954 resultados para Direct Current Machine Control


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Suunniteltiin ja rakennettiin suoraa vääntömomenttisäätöä soveltava taajuudenmuuttajakäyttö oikosulkumoottorin ohjaukseen korvaamaan passiivinen jarrukäyttö. Laite on kuntoutuslaite, jolla tehdään lihasvoiman mittauksia ja voimaharjoituksia. Selvitettiin kaupallisten moottoreiden ja taajuudenmuuttajien suoritusominaisuuksia ja tämän perusteella valittiin käyttöön sopivat laitteet. Työssä esitetään kaksi oikosulkumoottorin ohjaustapaa: vektorisäätö ja suora vääntömomenttisäätö. Merkittävin osa tästä työstä käsittelee - tarkan turvallisuussuunnitelman lisäksi - kuntoutuslaitteen prototyypin komponentteja, kokoamista ja suoritustestien tuloksia.

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Avec plus de 100000 transplantations d'organes solides (TOS) par année dans le monde, la transplantation d'organes reste actuellement l'un des meilleurs traitements disponibles pour de nombreuses maladies en phase terminale. Bien que les médicaments immunosuppresseurs couramment utilisés soient efficaces dans le contrôle de la réponse immune engendrant le rejet aigu d'une greffe, la survie du greffon à long terme ainsi que la présence d'effets secondaires indésirables restent un enjeu considérable en clinique. C'est pourquoi il est nécessaire de trouver de nouvelles approches thérapeutiques innovantes permettant de contrôler la réponse immunitaire et ainsi d'améliorer les résultats à long terme. L'utilisation des lymphocytes T régulateurs (Treg), suppresseurs naturels de la réponse inflammatoire, a fait l'objet de nombreuses études ces dix dernières années, et pourrait être considérée comme un moyen intéressant d'améliorer la tolérance immunologique de la greffe. Cependant, l'un des obstacles de l'utilisation des Treg comme agent thérapeutique est leur nombre insuffisant non seulement en conditions normales, mais en particulier lors d'une forte réponse immune avec expansion de cellules immunitaires alloréactives. En raison des limitations techniques connues pour l'induction des Treg ex-vivo ou in vitro, nous avons dédié la première partie du travail de thèse à la détermination de l'efficacité de l'induction des Treg in vivo grâce à l'utilisation d'un complexe protéique IL-2/JES6-1 (IL2c). Nous avons montré que l'expansion des Treg par IL2c permettait d'augmenter la survie du greffon sur un modèle murin de transplantation de peau avec mismatch entre le donneur et le receveur pour le complexe majeur d'histocompatibilité (CMH). De plus, nous avons vu qu'en combinant IL2c à une inhibition à court terme de la voie de co-stimulation CD40L-CD40 (anti-CD154/MRl, administré au moment de la transplantation) pour empêcher l'activation des lymphocytes T, il est possible d'induire une tolérance robuste à long terme. Finalement, nos résultats soulignent l'importance de cibler une voie de co-stimulation bien particulière. En effet, l'utilisation d'IL2c combinée au blocage de la co-stimulation CD28-B7.1/2 (CTLA-4 Ig) n'induit qu'une faible prolongation de la survie de la greffe et n'induit pas de tolérance. L'application chez l'humain des traitements induisant la tolérance dans des modèles expérimentaux murins ou de primates n'a malheureusement pas montré de résultats probants en recherche clinique ; une des principales raisons étant la présence de lymphocytes B et T mémoires provenant du systeme d immunité acquise. C est pourquoi nous avons testé si la combinaison d'IL2c et MR1 améliorait la survie de la greffe dans des souris pré¬sensibilisées. Nous avons trouvé qu'en présence de lymphocytes B et T mémoires alloréactifs, l'utilisation d'IL2c et MR1 permettait une amélioration de la survie de la greffe de peau des souris immunocompétentes mais comparé aux souris receveuses naïves, aucune tolérance n'a pu être induite. Toutefois, l'ajout d'un traitement anti-LFA-1 (permettant de bloquer la circulation des lymphocytes T activées) a permis d'améliorer de manière significative la survie de la greffe. Cependant, le rejet chronique, dû à la présence de lymphocytes B activés/mémoires et la production d'anticorps donneur-spécifiques, n'a pas pu être évité. Cibler l'activation des lymphocytes T est la stratégie immunothérapeutique prépondérente après une TOS. C'est pourquoi dans la deuxième partie de cette thèse nous nous sommes intéressés au système de signalisation d'un récepteur des lymphocytes T qui dépend de la paracaspase Malti en tant que nouvelle stratégie immunosuppressive pour le contrôle des lymphocytes T alloréactifs. Nous avons montré que bien que l'inhibition de la signalisation du lymphocyte T en aval de Malti induise une tolérance envers un greffon de peau avec incompatibilités antigéniques mineures, cela ne permet cependant qu'une régulation partielle de l'alloréponse contre des antigènes du CMH. Nous nous sommes aussi intéressés spécifiquement à l'activité protéolytique de Malti. L'inhibition constitutive de l'activité protéolytique de Malti chez les souris Malti-ki s'est révélée délétère pour l'induction de la tolérance car elle diminue la fonction des Treg et augmente l'alloréactivité des cellules Thl. Cependant, lors de l'utilisation d'un inhibiteur peptidique de l'activité protéase de Malti in vitro, il a été possible d'observer une atténuation de l'alloéactivité des lymphocytes T ainsi qu'un maintien de la population des Treg existants. Ces résultats nous laissent penser que des études plus poussées sur le rôle de la signalisation médiée par Malti seraient à envisager dans le domaine de la transplantation. En résumé, les résultats obtenus durant cette thèse nous ont permis d'élucider certains mécanismes immunologiques propres à de nouvelles stratégies thérapeutiques potentielles dont le but est d'induire une tolérance lors de TOS. De plus, ces résultats nous ont permis de souligner l'importance d'utiliser des modèles davantage physiologiques contenant, notamment en tenant compte des lymphocytes B et T mémoires alloréactifs. -- Organ transplantation remains the best available treatment for many forms of end-stage organ diseases, with over 100,000 solid organ transplantations (SOT) occurring worldwide eveiy year. Although the available immunosuppressive (IS) drugs are efficient in controlling acute immune activation and graft rejection, the off-target side effects as well as long-term graft and patient survival remain a challenge in the clinic. Hence, innovative therapeutic approaches are needed to improve long-term outcome across immunological barriers. Based on extensive experimental data obtained over the last decade, it is tempting to consider immunotherapy using Treg; the natural suppressors of overt inflammatory responses, in promoting transplantation tolerance. The first hurdle for the therapeutic use of Treg is their insufficient numbers in non- manipulated individuals, in particular when facing strong immune activation and expanding alloreactive effector cells. Because of the limitations associated with current protocols aiming at ex-vivo expansion or in vitro induction of Treg, the aim of the first part of this thesis was to determine the efficacy of direct in vivo expansion of Treg using the IL-2/JES6- 1 immune complex (IL2c). We found that whilst IL2c mediated Treg expansion alone allowed the prolonged graft survival of fìlli MHC-mismatched skin grafts, its combination with short-term CD40L-CD40 co-stimulation blockade (anti-CD 154/MR1) to inhibit T cell activation administered at the time of transplantation was able to achieve long-term robust tolerance. This study also highlighted the importance of combining Treg based therapies with the appropriate co-stimulation blockade as a combination of IL2c and CD28-B7.1/2 co- stimulation blockade (CTLA-4 Ig) only resulted in slight prolongation of graft survival but not tolerance. The translation of tolerance induction therapies modelled in rodents into non-human primates or into clinical trials has seldom been successful. One main reason being the presence of pre-existing memory T- and B-cells due to acquired immunity in humans versus laboratory animals. Hence, we tested whether IL2c+MRl could promote graft survival in pre-sensitized mice. We found that in the presence of alloreactive memory T- and B-cells, IL2c+MRl combination therapy could prolong MHC-mismatched skin graft survival in immunocompetent mice but tolerance was lost compared to the naïve recipients. The addition of anti-LF A-1 treatment, which prevents the trafficking of memory T cells worked synergistically to significantly further enhance graft survival. However, late rejection mediated by activated/memory B cells and persistent donor-specific alloantibodies still occurred. Immunotherapeutic strategies targeting the activation of T cells are the cornerstone in the current immunosuppressive management after SOT. Therefore, in the next part of this thesis we investigated the paracaspase Malti-dependent T-cell receptor signalling as a novel immunosuppressive strategy to control alloreactive T cells in transplantation. We observed that although the inhibition of Malti downstream T signalling lead to tolerance of a minor H- mismatch skin grafts, it was however not sufficient to regulate alloresponses against MHC mismatches and only prolonged graft survival. Furthermore, we investigated the potential of more selectively targeting the protease activity of Malti. Constitutive inhibition of Malti protease activity in Malti-ki mice was detrimental to tolerance induction as it diminished Treg function and increased Thl alloreactivity. However, when using a small peptide inhibitor of Malti proteolytic activity in vitro, we observed an attenuation of alloreactive T cells and sparing of the pre-existing Treg pool. This indicates that further investigation of the role of Malti signalling in the field of transplantation is required. Collectively, the findings of this thesis provide immunological mechanisms underlying novel therapeutic strategies for the promotion of tolerance in SOT. Moreover, we highlight the importance of testing tolerance induction therapies in more physiological models with pre-existing alloreactive memory T and B cells.

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In the rat utricle, synaptic contacts between hair cells and the nerve fibers arising from the vestibular primary neurons form during the first week after birth. During that period, the sodium-based excitability that characterizes neonate utricle sensory cells is switched off. To investigate whether the establishment of synaptic contacts was responsible for the modulation of the hair cell excitability, we used an organotypic culture of rat utricle in which the setting of synapses was prevented. Under this condition, the voltage-gated sodium current and the underlying action potentials persisted in a large proportion of nonafferented hair cells. We then studied whether impairment of nerve terminals in the utricle of adult rats may also affect hair cell excitability. We induced selective and transient damages of afferent terminals using glutamate excitotoxicity in vivo. The efficiency of the excitotoxic injury was attested by selective swellings of the terminals and underlying altered vestibular behavior. Under this condition, the sodium-based excitability transiently recovered in hair cells. These results indicate that the modulation of hair cell excitability depends on the state of the afferent terminals. In adult utricle hair cells, this property may be essential to set the conditions required for restoration of the sensory network after damage. This is achieved via re-expression of a biological process that occurs during synaptogenesis.

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Industry's growing need for higher productivity is placing new demands on mechanisms connected with electrical motors, because these can easily lead to vibration problems due to fast dynamics. Furthermore, the nonlinear effects caused by a motor frequently reduce servo stability, which diminishes the controller's ability to predict and maintain speed. Hence, the flexibility of a mechanism and its control has become an important area of research. The basic approach in control system engineering is to assume that the mechanism connected to a motor is rigid, so that vibrations in the tool mechanism, reel, gripper or any apparatus connected to the motor are not taken into account. This might reduce the ability of the machine system to carry out its assignment and shorten the lifetime of the equipment. Nonetheless, it is usually more important to know how the mechanism, or in other words the load on the motor, behaves. A nonlinear load control method for a permanent magnet linear synchronous motor is developed and implemented in the thesis. The purpose of the controller is to track a flexible load to the desired velocity reference as fast as possible and without awkward oscillations. The control method is based on an adaptive backstepping algorithm with its stability ensured by the Lyapunov stability theorem. As a reference controller for the backstepping method, a hybrid neural controller is introduced in which the linear motor itself is controlled by a conventional PI velocity controller and the vibration of the associated flexible mechanism is suppressed from an outer control loop using a compensation signal from a multilayer perceptron network. To avoid the local minimum problem entailed in neural networks, the initial weights are searched for offline by means of a differential evolution algorithm. The states of a mechanical system for controllers are estimated using the Kalman filter. The theoretical results obtained from the control design are validated with the lumped mass model for a mechanism. Generalization of the mechanism allows the methods derived here to be widely implemented in machine automation. The control algorithms are first designed in a specially introduced nonlinear simulation model and then implemented in the physical linear motor using a DSP (Digital Signal Processor) application. The measurements prove that both controllers are capable of suppressing vibration, but that the backstepping method is superior to others due to its accuracy of response and stability properties.

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Stromal fibroblast senescence has been linked to the aging-associated increase of tumors. However, in epithelial cancer, density and proliferation of cancer associated fibroblasts (CAF) are frequently increased, rather than decreased. We previously showed that genetic deletion or down-modulation of the canonical Notch effector CSL/RBP-JK in dermal fibroblasts is sufficient for CAF activation with consequent development of keratinocyte-derived tumors. We show here that CSL silencing induces senescence of primary fibroblasts from dermis, oral mucosa, breast and lung. CSL functions in these cells as direct repressor of multiple senescence- and CAF-effector genes. It also physically interacts with p53, repressing its activity. CSL is down-modulated in stromal fibroblasts of premalignant skin actinic keratosis lesions and squamous cell carcinomas (SCC), while p53 gene expression and function is down-modulated only in the latter, with paracrine influences of incipient cancer cells as a likely culprit. Concomitant loss of CSL and p53 overcomes fibroblast senescence, enhances CAF effector gene expression and promotes stromal and cancer cell expansion. The findings support a CAF activation/stromal co-evolution model under convergent CSL/p53 control of likely clinical relevance.

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NlmCategory="UNASSIGNED">This study is aimed at the determination of the measurement properties of the shoulder function B-B Score measured with a smartphone. This score measures the symmetry between sides of a power-related metric for two selected movements, with 100% representing perfect symmetry. Twenty healthy participants, 20 patients with rotator cuff conditions, 23 with fractures, 22 with capsulitis, and 23 with shoulder instabilities were measured twice across a six-month interval using the B-B Score and shoulder function questionnaires. The discriminative power, responsiveness, diagnostic power, concurrent validity, minimal detectable change (MDC), minimal clinically important improvement (MCII), and patient acceptable symptom state (PASS) were evaluated. Significant differences with the control group and significant baseline-six-month differences were found for the rotator cuff condition, fracture, and capsulitis patient groups. The B-B Score was responsive and demonstrated excellent diagnostic power, except for shoulder instability. The correlations with clinical scores were generally moderate to high, but lower for instability. The MDC was 18.1%, the MCII was 25.2%, and the PASS was 77.6. No floor effect was observed. The B-B Score demonstrated excellent measurement properties in populations with rotator cuff conditions, proximal humerus fractures, and capsulitis, and can thus be used as a routine test to evaluate those patients.

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Digitaalisten myyntikanavien käytön lisääntyminen suoramarkkinoinnissa ja kanavien tarjoamat mahdollisuudet ovat ajankohtainen aihe yritysmaailmassa. Digitalisoitumisen hyödyt yritykselle ovat myös uusi tutkimuskohde. Tutkimuksessa pyritään löytämään perinteisen ja digitaalisen kanavan erot sekä kuvaamaan sähköpostimyynnin erityispiirteet aikakauslehden tilausmyynnissä. Tutkimuksen näkökulmana on taloushallinnon kustannus-hyötytarkastelu. Tämän kvalitatiivisen tutkimuksen menetelmänä on tapaustutkimus ja kohdeyrityksenä Sanoma Magazines Finland Oy, jonka lehtituotteiden myynnin tietoja on kerätty pääasiassa havainnoimalla yrityksen eri järjestelmistä. Ilmiötä on tarkasteltu sähköiseen markkinointiin liittyvän lainsäädännön, strategia-ajattelun käsitteistön ja taloushallinnosta erityisesti kustannuslaskennan kautta. Empiriassa kuvataan kahden eri myyntikanavan myyntiprosessit. Vertailemalla eri kanavien viiden eri lehtituotteen kahden vuoden myynnin toimenpiteiden tunnuslukuja keskenään pyritään selvittämään ja kuvaamaan sähköpostimyynnin erityispiirteet.

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This study uses event-related brain potentials (ERPs) to investigate the electrophysiological correlates of numeric conflict monitoring in math-anxious individuals, by analyzing whether math anxiety is related to abnormal processing in early conflict detection (as shown by the N450 component) and/or in a later, response-related stage of processing (as shown by the conflict sustained potential; Conflict-SP). Conflict adaptation effects were also studied by analyzing the effect of the previous trial"s congruence in current interference. To this end, 17 low math-anxious (LMA)and 17 high math-anxious (HMA) individuals were presented with a numerical Stroop task. Groups were extreme in math anxiety but did not differ in trait or state anxiety or in simple math ability. The interference effect of the current trial (incongruent-congruent) and the interference effect preceded by congruence and by incongruity were analyzed both for behavioral measures and for ERPs. A greater interference effect was found for response times in the HMA group than in the LMA one. Regarding ERPs, the LMA group showed a greater N450 component for the interference effect preceded by congruence than when preceded by incongruity, while the HMA group showed greater Conflict-SP amplitude for the interference effect preceded by congruence than when preceded by incongruity. Our study showed that the electrophysiological correlates of numeric interference in HMA individuals comprise the absence of a conflict adaptation effect in the first stage of conflict processing (N450) and an abnormal subsequent up-regulation of cognitive control in order to overcome the conflict (Conflict-SP). More concretely, our study shows that math anxiety is related to a reactive and compensatory recruitment of control resources that is implemented only when previously exposed to a stimuli presenting conflicting information

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Online paper web analysis relies on traversing scanners that criss-cross on top of a rapidly moving paper web. The sensors embedded in the scanners measure many important quality variables of paper, such as basis weight, caliper and porosity. Most of these quantities are varying a lot and the measurements are noisy at many different scales. The zigzagging nature of scanning makes it difficult to separate machine direction (MD) and cross direction (CD) variability from one another. For improving the 2D resolution of the quality variables above, the paper quality control team at the Department of Mathematics and Physics at LUT has implemented efficient Kalman filtering based methods that currently use 2D Fourier series. Fourier series are global and therefore resolve local spatial detail on the paper web rather poorly. The target of the current thesis is to study alternative wavelet based representations as candidates to replace the Fourier basis for a higher resolution spatial reconstruction of these quality variables. The accuracy of wavelet compressed 2D web fields will be compared with corresponding truncated Fourier series based fields.

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Les pistolets à impulsion électrique (PIE) sont de plus en plus fréquemment utilisés en Europe ces dernières années, le modèle le plus connu étant le Taser®. Les connaissances scientifiques concernant les PIE et leurs effets potentiels restent toutefois limitées. Nous avons conduit une revue de littérature afin d'évaluer les implications potentielles de leur utilisation en termes de sécurité, de morbidité et de mortalité. Une exposition unique chez un individu sain peut généralement être considérée comme peu dangereuse. Les sujets à risque de complications sont les individus exposés à de multiples décharges, les personnes sous l'influence de substances psychoactives, ceux qui montrent des signes d'agitation extrême, ou encore les individus présentant des comorbidités médicales. L'éventail des complications pouvant survenir lors de leur exposition est large et inclut les lésions provoquées par les impacts des électrodes, les traumatismes liés à la chute induite par la paralysie transitoire ou des complications cardiovasculaires. Dans ce contexte, les personnes exposées doivent être examinées attentivement, et les éventuelles lésions traumatiques doivent être exclues. The use of electronic control devices (ECD), such as the Taser®, has increased in Europe over the past decade. However, scientific data concerning the potential health impact of ECD usage remains limited. We reviewed the scientific literature in order to evaluate the safety, mortality, and morbidity associated with ECD use. Exposure of a healthy individual to a single ECD electroshock can be considered generally safe. Complications can, however, occur if the patient is subject to multiple electroshocks, if the patient has significant medical comorbidities, or when exposure is associated with drug abuse or agitated delirium. The broad spectrum of potential complications associated with ECD exposure includes direct trauma caused by the ECD electrodes, injuries caused by the transient paralysis-induced fall, and cardiovascular events. An ECD-exposed patient requires careful examination during which traumatic injuries are actively sought out.

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This report has been written as part of the project “Toward improved quality – developing nurse’s continuing vocational training in hospitals and inpatient units”. Its overall goal is to ensure high quality, ethically appropriate and therapeutically effective interventions to enable nurses to manage distressed and disturbed patients in European psychiatric hospitals and inpatient units. In this large-scale, multinational projects there are all together six European countries involved: Finland, Ireland, England, Portugal, Italy and Lithuania. The project work plan were during autumn 2006 and spring 2007. The content of this publication was produced in the first stage of the project aiming to collect the preliminary source material for the project. The literature review was carried out in the project stage, providing the groundwork for the next steps for the project. This project aims to develop an interactive multinational portal with training material. Therefore, it is important to share an understanding of basic information, psychiatric nurse’s continuing vocational education, laws and ethical codes and patient restriction used in mental health care. In this publication, the purpose of the material produced here is to understand nurses’ educational need related to vocational continuing education and to be used in further project stages as an empirical data collection. The data were collected as a preliminary source material for latter phases where nurse’s perceptions of the current practice, nurse’s attitudes to mental illness, prevalence of use of seclusion room and existing and desired vocational training provision will be collected in six different European countries. The following organisations are involved in this project: University of Turku, Dublin City University, St. Vincent Hospital, National Council for the Professional Development of Nursing and Midwifery, University of Padova, Klaipeda College - Health Faculty, Klaipeda Psychiatric Hospital, Escola Superior de Enfermagem de Lisboa, Centro Hospitalar Psiquiátrico de Lisboa, Omnia Vocational Institution the Espoo Region, Kellokoski psychiatric hospital, Hyvinkää hospital area, Pirkanmaa Hospital District, Kingston University & St. George’s Medical School and South West London & St. George’s Mental Health NHS Trust. A wide variety of different countries, organisations and individuals in this project give us a strong confidence that theoretical, practical, ethical and political issues around the topic of interest will be taken account during this project lifetime. We are aware the content of this book will be partially outdated almost as soon as it has been published. We still hope that this publication will encourage nurses and different professions working in mental health care field to have a basic understanding of similarities and differences between different European countries related in mental health care. We also hope that this publication will inspirate and motivate nurses in maintaining and developing the quality of psychiatric care in Europe.

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This study analyzed high-density event-related potentials (ERPs) within an electrical neuroimaging framework to provide insights regarding the interaction between multisensory processes and stimulus probabilities. Specifically, we identified the spatiotemporal brain mechanisms by which the proportion of temporally congruent and task-irrelevant auditory information influences stimulus processing during a visual duration discrimination task. The spatial position (top/bottom) of the visual stimulus was indicative of how frequently the visual and auditory stimuli would be congruent in their duration (i.e., context of congruence). Stronger influences of irrelevant sound were observed when contexts associated with a high proportion of auditory-visual congruence repeated and also when contexts associated with a low proportion of congruence switched. Context of congruence and context transition resulted in weaker brain responses at 228 to 257 ms poststimulus to conditions giving rise to larger behavioral cross-modal interactions. Importantly, a control oddball task revealed that both congruent and incongruent audiovisual stimuli triggered equivalent non-linear multisensory interactions when congruence was not a relevant dimension. Collectively, these results are well explained by statistical learning, which links a particular context (here: a spatial location) with a certain level of top-down attentional control that further modulates cross-modal interactions based on whether a particular context repeated or changed. The current findings shed new light on the importance of context-based control over multisensory processing, whose influences multiplex across finer and broader time scales.

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NlmCategory="UNASSIGNED">Alphaproteobacteria include many medically and environmentally important organisms. Despite the diversity of their niches and lifestyles, from free-living to host-associated, they usually rely on very similar mechanisms to control their cell cycles. Studies on Caulobacter crescentus still lay the foundation for understanding the molecular details of pathways regulating DNA replication and cell division and coordinating these two processes with other events of the cell cycle. This review highlights recent discoveries on the regulation and the mode of action of conserved global regulators and small molecules like c-di-GMP and (p)ppGpp, which play key roles in cell cycle control. It also describes several newly identified mechanisms that modulate cell cycle progression in response to stresses or environmental conditions.

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The aim of the work is to study the existing analytical calculation procedures found in literature to calculate the eddy-current losses in surface mounted permanent magnets within PMSM application. The most promising algorithms are implemented with MATLAB software under the dimensional data of LUT prototype machine. In addition finite elements analyze, utilized with help of Flux 2D software from Cedrat Ltd, is applied to calculate the eddy-current losses in permanent magnets. The results obtained from analytical methods are compared with numerical results.

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Hybrid electric vehicles (HEV) have attracted very much attention during the latest years. Increasing environmental concern and an increase in fuel prices are key factors for the growing interest towards the HEV. In a hybrid electric vehicle the power train consists of both a mechanical power system and an electric power transmission system. The major subsystems in the mechanical power system are the internal combustion engine which powers the vehicle; electric power transmission including an energy storage, power electronic inverter, hybrid control system; the electric motor drive that runs either in the generating mode or in the motoring mode to process the power flow between the energy storage and the electrical machine. This research includes two advanced electric motors for a parallel hybrid: induction machine and permanent magnets synchronous machine. In the thesis an induction motor and a permanent magnet motor are compared as propulsion motors. Electric energy storages are also studied.