Pipeline AER arbitration with event aging

We present a simple circuit to handle communication between cells of neuromorphic arrays. It allows cells to operate continuously without waiting for acknowledgement signals back from the AER (Address Event Representation) arbitration circuitry. The module also implements aging of cell petitions i.e., old petitions to access to the AER bus are automatically discarded to give priority to the more recent ones and alleviate the bus congestion. The new arbitration scheme has been implemented and tested. A particular application scenario with an image sensor with spiking pixels that sense light continuously is explained. The sensing errors per event due to discontinued pixel operation can be minimized a factor 8.1. Experimental data obtained with real visual scenes are provided.Universidad de Cádiz PR2016-072Ministerio de Economía y Competitividad TEC2015-66878- C3-1-RJunta de Andalucía TIC 2012-2338Office of Naval Research (USA) N00014141035

An Ultra-Low Cost and Multicast-Enabled Asynchronous NoC for Neuromorphic Edge Computing

Biological brains are increasingly taken as a guide toward more efficient forms of computing. The latest frontier considers the use of spiking neural-network-based neuromorphic processors for near-sensor data processing, in order to fit the tight power and resource budgets of edge computing devices. However, a prevailing focus on brain-inspired computing and storage primitives in the design of neuromorphic systems is currently bringing a fundamental bottleneck to the forefront: chip-scale communications. While communication architectures (typically, a network-on-chip) are generally inspired by, or even borrowed from, general purpose computing, neuromorphic communications exhibit unique characteristics: they consist of the event-driven routing of small amounts of information to a large number of destinations within tight area and power budgets. This article aims at an inflection point in network-on-chip design for brain-inspired communications, revolving around the combination of cost-effective and robust asynchronous design, architecture specialization for short messaging and lightweight hardware support for tree-based multicast. When validated with functional spiking neural network traffic, the proposed NoC delivers energy savings ranging from 42% to 71% over a state-of-the-art NoC used in a real multi-core neuromorphic processor for edge computing applications.<br/

Zuverlässige und Energieeffiziente gemischt-kritische Echtzeit On-Chip Systeme

Multi- and many-core embedded systems are increasingly becoming the target for many applications that require high performance under varying conditions. A resulting challenge is the control, and reliable operation of such complex multiprocessing architectures under changes, e.g., high temperature and degradation. In mixed-criticality systems where many applications with varying criticalities are consolidated on the same execution platform, fundamental isolation requirements to guarantee non-interference of critical functions are crucially important. While Networks-on-Chip (NoCs) are the prevalent solution to provide scalable and efficient interconnects for the multiprocessing architectures, their associated energy consumption has immensely increased. Specifically, hard real-time NoCs must manifest limited energy consumption as thermal runaway in such a core shared resource jeopardizes the whole system guarantees. Thus, dynamic energy management of NoCs, as opposed to the related work static solutions, is highly necessary to save energy and decrease temperature, while preserving essential temporal requirements. In this thesis, we introduce a centralized management to provide energy-aware NoCs for hard real-time systems. The design relies on an energy control network, developed on top of an existing switch arbitration network to allow isolation between energy optimization and data transmission. The energy control layer includes local units called Power-Aware NoC controllers that dynamically optimize NoC energy depending on the global state and applications’ temporal requirements. Furthermore, to adapt to abnormal situations that might occur in the system due to degradation, we extend the concept of NoC energy control to include the entire system scope. That is, online resource management employing hierarchical control layers to treat system degradation (imminent core failures) is supported. The mechanism applies system reconfiguration that involves workload migration. For mixed-criticality systems, it allows flexible boundaries between safety-critical and non-critical subsystems to safely apply the reconfiguration, preserving fundamental safety requirements and temporal predictability. Simulation and formal analysis-based experiments on various realistic usecases and benchmarks are conducted showing significant improvements in NoC energy-savings and in treatment of system degradation for mixed-criticality systems improving dependability over the status quo.Eingebettete Many- und Multi-core-Systeme werden zunehmend das Ziel für Anwendungen, die hohe Anfordungen unter unterschiedlichen Bedinungen haben. Für solche hochkomplexed Multi-Prozessor-Systeme ist es eine grosse Herausforderung zuverlässigen Betrieb sicherzustellen, insbesondere wenn sich die Umgebungseinflüsse verändern. In Systeme mit gemischter Kritikalität, in denen viele Anwendungen mit unterschiedlicher Kritikalität auf derselben Ausführungsplattform bedient werden müssen, sind grundlegende Isolationsanforderungen zur Gewährleistung der Nichteinmischung kritischer Funktionen von entscheidender Bedeutung. Während On-Chip Netzwerke (NoCs) häufig als skalierbare Verbindung für die Multiprozessor-Architekturen eingesetzt werden, ist der damit verbundene Energieverbrauch immens gestiegen. Daher sind dynamische Plattformverwaltungen, im Gegensatz zu den statischen, zwingend notwendig, um ein System an die oben genannten Veränderungen anzupassen und gleichzeitig Timing zu gewährleisten. In dieser Arbeit entwickeln wir energieeffiziente NoCs für harte Echtzeitsysteme. Das Design basiert auf einem Energiekontrollnetzwerk, das auf einem bestehenden Switch-Arbitration-Netzwerk entwickelt wurde, um eine Isolierung zwischen Energieoptimierung und Datenübertragung zu ermöglichen. Die Energiesteuerungsschicht umfasst lokale Einheiten, die als Power-Aware NoC-Controllers bezeichnet werden und die die NoC-Energie in Abhängigkeit vom globalen Zustand und den zeitlichen Anforderungen der Anwendungen optimieren. Darüber hinaus wird das Konzept der NoC-Energiekontrolle zur Anpassung an Anomalien, die aufgrund von Abnutzung auftreten können, auf den gesamten Systemumfang ausgedehnt. Online- Ressourcenverwaltungen, die hierarchische Kontrollschichten zur Behandlung Abnutzung (drohender Kernausfälle) einsetzen, werden bereitgestellt. Bei Systemen mit gemischter Kritikalität erlaubt es flexible Grenzen zwischen sicherheitskritischen und unkritischen Subsystemen, um die Rekonfiguration sicher anzuwenden, wobei grundlegende Sicherheitsanforderungen erhalten bleiben und Timing Vorhersehbarkeit. Experimente werden auf der Basis von Simulationen und formalen Analysen zu verschiedenen realistischen Anwendungsfallen und Benchmarks durchgeführt, die signifikanten Verbesserungen bei On-Chip Netzwerke-Energieeinsparungen und bei der Behandlung von Abnutzung für Systeme mit gemischter Kritikalität zur Verbesserung die Systemstabilität gegenüber dem bisherigen Status quo zeigen

Towards a Policy Framework for Iraq’s Petroleum Industry and an Integrated Federal Energy Strategy

The “Policy Framework for Iraq’s Petroleum Industry” is a logical structure that establishes the rules to guide decisions and manage processes to achieve economically efficient outcomes within the energy sector. It divides policy applications between regulatory and regulated practices, and defines the governance of the public sector across the petroleum industry and relevant energy portfolios. In many “Rentier States” where countries depend on a single source of income such as oil revenues, overlapping powers of authority within the public sector between policy makers and operators has led to significant conflicts of interest that have resulted in the mismanagement of resources and revenues, corruption, failed strategies and the ultimate failure of the system. Some countries have succeeded in identifying areas for progressive reform, whilst others failed due to various reasons discussed in this thesis. Iraq fits into the category of a country that has failed to implement reform and has become a classic case of a rentier state. The primary aim of this research is to produce a policy framework applicable to the local settings of Iraq’s petroleum industry, together with an implementation strategy that helps the country in its transition from legacy practices to sustainable policies compatible with the federal constitution of 2005. Such a framework would observe the legislative applications that appeared in the aftermath of establishing a federal regime. The framework will help to rationalise the decisions and processes that sustain the governance and business practices across the energy value chain of Iraq. The development of a policy framework exemplified by the final setting of the Federal Energy Council (FEC) proposed in this thesis has to take into account the existing legal framework, the legacy of previous policies and the governance arrangements of developing policy under a new federal regime. A review of federal models of major resource holders that may share similar attributes to Iraq is subsequently necessary to identify the appropriate fiscal regime which fits Iraq’s legal system. Conflicts of interest and how they have been reduced or eliminated in case study countries, must be identified to instruct the final proposed framework. This research also examines key factors that influence the petroleum sector of a federalized major resource holder. Furthermore, qualitative in-depth case studies have been conducted to investigate the research problem. This research is complemented by numerous interviews that took place with high profile executives, policy makers and senior officials, as well as a review of data relevant to Iraq from an array of historical literature. The findings of this thesis will comprise a proposed “policy framework for Iraq’s petroleum industry,” exemplified by the FEC that the federal government of Iraq needs to adopt to transition energy institutions from the legacy of centralised rule to a modern and efficient petroleum industry in a democratic setting

SpiNNaker - A Spiking Neural Network Architecture

20 years in conception and 15 in construction, the SpiNNaker project has delivered the world’s largest neuromorphic computing platform incorporating over a million ARM mobile phone processors and capable of modelling spiking neural networks of the scale of a mouse brain in biological real time. This machine, hosted at the University of Manchester in the UK, is freely available under the auspices of the EU Flagship Human Brain Project. This book tells the story of the origins of the machine, its development and its deployment, and the immense software development effort that has gone into making it openly available and accessible to researchers and students the world over. It also presents exemplar applications from ‘Talk’, a SpiNNaker-controlled robotic exhibit at the Manchester Art Gallery as part of ‘The Imitation Game’, a set of works commissioned in 2016 in honour of Alan Turing, through to a way to solve hard computing problems using stochastic neural networks. The book concludes with a look to the future, and the SpiNNaker-2 machine which is yet to come

Diseño de un sensor solar basado en eventos

Explicar en qué consiste un sensor solar y dar una visión general sobre el estado de arte y el cambio de paradigma que suponen los sensores solares basados en eventos.Universidad de sevilla.Máster Universitario en Microelectrónica: Diseño y Aplicaciones de Sistemas Micro/Nanométrico

An investigation into the effectiveness of the design and enforcement of Nigeria's anti-gas flaring law and policy regimes, and the considerations of measures that could improve environmental regulatory compliance.

Since the discovery of the commercial hydrocarbon deposit in 1956, activity of Nigeria's petroleum industry has dramatically increased. The industry now contributes an average of two million barrels of crude oil daily to the global oil market. However, while bringing this development, the industry has become a source of misery for the oil-producing host communities, whose survival is endangered by the scourge of pollution from associated gas flaring. Associated gas (AG) flaring is widely acknowledged as a significant contributor to greenhouse gas emissions, negatively impacting the environment and economy. Given its adverse effects, governments of oil-producing nations and industries have a responsibility to end flaring. Nevertheless, only a few such nations have significantly reduced flaring, while in most other jurisdictions like Nigeria, flaring continues to rise with increased oil production. In this regard, this study critically investigates the appropriateness and effectiveness of the design and enforcement of anti-gas flaring laws and the policy regimes currently operating in Nigeria. The study provided a general overview of the research context, and emphasised the role of effective law and policy regimes in reducing flaring in Nigeria. It critically analysed and addressed the following key issues, among others: the role of appropriately designed anti-gas flaring law and policy regimes; the effectiveness of regulatory enforcement; and the institutional characteristics of an effective flaring regulatory agency. It also addressed other relevant factors that affect flaring volumes, like penalties, incentives and the effects of contractual rights in addressing AG flaring issues. The study argues that Nigeria currently has appropriately designed law and policy regimes, but the enforcement is ineffective. The study finds several reasons that have led to the ineffectiveness and recommends measures that would help the country end gas flaring. The study suggests that oil-producing nations should design and establish clear and precise policies and legislation with independent regulatory agencies to avoid interference and conflict of interest. It also recommends adequate penalties and incentives to encourage effective enforcement of the AG flaring regulations

A Bulk Driven Transimpedance CMOS Amplifier for SiPM Based Detection

The contribution of this work lies in the development of a bulk driven operationaltransconducctance amplifier which can be integrated with other analog circuits andphotodetectors in the same chip for compactness, miniaturization and reducing thepower. Silicon photomultipliers, also known as SiPMs, when coupled with scintillator materials are used in many imaging applications including nuclear detection. This thesis discuss the design of a bulk-driven transimpedance amplifier suitable for detectors where the front end is a SiPM. The amplifier was design and fabricated in a standard standard CMOS process and is suitable for integration with CMOS based SiPMs and commercially available SiPMs. Specifically, the amplifier was verified in simulations and experiment using circuit models for the SiPM. The bulk-driven amplifier’s performance, was compared to a commerciallyavailable amplifier with approximately the same open loop gain (70dB). Bothamplifiers were verified with two different light sources, a scintillator and a SiPM.The energy resolution using the bulk driven amplifier was 8.6% and was 14.2% forthe commercial amplifier indicating the suitability of the amplifier design for portable systems