53,363 research outputs found

    Evaluation of Time-Critical Communications for IEC 61850-Substation Network Architecture

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    Present-day developments, in electrical power transmission and distribution, require considerations of the status quo. In other meaning, international regulations enforce increasing of reliability and reducing of environment impact, correspondingly they motivate developing of dependable systems. Power grids especially intelligent (smart grids) ones become industrial solutions that follow standardized development. The International standardization, in the field of power transmission and distribution, improve technology influences. The rise of dedicated standards for SAS (Substation Automation Systems) communications, such as the leading International Electro-technical Commission standard IEC 61850, enforces modern technological trends in this field. Within this standard, a constraint of low ETE (End-to-End) latency should be respected, and time-critical status transmission must be achieved. This experimental study emphasis on IEC 61850 SAS communication standard, e.g. IEC 61850 GOOSE (Generic Object Oriented Substation Events), to implement an investigational method to determine the protection communication delay. This method observes GOOSE behaviour by adopting monitoring and analysis capabilities. It is observed by using network test equipment, i.e. SPAN (Switch Port Analyser) and TAP (Test Access Point) devices, with on-the-shelf available hardware and software solutions

    New firm performance and territorial driving forces

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    The article analyses recent approaches on entry and post-entry performance by new firms, with particular focus on its applicability to small manufacturing firms recently borned in Argentina. The analysis is based on a sample of small firms created in the period 1990-2000 in three intermediate cities in Buenos Aires province (Argentina) in manufacturing sector. The survey collected data about microeconomic and mesoeconomic elements influencing firm performance. Results indicate that tradability is a key factor influencing firm performance. New firms entering markets where the spatial markets are reduced face limited perspectives on expansion. In turn, tradability is also affected by entrepeneurial motivation and, especially in underveloped regions, macroeconomic variables.new firms, post-entry performance, transability

    New firm performance and territorial driving forces.

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    We study post entry performance of manufactuirng firms in 3 municipalities of Buenos Aires province, borned between 1990 and 1999. The aim of the paper is to identify main factors explaining firm growth. The focus is directed to endogenous determinants of firm performance, individual or local as well, taking into account the growing interest those elements are receiving in recent literature about local development. The results show that firm tradability grade is the key variable explaining performance. This factor is strongly influenced by entrepreneur´s profile but also by macroeconomic context.local development, new firms, firm performance, tradability

    Rapid design of tool-wear condition monitoring systems for turning processes using novelty detection

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    Condition monitoring systems of manufacturing processes have been recognised in recent years as one of the key technologies that provide the competitive advantage in many manufacturing environments. It is capable of providing an essential means to reduce cost, increase productivity, improve quality and prevent damage to the machine or workpiece. Turning operations are considered one of the most common manufacturing processes in industry. It is used to manufacture different round objects such as shafts, spindles and pins. Despite recent development and intensive engineering research, the development of tool wear monitoring systems in turning is still ongoing challenge. In this paper, force signals are used for monitoring tool-wear in a feature fusion model. A novel approach for the design of condition monitoring systems for turning operations using novelty detection algorithm is presented. The results found prove that the developed system can be used for rapid design of condition monitoring systems for turning operations to predict tool-wear
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