El objetivo de la tesis es crear una herramienta de evaluación de prestaciones de redes de área local a nivel MAC para los mecanismos de acceso múltiple aleatorio y con control mediante paso de testigo. La metodología de evaluación se basa en la obtención de modelos analíticos y de simulación y su contratación con resultados experimentales. En acceso aleatorio se aportan modelos analíticos de características caudal-retardo explicitas para los protocolos CSMA/CD en función del concepto de persistencia del acceso.Del mecanismo de paso de testigo se estudia la dependencia estadística introducida por el mecanismo de acceso para los casos de estación sin almacenamiento y almacenamiento infinito.

This thesis addresses the challenge of understanding the typical star formation histories of red sequence galaxies, using linestrength indices, mass-to-light ratios and redshift evolution as complementary constraints on their stellar age distribution. We first construct simple parametric models of the star formation history that bracket a range of scenarios, and fit these models to the linestrength indices of low-redshift cluster red-sequence galaxies. For giant galaxies, we con firm the downsizing trend, i.e. the stellar populations are younger, on average, for lower σ galaxies. We find, however, that this trend flattens or reverses at σ < 70km/s. We then compare predicted stellar mass-to-light ratios with dynamical mass-to-light ratios derived from the Fundamental Plane, or by the SAURON group. For galaxies with σ ~ 70 km/s, models with a late 'frosting' of young stars and models with exponential star formation histories have stellar mass-to-light ratios that are larger than observed dynamical mass-to-light ratios by factors of 1.7 and 1.4, respectively, and so are rejected. The single stellar population (SSP) model is consistent with the Fundamental Plane, and requires a modest amount of dark matter (between 20% to 30%) to account for the difference between stellar and dynamical mass-to-light ratios. A model in which star formation was 'quenched' at intermediate ages is also consistent with the observations, although in this case less dark matter is required for low mass galaxies. We also find that the contribution of stellar populations to the 'tilt' of the Fundamental Plane is highly dependent on the assumed star-formation history: for the SSP model, the tilt of the FP is driven primarily by stellar-population effects. For a quenched model, two-thirds of the tilt is due to stellar populations and only one third is due to dark matter or non-homology. Comparing to high redshift cluster data, we find again the SSP and quenched models, as well as a model where strangulation begins at intermediate ages after a period of constant star formation, are preferred. They predict the recent faint-end build up of the red sequence, along with observed dwarf-to-giant ratios. Only the SSP model appears to predict the observed M/L evolution, but only if selection effects are carefully modeled.

―Green‖ odors comprise a group of eight structurally related aliphatic alkenals and alkenols which are characteristic for the odor of a wide variety of plant materials. Using an automated olfactometer, the olfactory detection thresholds for ―green‖ odors were determined in six CD-1 mice and compared with that of spider monkeys and human subjects. Detection threshold values for alcoholic ‖green‖ odors (cis-3-hexen-1-ol, trans-3-hexen-1-ol, trans-2-hexen-1-ol and 1-hexanol) ranged from 8.1 x 109 to 8.1 x 1011 molecules/cm3 and for aldehydic ‖green‖ odors (cis-3-hexenal, trans-3-hexenal, trans-2-hexenal and n-hexanal) , from 8.1 x 107 to 8.1 x 1011 molecules/ cm3 . Detection threshold values of ―green‖ odor with double bond ranged from 8.1 x 107 to 8.1 x 1011 molecules/cm3 and for ―green‖ odor without double bond ranged from 8.1 x 108 to 8.1 x 1011 molecules/cm3. Detection threshold value of cis- configured ―green‖ odors ranged from 8.1 x 108 to 8.1 x 1011 molecules/ cm3 and for trans- configured ―green‖ odors threshold value ranged from 8.1 x 107 to 8.1 x 1011 molecules/ cm3. Trans-2-hexenal with a double bond at C-2 position in its molecular structure yielded the lowest detection threshold value when compared the other ―green‖ odors (8.1 x 107 to 8.1 x 109 molecules /cm3) which shows not only the presence of double bond plays a major role in detection but the position of the double bond present. A comparison between the present data and data from the other species showed that CD-1 mice displayed lower detection thresholds for all ‖green‖ odors than human subjects and spider monkeys except for the cis-3-hexen-1-ol odor. These findings suggest that the differences in the threshold values between ―green‖ odors are due to the difference in the molecular structure like the presence of double bond and the position of double bond.

The purpose of this thesis was to examine the demand for cross directional control of basis weight on a board machine. To analyse the demand, changes made by the control system are studied. The significant changes were expected to be present when a major event occurred on the machine. The events classified as major were changes in basis weight, of grade or of coating blade. Break of board and stoppage of the machine were also included. These events can be seen as large disturbances to the machine. In order to identify the disturbances a methodology had to be developed. The methodology developed is to analyse the output from a model with the actuators of the control system as input and measurement of basis weight as output. The analysis of this output was done using the multivariate method of principal component analysis. The data analysed in this thesis was collected on-line from a board machine operating within the Stora Enso group. Over a period of 3 months, a total of 47 sets of data were collected, each set representing 12-14 hours. The data analysis shows that the variations in the control system are greater than the variation in the measured basis weight. This is a strong indication that the control system is needed and in order to find disturbances in the cross directional profile it is not enough only to analyse the final product, the control signals also have to be analysed. The large disturbances do not necessarily emerge from the major events as assumed. Other causes might havelarger impact to the process then first believed. One of the major obstacles in trying to explain the variations is that the basis weight is controlled by using the centre layer of the board but measured on the final product. This leads to the fact that the errors seen by the measuring system can result from anything on the machine and be compensated by basis weight in the centre layer of the board.

This thesis addresses the challenge of understanding the typical star formation histories of red sequence galaxies, using linestrength indices, mass-to-light ratios and redshift evolution as complementary constraints on their stellar age distribution. We first construct simple parametric models of the star formation history that bracket a range of scenarios, and fit these models to the linestrength indices of low-redshift cluster red-sequence galaxies. For giant galaxies, we con firm the downsizing trend, i.e. the stellar populations are younger, on average, for lower σ galaxies. We find, however, that this trend flattens or reverses at σ < 70km/s. We then compare predicted stellar mass-to-light ratios with dynamical mass-to-light ratios derived from the Fundamental Plane, or by the SAURON group. For galaxies with σ ~ 70 km/s, models with a late 'frosting' of young stars and models with exponential star formation histories have stellar mass-to-light ratios that are larger than observed dynamical mass-to-light ratios by factors of 1.7 and 1.4, respectively, and so are rejected. The single stellar population (SSP) model is consistent with the Fundamental Plane, and requires a modest amount of dark matter (between 20% to 30%) to account for the difference between stellar and dynamical mass-to-light ratios. A model in which star formation was 'quenched' at intermediate ages is also consistent with the observations, although in this case less dark matter is required for low mass galaxies. We also find that the contribution of stellar populations to the 'tilt' of the Fundamental Plane is highly dependent on the assumed star-formation history: for the SSP model, the tilt of the FP is driven primarily by stellar-population effects. For a quenched model, two-thirds of the tilt is due to stellar populations and only one third is due to dark matter or non-homology. Comparing to high redshift cluster data, we find again the SSP and quenched models, as well as a model where strangulation begins at intermediate ages after a period of constant star formation, are preferred. They predict the recent faint-end build up of the red sequence, along with observed dwarf-to-giant ratios. Only the SSP model appears to predict the observed M/L evolution, but only if selection effects are carefully modeled.

Using a conditioning paradigm and an automated olfactometer, I investigated the olfactory sensitivity of five CD-1 mice for seven aromatic aldehydes. With two of the stimuli (3-phenylpropanal and canthoxal), the animals discriminated concentrations as low as 10 ppb (parts per billion) from the odorless solvent and with four of the stimuli (helional, cyclamal, lilial and lyral) they discriminated concentrations as low as 1 ppb, with single individuals even scoring better. All five animals yielded the by far lowest threshold value with bourgeonal and discriminated a concentration of 0.1 ppq (parts per quadrillion) from the odorless solvent. The detection threshold values for aromatic aldehydes were found to be affected by the type of functional groups and oxygen moiety attached to the benzene ring. A comparison of the present data with those obtained in other species found no clear correlation between olfactory sensitivity and the size of the olfactory receptor repertoire.

The olfactory sensitivity of five male CD-1 mice (Mus musculus) for six amino acids was determined using an operant conditioning paradigm. All animals significantly distinguished dilutions as low as 0.01 mM L-cysteine, 3.3 mM L-methionine, 10 mM L-proline, 0.03 mM D-cysteine, 0.3 mM D-methionine and 10 mM D-proline from the odorless solvent, with individual animals displaying even lower detection thresholds. Among the three different L-forms of the amino acids the mice were most sensitive for cysteine and least sensitive for proline, and among the three D-forms the animals displayed a lower sensitivity for D-proline compared to D-cysteine and D-methionine. A comparison between the present data and results obtained with other species showed that the CD-1 mice displayed a higher sensitivity than human subjects and spider monkeys with three (L-Cysteine, D-cysteine and L-proline) of the six amino acids. Results from this report support the idea that the number of functional olfactory receptor genes is not suitable to predict a species’ olfactory sensitivity.

The aim of this thesis is to analyze Ukrainian foreign policy and its domestic sources since 1991, with a focus on the post-Orange Revolution era. The thesis argues that contrary to neo-realist approaches to the study of Ukrainian foreign policy, in the final analysis, it is Ukraine&#039 / s domestic factors which determines the direction of Ukrainian foreign policy in the post-Soviet era. This thesis demonstrates that the existing neo-realist studies of Ukrainian foreign policy exaggerates the role of external factors and neglects the crucial role of domestic factors in Ukrainian foreign policy. The thesis begins with an introduction, which is followed by the second chapter on the interaction between domestic and external factors in Ukrainian foreign policy in the pre-Orange Revolution era. The third chapter examines the characteristics of Ukrainian foreign policy in the post-Orange Revolution era. The following four chapters discuss the impact of political, economic and cultural factors on Ukrainian foreign policy as well as the Crimean question. Finally the last chapter will be the conclusion of this thesis.

The catching-up economies are unable to obtain the same power and financial status as that of the developed countries are primarily due to the less technological advancement. The research integrates the related facts and models on the development on high-tech of those of catching-up economies. A feasible strategic analysis structure is proposed serving as recommended guideline for the high-tech industries in those catching-up economies. Utilizing the CD/DVDs, semi-conductors and biological technology industries, all from Taiwan, as examples, to illustrate how the catching-up economies may structure the high-tech industries as well as how to develop strategies for the development of those three types of industries in Taiwan. The developed countries have accumulated the ability and resources from the past centuries to build the ability of R&D innovation, processing innovation, and assembly innovation in sequence. The catching-up economies must initially proceed with the method of reverse engineering. The step initiates with creating the assembly innovation and ends with research pertinent to the utilization of intensive brain-power. The research studies categorizes and divides the internal development of industry into four periods: the emerging period, the growing period, the expanding period, and the maturing period. The catching-up economies must overcome the various difficulties in order to reach the maturing period; and ultimately be able to obtain the same status as those industries of developed countries.

This paper presents the results of servo designs for optical disk drives which consist of a dual-input/single-output (DISO) actuator; both a sledge actuator and a voice coil motor contribute to a radial movement of the spot on the disk. DISO systems are subset of multi-input/multi-output (MIMO) systems and thus the servo engineer can apply the design methods developed for MIMO controller design to the DISO compensator problems. These techniques include H2 , H¡Û and £g-synthesis. However, in order to obtain insights into the controller elements, in this study we prefer the H¡Û loop-shaping approach. Here, the focus is on stability and disturbance rejection. The method is presented for a master-slave control scheme in tracking servo, a parallel scheme in seeking servo, and a unit-feedback scheme in focusing servo. The maximum stability margin can be obtained in H¡Û loop-shaping algorithm. Furthermore, a robust controller guarantees to stabilize it would be carried out. Finally, computer simulation results are provided to show that the shaking disturbance due to the run-out of disk can be significantly attenuated and a good tracking performance can be achieved by the developed controller.