Far-infrared polarimetry from the Stratospheric Observatory for Infrared Astronomy

Multi-wavelength imaging polarimetry at far-infrared wavelengths has proven to be an excellent tool for studying the physical properties of dust, molecular clouds, and magnetic fields in the interstellar medium. Although these wavelengths are only observable from airborne or space-based platforms, no first-generation instrument for the Stratospheric Observatory for Infrared Astronomy (SOFIA) is presently designed with polarimetric capabilities. We study several options for upgrading the High-resolution Airborne Wideband Camera (HAWC) to a sensitive FIR polarimeter. HAWC is a 12 x 32 pixel bolometer camera designed to cover the 53 - 215 micron spectral range in 4 colors, all at diffraction-limited resolution (5 - 21 arcsec). Upgrade options include: (1) an external set of optics which modulates the polarization state of the incoming radiation before entering the cryostat window; (2) internal polarizing optics; and (3) a replacement of the current detector array with two state-of-the-art superconducting bolometer arrays, an upgrade of the HAWC camera as well as polarimeter. We discuss a range of science studies which will be possible with these upgrades including magnetic fields in star-forming regions and galaxies and the wavelength-dependence of polarization.Comment: 12 pages, 5 figure

Embedded Machine Learning: Emphasis on Hardware Accelerators and Approximate Computing for Tactile Data Processing

Machine Learning (ML) a subset of Artificial Intelligence (AI) is driving the industrial and technological revolution of the present and future. We envision a world with smart devices that are able to mimic human behavior (sense, process, and act) and perform tasks that at one time we thought could only be carried out by humans. The vision is to achieve such a level of intelligence with affordable, power-efficient, and fast hardware platforms. However, embedding machine learning algorithms in many application domains such as the internet of things (IoT), prostheses, robotics, and wearable devices is an ongoing challenge. A challenge that is controlled by the computational complexity of ML algorithms, the performance/availability of hardware platforms, and the application\u2019s budget (power constraint, real-time operation, etc.). In this dissertation, we focus on the design and implementation of efficient ML algorithms to handle the aforementioned challenges. First, we apply Approximate Computing Techniques (ACTs) to reduce the computational complexity of ML algorithms. Then, we design custom Hardware Accelerators to improve the performance of the implementation within a specified budget. Finally, a tactile data processing application is adopted for the validation of the proposed exact and approximate embedded machine learning accelerators. The dissertation starts with the introduction of the various ML algorithms used for tactile data processing. These algorithms are assessed in terms of their computational complexity and the available hardware platforms which could be used for implementation. Afterward, a survey on the existing approximate computing techniques and hardware accelerators design methodologies is presented. Based on the findings of the survey, an approach for applying algorithmic-level ACTs on machine learning algorithms is provided. Then three novel hardware accelerators are proposed: (1) k-Nearest Neighbor (kNN) based on a selection-based sorter, (2) Tensorial Support Vector Machine (TSVM) based on Shallow Neural Networks, and (3) Hybrid Precision Binary Convolution Neural Network (BCNN). The three accelerators offer a real-time classification with monumental reductions in the hardware resources and power consumption compared to existing implementations targeting the same tactile data processing application on FPGA. Moreover, the approximate accelerators maintain a high classification accuracy with a loss of at most 5%

Data warehouse design for mobile environment

Analysis and design are very important roles in Data Warehouse (DW) system development and forms as a backbone of any successful or failure of the DWproject. The emergence trends of ubiquitous-based application required DW system to be implemented in the mobile environment.However, current analysis and design approaches are based on existing DW environments that focusing on the deployment of DW system in static client-based applications. This will create the limitations on user accessed and reduced the used of analytical information by the decision makers.Consequently, this will prolong the adoption of business intelligence (BI) applications to the users and organisations. This research is to suggest an approach for designing the DW and implement the DW system on the mobile environments.A variant dimension modeling technique will be used to enhance the DW modeling in order to accommodate the requirements of mobile characteristics in the DW design

On the conception and mechanical design of customized glasses for augmented reality

Wearable devices such as smart glasses are one of the main challenges of augmented reality (AR) adoption in the consumer market. Despite the significant advances in recent years, the hardware available presents a bulky form factor and does not bring significant value to everyday life. LusoVU is focused on developing new AR smart glasses accessible to the general population with their HIDO technology. This dissertation combines the areas of product devel-opment and augmented reality for the development of a new prototype for LusoVU. The aim is to integrate the electrical and optical elements of the HIDO technology into a frame design that aligns with society’s standards of an acceptable everyday eyewear device, whilst consider-ing all the constraints and tradeoffs of the optical technology. The research hereafter presented followed the steps of a product development, namely: internal and external benchmarking, identification of client needs; product specifications; concept generation and selection; mod-elling and prototyping. It presents and describes the many iterations to achieve the final de-sign. The final design meets the product specifications and customer needs and will now be submitted in the coming months to the biometric analysis.Aparelhos portáteis para uso quotidiano, tais como óculos inteligentes, são um dos principais desafios da adoção da realidade aumentada no mercado do consumidor. Apesar dos grandes avanços nos últimos anos, o equipamento disponível apresenta um formato volumoso e ainda não acrescenta valor significativo ao dia a dia. A LusoVU está focada no desenvolvimento de novos óculos inteligentes, acessíveis à população em geral, com a sua tecnologia HIDO. Esta tese combina as áreas de desenvolvimento de produto e de realidade aumentada para o desenvolvimento de um novo protótipo para LusoVU. O objetivo é a conceção e o projeto de armações de óculos, alinhado com os padrões estéticos da sociedade, integrando os elementos óticos e eletrónicos da tecnologia HIDO e considerando todas as suas restrições. O presente trabalho segue as etapas do desenvolvimento do produto: benchmarking interno e externo, identificação das necessidades do cliente; especificações do produto; geração e seleção de conceitos; modelação e prototipagem. A dissertação apresenta e descreve as várias iterações necessárias para alcançar o projeto final. O projeto final atende às especificações do produto e às necessidades do cliente, e será agora submetido nos próximos meses à análise biométrica

The AXIOM software layers

AXIOM project aims at developing a heterogeneous computing board (SMP-FPGA).The Software Layers developed at the AXIOM project are explained.OmpSs provides an easy way to execute heterogeneous codes in multiple cores. People and objects will soon share the same digital network for information exchange in a world named as the age of the cyber-physical systems. The general expectation is that people and systems will interact in real-time. This poses pressure onto systems design to support increasing demands on computational power, while keeping a low power envelop. Additionally, modular scaling and easy programmability are also important to ensure these systems to become widespread. The whole set of expectations impose scientific and technological challenges that need to be properly addressed.The AXIOM project (Agile, eXtensible, fast I/O Module) will research new hardware/software architectures for cyber-physical systems to meet such expectations. The technical approach aims at solving fundamental problems to enable easy programmability of heterogeneous multi-core multi-board systems. AXIOM proposes the use of the task-based OmpSs programming model, leveraging low-level communication interfaces provided by the hardware. Modular scalability will be possible thanks to a fast interconnect embedded into each module. To this aim, an innovative ARM and FPGA-based board will be designed, with enhanced capabilities for interfacing with the physical world. Its effectiveness will be demonstrated with key scenarios such as Smart Video-Surveillance and Smart Living/Home (domotics).Peer ReviewedPostprint (author's final draft

Structural Phase Transitions of Hybrid Perovskites CH₃NH₃PbX₃ (X = Br, Cl) from Synchrotron and Neutron Diffraction Data

Methylammonium (MA) lead trihalide perovskites, that is, CH3NH3PbX3 (X = I, Br, Cl), have emerged as a new class of light-absorbing materials for photovoltaic applications. Indeed, since their implementation in solar-cell heterojunctions, they reached efficiencies above 23%. From a crystallographic point of view, there are many open questions that should be addressed, including the role of the internal motion of methylammonium groups within PbX6 lattice under extreme conditions, such as low/high temperature or high pressure. For instance, in MAPbBr3 perovskites, the octahedral tilting can be induced upon cooling, lowering the space group from the aristotype Pm3¯m to I4/mcm and Pnma. The band gap engineering brought about by the chemical management of MAPb(Br,Cl)3 perovskites has been controllably tuned: the gap progressively increases with the concentration of Cl ions from 2.1 to 2.9 eV. In this chapter, we review recent structural studies by state-of-the-art techniques, relevant to the crystallographic characterization of these materials, in close relationship with their light-absorption properties

Crowd-sensing our Smart Cities: a Platform for Noise Monitoring and Acoustic Urban Planning

Environmental pollution and the corresponding control measurements put in place to tackle it play a significant role in determining the actual quality of life in modern cities. Amongst the several pollutant that have to be faced on a daily basis, urban noise represent one of the most widely known for its already ascertained health-related issues. However, no systematic noise management and control activities are performed in the majority of European cities due to a series of limiting factors (e.g., expensive monitoring equipment, few available technician, scarce awareness of the problem in city managers). The recent advances in the Smart City model, which is being progressively adopted in many cities, nowadays offer multiple possibilities to improve the effectiveness in this area. The Mobile Crowd Sensing paradigm allows collecting data streams from smartphone built-in sensors on large geographical scales at no cost and without involving expert data captors, provided that an adequate IT infrastructure has been implemented to manage properly the gathered measurements. In this paper, we present an improved version of a MCS-based platform, named City Soundscape, which allows exploiting any Android-based device as a portable acoustic monitoring station and that offers city managers an effective and straightforward tool for planning Noise Reduction Interventions (NRIs) within their cities. The platform also now offers a new logical microservices architecture

Modelling and simulation of paradigms for printed circuit board assembly to support the UK's competency in high reliability electronics

The fundamental requirement of the research reported within this thesis is the provision of physical models to enable model based simulation of mainstream printed circuit assembly (PCA) process discrete events for use within to-be-developed (or under development) software tools which codify cause & effects knowledge for use in product and process design optimisation. To support a national competitive advantage in high reliability electronics UK based producers of aircraft electronic subsystems require advanced simulation tools which offer model based guidance. In turn, maximization of manufacturability and minimization of uncontrolled rework must therefore enhance inservice sustainability for ‘power-by-the-hour’ commercial aircraft operation business models. [Continues.

Survey on Additive Manufacturing, Cloud 3D Printing and Services

Cloud Manufacturing (CM) is the concept of using manufacturing resources in a service oriented way over the Internet. Recent developments in Additive Manufacturing (AM) are making it possible to utilise resources ad-hoc as replacement for traditional manufacturing resources in case of spontaneous problems in the established manufacturing processes. In order to be of use in these scenarios the AM resources must adhere to a strict principle of transparency and service composition in adherence to the Cloud Computing (CC) paradigm. With this review we provide an overview over CM, AM and relevant domains as well as present the historical development of scientific research in these fields, starting from 2002. Part of this work is also a meta-review on the domain to further detail its development and structure