoretical approaches of changing working life, model of normal employment, transitional labour markets, linear life path, overlapping life courses, hidden labour market and social capital. The conclusion of the thesis is that societal era is connected with employment and career paths of academic generalists. Between the two groups there were differences especially in attachment to labor market, in forms of employment (permanent full-time job vs. temporary job) and in employment channels. Compared to the situation the 1985 group had been in after their graduation, the 1995 group - after getting their degree - became more often unemployed and/or employed in duties below their level of education. Their mobility was also greater and their contracts were often temporary, whereas the graduates of 1985 had been employed in more permanent positions. I demonstrate that the career paths of generalists can be categorized in five career types: steady state, transitory, linear, unsteady and diverging career. Graduates of 1985 have been treading on more stable paths than the latter group. The channels of employment they used were roughly equally divided between formal (e.g. newspaper advertisement and employment office) and informal (e.g. personal contacts and unprompted search for work) channels, whereas amongst the 1995 group employment happened through more varied channels and mostly through informal channels. Regardless of their year of graduation the generalists’ careers had begun to evolve already while they were still in the university and had started working at the same time. The thesis displays how the model of normal employment has weakened and career paths have become unsteady as a consequence of temporary positions. What is also evident in employment when turning from the 1980’s towards the succeeding decade is the rise of significance of the hidden labour market and social capital.

Making Sense of Women Managers’ Identities through the Constructions of Managerial Career and Gender

This doctoral thesis is about gendered managerial identity construction of women managers. Finnish women managers have been researched from the viewpoints of equality and discrimination issues, careers, and women’s overall positions in work life. However, managerial identity has remained as an unexplored territory. The phenomenon is approached discourse analytically; an interview material that is gathered from 13 women managers in the South-Karelian region is in focus. By studying discourses it is possible to open up understandings how meanings are given to experiences. Women managers’ identity construction is examined from the perspectives of managerial career, managerial practices, and gender. Gender is a meta-concept in this research, as it so profoundly affects our sense of being and acting, although the meaning of it often remains undervalued, invisible, or even denied. This research shows that gender becomes highly visible in managerial contexts, when it is used for some specific purpose, that is, treated as a strategy. By studying women managers it is possible to demystify often so abstract managerial ideals, and open up their taken-for-granted masculine subtexts. It is argued that from the point of view of conducting managerial work, the meaning of self-knowledge appears as critical.

Maahanmuuttajaoppilaan osallisuus koulukiusaamisessa

Maahanmuuttajataustaisten oppilaiden määrä Suomen peruskouluissa on lisääntynyt voimistuen 1990-luvulta lähtien, ja tämä kehitys on jatkunut näihin päiviin saakka. Väestöennusteissa ennakoidaan yleisesti maahanmuuton kehittyvän lähivuosikymmeninä maastamuuttoa voimakkaammin. Valtakunnantason tavoitteena on, että maahanmuuttajat täyttävät sen työvoimavajeen, joka syntyy ikääntyvän suomalaisväestön siirtymisestä eläkkeelle. Tähän astiselle muutolle on ollut ominaista, että se tapahtuu perheittäin. Tästä johtuen perheiden kouluikäiset lapset aloittavat koulunkäyntinsä tai jatkavat koulunkäyntiään täällä. Samalla he saavat ensikosketuksensa suomalaisissa kouluissa tapahtuvaan koulukiusaamiseen. Tämän tutkimuksen tarkoituksena oli selvittää maahanmuuttajaoppilaan osallisuutta koulukiusaamisessa. Teoriaosuudessa tarkasteltavana on toisaalta maahanmuuttajaoppilas ja toisaalta koulukiusaamisilmiö. Empiriaosuus pyrkii selvittämään, minkälaisia yhteyksiä näillä kahdella asialla on keskenään. Tutkimukseen osallistui kuuden turkulaisen alakoulun kaikki kolmas ja viidesluokkalaiset oppilaat (N=633) yhteensä 26 koululuokasta. Otos muodostui 526 suomalaisesta ja 107 maahanmuuttajataustaisesta oppilaasta. Aineisto kerättiin survey-tutkimukselle tyypilliseen tapaan kyselylomaketta käyttäen. Koulukiusaaminen on oppilaiden käsityksistä muodostettujen tulosten perusteella monikulttuurisissa kouluissa varsin yleinen ilmiö. Noin joka neljäs kaikista tutkimukseen osallistuneista oppilaista kiusasi muita oppilaita usein. Uhriksi itsensä kokevien määrä oli tätäkin suurempi. Kiusaajana tai uhrina oli useammin maahanmuuttaja kuin suomalainen oppilas. Monikulttuurisissa kouluissa koulukiusaamista ei tapahtunut vain valtaenemmistöön tai etniseen vähemmistöön kuuluvien välillä, vaan myös yli etnisten vähemmistörajojen tai saman vähemmistön sisällä. Kolmasosa maahanmuuttajista uskoi itsekin maahanmuuttajan kiusaavan pikemmin toista maahanmuuttajaa kuin suomalaista oppilasta. Kiusaamisilmiö liittyy erityisesti maahanmuuttajapoikiin. Heistä puolet ilmoitettiin nimeltä kiusaajiksi tai kiusaamisen uhreik-si. Suomalaisista pojista kolmasosa nimettiin kiusaajaksi tai uhriksi. Maahanmuuttajatytöistä joka viides kiusasi ja joka kolmatta kiusattiin. Suomalaisista tytöistä joka kymmenes oli kiusaaja ja joka viides oli kiusaamisen uhrin asemassa. Vaikka koulukiusaamista tapahtuu, siitä vaietaan sekä kotona että koulussa. Aikuisille kiusaamisesta ei haluta kertoa. Maahanmuuttajaoppilas kertoo itseensä kohdistuneesta kiusaamisesta suomalaista useammin opettajalleen kuin vanhemmilleen. Suomalainen oppilas luottaa vanhempiinsa opettajaa enemmän. Tulosten perusteella näyttää kiusaamista tapahtuvan erityisen paljon välituntien aikana. Suomalaiset ja maahanmuuttajaoppilaat olivat yksimielisiä välituntiin liittyvästä uhkatekijöistä ja siitä, että samat kiusaajat toistuvasti suorittavat ryhmänä väkivaltaisia tekojaan. Joka neljäs maahanmuuttajaoppilas ja joka seitsemäs suomalainen pelkää joutuvansa kiusatuksi välitunnilla.

Työhyvinvointi, koulutus ja toiminnan kehittäminen terveyskeskuksissa lääkäritilanteen näkökulmasta

Finnish health centres have suffered from a shortage of physicians in recent years. This is why more physicians are being educated, the tutelage of the young physicians has been improved and many tasks which were previously reserved for physicians have been transferred to nurses and other personnel of the health centres. Only a little research has been done about the effects of the shortage of physicians and education to the work atmosphere in the health centres The objectives of the study was to describe the situation of the physicians in the counties Satakunta and South-Western Finland at the time when the University of Turku started to decentralise its education to Satakunta and describe the health centres attitudes towards training and research co-operation with the University of Turku; to gain information about the training programmes for physicians in specific training in general medical practice (STPG); study how the shortage of physicians affects the job atmosphere, the job satisfaction and the operation of the health centres; study health centre employees opinions about their professional skills, their needs and interets in continuing education; study medical and nurse students professional indentity and their readiness to multiprofessional teamwork. The material of the study was gathered during 2003-2006 with three mail questionnaires and a questionnaire given to medical and nurse students who practised in the training health centre in Pori. The first questionnaire was sent to the chief physicians of the health centres in counties Satakunta and South-Western Finland to clarify the number of unfilled positions of physicians and the reasons for physician shortage as well as the readiness for practical training of medical students and research at the health centres. The second questionnaire was posted to doctors in specific training in general medical practice and their trainers at the health centres and it gained information about training programmes of young physicians at health centres. The third questionnaire was sent to personnel at health centres in Satakunta and South-Western Finland and included questions about job satisfaction and education. The survey for medical and nurse students gained information about their professional indentity and their readiness to multiprofessional teamwork. In spring 2003 the shortage of physicians was more severe in Satakunta than in South-Western Finland. Attitudes towards training of medical students and research co-operation with the universities were generally positive. The guidance of STGP doctors in health centres improved during 2003-2005. A shortage of physicians had only a slightly negative impact on employee job satisfaction. The shortage of physicians had also positive impact on the operation of the health centres because it led to reorganization of the operations. The personnel at Finnish health centres were willing to take more challenging tasks and also to acquire appropriate further education or training. The medical and nurse students had strong professional identity and they understood the significance of teamwork for the health care service system.

Osaamisen johtaminen Suomen kunnissa

Kunnissa eletään muutosten aikaa, ja osaamisen johtamisella pyritään vastaamaan kehityksen mukanaan tuomiin haasteisiin. Osaamisen johtamista pidetäänkin tärkeänä asiana kuntien kehittämisessä. Viime vuosina osaamisen johtaminen on ollut voimakkaasti esillä myös yksityisellä sektorilla, jossa se on nähty tärkeänä elementtinä kilpailukyvyn kehittämisessä. Osaamisen johtaminen on toimintaa, jolla kehitetään yksilöiden ja organisaation osaamista sekä organisaation yhteistyövalmiutta. Osaamisen johtamisessa huomioidaan myös organisaatiolle asetetut strategiset tavoitteet. Tässä tutkimuksessa osaamisen johtaminen ankkuroidaan tietojohtamisen, henkilöstövoimavarojen johtamisen (HRM:n) ja oppivan organisaation viitekehyksiin. Tutkimusotteeksi on valittu kvantitatiivinen tutkimusote. Kvantitatiivinen tutkimusote mahdollistaa osaamisen johtamisen rakenteellisen analyysin ja kuvaamisen. Tutkimuksen kohderyhmänä ovat kaikki Suomen 444 kuntaa vuonna 2004. Tutkimuksen tiedonkeruu suoritettiin lomakekyselyn avulla, ja tutkimus kohdistettiin kuntien henkilöstöasioiden asiantuntijoille. Tutkimuksen keskeisenä tavoitteena oli mallintaa ja kuvata osaamisen johtamista Suomen kunnissa. Tutkimusongelma liittyy kuntien osaamisen johtamisen nykytilaan ja tavoitteisiin sekä siihen, missä vaiheissa kunnat ovat osaamisen johtamisessaan. Kyselyn avulla tutkittiin myös kuntien halukkuutta kehittää osaamisen johtamistaan. Vastausten pohjalta analysoitiin lisäksi, mitkä asiat kunnissa vaikuttavat osaamisen johtamiseen. Tutkimuksen tuloksissa tulevat esille neljä erilaista kunnissa vallitsevaa osaamisen johtamisen orientaatiota: Strategiaohjattu yhteisöllinen orientaatio, Innovatiivinen orientaatio, Teknologinen orientaatio ja Strategialähtöinen järjestelmäorientaatio. Nämä neljä orientaatiota ovat tunnistettavissa myös taustakirjallisuudessa. Kunnat ryhmiteltiin orientaatioiden perusteella neljään ryhmään, jotka nimettiin seuraavasti: Innostuneet aloittelijat, Tekniset aloittelijat, Edistyneet ja Kehittyvät. Innostuneiden aloittelijoiden ryhmässä korostuu innovatiivinen orientaatio, mutta muut osaamisen johtamisen orientaatiot tulevat esille heikosti. Teknisten aloittelijoiden ryhmässä korostuu teknologinen orientaatio, mutta muut osaamisen johtamisen orientaatiot tulevat esille heikosti. Edistyneiden ryhmässä kaikki osaamisen johtamisen orientaatiot tulevat hyvin esille. Kehittyvien ryhmässä korostuvat sekä innovatiivinen että teknologinen orientaatio. Kuntien osaamisen johtamisen nykytilanne on murroksessa. Osaamisen johtaminen on suuressa osassa kunnista hyvässä vauhdissa, mutta kehitettävääkin on. Tietotekniset välineet osaamisen johtamisessa ovat hyvät useimmissa kunnissa. Tulevaisuuden osaamistarpeina pidetään erityisesti vuorovaikutustaitoja ja oman ammattialan osaamista. Kunnissa on myös huomioitu ainakin tavoitteiden tasolla tulevaisuus ja sen tuomat haasteet.

Ajopuusta asiantuntijaksi – luottamushenkilöarvioinnin merkitys kunnan johtamisessa ja päätöksenteossa

Tässä johtaminen ja organisaatiot –oppialaan kuuluvassa väitöstutkimuksessa selvitetään luottamushenkilöarvioinnin merkitystä kunnan johtamisessa ja päätöksenteossa. Tutkimuksessa kuvataan luottamushenkilöiden tekemää kunnan talouden ja hallinnon arviointia ja sen merkitystä kunnan johtamisen ja päätöksenteon palautemekanismina. Empiirisen haastatteluaineiston avulla kuvataan eteläkarjalaisten tarkastuslautakuntien toimintaa ja niiden puheenjohtajina toimineiden henkilöiden kokemuksia tarkastuslautakuntien olemassaolon kahdella ensimmäisellä valtuustokaudella 1997–2000 ja 2001–2004. Tutkimus kohdistuu julkiselle sektorille, kuntien poliittis-hallinnolliseen päätöksentekoon. Tarkastuslautakuntien synnyn taustalla ymmärretään vaikuttavan yleisenä viitekehyksenä erityisesti New Public Managementin (NPM) eli uuden julkisjohtamisen ilmaisemat ajatukset mm. toimintojen tehokkuudesta, tuloksellisuudesta ja vaikuttavuudesta sekä arvioinnista osana päätöksentekoa. Tutkimuksessa hyödynnetään kehysteoriana uuden julkisjohtamisen doktriinia ja substanssiteoriana arviointiin ja arviointitutkimukseen liittyvää teoreettista tietovarantoa. Tutkimuksen ensisijainen empiirinen aineisto koostuu 16 tarkastuslautakunnan puheenjohtajan haastattelusta, jotka on analysoitu sisällönanalyysiä käyttäen. Tausta-aineistona on käytetty 112 tarkastuslautakuntien arviointikertomusta. Tutkimus on ensimmäinen väitöskirjatasoinen työ tältä aihealueelta. Työn keskeinen kontribuutio on tutkimuksessa esitettävä näkemys luottamushenkilöarvioinnista ja sen merkityksestä kunnan johtamisessa arviointitutkimuksen, uuden julkisjohtamisen ja tarkastuslautakunnista tähän mennessä tehtyjen tutkimusten sekä empiirisen haastattelututkimuksen pohjalta. Luottamushenkilöarvioinnin painopisteen nähdään siirtyneen tarkastuslautakunnan lainmukaisen tehtävänannon eli valtuuston asettamien taloudellisten ja toiminnallisten tavoitteiden toteutumisen arvioinnista kunnan toiminnan kehittämiseen, jolloin sillä on konkreettisemmin päätöksentekoa tukeva merkitys. Taaksepäin suuntautunutta arviointia ei koeta kovinkaan merkitykselliseksi, vaikka virheistä oppimisen näkökulmasta ja päätöksenteon palautemekanismina myös ex post –arviointi on tärkeää. Tutkimuksessa on sovellettu poikkitieteellistä lähestymistapaa organisaatiotutkimuksen ja uuden julkisjohtamisen, arviointitutkimuksen sekä kuntatutkimuksen näkökulmia yhteen sovittamalla. Tutkimuksessa esitetään väite, että tarkastuslautakuntia kahlitsee niiden voimakas yhteys ja perustuminen tilintarkastukseen. Tarkastuslautakuntien arviointi ei ole kehittynyt omaehtoisesti ja luottamushenkilöarvioinnin merkitys on vielä osin tunnistamatta eritoten johtamisen itsensä arvioinnin näkökulmasta.

Elämänlaatu ja iäkkäiden kaatumisten ehkäisy

Quality of life and fall prevention among the aged Improvement of quality of life is considered to be one of the most important goals of prevention, treatment and rehabilitation among the aged. The study aimed to describe and assess fall prevention interventions as a quality of life indicator, and to describe the social dimension of health-related quality of life among the aged. In addition, it aimed to assess the effects of fall prevention intervention on quality of life among the aged. The study was implemented by using a methodological triangulation. The data in the systematic review was retrieved from the databasis of medical and nursing sciences. Home-dwelling aged (n=19) participated in the qualitative study of a social dimension of quality of life. The data was gathered by the thematic interview method. The quantitative multifactorial fall prevention study comprised 591 participants, either the aged living at home or in sheltered housing, showing an increased risk of falling. Participants were randomized into an intervention or a control group. Follow-up measurements were carried out after a 12 month intervention. The data was collected by the 15D quality of life instrument and a structured questionnaire. Based on the systematic review, only in a few studies fall prevention produced positive effects on dimensions of quality of life (physical function, social function, vitality, mental health, environmental domain). Based on the thematic interview the social dimension of quality of life consisted of three themes: personal values, personal milieu and personal daily life. Based on the fall prevention program, depressive symptoms and distress decreased, managing in usual activities improved, sexual activity and phone contacts increased among men. In women, managing in usual activities improved, socializing increased and discomfort and symptoms decreased. Within the groups, self-perceived health improved among women in the intervention group and among men in the control groups. In addition, fear of falling and feelings of insecurity reduced among women in the intervention group. Personal daily life with its activities opened up new perspectives into the social dimension of good quality of life, which was emphasized especially in the interviews of the oldest participants. Multifactorial fall prevention can affect positively some physical and psychosocial dimensions of quality of life among the community-dwelling aged. Additional studies with larger sample sizes, longer follow-up periods and multiple outcome measures are needed. Fall prevention intervention may affect quality of life by different mechanisms, and the quantitative and qualitative assessment of its effects should also be included in the interventions of randomized controlled trials.

Nuorten koherenssin tunne: mittaaminen, ennustavat tekijät, seuraukset

Sense of coherence in adolescence: measuring, predictive factors, consequences The aim of this study was to explore the stability of sense of coherence (SOC) in adolescence and the associations between childhood psychological symptoms and SOC in adolescence. Furthermore, the aim of this study was to explore whether the 13-item SOC scale for adults is applicable to adolescents 12 years of age and to determine which factors are associated with perceived health and SOC. Data relating to SOC and factors associated with perceived health and SOC were collected in class in a cross-sectional setting by self-administered questionnaires in all publicly funded elementary schools (N=35) of Turku. A total of 1 231 (83%) of 1 481 12-year-old schoolchildren participated in the study. The data was, with appropriated authority consent, anonymously completed with marks in mathematics, native and first foreign language at the end of sixth class. The examination of stability of SOC in adolescence and the associations between childhood psychological symptoms and SOC was based on data of a prospective population-based mail survey. The source population originated in 11 health authority areas of the Province of Turku and Pori. The study was carried out by using questionnaires at child’s ages of 3, 12, 15, and 18 years. Acceptably completed questionnaires were returned by 1 086 (84%) parents at the child’s age of 3, at the age of 12 by 70% adolescents and parents, at the age of 15, by 66% adolescents and 58% parents, and at the age of 18, by 61.5% adolescents and 61% parents. The results of the study showed that childhood behavioural problems from the age of 3 years predicted poor SOC at the age of 18 years. A poor SOC was associated with psychological symptoms and behavioural problems in adolescence. Contrary to assumptions in Antonovsky’s theory, there was no significant change in SOC between the ages of 15 to 18 years, and the stability of SOC did not depend on initial SOC. Slight fluctuation in SOC scores was seen at the individual level. When studied cross-sectionally, in 12-year-old schoolchildren, insufficient physical exercise, less than excellent marks in mathematics, weak SOC, insufficient social support from teachers, and perceived various problems in class climate associated with perception of poor health. Identification of behavioural problems in early childhood helps to identify the children at risk of ill-being and poor SOC in adolescence since problems seem to persist unchanged until adolescence. The 13-item SOC scale aimed at adults is applicable to adolescents of 12 years of age or older and the SOC scale is a useful tool in identifying adolescents in need of supportive interventions.

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.

New Distance Transforms for Gray Level Image Compression

This thesis deals with distance transforms which are a fundamental issue in image processing and computer vision. In this thesis, two new distance transforms for gray level images are presented. As a new application for distance transforms, they are applied to gray level image compression. The new distance transforms are both new extensions of the well known distance transform algorithm developed by Rosenfeld, Pfaltz and Lay. With some modification their algorithm which calculates a distance transform on binary images with a chosen kernel has been made to calculate a chessboard like distance transform with integer numbers (DTOCS) and a real value distance transform (EDTOCS) on gray level images. Both distance transforms, the DTOCS and EDTOCS, require only two passes over the graylevel image and are extremely simple to implement. Only two image buffers are needed: The original gray level image and the binary image which defines the region(s) of calculation. No other image buffers are needed even if more than one iteration round is performed. For large neighborhoods and complicated images the two pass distance algorithm has to be applied to the image more than once, typically 3 10 times. Different types of kernels can be adopted. It is important to notice that no other existing transform calculates the same kind of distance map as the DTOCS. All the other gray weighted distance function, GRAYMAT etc. algorithms find the minimum path joining two points by the smallest sum of gray levels or weighting the distance values directly by the gray levels in some manner. The DTOCS does not weight them that way. The DTOCS gives a weighted version of the chessboard distance map. The weights are not constant, but gray value differences of the original image. The difference between the DTOCS map and other distance transforms for gray level images is shown. The difference between the DTOCS and EDTOCS is that the EDTOCS calculates these gray level differences in a different way. It propagates local Euclidean distances inside a kernel. Analytical derivations of some results concerning the DTOCS and the EDTOCS are presented. Commonly distance transforms are used for feature extraction in pattern recognition and learning. Their use in image compression is very rare. This thesis introduces a new application area for distance transforms. Three new image compression algorithms based on the DTOCS and one based on the EDTOCS are presented. Control points, i.e. points that are considered fundamental for the reconstruction of the image, are selected from the gray level image using the DTOCS and the EDTOCS. The first group of methods select the maximas of the distance image to new control points and the second group of methods compare the DTOCS distance to binary image chessboard distance. The effect of applying threshold masks of different sizes along the threshold boundaries is studied. The time complexity of the compression algorithms is analyzed both analytically and experimentally. It is shown that the time complexity of the algorithms is independent of the number of control points, i.e. the compression ratio. Also a new morphological image decompression scheme is presented, the 8 kernels' method. Several decompressed images are presented. The best results are obtained using the Delaunay triangulation. The obtained image quality equals that of the DCT images with a 4 x 4

Development a distributed simulation environment on a cluster of workstations

Simulation has traditionally been used for analyzing the behavior of complex real world problems. Even though only some features of the problems are considered, simulation time tends to become quite high even for common simulation problems. Parallel and distributed simulation is a viable technique for accelerating the simulations. The success of parallel simulation depends heavily on the combination of the simulation application, algorithm and message population in the simulation is sufficient, no additional delay is caused by this environment. In this thesis a conservative, parallel simulation algorithm is applied to the simulation of a cellular network application in a distributed workstation environment. This thesis presents a distributed simulation environment, Diworse, which is based on the use of networked workstations. The distributed environment is considered especially hard for conservative simulation algorithms due to the high cost of communication. In this thesis, however, the distributed environment is shown to be a viable alternative if the amount of communication is kept reasonable. Novel ideas of multiple message simulation and channel reduction enable efficient use of this environment for the simulation of a cellular network application. The distribution of the simulation is based on a modification of the well known Chandy-Misra deadlock avoidance algorithm with null messages. The basic Chandy Misra algorithm is modified by using the null message cancellation and multiple message simulation techniques. The modifications reduce the amount of null messages and the time required for their execution, thus reducing the simulation time required. The null message cancellation technique reduces the processing time of null messages as the arriving null message cancels other non processed null messages. The multiple message simulation forms groups of messages as it simulates several messages before it releases the new created messages. If the message population in the simulation is suffiecient, no additional delay is caused by this operation A new technique for considering the simulation application is also presented. The performance is improved by establishing a neighborhood for the simulation elements. The neighborhood concept is based on a channel reduction technique, where the properties of the application exclusively determine which connections are necessary when a certain accuracy for simulation results is required. Distributed simulation is also analyzed in order to find out the effect of the different elements in the implemented simulation environment. This analysis is performed by using critical path analysis. Critical path analysis allows determination of a lower bound for the simulation time. In this thesis critical times are computed for sequential and parallel traces. The analysis based on sequential traces reveals the parallel properties of the application whereas the analysis based on parallel traces reveals the properties of the environment and the distribution.

Improving the Potentials of Logistics Processes: Identification and Solutions

The importance of logistics for companies is a well known and justified issue. Today, enterprises are developing their logistics processes in order to match their products and services to the requirements of the most important customers. Therefore there is a need for developing analysing tools for logistics and especially for analysing the significance of various customer service elements. The aim of this paper is to propose analytic tools for supporting strategic level logistics decision making by emphasizing service level elements on two levels: (1) to introduce and propose approaches to categorize the developing efforts of logistics and (2) to introduce and/or propose approaches for solving some customer service related strategic level logistics problems. This study consists of two parts. In the first part an overview of the work is presented, and the second part comprises eight research papers on the topic of the study. The overview includes an introduction, where strategic and tactical level logistics problems are discussed and the relation of logistics to marketing and customer service issues is presented. In the first part of the study the objectives, the structure, the research strategy and the contribution of the research are described, and the challenges for future research are discussed. In the second part the three first papers deal with the identification of objectives for logistics while the remaining five papaers concentrate on solving customer service related strategic level logistics problems.