Broadband excitation in the system identification of active magnetic bearing rotor systems

One of the targets of the climate and energy package of the European Union is to increase the energy efficiency in order to achieve a 20 percent reduction in primary energy use compared with the projected level by 2020. The energy efficiency can be improved for example by increasing the rotational speed of large electrical drives, because this enables the elimination of gearboxes leading to a compact design with lower losses. The rotational speeds of traditional bearings, such as roller bearings, are limited by mechanical friction. Active magnetic bearings (AMBs), on the other hand, allow very high rotational speeds. Consequently, their use in large medium- and high-speed machines has rapidly increased. An active magnetic bearing rotor system is an inherently unstable, nonlinear multiple-input, multiple-output system. Model-based controller design of AMBs requires an accurate system model. Finite element modeling (FEM) together with the experimental modal analysis provides a very accurate model for the rotor, and a linearized model of the magneticactuators has proven to work well in normal conditions. However, the overall system may suffer from unmodeled dynamics, such as dynamics of foundation or shrink fits. This dynamics can be modeled by system identification. System identification can also be used for on-line diagnostics. In this study, broadband excitation signals are adopted to the identification of an active magnetic bearing rotor system. The broadband excitation enables faster frequency response function measurements when compared with the widely used stepped sine and swept sine excitations. Different broadband excitations are reviewed, and the random phase multisine excitation is chosen for further study. The measurement times using the multisine excitation and the stepped sine excitation are compared. An excitation signal design with an analysis of the harmonics produced by the nonlinear system is presented. The suitability of different frequency response function estimators for an AMB rotor system are also compared. Additionally, analytical modeling of an AMB rotor system, obtaining a parametric model from the nonparametric frequency response functions, and model updating are discussed in brief, as they are key elements in the modeling for a control design. Theoretical methods are tested with a laboratory test rig. The results conclude that an appropriately designed random phase multisine excitation is suitable for the identification of AMB rotor systems.

Analogisten erotusvahvistimien nykytilan kartoitus

Erotusvahvistin on instrumentointivahvistin, jonka tulo ja lähtö ovat galvaanisesti erotettu toisistaan. Erotusvahvistimia käytetään galvaanista erotusta vaativissa sovelluksissa, muun muassa sairaalalaitteissa. Teollisuudessa on olemassa sovelluksia, joihin tarvittaisiin analogisia erotusvahvistimia, mutta ei tiedetä onko analogisilla erotusvahvistimilla riittävän hyvät komponenttiarvot. Tässä työssä selvitetään analogisten erotusvahvistimien tämänhetkisiä ominaisuuksia, hintoja ja komponenttiarvoja neljältä eri valmistajalta.

Energetic efficiency of a deep bed swine production system

The aim of this work was to evaluate the energy flows of a commercial production system of swine deep bed in its finishing phase, located in Juiz de Fora, in the State of Minas Gerais, Brazil. Thus, an energy efficiency study was carried out by monitoring a lot of animals, during a 94-day period. The energy rate of each compound involved in the production process was quantified and the matrixes of energy consumption were determined in the form of animal feeding, electrical energy, piglets, material used as deep bed, human labor, equipment, swine buildings, production of alive swine for slaughter, organic fertilizer production (swine deep bed or swine deep litter). From the direct input energy, 80.57% correspond to animal feeding, 11.90% to pigs for slaughter and 6.76% to piglets, while from the energy output 53.45% correspond to the terminating swine and 46.55% to organic fertilizer (swine deep bed). By the results obtained, we can conclude that such production system has corresponded to an industrial and highly specialized agro ecosystem, importing a great part of the energy consumed in the production process, with 41% of energy efficiency.

Tuoteideoiden ja niiden innovaatiopotentiaalin arviointi pääomasijoittajan näkökulmasta

Tässä tutkimuksessa selvitetään, miten pääomasijoittajat arvioivat tuoteideoita sekä niiden potentiaalisuutta kehittyä innovaatioiksi. Tutkimusongelmaa lähestytään kolmen osaongelman kautta: 1. Millaisia prosesseja, menetelmiä tai käytäntöjä pääomasijoittajilla on tuoteideoiden arviointiin; 2. Millaisia innovaation tekijöitä, komponentteja tai attribuutteja pääomasijoittajat huomioivat tuoteideaa arvioidessaan; 3. Millaisia tekijöitä pääomasijoittajat huomioivat tuoteidean innovaatiopotentiaalin arvioinnissa, ja kuinka tärkeitä nämä tekijät ovat. Tutkimusongelman selvittämiseksi ja ymmärtämiseksi kuvataan innovaatio -käsite: mitä on innovaatiotoiminta, millainen on innovaatioprosessi ja miten ideasta edetään kohti tuotetta ja mahdollista innovaatiota. Potentiaalisten ideoiden rahoitusta tarkastellaan sekä yleisellä tasolla että pääomasijoittajien näkökulmasta. Pääomasijoittamisen historia, sijoitusmotiivit sekä pääomasijoitusprosessi selvitetään. Lisäksi selvitetään tuoteinnovaation tekijät, jotka tässä tutkimuksessa ovat syötteet, prosessit ja tuotokset. Tutkimukseen liittyvä tiedonkeruu suoritettiin verkkokyselynä keväällä 2013. Tutkimus oli kokonaistutkimus, ja kyselylomake lähetettiin kaikille FVCA:n jäsenille (Suomen pääomasijoi-tusyhdistys ry:n varsinaiset jäsenet). Empiirisessä osiossa selvitettiin pääomasijoittajien taus-tatietojen lisäksi tuoteidean arviointiin liittyviä menetelmiä ja järjestelmiä, syötteitä, prosesseja, tuotoksia sekä tuoteidean innovaatiopotentiaaliin liittyviä asioita. Pääomasijoittajia kiinnostaa eniten yritysten kasvuvaiheen rahoitus ja toimialoista teollisuus sekä energia. Tuoteideoita ja niiden innovaatiopotentiaalia arvioidaan useiden eri tekijöiden perusteella, mutta vakiintuneita ja kiinteitä arviointimenetelmiä tai -prosesseja on harvalla yrityksistä.

Energy and raw material consumption analysis of powder bed fusion: case study: CNC machining and laser additive manufacturing

Laser additive manufacturing (LAM), known also as 3D printing, is a powder bed fusion (PBF) type of additive manufacturing (AM) technology used to manufacture metal parts layer by layer by assist of laser beam. The development of the technology from building just prototype parts to functional parts is due to design flexibility. And also possibility to manufacture tailored and optimised components in terms of performance and strength to weight ratio of final parts. The study of energy and raw material consumption in LAM is essential as it might facilitate the adoption and usage of the technique in manufacturing industries. The objective this thesis was find the impact of LAM on environmental and economic aspects and to conduct life cycle inventory of CNC machining and LAM in terms of energy and raw material consumption at production phases. Literature overview in this thesis include sustainability issues in manufacturing industries with focus on environmental and economic aspects. Also life cycle assessment and its applicability in manufacturing industry were studied. UPLCI-CO2PE! Initiative was identified as mostly applied exiting methodology to conduct LCI analysis in discrete manufacturing process like LAM. Many of the reviewed literature had focused to PBF of polymeric material and only few had considered metallic materials. The studies that had included metallic materials had only measured input and output energy or materials of the process and compared to different AM systems without comparing to any competitive process. Neither did any include effect of process variation when building metallic parts with LAM. Experimental testing were carried out to make dissimilar samples with CNC machining and LAM in this thesis. Test samples were designed to include part complexity and weight reductions. PUMA 2500Y lathe machine was used in the CNC machining whereas a modified research machine representing EOSINT M-series was used for the LAM. The raw material used for making the test pieces were stainless steel 316L bar (CNC machined parts) and stainless steel 316L powder (LAM built parts). An analysis of power, time, and the energy consumed in each of the manufacturing processes on production phase showed that LAM utilises more energy than CNC machining. The high energy consumption was as result of duration of production. Energy consumption profiles in CNC machining showed fluctuations with high and low power ranges. LAM energy usage within specific mode (standby, heating, process, sawing) remained relatively constant through the production. CNC machining was limited in terms of manufacturing freedom as it was not possible to manufacture all the designed sample by machining. And the one which was possible was aided with large amount of material removed as waste. Planning phase in LAM was shorter than in CNC machining as the latter required many preparation steps. Specific energy consumption (SEC) were estimated in LAM based on the practical results and assumed platform utilisation. The estimated platform utilisation showed SEC could reduce when more parts were placed in one build than it was in with the empirical results in this thesis (six parts).

Modular Double-Cascade Converter

Medium-voltage motor drives extend the power rating of AC motor drives in industrial applications. Multilevel converters are gaining an ever-stronger foothold in this field. This doctoral dissertation introduces a new topology to the family of modular multilevel converters: the modular double-cascade converter. The modularity of the converter is enabled by the application of multiwinding mediumfrequency isolation transformers. Owing to the innovative transformer link, the converter presents many advantageous properties at a concept level: modularity, high input and output power quality, small footprint, and wide variety of applications, among others. Further, the research demonstrates that the transformer link also plays a key role in the disadvantages of the topology. An extensive simulation study on the new converter is performed. The focus of the simulation study is on the development of control algorithms and the feasibility of the topology. In particular, the circuit and control concepts used in the grid interface, the coupling configurations of the load inverter, and the transformer link operation are thoroughly investigated. Experimental results provide proof-of-concept results on the operation principle of the converter. This work concludes a research collaboration project on multilevel converters between LUT and Vacon Plc. The project was active from 2009 until 2014.

Striatal and extrastriatal dopamine D2/3 receptors studied with [11C]raclopride and high-resolution PET

The human striatum is a heterogeneous structure representing a major part of the dopamine (DA) system’s basal ganglia input and output. Positron emission tomography (PET) is a powerful tool for imaging DA neurotransmission. However, PET measurements suffer from bias caused by the low spatial resolution, especially when imaging small, D2/3 -rich structures such as the ventral striatum (VST). The brain dedicated high-resolution PET scanner, ECAT HRRT (Siemens Medical Solutions, Knoxville, TN, USA) has superior resolution capabilities than its predecessors. In the quantification of striatal D2/3 binding, the in vivo highly selective D2/3 antagonist [11C] raclopride is recognized as a well-validated tracer. The aim of this thesis was to use a traditional test-retest setting to evaluate the feasibility of utilizing the HRRT scanner for exploring not only small brain regions such as the VST but also low density D2/3 areas such as cortex. It was demonstrated that the measurement of striatal D2/3 binding was very reliable, even when studying small brain structures or prolonging the scanning interval. Furthermore, the cortical test-retest parameters displayed good to moderate reproducibility. For the first time in vivo, it was revealed that there are significant divergent rostrocaudal gradients of [11C]raclopride binding in striatal subregions. These results indicate that high-resolution [11C]raclopride PET is very reliable and its improved sensitivity means that it should be possible to detect the often very subtle changes occurring in DA transmission. Another major advantage is the possibility to measure simultaneously striatal and cortical areas. The divergent gradients of D2/3 binding may have functional significance and the average distribution binding could serve as the basis for a future database. Key words: dopamine, PET, HRRT, [11C]raclopride, striatum, VST, gradients, test-retest.

AnaBench: a Web/CORBA-based workbench for biomolecular sequence analysis

Affiliation: Département de biochimie, Faculté de médecine, Université de Montréal

The use of artificial intelligence algorithms to guide surgical treatment of adolescent idiopathic scoliosis

La scoliose idiopathique de l’adolescent (SIA) est une déformation tri-dimensionelle du rachis. Son traitement comprend l’observation, l’utilisation de corsets pour limiter sa progression ou la chirurgie pour corriger la déformation squelettique et cesser sa progression. Le traitement chirurgical reste controversé au niveau des indications, mais aussi de la chirurgie à entreprendre. Malgré la présence de classifications pour guider le traitement de la SIA, une variabilité dans la stratégie opératoire intra et inter-observateur a été décrite dans la littérature. Cette variabilité s’accentue d’autant plus avec l’évolution des techniques chirurgicales et de l’instrumentation disponible. L’avancement de la technologie et son intégration dans le milieu médical a mené à l’utilisation d’algorithmes d’intelligence artificielle informatiques pour aider la classification et l’évaluation tridimensionnelle de la scoliose. Certains algorithmes ont démontré être efficace pour diminuer la variabilité dans la classification de la scoliose et pour guider le traitement. L’objectif général de cette thèse est de développer une application utilisant des outils d’intelligence artificielle pour intégrer les données d’un nouveau patient et les évidences disponibles dans la littérature pour guider le traitement chirurgical de la SIA. Pour cela une revue de la littérature sur les applications existantes dans l’évaluation de la SIA fut entreprise pour rassembler les éléments qui permettraient la mise en place d’une application efficace et acceptée dans le milieu clinique. Cette revue de la littérature nous a permis de réaliser que l’existence de “black box” dans les applications développées est une limitation pour l’intégration clinique ou la justification basée sur les évidence est essentielle. Dans une première étude nous avons développé un arbre décisionnel de classification de la scoliose idiopathique basé sur la classification de Lenke qui est la plus communément utilisée de nos jours mais a été critiquée pour sa complexité et la variabilité inter et intra-observateur. Cet arbre décisionnel a démontré qu’il permet d’augmenter la précision de classification proportionnellement au temps passé à classifier et ce indépendamment du niveau de connaissance sur la SIA. Dans une deuxième étude, un algorithme de stratégies chirurgicales basé sur des règles extraites de la littérature a été développé pour guider les chirurgiens dans la sélection de l’approche et les niveaux de fusion pour la SIA. Lorsque cet algorithme est appliqué à une large base de donnée de 1556 cas de SIA, il est capable de proposer une stratégie opératoire similaire à celle d’un chirurgien expert dans prêt de 70% des cas. Cette étude a confirmé la possibilité d’extraire des stratégies opératoires valides à l’aide d’un arbre décisionnel utilisant des règles extraites de la littérature. Dans une troisième étude, la classification de 1776 patients avec la SIA à l’aide d’une carte de Kohonen, un type de réseaux de neurone a permis de démontrer qu’il existe des scoliose typiques (scoliose à courbes uniques ou double thoracique) pour lesquelles la variabilité dans le traitement chirurgical varie peu des recommandations par la classification de Lenke tandis que les scolioses a courbes multiples ou tangentielles à deux groupes de courbes typiques étaient celles avec le plus de variation dans la stratégie opératoire. Finalement, une plateforme logicielle a été développée intégrant chacune des études ci-dessus. Cette interface logicielle permet l’entrée de données radiologiques pour un patient scoliotique, classifie la SIA à l’aide de l’arbre décisionnel de classification et suggère une approche chirurgicale basée sur l’arbre décisionnel de stratégies opératoires. Une analyse de la correction post-opératoire obtenue démontre une tendance, bien que non-statistiquement significative, à une meilleure balance chez les patients opérés suivant la stratégie recommandée par la plateforme logicielle que ceux aillant un traitement différent. Les études exposées dans cette thèse soulignent que l’utilisation d’algorithmes d’intelligence artificielle dans la classification et l’élaboration de stratégies opératoires de la SIA peuvent être intégrées dans une plateforme logicielle et pourraient assister les chirurgiens dans leur planification préopératoire.

Web Service Composition Systems for the Web Service Challenge - A Detailed Review

This report gives a detailed discussion on the system, algorithms, and techniques that we have applied in order to solve the Web Service Challenges (WSC) of the years 2006 and 2007. These international contests are focused on semantic web service composition. In each challenge of the contests, a repository of web services is given. The input and output parameters of the services in the repository are annotated with semantic concepts. A query to a semantic composition engine contains a set of available input concepts and a set of wanted output concepts. In order to employ an offered service for a requested role, the concepts of the input parameters of the offered operations must be more general than requested (contravariance). In contrast, the concepts of the output parameters of the offered service must be more specific than requested (covariance). The engine should respond to a query by providing a valid composition as fast as possible. We discuss three different methods for web service composition: an uninformed search in form of an IDDFS algorithm, a greedy informed search based on heuristic functions, and a multi-objective genetic algorithm.

Management practices and challenges in smallholder indigenous chicken production in Western Kenya

The potential benefit of indigenous chicken (Gallus domesticus) production is still under-exploited in Kenya despite the efforts by different stakeholders to mainstream this production system as a pathway to rural development. The production system is often characterized by low input-low output productivity and low commercialization of the enterprise. This study which dwells on the current management practices and challenges faced by smallholder indigenous chicken farmers was conducted to gain insights into the underlying causes of production constraints. In Western Kenya women (76%) dominate the indigenous chicken production system. The flock composition consists mainly of chicks, hens and pullets (80%) which reflects their retention for production purposes. Less than half of the farmers access institutional support services such as extension, training, credit and veterinary services. In addition, indigenous chicken is largely reared in a low input-low output free-range system with only few farmers (24.2%) adopting management interventions as disseminated by extension service. To improve production and attain increased productivity, policy should focus on repackaging extension messages that considers farmers economic situations and strengthens collective action initiatives. Accessing joint input purchase and collective marketing of chicken products may further assist the farmers to increase profit margins.

Proyecto de modificabilidad cognitiva y de enriquecimiento instrumental.

Proyecto de modificabilidad cognitiva y enriquecimiento instrumental (P.E.I.) basado en la teoría de la modificabilidad cognitiva de Reuven Feuerstein, producto de experiencias específicas de aprendizaje mediado E.A.M., cuyo objetivo general es aumentar la capacidad del organismo humano para ser modificado a través de la exposición directa a los estímulos y a la experiencia proporcionada por los contactos con la vida y con las aportaciones del aprendizaje formal e informal. Especificamente se propone corregir las funciones deficientes características que aparecen a lo largo del acto mental en sus tres fases (input, modificación, output), adquirir conceptos básicos, vocabulario y operaciones, desarrollar la motivación intrínseca, crear un cierto nivel de pensamiento reflexivo o insight y desarrollar y fomentar la autopercepción del individuo. El material se presenta como unidades estructuradas o instrumentos cada uno de los cuales pone énfasis en una función cognitiva particular y cuyo contenido se considera secundario respecto al objetivo principal que es la adquisición de los requisitos del pensamiento. Previamente el P.E.I. se presentó al claustro de profesores, a los padres y madres y a los alumnos para así ampliar su difusión a las diferentes áreas, a la vida, al trabajo, etc. La evaluación en P.E.I. se desarrolla a partir de los datos recogidos en: 1. Tests a principio y final del programa que nos ofrecen la conclusión, en general, de: (caras) buena atención en general, (dominó) buena y normal capacidad de discurrir y constancia en el esfuerzo en el 50 por ciento y el resto baja, (Raven) buen o normal razonamiento lógico, (Cattell) aproximadamente nivel de inteligencia bueno 59 por ciento, normal 18 y bajo 23 y (frases), capacidad de conocimiento del lenguaje y organización del pensamiento, normal o buena en un 50 por ciento y baja en el resto. 2. Encuesta anual de evaluación de las clases de P.E.I. por parte de los alumnos que mostraban un aumento de la confianza en sí mismos y sus capacidades, dominio de su impulsividad pensando antes de actuar, ampliación de su vocabulario, mejora en sus niveles de atención, un desarrollo, cambio y adquisición de estrategias ante diferentes tareas, de errores, ... 3. Prueba de evaluación y autoevaluación al finalizar cada instrumento. 4. Encuesta al final del programa sobre la opinión de este por los padres, para una evaluación más completa. 5. Encuesta a los profesores sobre los aspectos que consideran han mejorado con este proyecto. 6. Ficha de seguimiento de cada alumno la cual ofrece una visión clara de la situación de cada alumno y de su evolución durante el proceso observando sus comportamientos, la realización de las tareas, utilización de las funciones y operaciones mentales, de sus dificultades.

Cambridge IGCSE ICT Coursebook.

Este libro ha sido escrito específicamente para el Cambridge IGCSE en la asignatura de enseñanza secundaria ICT (tecnologías de la información y comunicación). El libro y el CD-ROM han sido escritos por profesores con experiencia asegurando que los datos cubran los recientes desarrollos en ICT y sus efectos en nuestras vidas. Los temas del libro son: tipos y componentes de sistemas de ordenador, dispositivos Input y Output, los dispositivos de almacenamiento, redes de ordenador, tipos de datos, los efectos de usar las tecnologías de la información, como las tecnologías son usadas en la vida diaria, las aplicaciones y sus efectos, sistemas de análisis y diseño.

Una evaluación de la equidad del Sistema Educativo español.

Resumen tomado del autor. Este artículo se incluye en el monográfico ïReflexiones sobre política educativaï

???Mi vida loca??? : ejemplo de explotaci??n did??ctica y reflexiones en torno a su integraci??n en ELE

Resumen basado en el de la publicaci??n