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

System analysis of fatigue in pilots and co-pilots executing short-hall flight operations

Background: This study was conducted as part of Denel’s South African Regional Aircraft (SARA) development project. Regional aircraft have a maximum flight time of 60 minutes. Hence, the study focuses on matters pertaining to the short-haul flight context. Pilot fatigue has been recognised as a safety concern in the aviation industry. It impacts on pilot performance across the board, not least in the short-haul context. However, the specific factors that lead to pilot fatigue in short-haul operations have not been well researched. Research Aim: To identify and examine the factors which influence pilot/co-pilot fatigue in short-haul aviation contexts. Method: Fatigue is multifaceted, and has multiple definitions and descriptions. It is acknowledged as a complex phenomenon, the development of which is dynamically influenced by various factors. Thus, a systems approach based on the work system model by Smith and Carayon-Sainfort (1989) was adopted for this study. A systems analysis was conducted in two parts: 1) a literature analysis, and 2) expert interviews. Results: Both the literature analysis and the interviews indicated that pilot fatigue in short-haul flight operations represent composite system outcomes influenced by various factors. The factors identified were structured (systematised) into categories, namely organizational factors, task-related factors, environmental factors, factors linked to technology and tools, and non-work-related factors specific to the individual pilot. An example of a task-related factor would be the performance by pilots of multiple take-offs and landings; organizational factors include work time arrangements and duty scheduling (e.g. unpredictable schedule, early starts/late finishes, number of flight sectors in a shift, extended working hours, numerous consecutive work days, standby duties, flight, duty and rest limitations (regulations and guidelines); and short turnaround periods); environmental factors might include the small pressurised cockpit environment, movement restriction, very low humidity, low air pressure, vibrations, high noise levels, low light intensity light, and inclement weather); there are many examples of how tools and technology utilized by pilots might affect their fatigue levels; and finally, pilot-specific non-work-related factors would include things like the pilot’s age, health (lifestyle), family stress, work experience and sleep environment. All of these factors were identified during the literature analysis and have a significant bearing on how fatigue could present in short-haul pilots/co-pilots. Other important fatigue-related factors revealed during the expert interviews included, organizational culture, time management, health implications of fatigue, and management of fatigue. Conclusions: Pilot fatigue is a complex and multi-factorial physiological condition. There are many interacting components which contribute to pilot fatigue in short-haul operations. These should be viewed from an integrated perspective and holistic, systems-based approaches should be taken to manage these issues, particularly in the context of short-haul operations. This would optimize pilot performance and well-being and, most importantly, improve the safety of the work environment to enhance overall operation safety. Limitations: The study does not quantify the contributions made to pilot fatigue by the various factors explored. Therefore, care needs to be taken when designing and implementing interventions based on this research

Dynamic Access Control in Industry 4.0 Systems

Industry 4.0 enacts ad-hoc cooperation between machines, humans, and organizations in supply and production chains. The cooperation goes beyond rigid hierarchical process structures and increases the levels of efficiency, customization, and individualisation of end-products. Efficient processing and cooperation requires exploiting various sensor and process data and sharing them across various entities including computer systems, machines, mobile devices, humans, and organisations. Access control is a common security mechanism to control data sharing between involved parties. However, access control to virtual resources is not sufficient in presence of Industry 4.0 because physical access has a considerable effect on the protection of information and systems. In addition, access control mechanisms have to become capable of handling dynamically changing situations arising from ad-hoc horizontal cooperation or changes in the environment of Industry 4.0 systems. Established access control mechanisms do not consider dynamic changes and the combination with physical access control yet. Approaches trying to address these shortcomings exist but often do not consider how to get information such as the sensitivity of exchanged information. This chapter proposes a novel approach to control physical and virtual access tied to the dynamics of custom product engineering, hence, establishing confidentiality in ad-hoc horizontal processes. The approach combines static design-time analyses to discover data properties with a dynamic runtime access control approach that evaluates policies protecting virtual and physical assets. The runtime part uses data properties derived from the static design-time analysis, as well as the environment or system status to decide about access

A new wireless underground network system for continuous monitoring of soil water contents

A new stand-alone wireless embedded network system has been developed recently for continuous monitoring of soil water contents at multiple depths. This paper presents information on the technical aspects of the system, including the applied sensor technology, the wireless communication protocols, the gateway station for data collection, and data transfer to an end user Web page for disseminating results to targeted audiences. Results from the first test of the network system are presented and discussed, including lessons learned so far and actions to be undertaken in the near future to improve and enhance the operability of this innovative measurement approac

The development of cryogenic storage systems for space flight

Development of cryogenic storage systems for manned space fligh

Lighting Control Systems for Energy Saving and User Acceptance: State-of-the-art and future directions

Lighting accounts for one-fifth of global electricity use. In Sweden, energy demand for lighting corresponds to 20% of the total electricity use in office buildings. Lighting retrofit measures are considered to be among the most cost-efficient way to reduce energy use in buildings. In particular, the use of advanced lighting control systems promises energy savings of between 2 and 60%, but system failures and poor user acceptance have been significant limitations so far. This thesis uses literature reviews and field studies to investigate the effect of lighting control systems on energy use and user acceptance. In the first part of the thesis, an extensive literature review on lighting control systems indicates that manually controlled systems are generally more accepted by the users. Systems with high automation and no manual override tend to be deactivated or even sabotaged. Consequently, user behavior plays a fundamental role in ensuring proper function and actual energy savings of the lighting control system. The review also showed that presence and absence detection are often combined under the overarching category ‘occupancy strategies’, although they yield very different energy savings. The review of daylight harvesting systems highlighted critical issues relating to design and commissioning. Two field studies in individual offices were conducted. Absence and presence detection, daylight harvesting and a simple task light were tested in a real-life work environment, where energy use and user acceptance were monitored. The studies showed that the definition ‘occupancy strategies’ is not completely appropriate, since ‘absence’ and ‘presence’ detection yield different energy savings and user acceptance. The second field study showed that daylight harvesting systems could perform well, on condition that careful design and commissioning are performed along with provision of a manual override. However, the field study showed that the use of sensors and microcontrollers raised the energy demand for parasitic power (standby), which might be significant in relation to final energy use, especially with low occupancy rates and high-efficiency light sources. Lighting control systems based on wireless networks and integrated in the building management system are expected to increase during the coming years. This will overcome many of the current issues with advanced lighting control systems, but it will also require additional skills on the part of the designer and installer. In the meantime, occupancy strategies represent a good alternative in energy-efficient lighting retrofit

Deep Underground Science and Engineering Laboratory - Preliminary Design Report

The DUSEL Project has produced the Preliminary Design of the Deep Underground Science and Engineering Laboratory (DUSEL) at the rehabilitated former Homestake mine in South Dakota. The Facility design calls for, on the surface, two new buildings - one a visitor and education center, the other an experiment assembly hall - and multiple repurposed existing buildings. To support underground research activities, the design includes two laboratory modules and additional spaces at a level 4,850 feet underground for physics, biology, engineering, and Earth science experiments. On the same level, the design includes a Department of Energy-shepherded Large Cavity supporting the Long Baseline Neutrino Experiment. At the 7,400-feet level, the design incorporates one laboratory module and additional spaces for physics and Earth science efforts. With input from some 25 science and engineering collaborations, the Project has designed critical experimental space and infrastructure needs, including space for a suite of multidisciplinary experiments in a laboratory whose projected life span is at least 30 years. From these experiments, a critical suite of experiments is outlined, whose construction will be funded along with the facility. The Facility design permits expansion and evolution, as may be driven by future science requirements, and enables participation by other agencies. The design leverages South Dakota's substantial investment in facility infrastructure, risk retirement, and operation of its Sanford Laboratory at Homestake. The Project is planning education and outreach programs, and has initiated efforts to establish regional partnerships with underserved populations - regional American Indian and rural populations

SECURE AND RELIABLE POWER SUPPLY WITH CHALLENGES- SMART GRID

Smart Grid implementations will certainly increase the quantity, quality and use of information available from advanced sensing, computing and communications hardware as well as software. There is virtually universal agreement that it is necessary to upgrade the electric grid to increase overall system efficiency and reliability. Many technologies currently in use by the grid is outdated and in many cases unreliable. The reliance on old technology leads to inefficient systems, costing unnecessary money to the utilities, consumers and taxpayers. To upgrade the grid and to operate an improved grid will require significant dependence on distributed intelligence and broadband communication capabilities. The access and communications capabilities require the latest in security technology which are reliable for extremely large, wide-area communications networks. This paper discusses features, reasons of development, barriers and their solutions for a smart grid system