1,078,020 research outputs found

    Axiomatic Testing of Structure Metrics

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    Axiomatic testing of software metrics is described, based on axioms from representational measurement theory. In a case study, the axioms are given for the formal relational structure and the empirical relational structure. Two approaches to axiomatic testing are elaborated: deterministic testing and probabilistic testin

    Fluid-Structure Interaction Simulation of a Coriolis Mass Flowmeter using a Lattice Boltzmann Method

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    In this paper we use a fluid-structure interaction (FSI) approach to simulate a Coriolis mass flowmeter (CMF). The fluid dynamics are calculated by the open source framework OpenLB, based on the lattice Boltzmann method (LBM). For the structural dynamics we employ the open source software Elmer, an implementation of the finite element method (FEM). A staggered coupling approach between the two software packages is presented. The finite element mesh is created by the mesh generator Gmsh to ensure a complete open source workflow. The Eigenmodes of the CMF, which are calculated by modal analysis are compared with measurement data. Using the estimated excitation frequency, a fully coupled, partitioned, FSI simulation is applied to simulate the phase shift of the investigated CMF design. The calculated phaseshift values are in good agreement to the measurement data and verify the suitability of the model to numerically describe the working principle of a CMF

    Rocket experiments for spectral estimation of electron density fine structure in the auroral and equatorial ionosphere and preliminary results

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    Sounding rockets equipped to monitor electron density and its fine structure were launched into the auroral and equatorial ionosphere in 1980 and 1983, respectively. The measurement electronics are based on the Langmuir probe and are described in detail. An approach to the spectral analysis of the density irregularities is addressed and a software algorithm implementing the approach is given. Preliminary results of the analysis are presented

    Empirical research on the evaluation model and method of sustainability of the open source ecosystem

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    The development of open source brings new thinking and production modes to software engineering and computer science, and establishes a software development method and ecological environment in which groups participate. Regardless of investors, developers, participants, and managers, they are most concerned about whether the Open Source Ecosystem can be sustainable to ensure that the ecosystem they choose will serve users for a long time. Moreover, the most important quality of the software ecosystem is sustainability, and it is also a research area in Symmetry. Therefore, it is significant to assess the sustainability of the Open Source Ecosystem. However, the current measurement of the sustainability of the Open Source Ecosystem lacks universal measurement indicators, as well as a method and a model. Therefore, this paper constructs an Evaluation Indicators System, which consists of three levels: The target level, the guideline level and the evaluation level, and takes openness, stability, activity, and extensibility as measurement indicators. On this basis, a weight calculation method, based on information contribution values and a Sustainability Assessment Model, is proposed. The models and methods are used to analyze the factors affecting the sustainability of Stack Overflow (SO) ecosystem. Through the analysis, we find that every indicator in the SO ecosystem is partaking in different development trends. The development trend of a single indicator does not represent the sustainable development trend of the whole ecosystem. It is necessary to consider all of the indicators to judge that ecosystem’s sustainability. The research on the sustainability of the Open Source Ecosystem is helpful for judging software health, measuring development efficiency and adjusting organizational structure. It also provides a reference for researchers who study the sustainability of software engineering

    Automated software quality visualisation using fuzzy logic techniques

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    In the past decade there has been a concerted effort by the software industry to improve the quality of its products. This has led to the inception of various techniques with which to control and measure the process involved in software development. Methods like the Capability Maturity Model have introduced processes and strategies that require measurement in the form of software metrics. With the ever increasing number of software metrics being introduced by capability based processes, software development organisations are finding it more difficult to understand and interpret metric scores. This is particularly problematic for senior management and project managers where analysis of the actual data is not feasible. This paper proposes a method with which to visually represent metric scores so that managers can easily see how their organisation is performing relative to quality goals set for each type of metric. Acting primarily as a proof of concept and prototype, we suggest ways in which real customer needs can be translated into a feasible technical solution. The solution itself visualises metric scores in the form of a tree structure and utilises Fuzzy Logic techniques, XGMML, Web Services and the .NET Framework. Future work is proposed to extend the system from the prototype stage and to overcome a problem with the masking of poor scores

    Assurance Cases in Model-Driven Development of the Pacemaker Software

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    We discuss the construction of an assurance case for the pace-maker software. The software is developed following a model-based technique that combined formal modeling of the system, systematic code generation from the formal model, and measurement of timing behavior of the implementation. We show how the structure of the assurance case reflects our development approach

    The Development of a Vision-Based Vibration Measurement System for Characterizing Civil Structures

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    Photogrammetry is one of the most promising non-contact, vision-based measuring techniques. It became commercially available as a result of the development of digital cameras and computer processing technology. Vision-based technique has wide applications in civil engineering such as deflection measurement or condition inspection. However, these applications focus more on static measurements because of the limitations of the acquisition frame rate and the resolution of the image sensor. Developing measurement systems using newly developed equipments and software can enable this technique to be applied to more fields. In this project, a vision-based vibration measurement system for characterizing civil structures is developed under LabVIEW environment. The major apparatus include two recently released machine vision cameras (Basler acA2040-180kc) with high resolution (4M pixels) and frame rate (180Hz), and a Camera Link image acquisition board (NI PXIe-1435). First, the test structure is modeled in 3-D by a photogrammetric software called PhotoModeler. Second, the measurement locations are determined by the dynamic characteristic of the structure. Then consecutive pictures of the test structure are taken and sent to the LabVIEW program to obtain the vibration data. At last the measured parameters are compared to the measurements of contact sensors. The results show that the obtained parameters are comparable to the contact measurements. In conclusion, photogrammetry is a considerably accurate non-contact measuring method. This project mainly focuses on the measurement part and the analysis of the acquired data is left for future study
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