Thesis (doctoral)--Friedrich-Wilhelms-Universität zu Berlin, 1933. / Twi text with German translation and notes. Vita. Includes bibliographical references.

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In the electronic industrials, power control of AC motors is commonly used. For example power control of a washing machine motor, a vacuum cleaner motor or a coffee machine motor. The company Rejlers Ingenjörer AB has many projects where power control of AC motors is included. A prototype card for this task can save time and money for the company in the future and this is the reason for this thesis. The motors are power controlled by a TRIAC and control of the trigging pulses to the TRIAC. This card is modularly built and can easily be adapted for future projects where the power control of AC motors are included. The prototype card can be used as a subsystem in a larger electronics projects or as it is in lab environment for testing and evaluating new motors. / Inom elektronikbranschen, exempelvis vitvarutillverkare är effektstyrning av ACmotorer vanligt förekommande. Det kan handla om effektstyrning av en diskmaskinsmotor, en dammsugarmotor eller en tvättmaskinsmotor. Företaget Rejlers ingenjörer AB har flera gånger fått uppdrag där effektstyrning av AC-motorer ingått och har behov av ett prototypkort för detta som ska kunna återanvändas i framtida projekt för att spara tid och pengar. Effektstyrningen av motorerna sker med hjälp av en triac och styrning av tändpulserna till denna triac. Detta kort är modulärt uppbyggd så att det enkelt kan anpassas till framtida projekt där effektstyrning av AC-motorer ingår. Prototypkortet kan användas som ett delsystem i ett större elektronikprojekt eller i labbmiljö för test och utvärdering av nya motorer.

In August 2013 the Norrala tunnel just north of Söderhamn was flooded, which caused a train stuck in thetunnel. In the future the intensity and the amount of rainfall are expected to increase in this area, which canlead to an increased risk of flooding. The purpose of this study was to use GIS to investigate whether it is possible to identify which railroadtunnels that are exposed to flooding during heavy rainfall. In order to investigate this, a GIS analysis wasperformed on the Norrala tunnel. The data used for this study was the National Elevation Model. The result of the study contains maps representing the catchment area for the tunnels and wetness index forthe north and the middle rescue tunnel. The flood analysis shows that the rescue tunnel that was flooded in August 2013 has a catchment area of1,1km², which is 20 times as big as the catchment area for any of the other tunnel entrances. The studyshows that GIS is a great tool for flood mapping. With the chosen method in combination with theNational Elevation Model, it is possible to identify tunnels that are exposed to flooding. The field study that was performed shows that the Swedish property map has flaws concerning hydrology.More than 90% of the water that ended up in the tunnel came from the west side of the highway E4,through a passage for wildlife. After the tunnel, the water was initially directed through a manmade streamthat follows the route of the property map. Further down, the manmade stream disappears and the waterthen follows the topography to the protection barrier nearby the tunnel. In the study, no calculations were made about the amount of water that flooded to the tunnel during theflooding in August 2013. Investigations of the climate change indicate that the amount of rainfall willincrease in the area. Therefore a further investigation is recommended, where the goal should be to protectthe tunnel from flooding. The method that has been used is applicable at any type of infrastructure. The Swedish TransportAdministration is recommended to use this method to investigate infrastructure and for future planning. / I augusti år 2013 översvämmades Norralatunneln strax norr om Söderhamn, vilket orsakade att ett tåg fastnade i tunneln. I framtiden förväntas intensiteten och mängden nederbörd att öka i detta område, vilket kan leda till en ökad risk för översvämning. Syftet med examensarbetet var att med GIS undersöka om det går att identifiera vilka järnvägstunnlar som är översvämningshotade vid kraftig nederbörd. GIS-analyser utfördes på Norralatunneln, där den Nationella Höjdmodellen användes som indata till undersökningen. Resultatet av studien innehåller ett antal kartor som redovisar avrinningsområden för samtliga tunnelmynningar och fuktighetsindex för den norra och mellersta räddningstunneln. Översvämningsanalysen visar att den räddningstunnel som översvämmades i augusti år 2013 har ett avrinningsområde på 1,1 km², vilket är mer än 20 gånger så stort som avrinningsområdet för någon av de andra tunnelmynningarna. Studien visar att GIS är ett bra verktyg för översvämningskartering och med den valda metoden i kombination med den Nationella Höjdmodellen är det möjligt att identifiera översvämningshotade tunnlar. Den fältstudien som genomfördes visar på brister i fastighetskartan gällande vattendrag. Mer än 90 % av vattnet som rann in i tunneln kom från västsidan av E4:an genom en älgpassage. Därefter leddes vattnet ner mot räddningstunneln via en grävd bäck som till en början följer fastighetskartans sträckning. Den tydligt grävda bäcken försvinner dock och vattnet följer därefter topografin till skyddsdiket intill tunnelmynningen.  I arbetet gjordes inga beräkningar på hur mycket vatten som flödade ner till tunneln i samband med översvämningen. Undersökningar av framtida klimat visar på att nederbördsmängden i området kommer att öka. Därför rekommenderas en vidare studie där målet borde vara att ta fram ett lämpligt alternativ för att skydda tunneln från översvämning. Analyserna som har utförts är tillämpningsbara även på andra typer av infrastruktur, därför rekommenderas Trafikverket att använda sig av metoden vid projektering och undersökning av infrastruktur.

This application is for the U.S. Department of Education’s Education Innovation and Research Program to secure funding for a market analysis to gauge the interest of Portland, Oregon parents for opening a two-way immersion (TWI) Romanian-American bilingual public charter school. Initial conversations with members of the Romanian community in the Portland area indicate that such interest may exist. A formal survey of that community has not yet been conducted to firmly establish the potential market for such a school. Moreover, there is evidence to document that such an educational option could increase the academic achievement of English Language Learners from Underrepresented Languages (ELL-UL). Some English Language Learners (ELL) face great academic challenges in today’s public educational system which may be masked within the larger ELL population. First generation Romanian children, as ELL students, are represented across the Portland metropolitan area. Although their presence is pervasive, they constitute only a small proportion of all students (2.4 percent of all students in one district). Because of the low incidence of Romanian students, and the fact they are enrolled in schools across a broad geographical area, practical barriers prohibit their participation in bilingual education programs compared to students from well-represented cultures and languages (e.g., Spanish). This project will conduct a market analysis to gauge the Portland Romanian community’s interest in opening a bilingual two-way immersion (TWI) public charter school, embracing both the Romanian culture and language. By documenting this interest, a clear direction and structure for such a school will be established, which should foster the academic success for children of Romanian heritage.

The objective of this diploma thesis is design and realization of I2C bus analyzer. I2C bus protocol is briefly described, together with means of connecting devices to the bus. Next the basic requirements for I2C bus analyzer are defined. Then the design of hardware I2C-to-USB converter including block description is proposed. The chapter dedicated to converter firmware describes method of communication with PC, decoding of intercepted commands and principles of master, slave and passive mode of bus monitoring. The last part is focused on operation software and its structure. Described are individual interfaces, most notable classes and default plugin modules.

Soil moisture is an important element in hydrological land-surface processes as well as land atmosphere interactions and has proven useful in numerous agronomical, climatological and meteorological studies. Since hydrological soil moisture estimates are usually point-based measurements at a specific site and time, spatial and temporal dynamics of soil moisture are difficult to capture. Soil moisture retrieval techniques in remote sensing present possibilities to overcome the abovementioned limitations by continuously providing distributed soil moisture data atdifferent scales and varying temporal resolutions. The main purpose of this study is to derive soil moisture estimates for the Stockholm region by means of two different approaches from a hydrological and a remote sensing point of view and the comparison of both methods. Soil moisture is both modelled with the Topographic Wetness Index (TWI) based on digital elevation data and with the Temperature‐Vegetation Dryness Index (TVDI) as a representation of land surface temperature and Normalized Difference Vegetation Index (NDVI) ratio. Correlations of both index distributions are investigated. Possible index dependencies onvegetation cover and underlying soil types are explored. Field measurements of soil moistureare related to the derived indices. The results indicate that according to a very low Pearson correlation coefficient of 0.023, nolinear dependency between the two indices existed. Index classification in low, medium and high value categories did not result in higher correlations. Neither index distribution is found to berelated to soil types and only the TVDI correlates alongside changes in vegetation cover distribution. In situ measured values correlate better with TVDIs, although neither index is considered to give superior results in the area due to low correlation coefficients. The decision which index to apply is dependent on available data, intent of usage and scale. The TWI surface is considered to be a more suitable soil moisture representation for analyses on smaller scaleswhereas the TVDI should prove more valuable on a larger, regional scale. The lack of correlation between the indices is attributed to the fact that they differ greatly in their underlying theories. However, the synthesis of hydrologic modelling and remote sensing is a promising field of research. The establishment of combined effective models for soil moisture determination over large areas requires more extensive in situ measurements and methods to fully assess the models’ capabilities, limitations and value for hydrological predictions.

På grund av ökad urbanisering och exploatering av grönområden i stadsnära miljöer fragmenteras och reduceras arters habitat vilket bland annat ligger till grund för den globalt minskade biologiska mångfalden. För att stärka och förbättra arters möjlighet till spridning i landskapet, och därmed säkra en hög biologisk mångfald, efterfrågas insamling av data och utveckling av nya metoder för att identifiera ekologiska kärnområden och för att analysera habitatnätverk. Syftet med den här studien är därför att 1) kartera och sammanställa biotoper i en biotopdatabas utifrån tolkning av infraröda flygbilder med digital stereofotogrammetri, 2) undersöka olika metoder att samla in data med hjälp av laser- och höjddata, och 3) att tillämpa landskapsekologisk analys på underlag i biotopkarteringen. Resultatet validerar att tolkning av infraröda flygbilder med digital stereofotogrammetri är en utmärkt källa för att kartera biotoper som medför en tolkningsnoggrannhet på 86 %. Valideringen av kateringen genomfördes med fältkontroller som utvärderades i felmatriser. En metod har även undersökts baserat på tidigare studier för att uppskatta busk- och krontäckning med hjälp av laserdata, men eftersom det saknas validering av resultatet bör den användas som en indikator för att visuellt uppskatta busk- och krontäckning i dagsläget. Fortsättningsvis har ett topografiskt fuktighetsindex (TWI) tillämpats med hjälp av höjddata för att uppskatta fuktighet i vegetationstäckta områden. Eftersom det saknas validering och tröskelvärden för att avgöra hur TWI ska klassificera olika fuktighetsgradienter, bör verktyget endast användas som en indikator för att visuellt uppskatta fuktighet tillsammans med tolkning av infraröda flygbilder. Om metoderna valideras med fältmätningar kan de bidra med att förbättra kvaliteten och tidseffektivisera kartering av biotoper. Biotopkarteringen fungerar som ett bra underlag vid tillämpning av landskapsekologisk analys. Med hjälp av MatrixGreen var det möjligt att modellera potentiella habitatnätverk för två olika arter inom studieområdet. På grund av en del problem med modelleringen i MatrixGreen bör resultaten beaktas med ett kritiskt angreppssätt, men kan eventuellt användas som ett underlag för framtida artinventeringar. / Due to urbanisation and exploitation of green areas in cities during the last decades, the rate of habitat fragmentation has increased, resulting in a decline in the global biodiversity. In order to strengthen the possibilities of species migration, and to secure a high biodiversity, there is an increasing demand in the collection of data and in the exploration of methods to identify ecological core areas and to analyse habitat networks at a landscape level. Therefore, this study aims to 1) map and organise biotopes in a biotope database using interpretation of colour infrared aerial photos in digital stereophotogrammetry, 2) to explore different methods using laser and elevation data in order to improve the collection of ecologically important attributes, and 3) to apply landscape ecological analysis on the collected biotope data. The results validate interpretation of colour infrared aerial photos with digital stereophotogrammetry as a key source in mapping biotopes with an overall accuracy of 86 %. A method to estimate bush and crown cover has been explored based on previous studies using laser data. It has however not been validated in this study and should therefore be used as an indicator and as support for visual estimation of bush and crown coverage using CIR aerial photo interpretation. Furthermore, a topographic wetness index (TWI) was applied using elevation data in order to estimate moisture regimes in vegetated areas. It should also be used as an indicator due to lack of verification and limitations of arranging TWI values in relation to different moisture regimes. However, if these two methods are validated using field collected data for example, they hold significant potential in improving mapping accuracies and mapping rates of different biotopes. Collected biotope data are well suited in the application of landscape ecological analysis. Using MatrixGreen, it was possible to analyse potential habitat networks of two different species within the study area. Due to some problems in the least cost path modeling in MatrixGreen, the results should be carefully assessed, but could probably be used as a background material for future species inventories.

Through-the-wall Imaging (TWI) is crucial for various applications such as law enforcement, rescue missions and defense. TWI methods aim to provide detailed information of spaces that cannot be seen directly. Current state-of-the-art TWI systems utilise ultra-wideband (UWB) signals to simultaneously achieve wall penetration and high resolution. These TWI systems transmit signals and mathematically back-project the reflected signals received to image the scenario of interest. However, these systems are diffraction-limited and encounter problems due to multipath signals in the presence of multiple scatterers. Time reversal (TR) methods have become popular for remote sensing because they can take advantage of multipath signals to achieve superresolution (resolution that beats the diffraction limit). The Decomposition Of the Time-Reversal Operator (DORT in its French acronym) and MUltiple SIgnal Classification (MUSIC) methods are both TR techniques which involve taking the Singular Value Decomposition (SVD) of the Multistatic Data Matrix (MDM) which contains the signals received from the target(s) to be located. The DORT and MUSIC imaging methods have generated a lot of interests due to their robustness and ability to locate multiple targets. However these TR-based methods encounter problems when the targets are behind an obstruction, particularly when the properties of the obstruction is unknown as is often the case in TWI applications. This dissertation introduces a novel total sub-MDM algorithm that uses the highly acclaimed MUSIC method to image targets hidden behind an obstruction and achieve superresolution. The algorithm utilises spatio-temporal windows to divide the full-MDM into sub-MDMs. The summation of all images obtained from each sub-MDM give a clearer image of a scenario than we can obtain using the full-MDM. Furthermore, we propose a total sub-differential MDM algorithm that uses the MUSIC method to obtain images of moving targets that are hiddenbehind an obstructing material.

Two-Way Immersion (TWI) programs offer settings and goals that foster multilingual and multicultural communities; however, communities are complex and fluid, and have aspects that may or may not promote equitable education and learning. This research analyzes the actions and interactions of a group of first grade students to address how community develops during the first semester of implementation of a TWI program. Theoretical notions of figured worlds and communities of practice frame the analysis of ethnographic data to provide insight into the complex social and pedagogical dynamics of this setting 1) through conversations with teachers, 2) through observations of teacher-student interactions during teacher-centered activities, and 3) through observations of students interacting with less teacher presence. Findings describe the teachers’ discourses about their students, which centered on issues of equity and dismantling language status hierarchies. The findings also describe practices that the teachers themselves frame as promoting unified, equitable communities; however, analysis was mixed in finding that certain practices appeared to promote unity within the classroom and others appeared to reinforce divisions among students. Key findings also confirm the results of other researchers regarding the positioning of initially bilingual students in TWI as “dual language experts.” This study notes some ramifications of teaching practices and aspects of the specific 50-50 TWI model for the entire community of learners, which, while elevating balanced bilinguals may marginalize English learners and Spanish learners. / text