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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.
101

A facility for testing the aerodynamic and acoustic performance of bidirectional air turbines for ocean wave energy conversion

Moisel, Christoph, Carolus, Thomas 02 December 2019 (has links)
Bidirectional air turbines are used in oscillating water column (OWC) power plants for harnessing ocean wave energy. This paper describes the bidirectional aerodynamic and aero-acoustic facility at the University of Siegen for model air turbines performance testing. At least nine test facilities are known worldwide, but their layout, the performance testing procedure and the presentation of performance data are not standardized to this day. The layout of the facility at the University of Siegen follows ideas in ISO 5801 for fan performance testing. The pressurized air supply is bidirectional but steady-state. Achievable values of Reynolds and Mach number of the test turbines are 1,000,000 and 0.5, respectively. In addition, the facility is equipped with acoustic attenuators in the air supply for allowing synchronous determination of aerodynamic and acoustic characteristics of a turbine. A good practice guideline for turbine performance testing and presentation is proposed by showing full sets of non-dimensional aerodynamic and acoustic performance characteristics from two sample model turbines. Eventually, a comparison of in situ data from a full-scale turbine in transient operation with scaled up steady-state model performance measurements underlines the usefulness of steady-state model performance testing.
102

Stanovení výkonnostních norem pro testování na překážkové dráze CISM / Determination of efficiency standards of testing on the CISM obstacle course

Škobrtal, Michal January 2012 (has links)
Author's first name and surname: Michal Škobrtal Title of master gen thesis: Determination of efficiency standards of testing on the CISM obstacle course. Supervizor: PaedDr. Lubomír PŘÍVĚTIVÝ, CSc. Presentation year: 2012 Abstract Objective: To determine efficiency standards of physical performance testing of career soldiers of Armed Forces of the Czech Republic performed on the CISM obstacle course. Methods: Standardized testing and succesive determinantion of standards were used. Equivalent-interval scale which is characterized by constant measuring unit was also used. Due to this scale parametric methods were used to determination of standards: arithmetic average, determinative deviation and median. Results: The result of this thesis is a determination of performance standards of career soldiers of Czech Armed Forces for testing purposes while using CISM obstacle course. Standards are set for both men and women categories and for purpose of professional physical performance testing. These standards are provided in two variants. The first variant is specified for type A and B units and the second variant is specified for type C units. Standards for given category and variant are additionally divided according to dress and gear which is used during testing as follows:  BDU (battle dress uniform);  BDU,...
103

Cross-fertilizing formal approaches for protocol conformance and performance testing / Approches formelles croisées pour les tests de protocole de conformité et de performance

Che, Xiaoping 26 June 2014 (has links)
Les technologies de communication et les services web sont devenus disponibles dans notre vie numérique, les réseaux informatiques continuent de croître et de nouveaux protocoles de communication sont constamment définis et développés. Par la suite, la standardisation et la normalisation des protocoles sont dispensables pour permettre aux différents systèmes de dialoguer. Bien que ces normes peuvent être formellement vérifiés, les développeurs peuvent produire des erreurs conduisant à des implémentations défectueuses. C'est la raison pour laquelle leur mise en œuvre doit être strictement examinée. Cependant, la plupart des approches de tests actuels exigent une stimulation de l’exécution dans le cadre des tests (IUT). Si le système ne peut être consulté ou interrompu, l'IUT ne sera pas en mesure d'être testé. En outre, la plupart des travaux existants sont basées sur des modèles formels et très peu de travaux s'intéressent à la formalisation des exigences de performance. Pour résoudre ces problèmes, nous avons proposé une approche de test basé sur la logique "Horn" afin de tester passivement la conformité et la performance des protocoles. Dans notre approche, les exigences peuvent être formalisées avec précision. Ces exigences formelles sont également testées par des millions de messages collectés à partir des communicants réels. Les résultats satisfaisants des expériences effectuées ont prouvé le bon fonctionnement et l'efficacité de notre approche. Aussi pour satisfaire les besoins croissants de tests distribués en temps réel, nous avons également proposé un cadre de tests distribués et un cadre de tests en ligne et nous avons mis en œuvre notre plateforme dans un environnement réel à petite échelle avec succès / While today’s communications are essential and a huge set of services is available online, computer networks continue to grow and novel communication protocols are continuously being defined and developed. De facto, protocol standards are required to allow different systems to interwork. Though these standards can be formally verified, the developers may produce some errors leading to faulty implementations. That is the reason why their implementations must be strictly tested. However, most current testing approaches require a stimulation of the implementation under tests (IUT). If the system cannot be accessed or interrupted, the IUT will not be able to be tested. Besides, most of the existing works are based on formal models and quite few works study formalizing performance requirements. To solve these issues, we proposed a novel logic-based testing approach to test the protocol conformance and performance passively. In our approach, conformance and performance requirements can be accurately formalized using the Horn-Logic based syntax and semantics. These formalized requirements are also tested through millions of messages collected from real communicating environments. The satisfying results returned from the experiments proved the functionality and efficiency of our approach. Also for satisfying the increasing needs in real-time distributed testing, we also proposed a distributed testing framework and an online testing framework, and performed the frameworks in a real small scale environment. The preliminary results are obtained with success. And also, applying our approach under billions of messages and optimizing the algorithm will be our future works
104

Aerodynamic Load Characteristics Evaluation and Tri-Axial Performance Testing on Fiber Reinforced Polymer Connections and Metal Fasteners to Promote Hurricane Damage Mitigation

Canino-Vazquez, Iván R. 13 November 2009 (has links)
Damages during extreme wind events highlight the weaknesses of mechanical fasteners at the roof-to-wall connections in residential timber frame buildings. The allowable capacity of the metal fasteners is based on results of unidirectional component testing that do not simulate realistic tri-axial aerodynamic loading effects. The first objective of this research was to simulate hurricane effects and study hurricane-structure interaction at full-scale, facilitating better understanding of the combined impacts of wind, rain, and debris on inter-component connections at spatial and temporal scales. The second objective was to evaluate the performance of a non-intrusive roof-to-wall connection system using fiber reinforced polymer (FRP) materials and compare its load capacity to the capacity of an existing metal fastener under simulated aerodynamic loads. The Wall of Wind (WoW) testing performed using FRP connections on a one-story gable-roof timber structure instrumented with a variety of sensors, was used to create a database on aerodynamic and aero-hydrodynamic loading on roof-to-wall connections tested under several parameters: angles of attack, wind-turbulence content, internal pressure conditions, with and without effects of rain. Based on the aerodynamic loading results obtained from WoW tests, sets of three force components (tri-axial mean loads) were combined into a series of resultant mean forces, which were used to test the FRP and metal connections in the structures laboratory up to failure. A new component testing system and test protocol were developed for testing fasteners under simulated tri-axial loading as opposed to uni-axial loading. The tri-axial and uni-axial test results were compared for hurricane clips. Also, comparison was made between tri-axial load capacity of FRP and metal connections. The research findings demonstrate that the FRP connection is a viable option for use in timber roof-to-wall connection system. Findings also confirm that current testing methods of mechanical fasteners tend to overestimate the actual load capacities of a connector. Additionally, the research also contributes to the development a new testing protocol for fasteners using tri-axial simultaneous loads based on the aerodynamic database obtained from the WoW testing.
105

Webová aplikace zprostředkovávající výsledky testování výkonu platformy JBoss / Test Result Repository with Web User Interface

Vlasák, Jaroslav January 2013 (has links)
This thesis deals with the development of a client-server application for Red Hat company. Client participates in testing process of JBoss platform and gets user-defined performance data which sends during testing to the server application by platform independent communication. The server application allows to analyze the received data which can be also compared by several perspectives. These services for data analysis and comparison are accessible for server users using the web client. The server application supports the import of the performance data stored in the XML file and also their export for qVue portal. The client part of the application is implemented in Java and the server application is based on Java EE platform.
106

Vliv miniinvazivního přístupu na respirační funkce u pacientů po aortální náhradě / Impact of Minimally Invasive Approach on Pulmonary Function in Patients Undergoing Aortic Valve Replacement

Gofus, Ján January 2021 (has links)
of the dissertation Impact of minimally invasive approach on pulmonary function in patients undergoing aortic valve replacement MUDr. Ján Gofus The most common minimally invasive approach to aortic valve replacement is upper hemisternotomy, which has been implemented at our department, as well. Preserving the lower half of thoracic cage could lead to lower postoperative drop of pulmonary function, apart from other benefits. Nevertheless, publications on this topic are insufficient and controversial. Our aim was to perform a prospective randomized trial comparing upper hemisternotomy with standard (median) sternotomy in terms of pulmonary function changes perioperatively. We also added a novel exercise tolerance test, one-minute sit-to-stand test, and a quality of life evaluation to the study. We included patients indicated for elective isolated aortic valve replacement with bioprosthesis who were older than 65 years, signed informed consent, and in which both surgical approaches were technically feasible. Exclusion criteria were re-do surgery and concomitant cardiac surgery. Patients were randomized to minimally invasive and standard group in 1:1 ratio. On the day of admission, on the 7th postoperative day and 3 months postoperatively, the patients underwent pulmonary function testing and one-minute...
107

Prestandajämförelse mellan krypterade och okrypterade tidsseriedatabaser med IoT-baserad temperatur- och geopositionsdata / Performance Comparison between Encrypted and Unencrypted Time Series Databases with IoT-Based Temperature and Geolocation Data

Uzunel, Sinem, Xu, Joanna January 2024 (has links)
Internet of Things (IoT) är en växande teknologi som spelar en allt större roll i samhället. Den innefattar ett nätverk av internetanslutna enheter som samlar in och utbyter data. Samtidigt som IoT växer uppstår utmaningar kring hantering av stora datamängder och säkerhetsaspekter. Företaget Softhouse står inför utmaningen att välja en effektiv tidsseriedatabas för hantering av temperatur- och geopositionsdata från värmesystem i privata bostäder, där både prestanda och dataintegritet via kryptering är av stor vikt. Detta examensarbete har därför utfört en prestandajämförelse mellan AWSTimestream och InfluxDB, där olika tester har använts för att mäta exekveringstiden för inskrivning av sensordata och databasfrågor. Jämförelsen inkluderar AWS Timestream i krypterad form mot InfluxDB i dess AWS-molnversion i krypterad form, samt InfluxDB AWS i krypterad form mot InfluxDB i okrypterad form. Syftet med studien var att ge riktlinjer för valet av tidsseriedatabaser med fokus på prestanda och säkerhetsaspekter, inklusivekryptering. Studien undersökte även hur valet av rätt databas påverkar företag som Softhouse, både i termer av kvantitativa och kvalitativa fördelar, samt att ge en bedömning av kostnaderna. Resultatet visade att InfluxDB i dess AWS-molnversion generellt presterade bättre än AWS Timestream och InfluxDB i dess standardversion. Det fanns tydliga skillnader i prestanda mellan AWS Timestream och InfluxDB i dess AWS-molnversion, men inte lika tydliga skillnader i prestanda mellan InfluxDB i dess AWS-molnversion och standardversionen. Med hänsyn till både prestanda och säkerhet framstår InfluxDB i dess AWS-molnversion som det mest lämpliga alternativet. Det är emellertid av stor vikt att ta kostnadaspekten i beaktande, då AWS Timestream visar sig vara avsevärt mer kostnadseffektivt än InfluxDB. / The Internet of Things (IoT) is a growing technology that plays an increasingly significant role in society. It encompasses a network of internet-connected devices that collect and exchange data. As IoT continues to expand, challenges arise regarding the management of large volumes of data and security aspects. The company Softhouse faces the challenge of choosing an efficient time-series database for handling temperature and geoposition data from heating systems in homes, where both performance and data integrity through encryption are of great importance. Therefore, this thesis has conducted a performance comparison between AWS Timestream and InfluxDB, using various tests to measure the execution times for data ingestion of sensor data and database queries. The comparison includes AWS Timestream in encrypted form versus InfluxDB in its AWS cloud version in encrypted form, as well as InfluxDB AWS in encrypted form versus InfluxDB in unencrypted form. The aim of the study was to provide guidelines for the selection of time-series databases with a focus on performance and security aspects, including encryption. The study also explored how the choice of the right database affects companies like Softhouse, both in terms of quantitative and qualitative benefits, and provided an assessment of costs. The results showed that InfluxDB in its AWS cloud version generally outperformed AWS Timestream and InfluxDB in its standard version. There were clear performance differences between AWS Timestream and InfluxDB in its AWS cloud version, but not as pronounced differences in performance between InfluxDB in itsAWS cloud version and the standard version. Considering both performance and security, InfluxDB in its AWS cloud version appears to be the most suitable option. However, it is crucial to consider the cost aspect, as AWS Timestream proves to be significantly more cost-effective than InfluxDB.
108

Testverktyg för prestandamätningar av feta klienter : - En fallstudie med fokus på identifiering av testverktyg och beskrivning av viktiga kriterier för dessa / Testing tools for performance testing thick clients : – a case study with focus on identifying testing tools and describing important criteria for these

Stenberg, Maria January 2017 (has links)
Denna studie syftar till att beskriva prestandatest av feta klienter, ibland också kallade skrivbordsapplikationer. Studien syftar även till att kartlägga testverktyg som kan användas för att utföra prestandatest av feta klienter och att identifiera vilka egenskaper som anses vara viktiga kriterier för dessa testverktyg. Undersökningen är skapad som en fallstudie som undersökningsstrategi där fallets utgångspunkt är Trafikverkets behov men undersökning och dess resultat kan även appliceras på andra verksamheter där testarbete utförs. Både kvalitativ och kvantitativ datainsamling användes i undersökningen genom intervjuer och dokumentstudier samt enkätformulär. Då insamlat data i undersökningen är av både kvalitativ och kvantitativ form så användes också en blandning av en kvalitativ tematisk analys och kvantitativ dataanalys. En del av analysen är en utvärdering av ett testverktygsurval mot sammanställda kriterier, en kriteriebaserad utvärderingsmetod. Tillvägagångssättet för val och utvärdering av testverktyg som tillämpats genom studien är baserat på tidigare befintliga teorier som funnits genom litteraturstudier. Litteraturstudierna har även stått till grund för att definiera undersökningens centrala begrepp och bidrar till resultat genom en jämförelse med insamlat data. Resultatet från undersökningen bidrar med ett beslutsunderlag för verksamheter som står inför ett val av testverktyg för prestandatest av feta klienter och en utvärdering av dessa innan licenser införskaffas. Undersökningen bidrar även med en karakterisering av prestandatest av feta klienter. I just detta fall var de mest passande testverktygen för syftet HP LoadRunner samt två testverktyg från eggPlant i kombination (eggPlant Functional och eggPlant Performance). / The aim of this study is to describe performance testing on thick clients, sometimes also referred to as desktop applications. Another aim with this study is to map out a selection of testing tools that can be used for performance testing of thick clients and to identify what qualities that is considered to be important criteria for these testing tools. The study is based on the research strategy called case study where the case is grounded the needs from Trafikverket but the results from this study could be applied on other business organizations that works with testing. Both qualitative and quantitative data collecting methods where used in this study, in the form och interviews, document studies and questionnaires. Since the collected data in the study where in both qualitative and quantitative form the use of a mix between a qualitative thematical data analysis and a quantitative data analysis had to be done. A part of the analysis was an evaluation on a selection of testing tools towards a compiled list of criteria, as an evaluation method based on criteria. The course of action for choosing and evaluation a testing tool that has been applied throughout the study is based on preexisting theories that has been found through reviews of literature. The reviews of literature have also been the ground for defining the central concepts of the study and contributes to the result by comparing what’s been found in literature to the collected data. The result of the study contributes with a basis for decision for companies and organizations that is in the process of getting a testing tool for performance testing thick clients och how to evaluate these before obtaining the testing tool licenses. The study also contributes with a characterization of performance testing thick clients. In this particular case, the most suitable testing tools came to be HP LoadRunner and also two testing tools from eggPlant combined (eggPlant Functional and eggPlant Performance).
109

Zátěžové testování informačních systémů / Performance testing of information systems

Klaška, Jan January 2008 (has links)
This thesis if focused on performance, especially load testing of information systems. In the first part is defined software quality and reader is provided by fundamentals of software testing. Process of sofware testing is well described here. The rest of the paper is oriented on perfomance testing and it's processes and attributes. Specified are goals and principles of performance testing as well as types of performance tests and their purpose. Defined is load testing methodology including metrics for reliability and efficiency of information systems. Metrics are derived from well known international ISO standard 9126 - Software quality model. Methodology and metrics are validated during load test project on which author of this work participated. One chapter is also devoted to the tools used for load testing automatization. This paper is focused on the testing experts as well as on the other readers who want to acquire information on load testing, software efficiency or generally on testing of software quality.
110

Projekt vývoje Integrovaného testovacího nástroje / Project Development of Integrated Testing Node

Ženíšek, Jan January 2014 (has links)
Nowadays the development speed of new software products is a key to success and it is not important whether the aim is to make customer's urges satisfied or get ahead of one's competitors and fill the market gap. Because of the increase of development speed the demands on the saving process of software quality are increasing. There are two types of tools that are supporting the process of software quality assurance. Firstly, we talk about comprehensive testing tools of commercial character that usually include many functions, but their purchase is extremely expensive. On the other hand there are open-source tools that are available for free, they function on many kinds of operating systems and it is possible to modify them. Unfortunately their functions are basically focused on a certain subset of controlling the software quality assurance. Company TRASK solution a.s. has decided to change this current situation, so it asked competence centre Software Quality Assurance at the University of Economics in Prague in order to create Integrated Testing Node (ITN) that would combine the advantages of open-source tools. Moreover, it would offer broad range of functions as commercial solution. The purpose of this thesis is to describe relevant phases of the process of creating the Integrated Testing Node from the factual and methodical point of view. This aim is divided into partial aims included task analysis and the proposal of solving system, open-source products portfolio analysis, choice of the most convenient tools for following integration, choosing the method of information system building, evaluating the feedback from a client and the proposal of future development of this tool. As far as the biggest contribution of this thesis is concerned, it is the realisation of ITN project that can be used during information classes at the University of Economics in Prague. Furthermore, it can be used as the control of software quality in commercial companies.

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