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Stress i förskolan : Pedagogens möjlighet att se när barn i 2 till 4-årsåldern är stressadeWassberg, Britt-mari January 2008 (has links)
<p>Denna uppsats handlar om samband mellan barn och stress. Stressen finns överallt även bland de yngsta barnen på förskolan. Syftet med min uppsats är att undersöka vilka kunskaper och vilken uppfattningsförmåga pedagogerna i förskolan har om stress. Hur vi som pedagoger kan se att barn är stressade och vilka faktorer som leder till stress hos förskolebarnen i åldrarna 2 till 4 år. Undersökningen är kvalitativ och består av en enkät som delats ut till 40 st pedagoger varav 25 har svarat. Resultatet visar att det är svårt att se alla barnen när det är stora barngrupper och att det är för många aktiviteter under dagen, barnen får ingen tid till återkoppling. För att minska stressen på förskolan så behöver det vara färre barn i barngrupperna, så att pedagogerna hinner se att alla barnen mår bra.</p> / <p>This is an essay about children and stress. Stress is always present even among the youngest children in preschool. The purpose of this essay is to investigate what knowledge and apprehension of stress the educationalists in preschool have. How we as educationalist can see when a child is stressed and what factors that leads to stress for preschool children in the age</p><p>2 – 4. The investigation is qualitative and is made as a questionnaire to 40 educationalists of which 25 answered. The result of the essay shows that it is difficult to observe all children when they are in large groups; it is also difficult when the child group has a lot of activities during the day and there is no time given for feedback to the children. To reduce the stress in preschool, it’s necessary to decrease the amount of children in the groups, so the educationalists can relate to all of the children’s wellness.</p>
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Stress i förskolan : Pedagogens möjlighet att se när barn i 2 till 4-årsåldern är stressadeWassberg, Britt-mari January 2008 (has links)
Denna uppsats handlar om samband mellan barn och stress. Stressen finns överallt även bland de yngsta barnen på förskolan. Syftet med min uppsats är att undersöka vilka kunskaper och vilken uppfattningsförmåga pedagogerna i förskolan har om stress. Hur vi som pedagoger kan se att barn är stressade och vilka faktorer som leder till stress hos förskolebarnen i åldrarna 2 till 4 år. Undersökningen är kvalitativ och består av en enkät som delats ut till 40 st pedagoger varav 25 har svarat. Resultatet visar att det är svårt att se alla barnen när det är stora barngrupper och att det är för många aktiviteter under dagen, barnen får ingen tid till återkoppling. För att minska stressen på förskolan så behöver det vara färre barn i barngrupperna, så att pedagogerna hinner se att alla barnen mår bra. / This is an essay about children and stress. Stress is always present even among the youngest children in preschool. The purpose of this essay is to investigate what knowledge and apprehension of stress the educationalists in preschool have. How we as educationalist can see when a child is stressed and what factors that leads to stress for preschool children in the age 2 – 4. The investigation is qualitative and is made as a questionnaire to 40 educationalists of which 25 answered. The result of the essay shows that it is difficult to observe all children when they are in large groups; it is also difficult when the child group has a lot of activities during the day and there is no time given for feedback to the children. To reduce the stress in preschool, it’s necessary to decrease the amount of children in the groups, so the educationalists can relate to all of the children’s wellness.
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Relativistic Visualizations / Relativistic VisualizationsRingstam, Andreas January 2020 (has links)
Special relativity is an area of physics that is abstract and consists of concepts and effects that is hard to link to everyday experience. From a learning perspective, that is problematic as we form new knowledge by linking it to old experiences. One approach to experience a relativistic environment is through computer simulations. MIT game lab has developed the game “A Slower Speed of Light” where the user slows down the speed of light in discrete steps. That allows the user to experience what the surroundings would look like if we were traveling at a relativistic speed. As the user does that, he/she will experience that certain visual effects do not appear as the course literature describes it. In this project, we study how visual effects of special relativity are perceived by students by letting them play the game and solve an assignment. In the assignment, there was one problem where they were instructed to identify two relativistic effects and describe the physics behind them. The project aims to find an answer to what students while playing the game think they see and how they relate the visual effects to quantities arrived by applying the Lorentz transformation. The project also investigates whether the game can be used productively in teaching. The findings of project show that it is easier for students to describe visual effects where observation match with what the students actually see. We have also found that the students' perception of visual effects is that they are consistent with the predictions of the Lorentz transformation as they try to force their observations onto the theory. That despite the fact that the game clearly shows that it is not the case. The game can be used productively by a teacher when lecturing e.g. relativistic optics. / Speciell relativitetsteori är ett område inom fysiken som är abstrakt och består av begrepp och effekter som är svåra att länka till vardagslivet. Från ett lärandeperspektiv blir det problematiskt då vi bildar ny kunskap genom att länka det till gamla erfarenheter. Ett sätt att få uppleva en relativistisk miljö är genom datorsimuleringar. MIT game lab har utvecklat spelet “A Slower Speed of Light” där användaren stegvis saktar ner ljusets hastighet. Detta gör det möjligt för användaren att uppleva hur omgivningen skulle se ut om vi färdades i en relativistisk hastighet. När användaren färdas relativistiskt kommer han/hon uppleva att vissa visuella effekter inte stämmer överens med beskrivningar från kurslitteratur. I detta projekt studerar vi hur visuella effekter av den speciella relativitetsteorin uppfattas av studenter genom att låta dem spela spelet och lösa en inlämningsuppgift. I inlämningsuppgiften fanns ett problem där de skulle identifiera två relativistiska effekter och beskriva fysiken bakom dessa. Projektet försöker att besvara vilka effekter studenter tror att de ser när de spelar spelet men också hur de relaterar de visuella effekterna till värden som förutsägs genom Lorentz transformationen. Projektet undersöker också om spelet kan användas produktivt i undervisning. Projektets observationer visar att studenterna har lättare att beskriva visuella effekter där observation stämmer överens med vad studenterna faktiskt ser. Vi har ocksånoterat att studenternas föreställning om visuella effekter är att de stämmer överens med Lorentztransformationens förutsägelser då de försöker tvinga sina observationer att överensstämma med teorin trots att spelet tydligt visar att det inte är fallet. Spelet kan användas produktivt av en lärare vid föreläsning av t.ex. relativistisk optik.
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Estudo Comparativo de Controladores Fuzzy Aplicados a um Sistema Solar Fotovoltaico. / Comparative study of fuzzy controller applied to a solar photovoltaic system.Carlos Antônio Pereira Tavares 05 August 2009 (has links)
Neste trabalho apresenta-se o modelo de um controlador baseado em Lógica Fuzzy para um sistema de energia baseado em fonte renovável solar fotovoltaica (photovoltaic - PV) multi-string em operação isolada, para o aproveitamento da máxima potência desta fonte. O sistema é composto por painéis solares, conversor CC-CC tipo elevador de tensão (boost), armazenamento por banco de baterias, inversor trifásico e carga trifásica variável. O sistema fotovoltaico foi modelado no MATLAB/Simulink de forma a representar a curva característica V-I do módulo PV, e que é baseado nos dados disponíveis em data-sheets de painéis fotovoltaicos comerciais. Outros estudos de natureza elétrica tais como o cálculo dos valores eficazes das correntes no conversor CC-CC, para avaliação das perdas, indispensáveis para o dimensionamento de componentes eletrônicos, foram realizados. O método tradicional Perturb and Observe de rastreamento do ponto de máxima potência (Maximum Power Point Tracking MPPT) de painéis foi testado e comparado com métodos que usam a Lógica Fuzzy. Devido ao seu desempenho, foi adotado o método Fuzzy que realiza o MPPT por inferência do ciclo de trabalho de um modulador por largura de pulso (Pulse Width Modulation - PWM) através da variação da potência pela variação da corrente do painel solar. O modelo Fuzzy adotado neste trabalho foi testado com sucesso. Os resultados mostraram que ele pode ser robusto e atende à aplicação proposta. Segundo alguns testes realizados, este controlador pode realizar o MPPT de um sistema PV na configuração multi-string onde alguns arranjos fotovoltaicos são usados. Inclusive, este controle pode ser facilmente adaptado para realizar o MPPT de outras fontes de energia baseados no mesmo princípio de controle, como é o caso do aerogerador. / This work presents the model of a Fuzzy Logic controller for a renewable energy system based on multi-string solar photovoltaic (PV) in stand-alone operation, to extract the maximum energy of this power source. The system consists of PV modules, DC-DC converter (Boost), a battery set, three-phase inverter and three-phase variable load. The photovoltaic system was modeled in MATLAB / Simulink in order to represent the V-I characteristic of the PV module, and which is based on the data provided by the manufacturer data-sheet. Other studies, such as the calculation of the RMS currents of the DC-DC converter components for evaluation of the losses, which are essential for the system design were accomplished. The conventional Perturb and Observe method for the Maximum Power Point Tracking (MPPT) of PV modules was tested and compared with methods that use Fuzzy Logic control. Due to its performance, it was adopted the Fuzzy method that performs the MPPT by inference of duty cycle of a Pulse Width Modulation (PWM) through the variation of PV power divided by the variation of the PV current. The Fuzzy model considered in this work was successfully tested. The results showed that it can be robust and suitable to the proposed application. According to some accomplished tests, the controller can perform the MPPT of a multi-string configuration of the solar PV system, in which several PV arrays are used. Moreover, it can also be easily adapted to perform the MPPT of other energy power sources based on the same control principle, as it is in the case of aerogenerators.
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Estudo Comparativo de Controladores Fuzzy Aplicados a um Sistema Solar Fotovoltaico. / Comparative study of fuzzy controller applied to a solar photovoltaic system.Carlos Antônio Pereira Tavares 05 August 2009 (has links)
Neste trabalho apresenta-se o modelo de um controlador baseado em Lógica Fuzzy para um sistema de energia baseado em fonte renovável solar fotovoltaica (photovoltaic - PV) multi-string em operação isolada, para o aproveitamento da máxima potência desta fonte. O sistema é composto por painéis solares, conversor CC-CC tipo elevador de tensão (boost), armazenamento por banco de baterias, inversor trifásico e carga trifásica variável. O sistema fotovoltaico foi modelado no MATLAB/Simulink de forma a representar a curva característica V-I do módulo PV, e que é baseado nos dados disponíveis em data-sheets de painéis fotovoltaicos comerciais. Outros estudos de natureza elétrica tais como o cálculo dos valores eficazes das correntes no conversor CC-CC, para avaliação das perdas, indispensáveis para o dimensionamento de componentes eletrônicos, foram realizados. O método tradicional Perturb and Observe de rastreamento do ponto de máxima potência (Maximum Power Point Tracking MPPT) de painéis foi testado e comparado com métodos que usam a Lógica Fuzzy. Devido ao seu desempenho, foi adotado o método Fuzzy que realiza o MPPT por inferência do ciclo de trabalho de um modulador por largura de pulso (Pulse Width Modulation - PWM) através da variação da potência pela variação da corrente do painel solar. O modelo Fuzzy adotado neste trabalho foi testado com sucesso. Os resultados mostraram que ele pode ser robusto e atende à aplicação proposta. Segundo alguns testes realizados, este controlador pode realizar o MPPT de um sistema PV na configuração multi-string onde alguns arranjos fotovoltaicos são usados. Inclusive, este controle pode ser facilmente adaptado para realizar o MPPT de outras fontes de energia baseados no mesmo princípio de controle, como é o caso do aerogerador. / This work presents the model of a Fuzzy Logic controller for a renewable energy system based on multi-string solar photovoltaic (PV) in stand-alone operation, to extract the maximum energy of this power source. The system consists of PV modules, DC-DC converter (Boost), a battery set, three-phase inverter and three-phase variable load. The photovoltaic system was modeled in MATLAB / Simulink in order to represent the V-I characteristic of the PV module, and which is based on the data provided by the manufacturer data-sheet. Other studies, such as the calculation of the RMS currents of the DC-DC converter components for evaluation of the losses, which are essential for the system design were accomplished. The conventional Perturb and Observe method for the Maximum Power Point Tracking (MPPT) of PV modules was tested and compared with methods that use Fuzzy Logic control. Due to its performance, it was adopted the Fuzzy method that performs the MPPT by inference of duty cycle of a Pulse Width Modulation (PWM) through the variation of PV power divided by the variation of the PV current. The Fuzzy model considered in this work was successfully tested. The results showed that it can be robust and suitable to the proposed application. According to some accomplished tests, the controller can perform the MPPT of a multi-string configuration of the solar PV system, in which several PV arrays are used. Moreover, it can also be easily adapted to perform the MPPT of other energy power sources based on the same control principle, as it is in the case of aerogenerators.
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Företagsetik : En studie av etiskt organiserande i några svenska företag / Business ethics : A study of ethical organizing in some Swedish companiesBeckius, Göran January 2006 (has links)
<p>Although research in business ethics has of late received increased attention from researchers and practitioners, little has been written on the practical effects of its implementation.</p><p>The aim of the present study is, therefore, to explore the meaning and implications of business ethics from a practical perspective. To these ends, a qualitative study, mainly based on a grounded theory approach, has been carried out. The target of analysis is a corpus material derived from informants from 9 companies ranging from different sectors: 2 from the manufacturing sector, 1 company from the pharmaceutical sector and 6 companies from the financial sector.</p><p>The results show that almost all the companies under consideration have set up some ethical structures for implementing their ethical practices, and lived up to the embraced ethical values in their business conduct. The results also indicate that the companies have actually responded favorably to the requirements and demands of various stakeholders.</p><p>Furthermore, the emerging structures constitute the basis of a fully operative concept for organizing and implementing an ethical business conduct in organizations. This concept mainly consists of the following categories: ethics, rules, institutionalization, observing and abiding. These can all be applied separately or as a whole and as such be an instrument for measuring an organizations ethical level.</p><p> </p>
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Företagsetik : En studie av etiskt organiserande i några svenska företag / Business ethics : A study of ethical organizing in some Swedish companiesBeckius, Göran January 2006 (has links)
Although research in business ethics has of late received increased attention from researchers and practitioners, little has been written on the practical effects of its implementation. The aim of the present study is, therefore, to explore the meaning and implications of business ethics from a practical perspective. To these ends, a qualitative study, mainly based on a grounded theory approach, has been carried out. The target of analysis is a corpus material derived from informants from 9 companies ranging from different sectors: 2 from the manufacturing sector, 1 company from the pharmaceutical sector and 6 companies from the financial sector. The results show that almost all the companies under consideration have set up some ethical structures for implementing their ethical practices, and lived up to the embraced ethical values in their business conduct. The results also indicate that the companies have actually responded favorably to the requirements and demands of various stakeholders. Furthermore, the emerging structures constitute the basis of a fully operative concept for organizing and implementing an ethical business conduct in organizations. This concept mainly consists of the following categories: ethics, rules, institutionalization, observing and abiding. These can all be applied separately or as a whole and as such be an instrument for measuring an organizations ethical level.
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Potential of existing UMTS Signaling Data for Cell Phone PositioningAkram, Awais, Ahmad, Hamad January 2011 (has links)
In the current era of telecommunication the usage of cellular network has increased rapidly. Number of different new services are introduced i.e. navigation, friend finder, internet browsing, nearby filling stations, shopping centers, traffic information and emergency services. Most of these services are location based and needs the information of particular area to provide the exact services. The addition of location based services in 3G network opens the new ways of using Mobile devices due to which cellular networks has faced number of challenges in providing better positioning accuracy which is the main requirement for location based services. To bear these challenges everyday new ways of finding the accurate position are introduced but most them required upgraded networks or highly equipped terminal. In this thesis the purpose is to find the potential in UMTS signaling data to estimate the position of the user equipment as accurate as possible using the legacy terminals. In this thesis SFN-SFN observed time difference is explored and used in Database Correlation Method (DCM) in network based positioning. This thesis is done by first analyzing the RSCP for the particular area to verify the conditions of FCC. The data is collected in real environment through test drive using TEMS investigation tool and the available measurement reports from the terminal are used to design and implement the DCM Algorithm. Two new approaches are introduced in this thesis SFN-SFN OTD and Hybrid. In Hybrid RSCP and SFN-SFN OTD are used together. In conclusion, the final results from the performed experiments show improvement in estimated position accuracy by Hybrid technique which is a new step in finding the position of user equipment by DCM.
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Fpga-based Design Of A Maximum-power-point Tracking System For Space APersen, Todd 01 January 2004 (has links)
Satellites need a source of power throughout their missions to help them remain operational for several years. The power supplies of these satellites, provided primarily by solar arrays, must have high efficiencies and low weights in order to meet stringent design constraints. Power conversion from these arrays is required to provide robust and reliable conversion which performs optimally in varying conditions of peak power, solar flux, and occlusion conditions. Since the role of these arrays is to deliver power, one of the principle factors in achieving maximum power output from an array is tracking and holding its maximum-power point. This point, which varies with temperature, insolation, and loading conditions, must be continuously monitored in order to react to rapid changes. Until recently, the control of maximum power point tracking (MPPT) has been implemented in microcontrollers and digital signal processors (DSPs). While DSPs can provide a reasonable performance, they do not provide the advantages that field-programmable gate arrays (FPGA) chips can potentially offer to the implementation of MPPT control. In comparison to DSP implementations, FPGAs offer lower cost implementations since the functions of various components can be integrated onto the same FPGA chip as opposed to DSPs which can perform only DSP-related computations. In addition, FPGAs can provide equivalent or higher performance with the customization potential of an ASIC. Because FPGAs can be reprogrammed at any time, repairs can be performed in-situ while the system is running thus providing a high degree of robustness. Beside robustness, this reprogrammability can provide a high level of (i) flexibility that can make upgrading an MPPT control system easy by merely updating or modifying the MPPT algorithm running on the FPGA chip, and (ii) expandability that makes expanding an FPGA-based MPPT control system to handle multi-channel control. In addition, this reprogrammability provides a level of testability that DSPs cannot match by allowing the emulation of the entire MPPT control system onto the FPGA chip. This thesis proposes an FPGA-based implementation of an MPPT control system suitable for space applications. At the core of this system, the Perturb-and-observe algorithm is used to track the maximum power point. The algorithm runs on an Alera FLEX 10K FPGA chip. Additional functional blocks, such as the ADC interface, FIR filter, dither generator, and DAC interface, needed to support the MPPT control system are integrated within the same FPGA device thus streamlining the part composition of the physical prototype used to build this control system.
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Observateurs grand gain pour des systèmes non linéaires à sorties échantillonnées et retardées / High gain observers for nonlinear systems with sampled and delayed outputsTreangle, Clement 04 December 2018 (has links)
Ce manuscrit porte sur la synthèse d'observateurs grand gain pour des systèmes non linéaires à sorties échantillonnées et retardées. Trois contributions sont proposées à la lecture de ce manuscrit. La première contribution, pour une classe de systèmes Multi-entrées / Multi-sorties uniformément observables et dont les sorties sont regroupées en un seul bloc, met en jeu le problème du processus d'acquisition des mesures de sorties (continues, échantillonnées, retardées ou non) et propose un cadre commun pour l'ensemble des cas possibles. La deuxième contribution propose un observateur grand gain filtré sur cette même classe de systèmes dans l'optique de réduire la sensibilité au bruit de mesure, dans le cas où la sortie est continue puis dans le cas où cette dernière est échantillonnée. La dernière contribution vise à étendre la synthèse grand gain standard pour une large classe de systèmes Multi-entrées / Multi-sorties uniformément observables dont les mesures des sorties sont continues. Pour chacune de ces contributions, il a été montré que l'erreur d'observation de chacun des observateurs proposés converge exponentiellement vers zéro en l'absence d'incertitudes sur le système. Toutes ces contributions ont été illustrées par différents exemples issus de plusieurs domaines d'étude. / This manuscript deals with the synthesis of high gain observers for nonlinear systems with sampled and delayed outputs. Three contributions are proposed for consideration in this manuscript. The first contribution, for a class of Multi-input / Multi-output systems whose outputs are grouped into a single block, involves the problem of the acquisition process of output measurements (continuous, sampled, delayed or not) and proposes a common framework for all possible cases. The second contribution proposes a filtered high gain observer on this same class of systems in order to reduce the sensitivity to measurement noise, in the case where the output is continuous and then in the case where the latter is sampled. The last contribution aims to extend the standard high gain synthesis for a large class of uniformly observable Multi-input / Multi-output systems with continuous output measurements. For each of these contributions, it has been shown that the observation error of each of the proposed observers converges exponentially towards zero in the absence of uncertainties in the system. All these contributions have been illustrated through several examples from different fields of study.
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