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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.
1

Accelerated testing of tidal turbine main bearing in a full scale nacelle test rig

Karikari-Boateng, Kwaku Ampea January 2016 (has links)
Tidal Energy is one of the growing renewable energy technologies that is aimed at tackling global energy challenges. The Horizontal Axis Tidal Turbine (HATT) is an in-stream Tidal Energy Converter (TEC) which extracts kinetic energy from tidal flows. These tidal turbines face many reliability challenges due to their complexity, harsh operating environment and low accessibility. One of the component contributing significantly to the reliability of a TEC is the bearing supporting the rotating shaft within the nacelle. The reliability assessment of this component is essential during the design process and before their eventual deployments. This work is describes shaft bearing reliability assessment procedures. In recent years, the Offshore Renewable Energy (ORE) Catapult’s National Renewable Energy Centre has developed a dedicated multi axis test facility for full scale testing of tidal turbine nacelles and components (i.e. Nautilus). This work presents a methodology for testing tidal turbine shaft bearings in a representative manner in the full scale nacelle test rig, Nautilus. Two aspects are considered, namely the damage assessment and the damage replication in an accelerated manner. The damage assessment process considers the global loading on the shaft bearing and a Rigid Dynamics (RD) model has been applied to identify the local bearing loads. Local loads are converted to stress enabling the identification of stress-life relationship and bearing damage. The damage replication process is aimed to evaluate the 20 year damage and the Acceleration by Phase-shift (AbP) method has been developed to accelerate the cumulative damage. The AbP method enables the assessment of performance characteristics of shaft bearings in a laboratory environment, reducing failure rates, validate performance in a cost effective manner by reduced testing times. Within this work, novel processes for shaft bearing reliability assessments and demonstration are suggested and it concludes with the presentation of a recommended test plan for carrying out accelerated tests on a full scale bearing.
2

A Test Planning System for Functional Validation of VHDL DSP Models

Lin, Morris Mengwei 04 February 1998 (has links)
Validating DSP circuits modeled in VHDL involves generating test data, creating VHDL test benches, and simulating the test benches including models under test (MUTs). This is a laborious and time-consuming process. Therefore, it is desirable to develop a high level approach to automating and planning these tasks. This dissertation presents a high level test planning system for functional validation of VHDL DSP models. The system requirements parameterized from the specifications constitute the input space and serve as generics of test benches. Library-based test benches are developed using high level design tools. A test planning framework uses a goal tree structure as a vehicle of planning and documenting the testing activities. In a goal tree, test goals are given based on the specifications and test groups are defined to satisfy the test goals. Test groups partially constrain the system requirements and thus partition the input space into smaller and more manageable subspaces. A set of test strategies are then applied to the test groups for efficient test case design. Each test case is mapped to a configuration declaration of the test bench. The test bench is then simulated to generate test vectors against which the MUT is tested. The MUT response is compared with the gold response by a comparator and verdicts are reached by test oracles. An integrated test planning software system has been developed for test planning and test automation based on this approach. As an illustration of this approach, this dissertation uses the Synthetic Aperture Radar system as a case study. Completeness and effectiveness of the generated test set are evaluated. This dissertation also discusses approaches to hierarchical faulty module isolation for hierarchical circuits. Exposability is proposed to measure the extent that signal values are revealed to the tester and is used as the cost function for the faulty module search problem. An expanded goal tree which explores the functional and structural aspects of a hierarchical circuit is also presented. / Ph. D.
3

A Multi-Language Goal-Tree Based Functional Test Planning System

Mahajan, Rajneesh 19 August 2002 (has links)
Test plans are used to guide, organize and document the testing activities during hardware design process. Manual test planning and configuration is known to be labor intensive, time consuming and error prone. It is desirable to develop efficient approaches to model testing and to develop test tools to automate test-planning activities. With the emergence of new hardware design paradigms, there is a need to develop more specialized description languages. However, adopting a new language for hardware-based designs involves adapting the existing design and verification tool suite for the new language. This is a very time consuming and capital intensive process. To ease the adoption of new description languages, it is desirable to develop multi-language support methodologies for design and test tools. This thesis addresses a subset of these problems. It presents a goal-tree based test methodology which is very effective for functional testing of hardware models in multiple application domains. Then it describes an approach for achieving a high degree of language independence using ideas of data abstraction. It also presents an automated test-planning tool called the "Goal Tree System (GTS)", which provides an implementation of goal tree methodology and multi-language support ideas. We demonstrate the use of this tool by testing models developed in VHDL and SystemC. We also present the design aspects of the Goal Tree System, which enable it to work across multiple platforms and with multiple simulators. / Master of Science
4

Advanced Data Analysis and Test Planning for Highly Reliable Products

Zhang, Ye January 2014 (has links)
Accelerated life testing (ALT) has been widely used in collecting failure time data of highly reliable products. Most parametric ALT models assume that the ALT data follows a specific probability distribution. However, the assumed distribution may not be adequate in describing the underlying failure time distribution. In this dissertation, a more generic method based on a phase-type distribution is presented to model ALT data. To estimate the parameters of such Erlang Coxian-based ALT models, both a mathematical programming approach and a maximum likelihood method are developed. To the best of our knowledge, this dissertation demonstrates, for the first time, the potential of using PH distributions for ALT data analysis. To shorten the test time of ALT, degradation tests have been studied as a useful alternative. Among many degradation tests, destructive degradation tests (DDT) have attracted much attention in reliability engineering. Moreover, some materials/products start degrading only after a random degradation initiation time that is often not even observable. In this dissertation, two-stage delayed-degradation models are developed to evaluate the reliability of a product with random initiation time. For homogeneous and heterogeneous populations, fixed-effects and random-effects Gamma processes are considered, respectively. An expectation-maximization algorithm and a bootstrap method are developed to facilitate the maximum likelihood estimation of model parameters and to construct the confidence intervals of the interested reliability index, respectively. With an Accelerated DDT model, an optimal test plan is presented to improve the statistical efficiency. In designing the ADDT experiment, decision variables related to the experiment must be determined under the constraints on limited resources, such as the number of test units and the total testing time. In this dissertation, the number of test units and stress level are pre-determined in planning an ADDT experiment. The goal is to improve the statistical efficiency by selecting appropriately allocate the test units to different stress levels to minimize the asymptotic variance of the estimator of the p-quantile of failure time. In particular, considering the random degradation initiation time, a three-level constant-stress destructive degradation test is studied. A mathematical programming problem is formulated to minimize the asymptotic variance of reliability estimate.
5

Měření propustnosti TCP/IP stacku v OS Linux / Measuring Throughput of TCP/IP stack in RedHat Linux

Okuliar, Adam January 2011 (has links)
Software testing is a process in which we try to check functionality and quality of tested software product. In this thesis we will discuss testing of Linux kernel in order to check up its functionality and performance of its network related part. We use our own metrics developed on standards, which describes testing of network active devices.
6

Stavebně technologický projekt objektu Vilaparku v Olomouci / Construction-technological project of the Vilapark building in Olomouc

Hladíková, Simona January 2020 (has links)
The assignment for the diplomatic work was mentioned in the technological project of the Vila Park in Olomouc. The task was to mention the underground floor of the 2nd dilatation and the building of the apartment house B7 with three floors, which is connected via the basement communication. The content of the technical report in the construction technology project, broader relationships, land-use planning, timeable, equipment design, machine assembly design, technological prescription of waterproof concrete construction, control and test plan, plan and item budget.
7

Pension ve Špindlerově Mlýně - stavebně technologický projekt / Guesthouse in Špindlerově Mlýně - construction technology project

Brychta, Ondřej January 2018 (has links)
THE OBJECTIVE OF THIS DIPLOMA WORK IS THE BUILDING-TECHNOLOGICAL PROJECT OF THE PENSION IN SPINDLER MILL. DIPLOMA WORK REALIZING GROWING LOWER BUILDINGS AND GROSS TOP STAYS OF THE PENSION OBJECT. DETAILS ARE DETAILED FOR THE MOST DEMANDED DESIGN OF MACHINERY, BUDGET BUDGET, TIME SCHEME, CONTROL AND TEST PLANS, BUILDING EQUIPMENT, DESIGNATION OF MOVING MECHANISM AND WIDER RELATIONSHIPS. THE DIPLOMA WORK IS PROCESSED ON THE BASIS OF THE TECHNICAL SIGNS PROVIDED BY THE PROJECTANT
8

Stavebně technologický projekt bytového domu v Miroslavi / Building technological project of Miroslav

Jedličková, Alena January 2018 (has links)
In this thesis there are main parts of the building and technological project of The apartment building Miroslav. There is technical report on on the technological project, studies of major technological stages, site equipment project, design of building machines and mechanisms, time plan, inspections and test plan.
9

Stavebně technologický projekt výstavby centrální nabíjecí stanice v Púchově / Construction-technological project for the construction of a central charging station in Púchov

Stopka, Peter January 2019 (has links)
This diploma thesis focuses on the construction of a construction technological project for the construction of the Central Charging Station in Púchov. The building is located in the industrial area of Púchov and in the area of Continental Matador Rubber. In the thesis is elaborated technical report for building technological project, co-ordination situation of construction with wider transport routes, time and financial object plan, study of the realization of the main technological stages, construction site design, design of main building machines and mechanisms, time schedule of main building, securing material resources for the monolithic part of the building. In the thesis are made, technological rules for drilled pilots and ceiling structure above the first overground floor. Technological regulations follow control and test plans. Other assignments that have been made in this work, such as the occupational safety and health plan, the design and comparison of cranes and the item budget.
10

Obchodní a administrativní centrum Poděbradská - stavebně technologický projekt / Poděbradská Commercial and Administrative Center - construction technology project

Kmeť, Peter January 2020 (has links)
This diploma thesis focuses on construction technology preparation of shopping center in Prague 9, Vysočany. The aim of this work was to choose an appropriate construction process. The thesis contains general information about construction with construction technology project, its financial and time consuming, facilities for construction and traffic situation in the surroundings of the construction, design of main machinery and mechanisms, technological regulation with control and test plan. The diploma thesis is focused on piles realization.

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