30,401 research outputs found

    Determining the quality of mathematical software using reference data sets

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    This paper describes a methodology for evaluating the numerical accuracy of software that performs mathematical calculations. The authors explain how this methodology extends the concept of metrological traceability, which is fundamental to measurement, to include software quality. Overviews of two European Union-funded projects are also presented. The first project developed an infrastructure to allow software to be verified by testing, via the internet, using reference data sets. The primary focus of the project was software used within systems that make physical measurements. The second project, currently underway, explores using this infrastructure to verify mathematical software used within general scientific and engineering disciplines. Publications on using reference data sets for the verification of mathematical software are usually intended for a readership specialising in measurement science or mathematics. This paper is aimed at a more general readership, in particular software quality specialists and computer scientists. Further engagement with experts in these disciplines will be helpful to the continued development of this application of software quality

    Adoption of integrated cattle and oil palm farming system in Malaysia

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    Malaysian government had encouraged the adoption of integrated cattle and oil palm farming system (ICOFS) since the year 1998. This is due to large areas of land suitable for ICOFS in Malaysia that can be well utilised. Rising up the participation in ICOFS is one of the effort in facing the increasing demand of meat nationwide and growing dependency on imported meat. Apart from that, Malaysia needs to increase the self�sufficiency level of national meat production to 32.7% by 2020 as stated in the National Agri-Food Policy 2011-2020. Despite this, only a small number of farmers have adopted ICOFS in Malaysia and less is known so far about the farmer's attitudes towards the ICOFS in Malaysia. Therefore, this study aimed to explore the current practice as well as factors affecting and constraints to the adoption of ICOFS in Malaysia. Interviews of four selected experts in ICOFS were held to examine the current practice of ICOFS in Malaysia. Results from the interviews and literature review have been cross-compared to develop questionnaire instruments. Then, the survey questionnaire was carried out to 153 adopters and non-adopters of ICOFS in Johor, Malaysia to identify the key factors that influence the adoption of ICOFS. The study found that information and know-how and availability of skilled labour are the significant factors that encourage farmers to adopt ICOFS. On the other hand, government support and policy constraint and production and on-farm constraint are the significant constraints hindering the adoption of ICOFS. Based on the findings of this study, one of the measure to increase the rate of adoption of ICOFS are by helping the farmers to hire extra labour and to have skills needed. Furthermore, rate of ICOFS could also be increase by helping the farmers to have better control on weed, pest and diseases on farm as well as not interrupting their oil palm production. In addition, it is suggested to provide them with more opportunity towards incentives, training and technical support from the field officers. It is suggested for future research to explore the effect of factors affecting adoption and constraints to adoption on other attitudinal and psychological outcomes such as satisfaction, successfulness, involvement and degree of use

    Development of a novel virtual coordinate measuring machine

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    Existing VCMMs (virtual coordinate measuring machine) have been mainly developed to either simulate the measurement process hence enabling the off-line programming, or to perform error analysis and uncertainty evaluation. Their capability and performance could be greatly improved if there is a complete solution to cover the whole process and provide an integrated environment. The aim of this study is to develop such a VCMM that not only supports measurement process simulation, but also performs uncertainty evaluation. It makes use of virtual reality techniques to provide an accurate model of a physical CMM, together with uncertainty evaluation. An interface is also provided to communicate with CMM controller, allowing the measuring programs generated and simulated in the VCMM to be executed or tested on the physical CMM afterwards. This paper discusses the proposal of a novel VCMM design and the preliminary results

    Task‐specific measurement uncertainty budget of Curvic‐coupling using analytical methods

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    A number of Industrial reference components manufactured by grinding to achieve tight dimensional tolerances. In this paper, we present an uncertainty budget of a reference forty-tooth #Curvic measured using an accurate Coordinate Measuring Machine (CMM) in a temperature-controlled laboratory. A number of measurements conducted on Curvicto assess measurement repeatability and reproducibility. Expanded uncertainty budget evaluated from twenty-one Influencing factors, giving8.7 µm (7.1 µm from Type A) and 11 µm (9.6 µm from Type A), respectively, for repeatability and reproducibility test (k >2). Measurement uncertainty due to steady-state thermal effects is 2.2 µm. An adaptable model is presented to evaluate transient thermal effects, a factor often neglected in measurement uncertainty. Thermal time constant uncertainty associated with transient thermal effects is evaluated u(τ)= ±398 s, which corresponds to ±15 % of thermal time constant expanded uncertainty, u(τ)= ±2570 s. #Curvic® (Curvic is a trademark of The Gleason Works, 1000 University Avenue, Rochester, NY, 14603, USA

    application of process parameters in planning and technological documentation cnc machine tools and cmms programming perspective

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    Abstract This article focuses on the role and application of process parameters in technological process planning (TPP) and technological documentation (TD). The challenges and complexity involved in computer numerical control (CNC) machine tools and coordinate measuring machines (CMMs) programming have been taken into consideration with reference to the TD. The article presents the use of different programming platforms and implementation of them in technological process planning. The subtractive manufacturing and related measurements that are required during the TPP and TD phase have been taken into consideration. The findings and suggestions enable planners to incorporate the existing programming platforms and tools in the TPP and TD

    An interactive computer graphics based off-line AVAIL programming environment for coordinate measuring machines

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    Productivity can be increased by providing computer aided off-line program development environment to operate direct computer controlled Coordinate Measuring Machines (CMM). Such an environment not only results in reduced operational downtime of the CMM but also eliminates the need for the operators to learn and debug the complicated CMM programming language. An application software was developed to provide a computer based graphical environment for on-the-screen CMM inspection simulation and AVAIL part program development. A comprehensive, menu driven front-end was developed as a foundation for this software. Algorithms were designed and coded to read and interpret CAD software part design information in Initial Graphics Exchange Specifications (IGES) format. CMM inspection activities can be simulated on the displayed part using various menu options. All user simulation activities are captured and converted to an AVAIL part program, which can be downloaded to a CMM for physical inspection of the part. The output generated by execution of the AVAIL part program can be brought back to the software. Inspection reports can be generated from the output information for further analysis about accept/reject decisions

    Knowledge Capture in CMM Inspection Planning: Barriers and Challenges

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    Coordinate Measuring Machines (CMM) have been widely used as a means of evaluating product quality and controlling quality manufacturing processes. Many techniques have been developed to facilitate the generation of CMM measurement plans. However, there are major gaps in the understanding of planning such strategies. This significant lack of explicitly available knowledge on how experts prepare plans and carry out measurements slows down the planning process, leading to the repetitive reinvention of new plans while preventing the automation or even semi-automation of the process. The objectives of this paper are twofold: (i) to provide a review of the existing inspection planning systems and discuss the barriers and challenges, especially from the aspect of knowledge capture and formalization; and (ii) to propose and demonstrate a novel digital engineering mixed reality paradigm which has the potential to facilitate the rapid capture of implicit inspection knowledge and explicitly represent this in a formalized way. An outline and the results of the development of an early stage prototype - which will form the foundation of a more complex system to address the aforementioned technological challenges identified in the literature survey - will be given
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