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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
881

Sociala företags finansieringsproblematik : En litteraturstudie om bidragande faktorer till finansieringsgapet mellan sociala företag och dess finansiärer / The financial problem for social enterprises : A literature review on contributing factors to the funding gap between social enterprises and its financiers.

Lindgren, Håkan, Koznar, Jeanette, Nilsson, Sandra January 2017 (has links)
Titel: Sociala företags finansieringsproblematik: En litteraturstudie om bidragande faktorer till finansieringsgapet mellan sociala företag och dess finansiärer. Författare: Jeanette Koznar, Håkan Lindgren och Sandra Nilsson Handledare: Anders Wrenne Institution: Managementhögskolan, Blekinge Tekniska Högskola   Kurs: Kandidatarbete i Företagsekonomi, 15 högskolepoäng Syfte: Uppsatsens syfte är att identifiera det befintliga kunskapsläget för hur fem utvalda faktorerna påverkar finansiärers benägenhet att investera i sociala företag, för att därefter urskönja mönster mellan dessa fem faktorerna och diskutera hur ett samspelande kan minska finansieringsgapet. Metod:  Vi valde att använda oss av en explorativ litteraturstudie som metod då denna karaktäriseras av att fördjupa förståelsen för ett forskningsproblem.   Slutsatser: Vi fann att genom att se sambanden mellan de faktorer som påverkar finansieringsgapet, mellan sociala företag och finansiärer, kan flera faktorers inverkan på finansieringsgapet minskas framförallt genom att attackera en av dessa faktorer: de organisatoriska färdigheterna. / Title: The financial problem for social enterprises: A literature review on contributing factors to the funding gap between social enterprises and its financiers. Authors: Jeanette Koznar, Håkan Lindgren och Sandra Nilsson Supervisor: Anders Wrenne Department: School of Management, Blekinge Institute of Technology  Course: Bachelor’s thesis in Business Administration, 15 credits Purpose: The purpose of this essay is to identify the existing level of knowledge for how the five specifically chosen factors affect financiers' propensity to invest in social enterprises, and descry patterns between these five factors and discuss how an interaction between them can reduce the funding gap.   Method: We chose an exploratory literature review as a method to conduct this study based on that it is characterized by further deepening the understandings of a specific research problem.   Results: We found that by investigating the connection between the factors that contribute to the funding gap between social enterprises and financiers, the impact on the funding gap can be reduced primarily by attacking one of these factors: the organizational skills.
882

An ultra-low duty cycle sleep scheduling protocol stack for wireless sensor networks

Kleu, Christo 18 July 2012 (has links)
A wireless sensor network is a distributed network system consisting of miniature spatially distributed autonomous devices designed for using sensors to sense the environment and cooperatively perform a specific goal. Each sensor node contains a limited power source, a sensor and a radio through which it can communicate with other sensor nodes within its communication radius. Since these sensor nodes may be deployed in inaccessible terrains, it might not be possible to replace their power sources. The radio transceiver is the hardware component that uses the most power in a sensor node and the optimisation of this element is necessary to reduce the overall energy consumption. In the data link layer there are several major sources of energy waste which should be minimised to achieve greater energy efficiency: idle listening, overhearing, over-emitting, network signalling overhead, and collisions. Sleep scheduling utilises the low-power sleep state of a transceiver and aims to reduce energy wastage caused by idle listening. Idle listening occurs when the radio is on, even though there is no data to transmit or receive. Collisions are reduced by using medium reservation and carrier sensing; collisions occur when there are simultaneous transmissions from several nodes that are within the interference range of the receiver node. The medium reservation packets include a network allocation vector field which is used for virtual carrier sensing which reduces overhearing. Overhearing occurs when a node receives and decodes packets that are not destined to it. Proper scheduling can avoid energy wastage due to over-emitting; over-emitting occurs when a transmitter node transmits a packet while the receiver node is not ready to receive packets. A protocol stack is proposed that achieves an ultra-low duty cycle sleep schedule. The protocol stack is aimed at large nodal populations, densely deployed, with periodic sampling applications. It uses the IEEE 802.15.4 Physical Layer (PHY) standard in the 2.4 GHz frequency band. A novel hybrid data-link/network cross-layer solution is proposed using the following features: a global sleep schedule, geographical data gathering tree, Time Division Multiple Access (TDMA) slotted architecture, Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), Clear Channel Assessment (CCA) with a randomised contention window, adaptive listening using a conservative timeout activation mechanism, virtual carrier sensing, clock drift compensation, and error control. AFRIKAANS : 'n Draadlose sensor-netwerk is 'n verspreide netwerk stelsel wat bestaan uit miniatuur ruimtelik verspreide outonome toestelle wat ontwerp is om in harmonie saam die omgewing te meet. Elke sensor nodus besit 'n beperkte bron van energie, 'n sensor en 'n radio waardeur dit met ander sensor nodusse binne hulle kommunikasie radius kan kommunikeer. Aangesien hierdie sensor nodusse in ontoeganklike terreine kan ontplooi word, is dit nie moontlik om hulle kragbronne te vervang nie. Die radio is die hardeware komponent wat van die meeste krag gebruik in 'n sensor nodus en die optimalisering van hierdie element is noodsaaklik vir die verminder die totale energieverbruik. In die data-koppelvlak laag is daar verskeie bronne van energie vermorsing wat minimaliseer moet word: ydele luister, a uistering, oor-uitstraling, oorhoofse netwerk seine, en botsings. Slaap-skedulering maak gebruik van die lae-krag slaap toestand van 'n radio met die doel om energie vermorsing wat veroorsaak word deur ydele luister, te verminder. Ydele luister vind plaas wanneer die radio aan is selfs al is daar geen data om te stuur of ontvang nie. Botsings word verminder deur medium bespreking en draer deteksie; botsings vind plaas wanneer verskeie nodusse gelyktydig data stuur. Die medium bespreking pakkies sluit 'n netwerk aanwysing vektor veld in wat gebruik word vir virtuele draer deteksie om a uistering te verminder. Afluistering vind plaas wanneer 'n nodus 'n pakkie ontvang en dekodeer maar dit was vir 'n ander nodus bedoel. Behoorlike skedulering kan energie verkwisting as gevolg van oor-uistraling verminder; oor-uistraling gebeur wanneer 'n sender nodus 'n pakkie stuur terwyl die ontvang nog nie gereed is nie. 'n Protokol stapel is voorgestel wat 'n ultra-lae slaap-skedule dienssiklus het. Die protokol is gemik op draadlose sensor-netwerke wat dig ontplooi, groot hoeveelhede nodusse bevat, en met periodiese toetsing toepassings. Dit maak gebruik van die IEEE 802.15.4 Fisiese-Laag standaard in die 2.4 GHz frekwensie band. 'n Nuwe baster datakoppelvlak/netwerk laag oplossing is voorgestel met die volgende kenmerke: globale slaap-skedulering, geogra ese data rapportering, Tyd-Verdeling-Veelvuldige-Toegang (TVVT) gegleufde argitektuur, Draer-Deteksie-Veelvuldige-Toegang met Botsing-Vermyding (DDVT/BV), Skoon-Kanaal-Assessering (SKA) met 'n wisselvallige twis-tydperk, aanpasbare slaap-skedulering met 'n konserwatiewe aktiverings meganisme, virtuele draer-deteksie, klok-wegdrywing kompensasie, en fout beheer. Copyright / Dissertation (MEng)--University of Pretoria, 2012. / Electrical, Electronic and Computer Engineering / unrestricted
883

Classificação de dados estacionários e não estacionários baseada em grafos / Graph-based classification for stationary and non-stationary data

João Roberto Bertini Júnior 24 January 2011 (has links)
Métodos baseados em grafos consistem em uma poderosa forma de representação e abstração de dados que proporcionam, dentre outras vantagens, representar relações topológicas, visualizar estruturas, representar grupos de dados com formatos distintos, bem como, fornecer medidas alternativas para caracterizar os dados. Esse tipo de abordagem tem sido cada vez mais considerada para solucionar problemas de aprendizado de máquina, principalmente no aprendizado não supervisionado, como agrupamento de dados, e mais recentemente, no aprendizado semissupervisionado. No aprendizado supervisionado, por outro lado, o uso de algoritmos baseados em grafos ainda tem sido pouco explorado na literatura. Este trabalho apresenta um algoritmo não paramétrico baseado em grafos para problemas de classificação com distribuição estacionária, bem como sua extensão para problemas que apresentam distribuição não estacionária. O algoritmo desenvolvido baseia-se em dois conceitos, a saber, 1) em uma estrutura chamada grafo K-associado ótimo, que representa o conjunto de treinamento como um grafo esparso e dividido em componentes; e 2) na medida de pureza de cada componente, que utiliza a estrutura do grafo para determinar o nível de mistura local dos dados em relação às suas classes. O trabalho também considera problemas de classificação que apresentam alteração na distribuição de novos dados. Este problema caracteriza a mudança de conceito e degrada o desempenho do classificador. De modo que, para manter bom desempenho, é necessário que o classificador continue aprendendo durante a fase de aplicação, por exemplo, por meio de aprendizado incremental. Resultados experimentais sugerem que ambas as abordagens apresentam vantagens na classificação de dados em relação aos algoritmos testados / Graph-based methods consist in a powerful form for data representation and abstraction which provides, among others advantages, representing topological relations, visualizing structures, representing groups of data with distinct formats, as well as, supplying alternative measures to characterize data. Such approach has been each time more considered to solve machine learning related problems, mainly concerning unsupervised learning, like clustering, and recently, semi-supervised learning. However, graph-based solutions for supervised learning tasks still remain underexplored in literature. This work presents a non-parametric graph-based algorithm suitable for classification problems with stationary distribution, as well as its extension to cope with problems of non-stationary distributed data. The developed algorithm relies on the following concepts, 1) a graph structure called optimal K-associated graph, which represents the training set as a sparse graph separated into components; and 2) the purity measure for each component, which uses the graph structure to determine local data mixture level in relation to their classes. This work also considers classification problems that exhibit modification on distribution of data flow. This problem qualifies concept drift and worsens any static classifier performance. Hence, in order to maintain accuracy performance, it is necessary for the classifier to keep learning during application phase, for example, by implementing incremental learning. Experimental results, concerning both algorithms, suggest that they had presented advantages over the tested algorithms on data classification tasks
884

Odhad dechové frekvence z elektrokardiogramu a fotopletysmogramu / Breathing Rate Estimation from the Electrocardiogram and Photoplethysmogram

Janáková, Jaroslava January 2021 (has links)
The master thesis deals with the issue of gaining the respiratory rate from ECG and PPG signals, which are not only in clinical practice widely used measurable signals. The theoretical part of the work outlines the issue of obtaining a breath curve from these signals. The practical part of the work is focused on the implementation of five selected methods and their final evaluation and comparison.
885

In-Plane Lateral Load Capacities of Vertically Oriented Interlocking Timber Panels

Decker, Brandon T 01 July 2014 (has links)
The Vertically Oriented Interlocking Timber (VOIT) panel is a new solid wood panel similar to Interlocking Cross Laminated Timber (ICLT) and the more commonly known Cross Laminated Timber (CLT). Like ICLT, VOIT panels use timber connections instead of the adhesives or metal fasteners common to CLT. The difference of VOIT is the orientation of the layers. Where CLT and ICLT panels alternate the orientation of each layer, VOIT panels orient all the layers in the same direction. The vertically oriented layers are then attached to one another by smaller horizontal dovetail members.Two types of VOIT panels were provided to be tested for in-plane lateral loading. Type I had three rows of horizontal dovetail members connecting the layers and Type II had four rows of dovetail members as well as two diagonal members to provide stiffness. Two panels of each type were provided, measuring 8 ft. wide, 8 ft. tall, and 13.75 in. thick. Each panel was disassembled after monotonic lateral in-plane loading to determine possible failure modes. Testing results suggest the VOIT panels to be comparable in shear strength to other wood shear walls, including light frame, CLT, and ICLT walls. A two-part analytical model was created to determine the deflection of the wall when loaded as well as the shear strength of the wall. The model predicted deflection and wall strength reasonably well. Due to the small sample size, additional testing is necessary to confirm the results of the Type I and Type II VOIT panels. Additional testing with more variations of the panel and member geometries is also needed to validate the scope of the model.
886

A Temperature stabilised CMOS VCO based on amplitude control

Sebastian, Johny January 2013 (has links)
Speed, power and reliability of analogue integrated circuits (IC) exhibit temperature dependency through the modulation of one or several of the following variables: band gap energy of the semiconductor, mobility, carrier diffusion, current density, threshold voltage, interconnect resistance, and variability in passive components. Some of the adverse effects of temperature variations are observed in current and voltage reference circuits, and frequency drift in oscillators. Thermal instability of a voltage-controlled oscillator (VCO) is a critical design factor for radio frequency ICs, such as transceiver circuits in communication networks, data link protocols, medical wireless sensor networks and microelectromechanical resonators. For example, frequency drift in a transceiver system results in severe inter-symbol interference in a digital communications system. Minimum transconductance required to sustain oscillation is specified by Barkhausen’s stability criterion. However it is common practice to design oscillators with much more transconductance enabling self-startup. As temperature is increased, several of the variables mentioned induce additional transconductance to the oscillator. This in turn translates to a negative frequency drift. Conventional approaches in temperature compensation involve temperature-insensitive biasing proportional-to-absolute temperature, modifying the control voltage terminal of the VCO using an appropriately generated voltage. Improved frequency stability is reported when compensation voltage closely follows the frequency drift profile of the VCO. However, several published articles link the close association between oscillation amplitude and oscillation frequency. To the knowledge of this author, few published journal articles have focused on amplitude control techniques to reduce frequency drift. This dissertation focuses on reducing the frequency drift resulting from temperature variations based on amplitude control. A corresponding hypothesis is formulated, where the research outcome proposes improved frequency stability in response to temperature variations. In order to validate this principle, a temperature compensated VCO is designed in schematic and in layout, verified using a simulation program with integrated circuit emphasis tool using the corresponding process design kit provided by the foundry, and prototyped using standard complementary metal oxide semiconductor technology. Periodic steady state (PSS) analysis is performed using the open loop VCO with temperature as the parametric variable in five equal intervals from 0 – 125 °C. A consistent negative frequency shift is observed in every temperature interval (≈ 11 MHz), with an overall frequency drift of 57 MHz. However similar PSS analysis performed using a VCO in the temperature stabilised loop demonstrates a reduced negative frequency drift of 3.8 MHz in the first temperature interval. During the remaining temperature intervals the closed loop action of the amplitude control loop overcompensates for the negative frequency drift, resulting in an overall frequency spread of 4.8 MHz. The negative frequency drift in the first temperature interval of 0 to 25 °C is due to the fact that amplitude control is not fully effective, as the oscillation amplitude is still building up. Using the temperature stabilised loop, the overall frequency stability has improved to 16 parts per million (ppm)/°C from an uncompensated value of 189 ppm/°C. The results obtained are critically evaluated and conclusions are drawn. Temperature stabilised VCOs are applicable in applications or technologies such as high speed-universal serial bus, serial advanced technology attachment where frequency stability requirements are less stringent. The implications of this study for the existing body of knowledge are that better temperature compensation can be obtained if any of the conventional compensation schemes is preceded by amplitude control. / Dissertation (MEng)--University of Pretoria, 2013. / Electrical, Electronic and Computer Engineering / unrestricted
887

Diffusion on Fractals

Prehl, geb. Balg, Janett 21 March 2006 (has links)
We study anomalous diffusion on fractals with a static external field applied. We utilise the master equation to calculate particle distributions and from that important quantities as for example the mean square displacement <r^2(t)>. Applying different bias amplitudes on several regular Sierpinski carpets we obtain maximal drift velocities for weak field strengths. According to <r^2(t)>~t^(2/d_w), we determine random walk dimensions of d_w<2 for applied external fields. These d_w corresponds to superdiffusion, although diffusion is hindered by the structure of the carpet, containing dangling ends. This seems to result from two competing effects arising within an external field. Though the particles prefer to move along the biased direction, some particles get trapped by dangling ends. To escape from there they have to move against the field direction. Due to the by the bias accelerated particles and the trapped ones the probability distribution gets wider and thus d_w<2. / In dieser Arbeit untersuchen wir anomale Diffusion auf Fraktalen unter Einwirkung eines statisches äußeres Feldes. Wir benutzen die Mastergleichung, um die Wahrscheinlichkeitsverteilung der Teilchen zu berechnen, um daraus wichtige Größen wie das mittlere Abstandsquadrat <r^2(t)> zu bestimmen. Wir wenden unterschiedliche Feldstärken bei verschiedenen regelmäßigen Sierpinski-Teppichen an und erhalten maximale Driftgeschwindigkeiten für schwache Feldstärken. Über <r^2(t)>~t^{2/d_w} bestimmen wir die Random-Walk-Dimension d_w als d_w<2. Dieser Wert für d_w entspricht der Superdiffusion, obwohl der Diffusionsprozess durch Strukturen des Teppichs, wie Sackgassen, behindert wird. Es schient, dass dies das Ergebnis zweier konkurrierender Effekte ist, die durch das Anlegen eines äußeren Feldes entstehen. Einerseits bewegen sich die Teilchen bevorzugt entlang der Feldrichtung. Andererseits gelangen einige Teilchen in Sackgassen. Um die Sackgassen, die in Feldrichtung liegen, zu verlassen, müssen sich die Teilchen entgegen der Feldrichtung bewegen. Somit sind die Teilchen eine gewisse Zeit in der Sackgasse gefangen. Infolge der durch das äußere Feld beschleunigten und der gefangenen Teilchen, verbreitert sich die Wahrscheinlichkeitsverteilung der Teilchen und somit ist d_w<2.
888

Classification of a Sensor Signal Attained By Exposure to a Complex Gas Mixture

Sher, Rabnawaz Jan January 2021 (has links)
This thesis is carried out in collaboration with a private company, DANSiC AB This study is an extension of a research work started by DANSiC AB in 2019 to classify a source. This study is about classifying a source into two classes with the sensitivity of one source higher than the other as one source has greater importance. The data provided for this thesis is based on sensor measurements on different temperature cycles. The data is high-dimensional and is expected to have a drift in measurements. Principal component analysis (PCA) is used for dimensionality reduction. “Differential”, “Relative” and “Fractional” drift compensation techniques are used for compensating the drift in data. A comparative study was performed using three different classification algorithms, which are “Linear Discriminant Analysis (LDA)”, “Naive Bayes classifier (NB)” and “Random forest (RF)”. The highest accuracy achieved is 59%,Random forest is observed to perform better than the other classifiers. / <p>This work is done with DANSiC AB in collaboration with Linkoping University.</p>
889

Statsförvaltningen och dess problem : En fallstudie om orsaker till transportstyrelseskandalen och genomgång av processen som ledde till avsteget från lagen

Öberg, Jonathan January 2020 (has links)
No description available.
890

Jämförelse mellan bullerreducerande beläggning och bullerskärm. : Ur ett kostnads- och tekniskt perspektiv. / Comparison between noise reducing pavement and noise barriers. : From a cost and technical perspective.

Cardenas, Pablo, Wall, Peter January 2013 (has links)
Den bullerreducerande beläggnigen har en porös struktur som förbättrar dräneringen och reducerar buller vid källan men egenskaperna orsakar ett snabbt slitage och portäppning. Detta medför att beläggningen måste omläggas och rengöras oftare än en konventionell beläggning som t.ex. ABS 16. Kritiken mot den bullerreducerande beläggningen riktar sig på de höga drift- och underhållskostnaderna, detta gör att många väghållaren satsar på bullerskärm som bulleråtgärd.  Syftet med arbetet är att jämföra bullerreducerande beläggning med bullerskärm, för att reda på vilken bulleråtgärd är mer kostnadseffektivt under 20 år. Ett teoriavsnitt kommer att förklara och beskriva på ett tekniskt sätt: väg, ljud och buller, bullerskärm och bullerreducerande beläggningar. Kostnadsjämförelsen mellan bulleråtgärderna omfattar investering, drift och underhåll. Den fördjupar sig på en befintlig sträcka vid Gamla Enskede i Nynäsvägen, där det sedan 2012 finns bullerskärmar. De riktiga priserna av skärmarna ställs mot priserna för en eventuell bullerreducerande beläggning i sträckan. Priserna, antal omläggningar och bullerreducerande förlusten per år för den bullerreducerande beläggningen blev antagna genom beräkningar utifrån verkliga sträckor. Med hjälp av kalkyler och diagram kunde det noteras att bullerskärmarna är dyrare än bullerreducerande beläggningen. Förklaring av kostnadsresultat medföljs av rekommendationer som anses vara relevanta för att ha i åtanke för framtida val av bullerreducerande åtgärder. / Noise reducing pavement has a porous structure that improves drainage and reduces traffic noise but these propitious qualities causes’ problems such as rapid wear and pore clogging. This means that the pavement must be repaved and cleaned more frequently than a conventional pavement such as ABS 16. Criticism of the noise reducing pavement has been raised and has to do with the high operating and maintenance costs, this result in more invests in noise barriers instead. The purpose with this review is to compare noise reducing pavement with noise barriers, in order to determine which noise provision is more cost effective during a period of 20 years.  There will be a theory chapter were it will be explain and describe in a technical method: Road, sound and noise, noise barriers and noise-reducing pavement. Cost comparison of noise provisions includes investment-, operation- and maintenance cost. This review immerses on an existing road at Gamla Enskede in Nynäsvägen, which since 2012 has noise barriers. The actual prices of the noise barriers in Gamla Enskede will be compared to a possible noise reducing pavement. Prices, quantity of pavement replacement and noise loss per year for the noise reducing pavement was presumed by calculations based on actual distances with noise reducing pavement. Observation of our calculations and charts reveals that noise barriers are more expensive than noise reducing pavement.  Explanations of cost results are accompanied by recommendations that are considered relevant to have in mind for future choices of noise reduction provisions.

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