Energy efficiency in discrete-manufacturing systems: insights, trends, and control strategies

Since the depletion of fossil energy sources, rising energy prices, and governmental regulation restrictions, the current manufacturing industry is shifting towards more efficient and sustainable systems. This transformation has promoted the identification of energy saving opportunities and the development of new technologies and strategies oriented to improve the energy efficiency of such systems. This paper outlines and discusses most of the research reported during the last decade regarding energy efficiency in manufacturing systems, the current technologies and strategies to improve that efficiency, identifying and remarking those related to the design of management/control strategies. Based on this fact, this paper aims to provide a review of strategies for reducing energy consumption and optimizing the use of resources within a plant into the context of discrete manufacturing. The review performed concerning the current context of manufacturing systems, control systems implemented, and their transformation towards Industry 4.0 might be useful in both the academic and industrial dimension to identify trends and critical points and suggest further research lines.Peer ReviewedPreprin

Tradeoffs in jet inlet design: a historical perspective

The design of the inlet(s) is one of the most demanding tasks of the development process of any gas turbine-powered aircraft. This is mainly due to the multi-objective and multidisciplinary nature of the exercise. The solution is generally a compromise between a number of conflicting goals and these conflicts are the subject of the present paper. We look into how these design tradeoffs have been reflected in the actual inlet designs over the years and how the emphasis has shifted from one driver to another. We also review some of the relevant developments of the jet age in aerodynamics and design and manufacturing technology and we examine how they have influenced and informed inlet design decision

From Supply Chains to Total Product Systems

The evolution of supply chain management and practice has had an integral and expanding role in contemporary global economic and socio-political change over the past 25 years or so. Thi srole is moving closer to centre stage with the emergence of business models equating to 'total product systems'. The impacts of advanced supply chain practice include driving fundamental changes in approach to product design, the concept of 'product', production methods, distribution, marketing, aftermarket support and end-of-life (EOL) reprocessing. Viewed in their full context, methods in supply chain management (SCM) have major influences on societal functioning and on economic development at global, national and local levels. Even the supply chains for simple products can involve several different industries and link many companies, large and small. Those for complex products may span several technological domains and economic sectors, linking hundreds or sometimes thousands of companies

High-Growth Entrepreneurial Firms in Africa: A Quantile Regression Approach

This paper studies the growth performance of a large set of entrepreneurial firms in ten manufacturing sectors of eleven Sub-Saharan African countries. The focus of the paper is on identifying those entrepreneurs. attributes and firm characteristics that tend to generate a significant number of high-growth firms in these countries. To this end, we use a quantile regression, which provides a more complete estimation of the growth distribution of firms conditional on different attributes. The results indicate that especially firms that engage in product innovation, have their own transport means and are connected to the internet through their own website are characterized by higher growth rates and display a more skewed distribution to the right, hosting a higher number of high-growth firms. The effect of the last two variables, which relate to distance-bridging modes of infrastructure, points to the self-reinforcing growth effects.quantile regression, high-growth firms, firm growth, Africa

Energy challenges for ICT

The energy consumption from the expanding use of information and communications technology (ICT) is unsustainable with present drivers, and it will impact heavily on the future climate change. However, ICT devices have the potential to contribute signi - cantly to the reduction of CO2 emission and enhance resource e ciency in other sectors, e.g., transportation (through intelligent transportation and advanced driver assistance systems and self-driving vehicles), heating (through smart building control), and manu- facturing (through digital automation based on smart autonomous sensors). To address the energy sustainability of ICT and capture the full potential of ICT in resource e - ciency, a multidisciplinary ICT-energy community needs to be brought together cover- ing devices, microarchitectures, ultra large-scale integration (ULSI), high-performance computing (HPC), energy harvesting, energy storage, system design, embedded sys- tems, e cient electronics, static analysis, and computation. In this chapter, we introduce challenges and opportunities in this emerging eld and a common framework to strive towards energy-sustainable ICT

A Survey on Bottelneck Analysis for Industrial Production

Manufacturing systems have evolved rapidly since their inception and this transformation is expected to continue in a pursuit of optimum utility. A fixed sequence of machine tools connected by an automated material handling system for mass production of a small family of complex parts (several million parts per year). Bottelnecks have several benefits. They require less manpower and space. They ensure low work in progress and lower lead time. Bottelnecks are employed for mass production of a fixed product or a very narrow range of product variants. This paper discuss about different bottleneck balancing problem, process planning and line configuration. For optimize bottleneck is must to be design features of the product are grouped and machining operations are sequenced in an optimal manner. The objective is to find out problem and possible solution on the handling time fraction of the cycle time consisting mainly of orientation change time and tool change time in different bottleneck sequencing, which is used by industrial production

A design of DSS for mass production machining systems

http://bulletin.pan.pl/(57-3)265.pdfInternational audienceIn this paper, we present a decision support tool (DSS) for preliminary design of transfer machines with rotary or mobile tables. In these transfer machines, the machining operations are executed on working positions equipped by standard multi-spindle heads. A part is sequentially machined on m working positions and is moved from one position to the next using a rotary or a mobile table. The operations are grouped into blocks, where the operations of the same block are simultaneously performed by one multi-spindle head. At the preliminary design stage, the goal is to select the number of working positions and to decide which spindle heads will be installed minimizing the machine cost while respecting a given production rate. The paper presents the overall approach and depicts mathematical and decision-support methods developed and implemented in a software for the optimization of preliminary design (or reconfiguration) of such machining systems