159,600 research outputs found

    Model-based observer proposal for surface roughness monitoring

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    ComunicaciĂłn presentada a MESIC 2019 8th Manufacturing Engineering Society International Conference (Madrid, 19-21 de Junio de 2019)In the literature, many different machining monitoring systems for surface roughness and tool condition have been proposed and validated experimentally. However, these approaches commonly require costly equipment and experimentation. In this paper, we propose an alternative monitoring system for surface roughness based on a model-based observer considering simple relationships between tool wear, power consumption and surface roughness. The system estimates the surface roughness according to simple models and updates the estimation fusing the information from quality inspection and power consumption. This monitoring strategy is aligned with the industry 4.0 practices and promotes the fusion of data at different shop-floor levels

    Technical Efficiency in Organic Farming: an Application on Italian Cereal Farms using a Parametric Approach

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    A stochastic frontier production model was applied to estimate technical efficiency in a sample of Italian organic and conventional cereal farms. The main purpose was to assess which production technique revealed higher efficiency. Statistical tests on the pool sample model suggested that differences between the two cultivation methods were significant from a technological viewpoint. Separate analyses of two sub-samples (93 and 138 observations for organic and conventional farms, respectively) found that conventional farms were significantly more efficient than organic farms, with respect to their specific technology (0.892 vs. 0.825). This implies that organic (conventional) cereal farmers could increase their income to 99.19 €/ha (40.95 €/ha). Analysis also estimated that land was the technical input with the highest elasticity for both technologies. Furthermore, findings indicated that 63.7% of the differentials between observed and best-practice output was explained by technical inefficiency for the conventional group, while this value was close to unity for organic farms. Some policy implications can be drawn from these findings

    Estimating, planning and managing Agile Web development projects under a value-based perspective

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    Context: The processes of estimating, planning and managing are crucial for software development projects, since the results must be related to several business strategies. The broad expansion of the Internet and the global and interconnected economy make Web development projects be often characterized by expressions like delivering as soon as possible, reducing time to market and adapting to undefined requirements. In this kind of environment, traditional methodologies based on predictive techniques sometimes do not offer very satisfactory results. The rise of Agile methodologies and practices has provided some useful tools that, combined with Web Engineering techniques, can help to establish a framework to estimate, manage and plan Web development projects. Objective: This paper presents a proposal for estimating, planning and managing Web projects, by combining some existing Agile techniques with Web Engineering principles, presenting them as an unified framework which uses the business value to guide the delivery of features. Method: The proposal is analyzed by means of a case study, including a real-life project, in order to obtain relevant conclusions. Results: The results achieved after using the framework in a development project are presented, including interesting results on project planning and estimation, as well as on team productivity throughout the project. Conclusion: It is concluded that the framework can be useful in order to better manage Web-based projects, through a continuous value-based estimation and management process.Ministerio de EconomĂ­a y Competitividad TIN2013-46928-C3-3-

    Benefits of Protecting Rural Water Quality: An Empirical Analysis

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    Concerns about the impact of farm production on the quality of the Nation's drinking and recreational water resources have risen over the past 10 years. Because point sources of pollution were controlled first, agricultural nonpoint sources have become the Nation's largest remaining single water-quality problem. Both public and private costs of policies that address the conflict between agricultural production and water quality are relevant, but measuring the off-farm benefits and costs of changing water quality is difficult. Many of the values placed on these resources are not measured in traditional ways through market prices. This report explores the use of nonmarket valuation methods to estimate the benefits of protecting or improving rural water quality from agricultural sources of pollution. Two case studies show how these valuation methods can be used to include water-quality benefits estimates in economic analyses of specific policies to prevent or reduce water pollution.water quality, nonpoint source pollution, environmental quality, agricultural production, costs, benefits, Resource /Energy Economics and Policy,

    Technical Efficiency in Organic Farming: An Application on Italian Cereal Farms Using a Parametric Approach

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    A stochastic frontier production model was applied to estimate technical efficiency in a sample of Italian organic and conventional cereal farms. The main purpose was to assess which production technique revealed higher efficiency. Statistical tests on the pool sample model suggested that differences between the two cultivation methods were significant from a technological viewpoint. Separate analyses of two sub-samples (93 and 138 observations for organic and conventional farms, respectively) found that conventional farms were significantly more efficient than organic farms, with respect to their specific technology (0.892 vs. 0.825). This implies that organic (conventional) cereal farmers could increase their income to 99.19 /ha (40.95 /ha). Analysis also estimated that land was the technical input with the highest elasticity for both technologies. Furthermore, findings indicated that 63.7% of the differentials between observed and best-practice output was explained by technical inefficiency for the conventional group, while this value was close to unity for organic farms. Some policy implications can be drawn from these findings.organic farming, comparison analysis, cereal-growing, technical efficiency, stochastic frontier production models, Crop Production/Industries, C61, Q18,

    Agile, Web Engineering and Capability Maturity ModelI ntegration : A systematic literature review

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    Context Agile approaches are an alternative for organizations developing software, particularly for those who develop Web applications. Besides, CMMI (Capability Maturity Model Integration) models are well-established approaches focused on assessing the maturity of an organization that develops software. Web Engineering is the field of Software Engineering responsible for analyzing and studying the specific characteristics of the Web. The suitability of an Agile approach to help organizations reach a certain CMMI maturity level in Web environments will be very interesting, as they will be able to keep the ability to quickly react and adapt to changes as long as their development processes get mature. Objective This paper responds to whether it is feasible or not, for an organization developing Web systems, to achieve a certain maturity level of the CMMI-DEV model using Agile methods. Method The proposal is analyzed by means of a systematic literature review of the relevant approaches in the field, defining a characterization schema in order to compare them to introduce the current state-of-the-art. Results The results achieved after the systematic literature review are presented, analyzed and compared against the defined schema, extracting relevant conclusions for the different dimensions of the problem: compatibility, compliance, experience, maturity and Web. Conclusion It is concluded that although the definition of an Agile approach to meet the different CMMI maturity levels goals could be possible for an organization developing Web systems, there is still a lack of detailed studies and analysis on the field

    Measuring Software Process: A Systematic Mapping Study

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    Context: Measurement is essential to reach predictable performance and high capability processes. It provides support for better understanding, evaluation, management, and control of the development process and project, as well as the resulting product. It also enables organizations to improve and predict its process’s performance, which places organizations in better positions to make appropriate decisions. Objective: This study aims to understand the measurement of the software development process, to identify studies, create a classification scheme based on the identified studies, and then to map such studies into the scheme to answer the research questions. Method: Systematic mapping is the selected research methodology for this study. Results: A total of 462 studies are included and classified into four topics with respect to their focus and into three groups based on the publishing date. Five abstractions and 64 attributes were identified, 25 methods/models and 17 contexts were distinguished. Conclusion: capability and performance were the most measured process attributes, while effort and performance were the most measured project attributes. Goal Question Metric and Capability Maturity Model Integration were the main methods and models used in the studies, whereas agile/lean development and small/medium-size enterprise were the most frequently identified research contexts.Ministerio de Economía y Competitividad TIN2013-46928-C3-3-RMinisterio de Economía y Competitividad TIN2016-76956-C3-2- RMinisterio de Economía y Competitividad TIN2015-71938-RED
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