9,130,653 research outputs found

    Development of the Integrated Model of the Automotive Product Quality Assessment

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    Issues on building an integrated model of the automotive product quality assessment are studied herein basing on widely applicable methods and models of the quality assessment. A conceptual model of the automotive product quality system meeting customer requirements has been developed. Typical characteristics of modern industrial production are an increase in the production dynamism that determines the product properties; a continuous increase in the volume of information required for decision-making, an increased role of knowledge and high technologies implementing absolutely new scientific and technical ideas. To solve the problem of increasing the automotive product quality, a conceptual structural and hierarchical model is offered to ensure its quality as a closed system with feedback between the regulatory, manufacturing, and information modules, responsible for formation of the product quality at all stages of its life cycle. The three module model of the system of the industrial product quality assurance is considered to be universal and to give the opportunity to explore processes of any complexity while solving theoretical and practical problems of the quality assessment and prediction for products for various purposes, including automotive

    Development of the Metal Rheology Model of High-temperature Deformation for Modeling by Finite Element Method

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    It is shown that when modeling the processes of forging and stamping, it is necessary to take into account not only the hardening of the material, but also softening, which occurs during hot processing. Otherwise, the power parameters of the deformation processes are precisely determined, which leads to the choice of more powerful equipment. Softening accounting (processes of stress relaxation) will allow to accurately determine the stress and strain state (SSS) of the workpiece, as well as the power parameters of the processes of deformation. This will expand the technological capabilities of these processes. Existing commercial software systems for modeling hot plastic deformations based on the finite element method (FEM) do not allow this. This is due to the absence in these software products of the communication model of the component deformation rates and stresses, which would take into account stress relaxation. As a result, on the basis of the Maxwell visco-elastic model, a relationship is established between deformation rates and stresses. The developed model allows to take into account the metal softening during a pause after hot deformation. The resulting mathematical model is tested by experiment on different steels at different temperatures of deformation. The process of steels softening is determined using plastometers. It is established experimentally that the model developed by 89 ... 93 % describes the rheology of the metal during hot deformation. The relationship between the components of the deformation rates and stresses is established, which allows to obtain a direct numerical solution of plastic deformation problems without FED iterative procedures, taking into account the real properties of the metal during deformation. As a result, the number of iterations and calculations has significantly decreased

    Development of Moisture Prediction Model for Tea using Electrical Impedance Spectroscopy

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    Moisture is the most essential parameter for tea leaves for storage and consumption stage as it affects the physical and chemical aspects of tea leaves with which it relates the stability and freshness the tea leaves for a long time. The most essential parameter which affects the quality of tea leaves is moisture for post harvesting, processing, storage and transport. The main aim of this study is to development procedure for moisture content measurements of fresh tea leaves using measurement acquired by electrical properties. Method This relation is obtained the frequency range within between 100 kHz to 300 MHz and moisture content ranges between 2%-75%. A good relation between moisture content and correlate with variations in electrical properties viz. IZI, Ѳz, R, Cp, Cs has been observed by partial least square regression technique. Result Moisture prediction model was developed by applying electrical properties and that the new technique it was observed more accuracy obtained using a single parameter as compared with that moisture measurement. Conclusion the model which is developed can evaluated with in performance the moisture content a commercial moisture meter which is expected

    Rectenna thermal model development

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    Deploying rectennas in space requires adapting existing designs developed for terrestrial applications to the space environment. One of the major issues in doing so is to understand the thermal performance of existing designs in the space environment. Toward that end, a 3D rectenna thermal model has been developed, which involves analyzing shorted rectenna elements and finite size rectenna element arrays. A shorted rectenna element is a single element whose ends are connected together by a material of negligible thermal resistance. A shorted element is a good approximation to a central element of a large array. This model has been applied to Brown's 2.45 GHz rectenna design. Results indicate that Brown's rectenna requires redesign or some means of enhancing the heat dissipation in order for the diode temperature to be maintained below 200 C above an output power density of 620 W/sq.m. The model developed in this paper is very general and can be used for the analysis and design of any type of rectenna design of any frequency

    Work Journey Rescheduling – Model Development Analysis.

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    Using Wakefield as a case study, a method was developed of testing the effects on traffic of several different work journey rescheduling strategies. The method consisted essentially of assigning a series of six 0-D matrices to the Wakefield network, each matrix representing the trips for consecutive 15 minute periods over the morning peak. The six matrices were obtained by firstly disaggregating the l 1/2 hr peak matrix by purpose (into home-based work, commercial vehicle, and other trips) and then disaggregating each of these three matrices by time. This temporal disaggregation was based, for the home based work trips, on employee arrival profiles by zone, and for the CV and other trips on cordon crossing profiles. The different strategies were modelled by making adjustments to the parameters of the employee arrival profiles. Other relevant papers in this series are WP 150 Work Journey Rescheduling : Report of Surveys, and WP 168 Work Journey Reschediuling : Results and conclusions

    Reliability prediction in model driven development

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    Evaluating the implications of an architecture design early in the software development lifecycle is important in order to reduce costs of development. Reliability is an important concern with regard to the correct delivery of software system service. Recently, the UML Profile for Modeling Quality of Service has defined a set of UML extensions to represent dependability concerns (including reliability) and other non-functional requirements in early stages of the software development lifecycle. Our research has shown that these extensions are not comprehensive enough to support reliability analysis for model-driven software engineering, because the description of reliability characteristics in this profile lacks support for certain dynamic aspects that are essential in modeling reliability. In this work, we define a profile for reliability analysis by extending the UML 2.0 specification to support reliability prediction based on scenario specifications. A UML model specified using the profile is translated to a labelled transition system (LTS), which is used for automated reliability prediction and identification of implied scenarios; the results of this analysis are then fed back to the UML model. The result is a comprehensive framework for addressing software reliability modeling, including analysis and evolution of reliability predictions. We exemplify our approach using the Boiler System used in previous work and demonstrate how reliability analysis results can be integrated into UML models
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