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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.
31

Implementering av händelsedrivenarkitektur och händelsekällor för hälsodata / Implementation of event driven architecture and event sourcing for health data

Karlström, Kasper, Dewitsegid, Samsom January 2024 (has links)
Dagens hälso- och sjukvårdssystem är byggda som en traditionell monolit men det finns fler sätt att utveckla dessa system på. Händelsedriven arkitektur med händel-sekällor för lagring av data är ett modernt sätt att utveckla system. Syftet med det här arbetet är att undersöka om den modernare arkitekturen skulle kunna vara lämpligt och säkert alternativ för hälso- och sjukvårdssystem. För att undersöka detta gjordes en litteraturstudie inom relevanta områden som händelsedriven arki-tektur, händelsekällor, mikrotjänster och monolitiska system. Resultatet ifrån litteraturstudien gav att det finns andra beprövade koncept från andra problemområden, så som säker kommunikation och säker lagring med spår-barhet, som om de användes med händelsedriven arkitektur skulle uppnå kraven för hälsosektorn. Forskningsfrågan kan besvaras positivt baserat på den genomförda lit-teraturstudien. Därtill utvecklades en enkel prototyp, som utan att innehålla säker-hetsaspekter, gör det lätt att observera för och nackdelar med händelsedrivna lös-ningar jämfört med exempelvis traditionella monolitiska lösningar. / Today's healthcare systems are built as a traditional monolith, but there are more ways to develop these systems. Event driven architecture with event sourcing for sto-ring data is a modern way of developing systems. The purpose of this work is to in-vestigate whether the more modern architecture could be a suitable and safe alter-native for healthcare systems. To investigate this, a literature study was conducted in relevant areas such as event driven architecture, event sources, microservices and monolithic systems. The result of the literature study showed that there are other proven concepts from other problem areas, such as secure communication and secure storage with tracea-bility, which if used with event driven architecture would meet the requirements of the health sector. The research question can be answered positively based on the completed literature study. In addition, a simple prototype was developed, which, without containing security aspects, makes it easy to observe the pros and cons of event driven solutions compared to, for example, traditional monolithic solutions.
32

Comparison between CRUD and CQRS in an event driven system / Jämförelse mellan CRUD och CQRS i ett event drivet system

Jansson, Rasmus January 2024 (has links)
In todays digitalised society, effective solutions to manage huge amount of data is needed. An established design pattern that are used in many systems are CRUD. To handle data in events have become more popular over the years, but CRUD is not optimised for it. A possible replacement is CQRS, it is designed with events in mind. The purpose of the report is to see if CQRS can replace CRUD. The report shows that when it comes to an event driven system using event sourcing, CQRS is recommended. Reason being CQRS is more compatible with events then CRUD. CRUD is more designed around data driven design and therefor is a better fit for other systems. / I dagens digitaliserade samhälle krävs effektiva lösningar för att behandla stora mängder data. Ett etablerat designmönster som används i många system är CRUD. Att hantera data i händelser är något som har blivit alltmer populärt, men CRUD är inte optimerad kring just det. En möjlig ersättare är CQRS, som är designad med event i åtanke. Målet med denna rapport är att se om CQRS kan ersätta CRUD i ett händelsebaserat system. Rapporten visar att när det kommer till ett händelsedrivet system som använder händelsekällor, så är rekommendationen att använda CQRS. Detta för att CQRS är mer kompatibel med händelser än CRUD. CRUD är mer designat runt data driven design och funkar därför bättre med andra typer av system.
33

Event-Driven Dynamic Query Model for Sleep Study Outcomes Research

Jain, Sulabh 30 January 2012 (has links)
No description available.
34

Analyzing the Efficiency of Event-Driven APIs : A Potential Development in Government Information Systems

Backan, Karl January 2024 (has links)
Detta projekt utforskar effektiviteten hos händelsestyrda API:er, med fokus på Bolagsverket. Med ett ökande behov av realtids- och responsiva system blir traditionella datapollningsmetoder otillräckliga. Projektet utvärderar händelsestyrda arkitekturer (EDA) och deras potentiella fördelar genom att jämföra MQTT, WebSocket och det befintliga SFTPprotokollet hos Bolagsverket baserat på olika prestandamått. Projektresultaten visar att MQTT och WebSocket erbjuder förbättringar i responsivitet och resursutnyttjande, vilket tyder på att deras implementering kan förbättra operativ effektivitet vid Bolagsverket. Resultaten stödjer en övergång mot mer dynamiska, händelsestyrda lösningar. / This project explores the efficiency of event-driven APIs, focusing on Bolagsverket (the Swedish Companies Registration Office). With an increasing need for real-time, responsive systems, traditional data polling methods are becoming insufficient. This project evaluates event-driven architectures (EDA) and their potential benefits, comparing MQTT, WebSocket, and the existing SFTP protocol with Bolagsverket based on various performance metrics. The project results demonstrate that MQTT and WebSocket offer improvements in responsiveness and resource utilization, suggesting their implementation could enhance operational efficiency at Bolagsverket. The findings support a transition towards more dynamic, event-driven solutions.
35

Analyse et commande sans modèle de quadrotors avec comparaisons / Quadrotor analysis and model free control with comparisons

Wang, Jing 25 November 2013 (has links)
Inspiré par les limitations de contrôleurs PID traditionnels et les différentes performances dans les cas idéals et réalistes, les quadrotors existants, leurs applications et leurs méthodes de contrôle ont été intensivement étudiés dans cette thèse. De nombreux challenges sont dévoilés: les systèmes embarqués ont des limites des ressources de calcul et de l'énergie; la dynamique est assez complexe et souvent mal connu; l'environnement a beaucoup de perturbations et d'incertitudes; de nombreuses méthodes de contrôle ont été proposées dans des scénarios idéaux dans la littérature sans comparaison avec d’autres méthodes. Par conséquent, cette thèse porte sur ces principaux points dans le contrôle de quadrotors.Tout d'abord, les modèles cinématiques et dynamiques sont proposés, y compris toutes les forces et couples aérodynamiques importants. Un modèle dynamique simplifié est également proposé pour certaines applications. Ensuite, la dynamique de quadrotor est analysée. En utilisant la théorie de la forme normale, le modèle de quadrotor est simplifié à une forme plus simple nommée la forme normale, qui présente toutes les propriétés dynamiques possibles du système d'origine. Les bifurcations de cette forme normale sont étudiées, et le système est simplifié à son point de bifurcation en utilisant la théorie de la variété du centre. Basé sur l’étude des applications de quadrotors, cinq scénarios réalistes sont proposés : un cas idéal, les cas avec la perturbation du vent, les incertitudes des paramètres, les bruits de capteurs et les fautes de moteur. Ces cas réalistes peuvent montrer plus globalement les performances des méthodes de contrôle par rapport aux cas idéaux. Un schéma déclenché par événements est également proposé avec le schéma déclenché par. Ensuite, la commande sans modèle est présentée, Il s'agit d'une technique simple mais efficace pour la dynamique non-linéaire, inconnue ou partiellement connue. La commande par backstepping et la commande par mode glissant sont également proposées pour la comparaison.Toutes les méthodes de contrôle sont mises en œuvre sous les schémas déclenchés par temps et par événements dans cinq scénarios différents. Basé sur l’étude des applications de quadrotors, dix critères sont choisis pour évaluer les performances des méthodes de contrôle, telles que l'erreur maximale absolue de suivi, la variance de l'erreur, le nombre d’actionnement, la consommation d'énergie, etc. / Inspired by the limitations of traditional PID controllers and the different performance in ideal and realistic cases, the existing quadrotors, their applications and control methods have been intensively studied in this dissertation. Many challenges are shown: embedded quadrotor systems have limit computational resources and energy; the aerodynamic dynamics is rather complex and poorly known; environment has many disturbances and uncertainties; many control methods have been proposed in ideal scenarios in literature without comparison. Therefore, this dissertation focuses on these main points in control of quadrotors.A kinematic model and a dynamic model are proposed, including all the important aerodynamic forces and moments. A simplified dynamic model is also given based on some applications. Then, the dynamics of quadrotor is analyzed. Using the normal form theory, the model of quadrotor is simplified to a simplest form named the normal form, which exhibits all possible dynamic properties of the original system. The bifurcations of its normal form are then studied, and the system can be further simplified at its bifurcation point using the center manifold theory.Based on the research of the applications in the first chapter, five typical realistic scenarios are proposed: an ideal case, the cases with wind disturbance, parameter uncertainties, sensor noises and actuator faults. These realistic cases can show comprehensively the performance of control methods respect to the ideal cases. An event triggered scheme is also proposed with the time triggered scheme in order to further save computational resources. Then, a newly proposed method the model free control is presented. It is a simple but efficient technique for the nonlinear, unknown or partially known dynamics. A backstepping control and a sliding mode control are also proposed for the sake of comparison.All the control methods are implemented in the time and event triggered schemes in five different scenarios. In order to keep closer to realistic situations, the control gains of each methods are not changed in different scenarios. Based on the study in the first chapter, ten criteria are chosen for measuring the performance of control methods, such as the maximum absolute tracking error, the error variance, the actuation steps, the energy consumption, etc.
36

Simulering av miljoner grindar med Count Algoritmen / The Counting Algorithm for simulation of million-gate designs

Arvidsson, Klas January 2004 (has links)
<p>A key part in the development and verification of digital systems is simulation. But hardware simulators are expensive, and software simulation is not fast enough for designs with a large number of gates. As today’s digital zesigns constantly grow in size (number of gates), and that trend shows no signs to end, faster simulators handling millions of gates are needed. </p><p>We investigate how to create a software gate-level simulator able to simulate a high number of gates fast. This involves a trade-off between memory requirement and speed. A compact netlist representation can utilize cache memories more efficient but requires more work to interpret, while high memory requirements can limit the performance to the speed of main memory. </p><p>We have selected the Counting Algorithm to implement the experimental simulator MICA. The main reasons for this choice is the compact way in which gates can be stored, but still be evaluated in a simple and standard way. </p><p>The report describes the issues and solutions encountered and evaluate the resulting simulator. MICA simulates a SPARC architecture processor called Leon. Larger netlists are achieved by simulating several instances of this processor. Simulation of 128 instances is done at a speed of 9 million gates per second using only 3.5MB memory. In MICA this design correspond to 2.5 million gates.</p>
37

A Continuous-Time ADC and DSP for Smart Dust

Chhetri, Dhurv, Manyam, Venkata Narasimha January 2011 (has links)
Recently, smart dust or wireless sensor networks are gaining more attention.These autonomous, ultra-low power sensor-based electronic devices sense and process burst-type environmental variations and pass the data from one node (mote) to another in an ad-hoc network. Subsystems for smart dust are typically the analog interface (AI), analog-to-digital converter (ADC), digital signal processor (DSP), digital-to-analog converter (DAC), power management, and transceiver for communication. This thesis project describes an event-driven (ED) digital signal processing system (ADC, DSP and DAC) operating in continuous-time (CT) with smart dust as the target application. The benefits of the CT system compared to its conventional counterpart are lower in-band quantization noise and no requirement of a clock generator and anti-aliasing filter, which makes it suitable for processing burst-type data signals. A clockless EDADC system based on a CT delta modulation (DM) technique is presented. The ADC output is digital data, continuous in time, known as “data token”. The ADC employs an unbuffered, area efficient, segmented resistor-string (R-string) feedback DAC. A study of different segmented R-string DAC architectures is presented. A comparison in component reduction with prior art shows nearly 87.5% reduction of resistors and switches in the DAC and the D flip-flops in the bidirectional shift registers for an 8-bit ADC, utilizing the proposed segmented DAC architecture. The obtained SNDR for the 3-bit, 4-bit and 8-bit ADC system is 22.696 dB, 30.435 dB and 55.73 dB, respectively, with the band of interest as 220.5 kHz. The CTDSP operates asynchronously and process the data token obtained from the EDADC. A clockless transversal direct-form finite impulse response (FIR) low-pass filter (LPF) is designed. Systematic top-down test-driven methodology is employed through out the project. Initially, MATLAB models are used to compare the CT systems with the sampled systems. The complete CTDSP system is implemented in Cadence design environment. The thesis has resulted in two conference contributions. One for the 20th European Conference on Circuit Theory and Design, ECCTD’11 and the other for the 19th IFIP/IEEE International Conference on Very Large Scale Integration, VLSI-SoC’11. We obtained the second-best student paper award at the ECCTD.
38

Rule-based In-network Processing For Event-driven Applications In Wireless Sensor Networks

Sanli, Ozgur 01 June 2011 (has links) (PDF)
Wireless sensor networks are application-specific networks that necessitate the development of specific network and information processing architectures that can meet the requirements of the applications involved. The most important challenge related to wireless sensor networks is the limited energy and computational resources of the battery powered sensor nodes. Although the central processing of information produces the most accurate results, it is not an energy-efficient method because it requires a continuous flow of raw sensor readings over the network. As communication operations are the most expensive in terms of energy usage, the distributed processing of information is indispensable for viable deployments of applications in wireless sensor networks. This method not only helps in reducing the total amount of packets transmitted and the total energy consumed by sensor nodes, but also produces scalable and fault-tolerant networks. Another important challenge associated with wireless sensor networks is that the possibility of sensory data being imperfect and imprecise is high. The requirement of precision necessitates employing expensive mechanisms such as redundancy or use of sophisticated equipments. Therefore, approximate computing may need to be used instead of precise computing to conserve energy. This thesis presents two schemes that distribute information processing for event-driven reactive applications, which are interested in higher-level information not in the raw sensory data of individual nodes, to appropriate nodes in sensor networks. Furthermore, based on these schemes, a fuzzy rule-based system is proposed that handles imprecision, inherently present in sensory data.
39

Characterisation and Analysis of a Vibro-fluidised Granular Material

Sunthar, P 03 1900 (has links)
The present work is concerned with the mathematical modelling of a bed of granular material in a gravitational field vertically fluidised by a vibrating surface. The particles are in rapid motion, and lose energy by inelastic collisions. The steady state is maintained by a balance of the rate of dissipation of energy in inelastic particle collisions and the rate of transfer of energy due to particle collisions with the vibrating surface. The limit where the energy dissipation due to inelastic collisions is small compared to the mean kinetic energy of the particles is considered. This non-equilibrium steady state is similar to a dilute gas at equilibrium with a uniform temperature and an exponentially decaying density, obtained from the ideal gas equation of state. From the analysis of this state, four non-dimensional numbers are derived which uniquely specify the state of the system. A perturbative analysis about the uniform temperature state is carried out and analytical solutions to the macroscopic variables of the system are obtained using two types of approximations. The first is a hydrodynamic model using constitutive relations from the general kinetic theory of granular media, and the second is a kinetic theory formulation derived exclusively for the vibro-fluidised bed. The latter permits an anisotropy between the horizontal and vertical directions due to the anisotropic nature of the source of energy at the bottom wall. The kinetic theory is extended to incorporate the corrections due to the high density effects, which is similar to the Enskog correction to dense gases. An event driven (ED), or hard sphere molecular dynamic (MD), simulation of the vibrated bed is carried out. The quantitative predictions of the theories are validated by the simulation. A systematic probing of the parameter space within the ED simulations revealed two new phenomena in a vibro-fluidised bed which are inhomogeneous in the horizontal direction. These are convection rolls similar to the Rayleigh-Benard instability in fluids, and a clustering instability leading to a phase separation. The instabilities are characterised using a phase diagram. The homogeneous states close to these new states are adequately described by the models developed here. An analysis of the stability of this state could have implications in understanding the instabilities in driven granular materials (such as in sheared media and fluidised beds) in general, and pattern formation in vibrated beds in particular.
40

Įvykiais grindžiamų informacinių sistemų modeliavimo ir realizavimo metodika / Methodology for modelling and implementation of event-driven information systems

Rudaitis, Gediminas 28 January 2008 (has links)
Pastaruoju metu informacinių technologijų pasaulyje dažnai minimos paslaugomis ir įvykiais grindžiamų sistemų architektūros. Greitai besikeičiančiame verslo pasaulyje įmonėms yra aktualu turėti sistemas, kurios greitai ir lengvai būtų priderintos prie besikeičiančių verslo procesų ir sumažintų tokių sistemų kūrimo ir palaikymo išlaidas. Naudodamos paslaugomis grindžiamą architektūrą, įmonės gali lanksčiai tvarkyti savo veiklą ir kurti sistemas, nekeisdamos turimos techninės ar programinės įrangos. Nors literatūroje yra gausu straipsnių apie įvykiais grindžiamas sistemas ir jų privalumus, tačiau sistemos architektui, nusprendusiam sukurti įvykiais grindžiamos sistemos projektą, iškyla aktualus klausimas: kaip aprašyti ir modeliuoti įvykius, kurie ateina iš išorės arba sugeneruojami pačios sistemos ar vartotojų veiksmų su sistema metu. Akivaizdu, kad šiuo metu nėra populiarios metodikos, kuri apibrėžtų, kaip reikia atlikti įvykių modeliavimą ir jį panaudoti informacinių sistemų kūrimo procese. Šiame darbe nagrinėjami įvykiais grindžiamų sistemų modeliavimo metodai ir realizavimo technologijos. Atsižvelgiant į analizės rezultatus pateikiama įvykiais grindžiamų sistemų modeliavimo ir realizavimo metodika. Ši metodika pritaikyta ir įvertinta sukuriant publikacijų portalo prototipą. / Nowadays the terms SOA (Service Oriented Architecture) and event driven systems are often used when talking about systems with large scalability, performance and interoperability. In fast changing business world it is vital to have systems that could be easily changed whenever new functionality is needed. Using service oriented architecture companies can easier adapt its business process to changed business rules. Even though there are a lot of articles and publications about event driven systems and their advantages, but the system architect who decides to build an event driven system is facing the problem: how to model and describe events of the system. Obviously, that there are no popular and widely accepted methodology for event driven system modelling. The goal of this work is to develop a methodology for modelling an event driven systems. This methodology describes the metamodel for event modelling and the usage of the event model in system development life cycle. The developed methodology for modelling and implementation of event-driven information systems was used for making a model of publications portal prototype. Usage of this methodology in system design process adds more clarity, because all the events, which can be generated in the system and their types, are described in one diagram – event model. The event model elements can be used in other model diagrams, such as sequence or state machine diagrams.

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