Advanced telemetry systems for payloads. Technology needs, objectives and issues

The current trends in advanced payload telemetry are the new developments in advanced modulation/coding, the applications of intelligent techniques, data distribution processing, and advanced signal processing methodologies. Concerted efforts will be required to design ultra-reliable man-rated software to cope with these applications. The intelligence embedded and distributed throughout various segments of the telemetry system will need to be overridden by an operator in case of life-threatening situations, making it a real-time integration issue. Suitable MIL standards on physical interfaces and protocols will be adopted to suit the payload telemetry system. New technologies and techniques will be developed for fast retrieval of mass data. Currently, these technology issues are being addressed to provide more efficient, reliable, and reconfigurable systems. There is a need, however, to change the operation culture. The current role of NASA as a leader in developing all the new innovative hardware should be altered to save both time and money. We should use all the available hardware/software developed by the industry and use the existing standards rather than inventing our own

Towards Standardisation Measures to Support the Security of Control and Real-Time Systems for Energy Critical Infrastructures

This report outlines the context for control and real time systems vulnerability in the energy sector, their role in energy critical infrastructures and their emerging vulnerabilities as they were put in light by some recent episodes. Then it provides a survey on the current efforts to set up reference frameworks addressing the broad issue of supervisory and control systems security. It discusses the role of standards and outlines the reference approaches in that respect. The current attitude of Europe towards the issue of control systems security is discussed and compared with the US situation, based on a stakeholder consultation, and gaps and challenges are outlined. A set of recommendations for policy measures to address the issue is given.JRC.DG.G.6-Security technology assessmen

Future Directions of Internet-based Control Systems

Recent advances in object-oriented, client/server technologies, and the Internet are supplying the technology enablers needed to provide a uniform information architecture that can be used to build software architecture allowing the inter-operation and integration of a wide set of diverse applications. Moreover the emerging standards start playing a significant role in the shaping of automation architectures in enterprises. The inclusion within a classical control system of Internet-related technologies and open distributed application concepts would give the present system compliance with current and future technological trends. At the present time, in the field of the industrial automation, real-time embedded control systems more and more need Internet connectivity for operations of remote plant administration, training, and supervisory activities. In this paper the state of the art in embedded control systems is presented within the field of industrial automation applications, and the technological scenario is discussed, followed by the trend for the evolution in process control systems. Guidelines for the design of innovative, thus competitive control systems are suggested. A case study is presented, outcome of an EC project in which one of the authors is involved, where a remote maintenance system is realized

Basis Token Consistency: A Practical Mechanism for Strong Web Cache Consistency

With web caching and cache-related services like CDNs and edge services playing an increasingly significant role in the modern internet, the problem of the weak consistency and coherence provisions in current web protocols is becoming increasingly significant and drawing the attention of the standards community [LCD01]. Toward this end, we present definitions of consistency and coherence for web-like environments, that is, distributed client-server information systems where the semantics of interactions with resource are more general than the read/write operations found in memory hierarchies and distributed file systems. We then present a brief review of proposed mechanisms which strengthen the consistency of caches in the web, focusing upon their conceptual contributions and their weaknesses in real-world practice. These insights motivate a new mechanism, which we call "Basis Token Consistency" or BTC; when implemented at the server, this mechanism allows any client (independent of the presence and conformity of any intermediaries) to maintain a self-consistent view of the server's state. This is accomplished by annotating responses with additional per-resource application information which allows client caches to recognize the obsolescence of currently cached entities and identify responses from other caches which are already stale in light of what has already been seen. The mechanism requires no deviation from the existing client-server communication model, and does not require servers to maintain any additional per-client state. We discuss how our mechanism could be integrated into a fragment-assembling Content Management System (CMS), and present a simulation-driven performance comparison between the BTC algorithm and the use of the Time-To-Live (TTL) heuristic.National Science Foundation (ANI-9986397, ANI-0095988

Automated Subsystem Control for Life Support System (ASCLSS)

The Automated Subsystem Control for Life Support Systems (ASCLSS) program has successfully developed and demonstrated a generic approach to the automation and control of space station subsystems. The automation system features a hierarchical and distributed real-time control architecture which places maximum controls authority at the lowest or process control level which enhances system autonomy. The ASCLSS demonstration system pioneered many automation and control concepts currently being considered in the space station data management system (DMS). Heavy emphasis is placed on controls hardware and software commonality implemented in accepted standards. The approach demonstrates successfully the application of real-time process and accountability with the subsystem or process developer. The ASCLSS system completely automates a space station subsystem (air revitalization group of the ASCLSS) which moves the crew/operator into a role of supervisory control authority. The ASCLSS program developed over 50 lessons learned which will aide future space station developers in the area of automation and controls.

Essays on remote monitoring as an emerging tool for centralized management of decentralized wastewater systems

According to the United States Environmental Protections Agency (USEPA), nearly one in four households in the United States depends on an individual septic system (commonly referred as an onsite system or a decentralized wastewater system) to treat and disperse wastewater. More than half of these systems are over 30 years old, and surveys indicate at least 10 to 20% might not be functioning properly. The USEPA concluded in its 1997 report to Congress that adequately managed decentralized wastewater systems (DWS) are a cost-effective and long-term option for meeting public health and water quality goals, particularly in less densely populated areas.;The major challenge however is the absence of a guiding national regulatory framework based on consistent performance-based standards and lack of proper management of DWS. These inconsistencies pose a significant threat to our water resources, local economies, and public health. This dissertation addresses key policy and regulatory strategies needed in response to the new realities confronting decentralized wastewater management. The two core objectives of this research are to demonstrate the centralized management of DWS paradigm and to present a scientific methodology to develop performance-based standards (a regulatory shift from prescriptive methods) using remote monitoring.;The underlying remote monitoring architecture for centralized DWS management and the value of science-based policy making are presented. Traditionally, prescriptive standards using conventional grab sampling data are the norm by which most standards are set. Three case studies that support the potential of remote monitoring as a tool for standards development and system management are presented. The results revealed a vital role for remote monitoring in the development of standardized protocols, policies and procedures that are greatly lacking in this field.;This centralized management and remote monitoring paradigm fits well and complements current USEPA policy (13 elements of management); meets the growing need for qualitative data (objective and numerical); has better time efficiencies as real-time events are sampled and translated into machine-readable signals in a short period of time; allows cost saving rapid response to system recovery and operation; produces labor and economic efficiencies through targeted responses; and, improves the quality and operational costs of any management program.;This project was funded by the USEPA grant # C-82878001 as part of the National Onsite Demonstration Project (NODP), West Virginia University

Reduction of carbon emissions in a mediterranean urban wastewater treatment plant

In the last few decades, with the rapid growth of population, and more than half of them living in cities, the urban wastewater treatment has become a big challenge that consumes many resources, namely energy. In a climate change scenario, the Mediterranean region is facing more frequent water scarcity periods, and urban water reuse can be a solution, at least for supplying some non-potable water uses. In this context, the performance of urban wastewater treatment plants (WWTP) is of utter importance, to produce environmentally safe treated water while reducing energy consumption and carbon emissions (CE). Activated sludge is the biological process most widely used in wastewater treatment and requires aeration systems in order to promote the oxidation of organic matter and ammonia. It is known that the energy consumed in the aeration processes is of major importance for the global WWTP CE. This study was carried out in a WWTP in southern Portugal, wherein an aeration control system that responds in real time to ammonia and nitrate concentrations was tested. The system is set to optimize the duration of the aerated and non-aerated periods, for nitrification and denitrification. During the experimental period, BOD, COD, Escherichia coli, TN and TP were monitored in the treated effluent, in order to verify the quality standards that allow its reuse. The aeration control system contributed to a decrease of about 13% of the specific energy consumption, when compared with the corresponding period in previous years, representing a CE reduction of about 1.2 t CO2 eq, during the experimental period. The treated effluent maintained its high quality standards and can be used, for example, in agricultural irrigation of local crops. Aeration control systems reacting in real time can have an important role to decrease CE of urban WWTPs; however, further research is needed, including more WWTPs and analyzing seasonal variations in energy consumption over the year.info:eu-repo/semantics/publishedVersio

Bicycle Sharing Systems: Fast and Slow Urban Mobility Dynamics

In cities all around the world, new forms of urban micromobility have observed rapid and wide-scale adoption due to their benefits as a shared mode that are environmentally friendly, convenient and accessible. Bicycle sharing systems are the most established among these modes, facilitating complete end-to-end journeys as well as forming a solution for the first/last mile issue that public transportation users face in getting to and from transit stations. They mark the beginnings of a gradual transition towards a more sustainable transportation model that include greater use of shared and active modes. As such, understanding the way in which these systems are used is essential in order to improve their management and efficiency. Given the lack of operator published data, this thesis aims to explore the utility of open bicycle sharing system data standards that are intended for real-time dissemination of bicycle locations in uncovering novel insights into their activity dynamics over varying temporal and geographical scales. The thesis starts by exploring bicycle sharing systems at a global-scale, uncovering their long-term growth and evolution through the development of data cleaning and metric creation heuristics that also form the foundations of the most comprehensive classification of systems. Having established the values of these metrics in conducting comparisons at scale, the thesis then analyses the medium-term impacts of mobility interventions in the context of the COVID-19 pandemic, employing spatio-temporal and network analysis methods that highlight their adaptability and resilience. Finally, the thesis closes with the analysis of granular spatial and temporal dynamics within a dockless system in London that enable the identification of the variations in journey locations throughout different times of the day. In each of these cases, the research highlights the indispensable value of open data and the important role that bicycle sharing systems play in urban mobility