On Commutation and Conjugacy of Rational Languages and the Fixed Point Method

The research on language equations has been active during last decades. Compared to the equations on words the equations on languages are much more difficult to solve. Even very simple equations that are easy to solve for words can be very hard for languages. In this thesis we study two of such equations, namely commutation and conjugacy equations. We study these equations on some limited special cases and compare some of these results to the solutions of corresponding equations on words. For both equations we study the maximal solutions, the centralizer and the conjugator. We present a fixed point method that we can use to search these maximal solutions and analyze the reasons why this method is not successful for all languages. We give also several examples to illustrate the behaviour of this method.

Verkkovaihtosuuntaajan vektorisäädön toteutus FPGA-piirillä

Verkkovaihtosuuntaajalla pystytään muuntamaan tasajännite vaihtojännitteeksi ja päinvastoin. Verkkovaihtosuuntaajan toiminta perustuu tehokytkinten ohjaukseen ja sopivan modulointimenetelmän käyttöön. Vektorisäädössä vaihtosuuntaajanvirrat ja jännitteet esitetään kompleksitasossa, jolloin virta- ja jännitekomponentit voidaan esittää vektoreina. Vektorisäädössä verkkovaihtosuuntaajan ohjaustoteutetaan laskemalla kompleksitasossa vektoreille arvot, jotka tuottavat vaihtosuuntaajan lähtöön halutun vektorin. Koska FPGA-piirit mahdollistavat nopean rinnakkaisen laskennan, soveltuvat ne hyvin vektorisäädön toteuttamiseen. FPGA-piirien rakenteesta johtuen on säätöjärjestelmän suunnittelussa huomioitava kiinteän pilkun lukujen riittävä bittileveys ja järjestelmän diskretointiaika. Työssä suunnitellaan verkkovaihtosuuntaajan vektorisäätö ja tutkitaan bittileveyden vaikutusta säädön toteuttamiseen FPGA-piirillä. Bittileveyden tarkasteluun esitetään käytettäväksi tilastollisia menetelmiä. Työssä tarkastellaan kiinteän pilkun järjestelmän ja liukulukujärjestelmän erosuureen tilastollisia tunnusmerkkejä sekä histogrammia. Tarkasteluissa huomattiin, että maksimivirhe itsessään ei tarjoa riittävästi tietoa erosuureen jakautumisesta. Näin ollen maksimivirhe ei ole kaikissa tilanteissa sovelias menetelmä riittävän bittitarkkuuden määrittämiseen. Työssä esitetään riittävän bittitarkkuuden määrittelemiseen käytettäväksi otossuureista otosvarianssia, keskipoikkeamaa ja vaihteluväliä.

Spectrally Tuned Lanthanide Photoluminescence for Point-of-Care Testing

Point-of-care (POC) –diagnostics is a field with rapidly growing market share. As these applications become more widely used, there is an increasing pressure to improve their performance to match the one of a central laboratory tests. Lanthanide luminescence has been widely utilized in diagnostics because of the numerous advantages gained by the utilization of time-resolved or anti-Stokes detection. So far the use of lanthanide labels in POC has been scarce due to limitations set by the instrumentation required for their detection and the shortcomings, e.g. low brightness, of these labels. Along with the advances in the research of lanthanide luminescence, and in the field of semiconductors, these materials are becoming a feasible alternative for the signal generation also in the future POC assays. The aim of this thesis was to explore ways of utilizing time-resolved detection or anti-Stokes detection in POC applications. The long-lived fluorescence for the time-resolved measurement can be produced with lanthanide chelates. The ultraviolet (UV) excitation required by these chelates is cumbersome to produce with POC compatible fluorescence readers. In this thesis the use of a novel light-harvesting ligand was studied. This molecule can be used to excite Eu(III)-ions at wavelengths extending up to visible part of the spectrum. An enhancement solution based on this ligand showed a good performance in a proof-of-concept -bioaffinity assay and produced a bright signal upon 365 nm excitation thanks to the high molar absorptivity of the chelate. These features are crucial when developing miniaturized readers for the time-resolved detection of fluorescence. Upconverting phosphors (UCPs) were studied as an internal light source in glucose-sensing dry chemistry test strips and ways of utilizing their various emission wavelengths and near-infrared excitation were explored. The use of nanosized NaYF :Yb3+,Tm3+-particles enabled the replacement of an external UV-light source with a NIR-laser and gave an additional degree of freedom in the optical setup of the detector instrument. The new method enabled a blood glucose measurement with results comparable to a current standard method of measuring reflectance. Microsized visible emitting UCPs were used in a similar manner, but with a broad absorbing indicator compound filtering the excitation and emission wavelengths of the UCP. This approach resulted in a novel way of benefitting from the non-linear relationship between the excitation power and emission intensity of the UCPs, and enabled the amplification of the signal response from the indicator dye.

The role of import intermediary companies in the Russian imports from the EU A case study of a Russian industrial company’s point of view on import intermediaries

The literature on agency suggests different implications for the use of export intermediaries. However, only few studies provide a view on import intermediaries. This thesis tries for its part to fill this research gap by studying the import intermediaries in the EU–Russia trade from a Russian industrial company’s point of view. The aim is to describe import intermediation and explain the need for import intermediary companies in the EU–Russia trade. The theoretical framework of this thesis originates from an article by Peng and York (2001), in which they study the performance of export intermediaries. This thesis applies resource-based theory, transaction cost theory and agency cost theory, following the idea of Peng and York. The resource-based theory approach is utilised for describing an ideal import intermediary company, and transaction cost theory provides a basis for understanding the benefits of using the services of import intermediary companies, while agency cost theory is applied in order to understand the risks the Russian industrial company faces when it decides to use the services of import intermediaries. The study is performed in the form of a case interview with a representative of a major Russian metallurgy company. The results of the study suggest that an ideal intermediary has the skills required specifically for the imports process, in order to save time and money of the principal company. The intermediary company helps reducing the amount of time the managers and the staff of the principal company use to make imports possible, thus reducing the salary costs and providing the possibility to concentrate on the company’s core competencies. The benefits of using the services of import intermediary companies are the reduced transaction costs, especially salary costs that are minimised because of the effectiveness and specialisation of import intermediaries. Intermediaries are specialised in the imports process and thus need less time and resources to organise the imports. They also help to reduce the fixed salary costs, because their services can be used only when needed. The risks of being misled by intermediaries are minimised by the competition on the import intermediary market. In case an intermediary attempts fraud, it gets replaced by its rival.

The role of import intermediary companies in the Russian imports from the EU A case study of a Russian industrial company’s point of view on import intermediaries

The literature on agency suggests different implications for the use of export intermediaries. However, only few studies provide a view on import intermediaries. This thesis tries for its part to fill this research gap by studying the import intermediaries in the EU–Russia trade from a Russian industrial company’s point of view. The aim is to describe import intermediation and explain the need for import intermediary companies in the EU–Russia trade. The theoretical framework of this thesis originates from an article by Peng and York (2001), in which they study the performance of export intermediaries. This thesis applies resource-based theory, transaction cost theory and agency cost theory, following the idea of Peng and York. The resource-based theory approach is utilised for describing an ideal import intermediary company, and transaction cost theory provides a basis for understanding the benefits of using the services of import intermediary companies, while agency cost theory is applied in order to understand the risks the Russian industrial company faces when it decides to use the services of import intermediaries. The study is performed in the form of a case interview with a representative of a major Russian metallurgy company. The results of the study suggest that an ideal intermediary has the skills required specifically for the imports process, in order to save time and money of the principal company. The intermediary company helps reducing the amount of time the managers and the staff of the principal company use to make imports possible, thus reducing the salary costs and providing the possibility to concentrate on the company’s core competencies. The benefits of using the services of import intermediary companies are the reduced transaction costs, especially salary costs that are minimised because of the effectiveness and specialisation of import intermediaries. Intermediaries are specialised in the imports process and thus need less time and resources to organise the imports. They also help to reduce the fixed salary costs, because their services can be used only when needed. The risks of being misled by intermediaries are minimised by the competition on the import intermediary market. In case an intermediary attempts fraud, it gets replaced by its rival.

A combined infrared/heat pump drying technology applied to a rotary dryer

Selostus: Yrttien ja vihannesten infrapunakuivaus rumpukuivurissa