A study of the selection of microcomputer architectures to automate planetary spacecraft power systems

Performance and reliability models of alternate microcomputer architectures as a methodology for optimizing system design were examined. A methodology for selecting an optimum microcomputer architecture for autonomous operation of planetary spacecraft power systems was developed. Various microcomputer system architectures are analyzed to determine their application to spacecraft power systems. It is suggested that no standardization formula or common set of guidelines exists which provides an optimum configuration for a given set of specifications

Process of designing robust, dependable, safe and secure software for medical devices: Point of care testing device as a case study

This article has been made available through the Brunel Open Access Publishing Fund.Copyright © 2013 Sivanesan Tulasidas et al. This paper presents a holistic methodology for the design of medical device software, which encompasses of a new way of eliciting requirements, system design process, security design guideline, cloud architecture design, combinatorial testing process and agile project management. The paper uses point of care diagnostics as a case study where the software and hardware must be robust, reliable to provide accurate diagnosis of diseases. As software and software intensive systems are becoming increasingly complex, the impact of failures can lead to significant property damage, or damage to the environment. Within the medical diagnostic device software domain such failures can result in misdiagnosis leading to clinical complications and in some cases death. Software faults can arise due to the interaction among the software, the hardware, third party software and the operating environment. Unanticipated environmental changes and latent coding errors lead to operation faults despite of the fact that usually a significant effort has been expended in the design, verification and validation of the software system. It is becoming increasingly more apparent that one needs to adopt different approaches, which will guarantee that a complex software system meets all safety, security, and reliability requirements, in addition to complying with standards such as IEC 62304. There are many initiatives taken to develop safety and security critical systems, at different development phases and in different contexts, ranging from infrastructure design to device design. Different approaches are implemented to design error free software for safety critical systems. By adopting the strategies and processes presented in this paper one can overcome the challenges in developing error free software for medical devices (or safety critical systems).Brunel Open Access Publishing Fund

Microservice-Based Integration Framework for a Back-Office Solution

Dissertação de Mestrado em Engenharia InformáticaNot long ago, monolithic applications ruled among production servers – these applications had massive scopes which made them difficult to maintain, with constraints of libraries shared between modules and where every change or update is attached with big downtimes. To stray from this approach, enterprises chose to divide their big applications into smaller ones with fewer responsibilities, a clearer notion of boundaries and for the better part of it, more maintainable and scalable. The microservice approach allows enterprises to better divide themselves among teams that follow the full stack and spectrum of development in each application, from the persistence layer through the API and to the client, and from planning, through development to later support. The project exposed in this paper enlightens the scenario of an e-commerce platform’s back-office - where the implementation of a strangler pattern divided a large monolithic application into smaller microservices – leaving the door open for the integration of the multiple client applications to interconnect. The proposed solution intends to integrate the various systems of Jumia and take on this exposed opportunity, resorting to a microservice architecture and integration patterns with the objective of easing the flow of operations for processes that involve several management tools.Recentemente, o desenvolvimento de aplicações mudou à escala mundial, os sistemas distribuídos permitiram a introdução de um novo paradigma. Este paradigma baseia-se na redução de uma grande aplicação (monólito) em pequenos sub-módulos (micro-serviços) que comunicam perfeitamente entre si como se de uma única aplicação se tratasse. Este paradigma veio também refrescar as estruturas internas das empresas, ao distribuir os diversos serviços entre equipas, de forma a que cada uma delas esteja presente em todo o ciclo de vida das aplicações, desde o conceito até ao lançamento, passando pelo desenvolvimento e posterior manutenção e suporte da mesma. As mesmas equipas são também responsáveis por toda a stack que cada micro-serviço contém partindo da user interface (UI), passando por toda a API que contém a lógica de negócio até à camada de acesso de dados. Esta nova abordagem oferece algumas vantagens quando comparada com outras soluções disponíveis no mercado, tais como a liberdade de cada um dos serviços em ser desenvolvido nas tecnologias e linguagens que melhor se adequam ao seu propósito, sem que estejam presas a uma decisão tomada numa ocasião anterior para um propósito diferente ou a restrições de dependências incompatíveis entre si. Sendo que um dos principais problemas da computação distribuída é a possível indisponibilidade de cada um dos seus intervenientes, a arquitetura orientada a micro-serviços (microservice architecture, MSA) prevê que cada um dos seus serviços esteja contido no seu contexto (bounded context) e que disponha de todos os dados que lhe correspondem, desta forma a indisponibilidade de qualquer serviço não deve impactar o desempenho de nenhum dos seus pares. A reduzida dimensão de cada um destes serviços permite a existência de processos de deploy mais rápidos o que acaba por se refletir em downtimes mais reduzidos. Outra das vantagens da redução das dimensões e dos contextos de cada um dos serviços é a sua fácil manutenção, uma vez que o código se torna mais conciso e específico ao propósito que prevê cumprir. A modularidade dos micro-serviços permite-lhes também ajustar o número de réplicas de cada um deles de forma independente de acordo com as necessidades e previsões de volume de tráfego a cada momento. Apesar de todas as vantagens acima expostas, uma MSA traz consigo também alguns desafios tais como os testes de integração, debugging, deploying, retrocompatibilidade com outros serviços, entre outras abordadas em maior detalhe neste documento. O projeto exposto neste documento é um projeto proposto pela Jumia, uma empresa que disponibiliza uma plataforma de comércio online no continente africano. Esta plataforma está disponível em onze países africanos com mais de cem armazéns espalhados por todo o continente e que conta com mais de cinco mil colaboradores espalhados pelo mundo. Tal como muitas outras empresas no mercado a Jumia idealizou os seus processos de operações numa aplicação única que controlava todos os fluxos de negócio e continha em si toda a informação de armazenamento, produtos, entregas, pagamentos, encomendas entre outras. Rapidamente a aplicação de back-office da Jumia tornou-se insustentável e, tal como tinha sido executado noutras empresas do mesmo ramo, foi implementado um strangler pattern. Desta forma tornou-se possível fazer uma separação de dependências gradualmente, isolando cada um dos processos de negócio num serviço independente que persiste todos os dados necessários para a execução de cada uma das operações. No entanto, a implementação deste padrão deu origem a uma lacuna nos processos da empresa, uma vez que cada um dos serviços possui o seu user interface, algumas das operações requerem que os agentes de operações transitem entre aplicações, e necessitem de se autenticar novamente. Este processo acaba por ter impacto no fluxo de operações, refletindo-se no número de encomendas processadas e por consequência nas receitas da empresa. O presente documento pretende explorar a oportunidade de negócio proposta, assim como os mais essenciais padrões de integração de micro-serviços, de forma a apresentar uma solução que consiga colmatar a lacuna apresentada sem pôr em causa a segurança das aplicações e as normas de conformidade exigidas. Esta proposta foi elaborada através da conceção de uma arquitetura orientada a micro-serviços de forma coreografada tendo como objetivo ser integrada nas diversas aplicações de Back-Office com recurso a uma biblioteca importada através do gestor do Node Package Manager

Fast Deep Matting for Portrait Animation on Mobile Phone

Image matting plays an important role in image and video editing. However, the formulation of image matting is inherently ill-posed. Traditional methods usually employ interaction to deal with the image matting problem with trimaps and strokes, and cannot run on the mobile phone in real-time. In this paper, we propose a real-time automatic deep matting approach for mobile devices. By leveraging the densely connected blocks and the dilated convolution, a light full convolutional network is designed to predict a coarse binary mask for portrait images. And a feathering block, which is edge-preserving and matting adaptive, is further developed to learn the guided filter and transform the binary mask into alpha matte. Finally, an automatic portrait animation system based on fast deep matting is built on mobile devices, which does not need any interaction and can realize real-time matting with 15 fps. The experiments show that the proposed approach achieves comparable results with the state-of-the-art matting solvers.Comment: ACM Multimedia Conference (MM) 2017 camera-read

Integrating emerging cryptographic engineering research and security education

Unlike traditional embedded systems such as secure smart cards, emerging secure deeply embedded systems, e.g., implantable and wearable medical devices, have larger “attack surface”. A security breach in such systems which are embedded deeply in human bodies or objects would be life-threatening, for which adopting traditional solutions might not be practical due to tight constraints of these often-battery-powered systems. Unfortunately, although emerging cryptographic engineering research mechanisms have started solving this critical problem, university education (at both graduate and undergraduate level) lags comparably. One of the pivotal reasons for such a lag is the multi-disciplinary nature of the emerging security bottlenecks (mathematics, engineering, science, and medicine, to name a few). Based on the aforementioned motivation, in this paper, we present an effective research and education integration strategy to overcome this issue at Rochester Institute of Technology. Moreover, we present the results of more than one year implementation of the presented strategy at graduate level through “side-channel analysis attacks” case studies. The results of the presented work show the success of the presented methodology while pinpointing the challenges encountered compared to traditional embedded system security research/teaching integration

The Massive Remote Sensing Data Organization and Management Strategies

With the continuous development of earth observing technology of China, Remote sensing image data has characteristics of large volume, multisource, multi-type and multi-resolution, finding a way to store, manage, and publish the data is a big challenges. This paper proposes a massive Remote sensing tile data organization and management strategy based on spatial database, design a data distribution and node management strategy to solve the massive remote sensing data organization and management problem

The development of a multi-layer architecture for image processing

The extraction of useful information from an image involves a series of operations, which can be functionally divided into low-level, intermediate-level and high- level processing. Because different amounts of computing power may be demanded by each level, a system which can simultaneously carry out operations at different levels is desirable. A multi-layer system which embodies both functional and spatial parallelism is envisioned. This thesis describes the development of a three-layer architecture which is designed to tackle vision problems embodying operations in each processing level. A survey of various multi-layer and multi-processor systems is carried out and a set of guidelines for the design of a multi-layer image processing system is established. The linear array is proposed as a possible basis for multi-layer systems and a significant part of the thesis is concerned with a study of this structure. The CLIP7A system, which is a linear array with 256 processing elements, is examined in depth. The CLIP7A system operates under SIMD control, enhanced by local autonomy. In order to examine the possible benefits of this arrangement, image processing algorithms which exploit the autonomous functions are implemented. Additionally, the structural properties of linear arrays are also studied. Information regarding typical computing requirements in each layer and the communication networks between elements in different layers is obtained by applying the CLIP7A system to solve an integrated vision problem. From the results obtained, a three layer architecture is proposed. The system has 256, 16 and 4 processing elements in the low, intermediate and high level layer respectively. The processing elements will employ a 16-bit microprocessor as the computing unit, which is selected from off-the-shelf components. Communication between elements in consecutive layers is via two different networks, which are designed so that efficient data transfer is achieved. Additionally, the networks enable the system to maintain fault tolerance and to permit expansion in the second and third layers