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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.
381

High Level Synthesis Evaluation of Tools and Methodology

Namvar Gharehshiran, Amir January 2014 (has links)
The advances in silicon technology, as well as competitive time to market, in the recent decade have forced the design tools and methodologies to progress towards higher levels of abstraction. Raising the level of abstraction shortens the design cycle via elimination of details in design specification. One such new methodology is High Level Synthesis (HLS). HLS tools accept the behavioral design in the abstract level as the input and generate the detailed Register Transfer Level (RTL) code. In this thesis project, the HLS methodology is introduced in the design flow and its advantages are outlined. We then evaluate and compare three HLS tools developed by market leading vendors, namely, C-to-Silicon, CatapultC and Synphonycc. To compare the HLS tools, an HLS input is developed for one of the Ericsson’s designs and the generated RTL is compared with the hand-written RTL based on several performance criteria. Thereof, we discuss the choice of the best tool so as to facilitate adoption of HLS in Ericsson’s design flow. At last, capability of the HLS tools in the synthesis of designs with pure control flow is investigated.
382

Efficient Distributed Pipelines for Anomaly Detection on Massive Production Logs

Chen, Xiao January 2014 (has links)
The data volume of live corporate production logs is increasingly growing every day. On one hand, companies have to handle millions of data produced daily by their services which require high storage capacity. On the other hand, relevant information can be extracted from this massive amount of data and used for analysis according to different requirements, such as generating behavior patterns, detecting anomalies and making predictions. All of these can be achieved by machine learning and data mining techniques where the distributed platforms provide the computation ability and memory storage capacity for data intensive processing. Services such as payment monitoring in a company are very sensitive and require fast anomaly detection over streams of transactions. However, traditional anomaly detection techniques using distributed batch processing platforms such as Hadoop is very expensive to run and the anomalies cannot be detected in real time. In order to overcome this drawback, Distributed Stream Processing (DSP) platforms such as Storm have proven to be a more flexible and powerful tool for dealing with such streams. Furthermore, since the anomaly patterns in data streams are not predefined and may change over time, unsupervised learning algorithms such as clustering should be used first to output significant anomalies which contribute to forming and updating anomaly patterns. The real-time anomaly detection on new data streams can be established by such patterns. This thesis project is aiming at providing a distributed system on top of Storm combining both batch-based unsupervised learning and streaming rule-based methods to detect anomalies in Spotify payment transactions in real time. The anomaly detection system implements k-means and DBSCAN clustering algorithms as an unsupervised learning module to find out anomalous behaviors from payment transaction streams. Based on those anomalies, the frequent item set algorithm estDec is implemented to extract anomaly patterns. Stratified Complex Event Processing (CEP) engines based on Esper get reconfigured with such patterns to do rule-based anomaly detection in real time over absolute time sliding windows. Experimental results indicate that such a complex system over a unified data flow pipeline is feasible to detect anomalies in real time by rule-based anomaly detection with CEP engine. Unsupervised learning methods can provide light weighted batch (nearly real time) based anomaly detection but different factors heavily influence the performance. The rule-based method shows that it performs better in the heavy anomaly density scenario in terms of sensitivity and lower detection latency.
383

Identity Federation Using Multidomain Authentication in PKI

Rasheed, Mohsin January 2014 (has links)
Today’s enterprises are facing some basic business challenges for which identity federation solutions are uniquely suited. Most online applications and ecommerce incorporate partner integration that provides to the user secure access to the partner’s site without needing to sign-on again. Additionally, organizations must provide these SSO services without having to add large numbers of users to an enterprise directory or having to manage those identities over time. A trust mechanism must exist in order to allow users who are authenticated in one domain to be trusted in a another domain. Finally, these technical challenges must be managed within the constraints of existing business and legal agreements that define thresholds for acceptable use, risk and indemnification. [14] The purpose of this thesis is to model a framework and to suggest the requirements needed of the Public Key Infrastructure for the multiple domain interoperability. This model describes the relationship between certificate authorities for establishing the trust mechanism through the techniques which are described in details of the design model description.
384

Micro-Power Inverter-Based Continuous-Time Sigma-Delta Modulator for Biosensor Applications

Chi, Jiazuo January 2014 (has links)
Biosensor applications have made promising progress during the last decade, presenting potentials and challenges at the same time. Meanwhile, digital signal processing (DSP) has become even more powerful than before, due to Moore's Law. Bridging the biosensor applications and the digital circuits, analog-to-digital converters (ADCs) are a critical block that inuences the performance of the entire system, in terms of speed, accuracy and power. Particularly, incremental ΣΔ (IΣΔ) ADCs have recently received increasing research interest because of their high-resolution feature and the ability to time-multiplex different channels of input signals, making them especially suitable for neuro-science studies and brain-computer-interface (BCI). However, IΣΔ ADCs are less power-ecient than traditional ΣΔ ADCs. To improve the power eciency and reduce the chip size, an inverter-based continuous-time (CT) Sigma-Delta (ΣΔ) modulator is proposed, to be integrated in a two-step I(ΣΔ) ADC previously designed. Inverter-based operational transconductance amplifers (OTA) have recently demonstrated their high power efficiency in multiple ΣΔ modulators, most of which are discrete-time (DT) implementation. CT implementation is investigated in this thesis for the possibility to further reduce power consumption, due to its more relaxed requirements on bandwidth and settling compared to the DT counterpart. In the circuit implementation of the modulator, fully-differential topology is used in inverter-based CT ΣΔ ADCs for the rst time. Compared to pseudo-differential topology, fully-differential topology has more precise control on the operating point and the quiescent power. The post-layout simulation result shows that the modulator achieves a peak SNDR of 58.1 dB, and a dynamic range of 65.9 dB. The entire modulator consumes 1.28 μW from a 1.2 V supply voltage, on a chip area of only 0.07 mm2. This corresponds to a FoM of 243 fJ/(conv. step).
385

Wireless sensor networks in building automation systems

Pramsten, Erik, Roberthson, Daniel January 2014 (has links)
Tiny devices communicating wirelessly, also called wireless sensor networks, have developed rapidly the last few years. As the devices have been more energy efficient and more reliable new application areas have become interesting, one of them is building automation systems. Retrotting and additional temperature measurements are two interesting application areas to make the building automation systems more cost and energy efficient. The aim for the work preformed has been to investigate the possibility of integrating wireless networks with existing building automation systems using open and widely used standards. The work process has involved evaluating existing business automation protocols. Each protocol has then been evaluated from an energy consumption perspective. The major dierent wireless technologies have been described in relation to the sensor networks. Finally a proof of concept implementation has been developed on a wireless sensor network connecting to a building automation system. The implementation has been made on the Contiki operating system, a lightweight operating system for small devices. The work described in this master thesis shows that the Contiki operation systems with BACnet can be used to enhance existing building automation systems with wireless sensor network support. All listed protocols however lacks functionality for reducing number of messages required for protocol comparability (and reducing power consumption). / Små enheter som kommunicerar trådlöst ofta benämnda som sensornätverk har under senare år utvecklats i hög takt. Nya applikationsområden har blivit intressanta allt eftersom enheterna har blivit mer energieektiva och tillförlitliga. Ett av dessa nya applikationsområden är fastighetsautomation, speciellt vi ombyggnation och utökad temperaturkontroll. Dessa områden är intressanta eftersom trådlösa sensornätverk kan innebära utökad kontroll och har en låg installationskostnad. Målet med arbetet har varit att undersöka hur väl trådlösa sensornätverk kan integreras med existerande system för fastigautomation. Metoden för detta har inkluderat en genomgång av system för fastighetsautomation samt kända protokoll för detta. Varje protokoll har evaluerats utifrån protokollets kommunikationsmetod och uppskattad energiåtgång. Arbetet innehåller en genomgång av olika trådlösa nätverksprotokoll och hur de relaterar till sensornätverk. Slutligen har vi utvecklat en testapplikation på enheter anpassade för sensornätverk och integrerat denna med BACnet ett protokoll för fastighetsautomation. Arbetet som beskrivs i denna uppsats visar att det går att integrera system för fastighetsautomation med trådlösa sensornätverk. Däremot saknar alla beskrivna protokoll för fastighetsautomation stöd för att minska strömförbrukning och kommunikation, vilket är en viktig del för implementeringen av större trådlösa nätverk.
386

Grund för effektiv administration av examensarbeten

Schillén, Anton January 2014 (has links)
Som det ser ut idag är hanteringen av examensarbeten, både kandidat och master långt från optimal på Kungliga Tekniska Högskolan (KTH). Administration av detta är onödigt tidskrävande, eftersom det finns ingen överblickbarhet och det är svårt att koppla ihop student med en passande examinator. Bara processen att anmäla studenterna till kursen är en process i flera steg som måste gå igenom många personer. Lösningen som ska ges är ett system som underlättar några steg tillhörande examensarbeten. För att hitta vad för funktioner ett sådant system måste kunna erbjuda utförs studie med hjälp av intervjuer med de som idag administrerar examensarbeten. Resultatet från intervjuerna sammanställdes till en kravspecifikation som sedan användes som bas för att bygga ett system. Systemet består av två grundkomponenter, en databas och en webbapplikation. Webbapplikationen tillåter användaren att komma åt listor sparade i databasen. För att utvärdera systemet sker återkoppling till dessa nyckelpersoner för att erhålla feedback. Uppsatsens resultat består av presentationen utav kravspecifikation, databasdesign och en prototyp av webbapplikationen som är framtagen under arbetet. Huvudmålet är att skapa en prototyp som kan användas av studenter, handledare och examinatorer. De områden som problemet berör är administration, distribuerade system och sammankoppling av resurser.
387

Facebook en ny datakälla : En studie om extraktion av positiv eller negativ lojalitet hos en individ från extern data

Ljungström, Caroline January 2014 (has links)
Idag kretsar samhället runt sociala medier. Allt fler sociala plattformar skapas där människor kan dela med sig av händelser, åsikter och intressen. Sociala medier kan ses som en stor informationskälla med data över individers åsikter och upplevelser. Denna rapport presenterar en studie som undersöker om det finns starka attribut på individnivå som kan extraheras från sociala plattformer för att ge ökad företagsnytta. Genom att undersöka en social plattform och hitta samband mellan vissa attribut hos en individ kan omdöme skapas om hur dessa förhåller sig till ett företags vinstdrivande egenskaper, vilket kan gynna företag. Studien kommer även att undersöka vilka möjligheter det finns att extrahera denna information ur en social plattform. Syftet med rapporten är att påvisa nya möjligheter att ta ut extern data för analys och vilka attribut som kan vara väsentliga. Resultatet från insamling av data från extern datakälla påvisade flera attribut som indikerar individens positiva eller negativa lojalitet. / Social media is a central part of today’s society. Increasingly more social platforms are created where people are able to share events, opinions and interests. Social media can be viewed as an extended information source containing data of individual’s opinions and experiences. This report studies whether there are strong attributes on individual’s level that can be extracted from the social platform, which may give increased corporate benefit. By examining a social platform and finding correlations between certain attributes of an individual and judge how they relate to a company's profit making features, which statistically may benefit the company. The study will also examine how to extract this information from a social platform. The report aims to show new opportunities to extract the external data for analysis and which attributes are essential. The result from the collection of data from external data source revealed several attributes which indicates an individual's positive or negative loyalty towards the company
388

Visualisering av vinddata i iOS

Rådell, Dennis, af Sandeberg, Joakim January 2014 (has links)
Att visualisera vind på ett lättförståeligt sätt är en svår uppgift, därför undersöker denna uppsats hur visualisering av vinddata kan ske på en iOS enhet genom att använda strömlinjealgoritmer, samt hur användaren kan tilldelas senast möjliga väderdata under flygning. Målet med arbetet är att visualisera vind med hjälp av strömlinjer för privatpiloter före och under flygning. Uppsatsen presenterar en prototyp av ett delsystem gjort för iPad i programmeringsspråket Objective C, med tillhörande funktioner som hämtning och bearbetning av väderdata och funktioner för uppritning på en karta. Bilder på resultatet och exempel ur koden ges för att bättre förklara hur delsystemet är uppbyggd. / Visualizing wind in a way that is easy to understand is a difficult task, and this paper investigates how the visualization of wind data can be done on an iOS device using the streamlining algorithm, and how the user can be presented the latest possible weather data during flight. The goal of this project is to visualize the wind using streamlines to be used by private pilots before and during flight. The thesis presents a prototype of a subsystem designed for an iPad in the programming language Objective C, with associated functions such as retrieving and manipulating weather data and functions for plotting on a map. Pictures of the results and examples of code given to better explain how the subsystem is constructed.
389

Development of a Rotary CNC System

Bosco, Bruno, Larsson, Jimmy January 2014 (has links)
The Rotary CNC system is a novel way to position a tool in the XY-plane. The system is meant to be used in areas such as 3D-printing, laser cutting, CNC milling and other rapid prototyping equipment. Benets include lower production cost, less moving parts and a small physical footprint. This thesis has provided a "Proof of Concept" prototype of the Rotary CNC system. It has been shown that the system is a viable alternative to current CNC system designs in the eld of PCB routing.
390

Analysis of the use of self-organization and subtle control in software projects

Mosquera Moya, Marlene Pilar January 2014 (has links)
På senare tid har användandet av Scrum som verktyg för att organisera och hantera programutvecklingsprojekt växt avsevärt. Scrum anses av många som den bästa metodiken för programvaruutveckling, p.g.a. dess flexibilitet och tekniker för att hantera snabbt förändrade krav och lagarbete. De flesta av framgångarna för Scrum vilar på priniciperna för självorganisering och “subtil kontroll”. Med Scrum arbetar utvecklingsteamet självständig, utan direkt kontroll, och övervakning och påverkan utifrån är minimal. Trots fördelar och de möjligheter till att lyckas som Scrum erbjuder så har dess införande inte alltid varit en helt positiv upplevelse för användarna. Självorganisering och subtil kontroll må vara utomordentliga principer för att främja samarbete och självförbättring, men de kan även orsaka riskabla situationer när de missförstås eller inte appliceras alls. Avsaknad av auktoritet och ledarskap är typiska risker med alltför självorganiserande team, medan obehag och frustration kan bli följden av för mycket kontroll och påverkan utifrån på teamet och dess aktiveter. I båda fallen blir resultatet ett hinder som äventyrar den stabilitet och ordning som måste finnas på arbetsplatsen. Studien har för avsikt att åskådliggöra orsakerna till sådana extrema situationer. Genom analys av information inhämtad från scrumanvändare, visar undersökningen på möjliga orsaker till varför självorganisation och subtil kontroll ibland inte fungerar som väntat, samt de negativa konsekvenser som detta kan få på ett projekt. Slutsatserna återspeglar även hur människor uppfattar och applicerar självorganisation och subtil kontroll, samt hur de tolkar och antar sina roller under processens gång. Andra relevanta frågor som har noterats i undersökningen är hur scrummästaren och teammedlemmarna hanterar problems såsom avsaknad av auktoritet eller överdriven påverkan utifrån. Utfallet från studien visar att en gedigen introduktion och utbildning i scrumteori och dess principer är viktigt för att undvika risker. Resultaten har också påvisat betydelsen av en aktiv, genomgående kommunikation och engagemang bland alla roller som är delaktiga i projektet, för att slippa onödiga konflikter och påfrestningar. Sammanfattningen och slutsatserna inkluderar även en kort beskrivning av vad som kan förbättras för att undvika att extrem självorganisation eller överdriven kontroll inträffar, eller åtminstone minimera deras negativa inverkan på projektet. / In recent years, the use of the Scrum methodology as a tool to organize and manage software development projects, has grown considerably among organizations. Due to its flexibility and approach to handle fast changing requirements and enabling team work and improvement, Scrum is considered by many software professionals to be the best alternative to implement their solutions. Most of the success of Scrum rests upon the concepts of self-organization and subtle control. With Scrum, teams work independently whereas control is applied indirectly and supervision and intervention are minimal. However, in spite of all the benefits and possibilities for success that Scrum offers, for many of its users not everything has been quite a happy experience. Indeed, self-organization and subtle control may be excellent principles to encourage cooperation and self-improvement, but they can also trigger dangerous situations when not applied or understood properly. Loss of authority and direction are typical risks with excessively self-organized teams, whereas discomfort and frustration are the results of too much control and intervention over the teams and their activities. Eventually, either case becomes an obstacle that jeopardizes the stability and order that shall exist within the working environment. The study helps visualize the reasons that originate such extreme situations. Through the analysis of the information obtained from Scrum users, the research shows the possible reasons why selforganization and subtle control may not function as successfully as expected, and the negative consequences that this may have over the project. The findings also reflect how people understand and apply self-organization and subtle control and how they interpret and assume their roles along the process. Other relevant issues that have been remarked during the research are the Scrum Master's and team members' approaches to handle problems such as loss of authority and excessive intervention. Additionally, the outcome of the study shows that a solid introduction and lecturing of the Scrum theory and principles are equally important to avoid further risks. The results have revealed as well, the importance of an active, constant communication and commitment among all the roles involved in the project in order to keep away unnecessary conflicts and tensions. The summary and conclusions include a brief recount of what can be improved in order to prevent that extreme self-organization and excessive control happen or at least minimize their negative impact on the success of the project.

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