The objective of this work is to investigate the structures of two nucleotide binding proteins: mevalonate kinase (MVK) and FtsZ. MVK is the key enzyme involved in terpenoid biosynthesis. In this study, we solved the crystal structures of the M. jannaschii MVK apoprotein, as well as the protein in complex with ligands. Its fold was analyzed and firmly established within the GHMP kinase family, in which homoserine kinase (HSK), phosphomevalonate kinase and galactokinase also belong. Structural analysis in combination with enzyme kinetics studies revealed the mechanism of this enzyme upon substrate binding, catalysis and inhibition. In particular, the phosphate-binding loop was found to be critically involved in the binding of nucleotides and terpenoids, via the interaction with a di-phosphate moiety from the ligand. An enzymatic reaction mechanism was constructed based on our structural data and it is consistent with kinetics studies from the literature. In this mechanism, the invariant residue Asp 155 functions as a general base that increases the nucleophilicity of the phosphoryl acceptor. Finally, a virtual screening study has been performed to explore the ligand binding potential of MVK. Compounds predicted to bind MVK were tested and analyzed. FtsZ is a prokaryotic homologue of tubulin that forms the apparatus for bacterial cell division. The structure of a crystal filament of the M. tuberculosis FtsZ complexed with GDP was described in this study. It shows an anti-parallel, left-handed double helical architecture. Compared with the straight crystal filament revealed earlier by other groups, the catalytic T7 loop in our structure is found to be outside the nucleotide binding site, indicating the GTPase is inactive. Furthermore, the buried surface area in our crystal filament is less, probably suggesting the helical FtsZ filament is less stable. We therefore proposed that the hydrolysis of GTP and the releasing of the γ-phosphate group will trigger the rearrangement of the FtsZ fibler, characterized by the exclusion of the T7 loop, which might lead to a less stable helical filament and would be the first step for the disassembly of FtsZ polymer.

Vår uppgift var att praktiskt genomföra och utvärdera två kalibreringsmetoder för modväxlande kammare hos Saab Avionics AB i Linköping. En metod som Saab Avionics använder och en metod enligt europeisk civil flygstandard, EUROCAE ED- 14D kapitel 20.6. Uppgiften löstes genom att utföra mätningar enligt de två kalibreringsmetoderna och därefter analysera mätdata i MatLab. Vi hann med att göra Saab Avionics kalibreringsmetod i samtliga mätpunkter som krävdes för utvärderingen, men bara drygt halva kalibreringen enligt europeisk civil flygstandard. Utifrån de mätningar vi gjort kan vi dra följande slutsatser: Båda kalibreringsmetoderna säger att Saab Avionics modväxlande kammare uppfyller respektive krav när den är olastad. Båda metoderna säger också att kammaren inte uppfyller kraven när den är lastad. Däremot visar Saab Avionics kalibreringsmetod inte samma resultat i alla demätpunkter vi jämfört när kammaren var lastad och den kan därför inte anses vara tillförlitlig i sin nuvarande form. Kalibreringsmetoderna kan inte anses likvärdiga som de ser ut idag. / Our assignment was to perform and evaluate two calibration methods for reverberation chambers at Saab Avionics AB in Linköping. One method used by Saab Avionics and one according to the standard EUROCAE ED-14D chapter 20.6. The problem was solved by performing measurements according to the two methods and evaluating the data using MatLab. We managed to carry out the Saab Avionics calibration method in all of the measuring points required for the evaluation, but only half of the calibration according to EUROCAE ED-14D. From the measurements that we have performed we can draw the following conclusions: Both of the calibration methods state that the Saab Avionics reverberation chamber fulfils the requirements when it is unloaded. Both of the methods also state that the chamber does not fulfil the requirements when it is loaded. However the Saab Avionics calibration method does not give the same result in all of the measuring points that we compared when the chamber was loaded and it can therefore not be considered to be reliable in its present form. The calibration methods cannot be considered to be equal as they are today.

<p>Vår uppgift var att praktiskt genomföra och utvärdera två kalibreringsmetoder för modväxlande kammare hos Saab Avionics AB i Linköping. En metod som Saab Avionics använder och en metod enligt europeisk civil flygstandard, EUROCAE ED- 14D kapitel 20.6. </p><p>Uppgiften löstes genom att utföra mätningar enligt de två kalibreringsmetoderna och därefter analysera mätdata i MatLab. </p><p>Vi hann med att göra Saab Avionics kalibreringsmetod i samtliga mätpunkter som krävdes för utvärderingen, men bara drygt halva kalibreringen enligt europeisk civil flygstandard. </p><p>Utifrån de mätningar vi gjort kan vi dra följande slutsatser: Båda kalibreringsmetoderna säger att Saab Avionics modväxlande kammare uppfyller respektive krav när den är olastad. </p><p>Båda metoderna säger också att kammaren inte uppfyller kraven när den är lastad. </p><p>Däremot visar Saab Avionics kalibreringsmetod inte samma resultat i alla demätpunkter vi jämfört när kammaren var lastad och den kan därför inte anses vara tillförlitlig i sin nuvarande form. Kalibreringsmetoderna kan inte anses likvärdiga som de ser ut idag. </p> / <p>Our assignment was to perform and evaluate two calibration methods for reverberation chambers at Saab Avionics AB in Linköping. One method used by Saab Avionics and one according to the standard EUROCAE ED-14D chapter 20.6. </p><p>The problem was solved by performing measurements according to the two methods and evaluating the data using MatLab. </p><p>We managed to carry out the Saab Avionics calibration method in all of the measuring points required for the evaluation, but only half of the calibration according to EUROCAE ED-14D. </p><p>From the measurements that we have performed we can draw the following conclusions: Both of the calibration methods state that the Saab Avionics reverberation chamber fulfils the requirements when it is unloaded. </p><p>Both of the methods also state that the chamber does not fulfil the requirements when it is loaded. </p><p>However the Saab Avionics calibration method does not give the same result in all of the measuring points that we compared when the chamber was loaded and it can therefore not be considered to be reliable in its present form. The calibration methods cannot be considered to be equal as they are today.</p>

Die Elektromagnetische Verträglichkeit (EMV) betrachtet die Fähigkeit eines elektrischen Gerätes, in seiner elektromagnetischen Umgebung störungsfrei zu funktionieren, ohne diese dabei unzulässig zu stören. Zur Prüfung der Elektromagnetischen Verträglichkeit werden verschiedene Messumgebungen verwendet. Die Messung der strahlungsgebundenen Störfestigkeit und Störaussendung kann zum Beispiel in einer Modenverwirbelungskammer (MVK) erfolgen. Bei der Störfestigkeitsmessung wird der Prüfling einem externen Prüffeld ausgesetzt und untersucht, ob dieser die definierten Kriterien für einen störungsfreien Betrieb erfüllt. Für das Prüffeld muss vor der Messung nachgewiesen werden, dass die Anforderungen an dessen Homogenität eingehalten werden. Einen entscheidenden Einfluss auf die Homogenität des Prüffeldes hat der sogenannte Rührer. Bei einer MVK handelt es sich prinzipiell um einen Hohlraumresonator, in den ein mechanischer Rührer, d.h. ein elektrisch großer, drehbarer Streukörper integriert wird. Durch die Drehung des Rührers verändert sich die Feldverteilung in der MVK, was auch als Verwirbelung bezeichnet wird. Prinzipiell ergibt sich für jede Stellung des Rührers ein inhomogenes Feld mit lokalen Minima und Maxima. Ein Ziel bei der Verwendung von Modenverwirbelungskammern ist es, mit Hilfe geeigneter Verfahren Rührerstellungen zu finden, deren Feldverteilungen in Überlagerung ein möglichst homogenes Prüffeld erzeugen. Zum Lehrstuhl für Theoretische Elektrotechnik und Elektromagnetische Verträglichkeit der Technischen Universität Dresden gehört seit 2010 eine Modenverwirbelungskammer. Die Charakterisierung dieser MVK sowie eine weiterführende Untersuchung zur Wahl der Rührerstellungen bilden die Schwerpunkte der vorliegenden Arbeit. / In 2010 the Chair of Electromagnetic Theory and Compatibility of Technical University Dresden could extend its laboratories by a reverberation chamber with the dimensions 5.3 m, 3.7m and 3.0 m. Since then, a detailed characterisation of the chamber as well as further investigations have been the main emphasis of the authors research. The submitted doctoral thesis presents the obtained results. With the design, the fundamentals of operation and further characterisation of the reverberation chamber, given in Chapter 1 and 2, it aims to give an introduction and better understanding of reverberation chambers. On this basis, the authors research focused on methods for determining the independent stirrer positions in reverberations chambers. The results of the investigations are presented and summarised in chapter 3. One scope of Electromagnetic Compatibility are radiated immunity measurements. Besides the GTEM cell and the anechoic chamber the reverberation chamber gains in importance as an alternative measurement environment. A reverberation chamber is a shielded room with reflecting walls and one or more integrated mechanical stirrers. By rotating the stirrer the spatial boundary conditions for the electromagnetic field quantities are altered. The resulting change of the spatial field distribution depends on the location within the chamber and the geometry of the stirrer. Each stirrer position yields an inhomogeneous field distribution created by interfering waves. A general aim is to find a set of stirrer positions, whose superimposed field distributions create a more uniform test field. In practice, the given requirements for the homogeneity of the test field shall, with regards to an optimisation of measurement time, be realized with a minimum number of stirrer positions. In this context the term ’independent stirrer positions’ was established and describes stirrer positions, whose field distributions are linearly uncorrelated and therefore assumed to be practical for creating a more homogeneous test field using only a minimal number of stirrer positions. A general method for determining the number of independent stirrer positions in reverberation chambers is presented. The method uses a certain number of measurement positions in a defined test volume in order to characterize the spatial field distribution inside the chamber. Using the Pearson correlation coefficient the field distributions of the stirrer positions are tested for linear correlation and pairs of independent stirrer positions are determined. On this basis, cliques of pairwise independent stirrer positions are identified using appropriate algorithms. It is shown that the general method yields detailed information about the number and distribution of the independent stirrer positions and is therefore particularly suitable to evaluate other methods. Finally, the standard method according to IEC 61000-4-21 as well as selected alternative methods, that have been proposed in the past, are evaluated and compared based on the results of the general method.

Vårt samhälle har genomgått stora förändringar då det rör sig teknik. Många områden i dagens samhälle blev digitaliserade och Vården, vår hälsa blev inte ett undantag. Landstinget tillhandahåller ett IT- system eller e- tjänst, som möjliggör patienten att boka/ omboka tid, förnya recept, beställa sina patientjournaler och med mera. E- tjänsten Mina Vårdkontakter (MVK) skapades för drygt 10 år sedan. Tjänsten vänder sig till alla medborgare, oavsett dator- och Internetanvändningserfarenhet, kön och ålder. Eftersom alla medborgare inte är lika vana IT- användare och därför ett sådant system bör vara så användarvänlig som möjligt. Detta arbete syftar på att hitta brister i MVK och hitta förslag på förbättringar utifrån användbarhetsprinciper. Metoder som användes i detta arbete är kombination av kvalitativ och kvantitativ metod. Därför utvärderade jag e- tjänsten MVK, genom att genomföra ett antal användbarhetstester. Testpersoner i detta arbete var både män och kvinnor i olika åldrar, har olika erfarenhet av dator- och Internetanvändning. Mina testfrågade fick ett antal enkla uppgifter, som jag ansåg kan ha några brister. Det svåraste av alla uppgifter var att Hitta MVK på lg.se webbsida. Men det var inte heller lätt att hitta hjälp på MVK. Den bästa tjänsten av alla som finns på MVK var att avboka/ omboka tiden och förnya recept- funktionen. Med hjälp av Time- on- task observerade jag också att oerfarna personer tar alltid längre tid att utföra vissa uppgifter jämfört med experten och med erfarna testpersoner. Och det är just för dem man ska förbättra e- tjänsten för att det skulle vara så enkelt som möjligt att använda e- tjänsten och personer skulle trivas med systemet. Efter genomfört arbete identifierades förslag på förbättringar av e- tjänsten, samt man kunde ge förslag på framtida forskning. Framtid forskning kan vara en ny utvärdering av bara en grupp oerfarna användare i olika åldrar. Man kan också undersöka hur den grafiska designen ser ut och hur det går att navigera i MVK. Eller så kan man göra en ny utvärdering efter den planerade uppdateringen av MVK som skulle ske om drygt en månad, enligt MVK- utvecklare. / Our society has undergone significant changes as new techniques came into our lives. Many areas of today’s society have digitalized in very short period and even healthcare sector is not exception. The County Council (Landstinget) provides an IT- system or e- service (MVK), which allows patients to book/ cancel appointments, renew prescriptions, order Patient Medical Records and much more. E- service was created just over 10 years ago. The service is aimed to all citizens, regardless of Computer- and Internet experience, gender and age. Since not all citizens are experienced in usage of IT, such system should be as easier and as user friendly as possible. This work is aimed to find weaknesses in MVK and find suggestions for improvement based on usability principles. Methods used in this work the combination of qualitative and quantitative methods. Therefore, I evaluated the service MVK, by implementing a number of usability tests. Test persons in this work were both men and women of different ages and different Computer- and Internet experiences. Test persons got a number of simple tasks, in which I felt we might find some faults. The most difficult of all was to find MVK on lg.se website. But it was not easy either to find Help on MVK. The best service of all available on MVK is to cancel/ reschedule the appointment and renew- prescription function. By using Time- on- task, I observed that inexperienced computer and internet users take longer time to perform certain tasks, compared with the expert and with other test takers. And that is right for them we should improve the system so that it would be easy for them to use it. In this work I could identify suggestions to improve the e- service, and could give suggestions to future research. Future research may be a reassessment of just a group of inexperienced users of different ages. We can also examine how the graphic design looks like and how it is to navigate on MVK. Or we can also re- evaluate e- service after the planned updates of MVK that would be carried out in a month, according to MVK developers.

Die Elektromagnetische Verträglichkeit (EMV) betrachtet die Fähigkeit eines elektrischen Gerätes, in seiner elektromagnetischen Umgebung störungsfrei zu funktionieren, ohne diese dabei unzulässig zu stören. Zur Prüfung der Elektromagnetischen Verträglichkeit werden verschiedene Messumgebungen verwendet. Die Messung der strahlungsgebundenen Störfestigkeit und Störaussendung kann zum Beispiel in einer Modenverwirbelungskammer (MVK) erfolgen. Bei der Störfestigkeitsmessung wird der Prüfling einem externen Prüffeld ausgesetzt und untersucht, ob dieser die definierten Kriterien für einen störungsfreien Betrieb erfüllt. Für das Prüffeld muss vor der Messung nachgewiesen werden, dass die Anforderungen an dessen Homogenität eingehalten werden. Einen entscheidenden Einfluss auf die Homogenität des Prüffeldes hat der sogenannte Rührer. Bei einer MVK handelt es sich prinzipiell um einen Hohlraumresonator, in den ein mechanischer Rührer, d.h. ein elektrisch großer, drehbarer Streukörper integriert wird. Durch die Drehung des Rührers verändert sich die Feldverteilung in der MVK, was auch als Verwirbelung bezeichnet wird. Prinzipiell ergibt sich für jede Stellung des Rührers ein inhomogenes Feld mit lokalen Minima und Maxima. Ein Ziel bei der Verwendung von Modenverwirbelungskammern ist es, mit Hilfe geeigneter Verfahren Rührerstellungen zu finden, deren Feldverteilungen in Überlagerung ein möglichst homogenes Prüffeld erzeugen. Zum Lehrstuhl für Theoretische Elektrotechnik und Elektromagnetische Verträglichkeit der Technischen Universität Dresden gehört seit 2010 eine Modenverwirbelungskammer. Die Charakterisierung dieser MVK sowie eine weiterführende Untersuchung zur Wahl der Rührerstellungen bilden die Schwerpunkte der vorliegenden Arbeit. / In 2010 the Chair of Electromagnetic Theory and Compatibility of Technical University Dresden could extend its laboratories by a reverberation chamber with the dimensions 5.3 m, 3.7m and 3.0 m. Since then, a detailed characterisation of the chamber as well as further investigations have been the main emphasis of the authors research. The submitted doctoral thesis presents the obtained results. With the design, the fundamentals of operation and further characterisation of the reverberation chamber, given in Chapter 1 and 2, it aims to give an introduction and better understanding of reverberation chambers. On this basis, the authors research focused on methods for determining the independent stirrer positions in reverberations chambers. The results of the investigations are presented and summarised in chapter 3. One scope of Electromagnetic Compatibility are radiated immunity measurements. Besides the GTEM cell and the anechoic chamber the reverberation chamber gains in importance as an alternative measurement environment. A reverberation chamber is a shielded room with reflecting walls and one or more integrated mechanical stirrers. By rotating the stirrer the spatial boundary conditions for the electromagnetic field quantities are altered. The resulting change of the spatial field distribution depends on the location within the chamber and the geometry of the stirrer. Each stirrer position yields an inhomogeneous field distribution created by interfering waves. A general aim is to find a set of stirrer positions, whose superimposed field distributions create a more uniform test field. In practice, the given requirements for the homogeneity of the test field shall, with regards to an optimisation of measurement time, be realized with a minimum number of stirrer positions. In this context the term ’independent stirrer positions’ was established and describes stirrer positions, whose field distributions are linearly uncorrelated and therefore assumed to be practical for creating a more homogeneous test field using only a minimal number of stirrer positions. A general method for determining the number of independent stirrer positions in reverberation chambers is presented. The method uses a certain number of measurement positions in a defined test volume in order to characterize the spatial field distribution inside the chamber. Using the Pearson correlation coefficient the field distributions of the stirrer positions are tested for linear correlation and pairs of independent stirrer positions are determined. On this basis, cliques of pairwise independent stirrer positions are identified using appropriate algorithms. It is shown that the general method yields detailed information about the number and distribution of the independent stirrer positions and is therefore particularly suitable to evaluate other methods. Finally, the standard method according to IEC 61000-4-21 as well as selected alternative methods, that have been proposed in the past, are evaluated and compared based on the results of the general method.

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